石油天然气长输管线用钢新进展

本文介绍了１９９０年以来国外在石油天然气长输管线用钢方面的最新成果，以获得较低的强度和韧性匹配为目的经轧后加速冷却工艺后的钢的强度的预测和控制；具有优良抗氢致裂纹的含硼、微碳、低硫、Ｎｂ－Ｔｉ微合金化、Ｘ６５－Ｘ８０级管线钢的开发，满足于特殊性能要求的ＴｉＯ处理技术及Ｘ８０级ＴｉＯ细化晶粒钢、低硬度和低屈强比钢，以及复合板加工耐腐蚀钢管的生产。     

割缝防砂筛管抗挤强度有限元计算模型

针对割缝防砂筛管周围或缝内部堵塞，造成井眼压力增加，可能会导致筛管被挤毁的问题，采用有限元方法，通过大型有限元程序，建立了其抗挤强度的有限元计算模型。根据弹塑性理论，对割缝防砂筛管进行分析，得出其抗挤强度。结果与国外的实验数据进行对比，数值模拟结果比实验值略大，但两者相差较小，证明了该模型的正确性。为其他尺寸割缝筛管的抗挤强度设计提供了一种数值计算方法。     

Glass-ceramics of barium strontium titanate for high energy density capacitors

Barium strontium titanate glass-ceramics were successfully produced with one major crystalline phase when Al₂O₃ was added to the melt. A dielectric constant of 1000 and a breakdown strength of 800 kV/cm was achieved; however the energy density was only measured to be 0.3–0.9 J/cm³. These energy density values were lower than anticipated due to the presence of dendrites and pores in the microstructure. Using BaF₂ as a refining agent improved the microstructure and doubled the energy density for BST 80/20 samples. However, no refining agent reduced the increasing amount of hysteresis that developed with increasing applied electric field. This phenomenon is believed to be due to interfacial polarization.     

双相位共轭镜的工作条件参数分析

本文讨论了纯扩散机制的光折变晶体用作单作用区的双相位共轭镜（ＤＰＣＭ）时的阈值耦合强度和允许的输入光强比范围，并与双作用区的情况进行比较后，给出了在输入光强比远离１的条件下，双相位共轭镜的正常工作的条件参数。     

砼回弹法测强统计分析

简述了砼回弹法测强与抗压强度对比试验的方法，得出了影响砼回弹测强的种种因素，通过统计分析给出了砼回弹测强的实用计算公式，从而就可在结构物上直接进行回弹测强，达到及时，方便，准确地了解结构物的强度．     

三峡工程左厂房坝导墙抗震计算分析

 用反应谱理论对三峡左厂房坝导墙3种典型设计断面型式进行了抗震计算分析比较，得出了其自振特性及地震动位移、动应力响应。对选定的设计断面型式Ⅲ进行了抗拉应力强度安全性评价。     

Multi-channel SAR imaging based on distributed compressive sensing

The rapid development of compressive sensing(CS)shows that it is possible to recover a sparse signal from very limited measurements.Synthetic aperture radar(SAR)imaging based on CS can reconstruct the target scene with a reduced number of collected samples by solving an optimization problem.For multi-channel SAR imaging based on CS,each channel requires sufficient samples for separate imaging and the total number of samples could still be large.We propose an imaging algorithm based on distributed compressive sensing(DCS)that reconstructs scenes jointly under multiple channels.Multi-channel SAR imaging based on DCS not only exploits the sparsity of the target scene,but also exploits the correlation among channels.It requires significantly fewer samples than multi-channel SAR imaging based on CS.If multiple channels offer different sampling rates,DCS joint processing can reconstruct target scenes with a much more flexible allocation of the number of measurements offered by each channel than that used in separate CS processing.     

100 t伸缩臂履带式起重机臂架结构设计和优化分析

为确保100 t伸缩臂履带式起重机臂架结构设计的合理性,采用壳单元建立该起重机的有限元模型,用ANSYS计算臂架结构应力和应变,得到臂架的应力和应变分布,验证臂架的强度和稳定性.在起重机性能满足要求的情况下,以减轻结构自重为优化目标,以截面尺寸为优化设计变量,用ANSYS对臂架进行优化设计.优化设计后的臂架满足设计规范,臂架截面尺寸缩小、自重降低,整机性能得到提高.