Decentralization of NBS

Publish: 2021-04-21 10:04:47

1、 On the basis of systematic field geological survey and detailed indoor research, the latest metallogenic theory and prospecting methods are adopted to study the Baolige silver gold deposit, chaganaobao iron zinc deposit and alhada lead zinc silver deposit in Jilin Province, as well as the peripheral granitoids by means of Geochemistry and isotope dating, In this paper, the geological background, geological characteristics, temporal and spatial distribution of these deposits and rocks are analyzed, the metallogenic model of these deposits is discussed, and the relationship between magmatic activity and mineralization of metal deposits is discussed. Finally, the prospecting direction is put forward. The research content includes the following aspects

(1) fully collect and collate the previous geological, geophysical and geochemical, aerial remote sensing data, establish the research focus and research methods, and summarize the regional metallogenic geological background and metallogenic regularity

(2) taking Baolige silver gold deposit, chaganaobao iron zinc deposit and alhada lead zinc silver deposit in Jilin Province as the key dissecting objects, on the basis of systematic field geological survey, the formation geological background, deposit characteristics and metallogenic stages of these deposits are identified

(3) advanced analytical and testing techniques were used to analyze the major, rare earth and trace elements of the representative samples of the above deposits, and sulfur, lead, rubidium strontium and samarium neodymium isotopes of single mineral or whole rock samples, so as to explore the source of ore-forming materials and the formation mechanism of the deposits

(4) geological survey was carried out on the surrounding rock bodies of the above deposits, major, rare earth and trace element analysis was carried out on the representative samples of the rock bodies, and sulfur, lead, rubidium strontium and samarium neodymium isotopic analysis was carried out on the single mineral or whole rock samples, so as to find out the geochemical characteristics, magma source and tectonic environment of each rock body, The relationship between magmatism and metallization is discussed

(5) SHRIMP U-Pb dating of zircons in each rock mass can accurately determine the diagenetic age of the rock mass and provide age evidence for regional magmatic activity

(6) through the analysis of the genesis of the deposit, the dynamic background of diagenesis and mineralization, the age of diagenesis and mineralization, and the source of metallogenic materials, the metallogenic model of the area is preliminarily established, and the prospecting direction is put forward

For the convenience of writing, this paper focuses on the main test process, test method, steps, instrument conditions and some important calculation formulas involved in this book. Except for the source, the major elements, rare earth and trace elements in the data are tested by the national geological testing center, the sulfur isotope is tested by the Isotope Laboratory of the Institute of mineral resources, Chinese Academy of Geological Sciences, and the lead, rubidium strontium and samarium neodymium isotopes are tested by the analysis and testing research center of Beijing Institute of Geological Sciences, SHRIMP U-Pb dating of zircons was performed in Beijing ion probe center, Institute of geology, Chinese Academy of Geological Sciences

(1) determination of major elements: SiO 2 , Al 2 o 3 , TFE 2 o 3 , Na 2 O, K 2 O, Cao, MgO, TiO 2 , MnO, P 2 o 5 < GB / T 14506.28-1993

step: weigh 0.5000 g of sample, use anhydrous lithium tetraborate and nitric acid as oxidant, melt into glass sheet at about 1200 ℃, and use X-ray fluorescence spectrometer (XRF) to determine SiO 2 , Al 2 o 3 , TFE 2 o 3 , Na 2 O, K 2 O, Cao, MgO, TiO 2 , MnO, P 2 O and other elements

method precision: different matrix and different content of national first-class geochemical reference materials were selected for determination, and the method precision RSD was less than (2% - 8%)

instrument model: X-fluorescence spectrometer (Physics 3080e). Detection limit: 0.05%

The detection method of FeO is based on GB / T 14506.14-1993

step: weigh 0.1000-0.5000 g of sample (the sample weight depends on the ferrous oxide content of the sample) into a PTFE crucible, add hydrofluoric acid and sulfuric acid to decompose the sample, and titrate the ferrous oxide content with potassium dichromate standard solution

The RSD was less than 10%. Detection limit: 0.05%

Detection method of

3. H 2 o +

detection basis: GB / T 14506.2-1993

step: weigh the sample in the bottom ball of the double ball tube, heat and burn the bottom ball and the sample under the blowtorch, and the crystallized water is cooled and condensed in another ball; When all the crystal water is burned out, separate the bottom ball and sample, weigh the ball tube with condensed crystal water and record the weight, then dry the tube and weigh again and record the weight. The difference between the two weights is the amount of crystal water

The RSD was less than 8%. Detection limit: 0.1%

4. CO 2 detection method

detection basis: GB 9835-1988

step: weigh the sample in the test tube, add mercuric thiocyanate, the CO 2 proced by decomposition will escape, and calculate the content according to the volume occupied by CO 2

The RSD was less than 8%. Detection limit: 0.10%

The calculation formula of Fe 2 o 3

magmatism and metal mineralization in dongwuzhumuqin banner, Inner Mongolia

(2) determination of trace elements

1. Determination of Cu, Rb, Nb, Ta, HF, Pb, Bi, th, u, Sn, La, CE, PR, Nd, SM, EU, Gd, TB, Dy, Ho, er, TM, Yb, Lu Y

test basis: DZ / T 0223-2001

step: weigh 0.0250 g of sample into Teflon inner tank with closed sample dissolver, and add HF and HNO 3 ; Put it into the steel sleeve, keep it at 190 ℃ for 24 h, take it out and cool it, steam it on the electric heating plate, add HNO 3 and seal the sample again for 3 h. The solution is transferred into a clean plastic bottle, and the solution is determined by ICP-MS

method precision: different matrix and different content of national first-class geochemical reference materials were selected for determination, and the method precision RSD was less than 10%

detection instrument: ICP-MS (Excel)

The detection limit of rare earth elements was 0.05 × The detection limits of other elements are shown in Table 1-1

Table 1-1 list of detection limits of some elements by ICP-MS

2. Determination of Zn, Sr, Zr, Ba by X-ray fluorescence spectrometry

detection basis: JY / T 016-1996

step: weigh 4 g of sample, evenly put it into the low-pressure polyethylene plastic ring, put it on the press, and press the sample into test piece slowly. The standard sample and the tested sample were prepared by the same method. It was determined by X-ray fluorescence spectrometer

method precision: different matrix and different content of national first-class geochemical reference materials were selected for determination, and the method precision RSD was less than 5%

detection instrument: X-ray fluorescence spectrometer (rix2100)

detection limit: < 5 × 10^-6

The determination of Au was based on dzg 20.03-1987

steps: 10 g samples were collected and dissolved by Wang Shui, then adsorbed by foam plastics and released by thiourea, and determined by graphite furnace atomic absorption spectrometry. p>

instrument model: atomic absorption spectrophotometer (PE aa-100)

detection limit: 0.0003 × 10^-6

The determination of Ag was based on dzg 20.10-1990

step: weigh 0.5-1.0 g sample, decompose with HCl + HNO 3 + HClO 4 + HF, then extract with MIBK in 10% HCl medium, and determine with graphite furnace atomic absorption spectrometry

