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NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF THE NEW METHOD OF HORSESHOE VORTEX CONTROL

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Journal of Hydrodynamics 2010年第4期22卷 572-581页

作者： liu zhi-hua XIONG ying WANG Zhan-zhi WANG Song TU Cheng-xu Department of Naval Architecture and Ocean Engineering Naval University of Engineering Wuhan 430033 China China Jiliang University Hangzhou 310018 China

The horseshoe vortex generated around the sail-body junction of a submarine has an important influence on the uniformity of the submarine wake at the propeller *** this article,the horseshoe vortex is simulated by the Detached Eddy Simulation（DES） method,and a new method to control the horseshoe vortex by vortex control baffler is *** numerical simulation shows that a kind of attached vortex,with the rotation direction opposite to that of horseshoe vortex,is generated by the vortex control *** the attached vortex,the strength of the horseshoe vortex is significantly *** wind tunnel experiment on a submarine model is carried out,and the axial velocities at the propeller disc of the submarine with and without vortex control baffler are measured by a hot wire anemometer *** is shown from the experimental results that the vortex control baffler can enhance the uniformity of the wake at the propeller disc,which helps to improve the propeller *** engineering applicability of the vortex control baffler is discussed.

关键词： submarine Detached Eddy Simulation (DES) method vortex control baffler horseshoe vortex attached vortex wind tunnel experiment

我国对外贸易扩张导致贫困化增长的倾向性分析

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国际贸易问题 2007年第9期297卷 9-14页

作者：陈晔刘志迎孙纲合肥工业大学人文学院

在经济全球化和国际贸易迅速发展的背景下,发展中国家对外贸易规避贫困化增长已经成为一个非常重要的课题。本文通过分析1995-2004年我国的进出口贸易数据,根据贫困化增长相关理论,用实证的方法验证了我国虽没有出现贫困化增长,但符合... 详细信息

在经济全球化和国际贸易迅速发展的背景下,发展中国家对外贸易规避贫困化增长已经成为一个非常重要的课题。本文通过分析1995-2004年我国的进出口贸易数据,根据贫困化增长相关理论,用实证的方法验证了我国虽没有出现贫困化增长,但符合贫困化增长的前提条件,也出现了部分贸易条件恶化的现象,有陷入贫困化增长的可能性,最后提出了我国对外贸易如何规避贫困化增长的战略选择。

关键词：贫困化增长贸易条件贸易扩张

Surgical Resection of Sternal Tumors and Reconstruction with Titanium Mesh

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Chinese Medical Sciences Journal 2011年第4期26卷 237-240页

作者： Hong-sheng liu ying-zhi Qin Shan-qing Li Li Li Yu-shang Cui zhi-yong Zhang Department of Thoracic Surgery Peking Union Medical College Hospital ChineseAcademy of Medical Sciences ＆ Peking Union Medical College Beijing 100730 China

Objective To evaluate the use of titanium mesh reconstruction after sternal tumor resection. Methods From January 2007 to January 2011, 14 patients with sternal tumors were admitted into Peking Union Medical Hospital. The clinical characteristics, surgical resection, and technique of reconstruction were reviewed. Results Of the 14 patients, 3 had a metastatic sternal tumor, the primary sites of which were as follows: hepatic carcinoma in one case (metastasis 19 years after operation), breast carcinoma in another case (metastasis 5 years after operation), and renal carcinoma in the other case (found simultaneously). Two patients showed local involvement of the sternum: 1 had thymic carcinoma, and the other had myofibrosarcoma. The remaining 9 patients had primary tumors: 4 were osteochondroma, 3 chondrosarcoma, 1 eosinophilic granuloma, 1 non-Hodgekin's lymphoma. En bloc resection of the sternal tumor was performed in all the 14 patients. The defect was repaired with the titanium mesh adjusted to the shape of the defect and fixed with the stainless steel wire. Eleven patients were followed up for a period from 2 months to 4 years, during which no translocation or broken of the titanium mesh was observed. Conclusions Radical en bloc excision remains the treatment of choice for sternal tumors. Sternum defect reconstruction using titanium mesh as a rigid replacement proves appropriate and effective.

关键词： sternal tumor en bloc resection sternal reconstruction rigid prosthetic replacement titanium mesh

Linking nutrient strategies with plant size along a grazing gradient： Evidence from Leymus chinensis in a natural pasture

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Journal of Integrative Agriculture 2016年第5期15卷 1132-1144页

作者： LI Xi-liang liu zhi-ying REN Wei-bo DING Yong JI Lei GUO Feng-hui HOU Xiang-yang National Forage Improvement Center/Key Laboratory of Grassland Resources and Utilization Ministry of Agriculture/Institute of Grassland Research Chinese Academy of Agricultural Sciences Hohhot 010010 P.R.China

