Combing BTC

1. In order to understand the technical principle of bitcoin, we need to understand two important cryptographic techniques: hash code: it converts a long string into a fixed length string, and its conversion is irreversible, that is, it is impossible to guess the original string from hash code. Sha256 is mainly used in bitcoin protocol
public key system: corresponds to a public key and a private key, keeps the private key in the application and publishes the public key. When Party A transmits information to Party B, it can use Party A's private key to encrypt the information, and Party B can use Party A's public key to decrypt the information, so as to ensure that the third party cannot impersonate Party A to send the information; At the same time, when Party A transmits information to Party B, it is encrypted with Party B's public key and sent to Party B, and then Party B decrypts it with his own private key, so as to ensure that the third party cannot eavesdrop on the communication between the two people. RSA is the most common public key system, but the lliptic curve digital signature algorithm is used in bitcoin protocol. What's the difference between cash and bank account? Bitcoin is an electronic currency in BTC. In this article, it is also used to refer to the whole bitcoin system. Like opening an account in a bank, the corresponding concept in bitcoin is address. Everyone can have one or more bitcoin addresses, which are used to pay and collect money. Each address is a string that starts with 1. For example, I have two bitcoin accounts, and. A bitcoin account is uniquely determined by a pair of public key and private key. To save the account, you only need to save the private key file. Unlike bank accounts, banks keep all transaction records and maintain the book balance of each account, while bitcoin's transaction records are jointly maintained by the whole P2P network through a pre agreed protocol. How much money is in my account address? Although the current account balance can be seen by bitcoin software, unlike banks, there is no place to maintain the book balance of each address. It can only calculate the account balance in real time through all historical transactions. How do I pay? When I pay from address a to address B of the other party, the payment amount is e. at this time, both parties will announce the transaction information to each network node, telling address a to pay to address B, and the payment amount is e. In order to prevent the third party from forging the transaction information, the transaction information will be encrypted with the private key of address A. at this time, the network node receiving the transaction information can use the public key of address a to verify that the transaction information is indeed sent by address a. Of course, trading software will help us do these things, we just need to input the relevant parameters in the software. What will the network node do after receiving the transaction information? This is the most important part of the bitcoin system, which needs to be elaborated. For the sake of simplicity, only bitcoin protocol has been implemented. In the current version, each network node will save all transaction information synchronously. There are two kinds of transaction information in history, one is & quot; Verified & quot; The transaction information, that is, the verified transaction information, is stored in a series of "blocks". Each & quot; block" Is the previous & quot; bock" The ID of each block is the hash code of the hash code of the block and the new transaction information (see an actual block). The other category refers to those who also & quot; Unverified & quot; The transaction information just paid above belongs to this category. When a network node receives new unverified transaction information (possibly more than one), it can calculate the book balance of each address at that time because the node keeps all the transaction information in history, so it can calculate whether the transaction information is valid, that is, whether there is enough balance in the payment account. After eliminating the invalid transaction information, it first takes out the last & quot; block" Then, the unverified transaction information is combined with the ID, and a verification code is added to form a new "block". It needs a lot of calculation to build a new block, because