HH miner
public key system: corresponds to a public key and a private key, keeps the private key in the application and publishes the public key. When Party A transmits information to Party B, it can use Party A's private key to encrypt the information, and Party B can use Party A's public key to decrypt the information, so as to ensure that the third party cannot impersonate Party A to send the information; At the same time, when Party A transmits information to Party B, it is encrypted with Party B's public key and sent to Party B, and then Party B decrypts it with his own private key, so as to ensure that the third party cannot eavesdrop on the communication between the two people. RSA is the most common public key system, but the lliptic curve digital signature algorithm is used in bitcoin protocol. What's the difference between cash and bank account? Bitcoin is an electronic currency in BTC. In this article, it is also used to refer to the whole bitcoin system. Like opening an account in a bank, the corresponding concept in bitcoin is address. Everyone can have one or more bitcoin addresses, which are used to pay and collect money. Each address is a string that starts with 1. For example, I have two bitcoin accounts, and. A bitcoin account is uniquely determined by a pair of public key and private key. To save the account, you only need to save the private key file. Unlike bank accounts, banks keep all transaction records and maintain the book balance of each account, while bitcoin's transaction records are jointly maintained by the whole P2P network through a pre agreed protocol. How much money is in my account address? Although the current account balance can be seen by bitcoin software, unlike banks, there is no place to maintain the book balance of each address. It can only calculate the account balance in real time through all historical transactions. How do I pay? When I pay from address a to address B of the other party, the payment amount is e. at this time, both parties will announce the transaction information to each network node, telling address a to pay to address B, and the payment amount is e. In order to prevent the third party from forging the transaction information, the transaction information will be encrypted with the private key of address A. at this time, the network node receiving the transaction information can use the public key of address a to verify that the transaction information is indeed sent by address a. Of course, trading software will help us do these things, we just need to input the relevant parameters in the software. What will the network node do after receiving the transaction information? This is the most important part of the bitcoin system, which needs to be elaborated. For the sake of simplicity, only bitcoin protocol has been implemented. In the current version, each network node will save all transaction information synchronously. There are two kinds of transaction information in history, one is & quot; Verified & quot; The transaction information, that is, the verified transaction information, is stored in a series of "blocks". Each & quot; block" Is the previous & quot; bock" The ID of each block is the hash code of the hash code of the block and the new transaction information (see an actual block). The other category refers to those who also & quot; Unverified & quot; The transaction information just paid above belongs to this category. When a network node receives new unverified transaction information (possibly more than one), it can calculate the book balance of each address at that time because the node keeps all the transaction information in history, so it can calculate whether the transaction information is valid, that is, whether there is enough balance in the payment account. After eliminating the invalid transaction information, it first takes out the last & quot; block" Then, the unverified transaction information is combined with the ID, and a verification code is added to form a new "block". It needs a lot of calculation to build a new block, because it needs to calculate the verification code, so that the above combination becomes a block, that is, the first several bits of the hash code of the block are 1. At present, the first 13 bits need to be 1 (generally, the specific method is uncertain), which means that if the block is generated by enumeration method, the average number of enumerations is 16 ^ 13. Using CPU resources to generate a block is called "gold mining", because the proction of the block will get a certain reward, and the reward information has been included in the block. When a network node generates a new block, it will broadcast to other network nodes. However, this network block may not be accepted by the network, because it is possible that other network nodes have proced the block earlier. Only the earliest block or the block with the largest number of subsequent blocks is valid, and the remaining blocks are no longer used as the initial blocks of the next block. How does the other party confirm that the payment is successful? When the payment information is distributed to the network node, the network node begins to calculate whether the transaction is valid (that is, whether the account balance is enough to pay), and attempts to generate blocks containing the transaction information. When six blocks (one direct block and five subsequent blocks) contain the transaction information, the transaction information is considered "verified", so that the transaction is formally confirmed, and the other party can confirm the successful payment. A possible problem is that I will pay the balance of address a to address B, and at the