The RSD was less than 15%

instrument model: atomic absorption spectrophotometer (pe-3030)

detection limit: 0.03 × 10^-6

Sulfur isotope analysis of metal sulfides the test samples were prepared by using Cu 2 o as oxidant and determined by mat-251 mass spectrometer. The analysis accuracy was better than that of vcdt international standard ± 0.2‰

The analysis process of lead isotope samples is as follows: 1. Weigh a proper amount of samples and put them into a polytetrafluoroethylene crucible, then add hydrofluoric acid and perchloric acid to dissolve the samples. After the sample was decomposed, it was evaporated to dryness, then added hydrochloric acid to dissolve and evaporate to dryness, and added 0.5 nhbr solution to dissolve the sample for lead separation; ② The dissolved sample was dissolved and poured into the pretreated strong basic anion exchange resin for lead separation. The resin was eluted with 0.5 nhbr solution, then eluted with 2 NHCl solution, and finally eluted with 6 NHCl solution. The elution solution was evaporated to dry for mass spectrometry determination; ③ Lead isotope was measured by thermal surface ionization mass spectrometry. The instrument model is isoprobe-t, and the analysis accuracy is 1 μ The content of 204 Pb / 206 Pb is less than 0.05%, and 208 Pb / 206 Pb is generally less than 0.005%. The standard value of NBS 981 is:

magmatism and metal mineralization in dongwuzhumuqin banner, Inner Mongolia

the measurement value is:

magmatism and metal mineralization in dongwuzhumuqin banner, Inner Mongolia

the above measurement accuracy is less than 2 σ The plan

Rubidium strontium isotope

accurately weigh 0.1-0.2 g of powder sample into a low-pressure sealed sample dissolving tank, accurately add rubidium strontium diluent, and dissolve it with mixed acid (HF + HNO 3 + HClO 4 ) for 24 h. After the sample is completely dissolved, evaporate to dryness, add 6 mol / L hydrochloric acid to convert to chloride and evaporate to dryness. The solution was dissolved in 0.5 mol / L hydrochloric acid solution and centrifuged. The clear solution was put into a cation exchange column φ 0.5 cm × 15 cm，AG50W × RB was eluted with 1.75 mol / L hydrochloric acid solution, SR was eluted with 2.5 mol / L hydrochloric acid solution, evaporated and analyzed by mass spectrometry

Isoprobe-t thermal ionization mass spectrometer with single band, m + , adjustable multi Faraday receiver was used for isotope analysis. Mass fractionation was corrected by 86 Sr / 88 sR = 0.1194, and nbs987 was 0.710250 ± 7

SM Nd isotope

0.1-0.2 g powder sample was accurately weighed in a low-pressure sealed sample dissolving tank, SM nd diluent was accurately added and dissolved in mixed acid (HF + HNO 3 + HClO 4 ) for 24 h. After the sample is completely dissolved, evaporate to dryness, add 6 mol / L hydrochloric acid to convert to chloride and evaporate to dryness. The solution was dissolved in 0.5 mol / L hydrochloric acid and centrifuged. The clear solution was put into cation exchange column φ 0.5 cm × 15 cm，AG50W × The matrix elements and other elements were eluted with 1.75 mol / L hydrochloric acid solution and 2.5 mol / L hydrochloric acid solution, and the light rare earth elements were eluted with 4 mol / L hydrochloric acid solution and evaporated to dryness

Samarium neodymium was separated by P507 Extraction Resin, evaporated and converted to nitrate, and then analyzed by mass spectrometry

Isoprobe-t thermal ionization mass spectrometer with three bands, m + , and adjustable multi Faraday receiver was used for isotope analysis. The mass fractionation was corrected by 146 nd / 144 nd = 0.7219, and the standard measurement result was (0.512118) ± 3) 512110)

(4) SHRIMP U-Pb dating

the samples collected in the field were broken to 80-120 mesh. After washing the st with water, the magnetite and other magnetic minerals were removed with a magnet, and then the zircon was selected with heavy liquid, and finally the zircon was purified under a binocular lens. Zircon samples and laboratory standard samples were placed in epoxy resin, grinded until half of zircon was exposed, polished and cleaned to make sample targets for the study of transmission and reflection, cathodoluminescence and SHRIMP U-Pb dating. Cathodoluminescence and SHRIMP U-Pb dating in Institute of geology, Chinese Academy of Geological Sciences, Beijing, China

2. When the coil generates inced current, the total electromotive force of the coil is equal to the sum of the electromotive force generated by each coil. Generally speaking, the electromotive force of each turn in the coil is equal, and the electromotive force in series is equal to the average electromotive force multiplied by the number of turns.

3. You asked the right person! Spies just need to build more barracks! Just order a soldier first and then a t! Air defense is very important! Different countries have different usages! Antiaircraft guns should be built in the mine! Most people only attack that! The air defense will patrol there! Where is the second place for spies! The problem is how to avoid the dogs! You can attract them with some soldiers! Just let them on a map, then press T, then press Ctrl and numbers (if it's the same kind of soldier), if not, use that guy's method!

4. Red police have no secret, only the use of bug cheating method. All the secret books on the Internet are deceptive and useless.

