查询词典 continuous dynamical 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。

Factory remaining hot water, remaining vapor and boiler heating system, were adopted in tilapia overwintering. Every step, such as site selection, pond and fish preparation, cultivation of fish, fish selection, timing of overwintering, stocking density and managements during overwintering, was compared among three systems. The results of data analysis showed that the survival rate in remaining hot water system was 12% higher than in remaining vapor system and 21.25% higher than in boiler heating system. The overwintering cost in remaining hot water system was 735 Yuan/m~3, which was 18 Yuan lower than in remaining vapor system and 71.4 Yuan lower than in boiler heating system. The profit in remaining hot water system was 201 Yuan/m~3, which was 162 Yuan higher than in remaining vapor system and 275.4 Yuan higher than in boiler heating system.

本论文采取了余热水、余热气、锅炉加温三种方式对进行罗非鱼越冬保种，从地点选择、越冬池、鱼的准备、越冬苗种的培育、越冬前催肥、越冬鱼的选留、越冬鱼进池时间和密度、越冬期间饲养管理等环节进行对比试验获得了三种方式的试验数据并进行了分析讨论，结果显示：余热水越冬雌亲鱼的成活率比余热气越冬高出12％、比锅炉加温越冬高出21.25％；余热水越冬雌亲鱼的成本每立方米为735元比余热气越冬的成本每立方米低18元、比锅炉加温越冬的成本每立方米低71.4元；余热水越冬雌亲鱼的利润每立方米为201元比余热气越冬的利润每立方米高162元、比锅炉加温越冬的利润每立方米高275.4元。

The basic idea is to set a continuous solution of the region with a finite number of discrete points instead of a grid consisting of, these discrete points called grid nodes the solution of a continuous area on a given function of continuous variables used in the definition of discrete grid variable function approximation the original equation and boundary conditions in the micro-business operators to approximate differential, integral with the points and to approximate, so the original differential equations and boundary conditions are replaced by algebraic equations near Side, that is, finite difference equations , solve this equation group can get the original problem in discrete points on the approximate solution.

基本思想是把连续的定解区域用有限个离散点构成的网格来代替，这些离散点称作网格的节点；把连续定解区域上的连续变量的函数用在网格上定义的离散变量函数来近似；把原方程和定解条件中的微商用差商来近似，积分用积分和来近似，于是原微分方程和定解条件就近似地代之以代数方程组，即有限差分方程组，解此方程组就可以得到原问题在离散点上的近似解。

With the increase of continuous cropping year, ammonifying bacteria, azotobacter and cellulolytic bacteria showed the tread of first increases and then decreases and reached the biggest value at continuous cropping for 5 and 3 yr, while the nitrifying bacteria quantity was decreased sharply with the increase of continuous cropping year.

随连作年限的增加，氨化细菌、固氮菌和纤维素分解菌数量呈现先增加后降低的趋势，分别在连作5、3和3年达到最大值，而硝化细菌数量随连作年限的增加急剧下降。

From [1], Every transition function is a positive strongly continuous semigroup of contractions on l\, but it isnt a strongly continuous semigroup on l_∞- In fact, the sufficient and necessary condition for a transition function to be a strongly continuous semigroup on l_∞ is that the q—matrix Q is an uniformly bounded q—matrix on l_∞- This is the trivial case.

由Anderson[1]知道转移函数P是l_1空间上正的强连续压缩半群，但P一般来说不是l_∞空间上的强连续半群，而P是l_∞上强连续半群的充要条件是q—矩阵Q是l_∞。

Synopsis: To penetrate the continuous development of environment and population during the art teaching, art teachers should not only study thoroughly and tap fully the visible combination point of the EPD education in the teaching material, but also pay close attention to the recessive catenation point of the positive emotion in order to make the students practice the cooperation and innovation, feel the beauty, so as to merge the art teaching and the educational ideology continuous development, then to accelerate the students' all-around, healthy, harmonious and continuous developing.

内容提要：在美术教学活动中渗透环境的可持续发展与人口的可持续发展教育，美术教师不仅要深入研究、充分挖掘教材中EPD教育有形的"结合点"，而且要紧抓积极的情感体验这个隐性的"链接点"，让学生体验合作、体验美、体验创新，使美术教学与可持续发展教育浑然一体、情景交融，进而促进学生全面、健康、和谐、持续发展。

We introduce the notion of fuzzy-valued continuous function on a compact set K in a metric space, and discuss its properties; On this base, we study the uniformly d∞-convergence of a sequence of fuzzy-valued continuous function on K. We prove that the space of fuzzy-valued continuous functions on K, i.e. C(K, E1), is a complete metric space with respect to the metric D.

引入了定义在某度量空间的紧子集K上的模糊数值连续函数和水平连续函数的概念，讨论了它们的某些性质；在此基础上，研究了K上模糊数值连续函数列的一致d∞-收敛性，证明了K上模糊数值连续函数空间C(K， E1)关于度量 D 构成一个完备的度量空间。

If is continuous at ,, and is continuous at , then the composite function is also continuous at .

若函数在连续，且，而函数在连续，则复合函数在也连续。

The identity and difference in the expressional patterns between distribution functions of discrete random variables and distribution functions of continuous random variables are elaborated,and the main expressional patterns of distribution functions of continuous random variables are summarized,and the derivability of distribution functions of continuous random variables is discussed.

0引言在概率论中，连续型随机变量分布函数的表达形式及其可导性是一难点。其一，离散型随机变量的分布函数有较明显的性质和统一的表达形式，而连续型随机变量，由于其概率密度函数一般为分段函数，根据其分段区间的差异，表达形式差异较大，不容易总结其规律，本文主要比较连续型随机

Studies showed that there were two typical combinations of the facies in the filling sedimentary sequence of the epicontinental basin, wherein one was the depositional diastem developed between the facies, which was a discontinuous combination of the depositional facies with continuous time sequence, namely the exposed sediments, the tidal flat swamp and the peat swamp, and the shallow marine sediments appeared from bottom to top; and the other was the continuous sequence with gradually evolved sedimentary environment, in which it was a continuous process that the tidal flat swamp turned gradually into the peat swamp.

研究表明：陆表海盆地充填沉积序列中有两种较为典型的相组合，一是相与相间发育沉积间断面，为不连续沉积相组合，但在时间序列上是连续的，即自下而上依次为暴露沉积、潮坪沼泽及泥炭沼泽、浅海沉积；第二种序列是连续相序，盆地的环境演化是渐变的，潮坪沼泽化逐渐泥炭沼泽化是一个连续过程。

I'm not an actor. I'm a professor of paleontology.

我不是演员，我是古生物学教授

Spider Network Web site that is a very image of the name.

网络蜘蛛即Web Spider，是一个非常形象的名字。