1. Chemical elements
2. Nickel and Biology
3. Electronic company
4. English abbreviation of national income: NI
[Edit this paragraph] 1. chemical element
Element symbol: nickel
English name: Nickel
Chinese name: Nickel
Bulk elastic modulus: GPa 180
Enthalpy of atomization: kJ /mol @25℃422.6
Heat capacity: j/ (mol k) 26.07
Conductivity: 10 6/(cm ω) 0. 143.
Thermal conductivity: w/(m k) 90.9
Heat of fusion: (kj/mol) 17.470
Heat of vaporization: (kJ/mol) 370.40
Content of elements in the universe: (ppm)60
Relative atomic mass: 58.7 Common valence: +2, +3.
Electronegativity: 1.9 1
Peripheral electronic configuration: 3d 4s2
Extranuclear electron configuration: 2,8,16,2
Isotopes and radiation: Ni-56 [6.1d] Ni-57 [35.6h] * Ni-58 Ni-59 [76,000y] Ni-60 Ni-61Ni-62 Ni-63 [1]
Electron affinity and energy:111.5 kj mol-1.
The first ionization energy is 737kJ mol- 1, the second ionization energy is 1753kJ mol- 1, and the third ionization energy is 3393kJ mol- 1.
Element density: 8.902g/cm3.
Melting point of single substance: 1453.0℃
Simple substance boiling point: 2732.0℃
Atomic radius: 1.62 angstrom
Ion radius: 0.69 (+2) a.
Covalent radius:1.15 a.
Common compounds: NiBr2 NiO NiSO4 NiS NiCl2.
Discoverer: Kronstadt Time: 175 1 Location: Sweden
Name source:
German: kupfernickel (fake copper).
Element description:
A hard and flexible silvery white metal. It exists in part of the earth's crust with an average content of 70 parts per million. It can be polished as bright as a mirror and will never rust under normal circumstances.
Element source:
It mainly exists in nickel pyrite [(Ni, Fe)9S8]. Nickel metal is produced by heating ore in a blast furnace, so the sulfur in the ore is replaced by oxygen. After the oxide is treated with acid, iron will react with the acid and nickel will remain.
Element usage:
Nickel can be used as coating metal, metal alloy, nickel-cadmium battery, catalyst and coin because of its corrosion resistance.
Introduction to basic knowledge:
In nature, the most important nickel ores are red nickel ore (nickel arsenide) and nickel arsenide (nickel arsenide sulfide). Cuba is the most famous nickel mine country in the world, and Dominica also has a large number of nickel mines.
Metal nickel is mainly used in electroplating industry, and the articles after nickel plating are beautiful, clean and not easy to rust. Ultrafine nickel powder is often used as catalyst in chemical industry.
Nickel is widely used in making alloys. Adding nickel to steel can improve mechanical strength. When the nickel content in steel increases from 2.94% to 7.04%, the tensile strength increases from 52.2 kg/mm2 to 72.8 kg/mm2. Nickel steel is used to manufacture machine parts that bear heavy pressure, impact and reciprocating load, such as turbine blades, crankshafts and connecting rods. Nickel steel containing 36% nickel and 0.3-0.5% carbon has a very small expansion coefficient, which hardly expands when heated and contracts when cooled. It is used to manufacture a variety of precision machinery and precision gauges. High nickel steel containing 46% nickel and 0. 15% carbon is called "platinum-like" because its expansion coefficient is similar to platinum and glass. This high nickel steel can be welded into glass. It is very important in bulb production and can be used as a substitute for platinum wire. Some precision frames are also made of this kind of platinum-like steel, and the lenses will not fall off from the frames because of thermal expansion and cold contraction. The alloy consisting of 67.5% nickel, 65,438+06% iron, 65,438+05% chromium and 65,438+0.5% manganese has great resistance, and is used to manufacture varistors and electric heaters.
Titanium-nickel alloy has the ability of "memory", and it has a strong memory. After a long time, it is accurate to repeat it tens of millions of times. Its "memory" ability is to remember its original shape, so people call it "shape memory alloy". It turns out that this alloy has a characteristic transition temperature. Above the transition temperature, it has a microstructure, while below the transition temperature, it has another microstructure. Different structures have different properties. For example, above the transformation temperature, Ti-Ni memory alloy is hard and strong, but below this temperature, it is soft and easy to cold work. In this way, when we need it to remember any shape, we can make it into that shape, which is its "permanent memory" shape. Below the transition temperature, because it is soft, we can make it deform at will to a considerable extent. When it needs to return to its original shape, it only needs to be heated above the transition temperature.
Nickel is magnetic and can be attracted by magnets. Alloys made of aluminum, cobalt and nickel are more magnetic. When this alloy is attracted by an electromagnet, it will not only be sucked away by itself, but also something 60 times heavier than it will not fall. This can be used to make electromagnetic cranes.
Nickel salts are mostly green. Nickel hydroxide is brownish black and nickel oxide is grayish black. Nickel oxide is usually used to make iron-nickel alkaline batteries.
Nickel ions are usually identified by dimethylglyoxime. In ammonia solution, nickel ion (Ni2+) reacts with dimethylglyoxime to form bright red precipitate (Ni(dmgH)2).
Method:
① electrolysis. The enriched sulfide ore is roasted into oxide, reduced to crude nickel with carbon, and then electrolyzed to obtain pure nickel.
② Carbonylation method. Nickel sulfide reacts with carbon monoxide to generate nickel tetracarbonyl, which is decomposed after heating to obtain high-purity metallic nickel.
③ Hydrogen reduction method. Nickel metal can be obtained by reducing nickel oxide with hydrogen.
