检索结果-南通市图书馆

平面SV波入射下地上建筑群-地铁隧道群动力相互作用研究

在线全文

学校读者我要写书评

暂无评论

振动与冲击 2024年第4期43卷 27-37页

作者：刘中宪王建旭金立国天津城建大学土木工程学院天津300384 天津市软土特性与工程环境重点实验室天津300384 中国地震局地质研究所强震构造与地震危险性研究室北京100029

该研究采用一种高精度间接边界元方法(indirect boundary element method, IBEM),研究了平面SV波入射下地上建筑群-地铁隧道群的动力相互作用问题。研究表明:“建筑群-隧道群”系统存在显著的动力相互作用,其规律与入射波性质、建筑物... 详细信息

该研究采用一种高精度间接边界元方法(indirect boundary element method, IBEM),研究了平面SV波入射下地上建筑群-地铁隧道群的动力相互作用问题。研究表明:“建筑群-隧道群”系统存在显著的动力相互作用,其规律与入射波性质、建筑物和隧道数量排布等因素密切相关。通过对比不同建筑物数量对隧道动力响应的影响,能够发现:低频波作用下,建筑物对下穿隧道的动力响应有放大作用,而高频波作用下则会削弱隧道的动力响应,最多可以降低37.5%左右。从频域分析中可以看出:隧道对地震波有较强的屏蔽作用,从而降低了其上建筑群的地震响应。建筑群的存在降低了各个单体建筑的动力响应,但在高频波作用时位于建筑群来波一侧的建筑会产生较大的动力响应。该研究成果可为城市建筑群-地铁隧道群的动力相互作用分析以及地上建筑和地铁隧道的抗震设计提供理论依据。

关键词：结构-土-结构相互作用地铁隧道地上建筑群间接边界元法(IBEM) 频谱特性

在线全文

学校读者我要写书评

暂无评论

深切V型峡谷物理驱动人工智能波动模拟

岩土工程学报 2024年第6期46卷 1246-1253页

作者：栾绍凯陈苏丁毅金立国王巨科李小军北京工业大学城市与工程安全减灾教育部重点实验室北京100124 中国地震局地球物理研究所北京100081

高山峡谷区场地地震效应是地震工程领域研究热点。V形峡谷引起的圆柱形SH波散射和衍射波函数的级数解已较为成熟,并为众多河谷区重大工程提供了合理、科学的地震动输入。采用物理驱动深度学习方法结合与解析结果的对比分析,近一步明确了... 详细信息

高山峡谷区场地地震效应是地震工程领域研究热点。V形峡谷引起的圆柱形SH波散射和衍射波函数的级数解已较为成熟,并为众多河谷区重大工程提供了合理、科学的地震动输入。采用物理驱动深度学习方法结合与解析结果的对比分析,近一步明确了V型河谷地形地震反应特性及复杂波场空间分布。此方法主要关注稀疏样本及可诠释性人工智能,结合强形式自动微分和软约束边界条件嵌入,建立深度神经网络实现半无限域地震传播模型。采用时间域分解策略,实现不同给定波场工况下V型河谷高精度预测。通过与解析解对比,评估了所提出的物理驱动人工智能方法的精度和效率。结果表明,物理驱动人工智能方法可应用于地形效应分析,柱面SH波在V型峡谷底端发生显著衰减与振荡,边缘区呈现放大效应。

关键词：物理驱动深度学习河谷地震波动模拟科学人工智能

Mechanical Fault Diagnosis Based on Band-phase-randomized Surrogate Data and Multifractal

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2011年第5期24卷 885-890页

作者： ZHANG Shuqing ZHAO Yuchun ZHANG liguo jin Mei School of Electrical Engineering Yanshan University Qinhuangdao 066004 China

The vibration signals of machinery with various faults often show clear nonlinear ***,fractal dimension analysis as the common useful method for nonlinear signal analysis,is a kind of single fractal form,which only reflects the overall irregularity of signals,but cannot describe its local scaling *** comprehensive revealing of internal properties,a combinatorial method based on band-phase-randomized（BPR） surrogate data and multifractal is *** surrogate data method is effective to eliminate nonlinearity in specified frequency band for a fault signal,which can be utilized to detect nonlinear degree in whole fault signal by nonlinear titration method,and the overall nonlinear distribution of fault signal is displayed in nonlinear characteristic curve that can be used to analyze the fault signal *** multifractal theory as a quantitative analysis method is used to describe geometrical characteristics and local scaling properties,and asymmetry coefficient of multifractal spectrum and multifractal entropy for fault signals are extracted as new criterions to diagnose machinery *** typical faults include rotor misalignment,transversal crack,and static-dynamic rubbing fault are analyzed,and the results indicate that those faults can be distinguished by the proposed method effectively,which provides a qualitative and quantitative analysis way in the field of machinery fault diagnosis.

