面向异构超算的结构分析高效并行计算方法

In order to exploit the efficient computing power of many integrated cores on heterogeneous cluster, a multi-level and multi-granularity collaborative parallel computing method is proposed for finite element structural mechanical analysis. Computing tasks are divided into three levels: inter-node parallelism, inter-device parallelism and inter-core parallelism. Through mapping decomposablecomput- ing jobs to different hardware layers of heterogeneous MIC system, the proposed method not only effectively resolves the load balancing problem between CPU and MIC devices, but also significantly reduces the communication overheads of the system. Different engineering simulation case experiments for large scale parallel computing were conducted on “Tianhe 2” supercomputer. Up to 39000 CPU+MIC cores were employed and the finite element size of the analysis was more than 100 million units. Test results show that the proposed method can achieve good speedup and parallel computing efficiency in large scale parallel computing of finite element structural analysis. The optimized adaptation of finite element structural analysis and heterogeneous MIC computing platform is realized, which can provide reference for parallel porting and performance optimization of similar applications.     

耐高温、低导热、韧性中空陶瓷微珠复合材料的制备及其性能

在高速飞行的过程中飞行器温度急速上升,飞行器舱段间的密封材料不仅要具有优异的耐高温性能,同时要具有较低的导热系数辅助参与阻隔舱段间的热量传递,并且要具有优异的力学性能使其不被破坏。以中空陶瓷微球为骨料,加入酚醛树脂及磷酸盐固化体系制备有机/无机杂化耐高温韧性复合材料,并对复合材料进行高温处理,研究复合材料在高温处理前后的变化。通过力学性能测试、SEM观察以及XRD和FT-IR测试对复合材料高温处理前后的抗压强度、压缩形变能力、微观结构以及组分变化进行表征,并通过火焰燃烧对复合材料耐高温性能进行测试。结果表明,所制备的复合材料具有较高的抗压强度以及优异的韧性,1 000℃高温处理600 s复合材料的宏观形貌未受到影响,具有较高的热稳定性。导热系数测试结果表明,中空陶瓷微珠含量的增加、酚醛树脂的添加以及高温处理均会导致复合材料导热系数降低,最低的导热系数低至0.16 W/(m·K)。     

纤维增强石英复合材料的改性处理及性能研究EI北大核心CSCD

采用气相接枝方法对纤维增强石英复合材料进行改性处理,对材料的微观形貌、比表面积、介电性能、力学性能和吸湿率等进行测试和分析。结果表明,改性处理和后续热处理对材料的微观形貌和比表面积影响很小,且对材料的介电性能和力学性能没有损伤。改性处理后,材料的介电损耗随频率的变化范围从4.7×10^-3~6.8×10^-3明显降低到1.7×10^-3~2.9×10^-3,拉伸强度从48.58 MPa明显提高到63.49 MPa。改性处理的优选处理条件为(T bp+30℃)/72 h/80%M。材料的极限吸湿率在改性处理后从6.35%降低到0.32%,说明该方法具有优异的防潮效果。     

流行杀毒软件快速扫描

Norton AntiVirus 2001中文版 Norton AntiVirus 2001中文版能够全面抵御ActiveX及Java Applet的恶意程序,具有自动病毒保护,能防止病毒、特洛伊木马等恶意程序入侵,其LiveUpdate自动取得新的病毒和病毒定义码,进行更快速且更有效的软件升级。 金山毒霸2001 采用嵌入式查杀技术:嵌入Office和IE内部,和应用软件融为一个整体,及时拦截来自Office2000、Office XP和IE的各种宏病毒及互联网病毒。具有     

车道被占用对城市道路通行能力的影响

车道被占用是当今社会中一个非常普遍的现象,会对道路的实际通行能力产生严重影响。其影响因素有车道宽度、路段通道数、交通管理等。该文着重分析了因事故车辆对不同行车道的占用、单向车道宽度、上游车流量、交叉口信号控制灯等因素对道路通行能力的影响,采用了停车线法对十字交叉口进行分析,构造函数模型求解不同占道情况下的通行能力。通过建立排队系统模拟仿真交通车辆排队,搭建模型模拟交通流动力特性。     

5-氨基-2-溴苯甲酸的合成

5-氨基-2-溴苯甲酸是一种重要的有机合成原料。本文以2-溴苯甲酸为原料,经硝化、还原制备标题化合物,结果较好。     

子长北部地区盒8段储层成岩作用研究

应用了普通薄片、铸体薄片、扫描电镜等多种测试手段对研究区盒8段砂岩的成岩作用及其对储层的影响等做了分析说明.认为:研究区储层主要为岩屑石英砂岩,几乎不含或者含极少量的长石;压实作用是造成砂岩储层孔隙丧失的主要原因之一,而胶结作用加剧了原生孔隙的进一步减小,尤其是碳酸盐胶结,其次是石英加大边和高岭石;但绿泥石膜胶结物的存...     

沥青路面废料冷再生利用试验分析

为了研究沥青路面旧料的性能特点及冷再生技术的可靠适用性,进行了旧料的性能试验分析和以水泥为添加剂的冷再生混合料性能的室内强度试验.试验结果表明:分析旧沥青混合料中沥青和集料性能变化规律可对再生混合料合成级配及添加剂的确定提供依据;在旧料中掺入不同剂量的水泥添加剂和适量的水之后,旧混合料的性质得到改善,提高了旧混合料的抗压强度.研究结果可为冷再生技术的应用提供依据.     

Preparation and characterization of SrTiO<Subscript>3</Subscript> thin film on functional organic self-assembled monolayers

SrTiO₃ thin film was successfully prepared on the functionalized organic self-assembled monolayers (SAMs) by the Liquid Phase Deposition (LPD) method. The as-prepared samples were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM) and metallographic microscope. Measurement of contact angle showed that the hydrophobe substrate was changed into hydrophile by UV irradiation. AFM photographs of octadecyl-trichloro-silane self-assembled monolayer (OTS-SAM) surface approved that UV irradiation did change the morphology of OTS monolayer and provided evidence for the conversion of hydrophilic characteristic. Photographs of Metallographic Microscope showed that OTS-SAM had an active effect on the deposition of SrTiO₃ thin film. XRD and SEM indicated that the thin film was of pure cubic phase SrTiO₃ and composed of nanosized grains with a size in the range of 100–500 nm. The formation mechanism of the SrTiO₃ film was proposed.     

微型轴承浮动浪型保持架

为了解决微型轴承浪型保持架由于轴承力矩均匀性差，使用中常被卡死的问题，采用上下两半保持架压爪时留有一定间隙。使之轴向和径向可以自由活动的浮动议型保持架、其上下两半保持架工作时处于自由浮动状态，可以自动调整保持架与球之间的作用力；采用内圈外径引导，大大减少了载荷区内钢球和保持架作用力的变化幅值。附图7幅，表2个，参考文献4篇。