The isotopic work of the deposit includes the analysis of radioactive uranium and lead isotopic ages and isotopic strontium ratios, as well as the determination of stable isotopes of carbon, hydrogen, oxygen and sulfur

The strontium isotope ratio of fluorite is determined by crushing the weighed sample to 200 mesh, placing it in a Teflon beaker, adding SR diluent and HF + HClO4 mixed acid to dissolve it, and then evaporating it to dryness after the sample is completely dissolved. Then the sample was dissolved and evaporated in HCl, and the solution was loaded into dowe × 50W × 8 (H +) (200-400 mesh) ion exchange column. The separation of Sr isotopic composition is based on SR interpretation, liquid absorption, evaporation and mass spectrometry

The strontium isotope ratio was measured by mat260 solid isotope mass spectrometer in the form of M 2 + ions and received by Faraday receiver. Sr isotopes were analyzed by single band analysis with TA 2 o 5 emitters. Sr isotope mass fractionation was corrected by 88 Sr / 86 sR = 8.37521. Results: nbs9 87 SrCO 3 87 Sr / 86 sR = 0.71035 ± 22 σ， The results show that the precision of determination is better than 0.1%, and the blank of SR process is 9 - 9 ~ 9 - 10 G

As a strontium isotope ratio,

is widely used in petrology to discuss petrogenesis. As for the minerals formed by hydrothermal mineralization, the ratio of 87 Sr / 86 SR has not been used to infer the material source of hydrothermal fluid. Based on the principle of exploration, the ratio of 87 Sr / 86 SR was determined for fluorite in Xiazhuang ore field, and the determination results are shown in table 9-15

Table 9-15 fluorite 87 Sr / 86 Sr ratio analysis results

from the 87 Sr / 86 Sr ratio of two fluorites of different generations, there is no obvious change between them. The fluorite 87 Sr / 86 SR of quartz, green fluorite and calcite assemblage in hydrothermal stage after uranium mineralization is 0.724468, However, in the uranium mineralization stage, the 87 Sr / 86 SR of purple fluorite is 0.721459, which is slightly lower than that of green fluorite. Can it be considered that the small change of 87 SR 86 SR is e to the differentiation of hydrothermal evolution

The carbon and oxygen isotopes of calcite were analyzed by 100% phosphoric acid method at 25 ℃ ± The water of CO 2 was removed by freezing method. As soon as the reaction bottle left the constant temperature water bath, it was immediately frozen with - 70 ℃ cold liquid. All CO 2 was collected by liquid nitrogen freezing method. The mass spectrum reference gas was purified CO 2 , which was measured by mat-251 mass spectrometer δ 13 C and δ 18 o value; The mass spectrometer is in the most priority technical state, and its measurement accuracy is better than 0.05 ‰. δ 13 C is based on PDB, δ 18 O was measured by PDB and smow δ 13 C and δ 18 o PDB and δ< The ‰ value of sup > 18 o v-flow is higher than the ‰

calcite is a kind of mineral widely developed and formed for a long time in the hydrothermal procts of Xiazhuang ore field. It can not only precipitate earlier than pitchblende, but also form simultaneously with pitchblende, and also precipitate in the late stage of hydrothermal solution. A total of 8 calcite samples were selected for the determination of carbon and oxygen. Most of the calcites in the eight samples were formed earlier or later than the hydrothermal stage of pitchblende, and also precipitated simultaneously with pitchblende. The color of calcite samples is red (R after sample number), black (B after sample number) and white (no after sample number). Their carbon and oxygen isotope measurements are shown in table 9-16

Table 9-16 carbon and oxygen isotope determination results of calcite. The carbon and oxygen isotopic compositions of calcite are determined by the isotopic fractionation of the equilibrium reactions. However, different forms of carbon compounds may have different sources, so different forms of carbon compounds can provide hydrothermal fluids with different 13C values of carbon. The change of T, F O 2 and pH value in the hydrothermal fluid will cause the thermal stress in the hydrothermal fluid δ 13 C value changed. The reason is that the bond energy of different carbon compounds is different, which will inevitably lead to the change of carbon and oxygen isotopes in the procts. For example, in the magmatic system, the abundance of CO and CS is always much smaller than that of CO 2 or CH4. Unfortunately, there is no experimental study on the rate of carbon isotope exchange reaction between CO and CO 2 or CH4, so it can only be analyzed according to the carbon isotope results of calcite

The carbon isotope of calcite can be seen from table 9-16, δ 13 CPDB ‰ varied from - 4.4 ‰ to - 7.5 ‰, while δ< The calcite with sup > 13 CPDB ‰ of - 4.4 ‰ is formed simultaneously with pitchblende. That is to say, the earlier and later mineralized calcites did not undergo carbon isotope fractionation e to the decrease of hydrothermal fluid temperature. And the calcite in mineralization period δ 13 CPDB = - 4.4 ‰ is significantly lower than the carbon isotope value of calcite formed before and after mineralization. This phenomenon is probably caused by the change of the ratio of oxidized carbon compounds and reced carbon compounds in the hydrothermal fluid, resulting in the enrichment of relative 13C in the mineralization stage. However, e to the change of oxygen fugacity of ore bearing hydrothermal fluid, the type of carbon compounds is constantly changing, so the carbon isotope of calcite is also changing in the mineralization stage, such as that of x471 δ13CPDB＝-7.2‰～-7.3‰

the oxygen isotope in calcite is the same as the carbon isotope, and the variation range of oxygen isotope in different stages of calcite is also small, which is based on the standard of smow δ< The values of sup > 18 o vary from + 10.1 ‰ to + 13.5 ‰, as shown in table 9-16 δ 18 osmow shows that the oxygen isotope value of mineralization stage is slightly lower than that of pre ore stage and post ore stage

According to the carbon and oxygen isotopic values of calcite in different stages, the equilibrium reaction of carbon isotope in hydrothermal fluid system does not change, so there is no obvious isotopic fractionation

(3) oxygen isotope of quartz and hydrogen isotope of its inclusion water quartz is the main associated gangue mineral of Xiazhuang ore field mineralization, which has long formation time, many color changes and large grain size structure changes. For this reason, the research group selected 8 quartz samples for oxygen isotope determination, and 7 of them were analyzed for hydrogen isotope in inclusion water at the same time

The oxygen isotope analysis method of gangue quartz and its inclusion water: firstly, put the sample in the vacuum drying oven, dry it at 105-110 ℃, weigh 12 mg of dried sample (weighing accuracy is 0.02 mg), send it to the bottom of the reactor which has been filled with Ar gas in advance with a special sampler, and then connect the reactor back to the vacuum system to remove Ar gas in the system, Add 5 times of sample BRF 5 and freeze with liquid nitrogen, then vacuum to 2.0 × 10 - 3 PA, remove the liquid nitrogen cup and heat it to 500 ~ 550 ℃. After the reaction, cool water is used to quickly rece the reactor to room temperature for oxygen extraction. The samples of CO 2 were analyzed by mat-251em mass spectrometer, and the accuracy of the mass spectrometer was 0.3 ‰

quartz inclusion is to extract H 2O and CO 2 (30 min) from primary fluid inclusion by heating explosion method, and then h 2 O is reacted with Zn at 400 ℃ for 30 min to proce H 2. The obtained H 2 sample is sent to mat-251em mass spectrometer for isotope analysis and mass spectrometer measurement δ The accuracy of D is ± 3 ‰, the international standard smow is adopted

