提高高铬白口铸铁磨球冲击抗力的技术关键

当高铬白口铸铁含铬量为18%～28%,Cr/C值是8￣9,铸铁的显微组织是回火马氏体 少量残余奥氏体(<5%) M7C3碳化物,则磨球具有高的冲击韧性和断裂韧性K1C,具有高的冲击抗力,表现出低的冲击剥落量。     

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.     

基于漏磁原理的钢丝绳探伤仪影响因素研究

介绍了钢丝绳探伤仪漏磁检测原理,并使用有限元分析方法分析了传感器零件的材料、钢丝绳的提离距离及断丝根数等对基于漏磁原理的钢丝绳探伤仪检测结果的影响。分析结果表明,提离距离、断丝根数等因素对探伤仪检测结果影响较大,断丝角度、深度等因素影响较小。     

高压切割喷嘴冲击磨损的数值分析

以复用矿井含煤颗粒的水对高压切割喷嘴的磨损物理问题为研究对象,采用计算流体力学理论进行数值计算,分析讨论了质量浓度为10、15、20、25、30、40 mg/L条件下速度、剪应力、磨损的分布以及变化关系。计算、分析结果表明:磨损主要发生在出口部位和锥体的后半部份,入口部份和锥体前半部份磨损较小;入口部位、锥体部位磨损量、剪应力随质量浓度增加变化较小;出口部位磨损量在质量浓度为10～20 mg/L减小较快,超过20 mg/L后变化不大;出口部位流体速度、磨损量、剪应力与质量浓度间存在对应关系。煤粒入口速度与混合物速度相同、锥体部位煤粒流体速度低于锥体部位混合物速度(平均值)约79.4%;煤粒出口部位速度随质量浓度的增大而呈现先增加后减小的趋势,速度最大值发生在浓度20 mg/L。     

Safety assessment of the NET Predesign

Work carried out by European Associations on Safety and Environment inside the EC Fusion Technology Programme and by NET has been concentrated on safety-related guidance and on safety assessment of the NET Predesign. Emphasis has been put on analysis of accident sequences of regulatory concern up to worst case accidents, including quantification of consequences to components, systems, and plant, and of doses to the public. Probabilistic safety studies for the most important systems and broadly for the entire plant have been performed to supplement the calculated accidental doses by expectation values for their occurrence rate, and to check the relevance of the reference accident sequences selected initially by judgment. Waste masses per year of operation and for decommissioning have been quantified. For two countries and according to the practices and regulations of these countries, volumes of radioactive waste packaged for final disposal have been determined.Presented at the IAEA Technical Committee Meeting on Developments in Fusion Safety, Toronto, June 7–11, 1993.     

Dynamic response of Kevlar®29/epoxy laminates under projectile impact-experimental investigation

This authors of this article investigated the dynamic response of woven Kevlar®29/epoxy laminates subjected to the impact loading. The cylindrical aluminum foam projectile and steel projectile were used to exert the impulse on the laminates. Deformation/failure modes, deflections, strain histories, and failure mechanisms were obtained and discussed. The results showed that with the high toughness of Kevlar fiber, the deformation modes of the laminates exhibited some characteristics similar to the metal panel, such as large global deformation. The failure mechanisms like matrix failure, fiber splitting, and fibrillation were observed. These micron failures led to the macroscopic delamination and fracture of the laminates.     

基于集成学习的规范化LDA人脸识别

针对人脸识别问题中经常面临的“小样本”问题,在规范化的LDA算法的基础上加以改进,并结合集成学习的方法,利用Adaboost算法,在每一次的迭代过程中引进一个加权函数对难以分离的样本增加权重。增加分类器之间的差异度,从而提高样本在新的特征空间中的可分离性,将识别率提高至98.5%。通过ORL数据库的大量实验表明,该算法比传统算法有更好的性能。     

基于稀疏PCA的多阶次分数阶傅里叶变换域特征人脸识别

文章提出基于稀疏PCA的多阶次分数阶傅里叶变换(fractional Fourier features,Frft)特征的人脸识别(Multiple Order discrete fractional Fourier Features ,MOFF). 鉴于分数阶傅里叶变换对光照、表情的鲁棒性, 并已在图像处理领域得到应用,首先,Frft幅度随阶次的变换呈现压缩性,而SPCA提取其主要信息将且分为主要信息域和次要信息域,融合二者的互补信息组成混合幅度特征,然后融合混合幅度特征、实部特征和虚部特征,最后融合不同阶次下Frft域特征。此外该文提出基于贪婪算法的分数阶阶次选择算法和基于Fisherfaces的权重方法。ORL 和AR人脸数据库上的仿真证明了本算法的有效性。     

Dynamic Response Calculation of Spatial Elastic Multibody Systems with High-Frequency Excitation

The objective of this paper is to establish a computationalscheme for dynamic response calculations of a three-dimensionalmultibody mechanical system with impulsive forces, which give rise tohigh-frequency excitations. The finite-element method is employed torepresent the local deformations of three-dimensional beam-like elasticcomponents by either a finite set of nodal coordinates or a truncatedset of modal coordinates. A reduced-order model is obtained by invokinga modal transformation. Both planar and complex modal reduction schemesare established. The developed formulation is implemented into amultibody simulation program that assembles the equations of motion andproceeds with its solution. The computational scheme permits a change inthe basis of the modal space in order to regulate the admittance ofhigher frequencies and to accommodate any change in the kinematicconfiguration. Numerical examples are presented to demonstrate theapplicability of the developed computational scheme.     

Online face recognition system based on multi-view algorithm and Kernel PCA

An online face recognition system is presented in the paper. To online face recognition system, we should consider the recognition rate, the image compression and image size. In the paper we researched the innovation technologies for face recognition system, including Kernel Principal Component Analysis （Kernel PCA）, Delta low-pass wavelet filter, and face recognition algorithm using multiple images. Kernel PCA is derived to classify the characteristics of training images in the database. Delta low-pass wavelet filter is used to reduce the image size. A face recognition algorithm using multiple images is presented to improve the recognition rate. Simulation experiment shows that in the case of packet loss recognition rate is improved highly.