15XYG45—(3)蓄电池组节银新法

15XYG45—(3)碱性蓄电池组通过采用处理铜丝编网代替银丝编网作负极板骨架,减少正极物质量和聚乙烯接技膜代替一层再生纤维素膜,可使其性能接近或保持原有的技术水平,且电池银材消耗减少,成本降低。     

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分支井技术可以从一个主井眼中钻成多个相互独立的、可以再次进入的、具有压力封隔效果的分支井，并能进行完井作业。新浅90分支井是由西南石油局设计并施工的中国国内第一口天然气分支并，并在国内首次进行加砂压裂并获圆满成功，也是我国第一口达到TAML五级标准的分支井。该井在吸收国内外成功经验的基础上，研究出了一套适合于气井作业的分支井钻井完井配套工艺技术。结合川西地区气井多产层、高压力梯度、河道砂体岩性变化大等地质特点，该井组主井眼和分支井眼均采用套管固井、射孔完成，通过双油管和双封隔器的完井管柱实现了主井眼和分支井眼的层间压力分隔和分井压裂、分井采气。     

Multi-objective crashworthiness optimization of tapered thin-walled tubes with axisymmetric indentations

In this paper, the effects of tapering and introducing axisymmetric indentations on the crash performances of thin-walled tubes are investigated. The crash performances of the tubes are evaluated using two metrics: the crush force efficiency (CFE, the ratio of the average crushing load to the peak load), and the specific energy absorption (SEA, absorbed energy per unit mass). The optimum values of the number of the axisymmetric indentations, the radius of the indentations, the taper angle and the tube thickness are sought for maximum CFE and maximum SEA using surrogate based optimization. In addition, multi-objective optimization of the tubes is performed by maximizing a composite objective function that provides a compromise between CFE and SEA. The CFE and SEA values at the training points of surrogate models (metamodels) are computed using the finite element analysis code LS-DYNA. Polynomial response surfaces, radial basis functions, and Kriging are the different surrogate models used in this study. Surrogate based optimization of the tubes showed that the tubes with indentations have better crush performance than tubes without indentations. It is found that maximum CFE requires large number of indentations with high radius, small thickness, and medium taper angle, while maximum SEA requires small number of indentations with low radius, large thickness and small taper angle. It is also found that the globally most accurate surrogate model does not necessarily lead to the optimum.     

Flexural strength analysis of non-post-tensioned and post-tensioned concrete-filled circular steel tubes

Concrete-filled circular steel tubes (CFT) have recently gained significant attention for their enhanced strength and ductility over the conventional steel and reinforced concrete construction. The concrete compressive strength is significantly increased by the lateral confinement provided by the steel tube and local buckling of the steel tube is restrained by the concrete infill. This paper investigates the further enhancement of these composite actions due to post-tensioning the concrete cores inside circular steel tubes. The flexural behavior of a post-tensioned CFT as well as a non-post-tensioned CFT was studied experimentally and analytically. A numerical algorithm for predicting the moment capacities of circular CFT, with or without the post-tensioning effects, has been validated against the test results by the authors as well as those published in the literature.     

电子电路噪声的岔集谱分析法

本文阐明了目前电路噪声理论的不完善性,提出了电子电路岔集谱分析法,使噪声计算的精度和效率有显著提高。作者编制并调试成功了基于此方法的电子电路噪声性能分析和低噪声设计程序,文末给出了实例结果。与实验结果的比较,说明了本文提出方法的正确性。     

管式正极板管窥

本文概述了管式正极板的构造和演变,分析了它的利和弊,介绍了其制作要点和蹾粉注意事项。     

(2n,r,t)_GFNSP结构一类不可能差分对的构造方法

构造不可能差分对是进行不可能差分分析的前提。该文研究了(2n,r,t)_GFNSP结构不可能差分对的构造问题,给出了该结构的一类(4n+1)轮不可能差分对的结构形式以及计算复杂度为O(n2r10)的构造算法,针对Shirai等提出的(2n,r,t)_GFNSP结构的DSM设计策略,本文给出了相应的(4n+1)轮不可能差分对的构造方法。     

浮点数比较分支的混淆方法研究

针对当前分支混淆方法仅对整数比较分支有效的缺陷,该文分析浮点数二进制表示与大小比较的关系,证明了浮点数二进制区间的前缀集合与浮点数区间内数据之间具有前缀匹配关系。使用哈希函数对前缀集合进行保护,利用哈希函数的单向性实现对抗符号执行,通过哈希值比对替换浮点数比较,提出一种基于前缀哈希值比较的分支条件混淆技术,实现了一种在符号执行对抗和混淆还原对抗上具有较强对抗性的混淆方法。最后,通过实验证和分析,证实了该文提出的混淆方法有消耗小、能够有效对抗符号执行和混淆还原的优点,具备较好的实用性。

     

蒸汽发生器隔板和传热管束的水力学载荷分析

蒸汽发生器（ＳＧ）隔板和传热管束的水力学载荷分析ＳＧ隔板和传热管设计的基础,本文介绍了采用法国,ＡＴＨＩＳ和ＦＯＲＣＥＴ程序以及大亚湾核电站输入数据,对秦山二期ＳＧ在ＬＯＣＡ事故时隔板所受的最大压力和传热管束所受的最大水平载荷进行的建模和分析计算,并将计算结果与法马通过的计算结果进行了比较,比较结果表明,两者符合较好,对秦山二期ＳＧ而言其隔板设计的最大压差为８．０ＭＰａ,传热管束设计的最大水平力为     

基于骨架特征的机场主跑道识别

基于骨架对跑道区域进行表示,从骨架图中检测骨架分支基元,计算分支基元的显著性度量并建立分支基元之间的邻接关系。针对机场跑道区域具有的几何特征,采用脊柱基元表示条状区域,将脊柱基元的宽度、长度和方向信息作为脊柱基元的显著性度量,借助先验知识,检测得到主跑道的脊柱基元,识别主跑道。选取一幅某机场遥感图像作为实验分析,验证了算法的可行性。