查询词典 spectrum analysis

On this condition, some useful features have been found in the space domain. Wavelet spectrum estimation method has been used to extract the features in the space domain because the wire rope signal is a kind of none-stable signal. In order to discuss the physical meaning of this method, this dissertation proposes the relationship between Fourier spectrum and wavelet spectrum.

为进一步进行特征提取的需要，根据钢丝信号属于非平稳信号的事实，对信号给出了小波谱估计，以及Fourier谱和小波谱之间的关系和有效的小波谱计算方法，并在对实际钢丝信号小波尺度谱分析的基础上，给出一种信号的小波谱量化的方法，提取了信号的小波谱特征。

It is included the energy spectrum and angular distribution of hot electrons generated by ultrashort laser-solid interaction, the effect to electron behavior of electrical conductivity of target material, the hot electron activities and plasma characteristics in various plasma scale length, the rule of electron movement related to the high harmonic generation in gas, the excelled calculation about the condition of high harmonic generation, the study of electron spectrum and ion spectrum generated by Coulomb explosion in laser cluster interaction.

其中包括超短脉冲激光与固体靶作用中超热电子的能谱和角度分布，靶材料的电导率对电子行为的影响以及在不同的密度标长条件下超热电子和与电子相关的等离子体特征；超短脉冲激光与气体靶相互作用中与高次谐波相关的电子的具体运动规律和产生短波长高次谐波的优化条件；超短脉冲激光与团簇原子相互作用中通过对电子的隧道电离而引起的库仑爆炸等。

While calculating Sr spectrum by BSCR method we find: calculating the spectrum of Sr we can obtain pretty good results in low resonance energy if we use optimized β value of Ca directly, but it is not possible to obtain the ideal results in the part of high resonance energy spectrum.

我们使用BSCR方法计算Sr光谱时发现：将Ca的各open channel所对应的β值直接用在Sr的光谱计算时，在低能阶部分可得到相当错的成果，但是在高能阶时，则无法得到想的光谱。

By the use of standard substance, a standard spectrum library was established for 10 drugs, metformin, ephedrine, pseudoephedrine, caffeine, phenformin, fenfluramine, indapamide, phenolphthalein, fluoxetine and sibutramine. The identification for illegally added drugs was performed by comparing the accordance of retention time and the three-grade mass spectrum with the standard spectrum library.

利用标准物质建立10种药物（二甲双胍、麻黄碱、伪麻黄碱、咖啡因、苯乙双胍、芬氟拉明、吲达帕胺、酚酞、氟西汀、西布曲明）标准谱库，通过与标准谱库保留时间和三级质谱图的比较对非法添加的药物进行定性鉴别。

The job of later period, basically have the following these: Analysis and observation---Effect of analysis of user search behavior, keyword is evaluated, observation of search engine expression, change rate analysis and evaluate, search engine has the action inside frank analysis, station analysis, UE analysis and revise, competitor analysis and monitor,, if be a side a few large and medium-sized the website is done optimize.

后期的工作，主要有以下这些：分析与观察---用户搜索行为分析、关键词效果评估、搜索引擎表现观测、转化率分析及评估、搜索引擎占有率分析、站内行为分析、UE分析及修改、竞争对手分析及监测、资源站群推进、对话SE 实际上，如果是帮一些大中型网站做优化。

In this thesis, with the aid of the method of reconstructive direction cosine matrices of the analysis and synthesis of spatial mechanism, the more overall and systematic theoretical research is done about trident-bar universal joint and drawn some useful conclusions about kinematics analysis, dynamics analysis, kinematical precision analysis, vibration analysis, simulation and experimental results analysis, mechanism type selection analysis based method of fuzzy distinguishable pattern, integrated designing prototype system.

本文以改造的方向余弦矩阵为数学工具，以三叉式万向节为研究对象。进行了机构有关的解析求解、仿真和试验结果分析，基于模式识别技术的机构选型及机构的集成设计原型系统，得出了以下结论：(1)采用改造的方向余弦方法适用于空间机构的运动求解及动力求解。它的特点是解析明了，以矩阵方式体现，适合计算机求解。并以万向节为实例进行了万向节的详细的运动分析，建立了求解的各个变换矩阵，得出了机构的详细的运动关系。

ANSYS has friendly operating environment, strong functions and perfected post-processing. ANSYS can be applied to a lot of project fields and it can carry out structure analysis, nonlinear analysis, thermal analysis, electromagnetic field analysis, electric field analysis, fluid flow analysis and coupled field analysis etc.A combination beam is designed and on this beam simulation test using ANSYS and strength test using electrometric method are studied and contrasted. The result of the test shows that the ANSYS is reliable and can be applied to the engineering design and calculation without accident.

