结构

Of these structures, the fcc structure, owing to its high symmetry, is only fit for close-packed lattice prepared by inverted-opal method.

三种结构中，fcc结构由于高对称性导致的能级简并，只适用于密堆积排列的反蛋白石结构；diamond结构非常容易产生高带隙率的完全禁带，并且可以通过调节多项参数得到所需的完全禁带；woodpile结构参数调节范围比较宽，为实验制备带来方便。

At present it is very difficult to predict all the RNA secondary structures. This paper describes RNA secondary structure prediction methods from 1970\' to this day in a systematic way some. Tracing back and following the tracks of prediction methods the author made a summary of RNA research progress and situation while a enumeration problem of RNA secondary structure is studied with the method of combinatorial enumeration.

目前所有有关RNA二级结构的预测算法要预测出所有序列的二级结构仍然很困难，本文系统介绍了从上世纪70年代以来发展至今的各类RNA二级结构预测算法，从对RNA结构预测方法的追溯和跟踪，对当今RNA研究的进展和形势做了一个总结，并且应用组合计数的技巧解决了一类RNA二级结构的计数问题。

Thirdly, a new type base isolation system, i. e., slide-limited friction base isolation system is presented in this paper. Based on this system, harmonic and subharmonic periodic response of S-LF subjected to harmonic motion is investigated by using Floquet theory. Dynamic response of sliding structure subjected to earthquake ground motion is calculated with a precise high order direct integration method, and the numerical results are presented in terms of maximum acceleration response spectra of supcrstructure and maximum sliding displacement response spectrum. By comparison with isolating effects of pure-friction base isolation system and resilient-friction base isolation system , it shows that the isolating characteristic of S-LF is superior to P-F and R-FBI. Through analyzing an engineering example, it is observed that the maximum inter-storey shear force and absolute acceleration of sliding structure to earthquake ground motion are very different from those of traditional structures.

提出了一种新型基础隔震模型，即带限位装置的摩擦隔震体系；基于此隔震模型，利用Floquet理论研究地面谐运动下S-LF结构的运动特性；并利用高精度的精细时程积分法，通过对地震作用下S-LF动力响应的计算，绘制了上部结构最大加速度反应谱和基底最大滑移量反应谱，并研究了各种结构参数对隔震的影响；通过与恢复力摩擦隔震系统和纯摩擦力滑移隔震系统的比较表明，S-LF的隔震性能优于P-F和R-FBI；对计算实例的分析发现，地震作用下S-LF结构的层间最大剪力和最大绝对加速度反应分布较一般传统结构有很大区别。

Dynamic response of sliding structure subjected to earthquake ground motion is calculated with a precise high order direct integration method, and the numerical results are presented in terms of maximum acceleration response spectra of supcrstructure and maximum sliding displacement response spectrum. By comparison with isolating effects of pure-friction base isolation system and resilient-friction base isolation system , it shows that the isolating characteristic of S-LF is superior to P-F and R-FBI. Through analyzing an engineering example, it is observed that the maximum inter-storey shear force and absolute acceleration of sliding structure to earthquake ground motion are very different from those of traditional structures.

提出了一种新型基础隔震模型，即带限位装置的摩擦隔震体系；基于此隔震模型，利用Floquet理论研究地面谐运动下S-LF结构的运动特性；并利用高精度的精细时程积分法，通过对地震作用下S-LF动力响应的计算，绘制了上部结构最大加速度反应谱和基底最大滑移量反应谱，并研究了各种结构参数对隔震的影响；通过与恢复力摩擦隔震系统和纯摩擦力滑移隔震系统的比较表明，S-LF的隔震性能优于P-F和R-FBI；对计算实例的分析发现，地震作用下S-LF结构的层间最大剪力和最大绝对加速度反应分布较一般传统结构有很大区别。

After investigating the evolving of tax systems in the world and the rising of income tax in developed countries, the author suggested the way to optimizing Chinese tax revenue structure is to set up a two-main-body tax system with turnover tax and income tax. The conceived outline is to augment the income taxation, to adjust the comparative proportion between turnover tax and income tax, and hence to change the distorted tax system and set up a two-main-body one, in which turnover tax and income tax can function congenially and complementally.

