57 research outputs found

    基于像素差值的非接触位移测量技术研究

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    针对接触式位移测量系统中,由于存在磨损或打滑等原因造成精度降低的现象,利用图像传感器,通过比较前后两帧图像像素差值的方法设计了一种非接触式位移测量系统。着重分析了该系统的测量精度,指出了非接触式测量误差的主要来源,并给出解决方案。实验结果表明,该方法可在10CM垂直距离上测量位移,平均测量误差仅有0.208%

    A method of SOC-estimate based on forecast of open-circuit voltage

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    【中文摘要】 估算锂离子动力电池荷电状态(SOC)是电池管理的一个难点,通过对电池放电曲线及恢复曲线分析,拟合出电池开路电压的计算公式,解决了动态情况下预测电池开路电压的问题,使开路电压估算SOC在电动车上使用成为可能。本文采用建立电池模型的方法,通过实验所得数据对模型进行曲线拟合,得到最优参数,并通过另外几组数据进行验证。实验结果表明,采用本方法预测精度为0.02%。 【英文摘要】 Estimate SOC of lithiun ion battery is a difficult point of battery management.This paper gives the formula of open-circuit voltage through analysing discharge curve and recovery curve,resolve the problem of forecasting open-circuit voltage,make estimate of SOC through open-circuit voltage possible.This paper uses the method of establishing battery model,use the data to make curve-fitting,and get the optimal value,the prove it with other data.The results of experiment proved that forecast accuracy is 0.02% ..

    基于H桥及SPWM调制的大功率交流恒流源

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    针对交流恒流的使用要求,提出了一种采用不对称规则采样法SPWM大功率恒流源实现方案,给出了相应的SPWM算法和硬件电路设计,实验结果表明,该方案具有速度快、精度高等特点

    抗肝纤维化中药复方研究存在的矛盾及其对策

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    文章查阅近20年文献,简要概括了中药复方抗肝纤维化研究的现状,指出研究中存在的两个主要矛盾,提出了精选优化抗肝纤维化中药小复方的研究设想。肝纤维化见于肝炎病毒、酒精、药物、血吸虫等

    17β-雌二醇的快速舒血管效应及其内皮依赖和非内皮依赖的机制

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    本实验旨在观察17β-雌二醇(17β-estradiol,E2)的快速舒血管效应并探讨其内皮依赖和非内皮依赖的作用机制。【方法】采用MyodapandMyodata血管张力仪进行体外血管灌流实验,测量鼠离体胸主动脉环等长张力。【结果】E2能浓度依赖性地快速舒张血管,浓度为10-9~10-6mol/L时,去内皮的血管环舒张程度明显小于内皮完整的血管环,而当E2浓度增加至10-5mol/L时,去内皮的血管环与内皮完整的血管环舒张程度无差异;在内皮完整的血管环,分别用左旋硝精氨酸甲酯(NG-nitro-L-arginine methyl ester,L-NAME)、亚甲蓝(methylene blue,MB)、他莫昔芬(tamoxifen)、甲基-β-环糊精(methyl-β-cyclodextrin,MβCD)预孵育均能显著抑制E2(10-6mol/L)的舒血管效应;而在去内皮的血管环,E2(10-5mol/L)能抑制CaCl2在无钙高钾溶液中诱发的血管收缩。【结论】E2的快速舒血管效应,具有内皮依赖性,与雌激素受体介导内皮释放一氧化氮(nitricoxide,NO)有关,且质膜微囊结构必须完整,而当E2浓度较高时主要是通过抑制细胞外的钙内流直接舒张血管,为非内皮依赖性

    从通道水平研究LaCl<sub>3</sub>对萝卜液泡膜的影响

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    The Report of the Supplying and Demanding Conditions of Colleges and Universities' Graduates of all Levels and Kinds

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    通过对全国高校毕业生就业率等权威数据的解读以及毕业生供需情况的分析,提出21世纪我国高等教育的发展方向,即重点高校加速发展研究生规模;普通高等学校适度发展社会急需专业本科规模,严加控制与本科专业雷同的专科专业,大力发展培养高级技工的职业技术专科。This report is about the employment condition of colleges and universities' graduates, which makes a study of the authoritative data such as the employment ratio of colleges and universities' graduate and analyzes the supplying and demanding conditions of the graduate. It puts forward the developing orientation of colleges and universities education in 21cn which including that the key institutes of higher learning should rapidly expand the graduate education;the ordinary colleges and universities should moderately develop the undergraduate education which are in dire need by society, strictly control the training specialties which are identical with the undergraduate specialties, and energetically develop the vocational education which train the technician
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