Ethereum private key set to 1

1. The term "difficulty" comes from bitcoin, the pioneer of blockchain technology, which is used to measure the average number of operations needed to dig out a block. mining is essentially solving a puzzle. Different e-coins set different puzzles. For example, bitcoin uses SHA-256, lightcoin uses script, and Ethereum uses ethash. All the possible values of the solution of a puzzle are called the solution space. Mining is to find a solution among these possible values
these puzzles

2. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)

3. Wait, Ethereum is a public chain. Do you mean the token issued above? You can set the total amount

4. Ethereum is a distributed computing platform. It generates an cryptocurrency called ether. Programmers can write "smart contracts" on the Ethereum blockchain, and these Ethereum smart contracts will be executed automatically according to the code

what is Ethereum
Ethereum is often compared with bitcoin, but the situation is different. Bitcoin is a kind of cryptocurrency and distributed payment network, which allows bitcoin to be transferred between users

related: what is bitcoin? How does it work

Ethereum has a bigger goal. As Ethereum says, "Ethereum is a distributed platform running smart contracts.". These smart contracts run on "Ethereum virtual machine", a distributed computing network composed of all devices running Ethernet nodes

"distributed platform" means that anyone can set up and run an Ethereum node just as anyone can run a bitcoin node. Anyone who wants to run "smart contracts" on nodes must pay the operators of these nodes in ether, which is a cryptocurrency related to Ethereum. Therefore, the person running the Ethernet node provides computing power and gets paid in the Ethernet, which is similar to the way that the person running the bitcoin node provides hash power and pays in bitcoin

in other words, although bitcoin is only a blockchain and payment network, Ethereum is a distributed computing network, and its blockchain can be used for many other things. Details are provided in the Ethereum white paper

what is ether
Ethernet is a digital token (or cryptocurrency) related to Ethereum blockchain. In other words, Ethereum is the token and Ethereum is the platform. But now people often use these terms alternately. For example, coinbase allows you to buy Ethereum, which stands for Ethereum

this is technically "altcoin", which actually means a non bitcoin cryptocurrency. Like bitcoin, ether is supported by distributed blockchain - in this case, Ethereum blockchain

developers who want to create applications or Ethereum smart contracts on Ethereum blockchain need Ethernet token to pay for nodes to host it, while users of Ethereum based applications may need Ethernet to pay for services in these applications. People can also sell services outside the Ethereum network and accept Ethernet payments, or they can sell Ethernet tokens in cash - just like bitcoin

5. If it's lost, it's better to post the lost advertisement

6. Confinement is a thing that must be done after childbirth. If you don't take delivery, the maternal body will leave the root of the disease after pregnancy, which is difficult to cure. Pregnant women can choose to take delivery at home or in the delivery center

first of all, confinement is usually for one month. So whether at home or in the confinement center is the same, it needs to live for a month. But this time is not certain, can only be said to be at least a month's time to live. A month is a minimum time, even if the maternal recovery is fast, but also to live enough for a month. But if the maternal recovery is relatively slow, then it is not only to live for a month, it is necessary to live longer. Therefore, it is more recommended that pregnant women take delivery at home, which is more convenient and comfortable<

secondly, confinement is the key period for a newborn baby to recover. During this period, it is necessary to take good care of the baby. The time of each confinement is different, but it is generally 30 days or 42 days, so the body will recover more completely

in the end, the place to take delivery of the baby must choose a better place, a place with more complete facilities and better service. Otherwise, if the pregnant woman goes to the delivery center and no one is in charge, the delivery of the baby will be greatly reced

pay attention to diet after childbirth:

women have higher requirements for diet when they are in confinement, and many women think that there are not so many restrictions after childbirth, but as long as women are still in lactation, there are still many things to pay attention to

1. During lactation, women should not eat food with milk returning function, such as leek, malt, etc. Many women think ginseng tonic body is very effective, but ginseng will make maternal milk, in breast-feeding, it is best not to eat. In addition, more estrogen content of food is also easy to cause milk, such as pigeons, hens and so on

2. Women should not eat caffeinated food ring lactation. Caffeine can stimulate the nervous system. It is likely to enter the child's body through milk, causing damage to the child's nervous system and heart, and also causing indigestion

3. Eat less salt and monosodium glutamate, too much salt will increase the burden on the kidney. And monosodium glutamate will affect the development of children, eat too much monosodium glutamate will make children appear mental retardation, growth retardation and so on

women should not only pay attention to their diet when they are in confinement, even when they are out of confinement, as long as they are still in the lactation period, they can not do whatever they want in their diet, so as not to have adverse effects on their children.

