Domestic miner
At the end of March this year, bitmainland launched an ant miner X3 based on ASIC, which is mainly aimed at Monroe coin (XmR) and cryptonight algorithm dependent cryptocurrency. Monroe coin immediately issued a counter statement that it will change the core algorithm to fight against the invasion of ASIC computing power
what would be the result if it appeared in the world of digital cryptocurrency? That is, the wrong calculation results may be brought into the whole network without being discovered
More importantly, if a "calculator manufacturer" monopolizes the calculator market, it can also deliberately proce this kind of calculator with errors to change the mathematical rulesafter all, the "calculation" in the field of crypto digital currency is not as simple as 1 + 2 + 3. You can't compare paper currency with special currency by hand
the practical significance of computing power monopoly in mainland China
we have learned about attacks based on 51% computing power in various articles
but the reality is that although the global power of 78% was in Chinese mainland, fortunately, they were scattered in different pools and controlled by different people. p>
although all POW based cryptocurrencies have the risk of being attacked by 51%, few people can really launch attacks e to the dispersion of computing power
but what if the miners themselves don't want to attack, but the mining machinery manufacturers attack
still using the analogy just now, although each miner subjectively wants to do the problem checking independently, their calculator is manipulated remotely and gives consistent wrong answers. This may pose a great threat to digital cryptocurrency
however, the manufacturer with the absolute voice of mining machinery had such a problem in mainland China
in April 2017, the back door of antbled came out. Although this is described as a "vulnerability" in Chinese, antbled is more like a function that has been implemented and designed
anonymous people found that after an ant miner made by bitmainland was connected to the network, it would communicate with a domain name held by bitmainland on a regular basis and return the miner's serial number, MAC address and IP address to bitmainland's server. If the server of bitcontinent gives a negative signal, the miner will stop running
although bitcontinental responded that they could not shut down any mining machines that did not belong to them. However, the bitcoin core team has proved in experiments that this function has no verification. Anyone can shut down mining machines by forging DNS - but it also means that bitcoin mainland has the ability to shut down any sold mining machines
After, bitcontinent fixed this "loophole", but it caused heated discussion in the community. This has also set the tone that almost all pow blockchain communities are biased against mainland China
a few months later, under the leadership of bitcontinent, viabtc g out the first block and made a hard bifurcation with the blockchain of bitcoin. From then on, bitcoin BCH (bitcoin cash) appeared in the world
will the monopoly of mining machinery destroy the distributed system
facing this problem, we should have a clear answer now. That is, the monopoly of mining machinery will certainly affect the safe operation of pow digital cryptocurrency
the problem is not whether bitcontinental and its founder Wu Jihan are trustworthy, but that one of the values of any blockchain system is to operate safely without trust in any single company or indivial
even if the ASIC miner is not monopolized by bitmainland, the ASIC miner itself will increase the concentration of computing power
the ASIC used for mining has great requirements for ventilation, power and site, and has no use except for mining. At the same time, the calculation difficulty of the whole network is increased e to the powerful computing power
as a result, it is very difficult for external players to start mining in the next software on the computer as they did five years ago. And the recent centralized exchange is caused by frequent black incidents, which also proves that concentration in this unregulated market will definitely lead to insecurity
assuming that the bitcoin network runs on top of one million miners, no one can shut it down. And if the bitcoin network runs on 20 large mines, it's much easier to shut it down
and by the end of 2017, 78% of the effort was concentrated in mainland China, which led to a real possibility of Chinese mainland regulators' launching a deadly attack against the special currency. p>
moreover, most of the scenarios of using digital cryptocurrency are related to "decentralization". Once centralized, it means that these scenarios no longer exist. It turns a project that might have value into a pure waste of computing power
Then, what measures should we take in the face of this situationfirst of all, as the project side, it may be time to give up the pure POW mechanism. In fact, in many projects of issuing cryptocurrency, especially in asset securitization projects. Similar to the concept of stock in the real world, POS itself is more reasonable than pow