it needs to calculate the verification code, so that the above combination becomes a block, that is, the first several bits of the hash code of the block are 1. At present, the first 13 bits need to be 1 (generally, the specific method is uncertain), which means that if the block is generated by enumeration method, the average number of enumerations is 16 ^ 13. Using CPU resources to generate a block is called "gold mining", because the proction of the block will get a certain reward, and the reward information has been included in the block. When a network node generates a new block, it will broadcast to other network nodes. However, this network block may not be accepted by the network, because it is possible that other network nodes have proced the block earlier. Only the earliest block or the block with the largest number of subsequent blocks is valid, and the remaining blocks are no longer used as the initial blocks of the next block. How does the other party confirm that the payment is successful? When the payment information is distributed to the network node, the network node begins to calculate whether the transaction is valid (that is, whether the account balance is enough to pay), and attempts to generate blocks containing the transaction information. When six blocks (one direct block and five subsequent blocks) contain the transaction information, the transaction information is considered "verified", so that the transaction is formally confirmed, and the other party can confirm the successful payment. A possible problem is that I will pay the balance of address a to address B, and at the same time pay to address C. If I only verify that the single comparison transaction is valid. At this point, my way of cheating is to generate six blocks including B to B and six blocks including C to C before the truth is revealed. Because I need a very long CPU time to generate a block, compared with the whole network, the probability of my cheating success is very small. What is the motivation of network nodes to proce blocks? As can be seen from the above description, in order to make the transaction information effective, the network node needs to generate 1 and 5 subsequent blocks to contain the transaction information, and such block generation is very CPU intensive. How to let other network nodes help to proce blocks as soon as possible? The answer is very simple. The agreement stipulates that BTC will be rewarded for the address where the block is proced, as well as the Commission promised by both parties. At present, the reward for procing a block is 50btc, which will be halved every four years in the future. For example, the reward will be 25btc from 2013 to 2016. Is the transaction anonymous? Yes, and No. All bitcoin transactions are visible. We can check all transaction records of each account, such as mine. But what's different from the banking monetary system is that everyone's account itself is anonymous, and everyone can open many accounts. In general, anonymity is not as good as it claims. But bitcoin has another advantage in doing black market trading: it can't be frozen. Even if the police trace a bitcoin address, there is nothing they can do unless they trace the computer used by the exchange based on the Internet address. How to ensure that bitcoin does not depreciate? Generally speaking, in the case of equivalent trading activities, the value of money is inversely proportional to the amount of money issued. Unlike the traditional money market, the central bank can determine the amount of money issued. Bitcoin does not have a central issuing institution. Only by procing blocks can we get a certain amount of BTC currency. Therefore, bitcoin's new amount of money depends on: 1. The speed of procing blocks: bitcoin's agreement stipulates that the difficulty of procing blocks is fixed at an average of 2016 every two weeks, about 10 minutes. Moore's law of doubling CPU speed every 18 months will not speed up the proction of block. 2. The number of rewards for block proction: at present, 50 BTC is awarded for each block proced, which is halved every four years. In 2013, 25 BTC is awarded, and in 2017, 12.5 BTC is awarded. Considering the above two factors, bitcoin's currency issuing speed is not controlled by any single node in the network. Its protocol makes the currency stock known in advance, and the maximum stock is only 21 million BTC

