摘要：使用非线性有限元程序系统ADINA ,对南水北调中线穿黄连续刚构方案的预应力U型薄壳渡槽进行了结构分析 .给出了静力分析结果和动力特性分析结果 .结果表明 ,与简支方案相比 ,连续刚构方案结构减小了变形、应力和钢筋用量 ,最大压应力和最大拉应力均满足规范中的强度设计要求 ,最大位移也满足刚度要求 .

摘要：为提高软件缺陷自动修复技术的修复效果,针对面向对象程序中出现概率较大的方法调用缺陷,提出一种基于深度学习和遗传算法的方法调用缺陷自动修复方法。基于深度学习构造方法调用缺陷修复模型,使用修复模型生成候选补丁并验证;若补丁无效,则基于这些候选补丁,使用改进的基于遗传算法的缺陷修复方法生成候选补丁。实验结果表明,在Defects4 J数据集上,所提方法与DEAR、TBar、SequenceR和jGenProg自动化缺陷修复工具相比,缺陷修复率和补丁正确率都有提高。

摘要：针对动车用压接端子过载承受能力的研究,设计了13种不同线缆线径和8种压线钳的合理压接匹配分组,压接并对所得压接端子试样均进行短时耐受流试验,测量了各个试样在试验前后的压接电阻值,计算出电阻值变化率。采用了Origin7.5对短时耐受流试验进行数据处理,并对比分析,研究了线缆线径与压线钳的匹配关系和压接工艺这两个方面对压接端子性能的影响。研究结果表明:线缆线径与压线钳的合理匹配关系会导致压接端子过载承受能力的不同,为了保证高品质电气性能的压接端子,应针对不同线径的线缆采用不同型号的压线钳进行压接,并严格把控压接质量。

摘要：介绍了EQ-201型炔化催化剂的制备及使用性能,并与进口工业样进行了对比性试验,结果表明,EQ-201型炔化催化剂具有明显的工业应用价值。

摘要：连续循环短节可在停钻时保持钻井液连续循环，实现连续循环钻井，有效解决井底沉渣、井底压力波动等问题，尤其适合海域油气水平井钻井工程。本文设计了一种连续循环短节，介绍了短节结构及工作原理，并对极限工况下的短节本体强度进行了受力分析和结构优化设计，优选了本体安全系数大于1.2的旁通阀侧开孔；对旁通阀进行了有限元受力分析，从应力分布和密封比压两方面综合分析，得到了密封副半锥角和阀芯板厚度变化对旁通阀受力和密封效果的影响规律，优选出了密封副半锥角α=30°和阀芯板厚度δ=8 mm，并对优选结构参数的连续循环短节进行了旁通阀密封测试和本体强度测试，证明短节强度和密封性能均满足极限内压力35 MPa和极限拉力3503 kN的实际使用需求。

摘要：A structure-based microstrip passband filter with the center frequency of 2.6 GHz was put forward by using double-mode resonator based on defected ground structure （DGS） technology. A double-mode coupling resonator combined with DGS structure was used to achieve the resonance frequency and the filter size. CST microwave studio was used to optimize the attenuation performance to get the filter parameters. A structure-based passband filter was fabricated. Simulation is consistent with the measurement. Performance shows that the proposed filter could be suitable for the time division-long term devolution （TD-LTE） microwave systems at 2.6 GHz.

摘要：为了实现单次扫描条纹相机扫描控制模块中斜坡信号的高电压阈值、高线性斜坡、电路简单且易调试的目标,提出了利用开关放电产生大电流高压脉冲和恒流充电斜坡线性好的优点,设计出一款单次扫描线性高压斜坡信号产生电路,该电路可通过调节电阻的大小,实现线性斜坡信号斜率和线性率的调节和优化。实验表明,该电路所产生的线性高压斜坡信号可提供幅值高达1700 V的电压,产生的斜坡非线性精度小于3%,扫描时间可实现200 ns至50μs可调。与传统高压斜坡信号电路相比,电路结构简单,调试方便,斜坡时间可实现纳秒到微秒的无级调整,这可有效提高条纹相机扫描时间精度,有效减小电路串扰等问题。

摘要：电子枪是行波管中提供电子注的核心部件,其质量的好坏直接影响整管的性能、寿命和可靠性。实验和数值模拟相结合的方法对电子枪阴极热屏组件进行热学和结构可靠性研究。首先通过ANSYS软件对电子枪阴极支撑筒结构参数进行仿真计算,研究了各参数对结构热效率和可靠性的影响,并对阴极支撑筒结构进行了优化设计及实验验证。实验结果表明,优化后的电子枪结构加热功率由3.32 W降低至2.83 W,热效率提高了14.8%,同时整管通过了力学鉴定实验,证明了电子枪阴极支撑结构的可靠性。优化后的电子枪组件在热效率和可靠性方面均有了一定的提升,为阴极支撑筒结构的优化设计提供了一定的参考价值。

摘要：With the rapid growth in fingerprint databases, it has become necessary to develop excellent fingerprint indexing to achieve efficiency and accuracy. Fingerprint indexing has been widely studied with real-valued features,but few studies focus on binary feature representation, which is more suitable to identify fingerprints efficiently in large-scale fingerprint databases. In this study, we propose a deep compact binary minutia cylinder code（DCBMCC）as an effective and discriminative feature representation for fingerprint indexing. Specifically, the minutia cylinder code（MCC）, as the state-of-the-art fingerprint representation, is analyzed and its shortcomings are ***, we propose a novel fingerprint indexing method based on deep neural networks to learn *** novel network restricts the penultimate layer to directly output binary codes. Moreover, we incorporate independence, balance, quantization-loss-minimum, and similarity-preservation properties in this learning ***, a multi-index hashing（MIH） based fingerprint indexing scheme further speeds up the exact search in the Hamming space by building multiple hash tables on binary code substrings. Furthermore, numerous experiments on public databases show that the proposed approach is an outstanding fingerprint indexing method since it has an extremely small error rate with a very low penetration rate.

摘要：This review mainly summarizes the latest developments in the internal flow field and external characteristics of centrifugal *** particular,the latest findings of centrifugal pumps focused on turbulence and cavitation models,flow visualization methods,and fault detection based on noise and *** external characteristics,cavitation,and vibration of the centrifugal pump were extensively *** addition,advanced multi-objective optimization methods for improving impeller’s efficiency and reducing net positive suction head(NPSH)were *** some progress was made in this field,there remain many unsolved problems,such as monitoring and modeling of cavitation,rotational stall phenomenon,and discrepancies between simulation and *** the future,researchers are encouraged to employ multi-dimensional flow visualization technologies and high-performance computing facilities to advance existing understandings on these issues and create new research directions.