查询词典 oscillation

The paper consists of four chapters:In chaper 1, we introduce the background and signficance, research and actuality on oscillation of functional partial differential equations; we present research subject in this paper;In chaper 2, we discuss oscillatory property of systems of parabolic differential equations with delays and obtain necessary and sufficient conditions for the oscillation of their solutions; we show the difference between oscillatory property of systems of parabolic differential equations with delays and that of systems of partial differential equtions without delays; we explain the main results with examples;In chapter 3, we discuss oscillatory property of systems of functional parabolic differential equations of neutral type; we obtain some sufficient conditions for the oscillation or full oscillation of their solutions under some conditions; we explain the main results with examples;In chapter 4, we discuss oscillatory property of systems of functional hyperbolic differential equations of neutral type; we obtain sufficient conditions for the oscillation or full oscillation of their solutions under some conditions; we explain the main results with examples.

全文共分四章：第一章简要介绍了泛函偏微分方程的振动的背景和意义、对其研究的简单历史和现状，给出了本文的主要研究对象；第二章讨论了一类时滞抛物方程组解的振动性质，获得了判断其所有解振动的一个易于验证的充要条件；指出了这类具有时滞偏差变元的抛物方程组解的振动性质和不具有时滞偏差变元的抛物方程组解的振动性质的差异；并举例对主要结果进行阐明；第三章讨论了一类中立型抛物方程组解的振动性质，获得了在给定的条件下其所有解振动或全振动的若干充分条件；并举例对主要结果进行阐明；第四章讨论了一类中立型双曲方程组解的振动性质，获得了在给定的条件下其所有解振动或全振动的若干充分条件；并举例对主要结果进行阐明。

Firstly, the mechanism of heat transfer enhancement by oscillation heat surface is discussed in natural convection scene. For different oscillation amplitude and Rayleigh number, the frequency that the heat transfer rate of oscillation heat surface is higher than non-oscillation condition is found and called critical oscillation frequency. The limitation enhancement of similar physical model is still researched by this study in mixed and forced convection scenes for different amplitude and Grashof number. Generally, that a heat surface subject to a oscillation motion is advantageous to convective heat transfer is a well-known tuition.

首先探讨在垂直管道内振动高温面於自然对流领域内提升高温面热传效率的机制，并且针对不同的振幅与雷利数求得加入振动条件后，高温面散热效果可以优於稳态非振动高温面散热效果的临界振动频率；进而探讨当垂直管道流进入混合对流与强制对流范围时，在不同的振幅与葛瑞秀夫数下，亦可发现加入振动条件后，振动高温面之散热效果可以优於稳态非振动高温面散热效果的临界振动频率。

The experiment shows that:(1) In certain light intensity and electric field ranges (145～305V/cm) the material Si∶ with a resistivity of 1E4Ω·cm exhibits a current oscillation phenomenon at liquid nitrogen temperature;(2) At a certain electric field,the waveform of the current oscillation is stable and does not change with time;(3) The dependence relation between the oscillation frequency and light-intensity can be expressed by f=f0(L/L0)α where L0 is the minimum light-intensity needed to stimulate oscillation,f0 is the frequency under L0,L is the intensity of the light,and α is a coefficient that increase with electric field;(4) The modulating coefficient K K=(Imax-Imin/Imax decreases as the light increases;(5) The maximum value of the oscillation Imax decreases with the increase of the light-intensity while the minimum value of oscillation Imin increases slowly.

结果表明：在一定光照和电场范围内（276～305V/cm ，电阻率为10.4Ω·cm的材料在液氮温度下显示出电流振荡特性；在一定的电场下，电流振荡波形是固定的，不随时间变化；振荡频率随光照强度的增大而线性增大；调制系数随着光强的增强而减弱；振荡的最大值随着光照强度增大而减小，最小值随着光强增大而缓慢增大。

This paper compared continuous casting mold oscillation types between nonsinusoidal oscillation and triangle oscillation, analyzes their oscillation waves and oscillation parameter s.

