Research and Application of Dynamic Equation for Full Frontal Impact

Full frontal impact theory needs researching and exploring to satisfy the primary safety design of occupant restraint system,avoiding the increasingly "engineering"trend in order to develop and design safety vehicle. After occupant restraint system is simulated by using linear elastic stiffness k,the occupant-vehicle frontal rigid barrier impact model is established. Dynamic equation of dummy chest coupling vehicle is built for full frontal impact based on ordinary vehicle deceleration by Hooke law,and the equation is solved by comparing coefficient and satisfying boundary qualifications. While relative vehicle characteristic parameters are kept unchanging,the actual vehicle deceleration is fitted to the simplified equivalent square wave( ESW),tipped equivalent square wave( TESW) and equivalent dual trapezoids wave( EDTW). Phase angle  and amplitude A of dynamic equations based on ESW,TESW and EDTW are calculated and deduced. The results show that: the dynamic equation of dummy chest coupling vehicle can be well utilized to instruct the primary safety design of full frontal impact for objective vehicle to satisfy chest deceleration demands and the equation based on TESW is best for this design.     

对变压器真实油温的智能化监测

本文中作者通过FLUENT温度场解析和变压器实物温升试验,找出了变压器油温最热的真实位置,从而提出智能化监测的解决方案,为真实反映油温升提供可靠的依据.     

Oxidation Performance of Fe-Al/WC Composite Coatings Produced by High Velocity Arc Sprayed at 650 ℃

Fe-Al intermetallics with remarkable high-temperatureintensity and excellent erosion,high-temperatureoxidation and sulfuration resistance are potential lowcost high-temperature structural material.ProducingFe-Al/WC composite coating by high velocity arcspraying(HVAS)on structural materials would notonly obviate the problems faced in fabrication of thesealloys into useful shapes,but also allow the effectiveuse of their outstanding high-temperature performance,which might thus promisingly mak…     

The influence of sulphate-reducing bacteria biofilm on the corrosion of stainless steel AISI 316

This work investigates microbially-influenced corrosion (MIC) of stainless steel AISI 316 by two sulphate-reducing bacteria, Desulfovibrio desulfuricans and a local marine isolate. The biofilm and pit morphology that developed with time were analyzed using atomic force microscopy (AFM). Electrochemical impedance spectroscopy (EIS) results were interpreted with an equivalent circuit to model the physicoelectric characteristics of the electrode/biofilm/solution interface. D. desulfuricans formed one biofilm layer on the metal surface, while the marine isolate formed two layers: a biofilm layer and a ferrous sulfide deposit layer. AFM images corroborated results from the EIS modeling which showed biofilm attachment and subsequent detachment over time.     

管理史对MBA的边际效用

近年来 ,我国MBA的社会评价不高 ,其根本原因是MBA毕业生不能满足市场要求。本文通过分析管理史的功能 ,得出学习管理史对MBA的边际效用大 ,MBA培养方案中有必要增设管理史类的课程。     

New method for determination of the pose of the grinding wheel for thinning drill points

Traditionally, twist drills are reconditioned by thinning the web so the correct chisel edge length is restored. Recently, thinning has been included in the original design of drills so as to reduce torque and tool force. Because the International Standards Organization (ISO) has a system which can comprehensively model conventional twist drills but cannot model thinning specifications, this paper presents a system for precise mathematical modeling and CNC control of a 6-axis grinding workstation for drill thinning. The presented method determines the position and orientation of the grinding wheel based on the evaluated rake and clearance angles of ISO standards for 2-flute twist drills. The mathematical model and background are discussed. For verification and demonstration, two experimental drills are produced to the identical ISO standard except that one is thinned. The modeling herein is of value to industry and research if incorporated into computer software for drill design and manufacture. It is suitable for linear notch-type cutting with controlled variable rake angle along the secondary cutting edge for purposes of thinning, notching, dubbing and advanced drill research.     

机械镀锌过程中先导金属的研究

通过多次试验观察，借助于扫描电子显微镜，结合物理化学、电化学的基础理论知识，对机械镀锌过程中先导金属进行了研究。分析了先导金属在镀层中的分布以及先导金属对机械镀锌形层过程的影响。结果表明机械镀锌过程中的确有先导金属存在，在机械镀锌过程的不同阶段，有着不同的金属起着先导金属的作用。先导金属可以促进机械镀锌镀层的结合强度。     

基于Word文档的数据隐藏方法

在分析当前数据隐藏与恢复相关技术研究基础上,参照微软官方最新公布的复合文档存储规范,从利用载体Word文档现有空间中未真正使用部分和适度扩展新空间两条思路出发,设计一种利用Word文档作载体隐藏秘密信息的解决方案,包括在文字、各种嵌入式对象及其相应控制结构数据中隐藏信息。实践表明,隐藏数据后的载体文档可以被正常拷贝和使用电子邮件传送,根据需要隐藏的信息随机选择使用该方案,被隐藏信息更不容易被侦测出来,被二次编辑后被隐藏信息一般不会被破坏,鲁棒性不错,具有一定的实用价值。     

如何在C语言教学中帮助学生树立信心

该文对C语言教学中两种不同的教学思路做了举例、分析和比较,偏重算法的教学有助于培养学生研究算法编制程序的能力,但对初学者培养兴趣、树立信心方面没有益处,在这方面偏重语法的教学更有效率,建议在教学实践中注重两者的结合。