汽车用冷轧双相钢的生产工艺及组织性能特征

介绍了冷轧双相钢的生产方法以及国内外生产发展概况。分析了冷轧双相钢的合金成分特点、显微组织特征、力学特性与主要工艺控制要点,并对我国双相钢的生产与发展提出了建议。     

基于AP聚类的不完整大数据填充

不完整数据的分析与填充一直是大数据处理的热点研究课题,传统的分析方法无法对不完整数据直接聚类,大部分方法先填充缺失值,然后对数据聚类。这些方法一般利用整个数据集对缺失数据进行填充,使得填充值容易受到噪声的干扰,导致填充结果不精确,进而造成聚类精度很低。提出一种不完整数据聚类算法,对不完全信息系统的相似度公式进行重新定义,给出不完整数据对象间的相似度度量方式,进而直接对不完整数据聚类。根据聚类结果将同一类对象划分到相同的簇中,通过同一类对象的属性值对缺失值进行填充,避免噪声对填充值的干扰,提高填充结果的精确性。实验结果表明,提出的方法能够对不完整数据进行聚类,并有效提高缺失数据的填充精度。     

基于Web Services的工作流管理系统的研究与应用

首先介绍了基于WebServices的工作流管理系统的应用框架,提出了系统的概念模型和实现模型,并重点讨论了工作流层、服务层和消息层的实现技术。该系统具有较好的扩展性和跨平台性,能够有效地应用于企业中平台异构、语言异构的应用环境。     

用于密码芯片的前馈异或安全扫描结构

扫描结构在给密码芯片增加可测性的同时也可能被不当使用为旁路攻击路径,使密码芯片的密钥信息泄露.为解决这个问题,提出一种前馈异或安全扫描结构.首先将异或安全扫描寄存器引入扫描结构中,该结构对测试图形进行输入?输出线性变换,实现对测试图形的硬件加密;然后分析了该结构的安全性并给出其测试图形生成算法.实验结果表明,文中提出的安全扫描结构能抗击基于扫描结构的旁路攻击和复位攻击,并保留了传统扫描结构的高测试覆盖率.     

ZIF-67原位负载纳米纤维素基锂离子电池隔膜的制备及性能研究

本研究以纳米纤维素（CNF）为原料,经乙酰化、原位负载ZIF-67和浸渍电解液制备出一种新型ZIF-67@乙酰化纳米纤维素（ZIF-67@ACNF）锂离子电池隔膜,系统探讨了ZIF-67的粒径对隔膜结构及性能的影响。结果表明,当ZIF-67的粒径从0.46 μm（ZIF-67₄@ACNF隔膜）减小至0.25 μm（ZIF-67₈@ACNF隔膜）时,隔膜的孔隙率从74.2%减小至52.1%,离子电导率从0.75 mS/cm下降至0.22 mS/cm,界面电阻从112.5 Ω增加至1 115.7 Ω,锂离子迁移数从0.41减小至0.31,电化学稳定窗口从5.1 V减小至4.5 V。采用ZIF-67₄@ACNF隔膜组装电池,在室温、0.5 C的条件下进行电池充/放电测试,初始容量达到159.6 mAh/g,循环200圈后容量保持率达到90%。     

聚丙烯酸类共聚物/SiO2硅织物有机-无机杂化材料的合成与表征

以γ缩水甘油氧丙基三甲氧基硅烷为偶联剂,通过溶胶-凝胶法制备了聚丙烯酸类共聚乳液/SiO2硅织物的有机-无机杂化材料,利用FT-IR、SEM、DSC及TG等手段对其进行了结构表征.SEM照片显示有机组分与无机组分间分布较均匀,并出现了相互贯穿;DSC表明Tg为206℃;对比法测得的比表面为81.61m2/g.实验结果证实该硅织物杂化材料中存在-Si-O-C-共价键,热稳定性较好.     

The influence of surface oxide on the growth of metal/semiconductor nanowires

We report the critical effects of oxide on the growth of nanostructures through silicide formation. Under an in situ ultrahigh vacuum transmission electron microscope, it is observed from the conversion of Si nanowires into the metallic PtSi grains epitaxially through controlled reactions between lithographically defined Pt pads and Si nanowires. With oxide, instead of contact area, single crystal PtSi grains start forming either near the center between two adjacent pads or from the ends of Si nanowires, resulting in the heterostructure formation of Si/PtSi/Si. Without oxide, transformation from Si into PtSi begins at the contact area between them, resulting in the heterostructure formation of PtSi/Si/PtSi. The nanowire heterostructures have an atomically sharp interface with epitaxial relationships of Si(20-2)//PtSi(10-1) and Si[111]//PtSi[111]. Additionally, it has been observed that the existence of oxide significantly affects not only the growth position but also the growth behavior and the growth rate by two orders of magnitude. Molecular dynamics simulations have been performed to support our experimental results and the proposed growth mechanisms. In addition to fundamental science, the significance of the study matters for future processing techniques in nanotechnology and related applications as well.     

A Prediction Region‐based Approach to Model Uncertainty for Multi‐response Optimization

Multi‐response optimization methods rely on empirical process models based on the estimates of model parameters that relate response variables to a set of design variables. However, in determining the optimal conditions for the design variables, model uncertainty is typically neglected, resulting in an unstable optimal solution. This paper proposes a new optimization strategy that takes model uncertainty into account via the prediction region for multiple responses. To avoid obtaining an overly conservative design, the location and dispersion performances are constructed based on the best‐case strategy and the worst‐case strategy of expected loss. We reveal that the traditional loss function and the minimax/maximin strategy are both special cases of the proposed approach. An example is illustrated to present the procedure and the effectiveness of the proposed loss function. The results show that the proposed approach can give reasonable results when both the location and dispersion performances are important issues. Copyright © 2015 John Wiley & Sons, Ltd.     

CSP工艺热轧低碳钢板的强化机制

采用金相显微镜、H—800透射电镜和正电子湮没方法分析了CSP热轧低碳钢板金相组织、析出物形貌、尺寸、分布及位错密度。结果表明:CSP工艺热轧低碳钢板的晶粒较为细小,约为5.3μm;当累积变形量较小、变形温度较高时,析出物主要在晶界上,数量少见比较粗大,其尺寸大多大于150nm;当累积变形量较大、变形温度较低时,析出物主要在晶内,细小、弥散且数量较多,其尺寸大多为20～100nm,析出物主要为Al_2O_3、MnS或Cu_7S_4;随着累积变形量的增加,位错密度明显增加,终轧后轧件的位错密度约为6.35×10~(14)m~(-2)。晶粒细化、析出物弥散分布及位错密度增加是CSP工艺热轧低碳钢板强度高的决定因素。