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桥梁支架预压形变有限元模拟与预拱度优化设置
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作者 钱明明 龙四春 +2 位作者 刘茂琪 赖咸根 周健 《矿业工程研究》 2024年第3期51-57,共7页
为研究支架预压形变规律,优化传统预拱度设置曲线,以长株潭西环线高架桥区间满堂支架结构预压试验为工程背景,结合设计预压方案和现场施工情况,选取31-32桥跨支架结构实测数据和模拟数据进行对比分析,并用多项式拟合的方法对预拱度曲线... 为研究支架预压形变规律,优化传统预拱度设置曲线,以长株潭西环线高架桥区间满堂支架结构预压试验为工程背景,结合设计预压方案和现场施工情况,选取31-32桥跨支架结构实测数据和模拟数据进行对比分析,并用多项式拟合的方法对预拱度曲线进行优化设置.结果表明:高架桥预压预拱度设置曲线并非一条平滑的二次函数曲线,根据四次多项式拟合得到的预拱度曲线更符合现场实际工况.并用7-8桥跨支架结构的实测数据和拟合所得的预拱度曲线进行对比分析,证实采用多项式拟合法优化施工预拱度曲线具有可行性,研究结果可为类似桥梁预压施工提供参考. 展开更多
关键词 满堂支架 有限元模拟 预压形变 预拱度优化
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基于数值分析的浅埋煤层采动滑坡稳定性研究 被引量:4
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作者 刘茂琪 刘萍 +2 位作者 朱恒忠 王沉 王春华 《煤矿安全》 CAS 北大核心 2021年第2期225-230,共6页
以贵州某矿上部山体崩滑地质灾害为例,采用离散元及有限元数值分析方法,建立崩滑体二维、三维数值计算模型,计算出煤矿上部坡体在地下采掘作用下其稳定系数变化过程,并从位移、应力和应变方面对山体失稳过程分析崩滑体的形成机制。研究... 以贵州某矿上部山体崩滑地质灾害为例,采用离散元及有限元数值分析方法,建立崩滑体二维、三维数值计算模型,计算出煤矿上部坡体在地下采掘作用下其稳定系数变化过程,并从位移、应力和应变方面对山体失稳过程分析崩滑体的形成机制。研究结果表明:天然工况下煤矿地下采掘活动对上部山体稳定性造成影响,当地下采煤活动临近山体时,采掘活动对山体稳定性影响较小,但是,当采掘活动在山体下部进行时,其对山体稳定性影响逐渐增大,这说明了地下采掘活动是导致贵州某矿上部山体发生崩滑灾害的发生主要因素之一。 展开更多
关键词 山体稳定性 采动滑坡 地下采掘 数值分析 稳定性系数
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Levels of Metabolic Enzymes and Nitrogenous Compounds in the Swimming Crab Portunus trituberculatus Exposed to Elevated Ambient Ammonia-N 被引量:5
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作者 PAN Luqing SI Lingjun +2 位作者 liu Shengnan liu maoqi WANG Guohui 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第4期957-966,共10页
This study investigated the effects of ammonia-N(control and 1 and 5 mg L^(-1)) on the changes of metabolic enzymes activities and nitrogenous compounds levels in the gills, hepatopancreas, muscles, and hemolymph of t... This study investigated the effects of ammonia-N(control and 1 and 5 mg L^(-1)) on the changes of metabolic enzymes activities and nitrogenous compounds levels in the gills, hepatopancreas, muscles, and hemolymph of the swimming crab Portunus trituberculatus. Results showed that the levels of hemolymph ammonia increased significantly at 6 h and then decreased to control level at 12 h. The activities of key enzymes involved in biosynthesis pathways of glutamine(Gln) and urea, such as glutamate dehydrogenase(GDH), glutamine synthetase(GS), and arginase(ARG), increased remarkably in different tissues of P. trituberculatus. Gln level was the highest in muscles, while urea content was the largest in hepatopancreas. The m RNA expression level of xanthine dehydrogenase(XDH) was downregulated sharply in gills but upregulated in the hepatopancreas and muscles. A small amount of uric acid was detected in the hemolymph. This result suggests that Gln in muscles may be used as an intermediary nitrogen repository, while urea may be primarily synthesized in the hepatopancreas and then transferred to other tissues via the hemolymph. Uric acid could be synthesized by the anabolism of purine nucleotides, in additon to the inhibitory activities of gills. In addition, the levels of Gln, urea and uric acid exhibited dose-and time-dependent effects with ammonia content. Therefore, P. trituberculatus could possibly convert ammonia into Gln, urea, or uric acid to detoxify ammonia during high ambient ammonia-N stress. 展开更多
关键词 AMMONIA Portunus TRITUBERCULATUS GLUTAMINE UREA uric acid
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Design of LCoS-Based Twin 1×40 Wavelength Selective Switch
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作者 WANG Han liu maoqi +2 位作者 FENG Zhenhua liu Minghuan MAO Baiwei 《ZTE Communications》 2024年第4期18-28,共11页
Wavelength selective switch(WSS)is the crucial component in the reconfigurable optical add/drop multiplexer(ROADM),which plays a pivotal role in the next-generation all-optical networks.We present a compact architectu... Wavelength selective switch(WSS)is the crucial component in the reconfigurable optical add/drop multiplexer(ROADM),which plays a pivotal role in the next-generation all-optical networks.We present a compact architecture of twin 1×40 liquid crystal on silicon(LCoS)-based WSS,which can be regarded as a 4f system in the wavelength direction and a 2f system in the switching direction.It is designed with theoretical analysis and simulation investigation.Polarization multiplexing is employed for two sources of twin WSS by polarization con-version before the common optical path.The WSS system attains a coupling efficacy exceeding 96%for 90%of the ports through simulation optimization.The 3 dB bandwidth can be achieved by more than 44 GHz at a 50 GHz grid for all 120 channels at all deflection ports.This work establishes a solid foundation for developing high-performance WSS with larger port counts. 展开更多
关键词 wavelength selective switch(WSS) liquid crystal on silicon(LCoS) optical structure design insertion loss
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