高超声速升力体气动力气动热数值计算

升力体气动布局，由于其良好的高超声速气动特性、有效的内部空间和有益的防热特性，越来越受到气动工作者的重视，该文应用张涵信院士的NND格式思想，用数值模拟的方法对类似于美国X-33的升力体外形进行了气动力、气动热研究。特别是在粘性项的离散和表面热流率的计算中应用了散度和梯度的积分定义，避免了数值计算的奇异性，保证了通量守恒，提高了计算效率。结果表明气动热计算结果与美国同类飞行器结果接近，驻点热流率与经典理论结果一致

Thermodynamic Studies on Mechanism of Chiral Resolution by Liquid Chromatography

手性识别是分子识别的一个重要组成部分。液相色谱手性拆分机理研究有助于色谱条件的优化和新型手性固定相的设计,也有助于理解手性识别机制。本文就线性色谱与非线性色谱条件下手性拆分过程对应热力学参数的推求方法进行了评述,阐述了相关热力学参数的涵义及其在色谱保留及手性拆分机理探讨中的应用,并展望了该领域的研究前景。Chiral recognition is an important part of molecular recognition.Studies of mechanistic aspects of chiral resolution by liquid chromatography are helpful to optimize chromatographic conditions,to design novel chiral stationary phases and to understand chiral recogniton mechanisms.In this paper,the methodologies for deriving corresponding thermodynamic parameters in the chiral resolution processes by linear or nonlinear chromatography are reviewed.The meaning of correlative parameters is explained.The applications of these parameters in the studies of mechanistic aspects of retentions and chiral resolutions by liquid chromatography are expatiated,and corresponding research prospects are put forward.福建省自然科学基金(No.C0540024);; 福建省教育厅课题(No.JA05301)资

结合电子设计竞赛的“电力电子技术”课程教学改革实践

电子设计竞赛是提高学生动手能力、加强创新设计能力、增进团队合作等能力的有效手段,同时也能促进高校相关课程的改革。\"电力电子技术\"课程涉及电子技术、控制技术和电力技术,主要内容包括电力电子器件、整流电路、逆变电路、直流-直流变换、交流-交流变频、PWM控制技术及软开关等,课程实践性和工程性都很强。根据\"电力电子技术\"课程特点及存在的问题,提出相应的课程教学改革思路并加以实践,包括将\"电力电子技术\"课程与电子设计竞赛结合,把电赛题目带进课堂,通过案例式教学讲授知识点,积极动员学生参与电子设计竞赛,积累好的作品反馈于课程教学等。结果表明:结合电子设计竞赛的\"电力电子技术\"课程选课学生数有明显提升,参与电子设计竞赛的学生人数和获奖比例有一定提高

The Intersexual Differences of Sexual Dimorphism,Feeding Habits and Locomotor Performance at Different Temperatures of Southern Grass Lizard(Takydromus sexlineatus) in Zhaoqing,China

通过测量头、尾、体和胃检,研究肇庆南草蜥TAkydrOMuS SEXlInEATuS个体发育过程中两性异形和食性差异。南草蜥成体个体两性大小无显著差异,雄性头部显著大于雌性,两性头部大小异形可能是受到性选择压力的结果。雌雄个体食物生态位重叠度较高,两性生态位差异微弱,食性差异与两性头部异形无明显相关性。通过设计13种不同的环境温度,研究体温变化对南草蜥两性个体运动能力表现的影响。结果显示环境温度通过影响体温而影响南草蜥的运动表现,两性个体疾跑速均具有在低体温范围内随体温升高而加快、在高体温范围内随体温升高而降低的模式。在多数测试温度下,雄体的疾跑速均略大于雌体,但两者平均值在统计上无显著差异。体温对南草蜥的最大持续运动距离和停顿次数的影响显著,两性个体的疾跑速和最大持续运动距离呈显著正相关。雄性和雌性分别在26℃和30℃具有最佳的运动表现。Southern grass lizard( Takydromus sexlineatus) was collected from Zhaoqing,Guandong province to determine the sexual dimorphism and dietary habits by measuring the lengths of head,tail and body,and examining the items in the stomach.The results showed that there was no significant difference in body size.However,male individuals had significantly larger head size than females,which might be due to the divergent sexual selection pressure.A relatively high food niche overlap was observed between the sexes.There was little relationship between food habits and head dimorphism.By designing 13 different ambient temperatures,we determined the relationship between body temperature and locomotor performance of the adults.Ambient temperature affected locomotor performance by influencing the body temperature.Sprint speed increased with increasing body temperature at lower body temperature,while decreasing with increasing body temperatures at higher body temperatures,which was similar between the sexes.However,males ran slightly faster than females in most cases,but intersexual difference of sprint speed was not statistically significant.Body temperature also influenced the maximal move distance and pause times.Sprint speed was positively correlated with the maximal move distance.The optimal temperatures of locomotor performance differed between the sexes: about 26℃ for males and 30 ℃ for females,respectively.国家自然科学基金资助项目(31271124); 广东省自然科学基金(06300177); 广东省高等教育教学改革项目(粤财教[2012]361号); 大学生创新性实验计划项目(DC201316)共同资

