检索结果-南通市图书馆

Seismic response control of a complex structure using multiple MR dampers: experimental investigation

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2004年第2期3卷 181-193页

作者：陈静徐幼麟瞿伟廉吴志伦 Research Center for Urban Hazards Mitigation The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina College of AutomationWuhan University of TechnologyWuhan 430070China Professor Research Center for Urban Hazards Mitigation The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Professor College of Civil Engineering and Architecture Wuhan University of Technology Wuhan 430070China Professor Research Center for Urban Hazards Mitigation The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Doctoral Candidate

This paper presents an experimental investigation on semi-active seismic response control of a multi- story building with a podium structure using multiple magnetorheological (MR) dampers manipulated by a logic control *** experiments are performed in three phases on a seismic simulator with a slender 12-story building model representing a multi-story building and a relatively stiff 3-story building model typifying a podium *** first phase of the investigation is to assess control performance of using three MR dampers to link the 3-story building to the 12-story building,in which seismic responses of the controlled two buildings are compared with those of the two buildings without any connection and with rigid *** second phase is to investigate reliability of the semi-active control system and robustness of the logic control algorithm when 2 out of 3 MR dampers fail and when the electricity supply to MR dampers is completely *** last phase is to examine sensitivity of semi-active control performance of two buildings to change in ground *** experimental results show that multiple MR dampers with the logic control algorithm can achieve a significant reduction in seismic responses of both *** proposed semi-active control system is of high reliability and good robustness.

关键词： experimental investigation complex structure multiple MR dampers logic control seismic response

Image segmentation of small defects in precision weldments with complex structure

在线全文

学校读者我要写书评

暂无评论

China Welding 2007年第1期16卷 52-56页

作者：石端虎刚铁袁媛杨双羊 State Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001

In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image processing based on Visual Basic programming method was adopted. The methods of automatic contrast and partial grey stretch were used to enhance the X-ray detection image which has relatively low contrast, then automatic threshold method was carried out to segment the two high intensity zones, and weld zones which contain the small defects was extracted. Smoothing and sharpen processing were proceeded on the extracted weld zones, and small defects in X-ray detection image of weldments with complex structure were segmented by using the method of background subtraction in the end. The effects of raster were eliminated, and because of that the image processing was only proceeded on the extracted weld zones, the calculated speed using the above provided algorithm was improved.

关键词： X-ray testing complex structure Visual Basic program small defects image segmentation

Improved Particle Swarm Optimization for Solving Transient Nonlinear Inverse Heat Conduction Problem in complex structure

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2021年第5期38卷 816-828页

作者： ZHOU Ling ZHANG Chunyun BAI Yushuai LIU Kun CUI Miao Key Laboratory of Advanced Technology for Aerospace Vehicles of Liaoning Province State Key Laboratory of Structural Analysis for Industrial EquipmentDalian University of TechnologyDalian 116024P.R.China

Accurately solving transient nonlinear inverse heat conduction problems in complex structures is of great importance to provide key parameters for modeling coupled heat transfer process and the structure’s optimization *** finite element method in ABAQUS is employed to solve the direct transient nonlinear heat conduction *** particle swarm optimization(PSO)method is developed and used to solve the transient nonlinear inverse *** investigate the inverse performances,some numerical tests are *** conditions at inaccessible surfaces of a scramjet combustor with the regenerative cooling system are inversely *** results show that the new methodology can accurately and efficiently determine the boundary conditions in the scramjet combustor with the regenerative cooling *** solving the transient nonlinear inverse problem,the improved particle swarm optimization for solving the transient nonlinear inverse heat conduction problem in a complex structure is verified.

关键词： improved particle swarm optimization transient nonlinear heat conduction problem inverse identification finite element method complex structure

Dynamic Characteristics of complex structure Under and Out of Water

在线全文

学校读者我要写书评

暂无评论

Journal of Beijing Institute of Technology 2003年第1期12卷 80-84页

作者：冯慧华廖日东左正兴荣克林 School of Mechanical and Vehicular Engineering Beijing Institute of TechnologyBeijing100081China Beijing Institute of structure and Environment Engineering Beijing100034China

To understand the dynamic characteristics of the whole period of a complex structure's launching out of water, on the basis of FEM formulations deduced for solving coupled fluid-structure problems with strong-coupled method, FE models used to simulate the structure surrounded with fluid domains are established. The modal experiment on the real structure under shallow water shows great accordance with simulating results. Based on this verification, dynamic character parameters of all FE models simulating each phase of the structure's launching out of water are abstracted with unsymmetric algorithm, which can comprehensively describe the dynamic characters of the structure in its whole working process. Conclusions drawned from these calculations are successfully applied in works of evaluating the structure's performances and reliabilities.