在分析成因、指出弊端和改革必要性后，本文通过对税制演变的规律总结和发达国家所得税上升为主体税种的过程考察，提出优化我国税种收入结构的方向是建立双主体税种结构，总体思路是在稳定流转税收入的情况下，增加所得税的规模及在税收收入中的比重，以动态的方式改善商品流转税和所得税的相对比例，改变我国税种收入结构失衡、税制功能扭曲的现状，构建一个流转税和所得税结构协调、功能互补的双主体税种结构。

After investigating the evolving of tax systems in the world and the rising of income tax in developed countries, the author suggested the way to optimizing Chinese tax revenue structure is to set up a two-main-body tax system with turnover tax and income tax. The conceived outline is to augment the incom e taxation, to adjust the comparative proportion between turnover tax and income tax, and hence to change the distorted tax system and set up a two-main-body one, in which turnover tax and income tax can function congenially and complementally.

在分析成因、指出弊端和改革必要性后，本文通过对税制演变的规律总结和发达国家所得税上升为主体税种的过程考察，提出优化我国税种收入结构的方向是建立双主体税种结构，总体思路是在稳定流转税收入的情况下，增加所得税的规模及在税收收入中的比重，以动态的方式改善商品流转税和所得税的相对比例，改变我国税种收入结构失衡、税制功能扭曲的现状，构建一个流转税和所得税结构协调、功能互补的双主体税种结构。

So far, the small high-rise residential rectangles column frame structure, special-shaped column frame structure short-leg shear wall system of seismic analysis and economic indicators relatively few reports, impact of the composite indicator .The residential structure is not conducive to residential owners and designers to grasp the scope of the application structure.

目前有关小高层住宅矩形柱框架结构体系、异形柱框架结构体系和短肢剪力墙结构体系的抗震指标和经济分析的比较报告很少，影响了人们对住宅结构体系综合指标的认识，不利于业主和设计人员对住宅结构体系应用范围的把握。

Two different Fabry-Perot cavities have been adopted: plane mirror cavity and confocal concave spherical mirror cavity.

采用了两种不同的Fabry-Perot腔体结构：平面腔镜结构和对称共焦球面腔镜结构；首先进行了理论分析，得出两种结构中折射率变化与干涉条纹变化的关系，然后分别对两种腔体结构下的测量系统进行实验研究，都可以探测到10-5量级的折射率变化量，结果基本令人满意。

A nonlinear eddy-viscosity turbulent flow model, which adopted third-order correlation of stress tensor and strain tensor, was modified and applied to flow computing of turbulent flow of internal combustion engine.

把采用了应力张量和应变张量的三阶相关关系的一个非线性涡粘度湍流模型进行修正后应用于内燃机缸内湍流流动计算，用此模型对几种ω形凹坑燃烧室内燃机汽缸内的流动进行计算，特别考查不同结构燃烧室内各处的湍能的变化，给出了燃烧室结构对缸内湍能影响结果，结果表明，凹坑结构时内燃机缸内湍能的分布和平均湍能的大小影响很大，可适当调整燃烧室结构来改变缸内湍流结构。

SRC in SDR is also discussed, and two improved structures of CIC filter are presented. The first one is a CIC decimation filter based on polyphase structure and partially sharpening technique, which is suitable for the situation where the requirements in passband attenuation is not very high while the requirements in alias suppression and operating speed are relatively high. The other one is an improved CIC-Rotated Sinc decimator which possesses improved frequency response, low operating rate and low cost in hardware as well.

研究了软件无线电中的采样率转换技术，给出两种改进的CIC滤波器结构；(1)基于多相结构和部分尖锐化的CIC抽取滤波器，该结构适用于通带衰落要求不是很高，混迭抑制和滤波速度的要求相对较高的场合(2)一种改进CIC-Rotated Sinc抽取滤波器，该结构在获得好的通阻带特性的前提下，一方面降低了整个CIC滤波器结构的工作速率，另一方面尽可能地降低硬件实现的复杂度。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。