in the media that don't know about blockchain, we often hear such words as "bitcoin wastes a lot of computing power and has no value", which is reasonable to some extent. It is difficult for a POW based blockchain to bind the value of the project itself to the issued digital cryptocurrency - because the real value behind the price of the currency does not come from the project, but from the cost of maintaining computing power
and the hybrid mode of pow + POS is more like the future. In the hybrid mode, both coin holders and miners can participate in the major decisions of this community. If a decision is widely accepted, the blockchain will be soft forked to the latest state without excessive intervention of developers, and there will be almost no private resistance of miners or mining machines
secondly, as a retail miner, if you are still digging a pure POW mechanism currency, you should unconditionally support the bifurcation activities initiated by the community to resist the ASIC mining machine, even if it will lead to the failure of your mining machine
this may sound contradictory, but in the long run, it is better to promote the reform of the community and get more benefits in a currency controlled by the monopoly of computing power. Because in many conflicts between computing power and community in the past, the ultimate result is that the computing power owner will forcibly keep the old algorithm to hard fork the blockchain
just like Eth and etc, the classic Ethereum (etc), which belongs to the computing power master, has lost the support of developers and become an air coin with no vitality and impossible to develop applications
as a retail leek, you should be careful to trade the non mainstream digital currencies (except bitcoin) supported by bitmainland mining machinery, so as to avoid falling into a blockchain in which bitmainland controls the computing power completely
finally, if you are bitcontinent, what should you do
bitcontinent's goal is to become Intel, AMD and NVIDIA, make greater contributions to the whole computer instry, and become a great company, not just entangled in the immediate interests of mining
Wall Street financiers have long seen through the violence brought about by NVIDIA's video card mining. The rise and fall of the company's stock price has been consistent with the price of bitcoin, and even affected by the digital currency market. Citron, a well-known short seller, has recently been bearish on NVIDIA, arguing that the company has focused too much on providing services for digital currency miners rather than on serious businesses such as artificial intelligence, games and driverless driving
the mission of chip manufacturers is to provide more powerful chips to drive more intelligent services, and finally contribute to the real world, rather than become monopoly tycoons in the virtual world. When we no longer enter the gate of the virtual world, the only thing left is a deserted land
in an interview with US media last year, Wu Jihan disclosed that he would make an IPO with a market value of billions of dollars. As a company about to go public, bitmainland should not only be responsible to investors, but also accept investors' questions about the sustainability of its business. "If your mining machinery goes public, it will encounter a fork, what should you do?"
and this question, which needs to be asked after the listing, has already appeared: the current price of the split coin xmo after the Monroe team split is $7.50, while the current price of the real Monroe coin XmR is $194, and the split coin is completely abandoned by the Monroe community
before bitcontinent becomes the name of all blockchain communities, we can rely on the huge amount of capital accumulated in recent years to transform into an artificial intelligence chip company along the previous plan, rather than continue to develop a variety of digital currency mining machines to extract the last drop of oil before the ecological collapse
content source: phoenix.com
remember to adopt it
I'm a blockchain developer. Here's a popular answer:
the main features of blockchain technology are decentralization, asymmetric encryption, intelligent contract, etc., which have no central server and can't be tampered with
in the instry, we generally define bitcoin as blockchain 1.0 and Ethereum technology as blockchain 2.0. Compared with blockchain 1.0, Ethereum's biggest advantage is to add the concept of smart contract. Therefore, we can see that the real significance of blockchain is to solve the social credit problem, or the Byzantine general problem (specific network search Byzantine problem )
the traditional Internet data are stored in the company's server, which can be modified, falsified and lost at any time. No matter how authoritative and secure the organization or enterprise is, the correctness and uniqueness of the data can not be guaranteed. So the blockchain technology is the whole chain node synchronization data, each user is a data node, a single user in the case of no secret key broadcast data modification, the whole chain node does not agree, then automatically restore the original data
so in short, the prospect of blockchain is mainly focused on solving the social credit system, finance, securities, asset authentication and other business
I only look for a manufacturing company called Zhengzhou Xinhai machinery in Zhengzhou, which has 40 years of experience in this instry