The Intersexual Differences of Sexual Dimorphism,Feeding Habits and Locomotor Performance at Different Temperatures of Southern Grass Lizard(Takydromus sexlineatus) in Zhaoqing,China

通过测量头、尾、体和胃检,研究肇庆南草蜥TAkydrOMuS SEXlInEATuS个体发育过程中两性异形和食性差异。南草蜥成体个体两性大小无显著差异,雄性头部显著大于雌性,两性头部大小异形可能是受到性选择压力的结果。雌雄个体食物生态位重叠度较高,两性生态位差异微弱,食性差异与两性头部异形无明显相关性。通过设计13种不同的环境温度,研究体温变化对南草蜥两性个体运动能力表现的影响。结果显示环境温度通过影响体温而影响南草蜥的运动表现,两性个体疾跑速均具有在低体温范围内随体温升高而加快、在高体温范围内随体温升高而降低的模式。在多数测试温度下,雄体的疾跑速均略大于雌体,但两者平均值在统计上无显著差异。体温对南草蜥的最大持续运动距离和停顿次数的影响显著,两性个体的疾跑速和最大持续运动距离呈显著正相关。雄性和雌性分别在26℃和30℃具有最佳的运动表现。Southern grass lizard( Takydromus sexlineatus) was collected from Zhaoqing,Guandong province to determine the sexual dimorphism and dietary habits by measuring the lengths of head,tail and body,and examining the items in the stomach.The results showed that there was no significant difference in body size.However,male individuals had significantly larger head size than females,which might be due to the divergent sexual selection pressure.A relatively high food niche overlap was observed between the sexes.There was little relationship between food habits and head dimorphism.By designing 13 different ambient temperatures,we determined the relationship between body temperature and locomotor performance of the adults.Ambient temperature affected locomotor performance by influencing the body temperature.Sprint speed increased with increasing body temperature at lower body temperature,while decreasing with increasing body temperatures at higher body temperatures,which was similar between the sexes.However,males ran slightly faster than females in most cases,but intersexual difference of sprint speed was not statistically significant.Body temperature also influenced the maximal move distance and pause times.Sprint speed was positively correlated with the maximal move distance.The optimal temperatures of locomotor performance differed between the sexes: about 26℃ for males and 30 ℃ for females,respectively.国家自然科学基金资助项目(31271124); 广东省自然科学基金(06300177); 广东省高等教育教学改革项目(粤财教[2012]361号); 大学生创新性实验计划项目(DC201316)共同资

Thermodynamic studies on mechanism of chiral resolution by liquid chromatography

Chiral recognition is an important part of molecular recognition. Studies of mechanistic aspects of chiral resolution by liquid chromatography are helpful to optimize chromatographic conditions, to design novel chiral stationary phases and to understand chiral recogniton mechanisms. In this paper, the methodologies for deriving corresponding thermodynamic parameters in the chiral resolution processes by linear or nonlinear chromatography are reviewed. The meaning of correlative parameters is explained. The applications of these parameters in the studies of mechanistic aspects of retentions and chiral resolutions by liquid chromatography are expatiated, and corresponding research prospects are put forward

火箭发动机推力矢量测力天平的研究

在火箭发动机的研制过程中，其性能评估的手段主要是通过地面试验。地面试验要测量最重要的技术指标是发动机的推力性能。所以，发动机推力矢量的测力传感器对于地面试验尤为关键

Influence of Grain for Green Project on Rural Economic Development in Wuqi County

针对学术界就退耕还林(草)工程对农村经济发展影响的不同看法,作者试图根据吴起县1997-2008年统计年鉴数据和农户实地调研数据,运用灰色关联分析等方法,探讨退耕还林(草)工程对吴起县农村经济发展的影响及今后产业结构调整的方向。结果表明:退耕还林(草)工程的实施,改变了吴起县农用地利用结构和农村劳动力就业结构,促进了农民人均年收入的增加,改善了农村产业结构和农业内部结构,但其产业结构和农业内部结构仍需要优化升级,即加强工业、商饮业与运输业的发展,提高种植业的生产效率,深化林草业与牧业链网结构的构建,推进吴起县农村经济的可持续发展