半不连续切屑流动速度的系统分析及切屑变形的度量

本文借助影片运动分析仪,对用高速摄影记录的钛合金切屑沿前刀面的流动规律进行了研究,并用系统分析法进行了描述,推导出能反映半不连续切屑不均匀变形过程的动态衡量参数,同时也导出了度量此种切屑塑性变形的准静态参数——等效切削比。     

分配计量多通阀技术分析

介绍了新型分配计量多通阀的系统原理、结构特点和关键技术.     

Order vs. Disorder: Cholesterol and Omega-3 Phospholipids Determine Biomembrane Organization

Lipid structural diversity strongly affects biomembrane chemico-physical and structural properties in addition to membrane-associated events. At high concentrations, cholesterol increases membrane order and rigidity, while polyunsaturated lipids are reported to increase disorder and flexibility. How these different tendencies balance in composite bilayers is still controversial. In this study, electron paramagnetic resonance spectroscopy, small angle neutron scattering, and neutron reflectivity were used to investigate the structural properties of cholesterol-containing lipid bilayers in the fluid state with increasing amounts of polyunsaturated omega-3 lipids. Either the hybrid 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine or the symmetric 1,2-docosahexaenoyl-sn-glycero-3-phosphocholine were added to the mixture of the naturally abundant 1-palmitoyl-2-oleyl-sn-glycero-3-phosphocholine and cholesterol. Our results indicate that the hybrid and the symmetric omega-3 phospholipids affect the microscopic organization of lipid bilayers differently. Cholesterol does not segregate from polyunsaturated phospholipids and, through interactions with them, is able to suppress the formation of non-lamellar structures induced by the symmetric polyunsaturated lipid. However, this order/disorder balance leads to a bilayer whose structural organization cannot be ascribed to either a liquid ordered or to a canonical liquid disordered phase, in that it displays a very loose packing of the intermediate segments of lipid chains.     

PAN基原丝预氧丝炭纤维微结构的几种新的X射线衍射散射定量表征技术

介绍几种新近开发的针对PAN基原丝、预氧丝和炭丝微结构和结构缺陷的X射线衍射与散射定量表征技术,它们是:纤维材料中柱状(椭球状)纳米取向微孔体积分数X射线小角散射定量表征方法;纤维材料中柱状(椭球状)纳米取向微孔取向角的小角散射定量表征方法;预氧丝中链状相与环化相体积分数的小角衍射定量表征方法以及炭纤维中乱层石墨相与单层石墨相的X射线广角衍射定量表征方法等。     

相对速度对磁流体液体动密封中界面稳定性的影响

推导了旋转轴液体密封中液-液界面由于相对运动引起的切应力,从相对速度角度对液体动密封界面稳定性问题进行了研究,并对结构进行了改进,将磁流体界面的稳定性问题转化为静态扩散处理.     

抽出式风机在治理工作面上隅角瓦斯的应用

针对漳村煤矿综采工作面上隅角瓦斯浓度高的情况,用抽出式风机处理上隅角瓦斯,较好地解决了上隅角瓦斯频繁超限事故,实现了矿井的安全生产。     

Fractal characteristics of electric properties of coal

In the light of fractal geometry theory, the characteristics of coal＇s electric parameters （including dielectric constant, alternating conductivity, dielectric loss angle tangent and electric polarization constant） were studied by using literature data. The results are shown that the electrical properties of coal have fractal characteristic. The fractal dimensions of dielectric, alternating conductivity, dielectric loss angle tangent were obtained, and are relative to the content of pyrite sulfur, heat and ash content of coal.     

一种序分量检测新方法

针对传统dq变换法在检测电网序分量时的不足,提出了一种新的序分量检测方法,该方法不仅适用于负载不对称系统,而且适用于电源电压不对称系统.在检测过程中,不需要采用锁相环(PLL)电路获得同步旋转角,有效消除了PLL延时带来的影响;也不需要进行三角函数计算,降低了算法的复杂度.仿真分析表明,本文所提出的方法在电源电压不对称和畸变时能有效检测出负载电流的正序、负序和畸变分量.     

特厚表土层钻井井壁底的数值计算与试验研究

依据山东万福矿井的地质条件,采用Ansys软件进行削球式井壁底模型计算,提出了最佳圆心角的概念,得出了最佳受力形式削球式井壁底结构.通过模型试验,揭示了井壁底的破坏形式和极限承载力,为今后特厚表土层钻井井壁底的应用提供理论与试验基础.     

同源连杆机构构成特性和传动角的研究

从理论上揭示了原始机构及其同源机构在尺寸型上的内在联系,即它们的确生成了同一条轨迹.还提出,同源机构与原始机构的对应构件有相同的角速度;在通常使用情况下,同源四杆机构与原始四杆机构具有相同的传动角.