same time pay to address C. If I only verify that the single comparison transaction is valid. At this point, my way of cheating is to generate six blocks including B to B and six blocks including C to C before the truth is revealed. Because I need a very long CPU time to generate a block, compared with the whole network, the probability of my cheating success is very small. What is the motivation of network nodes to proce blocks? As can be seen from the above description, in order to make the transaction information effective, the network node needs to generate 1 and 5 subsequent blocks to contain the transaction information, and such block generation is very CPU intensive. How to let other network nodes help to proce blocks as soon as possible? The answer is very simple. The agreement stipulates that BTC will be rewarded for the address where the block is proced, as well as the Commission promised by both parties. At present, the reward for procing a block is 50btc, which will be halved every four years in the future. For example, the reward will be 25btc from 2013 to 2016. Is the transaction anonymous? Yes, and No. All bitcoin transactions are visible. We can check all transaction records of each account, such as mine. But what's different from the banking monetary system is that everyone's account itself is anonymous, and everyone can open many accounts. In general, anonymity is not as good as it claims. But bitcoin has another advantage in doing black market trading: it can't be frozen. Even if the police trace a bitcoin address, there is nothing they can do unless they trace the computer used by the exchange based on the Internet address. How to ensure that bitcoin does not depreciate? Generally speaking, in the case of equivalent trading activities, the value of money is inversely proportional to the amount of money issued. Unlike the traditional money market, the central bank can determine the amount of money issued. Bitcoin does not have a central issuing institution. Only by procing blocks can we get a certain amount of BTC currency. Therefore, bitcoin's new amount of money depends on: 1. The speed of procing blocks: bitcoin's agreement stipulates that the difficulty of procing blocks is fixed at an average of 2016 every two weeks, about 10 minutes. Moore's law of doubling CPU speed every 18 months will not speed up the proction of block. 2. The number of rewards for block proction: at present, 50 BTC is awarded for each block proced, which is halved every four years. In 2013, 25 BTC is awarded, and in 2017, 12.5 BTC is awarded. Considering the above two factors, bitcoin's currency issuing speed is not controlled by any single node in the network. Its protocol makes the currency stock known in advance, and the maximum stock is only 21 million BTC
At present, the mining machines in the market are mainly divided into two categories, one is PC based mining machine, the other is professional mining machine based on ASIC chip
the general PC mining machine can be used as a home computer, but the CPU performance is weak and the power consumption is high. Professional mining machine based on ASIC chip can not be used as ordinary computer because it has no graphics card and does not support mainstream desktop operating system
extended data:
mining machine is one of the ways to obtain Bitcoin is a kind of network virtual currency proced by open source P2P software. It doesn't rely on a specific currency institution to issue, but is generated by a large number of calculations of a specific algorithm. It uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions economically. The decentralized nature of P2P and the algorithm itself can ensure that the currency value cannot be manipulated by mass proction
any computer can become a mining machine, but the profit will be relatively low, and there may not be one in ten years. Many companies have developed professional mining machines, which are equipped with special mining crystal. They are tens or hundreds of times higher than ordinary computers
mining is actually a competition of performance and equipment. The mining machine composed of many graphics cards, even if it is just a garbage card like hd6770, can surpass the single graphics card of most users in terms of computing power
and this is not the most terrible. Some mining machines are made up of more such graphics card arrays. When dozens or even hundreds of graphics cards come together, the graphics card itself costs money. Considering the hardware price and other costs, there are considerable expenses in mining
in addition to the display card burning machine, some ASIC (application specific integrated circuit) professional mining machines are also put into the battlefield. ASIC is specially designed for hash operation. Although the performance may not be able to kill the display card in seconds, it is already quite strong. Moreover, because their power consumption is far lower than that of the display card, it is easier to form scale and the electricity cost is also lower, It is difficult to compete with these excavators. And this kind of machine will be more expensive
in other words, there are a lot of "mining machine graphics cards" on Taobao, because these graphics cards use less materials under the same core and basically unchanged hash speed, such as recing video memory to improve the performance price ratio (the size of video memory has little to do with the mining speed), which can shorten the time to recover the cost
in short, the graphics card of mining machine is the core of common high-end graphics card + the workmanship of low-end graphics card, or some cheap medium and high-end public graphics card.
