检索结果-南通市图书馆

Comparison of various procedures for progressive collapse analysis of cable-stayed bridges

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第5期13卷 323-334页

作者： jian-guo CAI yi-xiang XU li-ping ZHUANG jian FENG Jin ZHANG Key Laboratory of C&PC Structures of Ministry of Education Southeast University Nanjing 210096 China Department of Civil Engineering Strathclyde University Glasgow UK

Alternate path(AP) method is the most widely used method for the progressive collapse analysis,and its application in frame structures has been well ***,the application of AP method for other structures,especially for cable-stayed structures,should be further *** four analytical procedures,i.e.,linear static,nonlinear static,linear dynamic,and nonlinear dynamic were firstly improved by taking into account the initial *** a cable-stayed structure was studied using the four improved ***,the losses of both one cable and two cables were *** results show that for static and dynamic analyses of the cable-stayed bridges,there is large difference between the results obtained from simulations starting with either a deformed or a nondeformed configuration at the time of cable *** static results are conservative in the vicinity of the ruptured cable,but the dynamic effect of the cable loss in the area farther away from the loss-cable cannot be ***,the dynamic amplification factor of 2.0 is found to be a good estimate for static analysis procedures,since linear static and linear dynamic procedures yield approximately the same maximum vertical *** results of the comprehensive evaluation of the cable failure show that the tread of the progressive failure of the cable-stayed bridges decreases when the location of the failed cables is closer to the pylon.

关键词： Progressive failure Structural failures Collapse linear analysis Nonlinear analysis Dynamic analysis Cable-stayed bridges

Elaborate Scene Reconstruction with a Consumer Depth Camera

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2018年第4期15卷 443-453页

作者： jian-Wei li Wei Gao yi-Hong Wu National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100080China University of Chinese Academy of Sciences Beijing 100049China

A robust approach to elaborately reconstruct the indoor scene with a consumer depth camera is proposed in this paper. In order to ensure the accuracy and completeness of 3D scene model reconstructed from a freely moving camera, this paper proposes new 3D reconstruction methods, as follows： 1） Depth images are processed with a depth adaptive bilateral filter to effectively improve the image quality; 2） A local-to-global registration with the content-based segmentation is performed, which is more reliable and robust to reduce the visual odometry drifts and registration errors; 3） An adaptive weighted volumetric method is used to fuse the registered data into a global model with sufficient geometrical details. Experimental results demonstrate that our approach increases the robustness and accuracy of the geometric models which were reconstructed from a consumer-grade depth camera.

关键词： 3D reconstruction image processing geometry registration simultaneous localization and mapping(SLAM) volumetricintegration.

Focusing with the decomposition of the time reversal operator method in noisy environments

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第7期10卷 997-1008页

作者： Chun-xiao li jian-long li Xian-yi GONG Ming-fei GUO Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China Hangzhou Applied Acoustics Research Hangzhou 310012 China MOE Key Laboratory of Mechanical Manufacture and Automation Zhejiang University of Technology Hangzhou 310014 China

This paper presents a detailed analysis of the effects of noise (reverberation) on the focusing performance of de-composition of the time reversal operator (DORT) in a noise-limited case and in a reverberation-limited case, respectively. Quantitative results obtained from simulations and experiments are presented. The results show the DORT method can be effi-ciently applied to target detection with enough source level to yield significant backscatter. For a target placed on the bottom, the influence of the reverberation on the focusing performance is slight. However, distinguishing between a target and constant backscattering returning from strong local clutter on the bottom (false alarms) needs further research.

关键词： Decomposition of the time reversal operator (DORT) Time reversal mirror Retrofocusing performance

Development of samarium–cobalt rare earth permanent magnetic materials

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2014年第6期33卷 633-640页

作者： jian-Hong yi Faculty of Materials Science and Engineering Kunming University of Science and Technology

Samarium–cobalt rare-earth（Sm–Co-RE） permanent magnetic materials with large magnetic energy product, high coercive force, high Curie temperature, good thermal stability, and corrosion resistance, have wide potential applications in aerospace, microwave communications, instrumentation, electrical engineering, magnetic machinery, etc. In this paper, the development of Sm–CoRE permanent magnetic materials in the following aspects in recent years was summarized： Sm–Co-RE permanent magnets with high application temperatures, positive temperature coefficients of coercive force, zero temperature coefficients of residual magnetization, high resistance rate,high mechanical property, and nanocrystallization.

关键词： Samarium–cobalt rare-earth permanent magnet Magnetic Temperature coefficient Resistivity

Facile Synthesis,Characterization of Flower-like Vanadium Pentoxide Powders and Their Photocatalytic Behavior

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2017年第10期30卷 1017-1026页

作者： Yao li jian-Lei Kuang yi Lu Wen-Bin Cao Department of Inorganic Nonmetallic Materials School of Materials Science and EngineeringUniversity of Science and Technology Beijing The 306 Hospital of PLA Tianjin College University of Science and Technology Beijing

In this paper, V2O5 sol was firstly prepared using vanadyl sulfate as a vanadium source by modified sol-gel method at room temperature. Then flower-like V2O5 powders were prepared by coagulating as-prepared sol with anhydrous ethanol and subsequent annealing crystallization. The X-ray diffraction analysis indicated that V2O5 powders exhibited orthorhombic crystal structure after annealing at 450 ℃. The experimental data obtained from both field emission scanning electron microscopy and high-resolution transmission electron microscopy identified that V2O5 powders were approximately flower-like in shape and about 5 μm in size. Besides, the Brunauer-Emmett-Teller specific surface area of flowerlike V2O5 powders was 24.25 m^2/g. According to Uv-Vis spectroscopy, the degradation rate of toluidine blue O（TBO） on as-prepared flower-like V2O5 powders during 10 h of visible light irradiation with an intensity of 15.4 mW/m^2 was 88%,which was faster than those over P25（46%） as a comparison. In addition, the mineralization process of TBO was investigated, which primarily consisted of demethylation and ring-opening oxidation processes, and confirmed by liquid chromatograph-mass spectrometry. The precipitation-oxidation-peptization, coagulation, and crystallization processes were proposed as the formation mechanism for the preparation of flower-like V2O5.

