结构单元

The concept of topology optimization of truss structures with discrete variables including two kinds of variables and the relative difference quotient algorithm for discrete optimization are extended to the topology optimization of plate and shell structures composed by plate and shell elements.

将包含两类变量的桁架结构拓扑优化设计的概念及求解离散优化的相对差商法进一步推广到由板壳单元组成的板壳结构的拓扑优化，建立了包含两类变量的板壳结构拓扑优化设计模型，并采用相对差商算法进行求解。

in this paper,a new variable interpolated filter in dvb-s(digital vidoe broadcast by satellite) is introduced based on the common filter of cascaded integrator comb.firstly a cic filter module with interpolation factor 2 is designed,then we could reuse the basic module according to the interpolation factor.based on the theory of cic filter,the filter with fpga is simulated and synthesized,the results is given,and realizes it in the system of dvb-s.

摘 要：在数字上变频中常用的cic滤波器的基础上，提出了一种适用于dvb-s系统的可变插值率cic滤波器的实现结构，首先实现一个内插因子为2的cic滤波器单元，然后根据不同的内插因子要求，来重复地调用这些内插因子为2的基本滤波器模块，这种cic滤波器的实现结构符合结构化的设计思想。

Xi′an Node Science Technology Co.Ltd.,Xi′an,710075,ChinaAbstract:In this paper,a new variable interpolated filter in DVB-S(Digital Vidoe Broadcast by Satellite) is introduced based on the common filter of cascaded integrator comb.Firstly a CIC filter module with interpolation factor 2 is designed,then we could reuse the basic module according to the interpolation factor.

摘 要：在数字上变频中常用的CIC滤波器的基础上，提出了一种适用于DVB-S系统的可变插值率CIC滤波器的实现结构，首先实现一个内插因子为2的CIC滤波器单元，然后根据不同的内插因子要求，来重复地调用这些内插因子为2的基本滤波器模块，这种CIC滤波器的实现结构符合结构化的设计思想。

The variation of the strength of lithosphere has important significance to probe continental tectonics and dynamics.

大陆岩石圈的流变学结构、力学结构、热结构比大洋的复杂得多，而且在长期构造演化过程中，也使不同构造单元的岩石圈强度发生很大变化。

The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.

基于TSUPREM4和MEDICI软件的模拟和结构性能的分析，设计单元结构并选取结构参数。

In this paper, in cognizance of the lack of accuracy of the calculation results in the current method of seismic analysis for the frame structures, the paper is searching for a new approach, using continuous models and through the establishment of the partial differential equations to carry on the dynamic analysis of the fiame structures, the limited units will be expanded to the unlimited units, each component as a continuous unit to deal with without the need of further subdivision, making the structure of dynamic behavior closer to the actual behavior and to improve the accuracy of the results.

本文针对当前框架结构抗震分析的动力时程法计算结果不精确的不足，寻求一种采用连续模型并通过建立偏微分方程来对框架结构进行动力分析的新方法，把每个构件作为一个连续单元来处理而不需要再细分，使得结构的动力行为与实际更为接近，从而提高计算结果的精度。

The mapping between performance knowledge unit and mechatronical product structural is set up.According to the perfect mapping relationship,superfluous mapping relationship and coupling mapping relationship,the solution of mechatronical product design problem is proposed.

在机电产品性能知识语义描述的基础上，扩展出机电产品性能需求集的语义描述方法，建立结构性能知识单元与机电产品实例结构的映射关系，分别根据理想、冗余和耦合映射关系，提出机电产品结构设计的求解方法。

For the raft, an isoparametric element method and VoigtKelvin model are adopted, which can be used to derive viscoelastic element stiffness matrices, a reform of successive approximation of Rayleigh Quotient is used to solve the eigenvalue problem of the composite structure.

对于筏架结构，采用Voiget-Kelvin模型及等参元法，推导了约束阻尼层单元的刚度阵及将Rayleigh商的迭代步骤加以改进的方法来进行特征分析；对于艇体结构与声学介质耦合部分，采用艇体结构的"干"模态作坐标变换。

Considering the behaviors of unbonded prestressed concrete beams and steel reinforced concrete columns, a kind of nonconforming beam-column element was constructed and the analysis precision was improved. Loading and reloading paths were introduced into the constitutive relationship of concrete. It is helpful to the analysis program to trace the full-range mechanical behavior of structures including the descending part and the hysterisis characteristic under cyclic loading.

考虑无粘结预应力混凝土梁、型钢混凝土柱等结构构件的受力特点，构造非协调梁柱单元，提高了分析精度；混凝土的本构关系中，引入卸载路径和再加载路径，使得分析程序可以追踪包括下降段在内的结构全过程力学行为，以及反复荷载下结构的滞回特性。

This thesis shows the structural damage of a steel truss girder model bridge by changing its unit rigidity.

通过改变钢桁梁模型桥单元刚度模拟其结构损伤，利用有限元结构动力分析程序对该模型桥在"损伤"前后进行了结构动力分析。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。