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        What does boric acid do

        Boric acid is a white powdery crystal or a scaly lustrous crystal on a triclinic axis, with a smooth hand feeling and no odor. Dissolved in water, alcohol, glycerin, ethers and essential oils, the aqueous solution is weakly acidic. It is widely used in the glass (optical glass, acid-resistant glass, heat-resistant glass, glass fiber for insulating materials) industry, which can improve the heat resistance and transparency of glass products, increase the mechanical strength, and shorten the melting time.
          During the moderation process,
          U-235 produces fast neutrons after fission reaction. The fast neutrons move in the moderator, their energy gradually attenuates, and finally become thermal neutrons. This period of time is called moderation time, and this process is called moderation process. . Fast neutrons may not be absorbed immediately after they become thermal neutrons. They will move for a period of time before being absorbed. This period of time is called diffusion time. In the moderating process, a moderator can be used. The role of the moderator is to slow down the neutrons so that the neutrons can easily react with the target nucleus. The prerequisite for the moderator is to have a large scattering cross section and a small absorption cross section, so that the moderating effect is good, and the best moderation is The agent is heavy water, as well as carbon dioxide, carbon, water, boron-10 isotopes and so on.
          Boric acid absorbs neutrons
          Boric acid is a substance with a large neutron absorption cross section. It is mainly used to adjust the reactivity in the reactor. Adding an appropriate amount of boric acid can reduce the reactivity.
          Natural boron has two stable isotopes, namely ~(10)B and ~(11)B, with abundances of 19.78% and 80.22%, respectively. ~(10)B has the unique characteristics of high neutron absorption, ~(10)B has a thermal neutron absorption cross-section of 3837 bar (1b=10, Pa), the natural abundance of boron absorbs thermal neutrons The cross section is close to 750 bar, while ~(11) is only 0.005 bar, so the absorption cross section of ~(10)B for thermal neutrons is more than 5 times that of natural abundance of boron and more than 20 times that of graphite. More than 500 times the traditional protective material concrete. In other words, boron-10 isotope is a highly efficient thermal neutron absorber. Therefore, it is indispensable in safety and control systems in nuclear power plants. Special grade (SQ) boric acid is used in the nuclear industry and has a high ratio of boron-10. Therefore, boric acid can be used to terminate the nuclear reaction, absorb neutrons, and then block it with quick-setting cement. From now on, how many kilometers around this place will be an uninhabited area and will no longer be inhabited.
          It is precisely because of this characteristic of ~(10)B isotope that related products of ~(10)B isotope are widely used in military protection, nuclear weapons and nuclear industry. Another effect of boric acid is that it can vitrify at high temperature, which can fix the radioactive elements to diffuse around. (It is like firing glass in a glass factory)
          In addition, the boron-10 isotope can also be used for neutron counter tubes, used as shields and alignment rods in nuclear reactors, and also used to treat cancer.
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