8.

Through the method of experiment, the cutting force data of various influencing factors are measured, and the expression reflecting the relationship between various factors and cutting force is obtained by processing, which is called the empirical formula of cutting force calculation

In practice, there are two empirical formulas of cutting force: one is exponential formula, the other is unit cutting force. Exponential formula: FC = KC & # 8226; ap• f=kc• hd• bd kc=Fc/A d=Fc/(a p• f)=F c/(b d• h d)

FP -- back force (n)

Ff -- awesome force (N). p>

extended data:

compared with ordinary machine tools, CNC machine tools have the following characteristics: high machining accuracy and stable machining quality; high precision and stable machining quality; It can carry out multi coordinate linkage, and can process complex parts; When the machining parts are changed, generally only the NC program needs to be changed, which can save the proction preparation time

the machine tool itself has high precision and rigidity, and can choose favorable processing amount, with high proctivity (generally 3 ~ 5 times of that of ordinary machine tool); High degree of automation of machine tools can rece labor intensity; The quality of operators is required to be higher, and the technical requirements of maintenance personnel are higher

9. t you," the matron said, "

10.

Transaction

the behavior of blockchain transaction follows different rule sets

< UL >

e to the distributed and unlicensed nature of public blockchain, anyone can sign the transaction and broadcast it to the network

according to different blockchains, traders will be charged a certain transaction fee, which depends on the needs of users rather than the value of assets in the transaction

blockchain transactions do not require any central authority verification. It only needs to use the digital signature algorithm (DSA) corresponding to its blockchain to sign it with the private key

once a transaction is signed, broadcast to the network and mined into a successful block in the network, the transaction cannot be recovered

Ethereum transaction structure

Ethereum transaction data structure: transaction 0.1 eth

{
& 39; nonce':&# 39; 0x00', // Decimal: 0
& 39; gasLimit': &# 39; 0x5208', // Decimal system: 21000
& 39; gasPrice': &# 39; 0x3b9aca00', // Decimal system: 10000000000
& 39; to': &# 39;&# 39; ，// Sending address
& 39; value': &# 39; 0x16345785d8a0000',// 100000000000000000 ，10^17
' data': &# 39; 0x', // Decimal representation of null data; chainId': 1 / / blockchain network ID
}

these data have nothing to do with the transaction content, but have something to do with the execution mode of the transaction. This is because when you send a transaction in Ethereum, you must define some other parameters to tell miners how to handle your transaction. Transaction data structure has two attribute designs & quot; gas": & quot; gasPrice",& quot; gasLimit"

" gasPrice": The unit is Gwei, which is 1 / 1000 eth, indicating the transaction cost

& quot; gasLimit": The maximum gas charge allowed for the transaction

these two values are usually filled in automatically by the wallet provider

in addition, you need to specify which Ethereum network to execute the transaction (chainid): 1 represents the Ethereum main network

ring development, tests are usually carried out locally and on the test network, and transactions are carried out through the test eth issued by the test network to avoid economic losses. After the test, enter the main network transaction

in addition, if you need to submit some other data, you can use & quot; data" And & quot; nonce" Attach as part of a transaction

a nonce (number used only once) is the value used by Ethereum to track transactions, which helps to avoid double spending and replay attacks in the network

Ethereum transaction signature

Ethereum transaction involves ECDSA algorithm. Taking JavaScript code as an example, the popular ethers.js is used to call ECDSA algorithm for transaction signature

const ethers = require(' ethers')

const signer = new ethers.Wallet(' Wallet address

signer.signTransaction({

' nonce':&# 39; 0x00', // Decimal: 0

& 39; gasLimit': &# 39; 0x5208', // Decimal: 21000

& 39; gasPrice': &# 39; 0x3b9aca00', // Decimal 10000000000

& 39; to': &# 39;&# 39; ，// Sending address

& 39; value': &# 39; 0x16345785d8a0000',// 100000000000000000 ，10^17

' data': &# 39; 0x', // Decimal representation of null data

& 39; chainId': 1 / / blockchain network ID

})

. Then (console. Log)

you can use the online application composer to deliver signed transactions to Ethereum. This is known as "offline signature.". Offline signatures are particularly useful for applications such as status channels, which are smart contracts that track the balance between two accounts and transfer funds after a signed transaction is submitted. Offline signature is also a common practice in dexes

you can also use online wallet to create signature verification and broadcast through Ethereum account

with Portis, you can sign a transaction to interact with the gas station network (GSN)

< / UL >

the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system