Is the application of blockchain an economic problem

1. 1. What is blockchain? In a word
A: blockchain is an encrypted database chain, that is, the transaction data in multiple timestamps / events are encrypted and linked together, and the data can not be tampered with or shared
2. Performance and logic:
A. external operation forms: bank deposit and withdrawal, remittance, account in and out, shopping, currency issuance, capital transaction, etc
B. internal logic processing (software program): after human operation, the data will be encrypted first and then stored in the database. After the program, the data will be divided into regions, such as the data in the event and time stamp will be classified and put together into a region. Multiple events and data in timestamps are associated to form a blockchain. The encrypted data can be shared, but not tampered with
C. forms of sharing: querying personal information, auditing, etc. Query permission / sharing permission: different permissions can query different data. For example, the bank can query the information of all people, and the indivial can only query the indivial
3. Most of the examples are different, but the logic processing ideas are the same, but the implementation methods and operations are different
4. Blockchain: it has the characteristics of encrypted data, tamperable data and shared data
5. Blockchain Technology: the technology of encrypting, partitioning and sharing data with editing programs
there are suggestions for guidance
application fields: finance, it, commodity sales, online shopping, etc.

2. Principle of blockchain: decentralized distributed accounting system
the core of blockchain technology is that all participating nodes jointly maintain the transaction and database, which makes the transaction based on the principle of cryptography rather than trust, so that any agreed parties can directly carry out payment transactions without the participation of a third party< br />?
technically, a block is a data structure for recording transactions, reflecting the capital flow of a transaction. In the system, the blocks of the transactions that have been reached are connected together to form a main chain, and all the nodes participating in the calculation record the main chain or part of the main chain. A block contains the following three parts: transaction information, hash formed by the previous block, and random number. Transaction information is the task data carried by the block, including the private keys of both parties, the number of transactions, the digital signature of electronic currency, etc; The hash hash formed by the previous block is used to connect the blocks and realize the sequence of past transactions; Random number is the core of the transaction. All miners compete to calculate the answer of the random number. The node that gets the answer the fastest generates a new block and broadcasts it to all nodes for updating, so as to complete a transaction

1.1 what is a blockchain

blockchain is a technical solution to collectively maintain a reliable database through centralization and de trust in the past. This technical solution mainly allows any number of nodes in the participating system to generate a series of data blocks by using cryptographic methods. Each data block contains all the information exchange data of the system in a certain period of time, and generates a data fingerprint to verify the validity of its information and link to the next database block< br />?
generally speaking, blockchain technology refers to a way for the whole people to participate in bookkeeping. There is a database behind all the systems, that is, a big ledger. So it's very important who keeps this account book. At present, whose system is responsible for bookkeeping, the account book of each bank is the account book of each bank, and the account book of each bank is the account book of Ali. But now in the blockchain system, everyone in the system can have the opportunity to participate in bookkeeping. If there are new transaction data changes in a certain period of time, everyone in the system can make bookkeeping. The system will judge the fastest and best bookkeeper in this period, write the recorded content into the account book, and send the content of the account book to all other people in the system for backup. In this way, everyone in the system has a complete account book. As a result, the data becomes very secure. Tamperers need to modify more than half of the system node data at the same time to truly tamper with the data. The cost of such tampering is so high that it is almost impossible. For example, bitcoin has been running for more than seven years, and countless hackers around the world have tried to attack bitcoin, but so far there have been no trading errors. It can be considered that bitcoin blockchain has been proved to be a safe and reliable system< br />?

1.2 why is there blockchain innovation

human beings need to communicate in the process of activities, and communication is based on information. In the past, information circulation was not convenient enough to meet the information needs of market participants, so the intermediary and center were born. This centralized system has the problems of high cost, low efficiency, scattered value, "information island" and unsafe data storage. However, e to technical and environmental factors, this system still continues to operate for many years until the emergence of the Internet. The starting point of the first generation Internet is TCP / IP protocol, which is to implement the open code of peer-to-peer transmission of information in a unified format of all nodes on the network, and to program, protocol and execute the basic values of freedom and equality needed by the global unified market. Internet eliminates the middle chain of low value and high cost, and realizes the low cost and high efficiency of global information transmission by decentralization< br />?< However, the first generation Internet did not solve the credit problem of information. The activities that can be decentralized on the Internet must be those that do not need credit endorsement, and those that need credit guarantee must be those that are centralized and participated by third-party intermediaries. As a result, Internet technology, which is unable to establish global credit, has encountered great obstacles in its progress - people can not participate in any value exchange activities on the Internet in a decentralized way. In order to realize value exchange, people still need the third-party intermediary (such as bank, clearing, exchange) based on credit. There are still some problems in the global centralized credit system, such as high operating cost, low efficiency and vulnerability to attack. For example, the legal currencies of different countries have different credit values and different clearing systems, which increase the cost of Global trade< br />?
therefore, what the second generation Internet must break through is: how to decentralize the establishment of global credit? So that the value transfer is also low-cost and efficient. We need to create a kind of technology in the Internet, which can also engage in value exchange activities on the premise that people can't trust each other, so as to achieve real decentralization and go to the third-party intermediary, and realize the transformation from information internet to value Internet

