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国外钻井技术 1998年第1期13卷 39-46页

作者： xion.,HJ 罗梅玉

在天然裂缝性碳酸盐岩进行基岩酸化作业时对酸液有效穿透距离…

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钻采工艺研究 1996年第1期20卷 9-19页

作者：刘孝玺 xion.,HJ

本文介绍的是一种天空天然裂缝性碳酸盐岩基岩酸化的新方法和相应的计算机模型。利用这一种方法，可以预测在具有天然裂缝的碳酸盐岩进行酸化处理时的酸液穿透距离及用酸量。新模型可以模拟酸在天然裂缝中的流动情况及酸盐反应情况。在... 详细信息

本文介绍的是一种天空天然裂缝性碳酸盐岩基岩酸化的新方法和相应的计算机模型。利用这一种方法，可以预测在具有天然裂缝的碳酸盐岩进行酸化处理时的酸液穿透距离及用酸量。新模型可以模拟酸在天然裂缝中的流动情况及酸盐反应情况。在模拟期间，该模型考虑了地层温度、反应热及共离子效应对酸穿透距离的影响。根据数据模拟结果建立了一系列图表，以反映酸液穿透浓度与不同地层所需用酸量之间的关系。根据这些图表。

关键词：碳酸盐岩基岩酸化天然裂缝酸液穿透油气井

Social Capital and Total Factor Productivity： Evidence from Chinese Provinces

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China & World Economy 2017年第4期25卷 22-43页

作者： Ailun xion.Hans Westlund Hongyi Li Yongjian Pu School of Administration Chongqing Technology and Business University China KTH Royal Institute of Technology Sweden Hongyi Li Chinese University of Hong Kong Hong Kong Hunan University China (visiting) Chongqing University China

The impact of social capital on economic development has been broadly studied by scholars. However, research in the Chinese context is relatively rare. Drawing upon data from the China General Social Survey, our results suggest that the enhancing effect of social capital on total factor productivity is very limited in the case of China. The network dimension of social capital is significant only in pooled OLS estimations, and trust as well as the participation dimension of social capital exert no impact across all estimations. Our interpretation is that this is partly due to the fact that trust, values and norms formed in civil society are inherently difficult to transmit to the market sector. Besides, the impact of social capital on economic performance is undermined when physical capital plays a significant role in production. We therefore propose that the effect of social capital on economic performance is contingent on localized social and economic conditions.

关键词： economic performance social capital total factor productivity

FS-LASIK术中采用椭圆形瓣与圆形瓣的术后早期视觉质量比较

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实用医学杂志 2024年第17期40卷 2430-2434页

作者：梁雄姿张青松杨万举冷思吴海霞张明慧武汉大学附属爱尔眼科医院屈光手术科武汉430061

目的探讨飞秒激光辅助的准分子激光原位角膜磨镶术(FS-LASIK)中采用椭圆形角膜瓣与圆形角膜瓣的术后早期视觉质量差异。方法前瞻性随机临床对照研究,选取自2022年6月至2023年2月在武汉大学附属爱尔眼科医院自愿接受FS-LASIK手术的患者... 详细信息

目的探讨飞秒激光辅助的准分子激光原位角膜磨镶术(FS-LASIK)中采用椭圆形角膜瓣与圆形角膜瓣的术后早期视觉质量差异。方法前瞻性随机临床对照研究,选取自2022年6月至2023年2月在武汉大学附属爱尔眼科医院自愿接受FS-LASIK手术的患者,按就诊顺序随机分为椭圆瓣组和圆瓣组,各36例(72眼)。FS-LASIK术中分别制作椭圆形与圆形角膜瓣,并行准分子激光手术。观察术中及术后并发症;术后随访3个月,比较两组患者术后1 d、1周、1个月、3个月的裸眼视力(UCVA)与等效球镜(SE);以及两组术后3个月的调制传递函数(MTF)、斯特列尔比(SR)及总高阶像差。结果所有患者手术均顺利完成,未发生严重并发症。两组术后1 d、1周、1个月、3个月UCVA差异均无统计学意义(P> 0.05)。两组术后1 d、1周、1个月、3个月SE差异均无统计学意义(P> 0.05)。两组术后3个月的MTF、SR及总高阶像差差异均无统计学意义(P> 0.05)。结论 FS-LASIK术中采用椭圆形角膜瓣或圆形角膜瓣均可获得理想的视力,两者术后早期的视觉质量无显著差异。

