Take Mrs Yifang lightning power network as an example
There is an essential difference between Ethereum and bitcoin. What is the difference? Bitcoin defines a set of currency system, while Ethereum focuses on building a main chain (which can be understood as a road) to allow a large number of blockchain applications to run on this road
from this point of view, Ethereum's application scenarios are more extensive, which is why we say that Ethereum marks a simple monetary system in the era of blockchain
1.0, and a transformation to other instries and application scenarios in the era of blockchain 2.0
however, there is no perfect thing in the world. Although Ethereum has expanded the application scope of blockchain in all walks of life and improved the speed of transaction processing, it also has some disputes and doubts
first, the solution to the lack of scalability of Ethereum: slicing technology and lightning network
the bottom design of Ethereum, the biggest problem is that Ethereum has only one chain and no side chain, which means that all programs have to run on this chain equally, consuming resources and causing system congestion. Just like last year's very popular Ethereum game "encryption cat", when this game was very popular, it once caused Ethereum network paralysis
to improve the processing capacity, Ethereum proposes two ways: shard and lightning network. Let's introce these two technologies respectively
(1) fragmentation technology
vitalik buterin, founder of Ethereum, believes that the reason why mainstream blockchain networks such as bitcoin process transactions very slowly is that every miner has to process every transaction in the whole network, which is actually very inefficient. The idea of fragmentation technology is: a transaction does not need to be processed by all nodes in the whole network, as long as some nodes (miners) in the network are allowed to process it. Therefore, Ethereum network is divided into many pieces. At the same time, each piece can handle different transactions. In this way, the network performance will be greatly improved
however, the slicing technology is also controversial. As we all know, the important idea of blockchain technology is decentralization. Only when the whole network witnesses (processes) the same transaction can it have the highest authority. The Ethereum slicing technology is similar to the group witness, not all nodes witness together. In this way, it will lose the absolute "decentralization" attribute, and can only achieve the purpose of high performance by sacrificing certain characteristics of decentralization
(2) lightning network
lightning network uses the way of transaction under the chain. What does that mean? It means: when the participants of lightning network transfer money to each other, they do not need to confirm the transaction through the main chain of Ethereum, but create a payment channel between the participants and complete it under the chain
however, lightning network is not separated from the main chain. Before establishing a payment channel, you need to use the assets on the main chain as collateral to generate a balance proof, which indicates that you can transfer the corresponding balance. In the case that both parties of the transaction hold the balance certificate, both parties can make unlimited number of transfers under the chain through the payment channel
only when the off chain transaction is completed and the assets need to be transferred back to the chain, the balance change information of the main chain account will be registered on the Ethereum main chain, and no matter how many transactions occur ring this period, there will be no record on the main chain
another real benefit of lightning network is that it can save the cost of miners for you. At present, when we trade on the main chain of Ethereum, we need to consume gas and pay for miners. Once we move the transaction to the lower chain, we can save this part of the cost
Of course, lightning network is not perfect. When using the lightning network, the assets on the main chain should be used as collateral; And this part of assets as collateral can not be used before the user completes the transaction under the chain. This also determines that lightning trading is only suitable for small transactionsthe above is the problem of insufficient scalability of Ethereum, as well as the two main solutions: fragmentation technology and lightning network
Second, there are loopholes in Ethereum's smart contract and the infamous Dao event
Ethereum's smart contract is very powerful, but there are loopholes in any code. The biggest controversy of Ethereum's smart contract lies in the so-called loopholes, that is, security issues. According to relevant research, 34200 (about 3%) of the nearly 1 million smart contracts based on Ethereum contain security vulnerabilities, which will allow hackers to steal eth, freeze assets or delete contracts, such as the infamous Dao incident
(1) what does Dao meanbefore introcing the Dao event, let's first introce what Dao is. Dao is the abbreviation of decentralized
autonomous organization, which can be understood as decentralized autonomous organization. From the perspective of Ethereum, Dao is a kind of contract or a combination of contracts on the blockchain, which is used to replace the government's review and complex intermediate proceres, so as to achieve an efficient and decentralized trust system. Therefore, Dao is not a specific organization, that is to say, there can be many Dao, all kinds of Dao
(2) the infamous Dao event
however, when we talk about Dao now, we basically refer to the Dao event, that is, the infamous hacker attack event we just mentioned. As we know, the English word "the" refers to "the Dao event". The Dao event
refers to "the Dao event", because we just said that Dao is not a specific organization, there can be many Dao, all kinds of Dao
in 2016, slock.it, a German company focusing on "smart locks", launched the Dao project on Ethereum in order to realize decentralized physical exchange (such as apartments and ships). Since April 30, 2016, the financing window has been open for 28 days
unexpectedly, this Dao project is very popular. It raised more than US $100 million in just half a month. By the end of the whole financing period, it raised a total of US $150 million. Therefore, it has become the largest crowdfunding project in history. However, it didn't last long. In June, hackers took advantage of the loopholes in the smart contract to successfully transfer more than 3.6 million Ethernet coins and put them into a Dao sub organization, which has the same structure as the Dao. At that time, the price of Ethernet currency fell directly from more than $20 to less than $13
this event shows that there are loopholes in smart contracts, and once the loopholes are exploited by hackers, the consequences will be very serious. This is why many people criticize Ethereum and say that its smart contract is not smart
