Three frameworks for blockchain front end

1. Government management
some countries have shown great interest in the blockchain technology of decentralized data management framework to store public data. For example, essentia is developing an e-government project with the Central Union of agricultural procers and forest owners in Finland, The project will apply blockchain technology to enable urban and rural residents in Finland to query various records, fully meet the needs of residents and employers, and improve the employment rate. In addition, the use of this technology can also improve the efficiency of government operation, so that residents can easily query ecation, public records, voting and other information
waste recycling
for example, an intelligent waste management system in China adopts the RFID technology of waltonchain company. Using this blockchain application of waltonchain, it can effectively monitor the waste level, so as to improve the management and operation efficiency and resource optimization
identity recognition
chug, a Swiss city known as "encryption Valley", has developed an identity authentication system with its partner uport by using blockchain technology, through which citizens can participate in online voting and proof of residence
border control
essentia has been in contact with the Dutch government, hoping to use its blockchain technology to establish a set of border inspection system for the Dutch government to check passengers between Amsterdam and London. At present, passengers of Eurostar high-speed rail between the two countries need to undergo border control checks at multiple locations. Essentia is working on a blockchain based solution that will securely store passenger data so that inspection records from the Netherlands can also be reviewed by UK Border agencies. Blockchain technology will ensure that the data has not been tampered with and is verifiable and accurate
health care
as we all know, medical records are very scattered and prone to errors. Inconsistent data processing process will make hospitals and clinics often forced to deal with some incorrect or incomplete patient records. For example, Medrec, a blockchain electronic medical record system developed by MIT, uses blockchain technology to promote data sharing. At the same time, it can also provide authentication and confidentiality services
enterprise management
as enterprise customers of Microsoft azure applications, they can make use of blockchain as a service (baas), which will enable enterprises to access smart contracts and blockchain applications in a secure hosting environment. According to media reports, Google is also developing a proprietary blockchain project to support its cloud based business. And alpha, Google's parent company, is developing a distributed accounting project that third parties will be able to use to store data related to Google's cloud services
medical data
medical centers that digitize patient records do not store data among multiple devices. They usually store data on centralized servers, which has become the main target of hackers. The wannacry attack on NHS hospital in the UK proves this. But in addition, even if the security risk is ignored, there is still the problem of fragmentation. At present, there are more than 50 different electronic medical record systems (EHR) operating in hospitals in different cities around the world, and there are usually dozens of different medical application systems in the same city. These independent systems can't perform interoperation, and the data of patients in each hospital can only be distributed in different data storage centers
in the case of patients' life and death, the lack of reliable medical data contrast and slow operation efficiency will be fatal. Essentia's application framework solves all these problems by using blockchain based system, which will store all clinical data of patients, and can access these data immediately regardless of geographical boundaries. In this system, the patient's medical record privacy can also be protected, and only the authorized medical personnel can access it in a specific period of time
Music Proction
one of the main advantages of blockchain technology is that it eliminates unnecessary middlemen or middlemen. The music instry is a typical example. In this instry, if artists are inefficient, they will get very low remuneration. At this time, a number of blockchain based projects have emerged to seek a fairer trading and business environment for music creators, such as artbit, a former gunshot rose drummer Matt Soren as director
carbon compensation
as a highly instrialized country, China's environmental change is huge. In March 2017, IBM and energy blockchain labs jointly launched the hyperledger fabric blockchain project to discover China's carbon assets, which not only creates a measurable and auditable system for tracking carbon emissions, but also provides a tradable market for companies seeking to offset energy consumption and stimulate green instrial practice
supply chain management
supply chain management is considered to be one of the better cases of applying blockchain, because it is very suitable for the express delivery of such goods from delivery to receipt or the whole process from manufacturer to store. IBM and Wal Mart have jointly launched a blockchain food safety alliance in China. The project is also jointly operated with Jingdong company, aiming to improve food delivery tracking and safety assurance, so as to make it easier to trace food safety issues
facts have proved that China is a mature experimental base for blockchain projects, and it is also the location of the world's first blockchain for agricultural procts (5.180, - 0.25, - 4.60%). Louis Dreyfus Co, a world-famous food trader, has established a blockchain technology project in cooperation with Dutch and French banks. Using this project technology, the transaction settlement is faster than traditional methods in the process of selling soybeans to China
diamond instry
De Beers Group, the world's most famous diamond company, has its own blockchain company and has started operation. Its purpose is to "establish a digital record for every diamond registered on the platform". Considering the origin of diamonds, the ethical standards of origin, and the risk of diamond quality, blockchain technology is a good choice, because every record of it is indelible, and it will ensure that the electronic data of each diamond is as permanent as itself
real estate transactions
currently, Ukraine is the first country to use blockchain technology to promote property transactions. Michael Arlington, the founder of techcrunch, a famous technology website and cryptocurrency player, remotely purchased and resold a real estate in Kiev through the smart contract of Ethereum blockchain. This transaction was completed by propy, a start-up company specializing in blockchain real estate transactions
fisheries
blockchain technology is now being used to support the development of sustainable fisheries. Illegal fishing is a common problem in this instry. The distributed ledger technology of blockchain provides a proof of the capture source, processing and sale mode. This "net to table" supply chain allows inspectors to determine whether the fish caught came from a human rights violation area or from a country affected by economic sanctions
art paintings
similar to diamond trading, the art instry relies on the provenance and authenticity of art works. Although the blockchain cannot identify whether a painting is an original or a fake, it can be used to prove the identity of the previous owner of the painting. In addition, blockchain technology is now also used as a means to obtain works of art. It can make tangible goods easily traded and exchanged anywhere in the world without physical transfer from a secure storage place
public facilities
in Freemantle, Australia, a project dedicated to distributed energy and water system management is using blockchain technology, and solar panels (3.340, - 0.06, - 1.76%) are being used in sunny areas to obtain electricity, which is then used to heat water and provide electricity, All these energy conversion and use information will be recorded in the blockchain data
in Chile, the National Energy Commission has started to use the blockchain technology as the verification of the country's energy use data, and some sensitive data will be stored in the blockchain. The application of this technology can be regarded as a means for the modernization and safe operation of power infrastructure in this South American country
LGBT rights
blockchain can help build a "pink economy" and help LGBT communities fight for their own rights without revealing people's identities. This is an extremely important issue, because crimes of discrimination against homosexual groups often occur, especially in countries notorious for human rights violations, Homosexuality is illegal, or at least not allowed
catastrophe bonds
catastrophe bonds may be the only hope for victims of earthquakes, tsunamis and other natural disasters. Blockchain allows fast and transparent reconciliation between the parties, and can ensure that the system can continue to operate normally even under unmanned operation. Now, blockchain has been successfully used in the settlement mechanism of catastrophe bonds
tourism
local institutions in Hawaii are studying how to use blockchain technology to improve the economy, such as opening bitcoin and other monetary payment means to facilitate tourists' transaction of local goods and services. In this way, the Hawaiian government hopes to attract tourists, especially those from Asia, to spend more money in the local area and improve the economic development of Hawaii
homeland security
in 2016, the US Department of Homeland Security (DHS) announced a project that will use blockchain technology as a means of secure storage and capture of data transmission. DHS uses Factom's blockchain technology to encrypt and store data captured by security cameras and other sensors. The application of this blockchain technology will greatly rece the risk of data leakage. At present, the project is still in progress
maritime transportation
it is self-evident that blockchain is used to record ship transportation data. At present, some local shipping projects have adopted distributed ledger technology. In the maritime logistics instry, blockchain technology can make the inevitable cumbersome management proceres in international trade more transparent and orderly. Maersk, one of the world's largest shippers, is a pioneer in the use of blockchain. Today, Yixing international shipping company Zim has also made follow-up use of blockchain technology.