ANSYS软件是融结构、流体、电场、磁场、声场设计计算于一体的大型CAE软件，经过30多年的发展，取得了辉煌的成绩，并形成很多独有功能；ANSYS使用环境友好，功能强大，后处理技术完善；ANSYS在各类工程领域均有应用，可进行结构分析、非线性分析、热分析、电磁场分析、电场分析、流体流动分析、耦合场分析等；设计制造了一个组合梁，分别对其进行了ANSYS静力学强度数值模拟和电测法应力试验，对结果进行了对比分析，试验结果表明：ANSYS功能强大，分析数据安全可靠，可放心用于工程设计与计算。

Taking Changling County, Zhenlai County and Da'an City of Jilin Province as researchareas, based on remote sensing data, graphics operation and spatial analysis are carried out indifferent points of views, including temporal, spatial, scale and landscapeetc; all aspects analysis of this dissertation are abstractively expressed by digital graphics andseries of curves which are not stick to one pattern to discussing multi-dimension andcomplicated attributes of the salinized process. Linking up temporal-spatial characteristicswith landscape indices while combining mathematics model and Geo-informatic TUPUmodel, this dissertation puts forward the fundamental frame: temporal-spatial evolvementpattern, spatial extension process analysis and landscape characteristics analysis of salinizedland. Temporal-spatial evolvement pattern analysis extracts the essential quantity features andtransformation modes of salinized land, and also analyzes patches spatial geometricalparameters scale feature; spatial extending process analysis discusses the change rate andecological modes; landscape feature analysis utilizes landscape graphics indices to describesalinized land microcosmic graphics features and changes.

信息图谱模型为土地盐碱化研究提供了一种谱系化、定量化与定位化相结合的研究方法，本文选取吉林省西部盐碱化典型区域长岭县、镇赉县、大安市作为研究区，以遥感影像为基础数据，在GIS技术支持下，从时空变化、尺度效应、景观特征等多个角度对盐碱化土地进行图形运算、空间分析，通过不拘一格的数字化图形、曲线系列抽象表达出不同维度上的特征与规律，探讨土地盐碱化过程的多维性与复杂性，将盐碱化土地时空特征与景观特征衔接、数学模型与图谱模型结合，以盐碱化土地时空演变基本模式、空间扩展过程和景观特征分析为框架构建盐碱化土地信息图谱模型研究体系，发挥图谱模型数据挖掘、知识发现的特长，将宏观动态变化与微观特征相联系，进一步挖掘土地盐碱化过程与人类活动影响的关系，为探索研究区盐碱化土地成因、过程，预测其未来发展变化趋势及其对环境影响提供相关科学依据。

The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

理论分析和试验研究表明： 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的，具有摩擦动力学的本质，任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响； 2中心轴向载荷作用下，载荷增大使球轴承的固有振动频率升高，载荷越大同样的载荷增幅引起的频率升幅减小，足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响； 3轴向和径向联合载荷作用下，径向载荷不大时球轴承振动的固有频率基本不变，但是可能引起变刚度激励的非线性振动，出现新的频峰，过大的径向载荷将使部分钢球脱离接触，使球轴承的振动和噪声呈现不稳定状态； 4润滑对球轴承的振动和噪声特性有重要的影响，良好的润滑对振动有明显的抑制作用，润滑不充分时，振动和噪声的水平会有明显增高，一定条件下还会激发接触副中的谐振，发出啸声，造成接触表面的伤害，无润滑干接触时，短时的运转就会损伤接触副表面，使振动和噪声迅速增大，并随时可能引发严重的磨损和卡滞失效；接触副润滑良好时，油膜的"刚化效应"使球轴承振动的固有频率有所提高，润滑剂中含有弥散性污浊时，振动的幅度总体升高，但弥散性污浊不会改变球轴承振动的频率特性；浙江大学博士学位论文：球轴承振动的研究 5低速时，球轴承振动的基本特征呈现不稳定状态，随着转速的提高，球轴承振动的频率特性趋于稳定，固有频率频峰升高； 6理论分析表明，干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动，振动的幅值与谐波幅值成正比，实际球轴承中钢球的分布不可能完全均匀，波纹度的激励作用会随时发生；润滑接触的分析表明，波纹度的任意谐波分量均能激励球轴承的振动； 7球轴承的几何和结构参数分析表明，球轴承尺寸越大，径向、轴向和角振动的固有频率越低；钢球中心圆直径增大，球轴承的径向和轴向振动的固有频率基本不变，角振动的固有频率有所上升，振动的幅频特性基本不变；径向游隙加大使球轴承的径向振动固有频率降低，轴向和角振动的固有频率有所升高，径向振动幅频特性的幅值升高，而轴向和角向降低；钢球的数量增多使球轴承振动的固有频率上升，幅频特性的幅值下降，径向振动的幅值下降最为明显；外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高，轴向和角振动的固有频率降低，径向幅频特性基本不变，轴向和角向幅频特性幅值升高；内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降，振动幅频特性的幅值均有升高； 8试验对比表明，传感器采用探针式安装时，由于探针接触副接触特性的影响，钡(量得到的球轴承振动信号有失真，采用专门设计和制作的试验球轴承，以固定式安装加速度计，首次测量得到了球轴承振动的真实信号，通过对振动信号的分析，验证了球轴承振动的理论模型； 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析，以样本长度的均方根值作定阶上界，FPE做判阶准则，给出的AR谱光滑，频率分辨率高，是球轴承振动分析的简便而可靠的手段； 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间，时间间隔，频率范围，同样是球轴承振动分析的可靠的手段，可用作球轴承故障诊断技术。

Analyzed essential structure of spectrum analysis system of international, designed VUV excitation with 30W deuterium lamp and emission spectrum analysis system.

分析了国内外PDP荧光粉光谱分析系统的基本结构，设计了以30W氘灯为激发光源的真空紫外激发／发射光谱分析系统。

Diabetes is a social disease that affects several million people worldwide.

糖尿病是一个社会性疾病，全世界有数百万人罹患此病。

I'll call you on Friday to see if we can reschedule our luncheon meeting at your convenience.

我星期五会给您打电话在您方便的时候我们重新安排我们的午餐约会。