Alliance chain of Libra Ethereum

1.

Ethereum is a new and open blockchain platform, which allows anyone to build and use decentralized applications running through blockchain technology in the platform. Like bitcoin, Ethereum is neither controlled nor owned by anyone - it's an open source project created by many people around the world

Different from bitcoin protocol, Ethereum is very flexible and adaptable. It's very easy to create new applications on the Ethereum platform. Anyone can use the applications on the platform safely

Ethereum is a programmable blockchain. It does not give users a series of preset operations (such as bitcoin trading), but allows users to create complex operations according to their own wishes. In this way, it can be used as a platform for many types of decentralized blockchain applications, including but not limited to cryptocurrency

in a narrow sense, Ethereum refers to a series of protocols that define a decentralized application platform. The core of Ethereum is Ethereum virtual machine (EVM), which can encode any complex algorithm. In computer science terminology, Ethereum is "Turing complete.". Developers can use the existing JavaScript and python as the model of other friendly programming languages to create applications running on the Ethereum simulator

like other blockchains, Ethereum also has a peer-to-peer network protocol. Ethereum blockchain database is maintained and updated by many nodes connected to the network. Each network node runs the Ethereum simulator and executes the same instructions. Therefore, people sometimes call Ethereum "world computer"

this massive parallel operation throughout the Ethernet network is not to make the operation more efficient. In fact, this process makes computing on Ethereum slower and more expensive than on traditional computers. However, each Ethereum node runs Ethereum virtual machine in order to maintain the consistency of the whole blockchain. The consistency of decentralization makes Ethereum have high fault tolerance, zero downtime, and can keep the data stored on the blockchain unchanged and anti censorship

Ethereum platform has no characteristics and value. Like programming languages, it's up to entrepreneurs and developers to decide what to use. However, it is clear that some application types benefit more from the functions of Ethereum than others. Ethereum is especially suitable for those applications that automatically interact directly between points or promote group coordination activities across networks

for example, coordinate the application of point-to-point market, or the automation of complex financial contracts. Bitcoin enables indivials to exchange money without the help of financial institutions, banks or governments. The impact of Ethereum may be more profound

in theory, any complex financial activities or transactions can be automatically and reliably carried out on Ethereum with coding. In addition to financial applications, any application scenario with high requirements for trust, security and persistence, such as asset registration, voting, management and Internet of things, will be affected by Ethereum platform on a large scale

2. The digital currency

issued based on Ethereum public chain should be observed according to the price trend of the platform.

3. Many blockchain projects are developed on the basis of Ethereum's open source technology. Ethereum is a common public chain technology, and the deployment of applications on Ethereum has high requirements for developers. Developers need to consider many technical details and business processing logic, as well as security vulnerabilities such as smart contract overflow
the trust union credit alliance chain is located in the financial public chain, which is oriented to the high-frequency financial application scenarios in the field of credit and assets. It does not use eth, EOS, Neo and other general public chains, but uses the account structure of star network, adopts the lightweight intelligent contract layer, and the whole technical architecture is molarized according to "high aggregation and low coupling", This enables the trust union credit alliance chain to adapt to the requirements of rapid development, rapid implementation and timely response of Internet financial procts.