2. There is no push behind bitcoin. There is no reason to go up. Speculative things should be treated with caution. Let's just say one thing: why does not a country participate in the mining of such a high-yield thing? Just think about it.

3. virtual currency, or more formally, digital currency. Although it carries the words of currency, it should be a kind of digital financial asset. Its value comes from the application of blockchain technology in payment, clearing, notarization, digital verification and other aspects, which brings efficiency improvement and cost rection
as you can understand it, it's like the stock of these technology service providers. As these technologies become more and more widely used, these virtual coins will become more and more valuable
bitcoin, which appeared in 2009, is the first kind of virtual currency in the world. It is also the first time that it has applied the blockchain technology which is popular all over the world
after bitcoin, there are many imitators in the market. They either improved on the basis of bitcoin, or put forward more grand technical ideas than bitcoin. Virtual currency, which is common in other markets and considered as "regular army" by instry insiders, is collectively referred to as competitive currency. Together with bitcoin, it forms the whole digital currency market, with a total market value of nearly 100 billion US dollars
there are thousands of virtual currencies in the market, most of which are risky; In addition, there are many MLM coins that are simply for the purpose of deceiving people< In order to help you avoid being cheated, the following is a brief introction to the main "regular army":
1. Bitcoin (BTC)
bitcoin is the first virtual currency in the world, with a total of 21 million. At present, more than 16 million bitcoins have been "g up", with a total market value of about US $45 billion, equivalent to half of the total market value of all virtual coins. It is well deserved to be the number one in the coin circle
bitcoin has been accepted as payment currency by hundreds of thousands of businesses around the world; In addition, bitcoin has also become a common money raising currency in various blockchain technology startups. Therefore, with the increasing demand for bitcoin, the value of bitcoin is likely to grow in the long run
2. Eth is regarded as "bitcoin version 2.0" and is the most likely competitor to surpass the market value of bitcoin. Some time ago, the market value of bitcoin was close to that of bitcoin. However, e to the price rection in the recent month, the market value of bitcoin is only about half of that of bitcoin
Ethernet coin was born in the summer of 2014. It is issued on the Ethereum blockchain, which is different from bitcoin. Ethereum blockchain is a decentralized application platform, which solves the problems of bitcoin's technical limitation in currency application and insufficient function expansion, so it has great technical advantages
3. Bitcash (BCH)
BCH inherits a small part of bitcoin's legacy, the name of bitcoin's cash is also good, and the image logo also inherits a part of bitcoin. The ecology of BCH is also good
BCH pursues to be a world currency and an underlying platform for chain application. BCH is actively deploying the main chain expansion and developing the two-tier network to realize the ideal
the whole ecology should be made efforts from two aspects. The first direction is the expansion of the main chain, payment experience and function improvement. Capacity expansion is the guarantee to keep the certainty of monetary transaction fees very low. Improving the payment experience, including popularizing zero confirmation, pre consensus, and possibly shortening block time, are all evolving towards a better payment experience. The main chain function is perfect, including Op_ Return expansion, token issuance, new opcode addition
with the expansion of BCH main chain function, BCH based applications can be developed. The most famous are the decentralized microblog like memo, the paid download seed application like joystream, and the decentralized encrypted communication like Keyport
the second direction is to develop layer-2 network. Build a new blockchain based on BCH network, such as wormhole and kenoken, which are similar to Ethereum network based on BCH. BCH undertakes more complex block chain functions, such as notification contract, through two-layer network. The competition direction of BCH layer 2 network is to compete with the side chain of BTC
4. Lightning bitcoin (LBTC)
bitcoin has been developing for 10 years. In this decade, bitcoin has experienced three important splits, and now it has become four kinds of currencies. The first is BTC, which has inherited most of bitcoin's heritage; The second is BCH; The third is BSV and the fourth is LBTC
LBTC was born to break the power monopoly of big miner and bitcoin core bitcoin, introce more new features and functions for bitcoin, and greatly improve its performance. Lightning bitcoin (LBTC) is a peer-to-peer e-cash system, which is an innovative experiment based on bitcoin. It uses the dpos consensus mechanism based on utxo to separate the voting right and accounting right, so that the token will not be kidnapped by any party. It is a global value Internet transmission protocol with high speed, low handling charge and high scalability. Due to the adoption of dpos consensus mechanism, users can participate without professional mining machines, achieving real decentralization
the above four are the most mainstream bifurcated versions of bitcoin protocol. They are also investment procts that can realize your desire of soaring wealth. Senior managers can play with them, but the premise is that you need to be prepared for huge losses - because they are very volatile
for Xiao, I would like to say: Although virtual currency is a secret weapon for ordinary people to counter attack the sudden wealth, it's very difficult for you to make a lot of money from it
in addition, at present, the price of virtual bitcoin is at a high level, and it can not be ruled out that it will mainly be sideways in 2019. At this time, I think it is a good choice to some other mainstream bifurcation currencies, such as BCH, BSV and LBTC.

4. no MLM is selling the concept and earning a head fee. The digital currency can be used to trade, it has its own value. There are a lot of people investing in digital currency now, but it is suggested to go to big trading platforms, such as hot money pro, which only has reliable digital currency online, so the risk can be reced.