The oxygen isotope of

quartz samples and the hydrogen isotope of their corresponding inclusions are listed in table 9-17

Table 9-17 hydrogen and oxygen isotope measurement results of vein quartz δ 18 o value shows that the oxygen isotope of quartz varies in different stages, which may be caused by three factors. That is to say, the evolution of hydrothermal fluid leads to different oxygen isotopes of vein quartz in different stages of crystallization and precipitation; The crystallization differentiation of oxygen-containing minerals in hydrothermal fluids at different stages leads to the change of oxygen isotope of quartz; The physical and chemical conditions of vein quartz in different stages are different, and the oxygen isotope of quartz in different stages is different e to the different crystal order of quartz

In the past, many researchers used oxygen isotope values measured by quartz and hydrogen isotope values of altered clay minerals proced by thermal action to calculate water content in fluid by fractionation equation between separation coefficient and temperature δ 18 O ‰, this fractionation equation only obeys the following equilibrium conditions, namely:

Guidong magmatic rocks and uranium mineralization in Nanling Mountain

that is to say, in the system of H 2 O and SiO 2 , the oxygen isotopic exchange between water and silica follows the 1 / T 2 . However, vein quartz in many uranium deposits can not meet the above equilibrium reaction relationship. Because the systems they are in are not simple h 2 O and SiO 2

In addition to the quartz composition of uranium vein, the isotopic equilibrium reaction exchange equation is used to calculate the hydrothermal fluid δ< Besides the doubt of sup > 18 O ‰, there is also the reliability of inclusion temperature measurement. The homogenization temperatures of the same mineral at the same stage measured by Chen Anfu (1982) and Zhang Jianfeng (2003) are compared (table 9-18)

Table 9-18 comparison of temperature measured by homogenization method δ 18 O ‰ value. The temperature change of homogenization method is probably caused by the inconsistency of determination of primary inclusions. Because "the evidence of primary inclusions is relatively rare" (h.l.barnes. 1979)

If the above reasons are not considered, the oxygen isotope fractionation equation of quartz water system in the temperature range of 250-500 ℃ by Matsuhisa (1979) and the oxygen isotope fractionation equation of quartz water system by Zhang Ligang (1985) are used to calculate the oxygen isotope fractionation of quartz in the hydrothermal system at 250 ℃ δ 18 Oh 2 O ‰ and their fractionation equations are as follows:

magmatic rocks and uranium mineralization in Guidong, Nanling Mountains δ< The values of sup > 18 Oh 2 O ‰ are shown in table 9-19

Table 9-19 in quartz water system δ 18 Oh 2 O ‰ calculation results

from the two fractionation equations in table 9-19, the oxygen isotope value in the effluent is a large range of variation, and the fractionation equation of Matsuhisa is the best δ 18 Oh 2 O ‰ changed from - 4.0 ‰ to 5.3 ‰. Calculation of Zhang Ligang's fractionation equation δ 18 Oh 2 O ‰ varied from - 5.0 ‰ to + 4.6 ‰. Obviously, the reason for this large-scale change is the same as that of the oxygen isotope values of gangue

In hydrothermal gangue minerals, calcite is purer than vein quartz in composition, and there is no obvious carbon isotope fractionation in calcite from pre ore stage, ore stage to post ore stage, and its oxygen isotope also shows the same characteristics as carbon isotope

6. Unknown_Error

7. XRD quantitative analysis method
from the application of internal standard equation or external standard equation, we can understand that it is possible and necessary to establish a standardized specific intensity database, so that we can use the intensity data of X-ray diffractometer for quantitative determination of phase at any time. Now jcpds has agreed to use corunm α- The reference specific intensity (RIR) is defined as the specific intensity I / icol of the strongest line of each phase to the strongest line of corunm, and the RIR is listed as the basic data of polycrystalline X-ray diffraction of the material and put into PDF card. Although the current collection of RIR is not rich enough, the establishment of RIR database is of great significance for the wide application of polycrystalline X-ray diffraction in phase quantitative analysis. According to the definition of RIR, its data value can be obtained by theoretical calculation or directly measured by experiment. At present, in addition to corunm, NBS also recommends several other materials (such as zinc oxide, rutile, Cr2O3 and CEO3) as reference materials for selection. The RIR of a material for different reference materials can be converted into the RIR relative to corunm, because the RIR of these reference materials for corunm is known
practical X-ray diffraction phase quantitative methods based on internal standard equation or external standard equation are all specific intensity methods. The premise of this kind of method is that there must be specific intensity data, that is, there must be pure samples (so-called standard samples) of the phase to be determined. This requirement is sometimes difficult to achieve, because some phases can not get pure samples for the determination of specific strength. Therefore, several other methods have been developed on the basis of equation (6.6). These methods do not require the preparation of standard samples in advance, such as standard free method, absorption / diffraction direct quantitative method, micro direct quantitative method and Compton scattering correction method, but these methods are not as common as the specific intensity method
X-ray diffraction phase quantitative method can directly determine each component phase in the sample, which has a wide range of applications. However, e to the weak diffraction intensity, it is difficult to detect a small amount of phase in the sample, that is, the sensitivity of the method is not high, and it is even less sensitive to the sample with large absorption coefficient, Generally speaking, the detection limit is not better than 1%

