2012年3月31日星期六

How many kinds of directory?


Directory includes:

Tungsten Directory, jobs directory of directories for the directory, with a total catalog

Integrated directory, auto directory, alphabetical directory,

subdirectory Resource Directory Assets directory, see directory, a card catalog,

book catalog, comments, directory Theme directory, home directory, the root of the volume,

volume, directory, volume table of contents Seed catalog, local directory, center directory,

static catalog, instruction directory Evidence directories, banned directory, site directory,


exhibit catalog, lifting directory Directory structure, saving directory, temporary directory,

temporary resident directory in a directory on Source directory, the original catalog,

e-mail directory, pre-cataloging, notice directory Grammar directory, test directory,

user directory, business directory, page directory Page catalog, samples, catalog,

performance directory inquiry catalog, select a directory Inverted directory, current directory,


the directory of the virtual disk, catalog, catalog, Book catalog, the prices of goods catalog,


cluster table of contents, Active Directory, secondary directories Novel catalog, catalog sales,

inventory, global directory, the export directory Linear directory, active directory, drawers directory,

system directory, goods and materials directory Charts directory, product catalogs,

the problem directory, illustrated catalogs, inserts directory Check the directory,

the startup directory, bibliographies, file directory, the operation directory Common directory, collection directory,

see directory, materials directory, property directory Supplementary catalog, the auction catalog, a shared directory,

working directory, image directory Catalog of drawings, icons, directories, books, directory, table directory Root directory,

cataloging, compiling directory, communications, directory, cataloging


Tungsten Directory

2012年3月29日星期四

What is Tungsten ?


What is Tungsten ?

Tungsten (pronounced /tʌŋstən/), also known as wolfram (/wlfrəm/), is a chemical element with the chemical symbol W and atomic number 74. Tungsten is as known the heaviest materials except gold of the nature resources, for the density of tungsten is 19.25  g•cm−3(near r.t.). For the same reason, tungsten related products, alloys(Nickel-Copper-Ferro Binder), other elements doped(Al-doped, Th-doped, La-dope, Ce-dopd and K-doped) and carbides( carbonized tungsten powder with cobalt or Nickel binder) have the special ccharacteristics as pure tungsten, then it always named heavy stone.

Tungsten is a typiacl element of transition element Group VI and shows oxidation states from +6 to-2 and, particularly in its oxides, forms many non-stoicheiometric compounds. There is little aqueous chemistry except that of complex oxy-anions and some complex halides. The hexahalides are moleular but lower halides are polymeric and the lowest halides show extensive W-W bonding (more than Mo). Carbonyl and phos-phine derivatives are typical low oxidation state compounds. Complexes are formed, particularly by O-and S-ligands in higher oxidation states and by P-ligands in low oxidation states. Complex cyanides are well established.

Tungsten is one of Nonferrous Metals, and also it is as molybdenum and rare earth which are Refractory Metals, in the modern industrial time, it is the most important Strategic Metals for IT industrial and military industrial.
What is the problem with tungsten? Tungsten dissolves readily in water and is mobile under some field conditions, challenging initial assumptions with regard to tungsten’s fate and transport characteristics. Other concerns include data (occupational, animal studies, cancer clusters) indicating adverse non-cancer and cancer health effects and risk outcomes.
How is tungsten used? Tungsten alloys are good conductors of electricity, and used primarily to increase the toughness and strength of steel. The most common tungsten product, cemented tungsten carbide, is used to make grinding wheels and cutting or forming tools. Tungsten powder is used as a lead replacement in bullets. However, firing of a tungsten/nylon bullet introduces tungsten and other projectile related metals into the environment.
How does exposure to tungsten affect human health?
The toxicology of tungsten depends on the route of administration, the solubility of the constituent and the duration of exposure. Occupational exposure via the inhalation pathway has revealed elevated levels of pulmonary fibrosis (scarring of the lung tissue) and other effects including asthma and inflammation of the nose tissues.  Research also suggests that the combination of tungsten and other substances can be linked to the development of lung cancer.  Some animal data suggests that tungsten could cause adverse developmental and reproductive effects (including the kidneys as a target organ). Information from Nevada has drawn attention to tungsten’s potential toxicity as exhibited in the Fallon Nevada cancer cluster.

The tungsten directory site contains a lot of knowledge on tungsten products

Tungsten Directory Website



2012年3月28日星期三

Tungsten Alloy Military From Tungsten Directory Site

Tungsten heavy alloys are usually consisted of W-Ni- Fe or W-Ni- Cu or even W-Ni-Cu-Fe, some tungsten alloy is added Co, Mo, Cr, etc. It could be made as many shapes. Tungsten heavy alloy sphere has a wide application in military filed.

Advantages of tungsten alloy sphere for military
With the highest densities weighting in at 1.7 times heavier than lead, tungsten is the best ideal material for military defense used in military. On the other hand , tungsten is non-toxic, so it is the related product for lead which was used in bullet and shot to reduce the environmental hazardous materials in the military field. As well owing to its great hardness and resistance to high temperature, tungsten alloy sphere has been applied in military defense increasingly today.

Applications of tungsten alloy sphere for military
Tungsten alloy sphere can be also used as bullets or pellets in many military filed.

