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生物多样性 1994年第B11期2卷 75-87页

作者： JEFFREY A. McNEELY chief Biodiversity officer IUCN 1196 Gland Swizerland

Axisymmetric wave propagation in gas shear flow confined by a rigid-walled pipeline

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Chinese Physics B 2015年第4期24卷 246-256页

作者：陈勇黄奕勇陈小前白玉铸谭晓栋 College of Aerospace science and Engineering National University of Defense Technology Department of Electronic Technology Officer's College of CAPF

The axisymmetric acoustic wave propagating in a perfect gas with a shear pipeline flow confined by a circular rigid wail is investigated. The governing equations of non-isentropic and isentropic acoustic assumptions are mathematically deduced while the constraint of Zwikker and Kosten is relaxed. An iterative method based on the Fourier-Bessel theory is proposed to semi-anaiyticaily solve the proposed models. A comparison of numerical results with literature contributions validates the present contribution. Meanwhile, the features of some high-order transverse modes, which cannot be analyzed based on the Zwikker and Kosten theory, are anaiyzed

关键词： wave propagation shear flow thermoviscous gas Fourier-Bessel theory

Flow aeroacoustic damping using coupled mechanical electrical impedance in lined pipeline

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Chinese Physics B 2015年第5期24卷 410-414页

作者：陈勇黄奕勇陈小前白玉铸谭晓栋 College of Aerospace science and Engineering National University of Defense Technology Department of Electronic Technology Officer’s College of CAPF

We report a new noise-damping concept which utilizes a coupled mechanical-electrical acoustic impedance to attenuate an aeroacoustic wave propagating in a moving gas confined by a cylindrical pipeline. An electrical damper is incorporated to the mechanical impedance, either through the piezoelectric, electrostatic, or electro-magnetic principles. Our numerical study shows the advantage of the proposed methodology on wave attenuation. With the development of the micro-electro-mechanical system and material engineering, the proposed configuration may be promising for noise reduction.

关键词： aeroacoustics mechanical-electrical impedance wave propagation uniform flow

Estimation of key rate after setting dead time

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Chinese Physics B 2012年第6期21卷 6-9页

作者：刘东银振强王双王粉梅陈巍韩正甫 Key Laboratory of Quantum Information of the Chinese Academy of sciences University of Science and Technology of China Army officer Academy of PLA

The estimation of key rate is an important aspect of the quantum key distribution process, especially in the use of dead time. In this paper, we demonstrate a numerical simulation to estimate the average detection probability and the key rate. Using our method, the estimated average detection probability is better than the previous result. Besides, we can easily find the best dead time, especially when considering the impact of after pulse.

关键词： dead time key rate quantum key distribution

Sensor selection of helicopter transmission systems based on physical model and sensitivity analysis

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Chinese Journal of Aeronautics 2014年第3期27卷 643-654页

作者： Lyu Kehong Tan Xiaodong Liu Guanjun Zhao Chenxu science and Technology on Integrated Logistics Support Laboratory National University of Defense Technology Department of Electronic Technology Officer’s College of CAPF

In the helicopter transmission systems, it is important to monitor and track the tooth damage evolution using lots of sensors and detection methods. This paper develops a novel approach for sensor selection based on physical model and sensitivity analysis. Firstly, a physical model of tooth damage and mesh stiffness is built. Secondly, some effective condition indicators （Cls） are presented, and the optimal Cls set is selected by comparing their test statistics according to Mann-Kendall test. Afterwards, the selected CIs are used to generate a health indicator （HI） through sen slop estimator. Then, the sensors are selected according to the monotonic relevance and sensitivity to the damage levels. Finally, the proposed method is verified by the simulation and experimental data. The results show that the approach can provide a guide for health monitor- ing of helicopter transmission systems, and it is effective to reduce the test cost and improve the system＇s reliability.