no matter the technical level, proct perfection, proct quality, company scale or after-sales service are not selected
you can verify it yourself
if it is really good, you should give me extra points, Not much, five is enough
hehe
It has been 150 years since the first jawbone machine appeared in 1858. The jawbone machine is widely used in many fields because of its simple structure, reliable performance, easy operation, convenient maintenance and strong adaptability. Jinjiawu gold ore dressing plant of Jiangxi Tianbao mining company was built in 2005. The designed capacity is 1000 tons per day. The crushing system adopts three stages and one closed circuit process. C80 jaw crusher is used for coarse crushing and pex-250 proced by a famous enterprise in Shanghai is used for medium crushing × Gp100 cone crusher is used for fine crushing. Both coarse and fine crushing are proced by Nordberg C series and GP series
there are many kinds of c-series jawbone machines, including 12 kinds, with specifications ranging from C63 to c3055; Equipped with motor from 45KW to 400KW; The feed size ranges from 350mm to 1200mm; The weight of the equipment also ranges from 6 tons to 23 tons. C series is suitable for coarse crushing operation. As shown in Figure 1
2.2 after assembling
the bolts of the bearing seat of the frame are tightened, there are plates to weld the bolts together in pairs. Matching marks have been made on the frame, connecting screw, middle plate and side plate, which will not cause reverse installation. Specific value of torque is provided for each pre tightening nut
if it is a large machine, when it needs to adjust the discharge port by hydraulic pressure, the specific values of electrical circuit, selection of hydraulic oil and pressure of accumulator are provided
similarly, when assembling the flywheel, each head key has a matching mark with a flywheel and an eccentric shaft, there is no clearance between the flywheel and the eccentric shaft and the bearing labyrinth of the frame, the flywheel is cast with the unique number of the equipment, and the three bolts on the flywheel cover are directly welded together with a flat plate. If there is any looseness ring use, the welded flat plate will break, The operator can judge the shutdown based on this, which will not cause accidents
2.3.1 the adjustment of discharge port is completed by moving two wedges (close or far away), as shown in Figure 2. This movement will effectively change the thickness "s" of the wedge pair, thus increasing or recing the discharge port of the crusher. The device is composed of wedge block (1), nut (2) and locking pipe (3). It is convenient and quick to adjust the discharge port, unlike the domestic equipment which can be adjusted by adding a plug board
when changing the size of the discharge port, loosen the tension bar and the bottom spring nut, as shown in Figure 3, and then turn the nut clockwise or counterclockwise to increase or decrease the discharge port of the crusher. The net effect of a complete rotation of a nut on the discharge of crusher is 2.3mm, taking C80 as an example. Both the discharge port and nut of crusher are provided with nameplate to inform the net effect of each rotation. Turn the two nuts in the same relative direction for a complete circle, the change value of the crusher discharge port will be twice of the value shown
example: change the discharge port of C80 crusher to 10 mm, and the amount of nut rotation is as follows: 10 (mm) ÷ 2.3 (mm / turn) = 4.35 ≈ 4 turns (two turns for each nut). Like the domestic jawbone machine, C80 also needs to loosen or tighten the spring when adjusting the discharge port. The difference is that the latter has a nameplate mark at the spring, and specifies the working length of the spring. For example, C80 indicates that the length of the tension spring is 310mm when it works normally, and a protective plate is set at the tail of the spring to prevent the nut from loosening and the spring from popping out ring the operation of the machine
2.3.2 rib plate
the rib plate thickness of domestic jawbone can reach 55mm, and one rib plate is often more than 100kg; The thickness of C80 rib is only 16mm, the area is smaller and the width is similar. It's much more convenient to replace. From the operation point of view, once the domestic machine enters the ironware, the rib plate will break, while for the C series machine, the rib plate will break after elastic bending. In practice, on April 5 and May 4, 2006, a 16 pound hammer entered the coarse ore bin twice, but it was not found. When it entered C80, the rib plate did not break. Instead, it tilted and bent at an angle, allowing the heavy hammer to break normally after the hammer was discharged. At that time, it was found that the rib plate was in good condition and the bearing was not damaged
2.4 appearance
C series crusher and domestic jaw crusher of the same specification www.sbmepj.com In comparison, the weight is much lighter, the external size is small, and there are not too many anchor bolts. Although the movable jaw is a casting part, its surface is smooth and spray paint is exquisite. The flywheel of the engine block has a unique number, which is consistent with the instruction manual. The whole machine is refined
