The central government implements digital currency
As of September 2019, the central bank's digital currency has not been issued
the development history of the central bank's digital currency is as follows
in 2014, the Central Bank of China set up a special research team to conct in-depth research on the framework of digital currency issuance and business operation, key technologies of digital currency, issuance and circulation environment, and legal issues faced
in January 2017, the central bank officially established the digital currency Research Institute in Shenzhen
in September 2018, the Institute of digital currency built a trade finance blockchain platform
On July 8, 2019, at the launching ceremony of the digital finance open research program and the first academic seminar, Wang Xin, director of the Research Bureau of the people's Bank of China, disclosed that the State Council has officially approved the research and development of the central bank's digital currency, and the central bank is engaged in corresponding work in organizing market institutionson August 2, 2019, the central bank said at the second half of 2019 work video conference that it would speed up the research and development of legal digital currency
on August 10, 2019, Mu Changchun, deputy director of the payment and Settlement Department of the central bank, said at the Yichun forum of 40 people of China finance that "the central bank's digital currency can be said to be ready"
on August 18, 2019, the CPC Central Committee and the State Council issued their opinions on supporting Shenzhen to build a leading demonstration zone of socialism with Chinese characteristics, which mentioned supporting innovative applications such as digital currency research in Shenzhen
on August 21, 2019, the official micro blog of the people's Bank of China released two articles on digital currency. One is fan Yifei, vice president of the people's Bank of China, who was published in January 2018, talking about some considerations of digital currency of the people's Bank of China. The other is mu Changchun, deputy director of the Department of payment and settlement, who delivered a speech in Yichun on August 10
extended data:
practical significance
the digitalization of central bank's currency helps to optimize the central bank's monetary payment function, improve the central bank's monetary status and the effectiveness of monetary policy. The central bank's digital currency can become an interest bearing asset to meet the holder's reserve demand for safe assets, and can also become the lower limit of bank deposit interest rate
can also become a new monetary policy tool. At the same time, the central bank can affect the bank's deposit and loan interest rate by adjusting the central bank's digital currency interest rate, and help break the zero interest rate lower limit
operation system
fan Yifei, vice governor of the people's Bank of China, said in the article that the digital currency of the people's Bank of China should adopt a two-tier operation system. This model does not change the relationship between creditor's rights and debt of currency in circulation, does not change the existing money supply system and al account structure, does not constitute a competition for commercial banks' deposit currency, and does not increase commercial banks' dependence on the interbank lending market
will not affect the lending ability of commercial banks, and will not lead to the phenomenon of "financial disintermediation". At the same time, because it does not affect the existing monetary policy transmission mechanism, it will not strengthen the pro cyclical effect under the pressure environment, and it can improve the convenience and security of payment, and it also has the credit advantage of central bank endorsement
Zhou Xiaochuan pointed out that as legal tender, digital currency must be issued by the central bank. The issue, circulation and transaction of digital currency should follow the idea of integration of traditional currency and digital currency, and implement the same principle of management. That is to say, q-coin and the like are definitely not good
as for whether to use blockchain technology to create digital currency. Zhou Xiaochuan said that the blockchain technology is an optional technology, but so far, the blockchain still occupies too many resources. Whether it is computing resources or storage resources, it can't cope with the current transaction scale, and whether it can be solved in the future depends on it. Zhou Xiaochuan said that in addition to blockchain technology, the digital currency research team of the people's Bank of China has also concted in-depth research on other related technologies involved in digital currency, such as mobile payment, trusted and controllable cloud computing, cryptographic algorithm, security chip, etc
in addition, Zhou Xiaochuan also mentioned that there is a lot of discussion about "51% attack" (assuming that indivials have 51% of the computing speed of the whole network, they can realize double payment, reverse transactions, paralyze the whole network, and completely lose the transfer function). More specifically, compared with the special currency, bitcoin does not need the central bank. Zhou Xiaochuan mentioned that for the digital currency controlled by the central bank, a series of technical means, mechanism design and laws and regulations will be adopted to ensure the security of the digital currency operation system, which is different from the design idea of bitcoin from the beginning
as for the digital currency timetable, Zhou Xiaochuan said that there is no established timetable. The relationship between digital currency and cash will be parallel and graally replaced for quite a long time. For reference.
