The significance of blockchain technology to economic constructi

1. A brief review of the origin of blockchain
blockchain is the underlying system of distributed ledger in bitcoin. Bitcoin ledgers are built in a distributed and spontaneous way. Anyone can generate new currency blocks by performing specific cryptographic calculations, so as to obtain a digital "currency" that can be used for transactions. Bitcoin's impact on the world monetary system can be said to be subversive, which is also an important reason why it has attracted a lot of people's strong attention since it came out. After that, there were dozens of similar electronic currencies such as
"lightcoin". The abstract extraction of distributed digital currency technology from bitcoin forms a "blockchain" technology, which can be used in more fields
the basic idea of blockchain is to establish a network-based public ledger (data block), each block contains the information of a network transaction. All the participating users in the network work together to keep accounts and check accounts. All the data are open and transparent, and can be used to verify the effectiveness of the information. In this way, the authenticity and non tamperability of information can be guaranteed at the technical level without the central server as the trust intermediary
the significance of blockchain lies in "decentralization", which can fundamentally solve the fraud and rent-seeking phenomenon in value exchange and transfer by building a more reliable network system. With the popularization of blockchain technology, the digital economy will be more authentic, and the economic society will become more fair and transparent
not only digital currency, but also blockchain technology is infiltrating into more innovative fields.
virtual digital currency such as bitcoin is just an application scenario of blockchain technology. Theoretically speaking, based on the characteristics of blockchain technology, human beings can create a very rich form of services and procts, such as finance, government, enterprises, etc There are a large number of scenarios suitable for blockchain technology in cross instry and other fields, with broad prospects. At present, many countries around the world have started the research of blockchain technology, and a series of instry organizations and alliances have been established. However, as blockchain technology is a brand-new technology, which subverts the traditional centralized mode, major institutions are still in the research stage, with only a small number of actual projects landing, and the great development of the instry has just begun
now, blockchain economy is on the eve of outbreak. The exploration of financial instry is ahead of others, while the application of other instries is developing rapidly. The obvious advantage of blockchain instry application is to optimize business process, rece operation cost and improve collaborative efficiency. This advantage has been graally reflected in financial services, Internet of things, public services, social welfare and supply chain management
as the backbone of emerging technologies, blockchain is not only used in the field of virtual currency, but also in other fields such as finance, medical care, intellectual property certification, etc. a large number of excellent enterprises have emerged in China to explore or enter the blockchain instry. According to the in-depth analysis report on business model innovation and investment opportunities of blockchain instry released by foresight Instry Research Institute, as of the end of 2016, there were 105 blockchain related enterprises in China, 80% of which were concentrated in eastern coastal cities, including Shanghai, Hangzhou and Taipei
from the perspective of global blockchain technology application development, as of April 2017, financial service companies accounted for 55.43% of the 267 blockchain venture capital companies; From the perspective of the Chinese market, 34 of the top 50 blockchain venture capital companies in 2016 are involved in financial services, mainly in cross-border payment, bill discounting and financial service platform<
analysis of the development trend of blockchain
the combination of blockchain and cloud computing is more and more close, and baas is expected to become a public trust infrastructure
cloud computing is the general trend. We believe that the combination of blockchain and cloud is also an inevitable trend. There are two modes for the combination of blockchain and cloud, one is blockchain in the cloud, the other is blockchain in the cloud. The latter, namely baas, blockchain-as-a-service, refers to that the cloud service providers directly provide blockchain as a service to users. In the future, more and more cloud service enterprises will integrate blockchain technology into the ecological environment of cloud computing. By providing baas function, they can effectively rece the deployment cost of enterprise application blockchain and rece the initial threshold of innovation and entrepreneurship
the security problem of blockchain has become increasingly prominent, and security protection needs the overall consideration of technology and management
blockchain system is almost perfect mathematically, with the advantages of openness and transparency, difficult to tamper, reliable encryption, anti DDoS attack, etc. However, from the engineering point of view, its security is still restricted by infrastructure, system design, operation management, privacy protection and technology update iteration. In the future, we need to consider the overall situation of technology and management, strengthen basic research and overall protection, so as to ensure the application security
the competition of blockchain is becoming increasingly fierce, and patent competition has become an important field of competition
with the increase of participants, the competition of blockchain will become more and more fierce, and the competition is all-round, including technology, mode, patent and other dimensions. We believe that in the future, enterprises will strengthen the layout of blockchain patents. Since 2014, the number of blockchain patent applications has grown explosively. Blockchain patents are mainly distributed in the United States in North America, the United Kingdom in Europe, China and South Korea in Asia, and this pattern will be maintained in the future. The patent gap between China and the United States is narrowing, and the number of applications in China in 2016 has surpassed that in the United States. It can be predicted that the patent competition of blockchain will become increasingly fierce in the future
with the acceleration of domestic policy process, the development of the instry ushers in a new opportunity
blockchain has attracted attention from all walks of life e to its core advantages of high performance, high security, high-speed access, efficient operation and so on. In the context of the rapid development of blockchain, China conforms to the needs of globalization, closely follows the international pace, and actively promotes the research, standardization and instrialization development of domestic blockchain related fields
trustworthiness is the core requirement of blockchain, and the importance of standards and specifications is becoming increasingly prominent
in the future value delivery network based on blockchain, we will completely use algorithms and software to build the trust foundation. However, we believe that this is far from enough, and we need the standard to increase the credibility of the blockchain. In the future, the standard of blockchain will standardize the technology and governance of blockchain from the perspective of users, business oriented, and from the dimensions of smart contract, consensus mechanism, private key security, and authority management, so as to enhance the credibility of blockchain and add weight to the trust of blockchain.

