|
Abstract: Since piezoelectric resonant filter can not effectively prohibit higher-frequency harmonic,the mechanism of this problem has been discussed by means of a specific example which shows that there exists lots of undesirable resonant frequencies of
|
|
|
文摘:提出压电谐振滤波器不能很好地滤除高频谐波的问题,结合一个具体例子理论推导了压电谐振滤波器存在许多干扰谐振频率,从而不能有效滤除一些特定频率的干扰信号.为了解决这个问题,提出一种改进型的静电激励谐振滤波器.为了说明其可行性,具体分析了改进型双端固支微梁静电激励谐振滤波器,理论推导证实基于双端固支微梁的各阶振型正交的原理,通过适当调整激振电容的间距,双端固支微梁的高阶振动模态受到很好的抑制,因此这种谐振滤波器可以有效阻止滤波器中心频率的高频谐波的通过. |
|
Abstract: Since the 20th century, a great progress has been made in research on infiltration and runoff yield.
|
|
|
文摘:20世纪以来，入渗与产流研究取得了长足进展。 |
|
Abstract: Six compounds were isolated from the whole herb of Phyllanthus urinaria L..On the basis of physical and chemical properties and spectra data,they were identified as ethyl brevifolincarboxylate(1),brevifolin(2)，corilagin(3)，protocatechuic acid(4)
|
|
|
文摘:从叶下珠中分离得到6个化合物，根据理化数据和光谱方法鉴定为短叶苏木酚酸乙酯(1)、短叶苏木酚(2)、柯里拉京(3)、原儿茶酸(4)、没食子酸(5)和鞣花酸(6).其中(1)、(3)、(4)为本种植物中首次分离.根据2D-NMR修正了文献中化合物(1)和(2)的部分碳信号归属错误，归属了化合物(3)的碳氢谱数据. |
|
Abstract: Six quasi-ternary liquid-liquid equilibria systems between benzene, toluene, p-xylene, n-heptane, methyl-cyclohexane and N-formylmorpholine(NFM)+water have been determined at normal pressure and 60 ℃; the conjugate phase compositions and the con
|
|
|
文摘:用液液平衡釜测定了常压，60℃下加水N-甲酰吗啉和苯、甲苯、对二甲苯、正庚烷、甲基环己烷组分间6个拟三元体系的液液平衡，得到了拟三元液液平衡体系的共轭相组成和分配曲线；实验数据用UNIQUAC和NRTL模型进行了关联；用共轭相作图拟合法和模型参数推算法获得了各体系的褶点数据；并求得了溶剂对溶质的选择性和分配系数。 |
|
Abstract: So far as market economic countries are concerned, negotiable securities marke t has two main functions: the fusion of enterprise capital and better dispositio n in resources.
|
|
|
文摘:对市场经济国家而言，证券市场主要有两个功能：企业融资和优化资源配置。 |
|
Abstract: Software reusability and workspace management are two key factors for the large scale scientific computations and application development.Workspace management framework system is based on an object-oriented hierarchical model and provides applic
|
|
|
文摘:大型科学计算领域需要良好的应用开发和管理环境，以提高应用组件可复用性为目标，规范应用软件开发过程和计算工作流程.科学计算工作空间管理框架将应用组件作为基本对象，对其进行层次式管理，同时为应用组件开发过程提供有效的管理工具、可复用的应用框架以及基于可视语言的工作流编辑服务.它的可直接操纵的参数界面，基于对象的应用组件管理模式和数据流驱动的任务调度机制使其具有鲜明的特点. |
|
Abstract: Soil and water conservation in suburbs has different purposes and its benefits vary with its purposes.
|
|
|
文摘:由于城郊水土保持目的的多样性，其水土保持效益分析也存在着复杂性。 |
|
Abstract: Soil incubation experiments were conducted in lab to delineate the effect of soil temperature and soil water content on soil respirations in broad-leaved/Korean pine forest(mountain dark brown forest soil),dark coniferous forest(mountain brown c
|
|
|
文摘:为了研究土壤温度和土壤含水量对阔叶红松林(山地暗棕壤)、云冷杉暗针叶林(山地棕针叶林土壤)和岳桦林(生草森林土)的土壤呼吸的影响,于2001年9月在长白山进行了土壤实验.利用增加土壤样柱的含水量,将土壤含水量分为9％,、21％、30％、37％和43％5个等级,土壤样品分别在0、5、15、25和35℃的温度下保持24小时.阔叶红松林土壤在0(35℃范围内,土壤呼吸速率与温度呈正相关.在一定的含水量范围内(21％(37％),土壤呼吸随含水量的增加而升高,当含水量超出该范围,土壤呼吸速率则随含水量的变化而 |
|
Abstract: Solving a mathematical problem is a procedure of seeking out a road that links the initial state with the final state of the problem in problem space.The mathematical method is used to discuss this process.
|
|
|
文摘:数学问题的解答，是在问题空间中寻求一条由问题初始状态到目标状态的通路，用数学方法描述这一过程. |
|
Abstract: Some economic policies effecting hydropower exploitation in Chinaare discussed and six suggestions are proposed accordingly:decreasing taxes on power project; establishing reasonable formation mechanism of grid electric energe price; establishin
|
|
|
文摘:论述了影响我国水电开发的一些经济政策，并且有针对性地提出了六条建议：减轻电力项目税赋；建立合理的上网电价形成机制；建立合理的水电投资分摊机制；明确输电工程投资回收渠道；出台水电站调节效益分配办法；建立水电投资基金. |
|
Abstract: Some frontier technologies and design concepts in the development of analytical instrumentation in recent years are reviewed.
|
|
|
文摘:评述了近年来现代分析仪器发展的前沿技术和设计思想。 |
