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某超高层钢管混凝土框架-核心筒结构的整体稳定性分析

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钢结构 2010年第6期25卷 35-38页

作者：尧国皇孙占琦孙素文潘东辉赵群昌清华大学土木工程系北京100084 深圳市市政设计研究院有限公司广东深圳518029 东莞理工学院广东东莞523808

采用结构分析软件SAP2000对某超高层钢管混凝土框架-核心筒结构进行线性和非线性整体稳定分析。分析结果表明,该超高层结构具有较好的整体稳定性能。基于整体稳定分析结果,对结构中底部跨层柱的计算长度系数进行计算。

关键词：超高层钢管混凝土框架-核心筒结构整体稳定性

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Localization of site-specific delivery capsule in vivo with alternating electromagnetic field

Localization of site-specific delivery capsule in vivo with ...

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Proceedings of the Biannual World Automation Congress

作者： Xitian Pi suwen zhao Hongying Liu Bin Xia Xiaoquan Shi Xiaolin Zheng Microsystem Center of Chongqing University China Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China Chongqing University Chongqing University Chongqing China College of Bioengineering Chongqing University China Chongqing University Chongqing Sichuan CN

Site-specific delivery capsule (SSDC) is a robotic capsule. It can load with drug and deliver the drug to the selected sites of human or animalspsila gut. In order to know whether the capsule have moved into the selected sites, we use receiving coils to detect the magnetic field generated by the eddy current in batteries of the capsule when the capsule exists in the alternating magnetic field. Experiment in simulative conditions of gastrointestinal (GI) tract is carried out and the result verifies the effectiveness of this method.

关键词： In vivo Electromagnetic fields Drugs Magnetic fields Robots Humans Coils AC generators Eddy currents Batteries

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Optimal Number of Secondary Users through Maximizing Utility in Cooperative Spectrum Sensing

Optimal Number of Secondary Users through Maximizing Utility...

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IEEE Conference on Vehicular Technology (VTC)

作者： suwen Wu Ming zhao Jinkang Zhu PCNSS Laboratory University of Science and Technology Hefei Anhui China

ISBN: (纸本)9781424425143

Spectrum sensing is a key technology in cognitive radio (CR) and cooperative spectrum sensing is derived due to the effects of channel fading. In this paper, we focus on the optimal number of secondary users in cooperative spectrum sensing to maximize the utility in CR network. By considering both the detection error probability and the resource used by the secondary users in cooperation, we derive the analytical suboptimal number of secondary users in a special CR network where all the SUs have the same SNR. The simulation results show that the utility of suboptimal scheme is greater than that of other schemes and nearly the same as that of the optimal scheme with exhaust search.

关键词： Chromium Cognitive radio Interference Fading Equations Error probability Signal processing Bandwidth Costs Analytical models

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A Novel Network-Coding-Based Coded Cooperation Scheme

A Novel Network-Coding-Based Coded Cooperation Scheme

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IEEE Conference on Wireless Communications and Networking

作者： suwen Wu Jinkang Zhu Ming zhao PCNSS Laboratory University of Science and Technology Hefei Anhui China

Coded Cooperation (CC) is a promising user cooperation scheme. In this paper, we propose a novel network- coding-based coded cooperation scheme. When a user decodes its partner's information correctly in the first frame, it transmits the combination of the partner's parity bits and its own parity bits through network coding in the second frame. This is distinct from the classical scheme, where the user only transmits the partner's parity bits during cooperation. We analyze the outage probability of the proposed scheme, and show that it achieves a full diversity order. Numerical evaluations reveal that the proposed scheme outperforms the classical scheme when the inter-user channels are poor. Also, the results show that the proposed scheme always outperforms no cooperation in various channel conditions while the performance of classical scheme is worse than that of no cooperation with the poor inter-user channels. This means that the performance of the proposed scheme is stabler than the classical scheme and the proposed scheme is more tolerant to the poor inter-user channels.

