查询词典 variable density system

The following exciting results are revealed: 1 When considering the influence of some nonlinear elements such as hard-limit of exciters, the effects of some devices such as Power System Stabilizer and Static Var Compensator which can introduce positive damping in power system, the reasonability of system parameter values in simulation, the SNB surface and HB surface on the boundary of SSSR will turn close to each other and even coalesce together; 2 Under some conditions, coupling between slow exciters and shunt capacitors will bring negative damping in power system dynamics, which increases the possibility of oscillatory instability. So the power system with mass shunt compensators is easily subjected to the oscillatory instability. In recent years, chaotic phenomena of power system have been reported many times. Some simulation studies even found chaos existing inside the power system SSSR. In this dissertation, chaotic phenomena in power systems are thoroughly studied in order to make clear the relation of chaos and SSSR. The following results are derived: 1 Based on Li-Yorke Theorem and their definition on the chaos, the existence of chaos in power system is verified; 2 Three possible routes of causing chaos in power system are found and deeply investigated. They are route of cascading period doubling, route of directly initial energizing and route of torus bifurcation (or quasi-periodicity). The latter two routes are investigated for the first time in power system stability studies; 3 When the stability conditions of chaos are broken, it is found they can lead to voltage collapse, angle divergence, or voltage collapse with angle divergence simultaneously.

针对在电力系统小扰动稳定区域内可能存在混沌吸引域的有关报道，本文深入研究了电力系统混沌现象的出现途径和与系统失稳模式之间的关系：1利用Li-Yorke定理和Li-Yorke的混沌定义，从理论上证明了电力系统混沌现象的存在性；2发现了电力系统中导致混沌出现的三种可能途径：倍周期分岔导致混沌、初始能量直接激发混沌和经由环面分岔导致混沌，并对后两种新发现的途径进行了较为细致的研究；3发现了混沌极限环破裂导致电压崩溃、角度失稳以及电压崩溃和角度失稳同时出现的现象，其中混沌极限环破裂导致系统角度失稳和电压崩溃及角度失稳同时出现的现象均属首次报道；4证明由微分-代数方程描述的系统模型，其小扰动稳定域的边界只包含HB、SNB和SIB三种分岔界面，在SSSR的内部和边界上，均不可能存在会导致混沌的点，从而将混沌现象排除在小扰动稳定域的研究之外，简化了后者的研究工作。

A new parameter is introduced here to measure the locality of particle distribution. The relationship between local coefficient and particle density is simulated with random updating rule and critical density is measured, which is in conformity with the critical density of the system.

我们引入了一个新的参量局域化系数来度量系统粒子分布的局域性，数值模拟了在随机动力学规则下的局域化系数随粒子密度的变化关系，得到临界密度，结果与解析得到的系统临界密度相符。

The laryngeal lymphatic system is characterized by regional differences in lymphatics density with the highest density in the larynx surface of epiglottis and lowest density in the vocal folds.

喉各分区淋巴管分布具有显著差异，其中以会厌喉面分布密度最高，声襞淋巴管的分布密度最低。

Step one: press Win + Pause / Break key combination to open "System Properties", switch to the "Advanced" tab, click the "Environment Variables" button, in which the "system variables" column, click on the "new" button in the "variable name" inside input "Devmgr_show_Nonpresent_Devices", in "Variable Value" enter "1", three "OK" after the withdrawal from the "System Properties" window

第一步：按下Win+Pause/Break组合键打开"系统属性"，切换到"高级"选项卡，点击"环境变量"按钮，在其中的"系统变量"栏中，点击"新建"按钮，在"变量名"里面输入" Devmgr_show_Nonpresent_Devices"，在"变量值"输入"1"，三次"确定"后退出"系统属性"窗口

At the same time it is know by analysis about matrix characteristic of the similar orthogonally that not only the characteristic value after the transformation is equal to the ones before the transformation and they are independence to time variable of the system, but also the eigenvectors of the formed system can showed the effect of the time variable on original system.

