稳态

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

The boundary conditions are assumed to be either the Dirichlet condition or linear Robin conditions.

在第一章，我们应用上、下解方法，bootstrap技巧和Schauder不动点定理考察如下三类周期反应扩散方程组的周期稳态解的存在性和一般的时变解的渐近性态：（1）拟单增系统；（2）混拟单调系统；（3）一个非拟单调2-系统，其边界条件是Dirichlet条件或线性Robin条件。

In Chapter 1, we use the upper and lower solutions method, the bootstrap technique and the Schauder fixed point theorem to investigate the existence of periodic solutions and the asymptotic behavior of general time-dependent solutions for periodic reaction-diffusion systems of the following three types:(1) Quasimonotone nondecreasing system;(2) Mixed quasimonotone system;(3) A nonquasimonotone 2-system. The boundary conditions are assumed to be either the Dirichlet condition or linear Robin conditions.

在第一章，我们应用上、下解方法，bootstrap技巧和Schauder不动点定理考察如下三类周期反应扩散方程组的周期稳态解的存在性和一般的时变解的渐近性态：（1）拟单增系统；（2）混拟单调系统；（3）一个非拟单调2-系统，其边界条件是Dirichlet条件或线性Robin条件。

Experimental study on the performance of system was worked out using electric heater as solar collector.

实验中，对系统的瞬态和稳态性能进行了测试，给出了系统在不同运行温度、压力下的产水速率和性能系数。

This design explains is basis of graduate design assignment book, combine bear on book that《electric equipment》、《electric system steady condition analyzing》、《relay safeguard》、《electric engineering specialty enchiridion of graduate design》,this is my summarize of three years in university .

本设计说明书是根据毕业设计任务书的要求，结合"电气设备"、"电力系统暂态分析"、"电力系统稳态分析"、"继电保护"、"电气工程专业毕业设计指南"等有关书籍而制定的，是我三年大学学习的总结。

Base on the mathematical equation: the quantity of conduction heat flex is equal to the product of heat conduction coefficient and gradient of temperature, we expect to obtain the result which is better than that of Transient Hot-wire Method and Steady-State Parallel-Plate Method, and simplify the strategy of measurement.

理论模式关系中，使用热传量等於热传系数与温度梯度乘积的比例关系式作为理论基础，目的在得到更优於暂态热金属线法(Transient Hot-wire Method)及稳态平行板法(Steady-State Parallel-Plate Method)的量测结果，同时也简化了量测方式。

A new discrete reaching law is presented to improve the reaching process of discrete exponential reaching law.The discrete-time variable structure control system designed by this reaching law can not only weaken the chattering and control the system state approach to zero diminishingly,but also keep the basic property of quasi-sliding mode which can cross the switching surface step by step.This method improves the reaching process and enhances the control quality of the control system.

为了改善离散指数趋近律的趋近过程，提出了一种新的趋近律，利用该趋近律设计的变结构控制器，不仅能够大幅度削弱抖振，使系统运动最终趋于原点不存在稳态振荡，而且能使系统的准滑动模态保持步步穿越切换面的基本属性，有效地改善了趋近过程，提高了控制品质。

Base on the in-depth analysis into the phase-to-ground fault mechanism and its features, the new concept is presented, which is to change the reference signal for analyzing and processing from the steady signal to the transient signal in a fault case A new principle of the fault feeder line selection with the synthetic logical criterion is presented creatively, which is based on the waveform recognition of the selected time-frequency window.

在深入分析单相接地故障的机理及故障特征的基础上，提出了从基于稳态信号原理转到基于故障暂态信号去分析和处理的新概念；创造性的提出了基于选线时频窗波形识别的综合性逻辑判据的故障选线新原理。

We obtain the transient distribution of queue length and probability generating function of queue equilibrium distribution.

研究了服务前需要重新调整机器的单重休假M~x/G/1排队系统，在LS变换和L变换下得到了服务员忙期中队长的瞬态分布和队长稳态分布的概率母函数。

However, because of its metastable characteristic and inaccessibility for direct-contact measurement, the specific heat capacity of supercooled metallic liquids is difficult to be completely determined by experiment.

由于深过冷态是一种极易发生相变的亚稳态，因此通过实验获取深过冷液态金属的热物理性质有些是不可能的，有些则是非常困难且代价昂贵的。

Plunder melds and run with this jewel!

掠夺melds和运行与此宝石！

My dream is to be a crazy growing tree and extend at the edge between the city and the forest.

此刻，也许正是在通往天国的路上，我体验着这白色的晕旋。