摘要：The driving force for using powder metallurgy(PM)mostly relies on its near net-shape ability and cost-performance *** automotive application is a main market of PM industry,requiring parts with competitive mechanical or functional performance in a mass production *** the automobile technology transforms from traditional internal combustion engine vehicles to new energy vehicles,PM technology is undergoing significant changes in manufacturing and materials *** review outlines the challenges and opportunities generated by the changes in the automotive technology for ***-cost,high-performance and light-weight are critical aspects for future PM materials ***,the studies on PM lean-alloyed steel,aluminum alloys,and titanium alloy materials were *** addition,PM soft magnetic composite applied to new energy vehicles was *** new opportunities for advanced processing,such as metal injection molding(MIM)and additive manufacturing(AM),in automotive industry were *** general,the change in automotive industry raises sufficient development space for ***,emerging technologies require more preeminent PM ***-based parts are still the main PM products due to their mechanical performance and low *** will occupy the growing market of highly flexible and complex *** opens a door for fast prototyping,great flexibility and customizing at low cost,driving weight and assembling reduction.

摘要：烧结过程控制对粉末冶金整个工艺过程起着至关重要的作用,控制不好,将导致烧结后的零件在尺寸和性能上不稳定或达不到产品设计要求,并可能还会出现氧化、脱碳、渗碳、崩裂和积碳等工业中常见的问题。随着对粉末冶金产品的性能和成本控制要求不断提高,金属Cr因其价格低并具有很好的强化效果,成为粉末冶金工业开拓的重点方向。但是金属Cr容易氧化,对烧结气氛要求较高,因此对烧结工艺提出了挑战。随着烧结炉技术的发展和氮基保护气体广泛使用,在网带炉中烧结含Cr成分的零件已经成为现实。利用热电偶、氧分压和CO分析仪等设备组成的分析系统,评估了以氮氢混合气体作为保护气氛的网带烧结炉的实际烧结情况,分析了几种烧结过程中常见的缺陷及其原因,并提出了相应的改善措施,同时也总结了含Cr材料所需的烧结条件及其控制。

摘要：针对目前小型燃煤工业锅炉排烟温度高、排烟热损失大,用户管理和操作水平低,运行中通常间断式给水的情况,设计了两种利用烟气余热进行节能改造的无压装置。在锅炉运行时,通过无压换热器的换热、水箱中水的蓄热来降低排烟温度、提高锅炉效率。改造后的锅炉在稳定工况、低负荷工况下的测试结果证明,锅炉效率均显著提高。回收周期的计算表明,应用该技术投资少、回收周期短。

摘要：For most organisms,molecular oxygen is indispensable for normal physiological metabolism;in humans,prolonged hypoxia in tissues can induce many diseases,exemplified by cardiovascular disease,chronic wounds,and tissue ***,the oxygen in our environment is vital for *** a main source of oxygen in the natural world that transforms light energy into chemical energy and oxygen,photosynthesis has been widely studied in scientific research and used in production of food,fuel,and *** recent years,photosynthesis has become more closely involved in biomedicine and has been widely used in photodynamic therapy,tissue regeneration,transplantation,and in treatment of specific *** review summarizes innovative applications of photosynthesis in biomedical research and highlights the theory and implications of clinical treatment for specific diseases.

摘要：以聚四氢呋喃、异佛尔酮二异氰酸酯、蓖麻油为主要原料,热水解木质素为改性剂,2,2-二羟基甲基丙酸为亲水扩链剂,采用预聚体法制备了一系列的木质素改性蓖麻油基水性聚氨酯(LCWPU)。考察了LCWPU胶膜的结构特征、热性能、疏水性以及光泽度。探讨了木质素的含量及n_(NCO)/n_(OH)对LCWPU胶膜热稳定性能、力学性能和耐水性能的影响。结果表明,随着木质素含量的增加以及n_(NCO)/n_(OH)的增加,LCWPU胶膜的吸水率降低,拉伸强度显著提高;当木质素含量为3%,且n_(NCO)/n_(OH)为4.5时,LCWPU胶膜的耐水性及拉伸强度最高,接触角可达95.7°,吸水率为14.3%,拉伸强度为62.9 MPa,断裂伸长率为297.5%。所设计的木质素改性蓖麻油基水性聚氨酯在皮革涂饰剂、哑光木漆等领域具有良好的应用前景。

摘要：Laser additive manufacturing technology with powder feeding was employed to repair wrought Ti17titanium alloy with small surface *** microstructure,micro-hardness and room temperature tensile properties of laser additive repaired(LARed)specimen were *** results show that,cellular substructures are observed in the laser deposited zone(LDZ),rather than the typicalαlaths morphology due to lack of enough subsequent thermal *** cellular substructures lead to lower micro-hardness in the LDZ compared with the wrought substrate zone which consists of duplex *** tensile test results indicate that the tensile deformation process of the LARed specimen exhibits a characteristic of dramatic plastic strain heterogeneity and fracture in the laser repaired zone with a mixed dimple and cleavage *** tensile strength of the LARed specimen is slightly higher than that of the wrought specimen and the elongation of11.7%is lower.

摘要：本文介绍了秦山一期棒控棒位系统数字化设计,包括系统主要功能、系统结构、软件设计流程,以及触摸屏的设计等。详细论述了软件设计调试过程中碰到的一些问题,分析问题并给出相应的解决方法。

摘要：随着对空间信息获取能力的要求不断提高,使得高分辨率动态遥感成为空间光学领域一个新的研究热点。偏视场同轴三反光学系统具有长焦距、体积小、轻量化程度和成像质量高等特点,能够满足低轨视频卫星高分辨率、多谱段、多功能性和低成本的要求,因此在高分辨率动态遥感领域有着广泛的应用前景。以高斯光学和三反射消像差理论为基础,设计了可见光面阵成像、近红外和中红外线阵推扫成像的共孔径光学系统。可见光系统焦距4.1 m,近红外系统焦距2.6 m,中红外系统焦距1.85 m,三者孔径均为520 mm,视场均为0.6°×0.6°,成像质均接近衍射极限,成像质量良好。系统总长小于f′_(visible)/3.7,且系统的加工和装配公差较为宽松,易于实现。

摘要：太原国海广场主楼高303.9m,通过抗震超限审查时是山西省规划建设的最高建筑。主楼采用钢管混凝土框架-钢筋混凝土核心筒混合结构体系,沿结构高度方向布置了5道环带桁架,并对多种设计方案进行对比。针对结构多项指标超限情况,采用了基于性能化的抗震设计方法。采用多种软件进行结构整体及局部的计算分析,包括小震反应谱及弹性时程分析、中震抗震性能计算、大震弹塑性时程分析与性能评估、典型楼层楼板应力分析、关键节点承载力数值分析,计算结果均能够达到预设的抗震性能目标。

摘要：针对人机界面布局评价中缺乏对用户视觉认知特征的量化研究问题,提出一种考虑人体视觉认知特征的虚拟博物馆界面布局美度评价方法。首先,选取对称度、密集度、简洁度、次序度、优势度作为美度评价指标,以抽象后的矩形布局图像为样本进行界面布局美度评价;其次,采用眼动追踪技术对界面布局美度进行实验测试,进行用户视觉认知生理数据结果的获取;再次,基于灰色理论构建改进的灰色H-凸关联模型,量化用户视觉认知与人机界面布局美度之间的映射关系;最后,将提出方法应用于虚拟博物馆人机界面布局设计方案分析中,验证了评价方法的有效性和其对界面布局美度指标正负关联性的判断能力。