2. Introction to seven core technologies of blockchain operation on January 15, 2018
1. Blockchain links
as the name suggests, blockchain is a chain composed of blocks. Each block is divided into block head and block body (including transaction data). The block head includes the prevhash value (also known as hash value) of the previous block used to realize the block link and the random number (nonce) used to calculate the mining difficulty. The hash value of the previous block is actually the hash value of the head of the previous block, and the random number calculation rule determines which miner can obtain the right to record the block
2. Consensus mechanism
blockchain is accompanied by the birth of bitcoin, which is the basic technology architecture of bitcoin. Blockchain can be understood as an Internet-based decentralized accounting system. A decentralized digital currency system like bitcoin requires the consistency of accounting of honest nodes without a central node, which needs blockchain to complete. Therefore, the core of blockchain technology is a consensus mechanism to reach a consensus on the legitimacy of transactions between indivials without mutual trust without central control
there are four main types of consensus mechanisms in blockchain: pow, POS, dpos and distributed consistency algorithm
3. Unlocking script
script is an important technology to realize automatic verification and contract execution on blockchain. Every output of every transaction does not point to an address in the strict sense, but to a script. A script is like a set of rules that constrain how the receiver can spend the asset locked on the output
the validation of transactions also depends on scripts. At present, it depends on two kinds of scripts: Lock script and unlock script. Locking script is a condition added to the output transaction, which is realized by a script language and located in the output of the transaction. The unlocking script corresponds to the locking script. Only when the conditions required by the locking script are met can the assets corresponding to the script be spent, which is located in the input of the transaction. Many flexible conditions can be expressed by script language. Interpretation script is similar to the "virtual machine" in our programming field, which runs in every node of the blockchain network in a distributed way
4. Transaction rules
blockchain transaction is not only the basic unit of a block, but also the actual effective content recorded by the blockchain. A blockchain transaction can be a transfer, or the deployment of smart contracts and other transactions
as far as bitcoin is concerned, a transaction refers to a single payment transfer. The transaction rules are as follows:
1) the input and output of the transaction cannot be empty
2) for each input of a transaction, if its corresponding utxo output can be found in the current transaction pool, the transaction will be rejected. Because the current transaction pool is the transaction not recorded in the blockchain, and each input of the transaction should come from the confirmed utxo. If it is found in the current trading pool, it is Shuanghua trading
3) for each input in a transaction, the corresponding output must be utxo
4) each input unlocking script must verify the compliance of the transaction together with the corresponding output locking script
5. Transaction priority
the priority of blockchain transaction is determined by the blockchain protocol rules. For bitcoin, the priority of a transaction to be included in a block is determined by the time when the transaction is broadcast to the network and the amount of the transaction. With the increase of transaction broadcast time on the network and the increase of transaction chain age, the priority of transaction will be improved and eventually be included by the block. For Ethereum, the priority of the transaction is also related to the transaction fee that the publisher is willing to pay. The higher the transaction fee that the publisher is willing to pay, the higher the priority that the transaction is included in the block
6. Merkle proof
the original application of Merkle proof is bitcoin, which was described and created by Satoshi Nakamoto in 2009. Bitcoin blockchain uses Merkle proof to store transactions in each block. So that the transaction can not be tampered with, but also easy to verify whether the transaction is included in a specific block
7. RLP
RLP (recursive length prefix) is one of the main encoding methods of object serialization in Ethereum. Its purpose is to encode the sequence of arbitrary nested binary data.

