Blockchain framework design

2. Baite is not recommended

to practice guitar: most of them are basswood panels, some even basswood back panels, which are less than 300 yuan, also known as firesticks (because they are made of the same material as firewood, and the intonation is poor)
entry guitar: most of them are spruce panels, rosewood finger boards, and the back panels are not necessarily. The price is about 1000 yuan, and most of them are 500 yuan or 600 yuan, About 1000 yuan, there are also some elementary Miandan Qin
medium Guitar: most of them are spruce panel, rosewood fingerboard, back side panel, mahogany and fire rosewood. Generally, they are middle end single piano of various series, and some of them are full single (very few), with the price around 3000
high end: all single guitars and spruce veneers are the most popular. The price is four or five thousand or more. There is no upper limit. There are tens of thousands of them, but most people don't need them

tips on guitar selection: http://www.jitatang.com/guitar It is recommended to refer to

no matter where you buy it, you should know some experience to avoid being trapped. Generally, you will be trapped when you go to a piano shop for the first time. The most important two points (you can't hear the timbre and so on):
1. Look at the appearance and choose the log color or black directly Sunset color (the classic three color system), never white, Pink Guitar, that is the above said practice piano grade
2. Check the handle. When the guitar is tuned to the standard pitch, the distance between the string and the fingerboard should be about 3mm (that is, the thickness of a coin) at the 12th point. If you press the string too high, you will feel tired, otherwise it will cause the phenomenon of playing. A good hand feeling is that you can easily press any tone with your left finger without any proct or noise, and you don't feel any effort when you press it horizontally
3. Performance (in fact, you can't see it. You can get what you pay for. It's right to choose the most expensive one in your budget.)

3. Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Jinwowo Group believes that it is composed of data layer, network layer, consensus layer, incentive layer, contract layer and application layer:
1. Data layer: encapsulates the underlying data block and related data encryption and timestamp technologies
2. Network layer: it includes distributed networking mechanism, data dissemination mechanism and data verification mechanism
3. Consensus layer: it mainly encapsulates various consensus algorithms of network nodes
4. Contract layer: it mainly encapsulates all kinds of scripts, algorithms and smart contracts, which is the basis of the programmable characteristics of blockchain
5. Application layer: encapsulates various application scenarios and cases of blockchain.

4. Aggregation chain refers to the innovative introction of "alliance chain + cross chain + public chain" aggregation chain technology architecture on the basis of long-term accumulated alliance chain technology, so as to realize the efficient, safe and low-cost flow of data and assets, and then practice the historical mission of enabling distributed economy.

5. The three levels of jinwowo analysis blockchain technology are as follows:
protocol layer
the so-called protocol layer refers to the lowest level technology. This level is usually a complete blockchain proct, similar to the operating system of our computer. It maintains network nodes and only provides API for calling. Usually, the government will provide a simple client (commonly known as wallet). The function of this client wallet is also very simple. It can only establish address, verify signature, transfer payment, check balance, etc
extension layer
this layer is similar to the computer driver, which is to make blockchain procts more practical
application layer
this layer is similar to all kinds of software programs in computers. It is a proct that ordinary people can really use directly, and it can also be understood as the browser of B / S architecture procts. The application of this level is almost blank at present.

6. This Canon laser printer icmf426dw features many functions, such as: multiple function, high-speed double-sided printing function, deformation correction function, etc. I know so much, I hope I can help you!

7. Many projects belong to the new infrastructure category. Just take the procts and solutions launched by lierda group as an example: (information communication, 5g and other infrastructure network construction) lierda lorawan solution has low power consumption, strong anti-interference, low cost and high capacity; Lilda NB IOT solution has wide signal coverage, strong penetration ability, ultra-low power consumption, ultra-high sensitivity, strong anti-interference and low cost Smart city, municipal pipe network) has a mature underground parking energy-saving lighting system to rece lighting costs, system rability and reliability, save maintenance costs, improve management efficiency Artificial intelligence) Intelligent Hotel solutions meet the personalized needs of customers and make the hotel management service more efficient and orderly

8. Firstly, we need to know that blockchain is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism and encryption algorithm. Secondly, as for the composition architecture of blockchain system, jinwowo Group believes that it is composed of data layer, network layer, consensus layer, incentive layer, contract layer and application layer

1. Data layer: encapsulates the underlying data block and related data encryption and timestamp technologies

2. Network layer: includes distributed networking mechanism, data propagation mechanism and data verification mechanism

3. Consensus layer: it mainly encapsulates various consensus algorithms of network nodes; The incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives

4. Contract layer: it mainly encapsulates all kinds of scripts, algorithms and smart contracts, which is the basis of the programmable characteristics of blockchain; At present, jinwowo in Southwest China has taken the lead in big data research with blockchain as the underlying technology, and also provides big data services with blockchain as the underlying technology