St udying the changes in nutrient use strategies induced by grazing can provide insight into the process of grassland degradation and is important for improving grassland quality and enhancing ecosystem function. Dominant species in meadow steppe can optimize their use of limiting resources; however, the regulation of nutrient use strategies across grazing gradients is not fully understood. Therefore, in this study, we report an in situ study in which the impact of grazing rates on nutrient use strategies of Leymus chinensis, the dominant plant species in eastern Eurasian temperate steppes, was investigated. We conducted a large randomized controlled experiment（conducted continuously for five years in grassland plots in a natural pasture in Ha ilar, eastern Mongolia Plateau, China） to assess the effects of grazing rate treatments（0.00, 0.23, 0.34, 0.46, 0.69, and 0.92 adult cattle unit（AU） ha-1） on L. chinensis along a grazing gradient and employed a random sampling approach to compare the accumulation, allocation, and stoichiometry of C, N, and P in leaves and stems. Ou r findings demonstrated the follows：（i） The height of L. chinensis decreased with an increase in the grazing gradient, and the concentrations of C, N, and P significantly increased;（ii） the accumulation of C, N, and P per individual was negatively correlated with the concentration of aboveground tissues, suggesting that there was a tradeoff in L. chinensis between nutrient accumulation and concentration at the individual scale;（iii） the leaf-to-stem ratio of C, N, and P accumulation increased with grazing intensity, indicating a tradeoff in nutrient allocation and plant size at the individual plant level; and（iv） grazing rates were negatively correlated with the ratios of C：N and C：P in the stem; however, these ratios in leaves significantly increased with grazing intensity. Our findings suggest that L. chinensis in meadow steppe adapts to grazing disturbance through tradeoffs between plant size and

关键词： meadow steppe nutrient-use strategy overgrazing stoichiometry Inner Mongolia Leymus chinensis

Simulated and experimental study on temperature induced lens focal shifts

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Optoelectronics Letters 2019年第4期15卷 245-249页

作者： liu Xiao-zhu liu Li-na ZHOU Jian-biao SUN Liang liu ying-zhi LIANG Yan-mei Modern Institute of Optics Nankai University Tianjin 300350 China Institute of Physical and Chemical Engineering of Nuclear Industry Tianjin 300180 China

Optical lenses used in high temperature environment are usually affected by thermal lenses problems, but it is difficult to evaluate their focal shifts in practical applications. A three-dimensional single-lens model based on finite element solver was built to evaluate the focal shift in this study, when the temperature of surface was raised from the initial temperature to the specified temperature. An experimental method based on a Hartmann-Shack wavefront sensor was proposed to verify the rationality of the model. The nearly same results between simulations and experiments for N-BK7 and fused silica were obtained, which proves that it is feasible to analyze focal shifts of optical lenses by simulation methods.

关键词： Simulated experimental study temperature environment

Study on passive compensation of temperature induced thermal lenses

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Optoelectronics Letters 2020年第3期16卷 161-165页

作者： liu Xiao-zhu liu Li-na ZHOU Jian-biao SUN Liang liu ying-zhi LIANG Yan-mei Modern Institute of Optics Nankai UniversityTianjin 300350China Institute of Physical and Chemical Engineering of Nuclear Industry Tianjin 300180China

The thermal lens problem of optical system caused by high temperature environment is a common problem. Athermal design of lenses based on optical calculation software is an effective passive compensation method. But it is difficult to determine its accuracy and measure it experimentally. We describe an athermal design technology and propose a simulated scheme to verify the accuracy of this design. Three materials with negative dn/dT have been selected to compensate for the thermal lenses produced by a fused silica lens. The results show that the compensation effect of N-PSK53A is the best.

关键词： passive problem. optical

Determination of Dopamine in the Presence of Ascorbic Acid on the IrO2-Ta2O5 Type DSA Electrode

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Chinese Chemical Letters 2005年第1期16卷 64-66页

作者： Yang liu, zhi ying LI, Jing Hong LI? State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

IrO2/Ta2O5 (70%: 30%, molar ratio) electrodes (ITEs) were prepared by the thermal decomposition method. Typical “mud-cracked” surface and surface enrichment of Ta were observed. The determination of dopamine (DA) was carried out in the presence of ascorbic acid (AA). The detection limit of DA was 5×10-5 mol/L without the interference of AA.

关键词： Dopamine ascorbic acid determination DSA.

Analysis on the Evolution of Agricultural Structure about Pan-Yangtze River Delta

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Agricultural Science & Technology 2010年第7期11卷 103-105,108页

作者： DAI Jiang liu zhi-ying School of Humanities and Economics Hefei University of TechnologyHefei 230009 School of Management University of Science and Technology of ChinaHefei 230026

Starting from the definition of agricultural structure,this paper firstly analyzes the change of industrial and spatial structure of agriculture of Pan-Yangtze River Delta,then inspects the relationship between the development of economics and the evolution of agricultural structure,an the end it provides policy recommendation about the development and adjustment of agricultural structure for the future.

关键词： Pan-Yangtze River Delta Industrial structure of agriculture Spatial structure of agriculture

Modeling,Analysis and Simulation for High Voltage Vacuum Circuit Breaker with CAD/CAM System

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Computer Aided Drafting,Design and Manufacturing 2006年第1期16卷 70-74页

作者： liu Tao MA zhi-ying School of Electrical Engineering Xi＇an Jiaotong University Xi＇an 710049 China

How CAD design and simulation tools can assist in developing vacuum circuit breaker （VCB） in general is demonstrated. The electric field calculation has been widely utilized for electrical insulation design of VCB. ADAMS is applied in dynamic simulation to fulfill the complex calculation of mechanical characteristics. Satisfactory simulation results can be obtained by iteratively refining parameters of the model, and it is shown that this scheme can be used to provide a good basis for optimum design of VCB.

关键词： CAD/CAM VCB modeling dynamic simulation