in short, mining is to use the chip to carry out a calculation related to the random number, and get the answer in exchange for a virtual coin. Virtual currency can be exchanged for the currency of each country through some way. The stronger the computing power, the faster the chip can find this random answer. Theoretically, the more virtual coins can be proced per unit time. Because it's about random numbers, you can only get rewards if you happen to find the answer. It's possible that one chip will find the answer in the next second, or ten chips won't find the answer in a week. The more chips compute at the same time, the easier it is to find the answer, and the mining machine with built-in multi chips appears. And a number of mining machines to form a "mine" at the same time mining is to improve efficiency. In the mine pool, multiple "self-employed" join an organization to mine together. No matter who finds the answer and digs out the virtual coin, everyone gets the corresponding reward according to the calculation ability of contribution. This way can make the income of "self-employed" more stable
take a popular example:
I write a string of numbers on a piece of paper and give some hints. Whoever guesses correctly will be given a bonus (mining)
smart people can make more guesses (calculation ability)
some people pay money to invite many people to come back and guess together (mining)
some people call everyone together to guess, no matter who guesses, Distribute the bonus (mine pool) according to the proportion of guessing times of each person
the rest is too long, you can search by yourself...
at present, one bitcoin is divided into eight decimal places, namely 0.00000001btc, based on the current data structure. The smallest unit of bitcoin g by miners is 0.00000001btc
generally speaking, bitcoin is like a gold mountain composed of 21 million gold coins. To get it, players need to use the computing power of the computer to calculate a group of numbers that conform to specific rules according to the existing algorithms.
Sae8620 is a kind of alloy structural steel specified in American Standard
The difference between sae8620 and SAE8620H is whether the hardenability is guaranteed or not, and the band h indicates the guaranteed hardenabilityexecutive standard: saej404
sae8620 chemical composition is as follows:
mass fraction (%):
C: 0.18 ~ 0.23
Si: 0.15 ~ 0.35
Mn: 0.70 ~ 0.90
s: allowable resial content ≤ 0.035
P > P: allowable resial content ≤ 0.035
Cr: 0.40 ~ 0.60
Ni: 0.40 ~ 0.70
Mo: 0.15 ~ 0.25
Cu: allowable resial content Resial content ≤ 0.30
sae8620 standard information is as follows:
turn left | turn right
In 1847, Edison came from an ordinary American family. As a child, he was curious about everything around him. He always asked more questions about why than others. One day it was time for dinner, but his mother found that Edison had disappeared. The whole family searched for him and finally found him in the chicken nest. It turned out that he saw the hens hatch chickens, and he wanted to have a try. Another time, he let the neighbor's little friend, Milly, eat baking powder, hoping that he could fly like a balloon. As a result, instead of flying, he almost died, causing his parents and children to sue Edison
At the age of7, Edison went to school and asked why as he used to. The teacher taught us: 2 + 2 = 4. He asked why 2 plus 2 should be equal to 4. Although the teacher gave him a general answer, he was still not satisfied. He was so angry that the teacher scolded him for being incompetent and asked him to drop out of school. Mother brought Edison back home. In this way, one of our great inventors was driven home after only three months of school. The reason is that the teacher thought he was too stupid
Edison was taught mathematics, writing, chemistry and nature by his mother at home. Edison always had a great interest in learning, especially in chemistry. He saved his pocket money and bought all of them into chemical supplies. He built a small chemical laboratory in the cellar of his home. Every day he did experiments in it except reading When he was young, Einstein was a very playful child. His mother was often worried about it, and his mother's repeated admonitions were like a breeze in his ears. One morning in the autumn when he was 16 years old, his father stopped Einstein who was going to drop fish by the river and told him a story, which changed Einstein's life. Here's the story“ Yesterday, "Einstein's father said," my neighbor Uncle Jack and I went to