拓扑结构

Remarkable is that this more than a century ago almost directly with the achievement of modern mathematics, the following methods, the general flow is concepts, algebra to geometry closely linked, he and his successors -- Beiertelami, Christopher Tuofeier, Lee Puxici developed differential Zhang volume analysis has gradually become more research on the flow geometry and analysis of an important tool.

令人赞叹的是，这一个多世纪前的成就几乎直接同现代数学中的拓扑方法、一般流形概念、代数几何学等紧密相连，他和他的接班人——贝尔特拉米、克里斯托费尔、李普希茨所发展的微分张量分析逐渐成为研究流形上几何结构和分析的一个重要工具。

Also, we can present the geometric representation of biological sequences and structures. So the genometric topology and group theory are important also.

同样我们可以用几何方法来表示生物序列和二级结构，几何拓扑和群论也发挥了很大的作用。

On the basis of this method, by using GID software, a set of new software of three-dimensional structural topology optimization is developed.

在该方法研究基础上，结合GID 软件，开发了三维结构拓扑优化软件。

A method to optimize the topology of grillage structure with stress constraints is presented.

提出一种应力约束下的格栅结构的拓扑优化方法。

This topology, combining four switches with double half-wave rectifier and using variable frequency control mode with a refined small times together, achieves the effect of Zero Voltage Switching and the effect of Zero Current Switching by the resonance of resonant capacitance, resonant inductor and the magnetic inductor of the transformer.

该拓扑是一种四开关和双半波组合的结构，采用固定死区的互补调频控制方式，充分利用电路本身的特征，通过谐振电感、谐振电容和变压器的激磁电感谐振，实现零电压开关和零电流开关。

This topology, combining four switches with double half-wave rectifier and using variable frequency control mode with a refined small times together, achieves the effect of Zero Voltage Switching and the effect of Zero Current Switching by the resonance of resonant capacitance, resonant inductor and the magnetic .

该拓扑是一种四开关和双半波组合的结构，采用固定死区的互补调频控制方式，充分利用电路本身的特征，通过谐振电感、谐振电容和变压器的激磁电感谐振，实现零电压开关和零电流开关。

In order to optimize performances of shunt active power filter of harmonic compensation, attenuation ratio for switching ripple, stability and power losses, an improved LCL filter topology was presented based on the analysis of the frequency characteristics of the LCL filter, in which a switching-ripple shunt branch and a series-inductor were adopted to the damping resistor to reduce the power losses dramatically.

为了使并联有源滤波器谐波电流补偿性能、开关纹波衰减率、系统稳定性和功率损耗等方面性能得到系统的折中和优化，提出了一种改进型LCL滤波器拓扑，该结构充分利用了LCL滤波器的频率特性，在阻尼电阻两端引入开关纹波谐振分流支路，同时在阻尼电阻上串联一小电感，有效的减少了阻尼电阻的损耗而不改变系统的静态和动态性能。

It is suggested that the special electronic structure (3d〓4s〓) of Cu plays a crucial role in promoting the formation of the heptagon defects connected with the branching structures.

对铜催化产生七元环拓扑缺陷的机理进行了初步探讨，提出了铜原子特殊的价电子结构（3d〓4s〓）促成七元环形成的新观点。

Consequently, a series of important topological indices such as σ-index(Merrifield-Simmons index), Clar number, the number of Kukule structures, and the first Herndon number are obtained.

给出了他们对应的独立集多项式和Clar覆盖多项式的简单显式表示，进而从中获得了一系列重要的拓扑指标：σ-指标(Merrifield-Simmons指标)，Clar数，Kekule结构数和第一Herndon数。

Because of the limitation the former control topologies usually have, people proposed HyperCube and researching widely on it.

因为以往的控制拓扑具有较大的局限性，近年来超立方体结构被提出并得到了广泛的研究。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。