极限关系

According to the change of the enemy\'s quantity and the qualitative theory of the differential equation, we research the spruce aphides and its predator system. At the same time, we discussion the spruce aphid multiplication model when the natural enemy quantity is a certain value and the periodic oscillating model whose the quantity of the natural enemy changes along with the time. Obtains the stability condition of the balance point and the limit-cycle existing condition, the system presents the dissipative structure\'s character. Finally it explains that this theoretical analysis has certain practical significance regarding the preventing and controlling harmful insect.

第五章，松毛虫与其天敌的关系是食饵和捕食者的关系，根据天敌数量的变化，利用微分方程定性理论，研究松毛虫与天敌系统，讨论天敌数量为一定时的松毛虫增殖模型和天敌数量随时间变化的周期振荡模型，得到正平衡点全局稳定性和极限环的存在条件，通过计算机模拟，说明周期振荡的捕食模型能够呈现典型的时间耗散结构特征，对于防治害虫有一定的实际意义。

The relationship between transient response and shape design variables is highly non-linear, and the behavior of feasible domains is often not good, which may cause convergence difficulties. In order to improve convergence speed of iteration process, some algorithms the feasible domains adjusting, the adaptive move limit, the approximate line search and the approximate reanalysis, are adopted.

采用基于Newmark积分的直接求导法计算瞬态响应灵敏度，在序列二次规划算法中采用了可行域调整、近似—维搜索、自适应运动极限等改进技术，提高求解效率和收敛稳定性，以解决结构动态响应与设计变量的关系复杂、高度非线性，优化可行区域的性态不良等问题。

Though comparing Canny operator and center B spline dyadic wavelet, the following conclusion is proven in this dissertation: a Center B spline function has tight support and Canny operator hasn't. b Center B spline function asymptotic convergence to Gaussian function and the derivative of Center B spline function asymptotic convergence to Canny operator. c The derivative of fourth order center spline B function is more suitable as a optimal edge detector than Canny operator. d Center B spline function can balance the smoothing and approximation of original data, and the fourth center B spline function is the only optimal solution of two order smoothing problem. e The error between the valve of time-frequency uncertainty of the fourth center B spline function and the lower bound of time-frequency uncertainty does not exceed 0.143% of the lower bound. f The derivative of center spline B function can construct a stability dyadic wavelet and can give a fast algorithm for multiscale edge detection, but Canny operator can do neither.

作者给出了Canny算子与中心B样条二进小波严格的比较证明，得出如下结论：a中心B样条函数具有紧支集，Canny算子不具有紧支集。b中心B样条函数的极限收敛于高斯函数，中心B样条函数的导数收敛于Canny算子。c四阶中心B样条函数的导数比Canny算子更接近最佳边缘检测滤波器。d中心B样条函数比高斯函数更能兼顾对原函数平滑和逼近的折中要求，并且四阶中心B样条函数是二阶逼近问题的唯一最优解。e四阶中心B样条函数的时频测不准关系值与时频测不准关系下界的逼近误差不超过0.143％。f中心B样条函数的导数可以构成稳定的二进小波，存在快速的多尺度算法；而Canny算子不构成稳定的二进小波，无法给出快速的多尺度算法。

It provided a correct and reasonable mathematical model for the analysis of the ultimate bearing capacity and crankle stability of the thin-walled structure.

论文在比较了两种运动描述方法（完全拉格朗日法和更新拉格朗日法）异同点并分析了非线性几何关系及大变形下的弹性物理关系的基础上，基于增量虚功原理推导了几何非线性空间梁元单元切线刚度矩阵，采取分模块形式，分别表示了轴力、弯矩、双力矩对几何矩阵的贡献；通过球面显式荷载增量迭代式弧长法求解方法编制程序，很好地实现了几何非线性增量荷载的自动步长选择及全过程跟踪，为薄壁杆系结构的极限承载力分析和弯扭失稳分析，提供了较为精确合理的分析力学模型。

Based on the analysis of the excitation spectrum, we obtain the superfluid-Mott-insulator phase transition condition, and superfluid velocity of ultracold dilute gas of bosonic atoms in an optical lattice, and point out that the velocity of superfluid can be experimentally adjusted by controlling the parameters of optical lattice.