clean a big chimney in the South factory. That chimney can only go up by stepping on the steel ladder inside. Uncle Jack is in front of you, and I am in the back; We grabbed the handrail and finally climbed up one by one. When you come down, Uncle Jack is still in the front, and I am still following him. Later, when we got out of the chimney, we found a strange thing: your Uncle Jack's back and face were all blackened by the soot in the chimney, but I didn't have any soot. " Einstein's father continued to smile and said, "I saw Uncle Jack in his early years and thought that I must be the same as him, with a dirty face like a clown, so I went to the nearby river to wash and wash. As for Uncle Jack, he thought he was as clean as me when he saw me coming out of the chimney, so he just washed his hands and went on the street. As a result, people in the street laughed and hurt their stomachs. They thought Uncle Jack was a madman. " Einstein couldn't help laughing with his parents. After laughing, his parents solemnly said to him: "in fact, no one else can be your mirror, only you are your own mirror. Take others as a mirror, an idiot may turn himself into a genius. " Einstein's face was filled with shame Einstein left those naughty children from then on. He always used himself as a mirror to examine and reflect himself, and finally reflected the brilliance of his life Al had only three months of schooling in his lifeStory 3 of Edison. His success should be attributed to his mother's understanding and patient teaching since childhood, which made Edison, who was originally regarded as an incompetent child, become a world-famous "king of invention" when he grew up
Edison was curious about many things since he was a child, and he liked to test them himself until he understood the truth. When he grew up, he devoted himself to research and invention according to his own interests. He set up a laboratory in New Jersey and invented more than 2000 kinds of things in his life, such as electric lamp, telegraph, phonograph, video camera, magnetic separator, crusher and so on. Edison's strong research spirit made him make great contribution to the improvement of human life style
"waste, the biggest waste is to waste time." Edison often said to his assistant“ Life is too short. Think more and do more with less time. "
One day, Edison was working in the laboratory. He handed his assistant an empty glass bulb without a light port and said, "you measure the capacity of the bulb." He bowed his head to work again After a long time, he asked, "what's the capacity?" He didn't hear the answer. He turned his head and saw his assistant measuring the perimeter and inclination of the bulb with a tape measure. He took the measured number and put it on the table to calculate. He said, "time, time, how do you spend so much time?" Edison came over, picked up the empty light bulb, filled it with water, handed it to his assistant, and said, "pour the water in the measuring glass, and tell me its capacity right away." The assistant immediately read out the number Edison said: "what an easy way to measure, it's accurate and time-saving. How can you not think of it? Is it not a waste of time? " The assistant blushed Edison murmured: "life is too short, too short. Save time and do more things!" Edison was a poor worker before he became famous. Once, his old friend met him in the street and said with concern, "look, this overcoat on you is not in good condition. You should replace it with a new one.""do you need it? "No one knows me in New York," Edison replied nonchalantly
A few years later, Eddie became a great inventor One day, Edison met his friend on the street of New York“ "Oh," exclaimed the friend, "Why are you still wearing this old coat? This time, you need a new one anyway"do you need it? Everyone here already knows me. " Edison still answered with indifference
