基于有限元分析的金刚石钻头强度验算公式

在对81／2B125金刚石钻头进行有限元计算分析后，找出最大应力点在金刚石钻头冠部切削告处。通过改变各相关尺寸和结构型式，用有限元法模拟试验过程，在给定结构参数和工艺参数情况下获得多组数据。根据专业知识，参考有限元计算获取的各组数据变化特征，选出拟合较好的公式类型，再采用回归分析方法确定待定系数，最后得出工程上实用的金刚石钻头强度验算公式。用这个公式对81／2B461W和121／4B331金刚石钻头进行了强度验算，经改进设计后钻头在现场使用取得了良好的效果。     

HSLA-80/100钢的焊接

对ＨＳＬＡ－８０／１００钢的焊接性、焊接材料及焊接工艺进行了综述，并指出了现存在的主要问题。     

Contact with out-group friends as a predictor of meta-attitudinal strength and accessibility of attitudes toward gay men.

Two studies examined the effects of cross-group friendships on heterosexuals' attitudes toward gay men. In Study 1, the authors tested the effects of cross-group friendships with gay men on out-group attitudes, meta-attitudinal strength, and attitude accessibility. The authors simultaneously explored mediational effects of intergroup anxiety. Path analysis showed that cross-group friendships were associated with meta-attitudinally stronger and more accessible out-group attitudes, and the effects on all 3 criterion variables were mediated by intergroup anxiety. In Study 2, the authors sought to replicate the basic results of Study 1, while additionally exploring mediational effects of closeness of cross-group friendship and moderational effects of perceived group typicality. Structural equation modeling showed that cross-group friendships were associated with meta-attitudinally stronger and more accessible out-group attitudes; friendships had indirect effects on all 3 criterion variables, via closeness of friendship and intergroup anxiety. Closeness of friendship only predicted lower intergroup anxiety, however, when the out-group friend was perceived as highly typical. The authors emphasize the importance of considering the nature of out-group attitudes more completely when evaluating the effectiveness of intergroup contact in reducing prejudice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

结构强度储备的评估及结构维修过程的跟踪决策

本文提出了已建成结构在服役过程中构件的强度储备比和结构整体的强度储备比的概念和定义,它们都是随结构使用和维修过程而变化的时间的函数。我们建议以实际的强度储备比作为构件和结构服役安全度的表达方式,给出了构件和结构强度储备比的具体评定方法,并以结构整体的强度储备比作为控制参数决策结构的维修过程,以求得结构全寿命维修的优化控制。本文所提出的方法适用于具有良好的结构重分析程序和精密细致的检测手段的工程。一般重要的结构工程,例如核电站、海上结构、航空航天设备等均具备上述条件。因而本文所提的方法非常实用,可以立即应用于重要的工程项目,具有重大的经济和社会效益。     

关于混凝土钻芯取样法有关标准的讨论

本文对国内不同行业有关混凝土钻总取样方法的标准进行了讨论，供月行在使用和修订相应标准时参考。     

THE TENSILE STRENGTH OF WATER IN DEPRESSION TANK

This paper presents the data of tensile strength of water in depression tank whichwere measured by small venturi during cavitation investigation of a series of real project models.These measurements show that in depression tank water has slight tensile strength in case of highvacuum.But it influences the incipient cavitation number.In tests we also studied the influenceof tensile strength on scale effect of cavitation models.     

Solubility of amaranth seed proteins in sodium sulphate and sodium chloride: the main factor in quantitative extraction for analysis

Nitrogen was extracted more efficiently from amaranth seed with 0.04 M Na₂SO₄ (5% w/v) than with either 0.09 M or 0.17 M NaCl (5% or 10% w/v), despite both solutions having the same ionic strength (μ= 1). Solubility of saline soluble proteins (albumin ± globulin) was very poor in either water or 1M NaCl, but increased in 0.4M NaCl at alkaline pH between 7 and 10. Globulins were very soluble in 0.4M NaCl at a pH 9. Albumin was the main storage protein. Saline soluble proteins formed very weak gels.     

复合材料压缩破坏模式的缺陷敏感性

本文基于弹塑性分叉理论研究单向纤维增强复合材料的压缩破坏模式和压缩强度对缺陷的敏感性问题。对于常见复合材料,所得结论是:无缺陷或者小缺陷情况的破坏模式为倾斜破坏带;大缺陷情况的破坏模式为水平破坏带;形成水平破坏带的压力值小于形成倾斜破坏带的压力。     

Evaluating Liquefaction Strength of Partially Saturated Sand

A method is presented for evaluating the liquefaction strength of partially saturated sand using the compression wave velocity (P-wave velocity), a new indicator of saturation. Based on laboratory test results, an empirical correlation that relates the liquefaction strength with the pore pressure coefficient B is firstly proposed. The strength is defined as the cyclic stress ratio required to cause liquefaction at a specified number of cycles. With the aid of a theoretical relation between B and the P-wave velocity, an explicit correlation of more interest is then established between the liquefaction strength of sand and its P-wave velocity. A comparison of the predictions using this explicit correlation with laboratory measurements shows a satisfactory agreement. The significance of this method lies in that it makes it possible to evaluate the liquefaction strength of sand as affected by saturation through the measurement of P-wave velocity, which can be made not only in the laboratory but particularly in the field.     

薄管板换热器的设计及薄管板计算的探讨

结合化肥厂丁辛醇装置薄管板换热器的设计 ,着重分析薄管板的特点 ,应用合理的计算方法对薄管板进行强度校核 ,验证这一新型换热器的安全性和经济实用性