Abstract:Based on the classical one-dimensional particle migration model， a three-dimensional particle migration model with a double deposition model was established， which considered both the sieve effect and the adsorption effect. Using Laplace and Fourier transforms the general solution of particle migration in saturated semi-infinite porous media under one-dimensional seepage and three-dimensional dispersion conditions is derived. According to the basic solution of point source injection on a semi-infinite body surface， the analytical expression of circular surface source injection is obtained by the integral method. The correctness of the understanding is verified by the degradation of the solution and the parameter inversion of the breakout curve. The influence mechanism of the hydrodynamic dispersion coefficient， sieve coefficient， particle adsorption coefficient， and particle desorption coefficient on the particle migration process was analyzed under constant concentration injection of the circular surface source. The results show that the hydrodynamic dispersion effect accelerates the migration of particles， making the breakthrough time faster and the peak concentration higher. The larger the sieving coefficient and particle adsorption coefficient， the smaller the particle release coefficient， the more particles deposited on the solid matrix， and the smaller the peak particle concentration in the pore. In the case of constant concentration injection of circular surface source， the concentration of particles in porous media increases with time and decreases with depth， and tends to 0 during particle injection. After particle injection is stopped， the concentration of particles in the porous media decreases with time， and there is a concentration peak in depth. The depth of the concentration peak increases with time.

Abstract:In order to master the regularities of dust movement with time and space in the screening workshop of asbestos concentrator and obtain the optimized parameters of dust removal by ventilation,screening workshop of No. 1 concentrator in Mangya Asbestos Mine was considered as the research background. Based on the theory of gas-solid two-phase flow,the discrete phase model (DPM) of computational fluid mechanics was used to simulate the dust concentration in screening workshop. By comparing with field measurement of dust concentration distribution,simulation results are essentially coincident with the measured data. The results indicate that the dust concentration near the screening equipment is higher,and the value decreases as the distance from the screening equipment increases. The dust concentration is lower under trap wall condition than the reflect,and the dust trapping effect is better. The dust settling effect is better when the inlet wind speed is about 0.6 m/s. When the exhaust dust cover is installed and the wind speed of main exhaust pipes is maintained at 14 m/s,the average dust-removal efficiency can reach 90%,and the asbestos fiber concentration can be controlled below 2.52 f/mL.

Abstract:An endophytic actinomycete strain OsiSh-10 significantly against rice blast pathogens was successfully isolated from Xiangaizao 7 rice (Oryza indica) of Liuyang Dawei Mountain in Hunan Province. The control effects of OsiSh-10 on leaf blast in field were investigated by coating seeds and spraying leaf of rice with it, which were as follows: leaf blast was controlled by spraying OsiSh-10 on leaf of rice , but coated seeds with OsiSh-10 unworked for leaf blast. According to its morphological features, culture characteristics, physiological and biochemical characteristics, 16s rRNA gene sequence comparison, and phylogenetic tree construction analysis, OsiSh-10 strain was classified as Streptomyces albus. OsiSh-10 strain is a promising biocontrol actinomycete for rice blast.

Abstract:提出了一种可以准确定位容差模拟电路软硬两类故障的模糊软故障字典法．该方法依据支路屏蔽的概念，求取电路的支路集屏蔽电流，并由元件参数分布规律计算容差对端口特性的影响，以此建立故障字典并构造故障阈值函数，从而实现容差电路的故障检测．在此基础上，应用网络分析与模糊数学，提出了一种故障隶属函数，据此进行容差电路的故障定位．该法有效地避免了故障因素与容差因素的相互交叠，大大降低了故障与容差间的模糊性．仿真试验表明，此法故障定位准确性高。