主要动力

In this paper, we consider neutral functional differential equations and study the global existence of their solutions, stable subspaces and unstable subspaces of linear autonomous dynamical systems, local stable manifolds and local unstable manifolds of near hyperbolic equilibrium point of nonlinear autonomous dynamical systems, periodic solutions and oscillation of the neutral equations.

本文主要研究中立型泛函微分方程解的整体存在性，自治线性动力系统的稳定子空间与不稳定子空间、自治非线性动力系统在双曲平衡点的局部稳定流与局部不稳定流，周期解与解的振动性。

On the basis of these results, the estuarine mixing type and characteristics, and the formation and development of maximum turbidity zone, and the morphodynamics of intertidal mudflat evolution, and the effects on hydrodynamic and sediment environment caused by estuarine regulation are analyzed in detail. Finally, it is pointed out that the multi-disciplinary study, the numerical simulation and prediction by use of mathematical models, and the quantization of the hydrodynamic and sedimentary processes are the focal issues in future.

在系统总结近年主要相关研究成果的基础上，着重讨论了强潮河口的混合类型与特征、最大浑浊带的形成发育与主因、潮滩地貌的动力影响因素与演变过程、河口综合治理的特点与人类活动引起的水沙变异等问题，并指出多学科交叉、数学物理模拟与预报、水沙动力机理与过程的量化等方面是未来研究重点与方向。

The results show that the different dynamic characteristics of the two rollers caused by the non-symmetry of the high pressure grinding roll structure are the main cause leading to the power nonhomogeneity of the two rollers.

本文从动力学角度对高压辊磨机两辊动力非均匀性产生的原因进行了初步探讨和计算机仿真实验，结果表明：高压辊磨机结构的非对称性引起两个压辊不同的动态特性，这是导致两辊动力非均匀性的主要原因。

In this study, four boundary layer flows with the same mean velocity profile (the exponent of power law is 0.30) but different turbulence intensities are first simulated, the turbulence intensities at the model height are 10%, 15%, 20% and 26% respectively.

在此基础上，对不同截面不同高度的两个建筑物间的相互干扰特性进行了系统研究，主要针对建筑物间的静力、顺风向动力、横风向动力的干扰效应进行研究，然后对两个建筑物间的干扰机理进行了详细分析。

The main causes of the vibration in pipeline system are in two respects : The first is the vibrant force of the medium acted on pipeline system,i.e.exciting signal,such as the vibrant force caused by the gas flow at the compressor ′ s inlet and outlet and at the ramified and nodel points as well as the action of pig passing through pipeline bridge,etc.;The second is the response to the exciting signal,which is relating to the characteristics of the pipeline system,i.e.the rigidity,support,quality and equipments of the system besides the waveform of the exciting signal.

管道系统振动的原因主要有两方面，一是介质对管道系统产生的振动力，即激发信号，如气流在压缩机进、出口，分支节点部位产生的振动力，清管器通过管桥时对它的作用等；另一方面是对激发信号的响应，其响应除了和激发信号的波形有关外，还和管道系统本身的特征，即系统的刚度及支撑，质量及其配置等情况有关。

Many researchers have devoted their work to the development of modal analysis extraction techniques in order to obtain more reliable identification of the modal parameters. There are many damping identification methods, but each one has different merit and defect. In order to find which one is the most reliable method with respect to certain characteristics, this thesis focus on how to identify structure's damping in time domain. The following works have been done in this thesis: 1. Investigate four modal analysis methods——the LSCE Method, the Ibrahim Time Domain Method, the Time Domain Collectivity Modal Parameter Method, the Rational Fraction Polynomial Method and improve on the ITD Method in arithmetic.

本文主要做了如下工作： 1、集中研究了四种常用的模态识别方法，即最小二乘复指数法、Ibrahim时域法、时域总体模态参数辨识法及有理分式多项式法，并对ITD法在算法上进行了一定的改进； 2、建立结构动力模型，利用这四种方法在具体条件下识别结构的阻尼，并绘制相应的图； 3、讨论不同的情况下，不同的识别方法对阻尼识别精确性的影响； 4、基于业已明确的阻尼识别的精确性，根据研究的需要，指出在实际的识别过程中，如何选择最佳的识别方法以及识别过程中需要注意的问题； 5、选择最为精确的阻尼识别方法，以导师李书进教授在日本京都大学防灾研究所强震反应实验室所做的一足尺木制结构房屋的动力测试实验为实测模型，识别其阻尼； 6、在本文的最后，尽作者所知，提出了一些需要改进的地方，并对未来的研究方向给出了作者的建议。

The main content in this paper are as follows:(1) To offer the reference for the arrangement of BRBs, it must research the seismic vibration of the Reticular domes first.

本文主要进行了以下工作：(1)对网壳结构进行动力分析，研究单层K6型网壳结构的动力性能，为约束屈曲支撑的布置研究提供参考。

In order to empolder ocean resources and instruct engineering construction, this thesis synthetically analyzed regional geology, terrain, deposit sediments, hydrology, and sediments of coral reefs, have systemically studied the mechanical characteristics of calcareous sand and coral reef through indoor tests. 1. Many factors including regional engineering geology environment, hydrodynamic environment, terrain, physiognomy have been studied to evaluate their influence to coral reef engineering. It's considered that atoll reefs and table reefs are suitable for engineering construction and the reef flat on atolls is most perfect.

为了开发海洋资源，指导珊瑚礁工程建设，本文综合分析了南沙群岛区域工程地质特征、珊瑚礁地形地貌、海洋水动力环境、沉积物特征等资料，从工程地质角度对珊瑚礁各地貌单元的工程适宜性进行了评价，对礁灰岩和钙质砂进行了室内试验分析，主要研究内容和结论如下： 1、分析了珊瑚礁的区域工程地质环境、海洋水动力条件、地形地貌特征、岩土体条件等因素对岛礁工程建设的影响，对珊瑚礁的礁体类型进行了划分，结论认为可干出的环礁和台礁比较适合各类工程建设，其中环礁的礁坪是理想的工程建设场所。

This paper developed the theory of stochastic structure dynamic analysis, and studied the dynamic reliability of stochastic structure and structure optimization design based on the dynamic reliability.

本文进一步发展了随机结构动力分析的理论和方法，初步开展了随机结构系统动力可靠性分析和优化设计的研究工作，主要工作集中在以下几个方面：1。

Based on the large-scale model test on soil-pile-structure interaction, as a part of the project financed by nature science national fund, analysis of soil-foundation -structure dynamic interaction (NO.50278033), some issues about modeling of soil-structure interaction system are discussed in this thesis. These issues mainly include simulation of soil infinity, selection of dynamic constitution model of material, simulation of the changing status nonlinearity on soil structure interface, meshing, using of symmetry principle and so on.

结合国家自然科学基金课题《地基-基础-上部结构相互作用体系动力特性研究》(NO.50278033)，以大比例桩筏基础框架模型试验为基础，运用通用有限元软件MARC，首先对土—框架结构动力相互作用体系进行有限元计算建模的一些问题作了研究，主要包括粘—弹性人工边界的施加、土域范围的选取、材料本构模型的选用、土体与结构交界面上状态非线性的模拟、网格划分以及对称性的应用等。

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。