关键词： complex structure FEM structure-fluid coupling dynamic characteristics

Generalizable data driven full waveform inversion for complex structures and severe topographies

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第6期21卷 4025-4033页

作者： Mahdi Saadat Hosein Hashemi Majid Nabi-Bidhendi University of Tehran Institute of Geophysics

Traditionally, simplification has been used in scientific modeling practices. However, recent advancements in deep learning techniques have provided a means to represent complex models. As a result, deep neural networks should be able to approximate the complex models, with a high degree of generalization. To achieve generalization, it is necessary to have a diverse range of examples in the training of the neural network, for example in data-driven FWI, training data should cover the expected subsurface models. To meet this requirement, we porposed a method to create geologically meaningful velocity models with complex structures and severe topography. However, it is important to note that generalization comes with its own set of *** of significant variation in topography of the generated velocity models, we need to include this information as an additional input data in training of the network. Therefore, we have transformed the seismic data to a fixed datum to incorporate geometric information. Additionally, we have enhanced the network's performance by introducing a term in the network loss function. Multiple metrics have been employed to evaluate the performance of the network. The results indicate that by providing the necessary information to the network and employing computational techniques to refine the model's accuracy, deep neural networks are capable of accurately estimating velocity models in complex environments characterized by extreme topography.

关键词： Deep learning Generalization Full waveform inversion Data-driven inversion complex structure

The Bott-Chern and Aeppli Cohomologies of complex structures on S^(3)×S^(3)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2021年第4期37卷 581-587页

作者： Jing Jing WANG School of Mathematical Sciences Fudan UniversityShanghai 200433P.R.China

We calculate the dimensions of Bott–Chern and Aeppli cohomologies associated to a complex structure on S^(3)×S^(3).We express them in terms mainly of Hogde numbers.

关键词： complex structure S^(3)×S^(3) Bott–Chern cohomology Aeppli cohomology

Experimental Investigation on complex structures Machining by Electrochemical Micromachining Technology

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2010年第5期23卷 578-584页

作者：刘勇朱荻曾永彬黄绍服余宏兵南京航空航天大学机电学院

Electrochemical micromachining （EMM） technology for fabricating micro structures is presented in this article. By applying ultra short pulses, dissolution of a workpiece can be restricted to the region very close to the electrode. First, an EMM system for meeting the requirements of the EMM process is established. Second, sets of experiments is carried out to investigate the influence of some of the predominant electrochemical process parameters such as electrical parameters, feed rate, electrode geometry features and electrolyte composition on machining quality, especially the influences of pulse on time on shape precision and working end shape of electrode on machined surface quality. Finally, after the preliminary experiments, a complex microstructure with good shape precision and surface quality is successfully obtained.

关键词： electrochemical micromachining ultra short pulse working end shape surface quality complex structure

Structural insights into the assembly of human translesion polymerase complexes

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2012年第11期3卷 864-874页

作者： Wei Xie Xuan Yang Min Xu Tao Jiang National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of Sciences15 Datun RoadChaoyang DistrictBeijing 100101China The Graduate University of Chinese Academy of Sciences 19A Yuquan RoadShijingshan DistrictBeijing 100039China

In addition to DNA repair pathways,cells utilize translesion DNA synthesis(TLS)to bypass DNA lesions during *** TLS,Y-family DNA polymerase(Polη,Polκ,Polιand Rev1)inserts specific nucleotide opposite preferred DNA lesions,and then Polζ consisting of two subunits,Rev3 and Rev7,carries out primer ***,we report the complex structures of Rev3-Rev7-Rev1^(CTD) and Rev3-Rev7-Rev1^(CTD)-Polκ^(RIR).These two structures demonstrate that Rev1^(CTD) contains separate binding sites for Polκand *** BIAcore experiments provide additional support for the notion that the interaction between Rev3 and Rev7 increases the affinity of Rev7 and *** also verified through FRET experiment that Rev1,Rev3,Rev7 and Polκ form a stable quaternary complex in vivo,thereby suggesting an efficient switching mechanism where the“inserter”polymerase can be immediately replaced by an“extender”polymerase within the same quaternary complex.

关键词： translesion DNA synthesis Rev1 Polκ Polζ complex structure

Crystal structures of D-psicose 3-epimerase from Clostridium cellulolyticum H10 and its complex with ketohexose sugars

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2012年第2期3卷 123-131页

作者： Hsiu-Chien Chan Yueming Zhu Yumei Hu Tzu-Ping Ko Chun-Hsiang Huang Feifei Ren Chun-Chi Chen Yanhe Ma Rey-Ting Guo Yuanxia Sun Industrial Enzymes National Engineering Laboratory Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China Institute of Biological Chemistry Academia SinicaTaipei 115TaiwanChina CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

D-Psicose 3-epimerase(DPEase)is demonstrated to be useful in the bioproduction of D-psicose,a rare hexose sugar,from D-fructose,found plenty in *** cellulolyticum H10 has recently been identified as a DPEase that can epimerize D-fructose to yield D-psicose with a much higher conversion rate when compared with the conventionally used *** this study,the crystal structure of the *** DPEase was *** enzyme assembles into a tetramer and each subunit shows a(β/α)8 TIM barrel fold with a Mn2+metal ion in the active *** crystal structures of the enzyme in complex with substrates/products(D-psicose,D-fructose,D-tagatose and D-sorbose)were also *** the complex structures of *** DPEase with D-psicose and D-fructose,the enzyme has much more interactions with D-psicose than D-fructose by forming more hydrogen bonds between the substrate and the active site ***,based on these ketohexosebound complex structures,a C3-O3 proton-exchange mechanism for the conversion between D-psicose and D-fructose is proposed *** results provide a clear idea for the deprotonation/protonation roles of E150 and E244 in catalysis.

关键词： D-psicose 3-epimerase ketohexose complex structure