BTC outbreak
It was officially born on January 3, 2009
since 2015, the future of bitcoin has become more and more uncertain. On the one hand, bitcoin fell as much as 55.55% against RMB last year; In 2015, bitcoin fell by more than 30% against the RMB in the first half of January alone
bitcoin's "falling" reflects the "self-healing" of its value after "fanaticism" to a certain extent. According to statistics, in 2013, bitcoin rose from 1 ∶ 13.59 to 1 ∶ 731, with an annual increase of 5300%. This speculative driven inflation has affected the virtual currency property on which bitcoin relies
on the one hand, no country has defined it as a legal currency. On the other hand, in 2014, the US dollar rose significantly, and the prices of oil and bulk commodities fell correspondingly. The price trend of bitcoin is the same as that of the latter, becoming part of the asset allocation of some speculators, which highlights that its asset attribute is far greater than the monetary attribute
extended data
Security and credit risk have also become the reasons for the decline of investor confidence. Mt. GOx, once the world's largest bitcoin exchange, claimed in March last year that it had lost all its assets e to hacker attacks. Recently, it was revealed that its lost bitcoin was probably e to internal system manipulation
the regulatory environment of bitcoin is not optimistic, and Russia, Thailand and other countries have begun to implement strict control on it. In addition, the global stock market performed well last year, resulting in the diversion of bitcoin investment funds, and the crazy "mining" activities also rapidly increased the supply of bitcoin, which may lead to a trend of oversupply in the short term, leading to a sharp drop in the price of bitcoin
on January 3, 2009, Nakamoto g up the first batch of 50 bitcoins on a small server in Helsinki, Finland
on May 21, 2010, the first bitcoin transaction: Laszlo hanyecz, a Florida programmer, bought a $25 pizza coupon with 10000 BTC
on July 16, 2010, the price of BTC rose by US $0.08 from US $0.008. The first sharp price fluctuation shows the rise of new things
on July 17, 2010, the first bitcoin platform was established
on November 6, 2010, the price on mtgox reached $0.5, and the bitcoin economy reached $1 million
on December 7, 2010, the first portable device to portable device transaction was realized on Nokia 900, with a transaction volume of 0.42btc
on February 9, 2011, the price reached US $1 for the first time, which is equivalent to US $1. The news that BTC is equivalent to us dollar has been widely reported by the media, which has aroused people's great attention, and the number of new users has increased greatly. In the next two months, bitcoin and pound sterling, Brazilian currency, Polish currency exchange trading platform has opened
on March 18, 2011, the BTC / USD exchange rate hit a seven week low, falling to US $0.7
on August 20, 2011, the first bitcoin conference and World Expo were held in New York. Among Google trend counties, bitcoin's attention reached a new high, with a price of $11 at that time
on November 14, 2011, the price of bitcoin hit a new half year low of $1.99
on September 15, 2012, the bitcoin conference was held in London. At this time, the price of bitcoin was $11.8
on September 27, 2012, bitcoin fund was founded, and the price of bitcoin was $12.46
on November 25, 2012, the first bitcoin conference in Europe was held in Prague, Czech Republic. At this time, the price of bitcoin was $12.6
on February 19, 2013, bitcoin client v8.0 was released. At this time, the price of bitcoin was $28.66
on April 10, 2013, BTC set a record high price of $110
on May 9, 2013, BTC Chinese, the largest bitcoin reporting website www.sosobtc.com The company obtained the investment fund Union Square's US $5 million round a investment, and the price of bitcoin was US $112.09 at this time< On May 28, 2013, the Department of Homeland Security banned the virtual currency service of Liberty Reserve, a Costa Rican exchange company, for its suspected xiqian and unlicensed fund transfer business, U.S. prosecutors said that this will become the largest international xiqian lawsuit in history, with the scale of absorbing money reaching 6 billion US dollars. A large number of users, including China, will lose all their money. At this time, the price of bitcoin is 128 US dollars
in June 2013, Netcom said that the United States will withdraw from qe3, deflationary bitcoin and quantitative easing monetary policy, which are the relationship between the two
on June 27, 2013, the German Conference made a decision: holding bitcoin for more than one year will be tax-free, which is considered by the instry to recognize the legal status of bitcoin. At this time, the price of bitcoin is $102.24
on June 28, 2013, mtgox obtained the monetary service license issued by the financial crime enforcement network office of the U.S. Department of the Treasury. Transaction standardization may mean that bitcoin is on the right track, government risk is reced, and its pace of integration into the display economy will be accelerated. At the same time, it will play an exemplary role in other virtual currencies. At this time, the price of bitcoin is $97.99
on November 28, 2013, the bitcoin trading price of Mt. GOx, a popular bitcoin exchange, broke through $1000, reaching a record high of $1073
on November 29, 2013, the trading price of bitcoin on Mt. GOx, a popular exchange, hit a record high of US $1242, while the price of gold was US $1241.98 an ounce, surpassing that of gold for the first time.