when people are used to digital currency, paper money will graally withdraw from the circulation market and enter the collection field. In the new environment of payment and circulation, the traditional paper money will become a symbol of an era and a memory of people. The paper money that used to circulate in the market will also become a kind of cultural and artistic investment goods, active on the electronic disk of the post money card. And those earlier and even rarer coins will also stimulate their prices to rise in this situation. It can be seen that the central bank's graal promotion of digital currency will have a profound impact on people's living habits and investment and financial management, which is worth looking forward to Sohu)
however, digital currency does not have to be used for payment. Some domestic application-oriented digital currencies have begun to find another shortcut and come out with a different truth. For example, coin Ying China crowdfunding project token; Puyin group launched the tea based digital currency Puyin.
monetary policy, like tax, police, court and other state machines, is the foundation of modern state operation and an important part of state machine. As long as there is no fundamental change in the social organization form of the state, the monetary system based on the national credit will always exist, and bitcoin and other virtual currencies will not become the standard currency of a country. Bitcoin is actually just the use of technology, which is at most an asset, not a real currency< Of course, credit money is prone to inflation. In a sense, people's concern about bitcoin reflects people's worry about inflation under the condition of credit currency. Therefore, central banks should strengthen liquidity management, reasonably regulate money supply and keep prices basically stable.
It is not currently available
at present, the Central Bank of China has not issued and approved the digital currency of issuers and investors
However, at the beginning of the year, the central bank held a seminar on digital currency, at which it made it clear that it was necessary to issue digital currency as soon as possible, and the central bank put the issue of digital currency on the agendahowever, so far, the central bank has not issued any digital currency, and Zhou Xiaochuan, the governor of the central bank, said that the time is not ripe to issue digital currency. Moreover, the digital currency issued by the central bank is different from bitcoin, Ruitai, Laite and other digital cryptocurrencies, and the digital currency issued by the central bank is not decentralized
when the central bank issues digital currency, it needs to establish a basic digital currency system. In this system, the central bank is in charge of the digital currency issuing bank, the commercial bank is in charge of the bank, and the public and indivials hold digital wallets. This is not much different from the existing monetary system in essence, but the managed currency is changed from paper money to digital cryptocurrency
in terms of issuing mechanism, there are two modes:
one is the traditional mode of "central bank commercial bank", that is, the central bank issues digital currency from the issuing bank of the central bank to the Bank of the commercial bank. When an indivial withdraws money from the commercial bank, the digital currency is transferred from the commercial bank to the personal digital wallet
another mode is the "central bank public" mode, that is, the central bank can directly issue digital currency from the currency issuing bank to the digital wallet of the public and indivials. In essence, no matter which issuing mode, money is ultimately held by the public, which is the debt of the central bank to the public
although the issuing method of digital currency is still under study, paper currency has been regarded as "the currency of the previous generation" by some professionals, and it is the general trend to be replaced by new technologies and procts. He Maochun predicted that when the era of digital currency really comes, people will carry less and less cash, travel more and more safe, poverty alleviation more and more accurate, corruption more and more difficult to escape, and thieves more and more difficult to be
on the other hand, the application-oriented digital currency based on the token of coin profit China platform is also emerging.
although the issuing method of digital currency is still under study, paper currency has been regarded as "the currency of the previous generation" by some professionals, and it is the general trend to be replaced by new technologies and procts. He Maochun predicted that when the era of digital currency really comes, people will carry less and less cash, travel more and more safe, poverty alleviation more and more accurate, corruption more and more difficult to escape, and thieves more and more difficult to be
on the other hand, the application-oriented digital currency, which is mainly based on the token in China, is also emerging.
