稳定性

In this dissertation, periodic impact motions in vibro-impact systems are studied, and the existence and stability of superharmonic periodic impact motions are obtained. The critical bifurcation parameter intervals of superharmonic periodic impact motions are deduced, and numerical simulations are used to verify the results.

中文题名碰振或约束系统的全局分析及稳定性研究副题名外文题名 Studies on global analysis and stability in vibro-impact or constraint systems 论文作者张彦梅导师陆启韶教授学科专业一般力学与力学基础研究领域\研究方向学位级别博士学位授予单位北京航空航天大学学位授予日期2002 论文页码总数95页关键词碰振系统转子系统多体系统碰撞振动馆藏号BSLW /2003 /O322 /1 本论文讨论了碰撞振动系统的周期碰撞运动，得到了超谐周期碰撞运动的存在性和稳定性，推导出亚谐周期运动的临界分岔参数区间，并利用数值模拟进行验证。

Using orthogonal test design to optimal the surface activator components and its ratio, analysis each factors on the effect of the suspensibility, hierarchical rate, disparity, centrifugal stability, then determined the major technical index's: NNO has the most important influence on suspensibility, NNO on hierarchical rate, XG on disparity and XG on centrifugal stability.

本试验从10种润湿分散剂中筛选出农乳601#、md、ms及其用量，利用正交试验设计对表面活性剂组分及其配比进行了优化，分析了各个因素对悬浮率、分层率、分散性、离心稳定性的影响，并确定了制剂的主要技术指标：NNO对悬浮率的影响对大，NNO对分层率的影响最大，XG对分散性的影响最大，XG对离心稳定性的影响最大。

Anaerobic synecology of the hydrogen-producing fermentation system was investigated under certain test condition in this thesis. In the continuous flow system of anaerobic hydrogen-producing fermentation, the succession of hydrogen-producing acidogenic microbiology may be regressive process. By regressive process we means that the original community getting from nature which structure being complex with a high ability would degenerate gently to a certain climax community which structure being simple with less ability.

产氢发酵系统的微生物群落生态学研究证明，在连续流发酵产氢反应系统中产氢产酸发酵细菌群落的演替过程，是在人为控制的生境条件下，微生物从自然群落这种稳定性大、组成及生化反应过程复杂的生态群落，向稳定性小、组成和生化反应过程相对简单的某一产酸发酵顶极群落进行的"逆行演替"。

Then, it studies the supply chain management system as a complex system to confirm the state existing during operating of the system. After that, it conducts a probability analysis on the state which the system located by applying supplement variable method, and establishes the model of distributed parameter system in a form of partial differential equations. Combining C0 ? semigroup theory in the functional analysis, it conducts a dynamic analysis on the established mathematical model. Using this method, it obtains the mathematical expression of the dynamic solution and the steady state solution, and proves the uniqueness, non-negativity and the asymptotic stability of the system solution. This dissertation applies the Matlab tool and uses two-step, three-step Simpson integral equation to imitate the condition of system solution. Then, it adds possible mode of failure and the optimization adjustment state to the system, based on which it has established the distributed parameter system model which is described by partial differential system of equations. Combining the functional analysis C0 ? semigroup theory, it studies the established mathematical model, and obtains the mathematical expression of the dynamic solution system and the steady state solution. It has proven the existing of uniqueness of the system solution, the asymptotic stability of system solution and the system solution. In addition, it has lying the theory rationale for further analysis and the research on the optimization of system.

本文首先简要综述了供应链理论、可靠性研究、鲁棒性研究以及供应链鲁棒性研究的现状；然后，将供应链系统作为一个复杂系统来分析，确定了系统运行过程中所经历的状态，通过引入补充变量的方法，建立了用偏微分方程组描述的分布参数系统模型，用泛函分析中的C_0 -半群理论得到了系统动态解和稳态解的数学表达式，证明了系统解存在的唯一性、非负性和指数阶渐近稳定性；并借助Matlab工具，利用二阶、三阶辛普森积分方程模拟系统解的性态，并给出系统动态解的仿真图；本文又对上述系统增加了系统可能失效状态和优化调整状态，并在此基础上建立了用偏微分方程组描述的分布参数系统模型，同样用泛函分析中的C_0 -半群理论对所建立的数学模型进行了研究，得到系统动态解和稳态解的数学表达式，证明了系统动态解存在的唯一性、非负性及渐近稳定性，为进一步分析和研究供应链优化奠定了理论基础。

In order to improve the hydrothermal stability of leather,two kinds of tanning agents with weak properties were used in combination tannage .

利用两种鞣性比较弱的鞣质进行结合鞣制，得到的成革的耐湿热稳定性大幅度提高，原因是在这两种鞣质之间形成了协同效应，即Synergistic Effect，这是提高成革稳定性的一个比较新型的研究理论体系。

The DFT (B3LYP/6-31 + G) method was used to study the relative stabilities and probable proton transfer in isolated and monohydrated 2,4-dithiothymine molecules in gas phase. The effects of water on relative stabilities and the rate of the proton transfer were analysed. The results indicate that only one tautomer for 2,4-dithiothymine can exist in gas phase.

采用密度泛函方法在B3LYP/6-31+G水平上研究了2，4-二硫基胸腺嘧啶孤立分子和水合物的异构体的相对稳定性和可能的质子迁移反应，分析了水分子的参与对 2，4-二硫基胸腺嘧啶异构体的相对稳定性和质子迁移速率的影响。

This paper studies the stability of the system =f, some simple criterion for stability is proved using the methods of global linearization and tensor space analysis.

本文首先将非线性系统全局线性化，然后在张量空间中分析了其稳定性态，给出了原系统简洁的稳定性判据。

The evenness degree, stability, and uniformity of the nano-SiO2/ acrylic resin latex were all better than congener latex without SiO2, the density and thermolysis stability of the film were improved as well.

结果表明，引入原位形成SiO2的乳液体系，各组分的均匀度及稳定性均很好，尤其可提高复合涂层的热稳定性和抗回粘性，可望在耐水包装领域得到广泛的应用。

This alignment material provided good thermostability and was stable under weak UV irradiation as well.

这种取向膜材料同时具有很好的热稳定性及抗紫外稳定性。

Structural comparison has revealed insights into the molecular basis of the differential thermostability of D-hydantoinases.

不同来源的D—乙内酰脲酶的热稳定性不同，三维结构的比较为热稳定性的变化提供了理论依据。

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。