1. They are:
bitcoin
the concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's ideas, the open source software was designed and released, and the P2P network was built on it. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system
bitcoin cash
bitcoin cash is a new version of bitcoin with different configurations launched by a small number of bitcoin developers
extended data:
virtual currency refers to non real currency. Well known virtual currency, such as network company's network currency, Tencent company's Q currency, Q point, Shanda company's voucher, Sina's Micro currency (used for micro games, Sina reading, etc.), chivalrous Yuanbao (used for chivalrous road game), silver pattern (used for bixue Qingtian game)
the popular digital currencies in 2013 are bitcoin, Leyte coin, infinite coin, quark coin, zeta coin, BBQ coin, pennies (Internet), invisible gold bar, red coin and prime currency. At present, hundreds of digital currencies are issued all over the world. Popular in the circle & quot; The legend of "bitcoin, Wright silver, infinite copper, pennies aluminum"
2. BTC (buttress thread coupling) trapezoidal thread coupling is an API standard thread connection type, which is commonly used in the connection of petrochemical pipes or tools, such as floating collar, guide shoe and pipe shoe used in cementing operation. The pitch is 8 teeth per inch and the tooth height is 1-1.2 mm. The external thread part 1 is designed with - 15 ° The end face shoulder 4 is connected with - 15 of internal thread part 2 after tightening ° Internal torque shoulder interference fit, after the internal and external threaded parts are tightened, at least one circle of threads closely fit, the top surface of thread teeth of threaded parts is parallel to the oil pipe axis, and the inner diameter D2 of internal thread 2 is approximately the same as that of external thread 1. Trapezoidal thread has excellent sealing performance, high connection strength and good anti torque make-up ability, so it can be used as an alternative to thickened thread or replace thickened thread in practical engineering
3. 1. BTC: chemical vocabulary
BTC is the abbreviation of (Trichloromethyl) carbonate. It is the abbreviation of a chemical substance, mainly composed of carbon, chlorine and oxygen. The chemical formula is c3cl6o3, which can be used as the substitute proct of highly toxic phosgene and diphosgene in the synthesis
BTC: enterprise abbreviation
BTC refers to BTC Yingqun enterprise from Taiwan, China, which is a large-scale high-tech enterprise developing and procing keyboard, mouse and recorder. BTC is famous for procing high-quality computer peripherals. BTC is the OEM keyboard and add-on card proced by famous brand EMPREX, ranking first in Taiwan, especially the third in the world
BTC: the concept of bitcoin was first proposed by Nakamoto on November 1, 2008, and was formally 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 BTC: engineering material
BTC (buttress thread coupling), full name of partial trapezoidal thread coupling, is an API standard thread connection type, which is commonly used in the connection of petrochemical pipes or tools, such as floating collar, guide shoe and pipe shoe used in cementing operation
5, BTC: e-commerce mode
BTC (business to customer) e-commerce is one of the categories of e-commerce by trading partners, that is, e-commerce of commercial institutions to consumers. This form of e-commerce is generally based on the network retail instry, mainly with the help of the Internet to carry out online sales activities. BTC is also known as B2C, B2C mode is the earliest e-commerce mode in China
4. At present, Chinese citizens are eligible to apply for APEC Business travel cards: (1) government officials engaged in APEC affairs or in charge of travel card business, as well as Chinese officials working in APEC organizations 2 Management personnel, main business personnel and technical personnel in large state-owned enterprises under central management 3 Personnel of local state-owned enterprises 4 Personnel of private enterprises 5 Chinese (mainland) personnel in Sino foreign joint ventures, wholly foreign-owned enterprises and Taiwan, Hong Kong and Australia funded enterprises. The above-mentioned persons must hold valid PRC passport and frequently travel to APEC economies e to work needs. They have no criminal record or have been refused visa by foreign countries, especially the economies implementing the travel card scheme.
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6. Buttress thread coupling is a kind of API standard thread connection type, which is commonly used in the connection of petrochemical pipes or tools, such as floating collar, guide shoe and pipe shoe used in cementing operation.
7. BTC partial trapezoidal thread oil casing
4.50 & # 39&# 39; 13.5 it should be the specification
8. The outer diameter is 2-7 / 8 & quot 6.5 refers to the weight per foot (6.5 pounds / foot), the corresponding wall thickness is 5.51mm, 8rd is the connection parameter, which refers to the thread per inch of 8 teeth round thread, l-80 is the API steel grade of the steel pipe, eue is the outer pier diameter of the pipe end, R2 is the length grade of the steel pipe, which is grade 2 (there are three length grades)
you can ask questions if you are unclear, thank you
9. Partial ladder buckle is a form of casing connection in oil field. It is an API standard thread connection type. It is commonly used in the connection of petrochemical pipes or tools, such as floating collar, guide shoe and pipe shoe used in cementing operation.
10. The direction is different.
