比较函数

With the help of comparison theorem, sufficient conditions which guarantee permanence of the system are obtained. For the almost periodic case, by constructing a suitable Liapunov function, we obtained that the system has a unique globally asymptotically stable positive almost periodic solution. Finally, we study a multispecies predator-prey system with stage structure and Holling II type functional response.

第二部分考虑具有阶段结构的非自治扩散捕食系统，利用比较定理得到该系统持久生存的充分条件，其后在概周期情形下通过构造合适的Liapunov函数得到了保证该系统存在唯一一个全局渐近稳定的概周期解的条件。

The asymptoticbehavior of two ecological systems and the unconditionally stability and oscillations in kinds of 4-order delay difference equations are investigated by using analysis method, constructing Lyapunovfunctions, the logarithmic norm, charateristic roots theory and the bifurcation theory. Here, theasymptotic properity includes the uniform persistence, the global attractability of the solutions,the asymptotic stability of the positive solution local or global and the oscillations of solutions.

本文利用定性分析的方法、比较原理、特征值分析法、对数范数、构造Lyapunov函数及分支理论等方法和理论，研究了两类生态模型解的渐近性及一类四阶时滞微分方程解的无条件稳定性，其中包含模型的一致持久生存性、正平衡态的全局吸引性、局部和全局渐近性以及解的振动性等问题。

Experimental study on the properties of autocorrelation function of image speckles produced by weak random screens.

随机表面散射光场的格林函数法与基尔霍夫近似的比较。

In chapter 5, the design of oscillator is discussed. First introduced the condition of how to make circuit oscillate and keep stabilization. And compared the advantage and shortcoming of design oscillator with S parameter or Bessel Function method.

第五章主要是讨论了射频前端关键模块本振源振荡器的设计，分析了反馈振荡器的起振、平衡条件，比较了用晶体管S参数和时域贝塞尔函数法设计振荡器的优缺点，最后以科尔皮兹型振荡器为例用ADS软件进行设计仿真，给出了设计结果。

Instead of Gronwall\'s inequality,the non-linear Bihari inequality is crutial in dealing with the non-Lipschitz equations.Moreover,we emphasize that the dominating functions in non-Lipschitz conditions always satisfy concavity and some non-integrability near zero.The concavity is for using Jensen\'s inequality.Because of the non-integrability near zero,we can apply the comparison theorem of ordinary differential equations together with Bihari\'s inequality to yield many results.

3作为Gronwall不等式的推广，Bihari不等式在处理具有非Lipschitz系数的方程时不可或缺；同时应当注意，非Lipschitz条件中所涉及的控制函数总是满足凹性和某种零点处的不可积性：凹性是为了利用Jensen不等式；零点处的不可积性使得Bihari不等式与常微分方程中的比较定理结合在一起从而完成很多结论的证明。

Compared with test results, the rationality of the proposed bilinear principal stress function is testified.

通过与试验数据的比较，表明所提双线性主应力函数的合理性。

Finally, the dispersive characteristics are analyzed to demonstrate the efficiency of real variable Compact 2D FDTD method and Blackman Window Function.

通过微带色散特性的分析，表明用实变量Compact 2D FDTD法与Bhckman窗函数，只需要较少的迭代就可以得到比较好的结果。

A comparison is made between the performance of harmonic analysis method and that of Blackman window method through the simulated experiments, and in the condition of same order of filters, the stop-band attenuation of filters designed by this method is 5~7 dB more than that of filters designed with Blackman window in the range of different frequencies.

通过仿真实验，把其结果与用Blackman窗函数设计的滤波器的性能进行了比较，在滤波器阶数相同的条件下，在不同频率范围内，该方法比用Blackman窗设计的滤波器的阻带衰减大5~7dB以上，不仅过渡带宽依然变小，而且二者的通带波纹大小相差很小。

Through a construction of a distribution function,the normal form of KFVS is deduced based on the nocollision Boltzmann equation .

通过构造一个分布函数，利用无碰撞的 Boltzmann方程，推导出求解一般形式的KFVS方法，对一维溃坝进行了模拟，并与精确解进行了比较，说明了这种方法的进步性和可行性

The simulation results show that the performance of the boxcar window is the best, while the worst is triangular window.

比较了窗函数对逆幂律特性的影响，仿真表明矩形窗的效果最好，三角窗最差，汉宁窗居中。

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。