关键词： Network coding Decoding Performance analysis System performance Communications Society Wireless networks Bidirectional control Protection

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基于光学遥感技术获取近地面气溶胶消光系数的方法研究

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电子测量与仪器学报 2009年第9期23卷 69-73页

作者：李素文司福祺赵鑫淮北煤炭师范学院物理与电子信息学院淮北235000 中国科学院安徽光学精密机械研究所合肥230031

针对我国大气污染特点,开展基于光学遥感技术的主动差分吸收光谱法(DOAS)反演近地面气溶胶消光系数的方法研究。首先介绍了主动DOAS的工作原理,分析了基于双光路DOAS技术解析气溶胶质粒消光信息的实质,探讨了利用单光路测量气溶胶的可行... 详细信息

针对我国大气污染特点,开展基于光学遥感技术的主动差分吸收光谱法(DOAS)反演近地面气溶胶消光系数的方法研究。首先介绍了主动DOAS的工作原理,分析了基于双光路DOAS技术解析气溶胶质粒消光信息的实质,探讨了利用单光路测量气溶胶的可行性,并利用干净条件下近距离测得光强,来校正系统,解决了差分吸收光谱技术中光源绝对光强难以确定的难题。在获取气溶胶消光系数同时,基于差分思想可以获取痕量气体的大气浓度。论文最后把该方法应用于外场数据的分析中,成功地反演出气溶胶的消光系数和痕量气体浓度。

关键词：光学遥感气溶胶主动DOAS 消光系数

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Preparation and Luminescent Properties of Polymer Fibers Containing Y₂O₃:Eu Nanoparticles by Electrospinning

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JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2008年第11期8卷 6017-6022页

作者： Yu, Hongquan Song, Hongwei Pan, Guohui Fan, Libo Li, suwen Bai, Xue Lu, Shaozhe zhao, Haifeng Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Key Lab Excited State Phys Changchun 130033 Peoples R China Chinese Acad Sci Grad Sch Beijing 100039 Peoples R China

In this paper, composite fibers of polyvinylpyrrolidone (PVP) and Y2O3:Eu3+ nanocrytals were prepared by electrospinning and characterized by electron microscope, Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD). The composite fibers are in random orientation and with average diameter of similar to 300 nm and length up to several ten micrometers. The luminescent properties were investigated and compared with the pure Y2O3:Eu3+ nanocrystals. Due to certain weak interactions between nanocrystals and PVP matrix, charge transfer band in the excitation spectra show slightly red shift for the fibers relative to in the case of pure Y2O3:Eu3+ nanocrystals. The PVP polymer may modified the surface defect states of nanocrystals, yielding decreased intensity ratio of D-5(0)-F-7(2) to D-5(0)-F-7(1) transition in the emission spectra. The fluorescence lifetimes of D-5(0) level for Eu3+ in the composite fibers and Y2O3:Eu3+ nanocrystals were respectively determined to be 1.40 and 1.74 ms. The decreased fluorescence lifetime in the composite fibers was attributed to increased radiative transition rate, as result of the influence of refractive index of the surrounding PVP media instead of air.

关键词： Y2O3:Eu3+ Electrospinning Composite Fibers Luminescence

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Assignment of polar states for protein amino acid residues using an interaction cluster decomposition algorithm and its application to high resolution protein structure modeling

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PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS 2007年第4期66卷 824-837页

作者： Li, Xin Jacobson, Matthew P. Zhu, Kai zhao, suwen Friesner, Richard A. Columbia Univ Dept Chem New York NY 10027 USA Univ Calif San Francisco Dept Pharmaceut Chem San Francisco CA 94143 USA

We have developed a new method (Independent Cluster Decomposition Algorithm, ICDA) for creating all-atom models of proteins given the heavy-atom coordinates, provided by X-ray crystallography, and the pH. In our method the ionization states of titratable residues, the crystallographic mis-assignment of amide orientations in Asn/Gln, and the orientations of OH/SH groups are addressed under the unified framework of polar states assignment. To address the large number of combinatorial possibilities for the polar hydrogen states of the protein, we have devised a novel algorithm to decompose the system into independent interacting clusters, based on the observation of the crucial interdependence between the short range hydrogen bonding network and polar residue states, thus. Significantly reducing the computational complexity of the problem and making our algorithm tractable using relatively modest computational resources. We utilize an all atom protein force field (OPLS) and a Generalized Born continuum solvation model, in contrast to the various empirical force fields adopted in most previous studies. We have compared our prediction results with a few well-documented methods in the literature (WHATIF, REDUCE). In addition, as a preliminary attempt to couple our polar state assignment method with real structure predictions, we further validate our method using single side chain prediction, which has been demonstrated to be an effective way of validating structure prediction methods without incurring sampling problems. Comparisons of single side chain prediction results after the application of our polar state prediction method with previous results with default polar state assignments indicate a significant improvement in the single side chain predictions for polar residues.

