Riemann-Liouville分数阶非线性系统的稳定性分析

通过讨论Riemann-Liouville分数阶非线性系统的稳定性,特别地分析了扰动系统的稳定性。基于分数阶线性微分方程的稳定性理论,利用拉普拉斯变换、Mittag-Leffler 函数和Gronwall不等式,给出了一些稳定性定理。     

对“生态系统抵抗力稳定性和恢复力稳定性”的辨析

生态系统的稳定性不仅与生态系统的结构、功能和进化特征有关,而且与外界干扰的强度和特征有关,是一个比较复杂的概念,不能片面地认为抵抗力稳定性与恢复力稳定性之间存在相反的关系.     

稳定性的几何描述

由相平面的奇点理论，得到了判别力学系统稳定性的几何表示-稳定域，它与KTC定理，首次近似特征方程相比，能够较全面地、形象地、直观地表述系统的稳定性。     

汽车操纵稳定性控制系统的分析

汽车操纵稳定性的研究,是与汽车车速的不断提高分不开的.早期的低速汽车,还谈不上操纵稳定性问题,最早提出操纵稳定性问题,是在具有较高车速的赛车上.后来,随着车速的不断提高,在轿车、大客车和载货汽车上也都不同程度地出现了类似的问题.因此汽车操纵稳定性的研究成为当今研究热点.本文从国内外汽车操纵稳定性控制的研究现状出发,对汽车操纵稳定性进行仿真分析.     

生态系统的抵抗力和恢复力稳定性

生态系统抵抗力稳定性和恢复力稳定性之间不能简单地理解为呈负相关关系。在比较生态系统中这两种稳定性大小的时候要遵循相对性、程度性判定和不可同时性原则。抵抗力稳定性与生态系统营养结构的复杂程度和物种丰富度呈正相关;恢复力稳定性的大小可以通过比较其恢复原状所花时间的长短来判定,但这必须依靠实际的测量数据来支持。     

灰色离散系统的稳定性分析

要分析一个控制系统的动、静态特性,首先要判断系统是否稳定.利用特殊矩阵分析方法与技巧讨论线性灰色离散系统的稳定性,对应地给出非线性灰色离散系统的稳定性问题的充分条件.     

长江口泥沙沉降的光扫描研究

本文利用光扫描方法测定细颗粒泥沙的沉降速度来研究长江口区泥沙的稳定性,得出与前人研究的絮凝动力学沉降二级反应机理不同的结论。我们的研究为泥沙沉降动力学一级反应机理。同时,还比较详细地研究了PH值、有机物等对泥沙沉降稳定性的影响:泥沙的稳定性随PH值增大而增大;有机质的存在使体系稳性增强;电解质浓度增大使体系中泥沙稳定性减弱;污水的加入也使泥沙稳定性增。并且还用D·L·V·O理论及双电层理论定性地解释了实验结果。     

初中生学绩稳定性与自我概念的关系探讨——以安徽省某中学为例

本文采用问卷调查法,考察初中生的学业成绩及学绩稳定性对自我概念的影响。调查结果显示：学生的一般自我价值感、理科自我概念、艺术自我概念、学业自我与其学绩稳定性相关显著;学业成绩越稳定的学生,其理科自我概念和家庭自我概念越积极,高学绩稳定性学生的艺术自我概念显著低于低学绩稳定性学生;学习表现优秀的学生,对一般自我价值感、人际自我概念、道德自我概念、学业自我概念、家庭自我概念、理科自我概念、诚实性自我概念的感受也更加良好。这表明,初中生在学习上的表现及其学绩的稳定性,选择性地影响了自我概念的形成。     

切削稳定域影响因素分析研究

通过利用Altintas再生型切削颤振预测理论,建立了切削稳定性预测模型,对切削稳定域影响因素解析,系统性地得到对机床稳定域的影响规律。通过锤击模态试验和切削试验将稳定性预测相关参数得出。利用单因素法分别讨论了模态刚度、固有频率、阻尼比、切削系数四大主要参数对切削稳定性的影响。利用相关软件绘制得到系统稳定域图形,并对相关计算结果进行分析总结,为后续优化切削加工工艺,提高切削稳定性及生产效率等工作提供指导依据。     

在手球模拟训练中提高学生的心理素质

手球运动是一项具有高度时间性、对抗性、协同性、针对性、紧张性、适应性等特点的运动竞赛项目.一个优秀的手球学生需要自信心、意志力、应变力等良好的心理品质,而心理稳定性和适应能力又是其中的关键和基础.学生的心理训练是有目的、有意识地培养学生在紧张的比赛中保持心理稳定性,心理稳定性是其中最基础的素质之一,只有心理上的稳定,才能带来技术上的稳定和正常发挥.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.