Conclusion from the design, configuration, material, assembly, operation, maintenance and other aspects of C series jawbone machine, it is safe, convenient, efficient and perfect, which is unmatched by domestic machine. Foreign manufacturers of jawbone machine, such as Nordberg, telsmith, kuc Ken, etc; Svedala, Sweden; Krupp, KHD, Germany; Kobe Steel, etc. They have a certain advantage in the market e to their excellent manufacturing, high reliability, good performance and advanced automatic control technology. Only when we see the gap can we know the direction of our efforts. In the future, domestic equipment can be developed in the following aspects:
(1) humanized design. Fully considering the safety of operators, maintainers and the equipment itself, the design of C80's feed observation shield, discharge belt protector and spring guard will rece the possibility of personal and equipment accidents, which will rece intangible losses to users. It is very popular with users
(2) mechatronics and intelligence. Since the 1980s, people pay more attention to high efficiency and energy saving, and pay more attention to the synchronous development of mechatronics and electronic control technology. The combination of machinery and electronics, mechanical technology and control technology, information technology, sensor technology make the development of Mechatronics crushing equipment and a new generation of intelligent crushing equipment become a reality (3) finish machining and high quality. Compared with well-known foreign manufacturers, there are obvious gaps in processing quality and material quality; Change the big and stupid image, replace the small and refined shape, start from each screwthe first problems existing in China's mining machinery instry are as follows: first, the comprehensive strength of mining machinery enterprises is not strong, and most enterprises are stagnant in terms of energy and capital investment in scientific research, new proct development, technological transformation and enterprise management. The domestic mining machinery procts, especially the key equipment urgently needed by the national construction, can not meet the requirements, and there are some problems, such as low technical content, low added value, unstable proct quality, low labor proctivity, etc., which cause the output value growth rate and profit growth rate of mining machinery manufacturing enterprises in our country is not commensurate
secondly, there are problems in proct variety, technology, quality and service, which lead to the low actual contribution rate of domestic mining machinery instry to mines. Taking metallurgical mines as an example, there are 1180 kinds of equipment in use at present. Only about 26% of the equipment can be self-sufficient in China, and most of them are low technology and low quality equipment. The rest
74% still need to be imported. Domestic equipment, especially mobile equipment with high technology content, such as full face roadheader, mining truck, excavator, scraper and so on, has a big gap compared with imported equipment
in terms of equipment manufacturing, China's mining machinery enterprises are relatively backward in both technology and experience, and have no perfect equipment. If we want to improve the comprehensive strength of China's mining machinery instry, we must first make efforts in scientific research and technological transformation and independent innovation. Since its establishment, Xinhai Mining Machinery Co., Ltd. has been adhering to the road of independent innovation, and the comprehensive energy saving of the world's first full section airlift micro bubble flotation machine can reach more than 85%; The superfine laminated autogenous mill has no st pollution and can double the capacity of the ball mill<
according to the analysis report on the development prospect prediction and investment strategic planning of China's mining machinery instry published by the Research Institute of prospective instry, the innovation of mining machinery instry can be achieved through the following ways:
firstly, the mining machinery manufacturing instry should establish different forms of alliances with foreign companies and domestic professional design institutes, including the formation of groups, consortia, the introction of technology, the introction of new technologies, the establishment of new technologies and the establishment of new technologies To introce talents, we should at least strive to adopt the method of joint design in a certain engineering project, first intervene and then improve, so as to achieve a win-win situation
secondly, it is necessary to establish and improve the Application Laboratory of advantage specialty as soon as possible to carry out the application technology research of proct and manufacturing process. The laboratory should start high and be practical; It includes test theory and method, test equipment and scale, control and detection technology. If necessary, foreign advanced technology should be introced. In addition, the related colleges and universities at home and abroad are not only the training base of mining machinery technical personnel, but also the origin of basic theory and experimental technology research of mining machinery, so we must take different forms of cooperation with them with the help of their strength.