不同步的

In addition, some modifications on several computational methods are also presented. Using LMTO method the electronic structure of several systems are studied, and some results are obtained. They are: The ideal Nb (100) surface has three surface states, the multi-layer relaxed surface has two surface states. The surface energy of the ideal surface is higher than that of the relaxed surface, that means that the multi-layer relaxed surface is more stable than the former one, which supports the LEED results. The mono-layer relaxed Ag (111) surface is the most stable one among several" stable surface models"presented by several researchers. The surface energy of Ag (111) surface is higher than that of surface Ag (001), which supports some experimental results such as different reaction rate at different surface orientations for the same material. The surafce states of Si (111) surface not only locate near the Fermi level, but also in the valence band, which agrees well with Cohen's conclusion. Si (111)-H is an effective model for analysing the surface states and H adsorbed on the back surface is a good method for improving the convincingness of the results obtained on thinner slab models. The surface stability depends on three different kinds of MoSi〓(001) surfaces, the surface with mono-layer Si is the most stable one, and the surface with Mo at the first layer is the most unstable one among them. These are consistant with the Kemoda's experimental results. The valence bands of clean or K adsorbed CdTe (111) surface agrees well with the synchrotron radiation studies. The surface of CdTe (111) consists of four kinds of surface models which show different surface electronic structures and different surface structure stabilities. The conclusion agrees well with Wu's experimental work. The different absorbed alkali metals on the CdTe (111) surface give different adsorption characteristics which have relations not only with the valence electrons, but also with the core ones of the alkali metals. The electonic structures of Si-C alloys are different from that of Si-Ge alloys, and the energy band gaps of Si-C alloys do not increase linearly with Carbon concentration, our conclusion supports Alexander's results, but conflicts with Soref's one.

现分述如下： LMTO方法及其应用方面：1）通过对Nb（100）表面电子态分析发现清洁理想表面有三个表面态，多层弛豫表面有两个表面态；表面能大小说明多层弛豫表面更稳定，支持了LEED结果。2）通过对采用不同方法获得的几种不同Ag（111）表面稳定结构的表面能计算分析，给出了单层弛豫表面为Ag（111）表面的最稳定结构；从Ag（111）单层弛豫表面和Ag（001）表面的表面能比较，发现了Ag（001）表面表面能要比Ag（111）小的，表明了同种物质不同表面取向将表现出不同物理、化学性质，这是与实验中得出的结论是吻合的，3）通过对Si（111）表面态分析，不仅发现了Si（111）表面不仅具有居于费米能级附近的悬挂键所对应的表面态，而且还有很多表面态位于价带能量范围内，与Cohen等结果一致，H饱和slab模型背表面相当于增加了slab层的厚度，是一有效的变相增加slab层厚的方法，弛豫表面较清洁理想表面价带谱们低能端的少许移动，预示着总能降低，说明弛豫表面较清洁理想表面稳定。4）MoSi〓具有三种表面，从费米能级上态密度值大小得到单层Si表面最稳定，Mo原子为表层原子的表面最不稳定，双层Si原子表面居中的结论，这与Kemoda等人实验结果是一致的。5）通过对CdTe（111）表面表面电子态、表面结构稳定性及表面H、碱金属吸附的电子结构系列研究，不仅得出了CdTe（111）清洁及碱金属K吸附价带谱与同步辐射光电子谱相吻合的结果，而且发现了CdTe（111）表面具有四类不同原子近邻特征，表现出四类不同的表面结构及电子结构特征：不同表面态分布、不同的表面结构稳定性（表层原子与次层原子成三键有一悬挂键的表面要比表层原子与次层原子成一键有三悬挂键稳定（与Wu等人实验结果一致））、不同的H吸附特性。

