铁路运输安全报警系统

本文介绍利用铁轨的振动检测来往火车及其与测量点的距离，以便使在段内施工人员及时扯离，或铁路与公路交叉处放下栏杆确保铁运安全的报警系统。     

膜基组件的微硬度量测与膜体力学参数的顺序辨识

本文采用量纲分析得到膜基组件微硬度量测的若干标度律,并在分阶段辨识模型下应用轴对称弹塑性有限元计算对膜体的力学参数(弹性模量、屈服应力)进行了顺序辨识。     

重力流沉积的机械分异作用

阐明了在现代地面上实际观察到的陡坡碎屑物质重力分异作用，讨论了辽河西部凹陷沙三段陡坡重力流、缓坡重力流、湖底扇和重力流水道４种不同类型的重力流沉积分异规律．分析认为，重力流沉积体系中仍发生重力分异作用，不同类型重力流沉积的分异作用特点不同．陡坡粗碎屑重力流沉积分异作用不甚明显，而缓坡重力流和湖底扇沉积分异作用明显．这对于丰富和发展陆源碎屑沉积分异理论、指导油田勘探和开发具有重要意义．     

吸入式气浮净化机机械性能研究

在实验室模拟装置上对吸入式气浮净化机的机械性能进行了研究,主要考察了不同形式转子的工作性能、全风压与吸气量的关系、气泡大小、浮选室中流体动力学特性及液体在浮选机中的停留时间分布。研究结果表明,六叶转子优于八叶和四叶转子,全风压与吸气量具有定量关系,转速及气量对气泡大小没有明显影响,浮选定中存在气体通道、液体循环通道、两相混合区、浮选区、泡沫区等几个区域,液体在浮选机中的流动可用停滞区和多釜串联组合流动模型予以表征。     

Low temperature spark plasma sintering of TC4/HA composites

Ti6Al4V/hydroxyapatite composites(TC4/HA) have been prepared by high energy ball milling and low temperature spark plasma sintering at 600 °C, 550 °C, 500 °C and 450 °C, respectively. The sintering temperature of the composites was sharply decreased as the result of the activation and sur fi cial modi fi cation effects induced from high energy ball milling. The decomposition and reaction of hydroxyapatite was successfully avoided, which offers the composites superior biocompatibility. The hydroxyapatite in the composites was distributed in gap uniformly, and formed an ideal network structure. The lowest hardness, compressive strength and Young's modulus of the composites satisfy the requirements of human bone.     

Cu-(B4C)p metal matrix composites processed by accumulative roll-bonding

In this study, Cu/B4C metal matrix composites were prepared by accumulative roll-bonding (ARB). The microstructure of the processed samples was characterized by TEM, SEM and optical microscopy. The microhardness, uniaxial tensile and four-point probe tests were carried out to evaluate the mechanical properties and electrical resistivity of the ARBed monolithic and composite samples. The results showed that the reinforcement distribution was improved by increasing ARB cycles, which was quantitatively confirmed by some models. Based on TEM observations, the formation of an ultrafine grained structure in the composite matrix was also approved. It was shown that with increasing ARB cycles, the microhardness and tensile strength of the monolithic Cu samples were enhanced up to the 3rd cycle and then saturated, but the microhardness and tensile strength of the composites showed an increasing trend to the last cycle. Apart from a substantial improvement in the mechanical properties of the Cu/B4C composites, a minor decrement in electrical conductivity was detected after six ARB cycles.     

Effect of long-period stacking ordered phase on microstructure, mechanical property and corrosion resistance of Mg alloys: A review

Magnesium alloys containing long period stacking ordered (LPSO) phase have been received a great deal of attention in the last decade owing to their excellent comprehensive properties of mechanical strength and corrosion resistance. In this paper, some fundamental aspects of LPSO containing Mg alloys have been reviewed, including: (1) microstructural characterization, formation conditions and the associated phase transformation of LPSO phases in Mg alloys; (2) deformation mechanism of LPSO phases and their influence on the deformation mechanism of the Mg matrix; (3) effect of LPSO structure on the mechanical performance such as tensile strength, creep resistance, fracture toughness and fatigue strength; (4) corrosion behavior of LPSO containing Mg alloys and their possible applications as the biomaterials. Moreover, some remaining unsolved issues of the LPSO containing Mg alloys and the future target about how to further improve their service properties have been also described.     

培养读图能力 提高工程意识

读图是工程技术人员必备能力之一,工程图学就是研究绘制和阅读工程图样的一门基础课,其中切割类组合体视图的读图是难点之一.通过实例介绍了切割类组合体视图的判断和读图方法,以利于提高工科大学生的读图能力和工程意识.     

车身工程图精确矢量化圆的自适应算法

在车身薄膜图扫描图像细化的基础上，提出了一就业有确矢量化圆的算法，讨论了在选取任意初始点后，根据初点的坐标，适当调整其余两个点的位置，以使这三点尽量反映圆的特征，从而精确获得圆的特征参数，给出了以不同半径的标准圆进行测试的结果和以桑塔纳轿车前纵梁加强板为例进行的工业应用，结果表明，该算法是稳定、准确的。