中数连续

It obtains that the transport operator A has no complex eigenvalue s,and the spectrum of the transport operator A consists of finite real isolated eigenvalues which have a finite algebraic multiplicity in trip Pas.

本文研究了板几何中一类具各向异性、连续能量、均匀介质的迁移算子的谱，得出了该算子A在带域Pas中无复本征值和由有限个具有限代数重数的实离散本征值组成等结果。

Finite Element Method is an important means of engineering subject and has been proved to be a common method in many subjects. However, disadvantages still remained. During the structural analysis, large amount of high-order units were used in order to ensure the precision of arithmetic solution when using Finite Element Method to do discrete processing. This will cause high order of coefficient matrix of corresponding equation group.

有限元方法是工程学科的重要工具，被证明为在许多科学和工程领域中连续物理系统模拟的一种普遍方法，但缺点是随着工程结构分析问题越来越复杂，在结构分析中，为保证数值解的精度，在使用有限元方法离散处理时，往往要用大量的高阶单元将结构剖分得很密，这时相应的代数方程组的系数矩阵的阶数很高，即使用目前速度最快的串行机来进行求解，费时仍然太多且问题的规模受到内存容量的限制。

The works in the project just done can be summarized as five respects.(1) A device was designed to fabricate the asymmetrical resonant cavities by a pendant drop. A series ARCs with variable parameters provides a valuable experimental method for investigating the characteristics of ARCs.(2) The relationship between the number of active modes and the shape parameters in an ARC was investigated. The experimental lasing threshold was compared with theoretical result, the good agreement between two shown that it was the decrease of the number of active modes in an ARC that decreased lasing threshold.(3) Dye lasing gain was used to enhance the signals of stimulated Raman scattering of the weak gain Raman modes in a circular cavity made by a pendant drop, the instantaneous SRS spectra of weak gain Raman modes in ethanol was obtained by this new method.(4) The SRS signals of minority compound in a binary chemical complex was obtained by using dye lasing gain method. The detection concentration of minority compound was reduced to an order compared with normal SRS method.(5) A cylindrical circular cavity was formed by a liquid jet, which was used to reduce the pump intensity required for laser induced plasma spectroscopy. The limit of detection of trace element in aqueous sample was greatly decreased by this new method.

我们设计并成功制作了使悬垂液滴连续变形的装置，用此装置可以方便地改变非圆对称谐振腔的几何参数，为ARCs的研究提供了一种有效的实验方法；研究了ARCs中活性模式数和变形参数间的变化规律，激光阈值的数值计算结果和激光辐射的实验结果作了比较，二者吻合的曲线说明ARCs中活性模式数量的减少是受激辐射放大阈值降低的原因；在由单元化合物构成的微型圆对称谐振腔中，首次尝试用"激光增益"增强弱增益拉曼模式的受激拉曼散射信号，获得了乙醇分子中弱增益拉曼模式的瞬态SRS光谱；在由二元混合物构成的微型圆对称谐振腔中，用染料的激光增益增强了少量化合物的SRS信号，把少量化合物的SRS信号探测浓度降低了近一个数量级，在SRS应用于瞬态过程的组份分析方面做了卓有成效的探索；用石英毛细管形成的稳定液拄构成拄形谐振腔，降低了激光诱导等离子体光谱需要的激励能量，有效地降低了水相样品的痕量元素分析极限，为LIPS应用于微量元素的化学分析开拓了一条新的技术路线。

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

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。

Considering the problems of spurgear precise plastic forming, such as high deformation resistance, poor flowability and especial hardness to fill cant of gear, technological plan was developed based on precise plastic forming technique, successive control principle and consecutive local deformation theory. Moreover, structures of the rolling preform die and the die with up and down wellrounded forcer for stamping-extrusion and bulge-extrusion combining forming were designed too.