关键词： Vanadium pentoxide Photocatalyst Toluidine Blue O Mechanism Demethylation

A direct electrochemical biosensor for rapid glucose detection based on nitrogen-doped carbon nanocages

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2184-2192页

作者： Lan-Lan li Yu Zhao li-Jia Pan jian-Bin Xu yi Shi College of Mechanical and Electrical Engineering Henan Agricultural UniversityZhengzhou 450002China School of Electronic Science and Engineering Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210093China Department of Electronic Engineering The Chinese University of HongKongHongkong 999077China

Given the increasing number of diabetic patients,rapid and accurate detection of glucose in body fluids is *** study developed a direct electrochemical biosensor for glucose based on nitrogen-doped carbon nanocages(NCNCs).NCNCs possess a large specific surface area of 1395 m^(2)·g^(-1),a high N atomic content of 9.37%and good biocompatibility,which is favorable for enzyme loading and electron *** surface average concentration of electroactive glucose oxidase on NCNCs was 2.82×10^(-10)mol·cm^(-2).The NCNC-based direct electrochemical biosensor exhibited a high sensitivity of 13.7μA·(mmol·L^(-1))^(-1)·cm^(-2),rapid response time of 5 s and an impressive electron-transferrate constant(ks)of 1.87 s^(-1).Furthermore,we investigated an NCNC-based direct electron transfer(DET)biosensor for sweat glucose detection,which demonstrated tremendous promise for non-invasive wearable diabetes diagnosis.

关键词： Direct electron transfer(DET) Nitrogen-doped carbon nanocages(NCNCs) Glucose oxidase Biosensor

Detection of Bearing Faults Using a Novel Adaptive Morphological Update lifting Wavelet

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2017年第6期30卷 1305-1313页

作者： yi-Fan li Mingjian Zuo Ke Feng Yue-jian Chen School of Mechatronics Engineering University ofElectronic Science and Technology of ChinaChengdu 611731 China School of Mechanical Engineering Southwest JiaotongUniversity Chengdu 610031 China Department of Mechanical Engineering University ofAlberta Edmonton T6G 2G8 Canada

The current morphological wavelet technologies utilize a fixed filter or a linear decomposition algorithm, which cannot cope with the sudden changes, such as impulses or edges in a signal effectively. This paper pre- sents a novel signal processing scheme, adaptive morpho- logical update lifting wavelet （AMULW）, for rolling element bearing fault detection. In contrast with the widely used morphological wavelet, the filters in AMULW are no longer fixed. Instead, the AMULW adaptively uses a morphological dilation-erosion filter or an average filter as the update lifting filter to modify the approximation signal. Moreover, the nonlinear morphological filter is utilized to substitute the traditional linear filter in AMULW. The effectiveness of the proposed AMULW is evaluated using a simulated vibration signal and experimental vibration sig- nals collected from a bearing test rig. Results show that the proposed method has a superior performance in extracting fault features of defective roiling element bearings.

关键词： Morphological filter lifting wavelet Adaptive Rolling element bearing Fault detection

在线全文

学校读者我要写书评

暂无评论

提高采收率的注气实验评价体系

新疆石油地质 2002年第5期23卷 408-410页

作者：郭平刘建仪李士伦孙良田李闽西南石油学院特殊气藏开发重点研究室四川南充637001

注气与常规的水驱及其它驱动方式相比有较大的特殊性,近年来由于各种气源的大量发现,越来越多的油田开发探索注气提高采收率的可行性问题。然而目前还未见到系统评价、配套实验及在开发中的应用方面的文献。根据多年研究的经验和国内外... 详细信息

注气与常规的水驱及其它驱动方式相比有较大的特殊性,近年来由于各种气源的大量发现,越来越多的油田开发探索注气提高采收率的可行性问题。然而目前还未见到系统评价、配套实验及在开发中的应用方面的文献。根据多年研究的经验和国内外相关的报道,首先对注气相关配套实验及研究目的进行简要介绍,然后对不同种类的油田和注入介质的实验内容进行分析,为现场注气、室内评价实验内容的设置及研究提供参考。

关键词：注气采收率评价储集层流体相态固相沉积

Squeezing microwaves by magnetostriction

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第5期10卷 208-214页

作者： Jie li yi-Pu Wang jian-Qiang You Shi-Yao Zhu Interdisciplinary Center of Quantum Information Zhejiang Province Key Laboratory of Quantum Technology and Deviceand State Key Laboratory of Modern Optical InstrumentationSchool of PhysicsZhejiang University

Squeezed light finds many important applications in quantum information science and quantum metrology,and has been produced in a variety of physical systems involving optical non-linear ***,we show how a non-linear magnetostrictive interaction in a ferrimagnet in cavity magnomechanics can be used to reduce quantum noise of the electromagnetic *** show optimal parameter regimes where a substantial and stationary squeezing of the microwave output field can be *** of the scheme is within reach of current technology in cavity electromagnonics and *** work provides a new and practicable approach for producing s queezed vacuum states of electromagnetic fields,and may find promising applications in quantum information processing and quantum metrology.

关键词： squeezing of quantum noise cavity magnonics magnomechanics