准周期的

The thermopower of decagonal AlCuCo quasicrystal was measured in the periodic and quasiperiodic direction by laser heating alternating current measurement method in the temperature range of from 300 K to 1200 K.

采用激光交流加热的方法测量了D相AlCuCo准晶周期与准周期两个方向的热电势，温度测量区间为300—1200 K。

It is clearly shown that the Al-Ni-Rh decagonal quasicrystal with 1.6 nm periodicity contains a kind of atom columnar cluster with about 1.6 nm periodicity as the most fundamental structural building block.

主要的研究结果可以总结如下：1利用高分辨电子显微技术在Al_(75)Ni_(15)Rh_(10)合金中发现了1.6 nm周期的十次准晶，报道了这种准晶在二次轴方向及在十次轴方向的高分辨结构，阐述了其周期及其准周期的排列方式。

Icosehedral quasicrystal, showing icosahedral point group symmetry and quasi-periodic order along three directions, has been intensively studied.

二十面体准晶是目前研究最广泛的准晶之，它具有二十面体点群对称性，属于三维准晶，就是说其原子在三维上都是准周期分布的。

We calculated the main effective second order nonlinear optical coefficients of the 〓 quasperiodic superlattice, analyzed the relationship between them and the quasi-periodic structure parameters, studied the extinction phenomenon and the extinction rules in quasi-periodic structure, standardized the expression of frequency conversion in homogenous crystal, periodic and quasi periodic superlattice crystal.

计算了〓准周期超晶格的有效二阶非线性系数，研究了它与准周期各结构参数之间的关系，分析了准周期结构中的消光规律，统一了频率转移效应在均匀材料、周期超晶格和准周期超晶格中的表述。

A fire\|new theory for periodic or quasi\|periodic signal sampling is proposed,w hich is especially for sampling high\|frequency wideband periodic or quasi\|peri odic signal by low sampling rate system.

涉及一种周期或准周期信号的采样技术，特别适用于低频采样系统采集高频宽带周期或准周期信号。

The theory of accretion disks are important for many astrophysical phenomena, including Quasars, active galatic nucleic, X-ray binary stars, and young stellar objects. The most important branch of accretion djsk theory is the stability properties of djsks. It is widely considered that the luminosity variations of various astronomical objects are associated with the instability of accretion disk. The viscosity plays an important role in the accretion disk theory, and magnetic field exists commonly in astronomical phenomena. A more realistic analysis of the stabihty of the accretion disk should include both the radjal and azimuthal perturbations because of the strong shear of viscous flow.In this paper, according to the luminosity Variations of Various astronomical objects, we study the radial-azimuthal instability of an isothermal with magnetic field. We find that the radial and azimuthal fields B〓,B〓 are mainly responsible for enhancing the instability of the magneto-acoustic modes and non-axisymmetric modes,and that pulsational oscillations are larger in the radial than in the Z direction. The model may be useful in explaining the periodic light variation of FU orionis and. T Tauri stars.

在许多天体物理现象中，例如活动星系核，X-射线双星和年青的恒星理论中，吸积盘理论起着重要的作用，而吸积盘理论中的一个重要分支是吸积盘的不稳定性理论，普遍认为活动天体的周期，准周期光变现象与吸积盘的不稳定性有关，在吸积盘理论中，粘滞起着重要的作用，而磁场是天体物理中普遍存在的现象，对于几何薄吸积盘不稳定性分析，由于强剪切流的缘故，应该包括径向和环向扰动两个方面，本文结合天体物理中的各种周期，准周期光变现象，研究了含磁场的等温薄吸积盘的径向-环向振荡不稳定性，结果表明：磁场的径向和环向分量对磁声模和非轴对称模的不稳定性的增加起着主要的作用，且径向振荡大于轴向振荡，所得结果有利于解释FU Orionis和T Tauri Stars的周期光变现象。

It means that earthquakes recur clusteringly in time intervals of close length. This model contains two kinds of meanings: one is that earthquake cluster quasi-periodically recurs, and the other is that earthquakes within an earthquake cluster clusteringly recur.

这种所谓准周期丛集复发是指大陆板内地震以大致相近的时间间隔成群丛集发生，它包含有两层含义：一是指地震丛是准周期重复发生的；二是指在某一地震丛内，地震又是丛集复发的。

During this period, variance contribution rate of quasi 100 ka cycle is up to 37.44%, and quasi 100 ka cycle has a leading role.

P。也发现地球轨道三要素中的偏心率准100 ka周期2、1 ka岁差周期及55 ka、8.3 ka、3.5 ka非轨道准周期，偏心率准100 ka周期具有主导地位（方差贡献率达37.44%）；3尽管黄土记录的东亚夏季风100 ka周期的产生机制已有多种假说，古气候学界还是普遍认为它产生于某些尚不清楚的过程，有待进一步研究。

On the other hand, data analysis reveals that the ionosphere and its background thermosphere undergo numerous kinds of variations, i.e. the diurnal, day-to-day, semiannual and annual variations.

在另外一方面，大量的研究工作表明，在电离层及其背景大气中广泛存在着各种时间尺度的变化行为，例如典型的周日变化、逐日变化、准27天变化、半年变化、周年变化、准两年变化以及随太阳活动周期的11年、甚至更长周期的变化等等。

Based on the return map and the principle of closed vectors, a new method is proposed to extract unstable periodic orbits embedded in chaotic attractors. As examples, the UPOs embedded in chaotic attractors of Logistic, Hénon and Lorenz are extracted respectively by this method. And our results of Skewed Hénon map also be compared with Nusse's. These results suggest that this method is valid for unstable periodic orbits from period one to period infinite of arbitrary dimension chaotic system. The dynamic considerations of spiking and UPO coding for individual neuron and neural system under external periodic and chaotic exciting stimulus also be studied in this dissertation. A lot of spiking phenomena, such as synchronization, period, and chaos appear alternatively with the changing of the stimulus frequency. For the small stimulus frequency the neuron could completely convey the periodic signal in synchronous anti-phase into interspike intervals sequences. For the slow time–scale chaotic input, the output two ISI sequences are reciprocally related to input signals, and their oscillation wave shape in time course can be derived from that of the input signals variation, furthermore, the similar input sequence and order of UPOs, distribution of LES and value of KYD remain in attractors reconstructed from ISI sequences.

发现周期信号在单个神经元传递过程中，随着激励频率的改变，神经元输出的峰峰间期interspike interval时间序列呈现出周期、混沌和准周期的交错变化，特别当外加激励信号频率较低时，周期信号可以通过神经元ISI序列以反相同步的周期运动形式传递下去；同时无论是周期还是混沌激励信号，在神经系统中的传递均与其自身强度和神经元之间的耦合强度的大小密切相关；快变时间尺度的混沌激励信号在耦合的神经系统传递过程中，会造成大量基本信息的丢失；而慢变时间尺度的混沌激励信号在神经系统传递中，它的非线性特征信息，如混沌吸引子、不稳定周期轨道、Lyapunov指数谱和分形维数，会通过系统输出的ISI序列部分地重现出来，如与输入慢变时间尺度的混沌激励信号相比，神经系统输出的ISI序列具有：相似几何形状的混沌吸引子、相近的Lyapunov指数谱和分形维数、局部结构相同的不稳定周期轨道的排列方式。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了