8. I have graated from high school. In high school, physics was my strong point and my favorite subject
physics in senior high school is not as difficult as you think. The whole knowledge about celestial bodies and Astronautics in senior high school is based on the two centers of gravity and centrifugal force (uniform circular motion)
if there is no major revision of the book, the two contents are discussed separately. The combination of the two is to dece a series of formulas and conclusions about space navigation. The formula of space travel is not new
if you can't dece the formula in the chapter of space navigation, you should still not understand the uniform circular motion and centrifugal force well. Especially the definition of angular velocity, ω( (angular velocity)= θ/ T to understand well, it is the same with the definition of velocity, which is the key to understand the linear velocity and period, because angular velocity can dece the linear velocity and period V (linear velocity) = R ω T (period) = 2 π r/v=2 π/ω With these two, it's easy to do
the formula of uniform circular motion
1, V (linear velocity) = s / T = 2 π r/T= ω r=2 π r/T=2 π RN (s for arc length, t for time, R for radius) 2 ω( (angular velocity)= θ/ t=2 π/ T=2 π n θ 3, t (period) = 2 π r/v=2 π/ω 4. N (speed) = 1 / T = V / 2 π r= ω/ two π 5. FN (centripetal force) = Mr ω^ 2=mv^2/r=mr4 π^ 2/T^2=mr4 π^ 2F ^ 26, an (centripetal acceleration) = R ω^ 2=v^2/r=r4 π^ 2/T^2=r4 π^ Do you understand the phenomenon of centrifugation? This is also the key. You can find a rope to tie a heavy object (such as a small stone), pull the rope in your hand and rotate the heavy object according to the circle to feel the centrifugal force and phenomenon
the key is: when the object is in centrifugal motion, it tends to deviate from the center of the circle. So there has to be a force to balance it. It can't fly away. If you let go of your hand, will the weight fly away
the laws of physics are widely used in the universe. Satellites around the earth and planets around the sun are actually the same truth. It's just like a heavy object tied by a rope. At this time, the force is not your hand, but the earth or the sun, and the force exerted by the earth or the sun is gravity
F = GMM / R ^ 2, this is the starting point of formula derivation in space navigation. If we grasp this point, are we afraid that we can not dece other formulas
the derivation of universal gravitation is pasted by me:
if the orbit of a planet is approximately regarded as a circle, the angular velocity of the motion of the planet can be determined from Kepler's second law, that is: ω= two π/ T (period) if the mass of the planet is m, the distance from the sun is r, and the period is t, then according to the motion equation, the force acting on the planet is Mr ω^ 2=mr4 π^ 2) In addition, from Kepler's third law, R ^ 3 / T ^ 2 = constant K & # 39; So the force along the direction of the sun is Mr (4) π^ 2/T^2=mk' four π^ 2) / R ^ 2 according to the relationship between the force and the reaction, the sun is also subjected to the same force. From the perspective of the sun, (mass of the sun m) (K & # 39&# 39; four π^ 2) / R ^ 2 is the force on the sun in the direction of the planet. Because it is a force of the same magnitude, the comparison of these two formulas shows that K & # 39; It includes the mass of the sun m, K & # 39&# 39; It includes the mass m of the planet. It can be seen that these two forces are directly proportional to the proct of the masses of the two celestial bodies, which is called universal gravitation. If we introce a new constant (called the gravitational constant), then we consider the mass of the sun and planets, as well as the previously obtained 4· π 2, then it can be expressed as gravitation = (GMM) / (R ^ 2) the gravitation between two ordinary objects is so small that we can't notice it, so we can ignore it. For example, two people with a mass of 60 kg, 0.5 meters apart, the gravitational force between them is less than one millionth of a Newton, and the force of an ant dragging a thin straw is 1000 times that of the gravitational force! However, in the celestial system, e to the great mass of the celestial body, gravitation plays a decisive role. In celestial bodies, the earth, whose mass is still very small, has a great influence on the universal gravitation of other objects. It binds human beings, atmosphere and all ground objects to the earth. It makes the moon and man-made earth satellites rotate around the earth without leaving. When making a circular motion on the surface of a planet, the universal gravitation can be regarded as gravity, with Mg = (GMM) / (R ^ 2) and GM = g (R ^ 2), which is the golden substitution formula
and Mr ω^ 2=mr4 π^ 2/T^2=mg This conclusion is only applicable to the surface of stars)
the key is to remember the gold substitution formula
about the exam, if there is a calculation problem in this chapter, the number will be huge, astronomical, but there is still a way to deal with the exam. I tell you that you must remember several common data: the mass of the earth, the mass of the sun, the orbit height of the synchronous satellite, the distance between the earth and the moon, and several cosmic velocities in the book. Remember that these are more useful than your questions, because common questions are measured around them. If you remember it, you don't need to forget it. Anyway, the accuracy of the final result is not high. If you want several digits, you can keep a few digits of the data you remember. Although a little speculative, ha ha, this is my experience
what I want to say is not to learn physics as mathematics. It's not the derivation of pure formulas, but it's closely related to life. It seems that many people treat physics as mathematics, which makes physics boring. In the future, when learning physics, we should read more experiments in textbooks. It's much more interesting to relate the phenomena mentioned to life, and it's much more cordial to understand them
there are also a lot of specific methods and techniques
it's not clear in a few words
I added you the network hi. If you agree, I will send you any information in the future
all of the above are told to you in the most popular language, not pasted casually

I wish you all the best in the exam& gt;_& lt;

9. Color knowledge

in the colorful world, color makes everything in the universe full of emotion and vitality. As the most common aesthetic form, color exists in all aspects of our daily life. Clothing, food, housing, transportation, use, people are almost all inclusive, and are closely related to color all the time

human feeling is the beginning of understanding. The light and sound of the objective world act on the sensory organs. Through the activities of the nervous system and brain, we have feelings and have a knowledge of external things and phenomena. Color is associated with human feelings (external stimulation) and human perception (memory, association, contrast, etc.). Color perception always exists in color perception, and there are few isolated color perception

People's color sense information transmission channels are light source, color object, eyes and brain, which are the four elements of people's color sense formation. These four elements not only make people feel color, but also are the conditions for people to judge color correctly. If one of the four elements is not true or changes in the observation, the color and its effect cannot be correctly judged

the radiation energy of light source and the reflection of objects belong to the category of physics, while the brain and eyes are the contents of physiological research, but color is always based on physics, and the sense of color always contains the reflection of the psychological and physiological effects of color, which makes people proce a series of comparisons and associations

the Committee on chromaticity of the Optical Society of America once defined color as a property of light other than the inhomogeneity of space and time, that is, the radiation of light can stimulate the retina and cause the scene obtained by the observer through vision. In our national standard gb5698-85, color is defined as: color is the visual characteristics caused by light acting on human eyes except image. According to this definition, color is a kind of visual characteristic that physical stimulation acts on human eyes, and human visual characteristic is controlled by brain, which is also a kind of psychological reflection. Therefore, color perception is not only related to the original color characteristics of an object, but also affected by time, space, appearance and the surrounding environment of the object, as well as by people's experience, memory, views, visual sensitivity and other factors

color comes from nature, but human beings combine the inspiration of natural color with natural or artificial color, which makes our life more colorful<

color mixing

A: primary color theory

three primary colors, the so-called three primary colors, means that any one of the three colors can not be proced by the mixing of the other two primary colors, and other colors can be mixed by the three colors according to a certain proportion. In chromatics, these three independent colors are called three primary colors