2. Many relationships between people are based on trust, such as friend relationship, cooperation relationship, transaction relationship, etc
take trading activities as an example. In the past, the two sides who did not trust each other usually chose an intermediary to guarantee a transaction. In the mobile Internet era, we chose Taobao shopping because Alipay provided us with an intermediate guarantee. We chose to drop dripping because it provided us with information matching.
however, these intermediaries are centralized and have their own interests. Sometimes they are not so reliable and trustworthy. Theoretically, Alipay's centralization of accounting has been artificially falsified. Part of the reason for Didi's troubles is that they only think from their own standpoint
what blockchain does is the machine of trust, which replaces the role of trust intermediary with code, ensures the fairness and justice of the whole system through consensus mechanism and distributed accounting, and provides a trust without trust
for example, in the future, people can abandon the intermediate platform and realize point-to-point docking and free trading through blockchain. Shopping does not need to go through an intermediary, and taking a taxi does not need to go through Didi. In this way, we can really achieve "no middleman to earn the price difference" and rece the cost.

3. 1、 Blockchain will play the role of "recing costs for the real economy". At present, the high cost and low profit of the real economy lead to the lack of capital support for the real economy. In the operating cost, the proportion of management cost and financial cost is not low. Blockchain technology can effectively help enterprises rece the cost of these two parts
secondly, blockchain will play a role of "improving the efficiency of instrial chain collaboration". Enhancing instrial collaboration is an important way to promote manufacturing in China to move towards the middle and high end. However, in many instries, the efficiency of instrial chain collaboration is still not high, especially in the field of international trade
thirdly, blockchain will play a role of "building an honest instrial environment". At present, the construction of China's social credit system is accelerating, but in some cases, the process of building trust among partners is still slow, it is difficult to obtain all kinds of credit information, and it is difficult for small, medium and micro enterprises to obtain credit loans from financial institutions. Through the "transaction on the chain", all aspects can more easily find out the accurate historical credit situation of the counterparties, and establish the cooperation mechanism faster; Banks can also give credit to enterprises more safely based on transaction records, and promote the solution of the problems of "difficult, expensive and slow financing" of small, medium and micro enterprises operating in good faith
in addition, blockchain can make use of smart contracts to avoid default and fraud to a large extent, and can also make efficient and convenient payment scenario applications in combination with blockchain asset wallet. As early as in the blockchain circle, there have been many innovation forums and Instry Summit aiming at the direction of blockchain enabling the real economy, and combining with the local economic instry to carry out landing optimization. For example, the world blockchain conference Macao station intends to make a deep integration with the local economic instry, and use and popularize the blockchain assets with the payment means of magic chain wallet.