6. I am a parent of a senior three student in Jiangsu Province. I understand your feelings very well. Usually, if you don't do well in the test, don't shout too much. It's the most important to find the problem and remedy it. In fact, the score of 75% in each course is also very high. For example, the total score is 750, 75% is 560, and you can go to a good university. Primary school, junior high school, if 100 points you only 75 points, others must think that your performance is not good enough, but high school if you average 75%, should be a better result. Don't worry too much. After all, it's still more than eight months old
don't blame your mother for her bad attitude. She should encourage you just like your father, but you can't ask your parents too much. Your parents have no experience as senior three parents. In China, only parents are employed without training

starting from the first round: 30 excellent experiences in the college entrance examination. Their experience is sparking with wisdom, especially the test of practice has proved the truth of these ideas and statements, which can be used for reference in our examination. Here are 30 of them for the students who are preparing for the college entrance examination
1. Carpet sweeping. Let's review the basic knowledge first. The pursuit is as comprehensive as possible, without omission, even reading materials or text notes. We should have the spirit of locusts and be invincible
2. Find the connection between knowledge. Find the connection between the knowledge of each chapter. The pursuit is from the local to the overall, grasp the local from the overall. Think more and try more< Third, the use of knowledge. Do questions, do all kinds of questions. Strive to practice the use of knowledge through various forms of problem solving. Master a variety of problem-solving ideas, exercise the ability to analyze and solve problems through problem-solving
Fourth, pick up "dregs". That is to find out the leakage and make up for the deficiency. Through the repetition of review, on the one hand, strengthen knowledge, strengthen memory, on the other hand, look for errors, make up for omissions. To grasp the knowledge more comprehensively and deeply and improve the ability
fifth, "flipping pancakes". Review is like a "pancake", you need to turn a few to be mature, do not turn a few to be raw. Memory also needs to be strengthened, and it is difficult to remember without repeated reinforcement. Therefore, it takes two or three times to review< 6. Foundation or foundation. There are a lot of things to do when we review, there are a lot of review materials waiting for us to do, but we still need to grasp the fundamental. What is fundamental? Basics! Basic knowledge, basic skills and skills are the main requirements of syllabus and examination. On the basis of "double base", we should grasp the basic thinking of solving problems. The idea of solving problems is a kind of starting point for analyzing and solving problems based on solid basic knowledge. No matter how difficult the problem is, it is nothing more than the synthesis or variation of basic things. In the limited review time, we have to make a wise choice, that is to grasp the foundation. Do you know? Shuangji's psychological foundation will be much better
remember: foundation, foundation, or foundation< To learn liberal arts, we should "die" to "live". In history, there are many things to recite, such as characters, events, dates, key points of some historical materials and so on. Some materials, can only be "dead" remember, to repeatedly strengthen memory. History is a subject with a large amount of mechanical memory. But in the examination, we should use the materials flexibly, which means we should not only remember firmly, but also understand and understand vividly. It means to "die" first and then "live". Not only to study history, geography, politics, but also to study theory, chemistry and life, we need to "die" to "live"< 8. "Try and win.". This is a line from the TV series "don't cry at the age of 17". Examination to have a good attitude, to have courage“ "Try to fight" is a positive attitude of participation, a mental state of daring to fight and win, and a momentum of challenging and surpassing. Whether in review or in the examination room, we need to be full of emotion and spirit, not depressed and depressed, excited but not depressed, brave but not cowardly“ Those who just want to win can't win, but those who don't want to lose win“ "Want to win" is our pursuit of the "upper limit", do not want to lose is our "lower limit"“ "Want to win" is a kind of hard work, so it is more tense and passive, "don't want to lose" is a kind of defensive, so it is more calm and active. Obviously, the latter is more relaxed. In a relaxed state of mind, often play normal and achieve good results< 9. "A person with healthy psychological quality should do two things: to cheer up when he is depressed, and to be able to excuse himself when he is under too much pressure, so that he will not be upset." People's subjective initiative enables people to control and grasp themselves, so as to make their mental state in the best condition. The opposite and the opposite is the dialectics of all things. The frailty of psychological quality is the abandonment of subjective initiative, while the healthy psychological quality makes us more "substantial" - we can adjust our mood and mentality to overcome the difficulties< The college entrance examination is fundamentally a comprehensive investigation of a person's strength and psychological quality Strength is the foundation and capital, and psychological quality is the condition for us to exert our strength and capital. If you have capital, you have to know how to use it. We can't do business without capital, and we can do business with capital and lose money< Review is to accumulate strength and capital, while examination is to make full use of it and make the most profit. One examinee said: "I am always confused in the exam, but I always rank in the top in the big exam. Maybe I have a