Blockchain front end page

1.

EOS is a public chain system at the bottom of blockchain developed by block. One, which is specially designed to support decentralized application of Commerce, and its code is open source

bitcoin is called blockchain 1.0 because it opens up the world of digital cryptocurrency and takes a decisive step from 0 to 1

Ethereum is known as blockchain 2.0, because it provides Turing complete virtual machine that can run smart contracts, bringing unlimited possibilities

and EOS is called blockchain 3.0, why? Two words: performance

The positioning of EOS is the slogan of its home page:

English: the most powerful infrastructure for decentralized applications

Chinese: the most powerful decentralized application infrastructure

EOS expects to be an enhanced version of Ethereum, a high-throughput intelligent contract platform

although Ethereum has complete functions, it is limited by its design choice. Due to the block output speed of 15 seconds, the transaction throughput is far from large-scale practical level, which is only about 30 ~ 40tps (transaction / s). EOS, on the other hand, has chosen a different technology route, with the goal of achieving a considerable million TPS, which is quite attractive considering visa's actual processing speed of 1700tps

consensus mechanism of EOS

the reason why the throughput of bitcoin and Ethereum is so low is that they are constrained by the application scenario they envision and the consensus mechanism they choose for the scenario - both of them assume that the environment in which the system runs is totally untrustworthy, so they both adopt the consensus mechanism of proof of work

consensus, as the name suggests, is to reach a unified understanding of something - for blockchain, something refers to the confirmation of the transaction - any node to submit a transaction needs everyone's approval

the pow mechanism currently adopted by bitcoin and Ethereum is the design of the legendary Nakamoto Tsung. Under this mechanism, in order to obtain the bookkeeping right and digital currency reward, miners need to constantly dig for the compliant hash value, and confirm and package the transaction data through the consensus of hash value. POW has no access threshold, and any node has equal rights to participate in bookkeeping. Of course, the probability of winning is related to computing power:

the price of ram is based on Bancor algorithm, that is, it is regulated by market supply and demand: if the supply of ram exceeds the demand, more EOS certificates are needed to buy ram, At this time, more EOS certificates can be obtained by selling ram

memory is a consuming resource, which cannot be redeemed and can only be bought and sold. Take the issue of currency on EOS as an example. At present, the issue of currency requires 20m of memory. An EOS can buy 20KB. According to the current storage price, issuing a currency will consume 1000 EOS. This is the source of EOS memory consumption

Course Overview

this course is for friends who are interested in the development of EOS decentralized application. The course covers the core concepts of EOS DAPP development, the development and deployment of smart contracts, and how the front page interacts with EOS blockchain. Finally, a complete DAPP development based on react and EOS is completed

Chapter 1: enter the world of EOS

to understand the core concepts of EOS, such as positioning and characteristics, consensus mechanism, payment computing model, etc

Chapter 2: Hi EOS

understand the overall framework of EOS node software and the functions of node server, wallet server and command-line tools, learn how to configure and start EOS node server and wallet server, and preliminarily understand the use of command-line tools

Chapter 3: wallet, key and account

understand the three core concepts related to personal identity in EOS: wallet, key and account, and learn how to use command-line tools to create wallet, key and account

Chapter 4: development and interaction of smart contracts

understand the concept and function of smart contracts, learn how to write and compile EOS smart contracts, and learn how to deploy and interact with contracts using command-line tools

understand the persistence mechanism of state in EOS smart contract, and learn to use multi index table to save contract state

Chapter 5: issue your own tokens

learn the principle and implementation mechanism of issuing tokens on EOS, and master how to use command-line tools to issue, transfer and view the balance of tokens through practical operation

Chapter 6: use code to interact with smart contract

understand the principle of interaction between application and EOS blockchain, and learn to use JSON RPC interface and eosjs encapsulation library to access EOS blockchain

Chapter 7: DAPP development of practical notes

comprehensively use EOS knowledge, use react to complete a decentralized application of EOS notes, and learn the complete process from requirement analysis to code implementation

The above course address is as follows: EOS tutorial

2. I can only say that this is an emerging instry. We should not care too much about the immediate gains and losses of interests. We should look at the long term, and opportunities are more important

blockchain technology is only a technical means of recording information, and its main characteristics are decentralization and transparency, which can be applied in any instry. The traditional mode of recording information needs the credit of the recorder to endorse it, and people have to pay for the credit cost. Compared with the traditional way of information recording, blockchain has unique advantages: everyone can record, and everyone has all the recorded information, which also means recing the cost of reputation. The so-called blockchain instry itself is a pseudo proposition, and technical means can be applied to any instry.

3. 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.

4. 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

5. GT has no erc20 token on Ethereum

6. In what area

7. be necessary! The premise is that economic conditions permit
confinement in the confinement center is concive to maternal physical recovery. Confinement in the confinement center can prevent postpartum depression, and the baby can also be taken care of comprehensively. After childbirth, post-90s mothers are worried about skin yellowing, body deformation, pregnancy marks and so on. The confinement center has special nursing staff to take care of them, so they should be more careful.

8. The reason is that the three-phase load should be balanced as far as possible. That is to say, the total power of single-phase electrical appliances connected to the three live wires should be balanced as far as possible to avoid the situation that the power of electrical appliances connected to one phase is too much or too little. In addition, when there are three-phase motor equipment, Different phase of three wire connection may cause the motor to turn in the opposite direction, so the phase of three-phase socket should be ensured as far as possible, that is, the position of three live wires on the socket is consistent.