氡室平衡状态对监测曲线的影响及修正

氡在氡室中是一种动态稳定状态,为了更准确的监测氡室中氡浓度的变化,文章主要对氡室首次补氡期间氡及子体的平衡状态的变化进行理论推导和平衡系数对FD125监测曲线的影响进行了探讨并进行了修正,取得了比较好的效果,为氡室氡浓度监测曲线修正提供了一种方法.     

Tectonic Factor in the Formation of the Radon Fields in the Atmosphere of the Tashkent Subway

Using the standard radiometers -GUARD PQ2000M and gamma-TRACER (Germany) and semiconductor spectrometers RATON (Uzbekistan), the radon fields were investigated in underground service enclosures and on the platforms of the Tashkent subway stations located on territories with different geotectonic characteristics. It is shown that the tectonic factor influences the formation of radon fields in the air in the subway station. 4 figures, 1 table, 7 references.     

On the use of the conjugate gradient method for the solution of the neutron transport equation

The possibility of using the standard conjugate gradient (CG) method to directly solve the S_n-equations based on the diamond difference scheme is studied for mono-energetic neutron transport problems with isotropic scattering. It is shown that such a direct use is possible for practical heterogeneous problems with a significant speed-up over the conventional source iteration (SI) method except for the problems that are prone to unphysical negative fluxes. Some recipes are suggested to make use of the CG-method even in those cases which need negative flux fix-up in the SI-method. The transport synthetic acceleration scheme, recently developed by Ramone [Nucl. Sci. Eng. 125 (1997) 257] and others, is shown to be useful in such cases. A symmetrisation scheme for the coefficient matrix has also been presented to enable the use of the CG-method. This scheme is compared with another approach of using weighted inner products.     

The research about the time-effect of the wettability on the wool surface treated by the Ar plasma jet in the atmospheric pressure

A facility which is called atmospheric pressure and normal temperature plasma jet was introduced in this paper. After the wool surface was treated by this kind of facility with Ar in different irradiating times, the time-effect of the fabric wettability has been weakened, and if the parameters of the irradiating time and the voltage of the facility are appropriate, the time-effect of wettability can be effectively inhibited. With the stable wettability, the fabric can be dressed without PVA (polyvinyl alcohol) which can cause lager pollution in the textile field, so the method without the time-effect of the textile wettability will be useful in the field of clean textile production. Undoubtedly, the stable wettability of textile surface was caused by the stable hydrophilic molecules on the textile surface. Thus, the reaction process and results on the textile surface treated by plasma needs to be studied to optimize the parameters of the irradiating time and the voltage of the plasma jet. So the initial experimental studies on the optimization of the parameters of the plasma jet were discussed in this paper, and the authors believe that the method without the time-effect also can be used in other fields of plasma application.     

Effect of the Discharge Voltage on the Performance of the Hall Thruster

In this paper,a two-dimensional physical model is established according to the discharging process in the Hall thruster discharge channel using the particle-in-cell method.The influences of discharge voltage on the distributions of potential,ion radial flow,and discharge current are investigated in a fixed magnetic field configuration.It is found that,with the increase of discharge voltage,especially during 250-650 V,the ion radial flow and the collision frequency between ions and the wall are decreased,but the discharge current is increased.The electron temperature saturation is observed between 400-450 V and the maximal value decreases during this region.When the discharge voltage reaches 700 V,the potential distribution in the axis direction expands to the anode significantly,the ionization region becomes close to the anode,and the acceleration region grows longer.Besides,ion radial flow and the collision frequency between ions and the wall are also increased when the discharge voltage exceeds 650 V.     

Design of the exhaust system in the confinement of the HTR-10

The modular high temperature gas-cooled reactor has a vented confinement instead of a gastight pressurized containment due to its passive safety features. The safety class negative pressure exhaust system is used in the heating, ventilation and air conditioning system to fulfill all kinds of safety-related functions at the normal operation and during accidents. This paper introduces and reviews the design of safety class negative pressure exhaust systems of the 10 MW high temperature gas-cooled reactor-test module.