关键词：飞秒激光角膜瓣视觉质量调制传递函数

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中国农产品市场对外开放的适度性研究

华南农业大学学报（社会科学版） 2016年第2期15卷 72-80页

作者：杨少文熊启泉广东石油化工学院经济管理学院广东茂名525000 华南农业大学经济管理学院广东广州510642

中国农业对外开放提高了市场福利,减轻了政府的补贴压力,但也造成粮食自给率低于安全水平。将农产品市场划分为保障粮食自给的国内保护市场和提高市场福利的国内开放市场两部分,改进市场福利最大化模型,构建反映市场福利的相对控制指数... 详细信息

中国农业对外开放提高了市场福利,减轻了政府的补贴压力,但也造成粮食自给率低于安全水平。将农产品市场划分为保障粮食自给的国内保护市场和提高市场福利的国内开放市场两部分,改进市场福利最大化模型,构建反映市场福利的相对控制指数,实证评估了1991-2012年期间基于粮食分类的不同农产品市场对外开放的适度性。结果表明,口粮市场开放适度、谷物市场开放不足、广义粮食市场开放影响安全、食物市场开放比较过度和非食用农产品市场开放严重不足。中国应基于比较优势和资源约束,针对不同农产品调整对外开放政策,做到粮食自给和市场福利的最佳组合。

关键词：农产品市场粮食自给市场福利对外开放粮食市场

Slope spectrum critical area and its spatial variation in the Loess Plateau of China

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Journal of Geographical Sciences 2015年第12期25卷 1452-1466页

作者： TANG Guoan SONG Xiaodong LI Fayuan ZHANG Yong xion.GLiyang Key Laboratory of Virtual Geographic Environment (Nanjing Normal University) Ministry of Education Nanjing 210023 China State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province) Nanjing 210023 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Ap- plication Nanjing 210023 China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science CAS Nanjing 210008 China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China

Slope spectrum has been proved to be a significant methodology in revealing geomorphological features in the study of Chinese loess terrain. The determination of critical areas in deriving slope spectra is an indispensable task. Along with the increase in the size of the study area, the derived spectra are becoming more and more alike, such that their dif- ferences can be ignored in favor of a standard. Subsequently, the test size is defined as the Slope Spectrum Critical Area （SSCA）. SSCA is not only the foundation of the slope spectrum calculation but also, to some extent, a reflection of geomorphological development of loess relief. High resolution DEMs are important in extracting the slope spectrum. A set of 48 DEMs with different landform areas of the Loess Plateau in northern Shaanxi province was selected for the experiment. The spatial distribution of SSCA is investigated with a geo-statistical analysis method, resulting in values ranging from 6.18 km^2 to 35.1 km^2. Primary experimental results show that the spatial distribution of SSCA is correlated with the spatial distribution of the soil erosion intensity, to a certain extent reflecting the terrain complexity. The critical area of the slope spectrum presents a spatial variation trend of weak-strong-weak from north to south. Four terrain parameters, gully density, slope skewness, terrain driving force （Td） and slope of slope （SOS）, were chosen as indicators. There exists a good exponential function relationship between SSCA and gully density, terrain driving force （Td） and SOS and a loga- rithmic function relationship between SSCA and slope skewness. Slope skewness increases, and gully density, terrain driving force and SOS decrease with increasing SSCA. SSCA can be utilized as a discriminating factor to identify loess landforms, in that spatial distributions of SSCA and the evolution of loess landforms are correlative. Following the evolution of a loess landform from tableland to gully-hilly region, this

关键词： digital elevation model slope spectrum critical area spatial variation independent geomorphological unit Loess Plateau

拟线性双曲方程组经典解存在区间的下界(英文)

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数学杂志 2006年第3期26卷 237-242页

作者：杨雄锋武汉大学数学与统计学院湖北武汉430072

本文利用特征线的方法,得到关于拟线性双曲方程组Cauchy问题经典解的一致先验估计.这样的估计给出了系统经典解存在区间的下界.