同时，根据矩阵正交相似的性质分析得知：不仅变换前后两个矩阵的特征值完全相同并与时间变量无关，而且时间变量对此系统的影响可以只由变换后系统的特征向量来描述，给出了非典型阻尼振动系统物理意义上的解释。

This paper introduces the operation principle and a travel fault accident of variable-speed DC drives system for the car puller of car dumper system in Jiangxi Fengcheng power plant,finds and analyses the potential reason,summarize it was caused by the wrong of PLC analog output module,and proposes some suggestion about variable-speed DC drives system maintenance.

简要介绍了丰城电厂翻车机系统拨车机直流调速系统工作原理及一次拨车机行走异常故障，对各种可能故障因素进行查找分析，归纳出由于PLC模拟量输出模块故障导致拨车机异常行走的结论，并对同类直流调速系统的维护工作提出了建议。

If mark the probability density function of continuous random variable X and continuous random variable leave each other, then when,there is , there is inverse function of .

Theorem 如果将连续型随机变量和连续型随机变量的概率密度函数分别记为，则时有：，这里是的反函数。

In this study, two models to fit soil three-variable characteristic surfaces of different soils were proposed based on the Brooks-Corey soil water retention curve model. Advantages, disadvantages and application conditions of the two were illuminated. In addition, soil three-variable surfaces measured for packed soil samples through centrifuging and controlling bulk density using paraffin material were used to verify the proposed models.

本文在Brooks-Corey土壤水分特征曲线模型的基础上，提出了两种描述土壤质量含水量、吸力和容重三变量关系的曲面模型，分析了模型的优缺点和适用条件，并采用离心机石蜡控容重法实测了四种质地填装土壤的三变量特征曲面。

The book is divided into 14 chapters, including Introduction, continuous control system theory, process and discrete sampling, Z transform, sampled-data systems, discrete approximation of continuous system the equivalent, based on mathematical transform the classical design method, based on state space pole placement design methodology, multi-variable system of quadratic optimal control, quantitative effects, the choice of sampling period, the digital control system modeling, digital control system for a variety of design methods, variables quadratic optimal control systems, sampling cycle of selection, non-linear control of the problem, as well as digital control system, a typical application - Disk drive servo control design.

全书共分14章，内容包括概论、连续控制系统理论、采样过程和离散化、Z变换、采样数据系统、连续系统的近似离散等效、基于数学变换的经典设计方法、基于状态空间的极点配置设计方法、多变量系统的二次型最优控制、量化效应、采样周期的选择、数字控制系统的建模问题、数字控制系统的各种设计方法、变量系统的二次型最优控制、采样周期的选择、非线性控制的有关问题，以及数字控制系统的一个典型应用——磁盘驱动器的伺服控制设计等。

The major findings include:(1) By using fuel as the base indicator of relative efficiency, we found the following input factors' distribution inefficiency for domestic airlines: The distribution inefficiency of labor and capital input factors differs from airline to airline, and is becoming more severe with time; the distribution inefficiency of other factors does not differ very much among airlines but varies with time. It is inefficient from 1989 to 1995 but becomes more efficient during 1996 to 1997;(2) Airline companies have higher economies of density before 1996, but tend to show a constant return to density in 1997 when considering allocative distortions. The technical efficiency of input factors as a whole has declined after the open-air policy;(3) The costs of airlines are increasing significantly due to their distribution inefficiencies;(4) The instrument variable generated through a quasi price function does not have significant influence on cost; this may imply that airline companies in this time period did not exhibit the phenomena of high-quality high-price.

其主要结论如下：(1)藉由相对燃油分配效率探讨各投入要素之分配扭曲情形发现：劳动和因定投入要素之分配无效率因公司别而有所不同，且随时间而严重，唯民国86年稍有改善；其他要素之分配无效率则较不因公司别而有所不同，但亦随时间发生变化，初期为无效率，在民国85、86年则较具效率；(2)若考虑分配扭曲情形下，国内航空业在民国85年之前具有较高之密度经济，民国86年则趋向固定密度报酬；此整体投入要素之技术效率而官，在天空开放政策后其技术效率随时间变化而下降，但就燃油投入要素平均技术进步率而言，则其技术效率逐年增加且幅度明显；(3)航空公司因分配无效率所造成成本增加的情形相当明显；(4)准价格工具变数对成本之影响并不明显，此可能反映在此期间国内航空公司似乎并未趋向於高品质高价格之现象。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。