X80管线钢中非金属夹杂物的检验及其对钢性能的影响

根据GB／T10561--2005并结合检验实例,介绍了X80管线钢中各种非金属夹杂物的形态及其特征;并分析了夹杂物对钢性能尤其是焊接性能的影响。结果表明：X80管线钢中含有GB／T10561--2005中规定的A,B,C,D及DS各类夹杂物;钢中的夹杂物除了对力学性能和耐腐蚀性能有影响外,对X80管线的钢焊接性能影响也较大。     

SCr420HB钢材D粗夹杂物分析及控制措施

本文针对SCr420HB汽车钢钢材D粗1．5级的质量问题,分析了产生的原因,提出了具体控制措施,使钢材高倍夹杂物Dm级别达到QJ／DT01．13135-2009标准要求。     

闪锌矿中镉、铁的分布特征及其地质意义——以青海锡铁山铅锌矿床为例

文章以青海锡铁山铅锌矿床为例,重点研究了闪锌矿中镉、铁的分布规律,对比分析了主要矿体中闪锌矿、不同矿石类型中闪锌矿、主要载体矿物中闪锌矿及闪锌矿晶体中的镉、铁分布,及其所蕴含的地质意义.从矿物学研究角度提供了矿床初始成矿时赋矿层发生明显倒转的证据,推测了不同矿石类型以及主要载体矿物的成矿温度序列,结合流体包衷体研究,提...     

Towards Sustainable Neighborhoods:The Role of Social Planning in China-A Case Study of Ningbo,Zhejiang Province

This paper argues for a strengthened form of neighborhood planning designed not only to improve the quality of life but also to promote the social inclusion of disadvantaged groups and a more ecologically sustainable development.Empirical focus is the municipality of Ningbo from 1990 onwards,and the most dynamic dimension of this demographic is the net in-flow of rural migrants from across China,and its implications for social policy are traced.The new infrastructure of local governance affords a unique opportunity for a new approach to solving the critical urban problems of ecological sustainability,social inclusion,and quality of life at the neighborhood level.After showing how neighborhood planners might contribute to local initiatives for neighborhood improvement,the paper concludes with some comments on the implications of this approach for planning education.     

SMA490BW耐候钢中析出相和夹杂物的定量统计分析

利用物理化学相分析的方法,结合扫描和透射电镜,研究了SMA490BW耐候钢中析出相和夹杂物的组成、形貌、尺寸信息。相分析结果显示耐候钢中存在富Cu相、M₃C、M(C,N)、非金属夹杂等,其中M₃C在耐候钢中占比为0.868%,M(C,N)占比为0.039 6%;析出相平均尺寸为78.2nm,中间尺寸为51.7nm,小于100nm的约占74%,18～36nm的析出相分布最多,占总量的22.1%。扫描电镜结果显示耐候钢中夹杂物主要有3类:A类(硫化物类)夹杂;DS(单颗粒球状)类夹杂,由Al₂O₃和CaO组成的氧化物夹杂;D_Dup(球状复相夹杂)类复相氧硫化物夹杂。采用透射电镜观察了耐候钢中析出相的形貌,统计了析出相尺寸,结果显示析出相主要是碳氮和铌钛钒组成的化合物,呈圆球状、棒状、不规则形状析出;析出相尺寸从纳米级到微米级,在18～36nm范围分布最多。对比透射电镜和相分析这两种方法对析出相的统计结果,相分析能更精确地统计整个样品区域及跨尺寸范围析出相的分布情况。     

Heat flux field for one spherical inhomogeneity embedded in a functionally graded material matrix

The heat flux field for a single particle embedded in a graded material is derived by using the equivalent inclusion method. A linearly distributed prescribed heat flux field is introduced to represent the material mismatch between the particle and the surrounding graded materials. By using Green’s function technique, an explicit solution is obtained for the heat flux field in both the particle and the graded material. Comparison of the present solution with finite element results illustrates the accuracy and limitation of this solution.     

A test of the extended intergroup contact hypothesis: The mediating role of intergroup anxiety, perceived ingroup and outgroup norms, and inclusion of the outgroup in the self.

S. C. Wright, A. Aron, T. McLaughlin-Volpe, and S. A. Ropp (1997) proposed that the benefits associated with cross-group friendship might also stem from vicarious experiences of friendship. Extended contact was proposed to reduce prejudice by reducing intergroup anxiety, by generating perceptions of positive ingroup and outgroup norms regarding the other group, and through inclusion of the outgroup in the self. This article documents the first test of Wright et al.'s model, which used structural equation modeling among two independent samples in the context of South Asian-White relations in the United Kingdom. Supporting the model, all four variables mediated the relationship between extended contact and outgroup attitude, controlling for the effect of direct contact. A number of alternative models were ruled out, indicating that the four mediators operate concurrently rather than predicting one another. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanical property analysis of Nitinol defective stent under uniaxial loading/unloading

The vascular stents are important medical devices introduced into a vessel to protect the lumen from unfriendly stenosis. However, Nitinol stent is easy to fail in practice. The present paper focuses on the influence of defects on its mechanical behavior by finite element analysis. The essential stent cell is used with two different type of defects, which includes the face bulge defect resulted from laser burrs or TiC inclusion arises and C‐contained particle voids. Auricchio’s super‐elastic consititutive equations are used in the finite element simulations. It is found that the stress distribution is not only related to the defect type but also to the defect position. With the increasing distance from the TiC defect to the knot’s notch, the influence of defects on stress distribution of stents becomes small. For void defects, those near both the inner fillet and the outer fillet have grand influence on the stent’s global stress distribution. In particular, the higher stress concentrations are undergone near knot’s defects. For all models, the maximum Martensite Volume Fraction is near knots. The finite element analysis shows that cracks/fractures can easily appear near knots. A stent with a TiC inclusion or void defect is likely to fail. All obtained conclusions can be useful to design against stent premature mechanical failure.     

不同应力解除法地应力测试方法对比及工程应用

介绍了钻孔空心包体式应变计与孔壁切缝解除法地应力测试的基本原理和测试方法,同时对两种应力解除地应力测试方法的适用性进行对比分析。将两种应力解除法应用于锦屏一级导流洞边墙的地应力测试中,并就同一钻孔进行了对比测试。通过对测试结果的对比分析可知,两种方法的测试结果相符,应力量值误差均小于20%,钻孔横截面最大主应力方位误差也在20°以内。鉴于孔壁切缝解除法地应力测试方法可用于极高应力条件下的应力测量,对于西部的深埋高-极高应力条件下的地下工程来说,该方法非常行之有效。     

盐水包裹体在成岩作用研究中的应用--以塔河油田下奥陶统碳酸盐岩为例

该文根据塔河油田下奥陶统碳酸盐岩盐水包裹体观察测试资料,对其类型和特征进行了描述,并结合地质分析,重点讨论了盐水包裹体在塔河油田下奥陶统碳酸盐岩成岩作用中的应用.研究表明,除了利用传统的显微镜观察、阴极发光、扫描电镜等分析手段外,利用盐水包裹体所记录的成矿流体信息可以进一步探讨成岩作用,从而为储层预测与研究提供依据.