The holistic design of the system and resolved the designs of software and hardware based on VXI bus are put forward according to the demand of test system. The hardware and software is designed, including the formation and design of hardware system, visual instrument software architecture, program design for instrument driver, high speed real-time data collection. In the dynamic test program, the idea of"software is instrument"was applied to meet the diverse test demands. Last, it is proposed that the VXI test system be developed to more totalization and networked. The basic theory of system identification was introduced briefly at first. The principle of spectrum analysis system identification based on Wiener-Hopf equation was expatiated. and the questions in applying Peusdo Random signal as spectrum analysis methods stimulate signal was studied, The generation principle of the peusdo random signal is researched, the characteristic of peusdo random are analyzed from time domain and frequency domain, the inverse repeat peusdo random signal is brought forward to make up the shortage of ordinary peusdo random signal. And a new chaos genetic algorithmis presented to solve the unprecise problem of the traditional method. In the servo valve dynamic characteristic test system, the spectrum analysis methods was applied successfully, the servo valve dynamic characteristic could be acquired rapidly and exactly, the test results were analyzed and the ameliorate methods were brought forward at last.

结合航天某集团液压测试中心测试系统的需求，提出了基于VXI总线的液压测试系统的整体设计方案，完成了测试系统的硬件设计与软件设计，包括硬件系统构成与设计、虚拟仪器软件结构、仪器驱动程序设计、高速同步实时数据采集等内容；以伺服阀动态特性测试为例设计了测试模块，该模块体现了VXI总线仪器软件开发所倡导的"虚拟仪器"的思想，以软件的灵活应用满足了不同的测试需求；结合自动测试系统的发展，研究了VXI测试系统与网络技术结合，实现各种软硬件资源共享，进一步提高设备及数据的利用率和系统的扩展性，使自动测试向综合化、网络化方向发展；研究了伪随机信号作为谱分析法辨识的激励信号时存在的问题，讨论了伪随机信号的产生机理，从频域和时域分析了伪随机信号的性质及其应用，提出了用逆重复伪随机信号弥补了普通伪随机信号的不足，并以混沌遗传算法对逆重复伪随机信号产生过程中的参数进行优化，可以更合理而不是凭经验产生需要的逆重复伪随机信号。

Due to the complexity of the cell jitter, the NonSynchronous Tining Recovery methods are currently not mature With the emphasis being given to the Class A CBR traffic, this paper analyzes the performance of the queueing delay and cell jitter at the source node and intermediate nodes, and discusses the Source Timing Recovery at the destination node in ATM networks Firstly, this paper presents a description of the cell jitter of CBR traffic, and gives the definitions of two kinds of cell jitter regarding the Source Timing Recovery for CBR traffic Then, by using exact mathematical models and analysis methods, this paper analyzes the impact of the factors, such as the capacity of the queueing buffer, the randomness, the deterministic nature and the correlation in cell arrivals of the background traffic sources, on the queueing delay and cell jitter performance of the CBR traffic through Statistical Multiplexitng To obtain an insight into the power spectral distribution and look for better schemes for the depression and filtering of the cell jitter, within the analyses we succeed deriving the power spectrum of the cell jitter for CBR traffic Hence, not only the power spectral distribution of the cell jitter can in the frequency domain be qualitatively understood, but also can the rms (root-meansquare) value of the cell jitter be quantitatively obtained so as to more accurately measure the amplitude of the jitter In the end-to-end performance analysis of the queueing delay and cell jitter, we propose a kind of quasi-periodic cell stream model to characterize the jittered CBR traffic, and present an initial queueing analysis of the CBR traffic following such a model at a generic intermediate node Additionally, we briefly discuss the buildout/playout and Source Timing Recovery functions of the destination node Finally, regarding the Source Timing Recovery of CBR traffic, this paper systematically discusses several important principles of the cell jitter filtering and depression reported in the literature, introduces several implementation schemes of the Source Timing Recovery e.

由于信元抖动的复杂性，非同步定时恢复方法目前还很不成熟。本文针对A类CBR业务流在ATM网络源节点和中间节点的排队时延和信元抖动性能，以及在目的节点的源定时恢复问题作了较为全面的研究。首先，文中描述了CBR业务流的信元抖动，并具体地给出了两种与CBR业务源定时恢复有关的信元抖动的定义。然后，采用了精确的数学模型和分析方法，有针对性地分析了业务背景中信元到达的纯随机性、确定性和相关性以及排队缓存器容量等因素对CBR业务流经过统计复用后的排队时延和信元抖动性能的影响。为了了解信元抖动的功率频谱分布和寻求更好的抑制和滤除抖动的方法，在性能分析中，我们成功地完成了CBR业务流信元抖动的功率谱分析，使得不但可以从频域定性地认识信元抖动的能量分布特性，而且还可以定量地求出信元抖动的均方根值(rms：root-mean-square)，以更为准确地衡量抖动的大小。在CBR业务流的多节点端-端排队时延和信元抖动性能分析中，我们提出了一种准周期性(quasi-periodic)信元流模型来描述感染了信元抖动的CBR业务流，并基于这一模型进行了CBR业务流中间节点的初步排队分析。

