Bitcoin against US dollar Sina Finance Net

1. bitcoin used to be synonymous with overnight wealth. In 2017, bitcoin had a record high price, with the highest value of about $20000
according to the data of coindesk digital currency trading platform, the price of bitcoin once fell below US $6000 in 18 years, which has dropped by 70% compared with the highest value of US $20000 in 2017

"the price movements we are seeing now may seem drastic, but they are quite normal for this market." Etiro's senior market analyst, MATI Greenspan, wrote in an email to CNBC

with the decline of bitcoin, most digital currencies are affected, and other digital currencies are not much better. Most digital currencies are down by more than 10%. But in the long run, the future of digital currency is worth looking forward to.

2. Bitcoin is priced in US dollars. Bitcoin and the US dollar are in a reverse relationship.

3. Because bitcoin has no credit guarantee, there is no hope that it can become a circulating currency in the future. So there is no value. It has nothing to do with the dollar. It can't replace the dollar.

4. The global economic downturn has brought great pressure on the stock market and other financial markets. The currency market does not have a good bottoming process at present. It is likely to hit a new low again and enter the bottom grinding stage after bottoming out.

5. Manual shooting skills of SLR camera
1. Take close-up pictures of small still objects, such as flowers, birds and insects:
use AV file, the aperture should be f5.6 or below, the focal length should be more than 50, and try to shoot within 1m to make the background virtual
if the light is good, ISO 100, if the light is bad, ISO should be within 400<

2. Shooting people:
basically use a large aperture (within f5.6) and a focal length of more than 50 mm. The shooting distance depends on the whole body, half body and big head, which makes the background virtual. Use AV file
good light, iso100, bad light, iso400
people in motion use tracking to reflect the sense of motion (see the shooting of moving objects below for details)<

3. Shooting:
AV file, use the appropriate aperture, above F8, the focal length is arbitrary, but generally the wide-angle end has distortion, use it as appropriate<

4. Shooting night scene:
upper tripod, AV gear, custom white balance or incandescent lamp, aperture above F8, small aperture can make the light proce starlight effect, use the reflector pre rising function to rece the vibration caused by the reflector lifting after pressing the shutter; And cover the viewfinder with the square cover on the strap to prevent stray light from entering from the back and affecting the image quality; ISO 200, as far as possible to make the exposure time longer, so that some people who have no intention to walk away from the screen disappear, leaving no traces, clean the scene
for example, when taking a square with people coming and going, you can use a very small aperture of about F20 and iso100. In this way, the exposure time will be very long, and the moving figures will not stay in the photos! The square will be clean<

5. Shooting fireworks:
using shutter line and B shutter, you can shoot multiple fireworks overlapping effect<

6. Shooting things:
when the light is good: AV, the aperture size should be handled according to the circumstances; Large depth of field can be obtained by using aperture above F8, and shallow depth of field can be obtained by using small aperture
if you want to have a very dynamic effect, you can use the TV gear, the shutter is about 1 / 30, when you focus and press the shutter, the lens will follow the object at an appropriate speed, which will proce a very dynamic effect
poor lighting: we can only handle it according to our own discretion, plus use the follow-up camera<

7. Shooting running water or fountain:
using TV and about 1 / 50 shutter speed, you can shoot Satin effect. If you use too fast shutter speed, the fountain will shoot discontinuous water drops<

8. Taking photos at night:
use tripod to adjust white balance, and automatically or custom white balance; iso100-400 AV gear, aperture about F8, use slow synchronous flash, rear curtain flash mode; At this time, the flash will flash twice, press the shutter to flash once, and flash again before the end of exposure, so don't leave before flashing twice
in this way, the characters can be clear and the background neon is beautiful, so that the background will not be too dark e to insufficient exposure< No matter what you shoot, don't shoot with the maximum aperture unless you want to keep a safe shutter
2. Please use the aperture of F8 ~ F11 as much as possible when shooting scenery
3. The maximum aperture can be reced by 1-2 levels when taking close-up of people and still life
4. The safety shutter should be controlled above the reciprocal of the focal length as far as possible. The wide-angle shutter should also be more secure at more than 1 / 30 second. If the shutter is insufficient, please increase the aperture or ISO<

metering method:
1. Don't measure the light to the sky or the darkest place. Go to the middle value
2. According to your subject matter, make good use of the metering mode (balance metering, point metering, central key metering...)
3. If the light measurement is not accurate, please use AE lock to expose and lock the gray things around you before shooting
4. Try not to measure the light on white or black objects, otherwise remember to rece eV for black and increase eV for white<