关键词： Condition indicators Health indicator Helicopter transmissionsystems Mann-Kendall test Physical model Sensitivity analysis Sen slop estimator Sensor selection

Dye-sensitized Solar Cells with Higher J_(sc) by Using Polyvinylidene Fluoride Membrane Counter Electrodes

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Nano-Micro Letters 2011年第3期3卷 195-199页

作者： Xiaodong Li Dingwen Zhang Si Chen Heng Zhang Zhuo Sun Sumei Huang Xijiang Yin Engineering Research Center for Nanophotonics and Advanced Instrument Ministry of Education Department of Physics East China Normal University Advanced Materials Technology Centre Office of the Chief Technology Officer Singapore Polytechnic

A flexible counter electrode(CE) for dye-sensitized solar cells(DSCs) has been fabricated using a micro-porous polyvinylidene fluoride membrane as support media and sputtered Pt as the catalytic ***-conventional structure DSCs have been developed by the fabricated CEs. The Pt metal was sputtered onto one surface of the membrane as the catalytic material. DSCs were assembled by attaching the Ti O2 electrode to the membrane surface without Pt coating. The membrane was with cylindrical pore geometry. It served not only as a substrate for the CE but also as a spacer for the DSC. The fabricated DSC with the flexible membrane CE showed higher photocurrent density than the conventional sandwich devices based on chemically deposited Pt/FTO glass, achieving a photovoltaic conversion efficiency of 4.43%. The results provides useful information in investigation and development of stable, low-cost, simple-design, flexible and lightweight DSCs.

关键词： Polyvinylidene fluoride Counter electrode Flexible Dye-sensitized solar cell

Passively Q-switched Nd^(3+):YAG laser with corner cube

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Chinese Optics Letters 2006年第6期4卷 332-335页

作者：高伟清姚功民许立新程勇明海谢建平 Department of Physics University of science and Technology of China Optics Teaching and Research Room of Ordnance Noncommissioned officer School

A passively Q-switched Nd^3＋：YAG laser with corner cube is theoretically and experimentally studied, We analyze the polarization variation in cavity and simulate the peak power, pulse energy and pulse width changed with the rotation angle of corner cube numerically, An experiment is made to verify the theoretical results. With rotating the angle of corner cube about the axis the variation range of peak power is 1,77 MW （from 10.36 to 8.59 MW）, and that of pulse energy is 14.9 mJ （from 159.5 to 174.4 mJ）, the fluctuation of pulse width is 2.95 ns. The experimental results agree with the theoretical analysis to the extent of variation rules. The most dynamic to static energy ratio of 62.5% is achieved.

关键词： Computer simulation Polarization Rotation

Mining Frequent Closed Itemsets in Large High Dimensional Data

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Journal of Donghua University(English Edition) 2008年第4期25卷 416-424页

作者：余光柱曾宪辉邵世煌 College of Information sciences and Technology Donghua University Department of Computer science College of Hubei Police Officer

Large high-dimensional data have posed great challenges to existing algorithms for frequent itemsets *** solve the problem,a hybrid method,consisting of a novel row enumeration algorithm and a column enumeration algorithm,is *** intention of the hybrid method is to decompose the mining task into two subtasks and then choose appropriate algorithms to solve them *** novel algorithm,i.e.,Inter-transaction is based on the characteristic that there are few common items between or among long *** addition,an optimization technique is adopted to improve the performance of the intersection of *** on synthetic data show that our method achieves high performance in large high-dimensional data.

关键词： frequent closed Itemsets large highdimensional data row enumeration column enumeration hybrid method

Exploration of Nonlinear Modeling Techniques to Predict the Retention Time of Organic Pollutants in Natural Water and Wastewater

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Chinese Journal of Structural Chemistry 2012年第11期31卷 1580-1588页

作者： Zolfaghar Mehdizadeh Hamid Reza Lotfizadeh S.S.Mortazavi Hadi Noorizadeh chief Executive officer and Head of Ilam Regional Water Company Iran Faculty of science Ilam Branch Islamic Azad University Ilam Iran Young Researchers Club Hamedan Branch Islamic Azad University Hamedan Iran Department of Chemistry Faculty of Sciences Arak Branch Islamic Azad University Arak Iran

Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. Genetic algorithm and kernel partial least square （GA-KPLS） and Levenberg- Marquardt artificial neural network （L-M ANN） techniques were used to investigate the correlation between retention time （tR） and descriptors for 150 organic contaminants in natural water and wastewater, which are obtained by gas chromatography coupled to high-resolution time-of-flight mass spectrometry （GC-TOF MS）. The L-M ANN model gave a significantly better performance than the GA-KPLS model. This indicates that L-M ANN can be used as an alternative modeling toot for quantitative structure-retention relationship （QSRR） studies.

关键词： water samples organic pollutants gas chromatography time-of-flight massspectrometry QSRR Levenberg-Marquardt artificial neural network

Developing in vitro test methodologies sufficient for chemical safety assessments in the 21 st century

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Developing in vitro test methodologies sufficient for chemic...