good psychological adjustment?" It is true that the most terrible is the big test big confused, small test small confused, do not test not confused< 12. Strong subjects are stronger, weak subjects are not weaker; Strong subjects have weaknesses, and weak subjects have strengths. " In the examination of several subjects, a person has strong and weak, too normal. The strategy of review is to strengthen and supplement the weak. Some students are only weak, ignoring the strong; Some students give up the weak and specialize in the strong. On the whole, there is no wisdom. There should be no "moisture" in the strong, but breakthrough in the weak. It is probably a very clever strategy to make up for the weak on the basis of making the strong stronger< It is necessary to make up for the poor subjects to reach the upper middle level; Good ones should be highlighted to make them a real advantage. " The reason here is similar to the above, and it is also a strategy to treat one's own strengths and weaknesses. The entrance examination of senior high school is a "team competition", which aims to win the overall situation instead of paying attention to one thing and losing the other
14. "You have to remember what you should remember, but don't remember what you can't remember." In order to rece the burden of memory, there is no need to play with your life where you can be lazy - there should be enough to memorize! According to the characteristics of knowledge, between memory and understanding, knowledge can be divided into four types: understanding without memory; Just remember what you don't need to understand; Only memory can understand; Only memory can remember. Our achievement here is the rolling review method of "the principle of minimum output". First review the first chapter, then review the second chapter, and then review the first and second chapters together; Then review the third chapter, then review the first three chapters together, and so on, just like "rolling". This review method needs a certain amount of time, but the review is relatively firm, because it conforms to the rule of memory, the effect is good
fifteen, "over review method". Memory has a "law of diminishing returns", that is, with the increase of memory times, the efficiency of reviewing the memorized materials is decreasing. In order to counteract this "decline", some students adopted the "excessive review method", that is, they used 10 minutes to memorize the materials, and then 3 minutes to memorize them - forming a kind of "excess", in order not to be affected by the "decline"
16. Review wrong questions, once understand, never let go. Failure is the mother of success. That's the meaning of getting more from failure and less from success. What fails should be our motto
17. To master examination skills“ Basic questions, all right; Middle grade questions, no waste; Try your best to deal with more difficult problems, even if you don't regret your mistakes. " This is the strategy to answer questions when facing the examination paper. Examination questions are always difficult and easy, which can be divided into basic questions, middle-level questions and more difficult questions. The above strategy is very wise and desirable, "easy questions do not lose points, difficult problems do not zero points." It is often not easy to keep what should be kept, because it is easy to be careless when encountering easy problems. So it is also very important to make clear the easy questions without losing points. Difficult problems can not be scored zero, which is a reflection of the enterprising spirit of never giving up. We should work hard to the last point and the last minute
eighteen, "bypass the roadblocks and kill them again." It's hard to avoid problems in the exam. When you still can't break it, you should take the initiative to give up in time. Don't waste time with it endlessly. After doing other problems, it is very likely that the idea will be opened up and become active, and then it will be done in reverse. Examination time is limited, in the limited time to get more points, but also to talk about strategy< 19. Take a research attitude towards the test questions Weakening the score consciousness may be a good way to relieve the tension. Therefore, to have a research attitude towards the examination questions will make us better play the best level in the examination room. It's sometimes better to have an ordinary heart than to have an extraordinary heart< It's better to make fewer mistakes than to make more skillful ones This is a famous Korean chess player Lee Chang Ho's experience. What he talked about is playing chess, but it is not without reference to our examinations, especially for those students who study better and get better grades. It is essential to achieve excellent grades, create high scores and rece mistakes< The key is to cultivate interest. Bruner, an American ecator, said: "the best stimulus for students is their interest in learning materials." As for "interest is the best teacher" has long been popular. If you have no interest but have to do what you have to do, why are you interested and happy? For example, politics is more theoretical and boring, so we should cultivate more interest in politics. At ordinary times, we should pay more attention to the country's major policies. When we encounter problems, we will also imagine ourselves as a civil servant and imagine how civil servants solve problems. In this way, politics will be vivid. In fact, politics is around us
23. Don't take homework home. The class time is very serious and the class efficiency is very high. Learning things require that they solve all the time in school, and strive not to take home homework. In this way, the time back home is their own, and they can do what they like to do
24. Like to take notes and organize them neatly and comprehensively. It's very important to grasp the knowledge system, sort out and review the context of knowledge. With notes, you can often do focused review, review the old and learn the new< Don't pass the college entrance examination

7.

