偶联剂处理硅灰石填充不饱和聚酯树脂的研究

对针状硅灰石 (L∶D≥ 10∶32 5目 )提纯后 ,采用偶联剂进行表面处理 ,将硅灰石按不同比例填充于不饱和聚酯树脂体系中 ,研究了材料的性能。结果表明 ,改性后的硅灰石可显著改善不饱和聚酯的性能。     

纳米4-H碳化硅薄膜的掺杂现象

对纳米晶SiC薄膜进行了P和B的掺杂,B掺杂效率比P高,其暗电导预前因子与激活能遵守Meyer-Neldel规则,并有反转Meyer-Neldel规则出现.掺杂效率比非晶态碳化硅薄膜高是纳米碳化硅薄膜的特点之一.非晶态中的隧穿和边界透射对输运有一定贡献.     

YAG激光熔覆的研究现状与发展趋势

本文介绍了YAG激光熔覆的特点，并与CO2激光进行了比较，显示了YAG激光熔覆的优势和潜力。叙述了YAG激光熔覆的研究进展及其应用前景。     

Auto-analysis system for graphite morphology of grey cast iron

The current method to classify graphite morphology types of grey cast iron is based on traditional subjective observation, and it cannot be used for quantitative analysis. Since microstructures have a great effect on the mechanical properties of grey cast iron and different types have totally different characters, six types of grey cast iron are discussed and an image-processing software subsystem that performs the classification and quantitative analysis automatically based on a kind of composed feature vector and artificial neural network (ANN) is described. There are three kinds of texture features: fractal dimension, roughness and two-dimension autoregression, which are used as an extracted feature input vector of ANN classifier. Compared with using only one, the checkout correct precision increased greatly. On the other hand, to achieve the quantitative analysis and show the different types clearly, the region segmentation idea was applied to the system. The percentages of the regions with different type are reported correctly. Furthermore, this paper tentatively introduces a new empirical method to decide the number of ANN hidden nodes, which are usually considered as a difficulty in ANN structure decision. It was found that the optimum hidden node number of the experimental data was the same as that obtained using the new method.     

Adiabatic shear bands on the titanium side in the titanium/mild steel explosive cladding interface: Experiments, numerical simulation, and microstructure evolution

The microstructure and microtexture in adiabatic shear bands (ASBs) on the titanium side in the titanium/mild steel explosive cladding interface are investigated by means of optical microscopy, scanning electron microscopy/electron backscattered diffraction (SEM/EBSD), and transmission electron microscopy (TEM). Highly elongated subgrains and fine equiaxed grains with low dislocation density are observed in the ASBs. Microtextures (25 deg, 75 deg, 0 deg), (70 deg, 45 deg, 0 deg), and (0 deg, 15 deg, 30 deg) formed within the ASBs suggest the occurrence of the recrystallization. The grain boundaries within ASBs are geometrically necessary boundaries (GNBs) with high angles. Finite element computations are performed to obtain the effective strain and temperature distributions within the ASBs under the measured boundary conditions. The rotation dynamic recrystallization (RDR) mechanism is employed to describe the kinetics of the nanograins’ formation and the recrystallized process within ASBs. During the deformation time (about 5 to 10 μs), the following processes take place: dislocations accumulate to form elongated cell structures, cell structures break up to form subgrains, and subgrains rotate and finally form recrystallized grains. The small grains within ASBs are formed during the deformation and do not undergo significant growth by grain boundary migration after deformation.     

氢化非晶硅磷掺杂工艺条件的研究

本文对氧化非晶硅磷掺杂的工艺条件进行了研究，得出掺磷氢化非晶硅的电导率随衬底温度、气体流量、气体压力、射频功率、淀积时间的变化关系，为非晶硅的有效掺杂和器件研究提供了依据。     

深大露天矿综合开采工艺主要设计参数的研究

深大露天矿的间断向半连续开采工艺过渡时，合理深度及半连续开采工艺的移设步距是两个重要的开采参数，对矿山的经济效果影响巨大，本文首次提出采用组合台阶单位体的开采来分析确定这两个重要的参数，得到的结论在霍林河煤矿的应用中取得了满意的结果，对其它类似矿山具有应用价值。     

激光光束质量因子M~2的物理概念与测试方法

激光光束传输质量因子Ｍ２是一种全新的描述激光光束质量的参数，它能定量表征单模、多模光束传播特性。本文介绍Ｍ２的物理概念、特点、测试方法及近年来国外的研究概况。     

Exterior stable domain segmentation integral equation method for scattering problems

This paper is concerned with the development of an exterior domain segmentation method for the solution of two- or three-dimensional time-harmonic scattering problems in acoustic media. This method, based on a variational localized, symmetric, boundary integral equation formulation leads, upon discretization, to a sparse system of algebraic equations whose solution requires only O(N) multiplications, where N is the number of unknown nodal pressures on the scatterer surface. The new procedure is analogous to the one developed recently¹ except that in the present formulation we avoid completely the use of the hypersingular operator, thereby reducing the computational complexity. Numerical experiments for a rigid circular cylindrical scatterer subjected to a plane incident wave serve to assess its accuracy for normalized wave numbers, ka, ranging from 0 to 30, both directly on the scatterer and in the far field, and to confirm that, contrary to standard boundary integral equation formulations, the present procedure is valid for critical frequencies.