函数的最小

Then the effect of different target extraction algorithms on grating lobes was discussed in detail, a modified method based on 'abnegation method' was developed, which can achieve the optimal result in case of high sampling , simulation results prove that it is feasible.

对舍弃法进行了改进，改进后的舍弃法对自相关函数栅瓣较小的线性调频步进信号在采样率足够高的情况下，可以达到最优的处理结果，仿真结果证明了理论分析的正确性。

Regarding small convergence interval of conical degree as machinery sealed ring basic principle of structure optimization,with the maximum contact pressure as goal function,with the wear allowance of float ring as designing variable,the first order optimization method was applied to carry on thermal-structural coupling finite element optimization analysis of machinery sealed ring.

以小锥度的收敛间隙为优化原则，以最大接触压力作为目标函数，以静环端面的磨损裕度为设计变量，采用一阶优化法进行机械密封环热-结构耦合有限元优化计算。

At the early iteratives, the mutation rate is bigger and the aim is to make particles to explore smaller and isolate region and to avoid the algorithm trapping to the local optimum. While the algorithm runs, the mutation rate will be decreased to reduce the disturbing to the particles. IPSO adopts a new method that congregates some neighboring individuals to form multiple sub-populations in order to lead particles to explore new search space. Additionally, our algorithm incorporates a mechanism with a simple and easy penalty function based on the largest distance between the particle and the boundary of the feasible region to handle constraint.

IPSO采用了一种新型的变异策略，变异概率随着算法的运行是动态变化的：在算法运行初期，变异概率大，其目的是使算法不但能够探测到目标空间中的孤立区域，而且避免搜索陷入局部极值；在算法运行后期，变异概率逐渐变小，以减少对粒子的扰动；算法通过将部分具有邻近距离的粒子聚集成核形成多子群引导种群中粒子的飞行；采用一个简单的基于粒子与可行域边界最远距离的罚函数处理约束的机制，使得算法高效实现。

The result shows that the relationship between stress and strain can be described by Hardin model.

试验结果表明：该尾矿砂的动应力应变关系可用Hardin等效黏弹性模型描述，模型中的起始动剪切模量和最大动剪应力皆随固结应力比和有效固结围压的增大而增大，这两个参数与有效固结轴压成幂函数关系，且其受固结应力的影响较小。

In order to cancel the noise in TDR signal and retain the faint reflectometry signal made by deformation of rock and soil, it is proposed to use method integrated filtering and noise canceling based on wavelet transform with characteristic of TDR signal.

为去除TDR法岩土体变形监测信号中因多种原因而产生的噪声，同时最大限度地保留岩土体因变形而导致的微弱反射信号，提出结合小波函数和TDR监测信号特点的滤波与去噪方法。

The summary of the adopted models contains a two-scale k-ε turbulence model,the scalar joint probability density functiontransport equation approach,the augmented reduced mechanismfor methane oxidation (consisting of 16 species and 12 lumped reaction steps),the Euclidean minimum spanning treesmall scale mixing model etc.

所采用的数学物理模型包括双尺度的k-ε湍流模型，标量联合的概率密度函数输运方程方法，甲烷氧化的ARM简化化学反应机理(包含16种组分，12步总包反应)和欧几里德最小生成树小尺度混合模型。

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

This paper discusses the yield function, loading unloading criterion and constitutive equation of Lagrangian finite deformation elastic-plasticity theory. Finally, Lagrangian finite elastic plasticity theory is used on constitutive models of elastic-plasticity at infinitesimal strain, and the complete constitutive relation for singular yield surface theory is obtained.

本文讨论了Lagrange型有限变形弹塑性本构理论的屈服函数、加卸载准则、本构方程等，最终将Lagrange型有限变形弹塑性本构理论应用于小变形情况下的奇异屈服面弹塑性模型，得出了完整的Lagrange型有限变形弹塑性本构理论。

The results showed:①the communities that stipa baicalensis is edificator had the highest species diversity, and the idea that stipa baicalensis communities were the local zone vegetation was supported;②the majority of studied communities were unsaturated in the species diversity, and the species diversity had a tendency to increate with the improvement of soil environment;③the relation of species diversity to community productivity was a one-humped function, that is, the species diversity of mediation productivity was highest;④the species diversity under intermediate disturbance was highest, and the intermediate disturbance hypothesis was supported;⑤the content of potassium in soil had probably an important function, or was an important following factor in the types of grassland community;⑥a new hypothesis on the forming mechanism of species diversity of community, Small Scale Competition and Random-Patch Dynamic Hypothesis, was put forward boldly.

通过上述研究分析得出如下结果：①以贝加尔针茅为建群种的群落物种多样性最高，从物种多样性角度证明该群落类型最适应本区气候和环境条件，应是本区的地带性群落；②绝大多数群落的物种多样性处于未饱和状态，随土壤环境的改善呈明显的增加趋势；③物种多样性与群落生产力呈单峰函数关系，即在中等生产力水平时物种多样性最高；④放牧中等干扰水平物种多样性最高，支持Connell的中度干扰学说；⑤偶然发现土壤钾含量可能在草地植被类型分化中起到重要作用，至少是一个重要的伴随因子；⑥大胆提出了群落物种多样性构成机制的新学说即小尺度竞争随机斑块动态学说。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。