In instrialized countries, a major pipeline network has been built to transport crude oil to refineries at suitable locations inland, and the pipeline network is also used to transport petroleum procts from refineries to consumption centers. The oil pipeline is a large-diameter pipe, which can transport a large amount of oil. The annual transportation capacity can reach tens of millions of tons. Along the pipeline, pumping stations are built every 60-100 kilometers to maintain the pressure of oil in the transportation. The route of oil transportation in pipeline from proction plant to refinery. The velocity is 2 m / s. Pipeline transportation means that in general, there will be no serious oil leakage accident. In fact, once the pipeline is damaged e to accident or man-made damage, the pump can be stopped, which can effectively limit the pollution. However, if the pipeline ownership country does not implement effective supervision on the pipeline, things may become particularly serious. Oil contains acidic gases (CO2 and H2S), which are more or less corrosive, so the pipeline will be damaged from the inside, and if it is not replaced in time, the pipeline will leak

Basically speaking, the pipeline construction needs to be negotiated according to geopolitics, and the dialogue between the pipeline crossing countries proces a kind of cooperation agreement in order to solve disputes.. The construction of major pipelines across many countries needs to go through fierce negotiations. After these negotiations, the geopolitics of energy demand is based on politics, and the comprehensive analysis of geography, history and social science is carried out on different scales (ranging from one country to international analysis). It analyzes and studies the significance of geographical location, politics, economy and strategy. The meaning of geography here is the relationship between geographical location, scope, function and region and reserves. And politics. For example, let's look at the problem of new oil resources in Central Asia - what happened there, what happened around the Caspian Sea: a large amount of oil here is transported to the East, to China, to provide reliable supply for users with increasing energy demand, or to the southeast, across Afghanistan and Pakistan; To the southwest, across Iran, which is the most economically significant channel; Or to the northwest, to Russia, where Russia has control over the European gas pipeline.. This ensures control of all final destinations. The Baltic pipeline system (BPS) is a Russian transportation system operated by Transnet, an oil pipeline company. BPS transports oil from tiaman Pechora region, West Siberia region and Urals Volga River region to primorsk oil terminal in the east of Gulf of Finland. It consists of a variety of facilities that operate in a unified way to transport petroleum procts from one place to another

the control of oil and gas routes: a review of geopolitical disputes. The Georgia pipeline to the West has not been damaged, but it remains vulnerable. It's not just a fight between Russia and Georgia. Source: economist, August 2008., The route of the pipeline was formulated in 2008. It is an oil pipeline extending to the West with very poor export conditions. On August 5, 2008, a pumping station on the Baku Tbilisi Ceyhan (BTC) pipeline, 1100 miles (1760 km) east of Turkey, was set on fire. Turkey's Kurdish separatists claimed responsibility. The pipeline delivers 850000 barrels of crude oil from the Caspian Sea to the western market every day. The closure of the pipeline has led to the once falling oil price rising again. BP has invested $44 billion in the BTC pipeline and still controls the pipeline. BP bravely faces everything and thinks that the closure of the pipeline is only temporary. But two days later, war broke out between Georgia and Russia, and the pumping station was ablaze for several days

"the fourth Corridor project will rece Europe's dependence on Russian natural gas and transport natural gas from the Caspian Sea to Europe."