The concept of bitcoin was first proposed by Nakamoto on November 1, 2008, and was officially born on January 3, 2009. According to the idea of Nakamoto, the open source software is designed and released, and the P2P network on it is constructed. Bitcoin is a virtual encrypted digital currency in the form of P2P. Point to point transmission means a decentralized payment system
bitcoin network generates new bitcoin through "mining". In essence, the so-called "mining" is to use computers to solve a complex mathematical problem to ensure the consistency of bitcoin network distributed accounting system. Bitcoin network will automatically adjust the difficulty of mathematical problems, so that the whole network will get a qualified answer about every 10 minutes. Then bitcoin network will generate a certain amount of bitcoin as block reward to reward the person who gets the answer
The reasons for the sharp rise of bitcoin are very complex, mainly e to the continuous admission of institutional users through the compliance channel. In short, many bitcoin holders do not really understand bitcoin itself, but just regard it as an investment proct with huge profits, but ignore its risks
the concept of bitcoin was first proposed by Nakamoto on November 1, 2008, and was officially born on January 3, 2009. According to the idea of Nakamoto, the open source software is designed and released, and the P2P network on it is constructed. Bitcoin is a virtual encrypted digital currency in the form of P2P. Point to point transmission means a decentralized payment system
unlike all currencies, bitcoin does not rely on specific currency institutions. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses the distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses the design of cryptography to ensure the security of all aspects of currency circulation
e to the decentralized programming of the bitcoin system, only 25 bitcoins can be obtained every 10 minutes, and by 2140, the maximum number of bitcoins in circulation will reach 21 million. In other words, bitcoin system is able to achieve self-sufficiency, resist inflation through coding, and prevent others from destroying these codes
in this global computer virus incident, mobile China also received a blackmail. Fortunately, the machine that received the email was a testing machine, which did not affect us. However, it's different for college students in the graation season. The thesis is locked, which is related to graation. So in the face of this outbreak of blackmail virus, how should we deal with it and what protective measures should we take<
first of all, let's understand the characteristics of this virus
the computer virus initiated by hackers will encrypt a large number of files on the system into files with. Onion suffix. After poisoning, they are required to pay bitcoin ransom to decrypt and recover the files, causing serious losses to personal data, and anti-virus software cannot decrypt these encrypted files. But we must not listen to the hacker's so-called "give money to decrypt" saying, because hackers do not necessarily keep their promises, in addition, bitcoin is expensive, and it is also a large number for ordinary users< Secondly, we need to pay attention to the background of the virus outbreak.