b: color mixing theory

color mixing can be divided into additive mixing and subtractive mixing. Color can also be mixed after entering the vision, which is called neutral mixing< (1) additive mixing

additive mixing refers to the mixing of colored lights. When two or more kinds of lights are mixed together, the brightness will be improved, and the total brightness of the mixed colors is equal to the sum of the brightness of the mixed colors. In the color light mixture, the three primary colors are vermilion, emerald green and blue violet. These three colors of light can not be proced by mixing other colors of light. However:

vermilion + emerald green = yellow light

emerald green + blue violet = blue light

blue violet + vermilion = purple light

yellow light, blue light and purple light are intermediate light

if white light can be proced by mixing only two kinds of color light, then the two kinds of light are complementary colors to each other. For example: red light and blue light; Green light and purple light; Blue violet light and yellow light< (2) subtractive mixing

subtractive mixing mainly refers to the mixing of pigments

after the white light passes through the colored filter, part of the light is reflected to absorb the rest of the light, recing part of the radiation power. The last light is the result of two times of light rection. Such color mixing is called subtractive mixing. Generally speaking, the dye with strong transparency has obvious light recing effect after mixing

the three primary colors mixed by subtraction are the complementary colors of the three primary colors mixed by addition, that is, the complementary colors of emerald green, red (magenta), blue purple, yellow (light yellow), and vermilion, blue (sky blue). When two primary colors are mixed, the resulting color is intermediate:

Red + blue = purple

Yellow + Red = orange

Yellow + blue = green

If two colors can proce gray or black, these two colors are complementary colors. When the three primary colors are mixed in a certain proportion, the resulting color can be black or black gray. In subtractive mixing, the more colors mixed, the lower the lightness and the lower the purity< Neutral mixing is a kind of visual color mixing based on human visual physiological characteristics, which does not change the color light or the luminous material itself, and the brightness of the mixing effect does not increase or decrease, so it is called neutral mixing

there are two ways of visual mixing:

A: color rotation mixing: two or more colors are placed on a disk and rotated rapidly by power to see new colors. The effect of color rotation mixing is similar to that of additive mixing in hue, but it is the average value of mixed colors in lightness

b: spatial mixing: when different colors are juxtaposed together, when their projection on the retina is small to a certain extent, these different color stimuli will act on the photoreceptor cells in the very adjacent parts of the retina at the same time, so that it is difficult for the eye to distinguish them independently, which will proce color mixing in vision. This kind of mixing is called spatial mixing

Color basis

to understand and use color, we must master the principles and methods of color inction and arrangement. One of the most important is to master the attributes of color
color can be divided into no color and color. The former is black and white. Gray, the latter such as red, yellow, blue and other colors
having color means having some or some hues in the spectrum, which is collectively referred to as tone. On the contrary, no color, no tone
no color, light and dark, white and black, also known as tone. The color representation is very complicated, but it can be determined by three groups of special micro values. One is color tone, that is, hue; The second is light and shade, which is lightness; Third, the color is strong, that is, purity, chroma. Lightness and chromaticity determine the state of color. It is called the three attributes of color. Lightness and hue are combined to form the color state of the second line, which is called hue. Some people understand lightness as hue, which is not comprehensive
lightness

when it comes to lightness, it's better to start with no color, because no color has only one dimension and is much more debatable The brightest is white and the darkest is black. The gray between black and white has the performance of light intensity. If divided by a certain interval, it constitutes the scale of light and shade. There is color that depends on its own lightness value, but also by adding and subtracting gray, white tone to adjust the light and shade
the Japanese color matching system (p.c.c.s.) uses nine levels, while mensaier uses eleven levels to indicate light and shade, and both use a series of numbers to indicate the rapid increase of lightness. The surface brightness of an object is related to the reflectivity of its surface. If there is more reflection and less absorption, it is bright; On the contrary, it is dark. Only 100% reflected light is ideal white, and 100% absorbed light is ideal black. In fact, there is no such ideal phenomenon around us, so people often regard the most ideal white magnesium sulfide crystal surface as the standard of white. In the p.c.c.s. system, black is' 1, gray is 2.4.3.5, 4.5.5.5, 6.5, 7.5, 8.5, and white is 9.5. The closer to white, the higher the brightness, the closer to black, the lower the brightness. Popular division, there are the highest, high, slightly high, medium, slightly low, low, the lowest seven levels. In the middle of the nine levels, if we add their dividing levels, that is, 2, 3, 4, 5, 6, 7.8 and 9, we will get seventeen brightness levels
when there is color, the brightness of purity is expressed by the corresponding brightness without color gray tone. The lightness is generally indicated by the vertical up and down. The top is white, the bottom is black, and then according to the feeling of hair tone difference level, into the gray tone‘ This vertical axis of light and shade, called achromatic axis, is the central axis of color stereo

hue

having color means that it contains color tones, namely group, yellow, blue and other color groups, which are called hues
the initial basic hues are: red, orange, yellow, green, blue and purple. One or two intermediate colors are inserted in the middle of each color. The hues of the head and tail are red, orange red, yellow orange, yellow, yellow green, green, green blue, blue-green, blue, violet and purple according to the spectral order. Twelve basic hues can be obtained by adding an intermediate color to red, purple, red and purple
the tone changes of these twelve hues are uniform in spectral color sense. If we further find out the intermediate colors, we can get 24 hues. If we circle the red, orange, green, blue and purple bands of the spectrum and insert half a frame between red and purple to form a circular hue relationship, it is called a hue ring. Take the middle color between the basic colors, that is, the twelve color ring. A further step is the 24 hue ring. In the circle of the hue ring, the colors are arranged at different angles, so the distance between each color of the twelve hue ring is 30 degrees. Twenty four color phase ring, the distance between each color is 15 degrees
the p.c.c.s system makes a more regular uniform name and symbol for hues. Among them, red, orange, yellow, green, blue and purple refer to their "positive" colors (of course, the understanding of the so-called positive colors is not the same everywhere). The positive color is represented by a single capital letter, the equal amount of mixed color is represented by two parallel capital letters, the unequal amount of mixed color is mainly represented by capital letters, and the color is represented by small letters. The only exception is that blue and purple use v instead of BP. V is the first letter of violet. It is easy to use and memorize for the first time
it is obvious that the Japanese division and naming of colors in this way is in line with Munsell's ten colors and twenty colors. Munsell system is based on red, yellow, green, blue and purple, which is called yellow red. Therefore, the 24 colors of P, C, C and s systems are also classified into ten categories,

chromaticity

one hue and tone, and there are also strong and weak points. Take red for example, there are bright pure red without impurities, astringent and dry like "withered rose", there are also lighter pink. Their hues are the same, but the strength is different, generally known as (SA + URA + lon) or chromaticity. The higher the chromaticity, the purer and more colorful the color; The lower the chromaticity is, the more astringent and turbid the color is. Solid color is the highest chroma level
denotes chromaticity. Generally, the horizontal axis is used. Taking the vertical axis of no color as a point, it extends in a certain hue direction of the hue ring. According to the chromaticity, it is divided into several levels from low to high. The P, C, C and s system is divided into nine levels, with s as its scale unit. The lowest is is

