系统发生

This paper reviews recent advances in myriapod phylogenetics and presents a preliminary phylochronologic scheme of the evolutionary events in early my-riapods with the following observations: 1） Myriapoda might have diverged from its sister group during late Cambrian or earlier.

精确的多足动物亚门谱系发生关系以及谱系年代学细节还有待于进一步综合系统学、多基因和多重化石参照点的合理分析加以深入和完善，进而为早期陆地复杂生态系统的建立提供新的证据。

The possibility that stellar evolution of either Sirius A or Sirius B could be responsible for this discrepancy is rejected by astronomers on the grounds that the timescale of thousands of years is too short and that there is no sign of the nebulosity in the system that would be expected had such a change taken place.

恒星演化的可能性要么是天狼星A要么是天狼星B造成的差异，地球上科学家不认可这种看法，数千年的时间刻度太短，在系统内没有星云状物的迹象，在这系统内认为这可能性会发生的。

In a very long incubation period, although no infection symptoms, appearance as an ordinary person, but the body's immune system by HIV continues to damage to the immune system can no longer maintain the minimum defense capability, a variety of normal People will not cause the disease so that patients will be pathogenic microorganisms in the conditions of the infection, caused brain, lungs, gastrointestinal tract and other parts of the disease and symptoms.

在很长的潜伏期中，感染者虽然没有自觉症状，外表一如常人，但全身免疫系统仍在继续受到艾滋病病毒的破坏，到免疫系统功能再也不能维持最低的防御能力时，多种对正常人不会引起疾病的病原微生物便会使患者发生条件性感染，引起脑、肺、胃肠道和其他部位的病变及症状。

In a very long incubation period, infected Although there is no subjective symptoms, appearance, as ordinary people, but systemic immune system by the AIDS virus continues to damage to the immune system can no longer maintain the minimum defense capability, a variety of normal will not cause disease pathogenic microorganisms would make the conditions of patients with infection caused brain, lungs, gastrointestinal tract and other parts of the lesions and symptoms.

在很长的潜伏期中，感染者虽然没有自觉症状，外表一如常人，但全身免疫系统仍在继续受到艾滋病病毒的破坏，到免疫系统功能再也不能维持最低的防御能力时，多种对正常人不会引起疾病的病原微生物便会使患者发生条件性感染，引起脑、肺、胃肠道和其他部位的病变及症状。

It is found that the change of the frequency characteristics of chaotic system occurs mainly at the frequency band of the chaotic system, in which the input signal exists. The amplitude of the input signal doesn't influence the distortion of the output signal when masking signal is extracted by Oppenheim's chaotic masking.

研究发现，混沌系统频率特性的变化主要发生在输入信号的频率位於混沌系统频带内的情况下；输入信号幅度的大小，不影响输出信号的失真。

There are a lot of harmonic sources in power systems. It may cause series resonance and parallel resonance between inductive elements and capacitive elements of the power systems.

在电力系统中存在大量的谐波源，使得电力系统网络中感性元件与容性元件之间可能发生串联谐振或者是并联谐振。

Simulation results show that the chaotic system can be controlled effectively in Buck power converter by this method. The method is still effective when there are parameter perturbation and noise.

数值仿真结果表明：该方法能有效地实现Buck功率变换器混沌系统的控制，系统在参数发生摄动和存在噪声的情况下，控制仍然有效。

This paper shall attempt to look at some aspects of controller synthesis for the multivariable servomechanism problem when the plant to be controlled is subject to uncertainty-in this case,a controller is to be found so that satisfactory regulation/tracking occurs in spite of the fact that the parameters of the plant may be allowed to vary,subject only to the condition that the resultant perturbed system remains stable.

例7 本篇将致力于探讨在待检对象受到不确定性的影响，而仅仅服从受扰动的系统最终保持稳定，这一条件之情况下的多变量随动系统中控制器综合的某些方面的问题。在这种场合，尽管受控对象的参数允许发生变化，而控制器必须具有令人满意的调节和跟随性能。

In the study of the nonlinear dynamics, Melnikov function is widely used as a criterion to check whether subharmonic or ultra-subharmonic bifurcation even chaos will occur in a perturbed Hamilton system.

在非线性动力系统的研究中， Melnikov函数被广泛地用来作为微扰哈密顿系统是否发生次谐或超次谐分岔乃至混沌的判据。

First, for state estimation problem of the linear stochastic systems with uncertainties in both the state matrix and the noise matrix, a new satisfactory estimator is constructed with stochastic theory, which can guarantee that estimator error system with bounded perturbed model parameter satisfies the constraint indexes that is given. Thus a sufficient condition of solving satisfactory estimation is obtained; secondly, the algorithm of designing satisfactory estimator is presented by analysis.

首先，根据满意控制思想，针对一类在状态矩阵及噪声矩阵中均含有不确定性的随机系统，设计一种满意估计器，使预测误差系统在模型的参数发生扰动时，依然满足预先给定的设计约束指标，得到了满意估计问题求解的充分条件；然后根据分析给出了满意估计器设计的算法。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。