according to the domestic experts, according to the network security agencies, this is a virus attack event launched by lawless elements using the "eternal blue" leaked from NSA hacker's weapon library“ "Eternal blue" will scan windows machines with open 445 file sharing port, without any user operation. As long as the machine is turned on and connected to the Internet, criminals can plant blackmail software, remote control Trojan horse, virtual currency mining machine and other malicious programs in computers and servers
e to the previous outbreak of worms using port 445 in China, operators have blocked port 445 for indivial users, but the ecation network has no such restriction, and there are still a large number of machines exposing port 445. According to the statistics of relevant institutions, at present, more than 5000 machines in China are attacked by NSA "eternal blue" hacker weapons every day, and the ecation network is the hardest hit area
What are the coping methods
1. Close port 445, and you can search and query by yourself
2. At present, Microsoft has released a patch ms17-010 to fix the system vulnerability of "eternal blue" attack. You can install this patch for your computer as soon as possible
as for XP, 2003 and other Microsoft machines that no longer provide security updates, microblog professionals recommend using "NSA Arsenal immunity tool" to detect whether there are vulnerabilities in the system, and close the ports affected by the vulnerabilities, so as to avoid being attacked by blackmail software and other viruses
In my opinion, I don't know if it's right. We still need criticism and correction. I don't think this virus has anything to do with which way you use to access the Internet, and it also has nothing to do with which kind of computer (PC or laptop) you use. He mainly aims at some loopholes in the Current Windows operating system. We all know that when a software is downloaded, it must have the highest administrator authority to install the software on this computer. This should be a security policy of the computer operating system. However, there are loopholes in everything, and the operating system is no exception. For example, this virus outbreak, in fact, the patch was released as early as March, but many users didn't pay attention to it and didn't fix it. So, now as long as you are connected to the network, and the system vulnerability is not repaired in time, you can scan the port, use the vulnerability of a port, directly install the encryption software (virus) to your computer in the background, and encrypt your important files, so as to achieve the purpose of blackmail. So it's better not to turn off the self-renewal function of windows for convenience. At the same time, it's also recommended to turn off some ports that are not often used but are very dangerous, such as 445, 135, 137, 138 and 139—— Finally, WiFi is just a way to access the Internet. It can also spread viruses. So, quickly update and patch it .... There is also a video here. I think it's very good, but I don't know if I can watch it http://weibo.com/tv/v/?fid=1034 :
Internet security once again because of a large-scale outbreak of computer viruses and caused everyone's attention: bit virus. The emergence of this virus will make the computer's documents locked, hackers to coerce ransom, and most of the places are important units. For example, Chinese universities and British hospitals. The data of these units are very important. Most of the time, the school is not only an ecational unit, many key universities also undertake a lot of scientific research tasks. From a certain point of view, it also shows that hackers are very selective and targeted
Of course, the explanation given by Microsoft said that the virus was an attack against the vulnerability supplemented in March. In a way, hackers are also a test of users' security awareness. Microsoft has added software to the vulnerability in March. From this point of view, the hacker's attack is not brilliant. Because it is through the official patch, and then imagine no patch defects, so as to attack. Hackers also know the update awareness and security awareness of users. Of course, as a domestic company, 360 also seized this opportunity to quickly adjust the security housekeeper to check and kill the virusfrom this point of view, Microsoft's vulnerability supplement is targeted and prescient, and the possible vulnerabilities should be supplemented in time
from the user's point of view, this virus attack is different from the previous one. In the past, it is generally in the form of camouflage and loading to ince customers to take the initiative to download. And this time the virus is mostly spread through the LAN, as long as you boot, the virus will invade. The document cannot be opened normally
if this virus attack has any inspiration for us to use computers and pay attention to Internet security, I think it can be inspired from at least two aspects: the first is to strengthen the security of computer systems, such as using official patches to repair vulnerabilities in time; the other is to install regular anti-virus software, update it in time, and strengthen the firewall
in this paper, I would like to talk about some superficial understanding of this problem< First, we should fully understand the importance of developing computing ability