本文对非正弦振动和三角形振动这两种不同的连铸结晶器振动方式进行比较，分析二者振动波形及振动参数，确定适合高速连铸的振动参数的选择范围，选出最佳的振动形式。

The oscillation performance of jet, as oscillation frequency, is the essential data for designing the fluidic device, which is also the key factor that influence the coupling effect of fluidic device and receiving tube. This paper does experiment on the oscillation availability and frequency of feedback jet-oscillation gas wave refrigeration. As a conclusion, the jet oscillates only in a certain range of geometrical sizes and operating conditions. Under the condition of high pressure ratio, the frequency of the jet"s oscillation is only affected by the feedback tube"s length and chamber remarkably. Under the condition of low pressure ratio, the frequency descends with rise of the pressure ratio.

本文将跨音速正反馈射流振荡器与接受管耦合，对耦合后的射流振荡气波制冷机的可振性、振荡频率以及它们的影响因素作了实验研究，得出如下结论：射流只在一定的操作条件和几何结构尺寸范围内才能稳定振荡；射流的振荡频率在较高压比下只受反馈管长和反馈管容腔大小的显著影响，在小压比下随压比的增大而增加；其它结构尺寸和操作条件只影响可振性。

Firstly, the mechanism of heat transfer enhancement by oscillation heat surface is discussed in natural convection scene. For different oscillation amplitude and Rayleigh number, the frequency that the heat transfer rate of oscillation heat surface is higher than non-oscillation condition is found and called critical oscillation frequency. The limitation enhancement of similar physical model is still researched by this study in mixed and forced convection scenes for different amplitude and Grashof number.

首先探讨在垂直管道内振动高温面於自然对流领域内提升高温面热传效率的机制，并且针对不同的振幅与雷利数求得加入振动条件后，高温面散热效果可以优於稳态非振动高温面散热效果的临界振动频率；进而探讨当垂直管道流进入混合对流与强制对流范围时，在不同的振幅与葛瑞秀夫数下，亦可发现加入振动条件后，振动高温面之散热效果可以优於稳态非振动高温面散热效果的临界振动频率。

Therefore, the multi-stage interaction structures with losses and severed structure were more stability for absolute instability and gyrotron backward oscillations. This study presents a nonlinear analysis of typical oscillations, including absolute instability, gyrotron backward oscillation and reflective oscillation. The multi-stage gyro-TWT seem to increase effectively the start-oscillation currents of the absolute instability, gyro-BWO, and reflection oscillation.

所以在本研究分析中，藉由了解磁旋行波放大器中的自发振荡物理原因及特性，将有助於高功率放大器的设计，并且引用非线性程式进行磁旋行波放大器稳定分析，并且采用兼具隔离管及散布式损耗结构的磁旋行波放大器，同时提升绝对不稳定、磁旋返波振荡及反射振荡的稳定性能有效提升磁旋行波放大器输出功率和频宽。

He proved that the left ward turning of Yangtze river diluted water is mainly resulted from the interaction between the bottom declining and the lag of the transversal pressure gradient, made the numerical simulation and preliminary study on the thermohaline staircase structure formation mechanism, improved American Academician Wunsch's inverse method of ocean circulation, jointed the discover of " Mindanao Under Current", which is the first ocean current found and named by Chinese scientists and widely accepted over the world, simulated the horizontal and vertical carbon fluxes in East China Sea by a simple ecosystem model, estimated the photosynthesis efficiency less than 8% in Jiaozhou Bay, applied statistical downscaling technology to Chinese coast and Japanese islands realizing the simulation and forecast of sea level low frequency variations, pointed out that the quasi-periodicity of El Nino events should be resulted from the interaction between the 3~4 year oscillation in tropical Pacific and decadal oscillation in the northern Pacific of middle latitudes of the air-sea coupled climate system and at decadal time scale the precipitation influence on sea level variation along Chinese coast and Japanese islands becomes more important, which is closely related to the decadal oscillation of air-sea coupled climate system, therefore precipitation most likely play a major role for the decadal oscillation formation;; proposed Extended Associate Pattern Analysis to analyse combined observed datasets of sea surface temperature and sea level pressure or geopotential hight at 1000 hPa (GH1000) over the Pacific and related seas.