When Edison was 12 years old, he was addicted to scientific experiments. After tireless self-study and experiments, he invented the automatic telegraph that sends one signal per hour when he was 16 years old. Later, he successively invented the automatic counting machine, the first practical typewriter, double and quadruple telegraph, automatic telephone and phonograph. Edison was not satisfied with these inventions. In September 1878, Edison decided to attack the fort of electric lighting. He read a lot of books about electric lighting, determined to proce cheap, rable, safe and convenient electric lights He started with the white heat lamp. Put a small piece of heat-resistant material in a glass bubble, and when the current burns it to white heat, it will glow from heat. He first thought of carbon, so he put a small piece of carbon wire into the glass bubble. As soon as he was electrified, it broke"what is the reason?" Edison picked up the broken carbon wire and looked at the glass bubble. After a long time, he suddenly thought, "Oh, maybe because there is air in it, and the oxygen in the air helps the carbon wire burn, so it breaks immediately!" So he used his hand-made ventilator to pump the air out of the glass bubble as much as possible. As soon as the power was on, it didn't turn off immediately. But eight minutes later, the light went out
However, Edison finally found out that white heat lamp is very important in vacuum state, and the key is carbon wire, which is the crux of the problemso what kind of heat resistant material should be chosen
Edison thought, the highest melting point, strong heat resistance, to be platinum! So Edison and his assistants tried platinum several times, but although this kind of platinum with high melting point prolonged the light-emitting time a lot, it was still not ideal to automatically turn off and then light up from time to time
Edison was not discouraged and continued his experimental work. He has tried barium, titanium, Gu and other rare metals, the effect is not very ideal After a period of time, Edison made a summary of the previous experimental work and wrote down all kinds of heat-resistant materials he could think of, with a total of 1600 kindsnext, he and his assistants began to test these 1600 kinds of heat-resistant materials in different categories, but platinum is the most suitable choice. Due to the improvement of the air extraction method, the vacuum degree in the glass bulb is higher, and the service life of the lamp has been extended to 2 hours. But the price of this kind of lamp made of platinum is too expensive. Who is willing to spend so much money to buy an electric lamp that only takes two hours
The experiment work fell into a low ebb, and Edison was very distressed. One cold winter, Edison was sitting around the fire, looking at the blazing charcoal fire, and he couldn't help saying to himself: "charcoal......the charcoal strips made of charcoal had been tried, what should he do? Edison felt hot and dry, so he pulled off the scarf on his neck. Seeing the scarf made of cotton yarn, Edison suddenly had an idea in his mind:
Yes! The fiber of cotton yarn is better than that of wood. Can we use this material
he quickly pulled a piece of cotton yarn from his scarf and baked it on the fire for a long time. The cotton yarn turned into charred charcoal. He carefully put the carbon wire into the glass bubble, a test, the effect is really good
Edison was very happy, and then he made a lot of carbon fibers made of cotton yarn, and carried out many tests continuously. The life of the lamp was extended by 13 hours at a time, and then by 45 hours As soon as the news spread, it caused a sensation all over the world. The stock price of London gas fell sharply, and the gas instry was in chaos. People have a premonition that lighting gas lamps will become history, and the future will be the era of electricity and lighteveryone congratulated Edison one after another, but lovely Edison didn't look happy at all. He shook his head and said, "no, we have to find other materials!"
"why can't I light up for 45 hours?" The assistant asked in surprise“ no way! I hope it lights for 1000 hours, preferably 16000 hours! " Edison replied
as you all know, it's good to light up for more than 1000 hours. What materials are suitable for you
Edison had the number in his mind. According to the nature of cotton yarn, he decided to look for new materials from the aspect of plant fiber So the marathon experiment began again. Edison experimented with all kinds of plant materials as long as they could be found. He even experimented with horse manes, human hair and beards as filaments. Finally, Edison chose bamboo. Before the experiment, he took out a piece of bamboo, looked at it with a microscope, and jumped up with joy. As a result, the carbonized bamboo filament is put into the glass bubble, and after being electrified, this kind of bamboo filament light bulb lights continuously for 1200 hours Edison was relieved at last, and his assistants congratulated him one after another, but he said seriously: "there are many bamboos in different parts of the world, and their structures are not the same