These are the pellets from inside a shotgun shell. Lead shot and bullets have been banned in many areas because they poison the environment. The main substitute materials are steel, bismuth and tungsten. The main advantages of tungsten alloy ball which made as pellet are that it's very dense, and very hard. The density allows the pellets to fly long distances without slowing down, while the hardness allows the pellets to keep their shape while being accelerated by the powder charge, which increases the muzzle velocity.

As well tungsten alloy spheres are widely used in hand grenade, armor piercing projectile, prefabricated fragments.

Tungsten alloy sphere is in small volume with high density, which means it could be used in some fields need the little but heavy parts, such as counterweights for military defense, projectiles in the missile weapons, armor piercing ammunition, hunting equipment, counterweights for hunting gun, prefabricated fragments, the missile weapons, armor piercing ammunitio,  tungsten alloy bullet.


Tungsten alloy/Tungsten alloy military spheres
Tungsten alloy/Tungsten alloy military sphere 


Tungsten alloy military from tungsten directory site.
If you want to know more about tungsten alloy military knowledge, you must enter the tungsten catalog this website. The tungsten directory This site has a lot of knowledge.

2012年3月27日星期二

Tungsten jewelry for tungsten directory sites inside

Jewelry or jewellery is a form of personal adornment, such as rings, necklaces, earrings, and bracelets etc. Jewelry normally differs from other items of personal adornment as it has no other purpose than to look appealing, and humans have been producing and wearing it for a long time. Jewelry can be made from a wide range of materials, such as tungsten, stainless steel, titanium, ceramic, iron, copper, etc., and the formal four materials are the most popular materials.

Tungsten Jewelry is making a revolution in the jewelry industry by introducing unique types of designs. Tungsten carbide jewelry includes tungsten ring, tungsten chain, tungsten necklace, tungsten earring, tungsten watch etc. Combined with carbon and other elements, tungsten jewelry is roughly 10 times harder than 18k gold and four times harder than titanium, and takes a brilliant high polish and resists scratching longer than any metal ever offered to the public, and will never bend out of shape.

Some beautiful ring pictures as below:
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Stainless steel jewelry as a durable and nearly indestructible form of alloy is a quickly growing style of jewelry, and able to withstand typical wear and tear. Many people are wearing stainless steel rings, stainless steel bracelets, and stainless steel necklaces, stainless steel earrings and so on.


Titanium jewelry is one of the most popular jewelry at the best prices, traditionally, titanium and tungsten were used in aircraft manufacturing, medicine and aerospace engineering. Today, titanium rings, titanium bracelets, titanium necklaces, titanium earrings are warmly welcomed by people.

Ceramic jewelry as an important part of ceramic products, is appreciated by many people for its unique designs. Ceramic jewelry includes ceramic ring, ceramic necklace, ceramic bracelets, ceramic earing.

If you want to see more about tungsten products, you can into tungsten directory website, tungsten directory site provides all the products.

2012年3月26日星期一

What is tungsten?

Tungsten, a metal element. Atomic number 74, atomic weight 183.85. Steel gray or silver-white, high hardness, high melting point and room temperature from air erosion; the main purposes for the manufacture of the filament and high-speed cutting alloy steel, super-hard molds, but also for optical instruments, chemical apparatus. China is the world's largest tungsten storage country.

Tungsten are non-ferrous metals, is also an important strategic metal tungsten mine in ancient times known as the "witherite". 1781 by the Swedish chemist Carl. William. She Yeer found that scheelite and extract new elements and acid - acid, and in 1783 by the Spanish found Depp Air Asia, the wolframite extracted acid, the same year, using the carbon reduction of tungsten trioxide first tungsten powder, and named the element. The tungsten content in the earth's crust is 0.001%. Containing tungsten minerals are found in 20 kinds. Tungsten deposits in general along with the activity and the formation of granitic magma. After smelting After the tungsten is silver-white lustrous metal, high melting point and hardness.

Tungsten ore mined in the world, about 50% for high-quality steel smelting, approximately 35% for the production of hard steel, about 10% for the system tungsten wire, about 5% for other purposes. Tungsten can be manufactured firearms, rocket propulsion nozzles, cutting metal blades, drill bits, super-hard molds, wire drawing dies, etc., the use of tungsten is widely involved in mining, metallurgy, machinery, construction, transportation, electronics, chemical industry, light industry , textile, military, aerospace, science and technology, in various industrial fields.

If you want to know more about the knowledge of tungsten, You can go to the site of the tungsten directoryTungsten directory site combines all the knowledge and content of the tungsten.

Stay tuned next tungsten contents of the directory.

2012年3月25日星期日

Tungsten directory and the new tungsten directory

The Tungsten directory is the world's first and tungsten catalog site, this site describes a number of tungsten-related website, for example, tungsten alloy, tungsten carbide sites, these sites is one of the important sites of the tungsten directory site, if you need to find the website of tungsten, preferably into the tungsten catalog this site, the URL of this site is www.tungsten-directory.com.
Or you can enter the new version of the English website of the tungsten catalog, the address of this site is www.tungsten-directory.com/index.asp .
The new tungsten directory sites graphics are as follows:
Famous tungsten directory web graphics as follows:

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