关键词：拟线性双曲方程组弱线性退化存在区间

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高精度转台摩擦力矩补偿控制器设计与仿真

光电工程 2008年第12期35卷 126-130页

作者：李拥军杨文淑范永坤熊皑中国科学院光电技术研究所成都610209 中国科学院研究生院北京100039

针对高精度转台在低速运行时,由于摩擦力矩的作用,跟踪精度会受到很大的影响的实际情况,本文提出将Stribeck摩擦力矩模型应用于高精度转台系统,并设计控制器,可以在线的对摩擦力矩进行辨识和补偿。该方法根据摩擦力矩模型的特点,采用前... 详细信息

针对高精度转台在低速运行时,由于摩擦力矩的作用,跟踪精度会受到很大的影响的实际情况,本文提出将Stribeck摩擦力矩模型应用于高精度转台系统,并设计控制器,可以在线的对摩擦力矩进行辨识和补偿。该方法根据摩擦力矩模型的特点,采用前馈+积分反馈设计控制器。并采用Lyapunov函数和拉萨尔一般不变性原理分析了系统的稳定性,证明在一定的条件下,可以实现渐进稳定跟踪。实验结果表明,控制器对非线性摩擦力矩具有补偿作用。

关键词：高精度转台系统摩擦力矩补偿 Lyapunov函数拉萨尔一般不变性原理

SARS Patients-derived Human Recombinant Antibodies to S and M Proteins Efficiently Neutralize SARS-Coronavirus Infectivity

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Biomedical and Environmental Sciences 2005年第6期18卷 363-374页

作者： MI-FANG LIANG RUN -LEI DU JING-ZHI LIU CHuaN LI QuaN-FU ZHANG LU-LU HAN JIAN-SHI YU SHU-MIN DuaN XIAO-FANG WANG KONG-XING WU ZHAO-HUI xion.QI JIN DE-XIN LI State Key Laboratory for Infectious Disease Control and Prevention Institute for Viral Disease Control and Prevention State Key Laboratory for Molecular Virology Chinese Center for Disease Control and Prevention 100 Yingxin Street Xuanwu District Beijing 100052 China

Objective To develop a specific SARS virus-targeted antibody preparation for emergent prophylaxis and treatment of SARS virus infection. Methods By using phage display technology, we constructed a naive antibody library from convalescent SARS patient lymphocytes. To obtain the neutralizing antibody to SARS virus surface proteins, the library panning procedure was performed on purified SARS virions and the specific Fab antibody clones were enriched by four rounds of repeated panning procedure and screened by highthroughput selection. The selected Fab antibodies expressed in the periplasma of E. coli were soluble and further purified and tested for their binding properties and antiviral function to SARS virus. The functional Fab antibodies were converted to full human IgG antibodies with recombinant baculovirus/insect cell systems and their neutralizing activities were further determined. Results After four rounds of the panning, a number of SARS-CoV virus-targeted human recombinant Fab antibodies were isolated from the SARS patient antibody library. Most of these were identified to recognize both natural and recombinant SARS spike （S） proteins, two Fab antibodies were specific for the virus membrane （M） protein, only one bound to SARS-CoV nucleocapsid protein. The SARS-CoV S and M protein-targeted Fab or IgG antibodies showed significant neutralizing activities in cytopathic effect （CPE） inhibition neutralization test, these antibodies were able to completely neutralize the SARS virus and protect the Vero cells from CPE after virus infection. However, the N protein-targeted Fab or IgG antibodies failed to neutralize the virus. In addition, the SARS N protein-targeted human Fab antibody reacted with the denatured N proteins, whereas none of the S and M protein specific neutralizing antibodies did. These results suggested that the S and M protein-specific neutralizing antibodies could recognize conformational epitopes which might be involved in the binding of virions t

关键词： SARS-CoV Phage display Human antibody

运用统计能量分析法预示空空导弹舱内动力学环境

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振动与冲击 2007年第4期26卷 140-143页

作者：聂旭涛熊飞峤国防科技大学机电工程与自动化学院长沙410073 遵义师范学院物理系贵州遵义563002

空空导弹在挂飞过程中会遇到多种冲击和振动环境的作用,对导弹结构及其内部设备的性能影响不可忽视。针对某型空空导弹,利用稳态统计能量分析法对其包含机动抖振的随机振动环境进行预示,同时采用基于冲击响应谱的瞬态统计能量分析法预... 详细信息

空空导弹在挂飞过程中会遇到多种冲击和振动环境的作用,对导弹结构及其内部设备的性能影响不可忽视。针对某型空空导弹,利用稳态统计能量分析法对其包含机动抖振的随机振动环境进行预示,同时采用基于冲击响应谱的瞬态统计能量分析法预示导弹设备舱内的高频冲击环境。计算仿真与实测结果比较表明,统计能量分析法能够较为准确地预示动力学环境。

关键词：空空导弹冲击响应谱统计能量分析动力学环境