Another BP pipeline, Baku supsa, once transported crude oil to the Black Sea coast of Georgia (now blocked by Russian warships), which has been reopened but forced to close. On August 12, 2008, even though the war was over, BP stopped delivering natural gas to Baku Erzurum gas pipeline. The only pipeline from Azerjan, which has recently been running at full capacity, passes through Russia to the port of novorossisk. For the past 10 years, Georgia has been a reliable country with access to a number of new pipelines, safely and effectively controlled by several Western oil companies, which can pass through Russia and Iran. In fact, in the past few weeks, the pipeline has become the object of ridicule, but it is not over. Georgia points out that its energy structure has survived the war: its pipelines have not been blown up. Russia is willing to maintain good relations with Azerjan and Turkey. It is cautious that this is not an oil war. However, the crisis - including the crisis dispute between Armenian and Azerjani over Armenian - has been growing. The South Caucasus region is considered as the replacement point of the so-called "fourth corridor" project, which is an important strategic location that Western strategists dream of ending Europe's dependence on Russian natural gas and transporting natural gas from the Caspian Sea to the European market. In this "blueprint", the highlight is the Nabucco pipeline, which is designed to ship natural gas from the Caspian Sea to Europe in 2013. This project is in trouble because it is not supported by Europe. The competitor Russia's plan is called "fourth stream". In fact, in Turkmenistan, There are no large western energy companies operating, and one of the foreign policy legislative proposals signed by then Russian President Dmitry Medvedev has been submitted to Azerjan and Turkmenistan, where leaders are required to sell gas to Russia

pipeline operation. When laying pipelines, the construction projects not only include the work of laying pipelines by the government, but also the construction of pumping stations and compression stations, which also include the installation of many field equipment, which can be operated remotely. The field device is instrumented and consists of data acquisition unit and communication system. Field instruments include flow, pressure, thermometer and transmitter, and also need some equipment to measure relevant data. These instruments are installed in some special places along the pipeline, such as transmission station, pump station (fluid pipeline) or compressor station (gas pipeline), and control valve station. Because the information measured by these field instruments is collected in a regional remote control terminal unit (RTU), where the field data is transmitted to the central control area in real time by communication system. These communication systems can be satellite channel, microwave communication or portable telephone. The central control room sends out instructions to remotely control and operate the pipeline. In this control center, all data related to field survey are transmitted to a central database. These data are received from multiple RTU receivers along the pipeline. It is common to see RTUs installed at each workstation along the pipeline

the data acquisition and monitoring control system (SCADA) in the main control room receives all field information and transmits it to the pipeline operator through a set of screen or SCADA man-machine interface, which can display the operation status of the pipeline. The operator can remotely control the hydrodynamic conditions of the pipeline and send operation instructions to the field through SCADA (open or close the valve, open or close the compressor or pump, change the set point, etc.). In order to optimize and ensure the operation of these supervisors, some pipeline companies are using a software tool called "advanced pipeline applications", which is installed on the top of SCADA and can add leak detection, leak location, measurement tracking, pig tracking, component tracking, calibration modeling, pre modeling, and other functions Operator training and other functions

8. 1? Japanese brands, including Sony, Toshiba, Panasonic, Hitachi, NEC, Sanyo, meishangmei, etc< br />2? Korean brands, including Samsung, LG, Costa, Hyundai, Taiyi, etc< br />3? Taiwan brands in China, including Acer Elite, BTC, ASUS, etc< br />4? Singapore brand, including innovation, maintenance, etc; Other brands such as Philips are hard to list
in general, the Japanese brand optical drive is relatively stable, with flat performance curve. After long-term use, the performance decline is not obvious, and the noise is small. However, the disk reading ability is average, the panel design is conservative, and there is often no play key. The style is solemn but not very beautiful. Generally speaking, Korean brand optical drives have better disk reading ability and better panel design, but after long-term use, their performance declines significantly and the noise is also large. The CD-ROM reading ability of Taiwan brand in China is slightly worse than that of South Korea. The panel is very distinctive and the performance is more stable than that of South Korea brand, but the noise is still a little bit loud. The CD-ROM reading ability of Singapore brand is a little better than that of Japanese brand. The panel design is very beautiful and the buttons feel comfortable. Some innovative procts also have intelligent remote control, but the performance is not as stable as that of Japanese brand, and the noise is a little bit higher. Note that the above views only represent the general situation, and the specific situation may vary with the origin, assembly level, a specific brand and other factors.