1.3 application of blockchain

Bubi blockchain has been applied to equity, supply chain, points and other fields, and is carrying out experiments and application tests with exchanges and banks
as an integral application on Bubi blockchain, Shubei Hebao has been launched recently, which is a good demonstration for the landing application of blockchain technology in various instries

1.4 why the financial instry needs blockchain

trust is the foundation of the financial instry. In order to maintain trust, the development of the financial instry has spawned a large number of high-cost, low-efficiency, single point of failure intermediaries, including trusteeship, third-party payment, notaries, banks, exchanges and so on. Blockchain technology uses new encryption authentication technology and decentralized consensus mechanism to maintain a complete, distributed and tamperable account book, so that participants can ensure the security of funds and information through a unified account book system without mutual recognition and trust. This is of great significance to finance. Therefore, global financial giants are exploring blockchain applications one after another. On the one hand, this is to prevent the risk of being subverted; on the other hand, it is also "for our own use" to improve efficiency and rece costs, so as to consolidate, optimize and expand the existing power< br />?
first, blockchain can rece trust risk. Blockchain technology has the characteristics of open source and transparency. The participants of the system can know the operation rules of the system, verify the authenticity and integrity of the account book content and account book construction history, and ensure that the transaction history is reliable and has not been tampered with, which is equivalent to improving the accountability of the system and recing the trust risk of the system. For example, blockchain can avoid the current Internet Financial P2P running, fraud and other events< br />?
secondly, blockchain can improve the efficiency of payment, transaction and settlement. On the blockchain, the process of transaction confirmation is the process of clearing, settlement and auditing. Blockchain uses distributed accounting, all transactions are displayed in real time on a spreadsheet similar to global sharing, real-time clearing, and efficiency is greatly improved. For example, the U.S. securities settlement system is t + 3, but the blockchain can improve the efficiency to the minute level, which can rece the settlement risk by 99%, thus effectively recing the cost of capital and systemic risk< br />?
thirdly, blockchain can rece operating costs. Financial business systems and back office work are often faced with long processes and multiple links. Nowadays, no matter visa, master or all of them operate in a centralized way, money transfer has to go through a third party, which makes the cost of cross-border transaction, currency exchange rate, internal accounting and time cost too high, and brings risks to capital. Blockchain can simplify and automate the lengthy financial service process, rece the interaction between foreground and background, and save a lot of human and material resources, which is of great significance to optimize the financial business process and improve the financial competitiveness. The Bank of Spain believes that by 2022, blockchain technology will help the financial instry rece its bookkeeping costs by $20 billion< br />?
fourthly, blockchain can effectively prevent failures and attacks. The traditional financial model takes the exchange or bank as the center. Once the center fails or is attacked, the whole network may be paralyzed and the transaction will be suspended. The blockchain is supported by many distributed nodes and computer servers on the point-to-point network. The problems of any part will not affect the overall operation, and each node keeps a of the blockchain data. Therefore, the built-in business continuity of blockchain has high reliability and fault tolerance< br />?
fifthly, blockchain can improve the level of automation. Since all files or assets can be represented in the form of codes or ledgers, smart contracts and automatic transactions can be realized on the blockchain by setting the data processing program on the blockchain. For example, a smart contract can write a set of financial terms into the agreement to ensure the automatic execution and default payment of the contract< br />?
sixth, blockchain can meet regulatory and audit requirements. The records stored on the blockchain are transparent, traceable and unchangeable. Any record, once written to the blockchain, is permanent and cannot be tampered with. Any transaction between two parties can be tracked and inquired< br />?
in addition to the above positive effects on existing systems and business models, blockchain can also drive the birth of new business models. On the one hand, the characteristics of blockchain technology enable it to achieve some business models that are difficult to achieve in the centralized mode. On the other hand, blockchain greatly encourages the innovation and cooperation of the whole society through the opening and cooperation of source code. Of course, there will be a lot of problems and challenges in the application of blockchain in finance. This paper also thinks about the specific application

the working principle of blockchain technology is not difficult to understand. If we focus on the application research of specific blockchain technology, we can find that the working principle of this blockchain technology is ubiquitous.

3. Blockchain technology is a new development of Internet technology and modern information technology. It plays an important role in China's real economy and supply side structural reform. Promote the R & D and application of blockchain technology, deeply integrate with the real economy, and create an advanced manufacturing instry. It can realize the high-quality development of China's economy and is an important driving force for the construction of a modern economic system.

4. Blockchain solves the problem of trust, which is the root of all problems
wikilink is a complete intelligent contract platform supporting Turing. Wikilink adopts the consensus mechanism of dpos, with a total of 11 voting nodes, generating a new block every 10 seconds. Through the smart contract wikilink, we can realize a wealth of application scenarios, such as asset issuance, guessing applications, right traceability, mutual insurance, decentralized exchanges, cross-border settlement, etc
but the most important thing in these scenarios is trust, which is to be open and transparent.

