Al-4%Cu过饱和合金在强磁场中时效行为

采用差示扫描量热仪分析并结合显微硬度测试、电子探针分析、透射电镜观察研究了10-T稳恒强磁场对Al-4％Cu（质量分数）合金130℃时效过程中各沉淀相析出行为的影响。结果表明：在低温时效初期强磁场的引入加速了铜的扩散，降低了G.P.（Ⅰ）区的溶解激活能，促进其溶解，各沉淀相的析出与溶解温度均向低温处移动，时效进程加快；另外，强磁场时效后沉淀相尺寸减小；施加强磁场试样的硬度明显高于未施加磁场试样的，时效硬化效果加强。     

微量Si在W—7Ni—3Fe重合金中的行为

研究了掺到原料Ｗ粉中微量Ｓｉ（４００ｐｐｍ）在Ｗ－７Ｎｉ－３Ｆｅ重合金中的分布及在液相烧结过程中的行为。结果表明，Ｓｉ主要以固溶形式分布在Ｗ晶粒中。Ｘ射线光电子能谱（ＸＰＳ）分析发现，在掺杂Ｓｉ的Ｗ－Ｗ及Ｗ－基体相界面富集ＳｉＯ２和Ｎａ２ＳｉＯ３在未掺杂试样的断口表面发现了较弱的ＷＯ２的ＸＰＳ谱，而在掺杂合金中未发现ＷＯ２。     

TiO_2对ZrO_2－NiCr金属陶瓷烧结特性和相稳定性的影响

本文研究了ＴｉＯ２掺入对ＣａＯ稳定ＺｒＯ２（简称ＣａＳＺ－ＮｉＣｒ）金属陶瓷烧结特性的影响，测定了ＣａＳＺ－ＮｉＣｒ－ＴｉＯ２金属陶瓷烧结样品的密度和显微硬度，结果表明，ＴｉＯ２的掺入能提高ＣａＳＺ－ＮＩＣｒ金属陶瓷的烧结密度和显微硬度，对ＣａＳＺ－ＮｉＣｒ金属陶瓷有助烧结作用．金相观察表明，ＴｉＯ３的掺入改变了ＮｉＣｒ相在金属陶瓷中的形貌，说明了ＮｉＣｒ与ＣａＳＺ的浸润性有一定的改善．ＸＲＤ和ＥＰＭＡ分析结果显示，ＴｉＯ２偏聚在ＮｉＣｒ金属相中，不影响ＣａＳＺ的稳定性．     

基于用户兴趣度的校园网带宽管理策略应用研究

针对校园网出口拥塞问题,提出一种基于行为分析的用户兴趣建模方法,通过用户参与时间来衡量并计算不同种类应用的用户访问兴趣度,在用户兴趣度的基础上结合通道管理技术进行带宽管理策略研究,实现动态带宽管理。实施结果表明,该方法能够有效地提高用户的网络满意度。     

引入关联分析的用户行为信任评估在云计算平台中的研究

关联规则是数据挖掘的重要方法。随着国内外云计算应用及研究的不断推进,云计算的安全性成为云计算的核心问题之一。通过进行用户的状态行为关联分析,提取信任信息,结合可信云的思想,提出一个云计算下基于信任的防御系统模型。     

Poly(oxyphosphazenes): A unifying look at structure and morphology

Variations in thermotropic behavior have been investigated for many crystalline polyphosphazenes. Experimental results obtained from DSC, solid-state MAS NMR, dilatometry, mechanical property (creep and dynamic) measurements, birefringence, X-ray (wide and small-angle), and electron diffraction have been made as a function of temperature in an attempt to elucidate the structure-morphology behavior in these polymers. Initially all polyphosphazenes described in this study crystallize from dilute or moderately concentrated solutions in the monoclinic form with relatively low crystallinity (50%). When heated, these specimens expand atT(1) and adopt a chain-extended 2D mesophase morphology in order to relieve congestion. Above this first-orderT(1) temperature a chain-extended –P=N– chain backbone morphology transforms into an isotropic phase at the melting temperatureT _m. When cooled, samples transform into the mesostate. However, crystallization from the mesophase belowT(1) takes place into a 3D orthorhombic state. These two modes of ordering/disordering are in accordance with (i) a hexatic chain packing [betweenT(1) andT _m] with variously mobile side groups that also exhibits smectic features when mesogenic side groups are present and (ii) a 3D orthorhombic structure of high crystallinity belowT(1). The initial monoclinic phase is accessible only via a solution crystallization route. Solid-state MAS NMR, crystallization kinetic measurements, and optical microscopy studies obtained from oriented and unoriented polymers have been especially germane in providing a unifying picture for mesophase formation and ordering in polyoxyphosphazenes. X-ray and electron diffraction evidence is complicated by critical overlapping peaks that are found under these same conditions. They demonstrate that (a) positional disorder exists along the chain direction and (b) the side chain above, as well as below, theT(1) transition is governed by the mobility, size, and type of side group in circumstances where phase transformations occur.     