关键词： protonation state mis-assignment hydrogen bond all-atom force field side chain prediction generalized born model

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Polyol-mediated syntheses and characterizations of NaYF₄, NH₄Y₃F₁₀ and YF₃ nanocrystals/sub-microcrystals

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MATERIALS RESEARCH BULLETIN 2008年第8-9期43卷 2130-2136页

作者： Qin, Ruifei Song, Hongwei Pan, Guohui Hu, Lanying Yu, Hongquan Li, suwen Bai, Xue Fan, Libo Dai, Qilin Ren, Xinguang zhao, Haifeng Wang, Tie Chinese Acad Sci Changchun Inst Opt Fine Mech & Phys Key Lab Excited State Phys Changchun Peoples R China Chinese Acad Sci Grad Sch Beijing 100039 Peoples R China

In this paper, NaYF4 nanocrystals and NH4Y3F10 sub-microcrystals were prepared using a polyol method. After being annealed, NH4Y3F10 can convert into YF3, which is a very efficient host matrix for upconversion. The structures of obtained NaYF4, NH4Y3F10 and YF3 samples are pure cubic phase, a mixture of cubic and hexagonal phase and pure orthorhombic phase, respectively. The size of obtained NaYF4 nanocrystals is about 20 nm, and those of NH4Y3F10 and YF3 sub-microcrystals are both about 200 nm. When co-doped with Er3+ and Yb3+, NaYF4 and YF3 samples can emit bright light under 978 nm excitation. Upconversion mechanisms in Yb3+/Er3+ co-doped NaYF4 and YF3 samples were discussed. (c) 2007 Elsevier Ltd. All rights reserved.

关键词： fluorides nanostructures luminescence

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Preparation and luminescent properties of YVO4:Eu3+ nanofibers by electrospinning

Preparation and luminescent properties of YVO4:Eu3+ nanofibe...

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作者： Yu, Hongquan Song, Hongwei Pan, Guohui Qin, Reifei Fan, Libo Zhang, Hui Bai, Xue Li, suwen zhao, Haifeng Lu, Shaozhe Key Laboratory of Excited State Physics Graduate School of Chinese Academy of Sciences Chinese Academy of Sciences Changchun 130033 China

This paper describes a procedure based on electrospinning for generating europium-doped yttrium vanadate (YVO4:Eu3+) nanofibers with diameters ranging from 30 to 50 nm. The YVO4-Eu3+ nano-fibers were obtained through calcining precursory nanofibers, which were prepared through the electrospinning method. Suitable electrospinning parameters, such as concentration of PVP in solution, spinneret tip-to-collector plate distance (TCD), and applied voltage between spinneret and collector plate, are used to obtain thinner and more uniform precursory nanofibers of YVO4:Eu3+, which is important for preparing smaller diameter pure YVO4:Eu3+ nanofibers. The luminescent properties of the YVO3+:Eu3+ nanofibers including excitation and emission spectra and fluorescence lifetime were studied. The excitation spectrum shows a broad band extending from 200 to 350 nm, which corresponds to the strong vanadate absorption in YVO4:Eu 3+. The emission spectrum is dominated by the red 5D 0 -→ 7F3 hypersensitive transition of Eu3+. The fluorescence lifetime of Eu3+ 5D 0 -→ 7F2 (619 nm) is determined to be 493 μs at room temperature, which is basically in accordance with that in the bulk (521 μs). Copyright © 2008 American Scientific Publishers All rights reserved.

关键词： Nanofibers

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Long loop prediction using the protein local optimization program

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PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS 2006年第2期65卷 438-452页

作者： Zhu, Kai Pincus, David L. zhao, suwen Friesner, Richard A. Columbia Univ Dept Chem New York NY 10027 USA

We have developed an improved sampling algorithm and energy model for protein loop prediction, the combination of which has yielded the first methodology capable of achieving good results for the prediction of loop backbone conformations of 11 residue length or greater. Applied to our newly constructed test suite of 104 loops ranging from 11 to 13 residues, our method obtains average/median global backbone root-mean-square deviations (RMSDs) to the native structure (superimposing the body of the protein, not the loop itself) of 1.00/0.62 angstrom for 11 residue loops, 1.15/0.60 angstrom for 12 residue loops, and 1.25/0.76 angstrom for 13 residue loops. Sampling errors are virtually eliminated, while energy errors leading to large backbone RMSDs are very infrequent compared to any previously reported efforts, including our own previous study. We attribute this success to both an improved sampling algorithm and, more critically, the inclusion of a hydrophobic term, which appears to approximately fix a major flaw in SGB solvation model that we have been employing. A discussion of these results in the context of the general question of the accuracy of continuum solvation models is presented.

关键词： loop prediction conformational sampling continuum solvation model hydrophobic

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