one of the aims of primary school mathematics teaching is to cultivate students' computational ability, and teachers must have enough understanding. Some teachers don't pay enough attention to the cultivation and improvement of students' computing ability, and they don't let students find the rules and interests of computing. This is a big obstacle to cultivate and improve students' computing ability, which must be removed. Computational ability is a necessary ability for students< Number and calculation are widely used in daily life, work and study. In the real world, from the perspective of mathematics, there are mainly three aspects: number, quantity and shape. However, measurement is inseparable from number and calculation, and the quantification of body size is inseparable from number and calculation. Therefore, number and calculation are the most basic tools for people to understand the objective world and the basic knowledge and skills that every citizen should master< Number and calculation are the basis for students to learn other mathematical knowledge and even other subjects. This part of the knowledge is not good, students can not enter the normal learning< Number and calculation play an important role in cultivating students' thinking ability. Mastering the process of number and calculation is also the process of cultivating students' abstract generalization ability. In this way, students also develop the ability of abstract generalization in the process of learning to master the knowledge of number and calculation
4. The teaching of number and calculation is concive to infiltrating the enlightenment ecation of dialectical materialism. The concept of number is graally formed and developed with the needs of human life and practice. When teachers want to teach the concept of number, the relationship between calculation method and calculation method, they can infiltrate the enlightenment ecation of dialectical materialism
Second, clarify the calculation theory and improve the teaching quality of calculation
in the teaching of calculation, teachers should pay attention to explain the principle of calculation and reveal the law of calculation, so that students can know what it is and why it is
1. The abstraction of arithmetic is a difficult point in primary school teaching. In teaching, we try to transform the abstraction into the concrete by means of visual demonstration, so as to make the arithmetic clear
2. Learn to operate with tools, explore and comprehend. Psychologists believe that thinking begins with action. To enable students to master mathematical knowledge and promote the development of thinking, it is necessary to build a bridge between image thinking and mathematical abstraction, and give full play to the role of learning tools. For example, if the students have difficulty in understanding the "method of making up ten" in addition within 20, we will ask them to come out with sticks to help them learn the calculation method of "making up ten" by playing with sticks
3. Contact with practice to deepen understanding. Using students' existing knowledge and experience to understand new knowledge is the main way to construct teaching knowledge structure. Properly using old knowledge in teaching, assimilating new knowledge through analogy, and realizing positive transfer of knowledge are concive to students' understanding of new knowledge and recognition of new knowledge structure. For example, when teaching the calculation method of decimal addition, we can use the rate relationship of RMB units that students are familiar with to explain the reason that decimal points must be aligned
4. Pay attention to perception and strengthen stimulation. For the parts that are easy to be ignored by students, we should pay attention to strengthen the stimulation intensity (such as emphasis on entering and leaving places, emphasis on the treatment of decimal points, etc.) to attract students' attention, leave students a clear and correct impression, and avoid and rece errors in future calculation
5. According to the characteristics that students are prone to illusion and thinking set, we should consciously differentiate and compare the similar concepts, rules and formulas, so as to promote the accurate differentiation of new and old knowledge
6. Practice in time to consolidate and improve. Carry out targeted exercises, strengthen the key points and difficulties in the calculation process, and strive to consolidate in class
7. Pay attention to feedback and correct in time. Timely feedback, find out the students' mistakes, help students analyze the reasons and correct the mistakes in time< Third, we should deal with the relationship between written and oral arithmetic
oral arithmetic is a kind of calculation method which can only calculate and get the results by thinking and language without any tools. It has the characteristics of fast and flexible
mental arithmetic is an important part of computing power. Oral calculation is the basis of written calculation and estimation. Both written calculation and estimation ability are developed on the basis of accurate and skilled oral calculation ability. Without a certain basis of oral calculation, the cultivation of written calculation and estimation ability becomes the water without source. In addition, mental arithmetic is widely used in daily life, proction and scientific research. Therefore, it is very important to insist on the training of oral arithmetic and listening arithmetic in teaching to improve students' computing ability
(1) oral arithmetic teaching must run through the whole process of primary school mathematics teaching. In the lower grades, basic oral arithmetic such as addition and subtraction within 20, multiplication within the table and division are arranged; The middle grade arranges some oral arithmetic which is the basis of written arithmetic and often used in daily life; In order to cultivate students' ability of using knowledge flexibly and their ability of oral calculation, senior students arrange some questions of using operation law to do oral calculation in exercises. Each teaching reference book puts forward the requirements for the oral arithmetic of this semester in stages. Teachers should make the cultivation of oral arithmetic ability to be implemented, and effectively improve students' oral arithmetic ability