4. Ethereum, ETH for short. At the end of 2013, vitalik released the white paper of Ethereum, and in July 2014, the pre-sale of Ethereum began. At that time, insiders called this kind of token issue "crowdfunding". Through the 42 day pre-sale, the Ethereum team raised more than 30000 bitcoins through the pre-sale of 60102216 Ethernet coins; In addition, the early contributors who participated in the development before the pre-sale and the developers who have been engaged in project research for a long time are allocated according to 9.9% of the total amount of Ethernet coins sold at that time. So when Ethereum was officially released, there were more than 72 million Ethereum coins. After the end of Ethereum's pre-sale, it uses the proof of work mechanism POW for mining, and rewards the miners according to 26% of the total amount issued at that time every year. In October 2014, Ethereum reced the block output time from 60 seconds to 12 seconds, and now it is basically stable at 15 seconds, with 5 etheric coins awarded for each block
although the pow mining mechanism is adopted, the block out mechanism of Ethereum is different from that of bitcoin. Due to the short block time of Ethereum, Ethereum is easy to form isolated blocks. Isolated blocks refer to the blocks that are not on the longest chain. Bitcoin's isolated blocks have no block rewards, but in Ethereum, isolated blocks can be referenced. The referenced isolated blocks are called "Uncle blocks", and their packaged data will also be recorded in the blockchain. Unlike bitcoin, Ethereum's TERT block has a reward, and each TERT block can get a reward of 4.375 Ethernet coins at most
Ethereum is a programmable and Turing complete blockchain development platform, which is equivalent to a decentralized global computer. In a programming system, there are usually some virtual machines to compile and execute. Java has JVM. In Ethereum, there is also Ethereum's virtual machine EVM, which can execute any complex algorithm code. Developers can use existing programming languages such as JavaScript or Python to create their own applications on Ethereum. Through Ethereum's virtual machine, you can easily issue digital assets, write smart contracts, set up and run decentralized applications, and set up decentralized autonomous organizations
eth is also known as the internal fuel of Ethereum. Unlike currency digital assets, Ethereum is not only used for transfer, but also for payment of smart contracts
in order to prevent the Ethereum blockchain from being full of junk contracts and junk applications, and to establish and run smart contracts on Ethereum, you must use eth to pay for smart contracts. For example, when you transfer your newly created digital assets on the Ethereum blockchain, you need to use eth to pay the handling fee instead of your newly created digital assets.

5. Ether clown is a digital and collectable blockchain game based on Ethereum blockchain. Using ether money to adopt clowns can be resold, and they can also be used to breed a new generation of clowns with strange shapes. They can also be cultivated to work and earn money, which makes the digital collection of clowns more sustainable and playable.

6.

The public chain is open to all, the private chain is open to indivials who meet specific conditions, and the alliance chain is open to authorized organizations or institutions

public chain, also known as public blockchains, refers to a consensus blockchain that can be read by anyone in the world, sent by anyone, and effectively confirmed

private chain, also known as fully private blockchains, refers to the blockchain in which the write permission is completely in the hands of an organization, and all nodes participating in the blockchain will be strictly controlled

alliance chain, or alliance blockchains, refers to a blockchain that is managed by several organizations or institutions. Each organization or institution controls one or more nodes and records transaction data together. Only these organizations and institutions can read, write and send transaction data in the alliance chain

< H2 > extended data:

blockchain has three types: public chain, private chain and alliance chain

blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies

blockchain is an important concept of bitcoin. It is essentially a disintermediated database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains the information of a bitcoin network transaction, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

< H2 > reference: blockchain network

7. The degree of decentralization of public chain. This kind of public blockchain, represented by bitcoin and Ethereum, is not controlled by a third party. All people in the world can read the data records on the chain, participate in transactions and compete for the bookkeeping rights of new blocks
program developers have no right to interfere with users, and each participant (i.e. node) can freely join and exit the network, and carry out relevant operations according to their wishes
private blockchain is on the contrary. The write permission of the network is fully controlled by an organization or institution, and the data read permission is regulated by the organization, either open to the outside world or with a certain degree of access restrictions
in short, it can be understood as a weakly centralized or multi centralized system. Because the participating nodes are strictly limited and few; Compared with public chain, private chain has shorter time to reach consensus, faster transaction speed, higher efficiency and lower cost
the alliance chain is a blockchain between the public chain and the private chain, which can realize "partial decentralization"
each node in the chain usually has its corresponding entity or organization; Participants join the network through authorization and form a stakeholder alliance to jointly maintain the operation of the blockchain.