10. Summary of physics formula in Senior High School The motion of particles (1) ---- linear motion
1) uniformly variable linear motion
1. Average velocity V flat = s / T (definition) 2. Useful inference vt2-vo2 = 2As
3. Velocity V T / 2 = V flat = (VT + VO) / 2 4. Final velocity V T = VO + at
5. Velocity V S / 2 = [(VO 2 + vt2) / 2] 1 / 2 6. Displacement S = V flat t = VO + at 2 / 2 = VT / 2T
7. Acceleration a = (VT VO) / T In the positive direction, a and VO are in the same direction (accelerating) a & gt; 0 In reverse, a & lt; 0}
8 Δ s＝aT2 ｛ Δ Main physical quantity and unit: initial velocity (VO): M / S; Acceleration (a): M / S2; Final velocity (VT): M / S; Time (T) seconds (s); Displacement (s): m; Distance: meters; Speed unit conversion: 1m / S = 3.6km/h
note:
(1) the average velocity is a vector
(2) the acceleration is not necessarily large when the velocity is large
(3) a = (VT VO) / T is only a measure, not a determinant
(4) other related contents: particle, displacement and distance, reference frame, time and time [see Volume I P19] / S-T diagram, V-T diagram / speed and speed, instantaneous speed [see Volume I p24]
2) free falling body motion
1. Initial velocity VO = 0.2. Final velocity VT = GT
3. Falling height h = GT2 / 2 (calculated from VO position downward) 4. Dection vt2 = 2GH
note:
(1) free falling body motion is a uniformly accelerated linear motion with zero initial velocity and follows the law of uniformly variable speed linear motion
(2) a = g = 9.8 m / S2 ≈ 10 m / S2 (the acceleration of gravity is smaller near the equator, and it is smaller in the high mountains than in the plain, and the direction is vertical and downward)< (3) vertical throwing motion
1. Displacement S = vot-gt2 / 2 2. Final velocity VT = VO GT (g = 9.8m / S2 ≈ 10m / S2)
3. Useful inference vt2-vo2 = - 2GS 4. Maximum rising height HM = VO2 / 2g (calculated from the throwing point)
5. Round trip time t = 2VO / g (time from throwing to the original position)
note:
(1) whole process processing: it is uniform deceleration linear motion with upward as the positive direction, The acceleration is negative
(2) segmented processing: upward is uniform deceleration linear motion, downward is free falling motion, with symmetry
(3) the rising and falling processes are symmetrical, such as the velocity equivalent at the same point and the opposite direction
2. Motion of particles (2) --- curvilinear motion Gravity
1) horizontal throwing motion
1. Horizontal velocity: VX = VO 2. Vertical velocity: vy = GT
3. Horizontal displacement: x = VOT 4. Vertical displacement: y = GT2 / 2
5. Movement time: T = (2Y / g) 1 / 2 (usually (2H / g) 1 / 2)
6. Combined velocity: VT = (VX2 + vy2) 1 / 2 = [VO2 + (GT) 2] 1 / 2
angle between combined velocity direction and horizontal β: tg β＝ Vy / VX = GT / V0
7. Combined displacement: S = (x2 + Y2) 1 / 2,
angle between displacement direction and horizontal α: tg α＝ Y / x = GT / 2VO
8. Horizontal acceleration: ax = 0; The acceleration in vertical direction: ay = g
note:
(1) the horizontal projectile motion is a curve motion with uniform velocity change, and the acceleration is g, which can be generally regarded as the combination of the horizontal linear motion with uniform velocity and the vertical free falling motion
(2) the movement time is determined by the falling height h (y) and has nothing to do with the horizontal throwing speed 3 θ And β The relationship between them is TG β＝ 2tg α
(4) time t is the key to solve the problem 5) When the direction of velocity is not in the same line as the direction of resultant force (acceleration), the object will move in a curve
2) uniform circular motion
1. Linear velocity v = s / T = 2 π R / T 2. Angular velocity ω＝Φ/ t＝2 π/ T＝2 π F
3. Centripetal acceleration a = V2 / r = ω 2r＝(2 π/ T) 2R 4. Centripetal force fcenter = MV2 / r = m ω 2r＝mr(2 π/ T)2＝m ω 5. Period and frequency: T = 1 / F 6. Relationship between angular velocity and linear velocity: v = ω R
7. Relationship between angular velocity and rotational speed ω＝ two π Main physical quantities and units: arc length (s): meter (m); Angle Φ)： Radian (RAD); Frequency (f): Hz; Period (T): second (s); Speed (n): R / S; Radius & reg;: Meter (m); Linear velocity (V): M / S; Angular velocity ω： rad/s Centripetal acceleration: M / S2
note:
(1) the centripetal force can be provided by a specific force, a resultant force, or a component force. The direction is always perpendicular to the velocity direction and points to the center of the circle
(2) the centripetal force of an object in uniform circular motion is equal to the resultant force, and the centripetal force only changes the direction of velocity, but does not change the size of velocity, so the kinetic energy of the object remains unchanged, the centripetal force does not do work, but the momentum changes constantly< Kepler's third law: T2 / R3 = K (= 4) π 2 / GM) {R: orbital radius, t: period, K: constant (independent of the mass of the planet, depends on the mass of the central celestial body)}
2. Law of gravitation: F = gm1m2 / R2 (g = 6.67) × 10-11N• 3. Gravity and acceleration of gravity on celestial bodies: GMM / r2 = mg; G = GM / r2 {R: celestial body radius (m), M: celestial body mass (kg)}
4; ω＝( GM/r3)1/2 T＝2 π( R3 / GM) 1 / 2 {M: mass of central celestial body}
5. The first (second and third) cosmic velocity V1 = (g earth r earth) 1 / 2 = (GM / R earth) 1 / 2 = 7.9km/s; V2＝11.2km/s V3 = 16.7km/s
6. GMM / (R + H) 2 = M4 π 2 (r earth + H) / T2 {h ≈ 36000km, H: height from the earth's surface, R earth: radius of the earth}
note:
(1) the centripetal force required for celestial body motion is provided by universal gravitation, f direction = f ten thousand
(2) the mass density of celestial bodies can be estimated by using the law of universal gravitation< (3) the geostationary satellite can only operate over the equator, and its operation cycle is the same as the earth rotation cycle
(4) when the orbit radius of the satellite becomes smaller, the potential energy becomes smaller, the kinetic energy becomes larger, the velocity becomes larger, and the period becomes smaller