3. Consensus, circulation and creation happen to be the core values of Wen ecology.

4. This is determined by your programming level. At present, the level of domestic programmers is basically a pyramid structure, and most of them are middle-level programmers. From this point of view, it is basically impossible for most people to learn functional programming. One of the most important reasons for choosing go is that a middle-level programmer can write very good go code. The main reason is that go language is very simple, features are very few, and the official class library is very rich. Most programmers can easily start to develop it. Chain33 blockchain developer platform, a well-known domestic open source project, is completely completed by go. There are many mature blockchain technologies in China, such as micro three cloud, etc., which will not be repeated here.

5. Go language + blockchain training course:
from the characteristics of the language itself, go is a very efficient language, which highly supports concurrency. Go language itself pays more attention to distributed systems, and concurrency processing is relatively good, such as advertising and search, which are high concurrency servers
go language advantages:
excellent performance, can be directly compiled into machine code, does not rely on other libraries, go is extremely fast. Its performance is similar to Java or C + +
concurrency is supported at the language level, which is the biggest feature of go. It is born to support concurrency, and go is the concurrency supported in gene, which can make full use of multi-core and make it easy to use concurrency
the built-in runtime supports garbage collection, which is one of the features of dynamic language. Although GC is not perfect at present, it is enough to cope with most of the situations we can encounter, especially GC after go1.1
it's easy to learn. The authors of go language all have the gene of C, so go naturally has the gene of C. There are 25 go keywords, but the expressive ability is very strong. It almost supports most of the features you've seen in other languages: inheritance, overloading, object, etc
rich standard libraries, go has built a large number of libraries, especially the network library, which is also my favorite part< As like as two peas, br / > built-in powerful tools, Go language is built with many tools chain, the best should be gofmt tools, automatic formatting code, make team review become so simple, code format is exactly the same, it is very difficult to think differently.
cross platform compilation and fast compilation. Compared with the sluggish compilation speed of Java and C + +, the fast compilation time of go is a major efficiency advantage
disadvantages of go language:
package management: package management of go language is absolutely not perfect. By default, it has no way to make a specific version of the dependency library, nor can it create replicable builds. In contrast, python, node and Ruby all have better package management systems. However, with the right tools, the package management of go language can also perform well
lack of development framework: go language does not have a major framework, such as Ruby's rails framework, Python's Django framework or PHP's laravel. This is a heated discussion in the go language community, because many people think that we should not start with using frameworks. This is true in many cases, but if you just want to build a simple crud API, it's much easier to use Django / djrf, rails laravel, or Phoenix
exception handling: go language can help developers deal with compilation errors by simply returning errors (or call stack) through functions and expected calling codes. Although this method is effective, it is easy to lose the scope of the error, so it is difficult to provide meaningful error information to users. Error package can solve this problem by allowing us to add context and stack trace to return error
another problem is that we may forget to handle errors. Static analysis tools such as errcheck and megacheck can avoid these errors. Although these solutions are very effective, they may not be the right way.

6. Increase in proportion to the total volume of border trade; RMB is becoming the currency in circulation in the border areas of neighboring countries in Yunnan Province; RMB has become the main settlement currency of border trade in Yunnan Province; Yunnan is China. What do you say

7. GT has no erc20 token on Ethereum

8. In what area

9. Aggregation chain refers to the innovative introction of "alliance chain + cross chain + public chain" aggregation chain technology architecture on the basis of long-term accumulated alliance chain technology, so as to realize the efficient, safe and low-cost flow of data and assets, and then practice the historical mission of enabling distributed economy.