8. This link. If you start the geth client locally, the page will display the following information:
you can see the account balance under balance (ethers). The unit is ether

2. In the command line, geth console. Starts the control terminal of Ethereum
when & quot& gt;& quot; At the prompt, enter Web3. From Wei (ETH. Getbalance (ETH. Coinbase), & quot; ether") After that, press enter to confirm
the account balance will be displayed. The unit is ether.

9. The professional casing manufacturers proce and process casings according to API Spec 51988 and SY / t6194-96
there are 10 grades of steel procts: H40, J55, K55, N80, C75, L80, C90, C95, P110 and q125
proction range: oil casing
4-1 / 2 & quot
to
20 & quot
(usually seamless pipe)
button type: BTC, LTC, STC
for N80 casing, the manufacturer's proction length is R-1 (4.88-7.62m), R-2 (7.62-10.36m) and R-3 (10.36m-longer)
the surface defects of unqualified N80 casing include fish scale fold, slag inclusion fold and slag pit. When choosing the cooperative manufacturer, we should pay more attention to the time and place of the manufacturer
through negotiation between the manufacturer and the demander, submerged arc welded straight seam pipe can be used for large diameter casing (diameter greater than 508mm) used to transport natural gas, gas, oil, water and other liquids and gases
in order to rece the cost, improve the safety and prolong the service life of the casing of the demander, the type of pipe end buckle can be selected as long round thread, partial trapezoidal thread, short round thread and special buckle. The Demander shall specify the type of pipe end buckle in the contract when selecting< The mechanical properties control requirements of N80 raw materials selected by the manufacturer:
in order to make the mechanical properties of N80
grade (36Mn2V)
hot rolled seamless tube meet the API requirements, it is stipulated that the continuous casting slab is heated evenly, the starting rolling temperature is controlled at 1150 ~ 1220
℃, the rolling rhythm is well controlled, and the finishing rolling temperature is 920 ~ 950
℃< N80 oil casing pipe is a kind of seamless steel pipe with high strength and toughness.
the commonly used methods in the world are as follows:
quenching and tempering (including direct quenching and tempering after rolling), normalizing, normalizing +
tempering and tempering after rolling
36Mn2V
is a special steel for N80
grade oil casing, which belongs to microalloyed non quenched and tempered steel. The steel is suitable for processing by temperature control, cooling control and deformation control. The steel pipe can achieve the required performance without quenching and tempering, thus simplifying the proction process and recing the manufacturing cost of steel pipe
the demander's conversion of common units in the inquiry sheet of casing manufacturer: outer diameter 25.4mm = 1in, weight 1.49kg/m
= 1lb / ft, length 1m = 3.28ft.

10. Ethereum is also a proct of blockchain 2.0, which is an open intelligent contract complete solution. Bitcoin is the most important application of blockchain 1.0, which completes currency and payment transactions well. But when we need to record and transfer more complex asset types, we need the third step - a more powerful scripting system - to finally achieve Turing completeness (the ability to run any currency, protocol or blockchain). Ethereum is a blockchain based project, which aims to provide a Turing complete scripting language and Turing complete platform

blockchain 1.0 mainly refers to bitcoin. Blockchain 2.0 extends to all assets, while blockchain 3.0 goes beyond currency, finance, even commerce, and all areas of our lives, including politics, social relations, ecation, medical care, etc. According to the prediction and conception of people in the instry, the era of blockchain 3.0 will be realized in the next five years. At that time, blockchain will be recognized and accepted by all the public like the Internet, thus completely subverting our lives

McKinsey has submitted a technical report on blockchain to the Federal Insurance Advisory Committee of the United States. The report calls 2009-2016 the "Dark Age" and believes that all blockchain solutions ring this period are based on bitcoin, and the new era of blockchain will begin in 2016. At that time, the application of blockchain will become unprecedented. Applying an original sentence in McKinsey report: Based on the current development speed of blockchain, we believe that blockchain solutions may realize their full potential in the next five years.