论证了长江冲淡水向左转向主要由于底形下倾与横向压力梯度滞后相互作用的结果。对温盐阶梯结构的形成过程及物理机制进行了数值模拟与初步探讨。改进了美国科学院院士Wunsch的大洋环流反演法。与胡敦欣院士共同发现了"棉兰老潜流"，这是第一支由中国科学家发现、命名并得到普遍承认的洋流。借助较为简单的生态模式数值模拟了东海的水平与垂直碳通量；胶州湾浮游植物的屏蔽效应可以使底层海水温度在升温季节降低2度，由此推算出其光合作用的效率应小于8%；浮游植物春季水华的生物过程实际上强化了海水层化的物理过程。将统计学降尺度技术应用于日本列岛和我国沿海，实现了海平面长周期变化的模拟与预报。

Chapter 3 emphasizes on the case that the considered systems contain not only impulse but also time delay. We mainly investigate impulsive parabolic systems with time delay and neutral impulsive parabolic systems. Section 3.1 discusses the oscillation of impulsive parabolic systems with time delay under Robin boundary condition and obtains some useful criteria via first order impulsive differential inequalities with time delay. Section 3.2 studies the oscillation of neutral impulsive parabolic systems under Neumann boundary condition and Robin boundary condition, respectively, and obtains some sufficient conditions for oscillation and strong oscillation via first order neutral impulsive differential inequalities.

第三章针对于"脉冲"与"时滞"共存的复杂情形，仍采用反证法讨论了含时滞的脉冲偏微分系统的振动理论，具体研究了脉冲时滞抛物系统和中立型脉冲时滞抛物系统。3.1节考虑了脉冲时滞抛物系统的振动理论，借助于一阶脉冲时滞微分不等式的解的性质，得到了满足Robin边界条件的脉冲时滞抛物系统的若干振动准则；3.2节考虑了中立型脉冲时滞抛物系统的振动理论，借助于一阶中立型脉冲时滞微分不等式的解的性质，分别给出了满足Neumann边界条件和Robin边界条件的中立型脉冲时滞抛物系统的若干振动和强振动准则。

The electric potential oscillation including periodic oscillation,quasi- periodic oscillation and turbid oscillation of carbon steel/H2SO4＋ K2Cr2O7/Pt system has been studied.

刘靖研究了碳钢/H2SO4+K2Cr2O7/Pt体系中的电位振荡现象，如周期振荡、准周期振荡和混沌振荡等，并对其振荡机理进行了初步分析和讨论。

The work of this paper is as follows: 1. Looking back the progressing history of the linear motor, introducing the features of the elevator driven by linear induction motor, radicating the topic of this paper "the digital frequency variable control of the elevator bi-side direct driven by linear induction motor". The research of this paper covers the conventional VVVF control, space vector based VVVF control, vector control and DTC.

本文主要开展了以下几个方面的工作： 1 回顾了直线电机发展历史，电机的驱动技术演变，特别是针对直线电机的驱动，简要介绍了直线感应电机驱动电梯的优点和不同结构类型，对传统的v／f控制，基于空间矢量法的v／f控制，矢量控制，和基于电压空间矢量的直接转矩控制进行了比较，确立了本课题的研究主题：直线感应电机双边直推式驱动电梯的全数字变频控制。

The article combines with the treatment of a superficial civil air defense work to introduce how the grouting method to improve the performance of the backfill soil.

文章从治理漂浮人防工事的角度提出了注浆技术在改善回填土性质方面的应用，并详细阐述了注浆技术的施工流程。