(2) arrange oral calculation reasonably. In compulsory textbooks, the basic oral arithmetic, which is the basis of written arithmetic, is taught before written arithmetic, while some difficult but not the most basic ones are taught after written arithmetic, so as to further improve students' oral arithmetic ability. For example, addition and subtraction within 20 is an important foundation of addition and subtraction, and only oral arithmetic is taught. In addition and subtraction within 100, two digit addition, subtraction of one digit and integral tens, such as 27 + 6, 27 + 30, are the basis of both written and oral arithmetic. Therefore, this part of the content before the written calculation, only teaching oral calculation; It is more difficult for students to master double-digit plus or minus double-digit, so the first grade first teaches written arithmetic, and the second grade further requires oral arithmetic. In this way, students can not only learn written arithmetic, but also form a strong ability of oral arithmetic
(3) pay attention to the teaching of oral arithmetic. Oral examples should pay attention to the intuitive demonstration and operation to make students understand the calculation theory
(4) teach students oral arithmetic and develop their thinking. In order to improve students' ability of oral arithmetic, we should teach students correct methods of oral arithmetic. The methods are various, and we should guide students to choose the methods that they can easily understand and master. Never guide students to do oral arithmetic with the method of written arithmetic. Two digit addition: 28 + 37. I find that some students think like this: 8 + 7 = 15, indivial digit is 5, ten digit is 2 + 3 + 1 = 6, ten digit is 6. This is completely the idea of written calculation. In fact, you should think like this: 28 + 30 = 58, 58 + 7 = 75. You don't need to have a vertical pattern in your head
practice has proved that strengthening the training of oral arithmetic can not only improve the calculation level of students, but also develop their thinking ability< Fourth, encourage students to use simple algorithms to improve their ability and develop their thinking
simple calculation is a practical and effective method to improve students' calculation speed. Simple calculation often uses certain operation laws, such as addition calculation often uses addition exchange law, addition combination law, and multiplication exchange law, multiplication combination law, multiplication distribution law, etc. in multiplication calculation, some calculations are simplified from complex to easy. The study of simple calculation can not only improve the students' calculation speed, rece the calculation errors, but also help the development of students' thinking. Therefore, in the teaching process, teachers should strengthen the teaching of simple methods
in addition, let students remember some common data, which can simplify the calculation process and improve the calculation speed. I remember an ecator said that a person's memory before the age of 13 is the best. He can remember a lot of things at this stage. Although he doesn't know why and how, these things don't affect his memory. The unknown reasons of these knowledge will be solved with the growth of his age and the increase of his knowledge. Therefore, we should pay attention to the development of students' memory, especially before the age of 13. The content of calculation in middle and high grades is extensive, comprehensive and comprehensive. Some common operations are often encountered in real life. These operations have no specific rules of oral arithmetic, and must be solved by strengthening memory training. The main contents of my intensive training are as follows: 1) the square result of each number from 1 to 10 in the natural number; ② A method of oral calculation for the square result of two digit number of 5 on a digit; ③ Some specific calculation results, such as 125 × 8＝1000，25 × 4 = 100, 0.25 =, 0.75 =, 0.125 =, 0.375 =, 0.625 = etc. These special calculation results are frequently used in practice, homework and life. If we master and remember them skillfully, we can transform them into abilities, which play a good role in calculation and proce high efficiency< 5. Pay attention to cultivate the good habit of careful examination and calculation
the teaching of calculation also needs to train students to form the habit of careful examination and examination. Don't just shout "be careful!" to students, To teach methods, strict requirements, form habits, improve the accuracy of calculation
the new curriculum standard points out that we should pay attention to the cultivation of students' habit of inspection. Inspection is a good way, it can make people find their own mistakes in time and correct them in time. In the process of teaching, teachers should pay attention to strengthen the teaching of checking calculation, let students use different methods to test a problem, master the test method, and skillfully use this method to judge the correctness of the answers to similar problems
six relations between addition, subtraction, multiplication and division are often used in checking. The estimation is often based on the variation of proct and quotient. For example: according to the multiplier & gt; 1, proct & gt; Multiplicand (except 0); Multiplier = 1, proct = multiplicand; If the multiplier is less than 1, the proct is less than the multiplicand (except 0), you can judge which of the following questions is greater than the multiplicand, which is less than the multiplicand, and which is equal to the multiplicand: 8 × 、 nine × 、 one × 2、0.9 × 16、5 × 1、3 × 、 × 1 According to divisor > 1, quotient < divisor (except 0); Divisor = 1, quotient = dividend; If the divisor is less than 1, the quotient is greater than the divisor (except 0), it can be judged without calculation ÷ 14、8 ÷ 1 、21 ÷ 、 ÷ 7、2 ÷ 1、0.45 ÷ Is the quotient greater than the divisor, less than the divisor, or equal to the divisor< Sixth, enrich learning activities, be happy with teaching and learning, and stimulate students' interest
the calculation problem is composed of numbers and abstract operation symbols, which makes students easily feel irritable and tired. Therefore, teachers should
1. Disconnect the network, use anti-virus software to check and kill, and then use 360 system first aid kit to check
2. If you can't kill the virus, after backing up the important data, boot with the system disk, then format the computer partition, re install the system, and install the corresponding official system patch (kb4012598).