基于Virtools的虚拟现实技术及在特种设备教学中的应用

本文以电梯为研究对象,运用虚拟现实技术建立电梯虚拟样机,开发了一种电梯零部件识别系统用于电梯司机的考核。现行的考核方式存在过程繁琐、成绩统计困难等问题,就这些问题提出了合理的解决方案,并将方案应用于开发的系统中。该系统是虚拟现实技术在特种设备领域的全新应用,构建的虚拟电梯完整地呈现了真实的电梯,而且可以从多角度观察其结构的每个细节,方便教学与考核。系统结合SolidWorks、3Dmax、Virtools等软件,以触摸选择为主要的操作方式,具有优良的操作性与交互性,且投资少、开发周期短。     

Microhardness and corrosion behavior in CrN/electroless Ni/mild steel complex coating

The electroless nickel–phosphorous (Ni–P) coating was chosen as an interlayer to improve the properties of the CrN/mild steel (MS) composite. A hypophosphite-reduced acid solution was used to first deposit electroless Ni–P onto MS substrates, and then the CrN overlayer was deposited by reactive r.f. magnetron sputtering onto the electroless Ni–P modified substrate. The electroless Ni–P layer crystallizes with the precipitation of a Ni₃P phase during r.f. sputtering, and thus a coating–substrate composite of CrN/Ni–Ni₃P/MS is formed. The electroless Ni–P coating increases the surface hardness of the steel substrate to more than three times. The surface hardness of the CrN coating modified by an electroless Ni–P interlayer exhibits a hardness higher than 2000 HK_0.015. The usual substrate effect on the microhardness of the coatings is nearly eliminated with the complex coating feature, and a significant enhancement of surface hardness in the coating assembly is achieved. The corrosion tests indicate that the Ni–Ni₃P/MS configuration exhibits a more positive E_corr value (i.e. less electronegative) than CrN/MS and the corresponding potential curve is shifted toward the low-current side, indicating a better anti-corrosion performance. Through comparison of the E_corr values and the polarization curves, it is demonstrated that the CrN/Ni–Ni₃P/MS composite exhibits significantly higher corrosion resistance than the Ni–Ni₃P/MS and CrN/MS coating configurations.     

加载速率对结构钢力学性能和断裂韧度的影响

在常温下进行了常用建筑结构钢(16Mn和Q235B钢)动态拉伸和动态断裂韧度试验。试验结果表明，材料在动载下无论是屈服强度还是抗拉强度均有一定的提高，塑性有了一定的降低；由于缺口尖端区域温度的升高，常温下动载对于16Mn钢母材和焊缝的断裂韧度是有利的；Q235B钢常温下，焊缝的断裂韧度值较低，且动载对母材的断裂韧度影响较大，和静载相比动载下断裂韧度值降低了4倍有余，可以看出，Q235B钢的抗震性能较差。通过研究发现，对于低韧度水平的材料，研究动载下结构的断裂行为时．材料的强度也应该作为一个考虑因素。     

基于行为安全2-4模型的大众滑雪事故行为原因分析

运用文献资料、数理统计等方法,以行为安全2-4模型分析53例大众滑雪事故的行为原因,并构建模型。结果：滑雪者未能保持安全距离、滑雪场工作人员未尽到安全保障义务,是引发滑雪事故发生最多的一次性不安全行为;滑雪场防护网是引发事故频次最高的不安全物态;滑雪者未保持安全距离是事故发生最多的习惯性行为。滑雪场安全管理体系欠缺主要表现在滑雪场员工安全操作规程欠缺。