5.

The development of blockchain has been booming. What are the application areas of blockchain

at present, the most extensive and successful application of blockchain technology is digital currency represented by bitcoin. In recent years, digital currency has developed rapidly. Due to the characteristics of decentralized credit and frequent transactions, it has high transaction value and can maintain a relatively stable price by developing hedging financial derivatives as quasi super sovereign currency

three , blockchain data is completely open and transparent. If anti anonymous identification technology can be developed in the future and a user's information can be seen through password cracking, the positioning and identification of some key targets may also pose a threat to data security and personal privacy

At present, supervision is still on the way. Decentralization means that the main body is not clear, which also brings great difficulty to supervision; In particular, regulators under the blockchain technology will face the "huge amount" of data, and it is difficult to achieve accurate supervision by standardizing the transparency of information. In addition, the vacancy and lag of regulatory legal system make the use of blockchain lack of necessary institutional norms and legal protection, and increase the market risk

obviously, blockchain technology is not a "safe box" to ensure the absolute security of financial instry and other economic activities, nor a "panacea" to serve all economic activities . Both the enterprises involved in the research and development and application of blockchain technology and the investors involved in the investment of instrial projects in blockchain should maintain a cautious and rational attitude

7.

Selenium is a chemical element and a nonmetal

There are two forms of selenium in nature: inorganic selenium and plant active selenium. Inorganic selenium generally refers to sodium selenite and sodium selenite, which are obtained from the by-procts of metal deposits; The latter is formed by the combination of selenium and amino acids through biotransformation, and generally exists in the form of selenomethionine

There are four main functions of selenium:

1. Scientific confirmation: it is precisely because of & quot; Selenium & quot; It can prevent organ aging and pathological changes, delay aging, enhance immunity, resist diseases, resist toxic heavy metals, rece the side effects of radiotherapy and chemotherapy, and prevent cancer

Second, to prevent diabetes. Selenium is an active component of glutathione peroxidase (GSH PX), which can prevent pancreatic islets β Cell oxidative damage, make its function normal, promote sugar metabolism, rece blood sugar and urine sugar, improve the symptoms of diabetic patients

Third, detoxification and detoxification. Selenium has a strong binding force with metal and can resist the toxicity of cadmium to kidney, gonad and central nervous system. Selenium combines with mercury, lead, tin, thallium and other heavy metals in the body to form a metalloselenoprotein complex and detoxify

Prevention and treatment of liver disease. After 16 years of epidemiological investigation of liver cancer in China, Chinese medical expert Yu Shuyu found that the selenium content in the blood of residents with high incidence of liver cancer is lower than that in low incidence area of liver cancer. The incidence rate of liver cancer is negatively correlated with blood selenium level. She added selenium to 130 thousand residents in Qidong County of Jiangsu Province, and confirmed that selenium supplementation reced the incidence rate of liver cancer by 35%, and the incidence rate of liver cancer was 50%. p>

extended data :

don't blindly supplement selenium, the key to a balanced diet

in recent years, many people have joined the "army of selenium supplement", believing that selenium supplement is helpful to "cancer prevention". However, this practice is not worth encouraging, because selenium, like other trace elements, should adhere to the principle of appropriate amount, not more is better, and it is not suitable for everyone

selenium has such a strong anti-cancer effect. The results of the study have not yet been reached. Some studies have shown that selenium can rece the incidence rate of some cancers, but some studies have negated this conclusion. Therefore, the scientific research evidence of selenium as an anticancer agent is still very limited

The range between the beneficial and toxic amounts of selenium is the narrowest among all trace elements, so the most technical content is required for selenium supplement, and it will be excessive if you are not careful. Under normal circumstances, the recommended daily selenium intake is 50 ~ 200 μ G

In addition, excessive supplement of selenium will hinder the absorption of manganese in human body, and lack of manganese will cause a series of health problems. Therefore, we can not blindly supplement selenium. Some researchers warn that blind selenium supplement may increase the risk of some diseases. If you want to supplement selenium, you should go to a regular hospital to determine the level of trace elements in the body, and supplement selenium under the guidance of doctors to avoid poisoning

human body can not synthesize selenium itself, and food is the main source of selenium. A healthy person who is not partial to or picky about food can meet the body's demand for selenium through a balanced diet without additional supplement

all kinds of selenium rich foods on the market, such as selenium rich rice, selenium rich vegetables, etc., can be eaten occasionally, but it is not necessary to buy them often. If you must eat selenium rich food, it's best to choose the one marked with selenium concentration, calculate the body's needs and then buy it

The content of selenium in natural food was as follows: animal viscera, seafood, fish, eggs, meat, grain, milk, onion, garlic, vegetables and fruits. Sesame and garlic also contain a lot of selenium. The selenium content of the same crop in different areas is very different, and there is an order of magnitude difference of 1000 times or even 10000 times