在长波极限下，色散关系是线性的，这与无外场时的色散关系相同。从激发谱分析可得到superfluid-Mott绝缘相变条件，给出了光格子中超流速度，并指出在实验上可以通过控制光格子参数来改变超流速度。

So the calculational results of the formulas are emanative. Avoiding to use the empirical coelfficients are in the analytic process and based on the stress-strain relation between core concrete and steel tube the ultimate bearing capacity and the deformation characteristic of the steel-encased reinforced concrete columns are investigated in this paper. Then the reasonable stress-strain model is given for the further work of the damage analysis of steel-encased concrete and aseismatic ductility.

本文在分析过程中尽可能的避开经验公式，从核心混凝土与钢管的应力-应变关系入手，通过应力协调与应变相容的条件对配有圆钢管的钢骨混凝土构件的极限承载能力与变形性能进行研究，提出合理的应力-应变关系模型，为进一步的钢管混凝土结构损伤、抗震延性分析做好准备工作。

Better numerical prediction of the distributions of shear forces and bend moment within the pile group has also been obtained with the consideration of many stochastic parameters such as the soil properties of sea warf, seismic properties, etc. And then we analyze the dynamic nonlinear seismic pile-soil interaction in sea warf as an example to apply the software of ANSYS to the assessment of the dynamic interaction of soil-structure in the harsh situation of random earthquake. And then we denoted that the soil-pile interaction is too difficult to be expressed in equations because the non-linear interaction between soil and pile.

5桩基由于其本身的优点得以在海洋码头结构中大量的运用，但是海洋码头结构在海洋环境下受多方面的影响，土与桩体的相互作用关系很难清楚的表达，由于影响因素的多样性及复杂性，以及它们与桩基性状之间的非线性和非确定关系，使得关于桩基性状的各种理论解答还不能采用简便的表达式以反映其复杂多变的机理，尤其是难于反映施工及环境因素对桩基性状的影响，而且如何发挥桩基的技术经济效益和如何合理的确定桩的极限承载力，也是一个技术难度很大的问题。

Based on the unloading stress-strain relationship obtained from the unloading stress path experiment reflecting the stress-strain characters of soil in the active area behind the wall, the relationship between the friction angle and wall movement is established under nonlimit state.

根据反映墙后主动区土体应力-应变性状的卸荷应力路径试验确定的应力-应变关系，建立非极限状态摩擦角与墙体位移的关系。

A computer simulation based on strong-weak model shows good agreement with the linear theory. The linear theory of the ion trapping instability caused by ions in equilibrium is also introduced in this paper.

包括不稳定性的增长率与中性化系数的关系、阈值与中性化系数的关系、束流的相干频率漂移和展宽、离子在空间的分布和尺寸、离子动态丢失的机制以及离子在储存环内积累的极限。

Based on basic theory of elastic wave propagation, wave equation forpropagation of elastic wave in 2 dimension vertical inhomogeneous mediumof similar concrete cutoff wall model is developed. 2 dimension elastic sheetof concrete cutoff wall is established to research law and energy distributionrelations between propagation, attenuation, reflection and transmission ofelastic wave in concrete cutoff wall; Based on the concept of resolution, thecontent of vertical reflection method used to inspect concrete cutoff wallresolution is raised and factors will have influences on resolution are analyzed,expression of defective layer composite reflection factor and detectabledefective layer maximum thickness are developed; Relations between allsteps of sampling system of vertical reflection are build, the influence ofcentrum characteristics and receiving sensor on testing results are analyzed,therefore parameter requirements for testing instrument and parameter selection principle of collected parameters are raised.

2从弹性波传播的基本理论研究出发，推导了弹性波在类似混凝土防渗墙模型的二维垂向不均匀介质中传播的波动方程式；建立了混凝土防渗墙二维弹性薄板模型，研究弹性波在混凝土防渗墙中的传播、衰减、反射、透射规律及能量分配关系；从分辨率的概念出发，提出了垂直反射法检测混凝土防渗墙分辨率的内涵，对影响分辨率的因素进行了分析，推导出了缺陷层复合反射系数、可检测缺陷层极限厚度的表达式；建立了垂直反射法采样系统各环节之间的关系，研究分析了震源特性、接收传感器对测试结果的影响，提出了对测试仪器参数的要求及采集参数的选择原则。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。