The holistic design of the system and resolved the designs of software and hardware based on VXI bus are put forward according to the demand of test system. The hardware and software is designed, including the formation and design of hardware system, visual instrument software architecture, program design for instrument driver, high speed real-time data collection. In the dynamic test program, the idea of"software is instrument"was applied to meet the diverse test demands. Last, it is proposed that the VXI test system be developed to more totalization and networked. The basic theory of system identification was introduced briefly at first. The principle of spectrum analysis system identification based on Wiener-Hopf equation was expatiated. and the questions in applying Peusdo Random signal as spectrum analysis methods stimulate signal was studied, The generation principle of the peusdo random signal is researched, the characteristic of peusdo random are analyzed from time domain and frequency domain, the inverse repeat peusdo random signal is brought forward to make up the shortage of ordinary peusdo random signal. And a new chaos genetic algorithmis presented to solve the unprecise problem of the traditional method. In the servo valve dynamic characteristic test system, the spectrum analysis methods was applied successfully, the servo valve dynamic characteristic could be acquired rapidly and exactly, the test results were analyzed and the ameliorate methods were brought forward at last.

结合航天某集团液压测试中心测试系统的需求，提出了基于VXI总线的液压测试系统的整体设计方案，完成了测试系统的硬件设计与软件设计，包括硬件系统构成与设计、虚拟仪器软件结构、仪器驱动程序设计、高速同步实时数据采集等内容；以伺服阀动态特性测试为例设计了测试模块，该模块体现了VXI总线仪器软件开发所倡导的&虚拟仪器&的思想，以软件的灵活应用满足了不同的测试需求；结合自动测试系统的发展，研究了VXI测试系统与网络技术结合，实现各种软硬件资源共享，进一步提高设备及数据的利用率和系统的扩展性，使自动测试向综合化、网络化方向发展；研究了伪随机信号作为谱分析法辨识的激励信号时存在的问题，讨论了伪随机信号的产生机理，从频域和时域分析了伪随机信号的性质及其应用，提出了用逆重复伪随机信号弥补了普通伪随机信号的不足，并以混沌遗传算法对逆重复伪随机信号产生过程中的参数进行优化，可以更合理而不是凭经验产生需要的逆重复伪随机信号。

The results indicate that in the synchronizing condition the MRF is unyielded, every point of MRF in the flow field has the same angular velocity. Under the slipping condition, with the increase of magnetic field or the decrease of slip speed, MRF may transfer from whole yield to partial yield. When the MRF wholly yields, the angular velocity of MRF increases nonlinearly with its radius, the non-linear distribution becomes more obvious as the magnetic intensity in the working gap increases. When the MRF partially yields, the yield region expands with the decrease of magnetic intensity or the increase of slip speed and the unyield region always reaches the driven rotor. The transfer torque of MRTD increases with the increase of the external magnetic field, but the transfer torque maintains a constant value approximately with the variation of slip speed at the same magnetic intensity.

研究结果表明，在同步工况下，传动装置流场中磁流变液未屈服，各点角速度相同；在滑差工况下，随外加磁场的增大和滑差转速的减小，磁流变液逐渐从完全屈服向部分屈服转变；磁流变液完全屈服时，磁流变液角速度随半径呈非线性增加，工作间隙中磁场越强，流场的非线性分布越明显；磁流变液部分屈服时屈服区域随外加磁场的增大而减小，随滑差转速的增大而增大，未屈服区与主动转子相连；稳态下磁流变传动装置传递的转矩随外加磁场的增加而近似呈线性增大，但在相同外加磁场下，传递转矩基本不随滑差转速改变而改变，表现出良好的恒转矩特性。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失