Mining nonce confirmation

1. 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.

2.

Bitcoin is actually a useless string of numbers, but it is recognized as useful, just like diamonds, antiques, calligraphy and paintings, game skin and so on. They can't be eaten or used, but we will recognize their value

"mining" just allows more people to participate in the construction of blockchain network. Is it really good that so many electricity charges are used to "calculate" a series of virtual values? Bitcoin is not a hedge. The price of bitcoin fluctuates greatly. Speculation on bitcoin may become rich overnight or become poor overnight. Bitcoin is not as safe as it claims. In 2014, the world's largest bitcoin trading website, mtgox, was hacked and went bankrupt, and the $467 million worth of bitcoin evaporated instantly. Criminals use it to launder money, evade taxes and so on. It is also quite difficult for the government to investigate. The above personal opinions are welcome to be criticized and corrected. Agree with me, please click like before you go, thank you! Like me, please pay attention to me, thank you again

3. Only if the field type is text type can all the query lines be added to the array:
. Version 2
. Local variable AA, integer type
. Local variable BB, text type, & quot; 0"
. Local variable field value 1, text type
. Local variable field value 2, text type
external database 1. Open the MDB database (take the running directory () + "& # 92; ZJ. MDB ",", ")
AA = external database 1. Query (" select * from ZJ where number = 1 ")
external database 1. To the first record (AA)
. Judge the loop first (external database 1. After the last record (AA) = false)
& #; Suppose table ZJ has only two fields
field value 1 = external database 1. Read (AA, 1)
field value 2 = external database 1. Read (AA, 2)
join member (BB, field value 1)
join member (BB, field value 2)
external database 1. To the next record (AA)
. Judge the end of the loop ()
external database 1. Close recordset (AA)

4. I also have such problems, waiting for the solution.

5. DWG to exchange format. CAS 8. The application program converts the exchange format. CAS to the exchange format of MAPGIS digital mapping. SLT and the corresponding point file. TXT 8. Read in the point file 8. Read in the exchange format of MAPGIS digital mapping. SLT. Then the MAPGIS digital mapping file. SUV can be converted to MAPG

6. HPV infection is not terrible, although there is no specific drug for the treatment of HPV, it does not mean that HPV can not be defeated; The history of human beings is also the history of conquering diseases. Human beings have been exposed to all kinds of viruses for a long time. Finally, human beings can reproce to today, which shows that there are anti virus genes in the human body, specifically manifested in the immune function of the human body; HPV is only one of the viruses. When the human body is infected with the virus, the human body will graally (a few patients will soon) form immunity to the virus. When the immune ability is strong enough, HPV will be eliminated; Therefore, a large number of medical statistics show that although the proportion of people infected by HPV is large, most of them are transient, that is, the virus will disappear naturally within 1-2 years (generally referred to as HPV infection). In fact, the process of the human body to defeat the influenza virus is the same. The final victory of the influenza virus depends on the human body's own immune ability, not the result of drug action. Medicine can only be symptomatic treatment, such as nasal congestion can use vasoconstrictor drugs to smooth the nasal cavity, fever can use antipyretic drugs to rece body temperature, cough can use antitussive drugs to rece cough symptoms. But none of the ingredients of these cold medicines can kill the mutated virus. All of them can relieve the symptoms. The reason for the recovery of cold is that the human body graally forms the immunity to the influenza virus in about 7 days, thus killing the virus in the body
there are some similarities between HPV infection and cold, both belong to virus infection. The difference is that for cold virus, the human immune system will quickly find this virus and quickly form immunity to it; HPV infection is different, because HPV only invades the skin and mucous epidermis, the human immune system often can not detect the virus infection, can not form an effective immune response in time, and can not kill the virus in time. However, after a long period of time, the human body will graally enhance its immunity to HPV, and the patients will eventually clear the infected HPV. In short, in the absence of specific drugs to kill HPV, most patients can overcome HPV only by relying on their own immune ability. When it comes to the specific treatment, drug or physical therapy can remove the exogenous verruca, which can eliminate a large number of viruses (verruca is the most concentrated part of the virus). Of course, a small amount of resial virus is inevitable, but even without drugs, nearly half of the patients with
can rely on their own immune ability to overcome the resial virus and no longer relapse
there is a close relationship between human immunity and emotion. When a person is depressed, his immunity will decrease significantly; According to the clinical data, people who are not in a good mood are more likely to suffer from a variety of diseases, including colds, and there are more and more reports about long-term depression which is easy to cause cancer; In short, most diseases related to immunity are also affected by emotions, including the probability of infection and the speed of recovery. In a word, if you have the confidence to overcome HPV, you can walk out of the shadow of your heart as soon as possible, live a normal life ahead of time and face life with a normal attitude when the disease is not cured, which will speed up the speed of strengthening your own immunity and eliminate HPV faster; We believe that optimistic, healthy mood is the second step to overcome condyloma acuminatum.

7. Let me give you an example of real name authentication on ABCC trading platform (I'm not using coin security, so... You know), you know. First of all, you can go to the personal information side to find the identity authentication, upload the front and back photos of your ID card or passport, and then upload the photos of yourself holding the ID card or passport and the paper with the name and date of ABCC exchange. After that is waiting for certification. ABCC exchange generally can see the certification results after 24 hours.

8. Open the "game report" and click the [my] button in the lower menu bar to open the page as shown in the figure
how to anonymize the game report results
click the "privacy management" to select the learning ranking list and slide the button to the right. After adding successfully, there will be the words of "successfully modified"
how to anonymize the game report results
end
precautions
note: when you directly open the ranking list of performance points, This place will automatically default to allow full name display, that is to say, privacy settings are set, so you don't have permission to see the leaderboard