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Search Results: 1 - 10 of 88936 matches for " 高坚新 "
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有限长压电层合简支板自由振动的三维精确解
,沈亚鹏,王子昆
力学学报 , 1998, DOI: 10.6052/0459-1879-1998-2-1995-113
Abstract: 基于三维弹性理论和压电理论,导出了有限长矩形压电层合简支板的动力学方程及相应的边界条件,给出了一种求解压电层合板自由振动三维精确解的方法;分析了正、逆向压电效应对层合板振动频率的影响.本文所述的方法和结果对于求解其他三维动态问题,验证、比较其他简化模型、有限元计算结果以及工程应用都有指导意义.
GNSS多频观测值线性组合研究
郭忠臣,井祥,,
大地测量与地球动力学 , 2015, DOI: 10.14075/j.jgg.2015.03.004
Abstract: ?以Galileo四频为例,组合其不同频率间的相位观测值,给出以周为单位和以m为单位的相位组合观测模型的通用形式,系统分析组合后的电离层误差、波长以及观测噪声|在保持整周模糊度整数特性的前提下,研究电离层误差小、波长长、观测噪声小的组合|最后,按照合适的原则,编程计算出不同导航系统不同形式的组合观测系数,并给出几组典型组合。
THREE DIMENSIONAL EXACT ANALYSIS FOR FREE VIBRATION OF SIMPLY SUPPORTED PIEZOELECTRIC COMPOSITE LAMINATES 1)
有限长压电层合简支板自由振动的三维精确解

Gao Jianxin,Shen Yapeng,Wang Zikuen,
,沈亚鹏,王子昆

力学学报 , 1998,
Abstract: In recent years, piezoelectric materials have been widely used as sensors and actuators in structural shape control, vibration suppression,noise attenuation and damage monitoring. Exact study can provide better understanding of the mechanical and electric behaviors of piezoelectric structures. An analysis for the three dimensional solutions of piezoelectric laminated plates has been conducted by several researchers. The exact solution methods, used in the papers before, mostly follow the strategy of Pagano. This approach has been proven effective to static problems, but it is very complicated for the three dimension dynamic problems of finite long piezoelectric laminated plates. In this paper, free vibration of a finite long simply supported rectangular piezoelectric composite laminates has been studied on the basis of three dimensional linear elasticity and piezoelectricity without any simplification. The laminates can be composed of an arbitrary number of elastic and piezoelectric layers of orthotropic materials. The solution to the derived governing differential equations is obtained by the power series expansion method. The results show that the present approach is more effective than Pagan method mentioned above. Different boundary conditions are investigated to model the direct and inverse piezoelectric effects. The natural frequencies of free vibration are investigated, also. The obtained results can not only be used to assess various approximate theories, but also enhance the understanding of the dynamic behavior of piezoelectric structures.
信阳冬凌草甲素和乙素的结构研究
孙汉董,林中文,,,增义
化学学报 , 1985,
Abstract: 从河南省信阳地区产冬凌草叶中分得两种新的对映一贝壳杉烯型二萜化合物,命名为信阳冬凌草甲素和乙素,经光谱和化学方法证明,它们的结构分别为1和2。
某四缸汽油机气缸盖气缸体组合结构有限元分析
Finite Element Analysis of the Combination Structures for Cylinder Head and Block of A Four-cylinder Gasoline Engine

张晓奇,,曾志,文志,陈昆鹏
- , 2015,
Abstract: 建立了某四缸汽油机气缸盖、缸体、主轴承盖等零件的三维有限元组合模型。使用有限元分析软件Abaqus,在考虑各组件非线性接触关系的基础上,计算了该组合体在标定工况下的振动响应。对该发动机进行了表面振动测量,通过振动测点处实验数据与该点处计算数据的对比验证了有限元模型建立的合理性。分析了爆发工况下缸体、缸盖火力面及缸孔的振动变形。结果表明:缸体裙部刚度较弱容易产生变形;缸盖火力面鼻梁区变形较大,缸盖火力面与气缸盖连接处容易产生较大的应力;缸孔的变形量较小在工程允许的范围之内。
The integrating finite model for cylinder head, cylinder block and main bearing cap was established, the nonlinear contact boundary conditions were employed by using Abaqus software. The vibration response of the assembly under the rated speed was calculated, and the computed results were compared with the testing results. It shows that the finite model is rational. The deformation of cylinder block, cylinder head fire surface and cylinder hole was analyzed at the maximum firing pressure. The results show that the stiffness of cylinder body skirt is small; the deformation of the central area of cylinder head fire surface is large, the stress in the connection region between cylinder head fire surface and cylinder head is large; the deformation of cylinder hole is small and in engineering allowance
汽油机停缸扭振特性分析
Analysis on Torsion Vibration Characteristics of Gasoline Engine with Cylinder Deactivation

强强,,曾志,张良良,边强,文志
- , 2015,
Abstract: 为了研究4缸直列汽油机停缸工作的曲轴轴系扭振特性,采用多体动力学软件AVL-EXCITE Designer建立曲轴系统模型,并通过实验数据校核了模型。开展了20%~40%负荷下不同停缸方案的曲轴扭振特性仿真研究。结果表明:停缸后曲轴系统扭转角位移显著增加,角位移以低阶滚振为主;对于4缸直列汽油机而言,曲轴两端两缸停缸方案的扭振特性优于中间两缸停缸方案。
In order to investigate the torsional vibration characteristics of inline 4-cylinders gasoline engine working with cylinder deactivation and explore the best cylinder deactivation schemes,a crankshaft model is established with the multi-body dynamics software AVL-EXCITE Designer and is validated by experiments. Different cylinder deactivation schemes under 20%~40 of engine load are simulated respectively. The result makes clear that the torsional vibration angle displacement amplitude of the crankshaft under cylinder deactivation increases significantly,which is mainly composed of low order rolling vibrations. For inline 4-cylinders gasoline engine, the crankshaft torsion vibration characteristics of two cylinders with deactivation on both ends is better than the middle two cylinders with deactivation
非线性微分系统的反射函数与周期解
,周正
四川师范大学学报(自然科学版) , 2011,
Abstract:
水牛精液细管冷冻试验

牲畜兽医学报 , 1979,
Abstract:
用加速混沌优化算法求解不确定多属性决策问题
协平?
计算机科学 , 2002,
Abstract: 一、引言  混沌是非线性系统中普遍存在的一种运动.混沌的特点可以归纳为规律性、随机性和遍历性,因此利用这些特点进行混沌优化搜索不仅可避免搜索陷于局部极小,而且计算方便,比随机搜索具有更大的优越性.……
李超代数OSP(1,2)的Racah系数的求和规则和循环关系

科学通报 , 1989,
Abstract: 1。求和规则 对OSP(1,2)Racah系数R(…),我们给出如下三个求和规则: (1) 二重耦合求和规则,它是形式
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