[Edit this paragraph] 2. Nickel and biology
Food source:
Foods rich in nickel include chocolate, nuts, dried beans and cereals.
Metabolic absorption:
Nickel in diet passes through intestinal mucosa through intestinal iron transport system, and its absorption and transport process is not clear. The absorption rate of nickel is about 3% ~ 10%, which is reduced by milk, coffee, tea, orange juice and vitamin C. Iron deficiency or pregnancy and lactation can improve the absorption rate. Nickel absorbed by human blood is transported to the whole body through albumin, the main ligand in serum. Nickel also binds to L- histidine and α -macroglobulin in serum. 60% of nickel absorbed into blood is excreted through urine. The content of nickel in sweat is high, and bile can also excrete a lot of nickel. Nickel carbonyl exists in some environments. It is a colorless and transparent liquid with a boiling point of 43℃. It can be quickly inhaled by the respiratory system in the form of steam, and can also be absorbed by the skin in a small amount. After entering the body, about 1/3 of nickel carbonyl is excreted through exhalation within 6 hours, and the rest is absorbed into the blood through alveoli and finally excreted through urine. Only 17% of nickel carbonyl remained in the body 24 hours after inhalation, and all of it was discharged within 6 days.
Physiological function:
In higher animals and humans, the biochemical function of nickel has not been understood. But in vitro experiment, animal experiment and clinical observation provide valuable results.
1. In vitro experiments show the affinity of nickel thiamine pyrophosphate (cocarboxylase), pyridoxal phosphate, porphyrin, protein and peptide, and prove that nickel also binds to RNA and DNA.
2. The sensitivity of six kinds of dehydrogenases in the liver decreased when nickel was deficient, including glucose -6- phosphate dehydrogenase, lactate dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase and glutamate dehydrogenase. These enzymes are involved in NADH production, anaerobic glycolysis, tricarboxylic acid cycle and nitrogen release of amino acids. Moreover, nickel deficiency is characterized by structural changes of hepatocytes and mitochondria, especially irregular endoplasmic reticulum and decreased oxidative function of mitochondria.
3. The blood nickel content and iron absorption of anemia patients are decreased. Nickel can stimulate hematopoietic function. After nickel supplementation in humans and animals, red blood cells, hemoglobin and white blood cells increase.
Physiological needs:
Since the daily intake of nickel is 70 ~ 260μ g/d, the possible requirement of human body is 25 ~ 35μ g/d according to the results of animal experiments. ..
Excessive performance:
Intake of 250 mg of soluble nickel every day can cause poisoning. Some people are sensitive and will be poisoned if they ingest 600 μ g. According to animal experiments, chronic excessive intake or exposure can lead to the degeneration of myocardium, brain, lung, liver and kidney.
Nickel deficiency:
Animal experiments show that the lack of nickel will lead to slow growth and decreased fertility.
[Edit this paragraph] 3. Electronic company
1 (non-Intel, non-Intel architecture)
Besides Intel, many other manufacturers produce x86 compatible systems. Because of the patent right, their products are different from Intel's, but they can still run x86 instructions.
2 American National Instruments (NI) Limited (National Instruments)
National Instrument Company (NI) was founded in 1976, and its headquarters is in Austin, Texas. It is a listed company in the measurement industry (NASDAQ, NATI), with more than 50 branches and offices all over the world, and many system alliance members.
Leading technology:
As early as 1980s, with the birth of NI LabVIEW, a gold medal product, NI put forward the slogan of "software is instrument" and opened up a brand-new measurement concept of "virtual instrument". For 25 years, NI has been committed to developing a computer-based testing, measuring and automation platform. Long-term development goals ensure that NI products have long-term compatibility and enjoy perfect technical support.
A wide range of applications:
At present, NI provides more than 500 kinds of software and hardware products, which are widely used in electronics, machinery, communication, automobile manufacturing, biology, medicine, chemical industry, scientific research, education and other industries. From the car test in Japan, the design verification of pacemakers in Australia to the performance test of BT telephone lines, thousands of engineers and scientists all over the world are using NI products to achieve their common goal-faster, better and cheaper.
Best product:
NI's graphical measurement program development environment (LabVIEW), GPIB interface card, PXI modular instrument system, plug-in data acquisition card, VXI controller, TestStand and other products are second to none in the global measurement industry. LabVIEW and TestStand won the prestigious "Best Product of the Year" award in American measurement industry.
Strong user base:
NI has a huge user base-only 200 1 year, and more than 24,000 companies around the world have purchased NI products. The wisdom of users combined with Ni's advanced and high-quality products has created countless successful testing and measuring schemes. With the help of commercial computer platform, users can get the same or even better functions at half or even one tenth of the cost of traditional test and measurement systems.
Comprehensive after-sales service &; Professional technical support:
Now, in China, more and more scientific engineers and technicians begin to understand and apply nickel products. From well-known mobile phone manufacturers to private enterprises with only three or two members, thousands of NI users have actively adopted the measurement technology of NI. The headquarters of China Branch in Shanghai provides comprehensive and thoughtful sales service, professional technical consultation, after-sales product support and customer training. With the rich reference information of www.ni.com, the top ten technical support websites in the United States, you can quickly get familiar with NI products and use them at work.
With the growth of local users, we strive to provide better services. NI's measuring board or module guarantees the accuracy index, and comes with a detailed calibration certificate when leaving the factory, and can be recalibrated regularly. Now, Ni China Branch entrusts Shanghai Metrology Institute, a national metrology unit, to provide paid professional calibration services for users in need, and issue calibration certificates to ensure the long-term measurement accuracy of products.
[Edit this paragraph]
4. English abbreviation of national income: NI
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