因此本文的主要研究内容和结果如下：本文以某种直齿轮：模数m＝2，齿数z＝20，压力角α＝200，变位系数x＝0为对象，针对直齿轮精密塑性成形变形抗力大，流动性差，特别是成形中齿轮角隅部分更加难以充满问题，基于精密塑性成形技术、逐次控制原理以及连续局部变形原理提出了"直齿轮滚轧制坯－镦挤、胀挤复合精成形"的工艺方案，设计了滚轧制坯的模具结构和上下冲头带圆角的镦挤、胀挤复合精成形的模具结构。

You will hear someone sudden wealth in the stock market, what someone bankrupt is sad pleased, will also hear . someone earn million patrimonies in the stock market sudden risely, turn into naught in the slump again of regretful face. May 31th of 2007 goes to June a day, will be load in the historical work of the Chinese stock market, picking out pause to appear on market in three days, in 1432 stocks for be listed and traded fall to stop a number is 967s,400ses,804ses respectively, 270 among thoses stock falls to stop continuously for three days.

你在股市会听到有人暴富、有人破产的悲喜，也会听到有人在股市暴涨中赚得百万家财，又在暴跌中化为乌有的憾事。2007年的5月3 1日至6月3日，将被载入我国证券市场的史册，三天中，剔出暂停上市股，在1432只挂牌交易的股票中，跌停数分别是967只、400只、804只，其中270只股票连续三天跌停。

MWM engine makes the conversion among two-stroke mode, four-stroke mode and six-stroke mode of one engine come true in theory, filles in the blank with 1/3 which is the ratio of total strokes to working strokes in single working cycle of engine, possessing the continuous variable compression ratio of a certain range at the same time, combines the advantages of two-stroke engine and four-stroke engine, expandes the working range of engine greatly.

MWM发动机在理论上实现了一台发动机在二冲程、四冲程与六冲程工作模式之间的相互转换，填补了发动机单工作循环作功行程数与总行程数比值中1/3的空白，同时具备一定范围连续可变的压缩比，整合了二冲程与四冲程发动机的优点，拓展了发动机的工作范围。

As same as the above-mentioned reason, because theconditions at the inside straight boundary of the binarycomposite material can not be easily satisfied, here, anelastic circular inclusion with large radius is used to replacethe upper half space of the binary composite material, so the〓mary binary composite mater ial problem can be changed〓the scattering problem of a circular elastic inclusion andto the scattering problem of a circular eastic inclusion and〓circular cavity in an infinite space to the steady incident〓wave.

与前面两个问题的理由一样，同样，由于问题中双质复合材料的内部直边界上的边界条件不易解析满足，为此，本文采用了一个半径很大的弹性实夹杂来代替问题中双质复合材料的上半空间部分，而将原来的双质复合材料问题转化成了无限大空间中一圆形弹性夹杂和一圆孔对稳态P波的共同散射问题，根据该问题的特点写出了弹性夹杂内外波场中波函数的一般形式解，利用该问题中夹杂和圆孔处的位移和应力的连续条件，并采用复数傅立叶级数展开技术将其化为一个仅包含问题波函数中未知系数的无穷线性代数方程组，在满足一定计算精度的前提下，通过有限项截断进行近似求解，进而讨论了双质复合材料中圆孔边界处的动应力集中系数随不同入射角、圆孔的不同位置、以及入射波的不同无量纲波数的变化和分布情况。

Considering the problems of spurgear precise plastic forming, such as high deformation resistance, poor flowability and especial hardness to fill cant of gear, technological plan was developed based on precise plastic forming technique, successive control principle and consecutive local deformation theory. Moreover, structures of the rolling preform die and the die with up and down wellrounded forcer for stamping-extrusion and bulge-extrusion combining forming were designed too.

因此本文的主要研究内容和结果如下：本文以某种直齿轮：模数m＝2，齿数z＝20，压力角α＝200，变位系数x＝0为对象，针对直齿轮精密塑性成形变形抗力大，流动性差，特别是成形中齿轮角隅部分更加难以充满问题，基于精密塑性成形技术、逐次控制原理以及连续局部变形原理提出了&直齿轮滚轧制坯－镦挤、胀挤复合精成形&的工艺方案，设计了滚轧制坯的模具结构和上下冲头带圆角的镦挤、胀挤复合精成形的模具结构。

I can not make it blossom and suits me

我不能让树为我开花

When temperatures are above approximately 80 °C discolouration of the raceways or rolling elements is a frequent feature.

当温度高于 80 °C 左右时，滚道或滚动元件褪色是很常见的特征。