according to the market in 2020, the price of the month center generally ranges from 20000 to 150000 nationwide
the key lies in the city and central hardware facilities. There are many factors that affect the standard price of the center. Generally, the standard price of the center varies with the scale, environment and package
the cost of the confinement center is relatively high, ranging from 40000 to more than 100000. The more luxurious the decoration, the higher the price
in the confinement center, the baby care service is provided. When the puerpera need the care service, the baby can be taken care of by the nurse, so that they can spare time to recover their body and get a good rest
selection method
the number of confinement centers is large, but most mothers don't know much about them, so it's very important to know about them. From an expert's point of view, the services and facilities of confinement centers are definitely more professional than looking for a sister-in-law, but the cost is higher, In fact, many mothers with good family conditions want to choose the confinement center, but they are afraid that it is not worth the money
for the instry of confinement center, experts put forward several good suggestions for mothers to refer to. Choosing the way of confinement should be considered according to their own situation:
first, the family's economic conditions are not good. If the family can take care of themselves and their baby, they can choose to take care of their family. At most, they can hire a nanny and buy more books, Let family members and nannies learn some maternal nutrition meal practices and baby care knowledge. It is not recommended to buy the monthly meal, which has been exposed by most media
Second, the family's economic conditions are general, so it is not recommended that the family take care of them. After all, the quality of confinement is very important to their recovery and their baby. Parents' concept of confinement is somewhat traditional, which is not consistent with young people's opinions, and it is easy to cause conflicts. After multiple interviews, they need to reserve their sister-in-law in advance, but it is more difficult to find a good one, because most of them are from rural areas, Lack of professional knowledge of baby care Third, the family conditions are good, and you can choose to sit in the confinement center. There are more than ten confinement centers in Shanghai, with different positioning. Most of them are invested by indivials, and the service is good and bad, so it is not easy to choose a suitable confinement centerTo calculate the helical gear parameters, you need to know the basic parameters:
normal molus M_ n. Number of teeth Z, normal pressure angle α_ n. Helix angle β
generally, the crown height coefficient h * is 1, and the root height coefficient C * is 0.25. If there is displacement, it is necessary to calculate the displacement: x
the following is the basic parameter
end face molus: M_ t=m_ n/cos β
Calculation formula of pressure angle at the end face: Tan α_ t)=tan ( α_ t)/cos( β)diameter of dividing circle: D = m_ n × z/cos( β)
addenm circle diameter: no displacement: Da = D + 2 × m_ n × H * with displacement: Da = D + 2 × m_ n × H * + x)
root circle diameter: no displacement: DF = D-2 × m_ n ×( H * + C *) with displacement: DF = D-2 × m_ n ×( H * + C * - x)
diameter of base circle: DB = D × cos α_ t)
in addition, there are more important dimensions, such as normal pitch, end pitch, etc., which can be obtained by referring to relevant manuals
Extended data:
judgment of helix rotation direction: first, we make the gear axis vertical, if the right height of helix is right rotation; On the contrary, the height on the left side of the helix is left-handed
end face and normal surface parameters:
end face: the plane perpendicular to the gear axis, and the parameters on the end face are generally added with subscript t
normal plane: the plane perpendicular to the helix, and the parameters on the normal plane are generally subscript n
(1) pitch and molus: = t= π
(2) pressure angle: generally, the parameters in normal plane are standard parameters
The correct meshing condition: the helix angle must be equal in size and opposite in direction. The normal molus m is equal to the normal pressure angleB. geometric dimension calculation: in calculation, the calculation formula of spur gear can be directly applied to the end face of helical gear because a pair of helical gear transmission is equivalent to a pair of spur gear transmission on the end plane
there are many kinds of gear transmission, among which the efficiency of helical gear is very high, for example, the efficiency of spur gear transmission is lower than that of helical gear transmission
Like spur gear mechanism, helical gear can be used to improve the load capacity of transmission by recing the center distance a, which can be used for high-speed operation. Helical gear recer is a new type of recer. The helical gear recer is small in volume, light in weight and good in economy Advantages:(1) good meshing performance: the meshing process between helical cylindrical gears is an excessive process, and the force on the teeth is graally from small to large, and then from large to small; Helical gear is suitable for high speed and heavy load
(2) large coincidence degree: the increase of coincidence degree can improve the bearing capacity of gear. So the life of the gear is prolonged. The coincidence degree mainly depends on the meshing time, while the long meshing time and large contact area of helical gear rece the stress. The transmission is stable and the economy is increased
(3) compact structure: the less the minimum number of teeth, the more compact the structure