(5) the maximum orbit speed and minimum launch speed of the earth satellite are 7.9km/s< (3) force (common force, composition and decomposition of force)
1) common force
1. Gravity g = Mg (vertical downward, g = 9.8m / S2 ≈ 10m / S2, acting point at the center of gravity, applicable to the earth's surface)
2. Hooke's law f = KX {direction along the recovery deformation direction, K: stiffness coefficient (n / M), X: deformation variable (m)}
3. Sliding friction f = μ FN {is opposite to the relative motion direction of the object, μ： Friction coefficient, FN: positive pressure (n)}
4. Static friction 0 ≤ fstatic ≤ FM (opposite to the direction of relative motion of the object, FM is the maximum static friction)
5. Gravitation f = gm1m2 / R2 (g = 6.67) × 10-11N• The electrostatic force F = kq1q2 / R2 (k = 9.0) × 109N• Electric field force F = EQ (E: field strength n / C, Q: electric quantity C, the electric field force of positive charge is the same as the direction of field strength)
8. Ampere force F = bilsin θ θ When l ⊥ B: F = bil, B / / L: F = 0)
9. Lorentz force F = qvbsin θ θ When v ⊥ B: F = QVB, V / / B: F = 0)
note:
(1) the stiffness coefficient K is determined by the spring itself
(2) friction coefficient μ It has nothing to do with the pressure and contact area, but is determined by the material characteristics and surface condition of the contact surface
(3) FM is slightly larger than that of FM μ FN, generally regarded as FM ≈ μ FN;
(4) other related contents: static friction (size and direction) [see P8 in Volume 1]
(5) symbol and unit of physical quantity B: magnetic inction intensity (T), l: effective length (m), I: current intensity (a), V: velocity of charged particle (M / s), Q: charge of charged particle (charged body) (c)
(6) the direction of Ampere force and Lorentz force are determined by left-handed rule
2) the composition and decomposition of forces
1. The composition of forces on the same line is in the same direction: F = F1 + F2, reverse: F = F1-F2 (F1 & gt; F2)
2. Synthesis of mutual angular force:
F = (F12 + F22 + 2f1f2cos) α) 1 / 2 (cosine theorem) F1 ⊥ F2: F = (F12 + F22) 1 / 2
3. Range of resultant force: | F1-F2 | ≤ f ≤| F1 + F2 |
4. Orthogonal decomposition of force: FX = fcos β， Fy＝Fsin ββ Is the angle TG between the resultant force and the x-axis β＝ FY / FX)
note:
(1) the composition and decomposition of forces (vectors) follow the parallelogram rule
(2) the relationship between resultant force and component force is equivalent substitution relationship, which can replace the joint action of component force with resultant force, and vice versa
(3) in addition to the formula method, the drawing method can also be used to solve the problem. In this case, the scale should be selected and the drawing should be strict
(4) when the value of F1 and F2 is fixed, the angle between F1 and F2 is smaller α The larger the angle, the smaller the resultant force
(5) the combination of forces on the same straight line can take the positive direction along the straight line, and the direction of the force can be represented by a sign, which is simplified to an algebraic operation< (4) dynamics (motion and force)
1. Newton's first law of motion (Law of inertia): an object has inertia and always keeps in a state of uniform linear motion or static state until it is forced to change this state by an external force
2. Newton's second law of motion: F = ma or a = f = ma / MA {determined by the external force, 3. Newton's third law of motion: F = - F & acute{ The negative sign indicates the opposite direction, F, F & acute; The practical application: recoil motion}
4. The balance of common force F = 0, the promotion of {orthogonal decomposition method, the principle of three forces}
5. Overweight: FN & gt; G. Weight loss: FN & lt; G {acceleration direction downward, both weightless, acceleration direction upward, all overweight}
6. Applicable conditions of Newton's law of motion: applicable to solving low-speed motion problems, applicable to macro objects, not applicable to dealing with high-speed problems, not applicable to micro particles [see p67 in Volume I]
note: the state of equilibrium refers to the state of static or uniform linear, Or rotate at a constant speed< Vibration and wave (mechanical vibration and propagation of mechanical vibration)
1. Simple harmonic vibration f = - KX {F: restoring force, K: proportional coefficient, X: displacement, negative sign indicates that the direction of F is always opposite to x}
2. Simple penlum period T = 2 π( L / g) 1 / 2 {L: penlum length (m), G: local gravity acceleration value, the tenable condition: penlum angle θ& lt; 100; l>& gt; R}
3. Forced vibration frequency characteristics: F = f driving force
4. Resonance conditions: F driving force = f solid, a = max, resonance prevention and application [see Volume I P175]
5. Mechanical wave, shear wave and longitudinal wave [see Volume II P2]
6. Wave velocity v = s / T = λ f＝ λ/ In the process of t {wave propagation, a period propagates one wavelength forward; The wave velocity is determined by the medium itself}
7; 20℃:344m/s 30℃:349m/s( Acoustic wave is a longitudinal wave)
8. The condition of wave diffraction (wave continues to propagate around the obstacle or hole): the size of the obstacle or hole is smaller than the wavelength, or the difference is not significant
9. The interference condition of wave: the frequency of two trains of waves is the same (the difference is constant, the amplitude is similar, and the vibration direction is the same)
10. Doppler effect: e to the mutual movement between the wave source and the observer, Results in the difference between the transmitting frequency and the receiving frequency of the wave source {close to each other, the receiving frequency increases, otherwise, it decreases}
note:
(1) the natural frequency of the object is independent of the amplitude and the driving force frequency, and depends on the vibration system itself
(2) the strengthening zone is where the peaks meet or the valleys meet, while the weakening zone is where the peaks meet
(3) the wave only propagates the vibration, the medium itself does not move with the wave, it is the transmission

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