非鲁棒路径时滞故障测试生成算法

针对数字电路中非鲁棒路径时滞故障测试时间长、故障覆盖率较低的问题,提出了人工蜂群优化的测试生成算法。该算法首先应用电路转换法则把数字电路转换成为其等效电路,然后用Hopfield神经网络构建等效电路单固定故障的约束电路,并得到能量函数;再应用人工蜂群优化算法计算能量函数的最小值以得到等效电路单固定故障的测试矢量,最后根据对应关系得到原电路非鲁棒路径时滞故障的测试矢量对。在ISCAS’85国际标准电路上的实验结果表明:该算法故障覆盖率能够达到98%,并且平均测试生成时间小于0.8 s。     

基于人工蜂群算法的数字电路多故障测试生成算法

针对数字电路多固定故障测试生成故障覆盖率低和平均测试生成时间长的问题,提出了人工蜂群和神经网络优化的数字电路多固定故障测试生成算法。该算法首先通过等效的方法得到多固定故障的单固定故障模型,再使用Hopfield二值神经网络的方法得到单固定故障的约束电路模型,最后使用人工蜂群优化方法求解故障约束电路接口电路的能量函数的零值点获得原电路的多固定故障的测试生成矢量。实验结果(在ISCAS’85国际标准测试电路上)表明该算法的故障覆盖率可达98.5%以上,平均测试生成时间小于0.25μs。     

一种有效的组合电路测试生成算法

为了改善组合电路测试生成效率,提出了一种有效的基于三值神经网络的组合电路测试生成算法。该算法不需要传播和回溯,而是使用三值神经网络把组合电路表示为双向神经元网络,并构建网络的能量函数,最后使用遗传算法求出全局最小值点作为电路的测试矢量,所以组合电路的测试生成问题转换为优化问题。在标准电路上的测试实验结果表明该算法具有较高的故障覆盖率和较短的测试生成时间。     

基于三值神经网络和混沌搜索的数字电路串扰时滞故障测试生成算法（英文）

提出了一种有效的串扰时滞故障测试生成算法,该算法使用了三值神经网络理论和混沌搜索方法。首先在电路的受害点处把电路分成两个部分,对第一部分,可以得到时滞时间表达式;对第二部分,使用混沌搜索和三值神经网络网络的方法把故障传播到输出端。最后,能够把故障传播到输出端且使时滞时间表达式取最大值的输入矢量就是串扰时滞故障的最优测试矢量。实验结果表明该算法能够容易地得到故障输入测试矢量,平均测试生成时间小于0. 25μs,故障覆盖率能够达到98. 2%。     

基于三值神经网络和混沌搜索的数字电路串扰时滞故障测试生成算法

提出了一种有效的串扰时滞故障测试生成算法,该算法使用了三值神经网络理论和混沌搜索方法。首先在电路的受害点处把电路分成两个部分,对第一部分,可以得到时滞时间表达式;对第二部分,使用混沌搜索和三值神经网络网络的方法把故障传播到输出端。最后,能够把故障传播到输出端且使时滞时间表达式取最大值的输入矢量就是串扰时滞故障的最优测试矢量。实验结果表明该算法能够容易地得到故障输入测试矢量,平均测试生成时间小于0. 25μs,故障覆盖率能够达到98. 2%。     

数字电路阈值故障测试生成算法

提出一种有效的数字电路故障阈值故障测试生成算法。首先构造出数字电路的阈值测试模型,通过这个模型可以区分出可接受故障和不可接受故障,然后使用成熟的固定故障测试生成算法得到不可接受故障的测试生成矢量。在ISCAS’85和ISCAS’89电路上的实验结果表明:该算法的故障覆盖率能达到96%,故障测试生成时间少于0. 019 s。     

基于人工蜂群算法的机器人路径规划

为求解机器人路径规划问题,引入人工蜂群算法,并将路径空间以网格划分,通过固定起始节点和设定最大允许路径节点数等方法,解决了人工蜂群算法应用于路径规划的两个难题--路径节点不固定和邻域构造困难,实现了将ABC算法应用于路径规划问题.通过典型的实例仿真对算法性能进行测试,结果表明:该算法有效克服了停滞行为的过早出现,而且能够加快收敛速度,得到全局最优解或近似解,是解决机器人路径规划问题的一种有效算法.     

改进ABC算法的串联机械臂多目标优化

针对串联机械臂工作时间最优、能耗最优、脉动最优的轨迹优化问题,提出一种基于改进人工蜂群算法的多目标轨迹优化方法。文中采用5次NURBS曲线插值法建立工作轨迹数学模型,构造高阶连续关节运行轨迹并对其进行合理规划。以串联机械臂运行时间、能量消耗和脉动冲击为目标建立目标函数,通过改进人工蜂群算法进行优化设计并获得Pareto最优解集,运用归一化权重目标函数获取期望解。选择PUMA560串联机械臂进行仿真分析,结果表明:5次NURBS曲线轨迹规划方法有效构造平滑轨迹,改进人工蜂群算法能够实现满足约束条件的多目标优化,验证了算法的有效性,为后续研究奠定基础。     

基于人工蜂群算法的双机器人路径规划分析

针对手动液压搬运车车架主焊工序双机器人同步焊接路径规划问题,文中引入虚拟点将多旅行商问题转化为单旅行商问题,选用换位表达编码方式对车架焊缝编码,然后采用基于状态转移策略的人工蜂群算法建立双机器人同步焊接数学模型,仿真求解全局最优焊接路径的较好近似解,并与改进的自适应遗传算法以及人工鱼群算法做了仿真对比试验.结果表明,人工蜂群算法不会过早停滞,具有较快收敛速度,较其它两种算法更能缩短焊接工时,基于人工蜂群算法的双机器人路径规划方法能有效解决搬运车车架主焊工序双机器人同步焊接问题.     

基于改进蜂群算法的焊接机器人路径规划方法研究

针对焊接机器人的运动特点及焊接工作过程中焊枪的避障问题,提出基于改进人工蜂群算法的机器人避障焊接路径规划策略。首先针对传统人工蜂群算法存在的问题,将Lévy(莱维)分布引入到人工蜂群算法侦查蜂寻找新蜜源的过程中,代替其原有0～1之间的随机分布过程,形成了基于Lévy飞行的改进型人工蜂群算法,然后将其应用到焊接机器人的路径规划问题中,并进行了仿真实验。结果表明:改进后的方法能够得到最优的焊接避障路径,且寻优速度快、过程稳定。该方法可用于解决焊接机器人避障路径规划问题。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.