EV is exposure compensation.
exposure compensation is also an exposure control method, which is commonly used in ± If the ambient light source is dim, the exposure value (such as + 1eV, + 2eV) can be increased to highlight the clarity of the picture
most of the small digital cameras adjust the exposure compensation through the menu
in the process of shooting, if you press half of the shutter, the LCD will display pictures similar to the final effect picture, focusing and exposure will start. The exposure at this time is exactly the exposure of the final picture. If the picture is obviously bright or dark, it means that the automatic metering accuracy of the camera has a large deviation, and the exposure compensation should be enforced, but sometimes the brightness displayed ring shooting is different from the actual shooting result. Digital camera can browse the picture immediately after shooting, at this time, you can more accurately see the brightness of the picture, there will be no difference. If the shooting result is obviously bright or dark, it is necessary to re shoot and force the exposure compensation
the shooting environment is dim, and the brightness needs to be increased. When the flash cannot work, the exposure can be compensated and the exposure can be increased appropriately. For exposure compensation, if the photo is too dark, increase the EV value. Every 1.0 increase in EV value is equivalent to doubling the amount of light intake. If the photo is too bright, decrease the EV value. Every 1.0 decrease in EV value is equivalent to doubling the amount of light intake. The compensation interval can be adjusted in 1 / 2 (0.5) or 1 / 3 (0.3) units according to different cameras
when the white object to be photographed looks gray or not white enough in the photo, it is necessary to increase the exposure. In short, "the whiter the object is, the more white the object is." this seems to run counter to the basic principles and habits of exposure. In fact, it is not. This is because the main body of the camera is often the center of the light measurement, and the White main body will make the camera mistakenly think that the environment is very bright, As a result, the exposure is insufficient, which is also a common problem for most beginners
because the shutter time or aperture size of the camera is limited, it is not always able to reach the 2eV adjustment range, so the exposure compensation is not omnipotent, and it may still be underexposed in too dark environment. At this time, it is necessary to consider cooperating with the flash or increasing the ISO sensitivity of the camera to improve the brightness of the picture
generally speaking, the smaller the brightness contrast of the scene, the more accurate the exposure, otherwise, the larger the deviation. The grade of the camera is high and low. If the grade is high, the metering is more accurate, and if the grade is low, the deviation will be increased. If it is a traditional camera, the tolerance of film is relatively large, and the exposure deviation will not have a big problem within a certain range, but the CCD tolerance of digital camera is relatively small, and slight exposure deviation may affect the overall effect
in a word, the adjustment of exposure compensation is determined by experience and sensitivity to color. Users must compare the image quality, clarity, restoration degree and noise size under different exposure compensation to get the best picture

note:
the aperture in Canon's manual refers to the F value. The larger the aperture, the greater the depth of field
generally speaking, aperture refers to aperture, which is inversely proportional to F. the larger the aperture, the smaller the depth of field
AV -- aperture priority auto exposure
TV -- shutter priority auto exposure
AE auto exposure
AF auto focus
AF-S -- single auto focus, the same as saf. The opposite is continuous autofocus
MAF - monitor AF, which can shorten the focusing time. The camera will adjust the focus before half pressing the shutter button, so that you can compose with the adjusted focus. When the shutter button is half pressed and AF locking is completed, the focus will be locked
ev - exposure value, which is usually used in exposure compensation
ISO sensitivity. Each difference of sensitivity is equivalent to the corresponding exposure value of aperture or shutter
brother, if you have time, go to ZhongGuanCun video forum and see the forum.

6.

It can be seen from the figure:

1. From the distribution box to the lamp, there are three lnpe

2. An N-In line, when the switch appears, the number of poles will be increased. For example, when the lamp reaches the secondary switch, there are three lines between the lamp and the switch. That is, one incoming line, two outgoing lines, a total of three

There are three wires from one switch to another

4. Among the same group of lamps controlled by the same switch, there are three lnpe

5. Between different groups of lamps controlled by the same switch, l n plus the number of groups of lamps behind the line. If there are other switches connected below, add another L line that does not pass through the switch

extended data

the basic return route of common control lines is composed of the following parts

1. Power supply circuit: the power supply of power supply circuit includes AC380V and 220V

2. Protection circuit: the working power supply of protection (auxiliary) circuit includes single-phase 220, 36V or DC 220, 24V, etc., which can protect electrical equipment and lines from short circuit, overload and voltage loss, and is composed of fuse, thermal relay, voltage loss coil, rectifier component and voltage stabilizing component

Signal circuit: the circuit that can timely reflect or display the normal and abnormal working state information of equipment and circuit, such as signal lamps with different colors, sound equipment with different sounds, etc

Automatic and manual circuit: in order to improve the work efficiency, electrical equipment is generally equipped with automatic link, but in the installation, debugging and emergency treatment, the control circuit also needs to be set with manual link, through the combination switch or transfer switch to realize the automatic and manual mode conversion

Braking and parking circuit: the control link of cutting off the power supply of the circuit and taking some braking measures to make the motor stop quickly, such as energy consumption braking, power supply reverse connection braking, reverse pull reverse connection braking and regenerative power generation braking, etc

7. Regal money is a pyramid scheme, which is different from the mainstream currencies such as bitcoin, Ruitai and Laite. The following is the disclosure of the media:
in the case, the cheated citizens all bought different amounts of "Regal money" on the Internet. In the end, they were unable to contact the payee, and all the websites were closed, which directly led to property losses
captain Zhang said that after the police investigation, it was found that most of the servers of this kind of financial management website were located outside China, which brought great difficulties for the police to investigate and crack down
in this case, all the cheated people learned about "Regal coin" through the "Regal 888" wechat group, and almost all of them were victims of "Regal coin" and were introced to the group one by one
captain Zhang also said that in this case, the cheated person was not allowed to trade within the first month after buying one yuan for one "Regal coin", but after one month, he could buy and sell at will
as more and more people put in money, the price of "Regal money" will be raised, some people will withdraw when they buy, and some people who invest in advance will withdraw when they taste the sweetness. Most of the subsequent "takers" dream of continuing to appreciate and buy in large quantities. When the organizers feel that there is enough money, they will run away Daqing (www.daqing.com)