What does blockchain mapping mean
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, which is used to verify the effectiveness of its information (anti-counterfeiting) and generate the next block
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in a sequential way according to the time sequence, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, and uses cryptography to ensure the security of data transmission and access It is a new distributed infrastructure and computing method to program and operate data by using intelligent contract composed of automated script code
extended data:
the evolution mode of blockchain is as follows:
& 9642; Blockchain 1.0 - digital currency
▪ Blockchain 2.0 - digital assets and smart contracts
▪ Blockchain 3.0 - Implementation of distributed applications in various instries
blockchain features:
1. Disintermediation. Due to the use of Distributed Accounting and storage, there is no centralized hardware or management organization in the system, the rights and obligations of any node are equal, and the data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system
2. Openness. The system is open. In addition to the private information of all parties to the transaction is encrypted, the data of the blockchain is open to all. Anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
3. Autonomy. Blockchain adopts consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work
The information can not be tampered with. Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid. Therefore, the data stability and reliability of the blockchain are extremely high5. Anonymity. Because the exchange between nodes follows a fixed algorithm, the data interaction does not need to be trusted (the program rules in the blockchain will judge whether the activity is effective). Therefore, the counterparties do not need to make the other party trust themselves by disclosing their identities, which is very helpful for the accumulation of credit
decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain
openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention
A: the basic characteristics of blockchain
I. decentralization
blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage
the foundation of blockchain technology is open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
Third, independencebased on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention
Four, safetyas long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily controlled and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes
5. Anonymityunless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information transmission can be anonymous
Deflection refers to the linear displacement of the axis of the member perpendicular to the axis or the central plane of the shell perpendicular to the central plane when the force or non-uniform temperature changes
the deflection of slender body (such as beam or column) refers to the displacement of each point on its axis in the normal plane of the axis at that point. The deflection of thin plate or shell refers to the displacement of each point on the middle plane normal at this point. The rule that the deflection of each point on the object changes with position and time is called deflection function or displacement function
the deflection observation of building includes the deflection observation of building foundation, building main body and independent structure (such as independent wall and column). For high-rise buildings, when there is a large concentrated load on a small area, it may lead to the settlement of the foundation and buildings. The uneven settlement will lead to the inclination of the building, the bending of local components and the generation of cracks
extended data
1. Deflection calculation formula: ymax = 5ql ^ 4 / (384ei) (EI is the bending stiffness of beam under uniform load q)
deflection is related to load size, member section size and material physical properties of member
Deflection the linear displacement of the centroid of the cross section along the direction perpendicular to the axis ring bending deformation is called deflection γ Expressionrotation angle the angle at which the cross section turns relative to its original position ring bending deformation is called rotation angle θ Expression
The traditional bridge deflection measurement mostly uses dial indicator or displacement meter to measure directly, which is still widely used in bridge maintenance, old bridge safety assessment or new bridge acceptancein today's mobile payment era, few people will use coins for payment . A lot of people, they think that mobile payment is more convenient, if you carry RMB, it will be very troublesome, so now less and less people use paper money to pay. In fact, the process of making paper money is also very complicated. The materials used to make coins are different metals. Compared with those rare metals, low-cost metals are more suitable for making coins
< / blockquote >and those rare metals, such as gold or silver, are suitable for making commemorative coins with collection value . In many countries, some of their currencies are made of alloy, because it is a very ideal material for coinage, and the hardness is improved by mixing with other metals. At the beginning of making coins, we should choose the materials and put the selected metals in the furnace for casting and melting. After many times of rolling in the rolling workshop, the thickness of the coin can meet the requirements of coins, and it can be made into semi-finished procts for further processing{ RRRRR}
with the progress of science and technology, now many mold making machines have become engraving machines for casting to replace the previous manual process . It can improve the accuracy to a certain extent. It used to take a whole day to manufacture, but now it can complete the remanufacturing of the mold within a few hours. After that, it can be pressed on the coin, and the coin will become the currency in circulation