to solve this problem, many foreign companies begin to provide code audit services in order to solve the vulnerability problem of smart contract. From a technical point of view, some teams are currently testing smart contracts. Most of these teams are led by professors from Harvard, Stanford and Yale, and some of them have obtained investment from leading institutions
in addition to the problems of insufficient expansibility and loopholes in smart contracts, the controversy over Ethereum lies in the POS consensus mechanism it pursues, that is, the proof of equity mechanism. Under the proof of equity mechanism, if anyone holds more money and holds it for a longer time, he will get more "rights" (interests) and have the opportunity to get bookkeeping power, Bookkeeping can also be rewarded. In this way, it is easy to create the oligarchic advantage of "the stronger the stronger"
Another problem is the chaos of ICO. ICO is a common way to raise funds for blockchain projects, which we can understand as pre-sale. The outbreak of ICO projects on Ethereum has caused illegal activities such as fund allocation and money fraud under the banner of ICO, which has caused security risks to social and financial stabilityIt's Jian'an No.1 bus line: Metro Line 11 → Metro Line 1 → m235, about 30.8 km
1. Walk about 10 meters from Shajing station to Shajing station
2. Take Metro Line 11, pass 9 stations to Qianhaiwan station
< P > 3. Walk about 210 meters to transfer to Metro Line 14. Take Metro Line 1, pass 1 station to Xin'an station
5 Walk about 190 meters to Xin'an subway station
6, take m235 bus, pass 3 stops to Bao'an sub branch station of CCB
7, walk about 50 meters to China Construction Bank (Shenzhen Bao'an sub branch) (No.68 Jian'an 1st Road)
first, it can be divided into big environment and small environment
A. general environment. Where is this place located in the country or city? What cities or buildings are there around? How about economy, culture and transportation What was, is and will be
B. small environment. What are the buildings inside or around this place? It can be discussed from cultural and ecational buildings, entertainment buildings and office buildings. Greening is indispensable
secondly, it can be divided into two details: why the place or building has a positive impression on people, or why people choose this place
a. the design of this place conforms to the human body
B. description of the color space of this place.
First: preparation for the early stage of the annual meeting. Review the gains and losses of each link in the preparation, affirm and accumulate the good points, and summarize the shortcomings< Second, the implementation of the annual meeting. The review of all aspects of the implementation of the annual meeting, the series and highlights of the process
Third, the coordination of the annual meeting. The general annual meeting is a multi department collaborative work, reflecting a team work, and reviewing the outstanding department cooperation.
to check whether the school's network exit restricts the network such as Xbox, try this account with other notebooks.
In September 2001, the China International Science and Technology Exhibition Center, with a total construction area of 120000 square meters, was officially opened
the magnificent architectural style and unique architectural charm of China International Science and technology exhibition center make it an indisputable landmark in northern Beijing. Its completion marks the first large-scale, high-end and multi-functional business center integrating 5A intelligent office building, high-end hotel type business apartment, advanced exhibition hall, international standard multi-functional conference hall, revolving coffee shop and various catering and entertainment facilities in North Beijing
China International Science and Technology Exhibition Center is divided into three blocks a, B and C
block a and block B are 5A grade intelligent office buildings with a total construction area of 56000 square meters. With Beijing's leading intelligent configuration and high-end decoration, they can provide customers with comprehensive business services and superior information service environment
the 5-21 floors of Block C are Exhibition Hotel Apartments with a total construction area of 21100 square meters, which are composed of 166 apartments with different layout and decoration styles. Exhibition Hotel Apartment is a high-end hotel business apartment, with business suites and luxury suites
the exhibition hall is on the 1st and 2nd floors of block B of China International Science and Technology Exhibition Center, with an exhibition area of 9300 square meters. The exhibition hall on the first floor covers an area of 5700 square meters and is divided into two exhibition areas a and B. The exhibition hall on the second floor is 3600 square meters. The exhibition hall mainly holds various high-grade international and domestic high-tech proct exhibitions, science and technology, information, culture and art exhibitions, highlighting the theme of science and technology and emphasizing cultural taste
the conference hall of China International Science and Technology Exhibition Center is located on the 3rd, 4th and 15th floors of block B, with a total area of 5000 square meters. It consists of 10-400 square meters of conference rooms, multi-function halls and negotiation rooms that can accommodate 5-400 people
on the 23rd floor of Block C of China International Science and Technology Exhibition Center is a unique revolving restaurant in North Beijing. It is equipped with fully enclosed floor to ceiling windows, with a construction area of more than 500 square meters. It rotates at the speed of 90-120 minutes per circle, allowing diners to overlook the whole area of North Beijing, including Deshengmen, Asian Games Village, Olympic Village under construction and Zhongguan Village
Chaoyue cuisine restaurant is set on the 15th floor of block B of China International Science and Technology Exhibition Center. Shark fin and abalone are the special delicacies here, which can provide customers with pure Hong Kong cuisine. The staff restaurant is convenient for office customers to eat, and the fast food restaurant can provide a variety of delicious fast food for exhibitors and visitors. Xinle bar in the southeast corner of China International Science and Technology Exhibition Center will bring customers unique experience and fun with its fashionable and romantic atmosphere. With all kinds of facilities and considerate service, there are more than 100 kinds of foreign wine, red wine, beer, cocktails and all kinds of drinks and snacks. It is an ideal place for friends gathering and entertainment
the Convention and Exhibition Center building has two floors of parking lots, which can provide more than 500 parking spaces for customers and exhibitors
