周期

Because of the lower coercive force and high damage threshold, the crystal is chosen and designed for six period patterns.

由于周期极化掺杂氧化镁的铌酸锂晶体具有较低矫顽场和更高损伤阈值的优点，所以选择了该晶体并在其上设计了6个周期图案。

If you have soft water, clean your coffeemaker after 80 brew cycles -- after 40 cycles if you have hard water.

如果你使用软质水，可以在咖啡机运行80个周期后进行清洗——如果你使用的是硬水，大可在其运行四十个周期后进行清理就可以了。

Double homoclinic loops; Resonant eigenvalues; Nontwist; Periodic orbit; Bifurcation; Periodic solution; Predator-prey system; Fixed point theorem; Coincidence degree; Delay; Functional response function

基础科学，数学，动力系统理论双同宿环；共振特征根；非扭曲；周期轨；分支；周期解；捕食者-食饵系统；不动点定理；重合度；时滞；功能反应函数

The expression level of metabolitic enzyme (CYP1A1, CYP1B1) and its correlation with cell differentiation /apoptosis were studied as well. The influence of resveratrol in cell cycle was determined with FCM. Results 1 Resveratrol not only suppresses the growth of medulloblastoma cells in a dose and time related fashion but also induces cell differentiation and apoptosis. Resveratrol promotes differention of UW228-1,-2 cells to forward glia, UW228-3 and Med-3 cells to neuron. A treatment of resveratrol in the concentration of 100μM for 48hrs comit most of cells die of apoptosis. 2 Among the four cell lines Fas and Caspase-3 were constantly expessed, whereas FasL was absent irrespective to the drug treatment. 3 ICC, RT-PCR, Western-blot hybridization and EROD enzymatic activity assay demonstrated that expression of CYP1A1 is different after treatment with resveratrol in four cell lines, up-regulated in three UW228 cell lines in a dose dependent manner but down-regulated in Med-3 cells. Suppressive effect of resveratrol on CYP1B1 expression is the same among four medulloblatoma cell lines. 4 Cell cycle distribution of UW228-3 was greatly changed after treatment.

结果：1、白藜芦醇以时间和剂量依赖性方式抑制髓母细胞瘤细胞生长，同时促进细胞的分化和凋亡：白藜芦醇促使UW228-1、-2靶细胞向神经胶质细胞方向成熟分化，UW228-3、Med-3细胞向神经元细胞方向成熟分化，以100μM作用48小时效果显著；2、四个细胞系均有Fas和Caspase-3表达，但无Fas-L基因表达和蛋白活性产生，因此难以形成Fas相关性死亡通路；3、白藜芦醇处理前后CYP1A1基因的表达在各细胞系略有不同：UW228-1，-2，-3三个细胞系白藜芦醇以剂量相关性方式上调CYP1A1的表达，而Med-3细胞系，白藜芦醇却抑制CYP1A1的表达；四个细胞系在白藜芦醇处理后CYP1B1的表达均受到抑制；4、UW228-3细胞系经白藜芦醇作用后细胞周期有较大改变，表现在G0/G1期在整个细胞周期中所占的比例增加，而其它时期则相应减少。

By using Floquet theory, Comparison theorem of impulsivedifferential equation and analytic method, we investigate the dynamics of thesystem in detail.

通过利用脉冲微分方程的Floquet理论和比较原理，证明了当脉冲周期小于某个临界值时，系统存在一个全局渐近稳定的害虫根除周期解，最后给出了系统持续生存的条件。3。

In this design, the dimension M of the memory vector field may be not necessarily equal to the dimension N of the network vector field. This may be the usually case in applications. Designing a network with either static or oscillating behavior, after analysing the dynamical. behavior of its four-dimension subspace, we get 2-torus in the subspace. If we vary the ratio of the imagine parts of the complex conjugate eigenvalues, the periodic motion of all kinds of period ratio on 2-torus are obtained.

设计一个既具有静态平衡点又具有动态振荡的网络，其静态平衡点由多余维叉形分叉得到，动态振荡形式由多余维Hopf分叉得到，通过对其中一个具有振荡行为的四维子空间的进一步分析，可以得到网络在四维子空间中的二环面运动，适当调整约当形中共轭复特征根虚部的比值，可以得到各种周期比的二环面上的周期运动。

Every fluctuation period of the earlier 4 cycles covered 0.75 to 1 Ma beingsimilar to that of the fourth-order glacial-eustasy with the interval of 0.1 to 1 Ma, imagining there probablyoccurred 4 fourth-order eustasies during the latest Ordovician from the D. complexus Zone to N. ojsuensisZone.

在前4次旋回中，每次波动的周期为0.75～1Ma，与冰川活动引起的Ⅳ级海平面变化周期(0.1～1Ma)相近，以此进一步推断晚奥陶世晚期(从D.complexus带到N.ojsuensis带)发生过4次Ⅳ级海平面变化。

Considering enough first integrals,such as conservation of energy and angular momentum,the system is integrable by Liouville's theorem.

利用能量积分，根据惠特克定理对系统的动力学方程进行降阶，并根据旋转数给出系统作周期或准周期运动的判别条件。

After a power spectrum is constructed, empirical wavelet coefficients are used to detect the jump points in the function to obtain the strong consistent estimator of the position and number of the frequencies. Numerical simulations show this method is reliable.

根据它们的协方差函数可以表示为一个Fourier级数，而其Fourier系数可通过协方差函数的逆变换得到的特性，我们对于零均值的近周期相关序列构造了类似于周期图的函数，并构造其经验小波系数，利用频率处于此函数的尖点的特性，以及此性质在经验小波系数中的反映，来确定频率的个数和位置，所有的估计量都是强相合的，此外，数值模拟的结果表明，我们的方法是有效的。

Through an infinitesimal contact transformation, the system was deduced to a torque-free rigid body with moments of inertia varying periodically with time. It can be taken as a Euler-Poinsot motion perturbated by small periodic excitation.

通过无限小接触变换，将系统等价为无力矩作用下自由刚体运动，但其转动惯量仍随时间周期地变化，从而化作周期摄动的Euler-Poinsot运动。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失