9.

1、 The layout design of manuscripts:

1. Main components of manuscripts:

1. Main Title: the name of manuscripts, such as healthy tomorrow

(2) header: a picture closely following the main title is organically combined with the main title

③ article: it is the main part of the hand copied newspaper

④ Title: it refers to the title of each article

⑤ tail flower (or flower arrangement), which is generally used at the end or in the middle of the article

(6) lace decoration: used in the blank space between articles

(7) shading decoration: shading decoration for articles or topics
2. How to typeset:

1. Leave four sides free and draw lines gently with a pencil

(2) arrange the position of the topic, which can be represented by several boxes

③ arrange the position of each article, which can be represented by a larger box, and draw lines gently with a pencil in the box, either horizontally or vertically

(4) draw the position of the title with small squares

(5) the small box indicates the position of the tail flower (flower arrangement)

The title should be decorated

2. Manuscripts are completed
1. Articles are transcribed

(1) the font should be neat and beautiful, and there should be no typos

If more than two people together, the font should be unified

(3) the beginning and end of the word should be neat

2. Title writing

The title should be eye-catching

2. Write in art font

3. Decorate the title

(1) it can be decorated directly on the title

② it can also be decorated beside the text

4. The header should be eye-catching and not dazzling

5. The drawing of tail flower should be small and exquisite, and the starting point should not be eye-catching

6. Decoration of shading

(1) it can be done well in typesetting, or it can be decorated in writing

② light color can be used to brush the bottom or sketch the scenery

Finally, wipe the newspaper surface clean

extension materials:

the decoration and beautification of hand copied newspaper: mainly using color, drawing and other artistic means to make up for the monotony of the text and give people vivid, beautiful and harmonious beauty and enlightenment. The contents include newspaper header, flower inscription, illustration, lace, tail flower and color application

1. Header: it is the sign of hand copied newspaper, which is composed of pattern or picture and journal name. The text is composed of header name, date, etc

2. Flower inscription: it is the decoration of the title or switch of an article. The common ones are shading and suggestive pictures or patterns

Illustration: according to the content of the article, you can draw a picture that can explain a plot, which is closely related to the content of the article; You can also use patterns that have nothing to do with the content of the article, such as flowers and birds, landscapes, etc., which are purely for beautification

Lace: generally, it should not be too much, too big or too thick, otherwise, it will make a fuss. Lace can beautify the layout, can separate the article, easy to read

Tail flower is a picture or pattern decorated at the back of the article. For example, after ing an article, there is still a blank. You can draw a flower, which can not only enrich the layout, but also increase the aesthetic feeling

6, color: generally concise, bright, elegant, not too much rendering, messy. Generally speaking, the tone of the text should be simple and steady; Title and lace, illustrations, etc., can be used more bright colors. Only in this way can the shade be appropriate and the effect be enhanced

10. This is actually a problem of collective mitigation, i.e. A-B
#include < stdio.h > < br/>#include < string.h> < br/>#include <
void squeeze (char*s1, char*s2)
{
int n=strlen(s1);
br/> char *q;< br/> char *tmp=(char*)malloc(n+1);< br/> if(! tmp) exit(0);< br/>
strcpy(tmp,s1); /* The preservation of the transitional space */

/* corresponding to the recurrence of existing letters in tmp in S2; 0 replaces*/
q=s2;
br/> while(*q)


> for (i=0; i< n; i++ 92; 0 ' < br/ > / q+; / * The following words are copied */
}
/* filter0字符*/
for (k=0.i=0; i< n; i++)
< if(tmp[i]=&# 39; &# 92; 0') 0& #39;) s1[k+]=tmp[i];< br/> s1[k]=' &# 92; 0 ' /* Completion mark*/
free(tmp);
br/>}

int main()
{
char strl[20]=" ABKCHACBXAYBTC " < br/> squeeze(str1, " AC " ;< br/> printf("% s & #92; n ", str1);< br/> return 1;< br/>}