关键词： fault diagnosis band-phase-randomized surrogate data nonlinear titration multifractal

Combination Mechanism and Enhanced Visible-Light Photocatalytic Activity and Stability of CdS/g-C3N4 Heterojunctions

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第1期33卷 30-38页

作者： Huanyan Xu Licheng Wu liguo jin Kejia Wu School of Materials Science and Engineering Harbin University of Science and Technology Harbin 150040 China

In this study, CdS/g-C3N4 （CSCN） heterojunctions were in situ fabricated with a large amount of CdS nanoparticles anchored on g-C3N4 nanosheets, A wet chemical method was developed for the first time to determine the actual content of CdS in CSCN composites. X-ray diffraction （XRD）, Fourier transform infrared spectra （FFIR）, high-resolution transmission electron microscopy （HRTEM） and UV-vis diffuse reflectance spectra （DRS） were employed to characterize the composition, structure and optical prop- erty of CSCN composites. Based on the is0electric point （liP） analysis of g-C3N4, a conclusion was obtained on the combination mechanism between CdS nanoparticles and g-C3N4 nanosheets. The photocatalytic activity of CSCN composites was much better than those of individual CdS and g-C3N4 for the degrada- tion of azo dye Methyl Orange （MO） by 40 min adsorption in the dark followed by 15 min photocatalysis under visible light irradiation. After 5 cycles, CSCN composites still maintained high reactive activity with the MO degradation efficiency of 93.8%, exhibiting good photocatalytic stability. The Cd2~ concentration dissolved in the supernatant detected by atomic absorption spectroscopy （AAS） of CSCN composites was lower than that of pure CdS, implying that the photocorrosion of CdS could be suppressed via the combination with g-C3N4. Photoluminescence emission spectra （PL） results clearly revealed that the recombination of photogenerated electron-hole pairs in CSCN composites was effectively inhibited due to the formation of heterojunctions. Based on the band alignments of g-C3N4 and CdS, the possible photocatalvtic mechnism was discussed.

关键词： CdS/g-C3N4 Heterojunctions Photocatalytic stability Photocatalytic mechanism

A New Kernel Function Yielding the Best Known Iteration Bounds for Primal-Dual Interior-Point Algorithms

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2009年第12期25卷 2169-2178页

作者： Yan Qin BAI jin liguo Cornelis ROOS Department of Mathematics Shanghai University Shanghai 200436 P. R. China Business School University of Shanghai for Science and Technology Shanghai 200093 P. R. China Faculty of Electrical Engineering Mathematics and Computer Science Delft University of Technology P.O. Box 5031 2600 GA Delft The Netherlands

Kernel functions play an important role in defining new search directions for primal-dual interior-point algorithm for solving linear optimization problems. In this paper we present a new kernel function which yields ... 详细信息

关键词： linear optimization interior-point method primal-dual method large-update method polynomial complexity

基于耐震时程法的地下结构序列地震作用抗震性能研究

在线全文

学校读者我要写书评

暂无评论

振动与冲击 2024年第15期43卷 261-268,276页

作者：王国波王鸿杰王建宁金立国赵丁凤温州大学建筑工程学院浙江温州325035 中国机械工业集团有限公司北京100080 中国地震局地质研究所北京100029 中交上海航道勘察设计研究院有限公司上海200120

针对当前地铁地下结构抗震性能研究大多仅考虑主震影响而忽略地震后可能伴随发生的多次余震作用问题,开展了地下结构在主余震序列作用下的动力响应规律研究,选取典型两层三跨地铁车站为原型,建立了土-地下结构相互作用的有限元数值模型... 详细信息

针对当前地铁地下结构抗震性能研究大多仅考虑主震影响而忽略地震后可能伴随发生的多次余震作用问题,开展了地下结构在主余震序列作用下的动力响应规律研究,选取典型两层三跨地铁车站为原型,建立了土-地下结构相互作用的有限元数值模型,基于耐震时程法基本概念并结合我国相关抗震标准设计反应谱生成2条耐震时程曲线,构造了12条主余震序列输入,研究了地铁地下车站在主余震序列作用下的侧向变形特征以及损伤破坏规律。结果表明:耐震时程法可以作为主余震序列作用下地下结构抗震性能研究的一种新的高效方法;主震后带损伤结构的侧向变形应充分考虑主余震序列峰值强度比α影响,主震水平与破坏状态越高,则产生余震增量损伤的临界值强度比α越小,结构面临更严重破坏的风险也越高。研究成果为结构在序列型地震作用下的抗震分析与评估提供了新的思路。

关键词：地下结构主余震序列耐震时程分析地震损伤

Seismic performance of two-story subway station structures with different isolating systems

在线全文

学校读者我要写书评

暂无评论

Earthquake Research Advances 2022年第4期2卷 60-71页

作者： Haiyang Zhuang Wei Wang liguo jin Sheng Li Guoxing Chen School of Civil Engineering and Architecture East China Jiaotong UniversityNanchang330013China Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province Nanjing210009China Institute of Geotechnical Engineering Nanjing Tech UniversityNanjing210009China Institute of Geophysics China Earthquake AdministrationBeijing100081China

When the sliding bearing is fixed only at the top of the middle column of the underground structure,the cracks at the side end of the middle plate should be aggravated while the seismic damage of the mid-column should be *** enhance the seismic performance of the mid-plate,a new isolation design method has been mentioned while the elastic sliding bearings are set at the top of the mid-columns and between the side end of the mid-plate and the side wall at the same *** establishing a nonlinear finite element analysis model for the static-dynamic coupling interaction system,the seismic response characteristics of the cast-in-place station structure without a sliding bearing have been analyzed and compared with those of the station structure with the sliding bearing fixed only at the top of the middle columns,and those of the station structure with sliding bearing be fixed between the mid-plate and the sidewall at the same *** results show that the new isolation station structures suffer fewer earthquake damages at the mid-plate and mid-columns at the same time,which can improve the overall seismic performance of the subway station structure.

关键词： Subway station structure Seismic performance Elastic sliding bearing Seismic mitigation effect Numerical modelling