4. To understand the principle of blockchain thoroughly, we must understand it systematically from its birth and development, so as to distinguish the principle of blockchain more clearly from multiple perspectives. Block chain technology refers to the technical solution of collective maintenance of a reliable database in a centralized way in the past. In this technical scheme, blocks are associated by cryptography. Each data block contains all the data information of the system in a certain period of time, and generates a digital signature to verify the validity of the information, and links to the next data block to form a main chain< br />
Block is a record in the blockchain, which contains and confirms the transactions to be processed< br />
mining refers to the formation of new blocks through calculation. It is a process in which the supporters of the transaction use their own computer hardware to do mathematical calculation for the network to confirm the transaction and improve the security. Take bitcoin as an example: the transaction supporter (miner) runs bitcoin software on the computer and constantly calculates the complex cryptography problems provided by the software to ensure the transaction. As a reward for their service, miners can get the Commission included in the transaction they confirm, as well as the newly created bitcoin< br />
Peer to peer network is a system that allows a single node to interact directly with other nodes, so that the whole system can operate like an organized collective. Take bitcoin: the network is built in such a way that each user is spreading the transactions of other users. And importantly, banks or other financial institutions are not required as third parties< br />
Hash is a classical technology in cryptography, which transforms the input of any length into the output of fixed length composed of letters and numbers through Hassi algorithm< br />
Digital signature is a mathematical mechanism that allows people to prove ownership< br />
Private key is a secret data block that proves that you have the right to consume e-money from a specific wallet. It is realized by digital signature< br />
Dual consumption refers to the user's illegal attempt to pay e-money to two different payees at the same time, which is one of the biggest risks of e-money< br />
?< br />
The origin of blockchain: an underlying technology supporting bitcoin

The concept of blockchain was first proposed in bitcoin: a peer-to-peer electronic cash system by Satoshi Nakamoto in late 2008. In this paper, block chain technology is the basic technology to build bitcoin data structure and transaction information encryption transmission, which realizes the mining and transaction of bitcoin. Nakamoto believes that: first, the mode of using third-party organizations to process information has the inherent weakness of lack of trust between points. In order to guard against their customers, businesses will ask customers for completely unnecessary information, but still can not avoid certain fraud; Second, the existence of intermediaries increases the transaction cost and limits the practical minimum transaction scale; Third, digital signature itself can solve the problem of e-money identity. If the third party support is needed to prevent double consumption, the system will lose value. Based on the above three existing problems, Nakamoto Cong has created bitcoin on the basis of blockchain technology< br />
On January 3, 2009, Nakamoto proced the first bitcoin block in the world, genesis block, and excavated 50 bitcoins< br />
On May 21, 2010, Florida programmers bought $25 worth of pizza coupons with 10000 bitcoin, which gave birth to the first fair exchange rate of bitcoin< br />
In July 2010, the first bitcoin platform was established, with a surge in new users and prices< br />
In February 2011, the price of bitcoin reached US $1 for the first time. Since then, exchange trading platforms with British pound, Brazilian real and Polish zloty have opened< br />
In 2012, ripple released that as a digital currency, it uses blockchain to transfer foreign exchange of various countries< br />
In 2013, bitcoin soared. The U.S. Treasury Department has issued the regulations on the personal management of virtual currency to clarify the definition of virtual currency for the first time< br />
In 2014, the mining machinery instry chain represented by China became more and more mature. In the same year, the U.S. it community realized the cross era innovation significance of blockchain in the digital field< br />
In 2015, the US Nasdaq Stock Exchange launched LINQ, a digital ledger technology based on blockchain, to record trading and issue stocks

the principle of blockchain can be understood clearly from each application case, and the application of blockchain principle is becoming more and more popular. Recently, Citigroup, Mitsubishi UFJ Financial Group, UBS and Deutsche Bank will also apply "blockchain" technology to build a fast, convenient and efficient blockchain Low cost trading system. In addition to the financial field, blockchain technology has also begun to be applied to the protection of intellectual property rights, notarization by lawyers, online games and other fields where there is a need for transparent information disclosure and permanent records.

5.

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