国产日韩亚洲大尺度高清,国产高潮流白浆喷水免费网站,97久久综合区小说区图片区,精品国产免费第一区二区三区

Strontium-90 tungsten radiation shielding is usually used to shield the radiation released by strontium-90.Strontium-90 (⁹⁰Sr) is a radioactive isotope of strontium produced from a nuclear explosion or nuclear fuel. Naturally occurring strontium is nonradioactive and nontoxic, but ⁹⁰Sr is a radiation hazard. It undergoes β− decay with a half-life of 28 years, and a decay energy of 0.546 MeV distributed to an anti-neutrino and the yttrium-90 isotope. Strontium-90 is one of the fission products of uranium-235. In the wake of Japan's Fukushima Daiichi nuclear power plant, the strontium-90 in the air have been detected in the regions outside of Fukushima and Miyagi. Some tiny radioactive dust can suspend in the atmosphere for many years, and pollute the air. Strontium-90 tungsten radiation shielding is usually used to shield the radiation released by strontium-90.

Strontium-90 has applications in medicine and industry. In industry, it is used as a radioactive source for thickness gauges to automatic control and measure the relevant parameter in the industrial processes, and in medicine as a radioactive source for superficial radiotherapy of some cancers, such as haemangioma, capillary hemangioma and other hemangioma diseases. β rays released from the strontium-90 act on the ionization of hemangioma vascular endothelial cell to achieve the absorption behavior of hemangioma, the gradual emulsification, solidification and contraction of hemangioma microvascular and to slow down, suppress or even stop the division of hyperplasia tissue cells. Controlled doses of ⁹⁰Sr and ⁸⁹Sr can be used in treatment of bone cancer.

Strontium-90 is a high toxicity radionuclide easy to accumulate in the human skeleton series, increasing the risk of bone cancer or leukemia. Strontium-90 can produce internal and external irradiation effects on human body. Its concentrations in the lung is usually larger, and therefore the lung tissue always subject to a strong irradiation. In large doses of irradiation, strontium-90 can do harm on humans and animals to some extent; while in low doses of irradiation which outside the allowable range, strontium-90 can also cause chronic radiation sickness or chronic skin damage. Such as in the case of 400rad, 5% people affected by irradiation died; in the case of 650rad, then the death rate ups to100%.

Strontium-90 tungsten radiation shielding may be used to shield the radiation released by strontium-90. Strontium-90 tungsten radiation shielding is made up with a high-density tungsten alloy, thus it has excellent radiation shielding performance that can absorb and shield the radiation to reduce the extent of damage to the human body.