5. Application layer: encapsulates various application scenarios and cases of blockchain. In this model, chain block structure based on timestamp, consensus mechanism of distributed nodes, economic incentive based on consensus computing power and flexible and programmable smart contract are the most representative innovations of blockchain technology

9. The current mainstream blockchain architecture includes six layers: network layer, data layer, consensus layer, incentive layer, contract layer and application layer. The positions of data layer and network layer are exchanged in the figure, and the main uses will be described in the next section
network layer: blockchain network is essentially a P2P (peer-to-peer) network. The resources and services in the network are distributed on all nodes, and the information transmission and service implementation are directly carried out between nodes, without the intervention of intermediate links and servers. Each node not only receives information, but also generates information. Nodes synchronize information by maintaining a common blockchain. When a node creates a new block, it notifies other nodes in the form of broadcast. After receiving the information, other nodes verify the block and create a new block on the basis of the block, So as to achieve the role of the whole network to jointly maintain a bottom ledger. Therefore, the network layer will involve the design of P2P network, propagation mechanism and verification mechanism. Obviously, these designs can affect the confirmation speed of block information. The network layer can be used as a research direction in the scalable scheme of blockchain technology
data layer: the underlying data of blockchain is a data structure of block + linked list, which includes data block, chain structure, timestamp, hash function, Merkle tree, asymmetric encryption, etc. Among them, data block and chain structure can be used as the improvement direction of data layer research in the extensible scheme of blockchain technology
consensus layer: it is the basis for highly dispersed nodes to reach a fast consensus on the effectiveness of block data. The main consensus mechanisms include pow (proof of work), POS (proof of stake), dpos (delegated proof of stake) and pbft (Practical Byzantine fault tolerance), They have always been the highlight of the scalable solution of blockchain technology
incentive layer: it is a common mining mechanism, which is used to design certain economic incentive model and encourage nodes to participate in the security verification of blockchain, including the design of issuance mechanism and allocation mechanism. Improvements at this level do not seem to be directly related to blockchain scalability
Contract layer: mainly refers to various script codes, algorithm mechanisms and smart contracts. Strictly speaking, this layer of the first generation blockchain is missing, so they can only trade, and can not be used in other fields or other logical processing. The emergence of the contract layer makes it a reality to use blockchain in other fields. This part of Ethereum includes EVM (Ethereum virtual machine) and smart contract. The improvement of this level seems to provide a potential new direction for the scalability of the blockchain, but it does not seem to be directly related to the application layer in terms of structure
it is the display layer of the blockchain, including various application scenarios and cases. For example, Ethereum uses truffle and Web3 JS. The application layer of blockchain can be mobile terminal, Web terminal, or integrated into the existing server, taking the current business server as the application layer. The improvement of this level also seems to provide a potential new direction for the expansion of blockchain, but structurally, it doesn't seem to be directly related
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.

10.

Shanghai Metro uses metropolises to brush in and then goes out without brushing. It should be reported to the staff in time

passengers who use mobile phones to "brush the code to pass through the gate" can timely report to the staff if they find any abnormal conditions ring the passage

according to the relevant provisions of Shanghai Rail Transit Management Regulations:

Article 30 passengers shall take the train with valid tickets, and passengers who cross the station shall pay the excess part of the fare

if passengers have no tickets or hold invalid tickets, the rail transit enterprises can make up the fare according to the highest one-way ticket price of the rail transit network, and can add five times the fare. The municipal traffic administrative department shall strengthen the supervision over the fare increase of rail transit enterprises

passengers who enjoy the travel discount should hold their own valid certificates. Passengers are not allowed to use other people's certificates or forged certificates

if the passenger has the behavior of using other people's certificates, using forged certificates to take the bus, or other acts of ticket evasion, the relevant information can be incorporated into the personal credit information system

extended data

passengers should consciously abide by the service instructions of rail transit enterprises on ticketing, safety and other aspects, accept and cooperate with safety inspection, follow the tips for service and emergency facilities, and obey the management of rail transit staff. In case of any dispute, it may be reported to the rail transit enterprise, but it shall not affect the management of the rail transit staff and the normal operation of the rail transit

for those who enter the station or take the train, the following behaviors are prohibited:

1. Stop the train

2. Unauthorized access to track, tunnel and other prohibited areas

3. Climbing or crossing the fence, fence, railing and gate

4

5. Smoking, spitting, defecating, spitting gum resie, littering paper and other debris

6. Scribble, depict or post without permission

Setting up stalls, parking vehicles, piling up sundries, performing arts, distributing publicity materials or engaging in sales activities without authorization

8, begging, lying down, collecting waste goods

9. Carry live poultry, cats, dogs (except guide dogs) and other pets

10. Carrying bicycles (including folding bicycles)

11. Carrying inflammable, explosive, toxic, radioactive, corrosive and other dangerous goods that may endanger personal and property safety

12. Carrying fragile and sharp articles with serious odor and without safety packaging

13. Use skateboard and skates

14. Use emergency or safety devices in non emergency state