参数变化

It is well known that the properties of water in the critical region may show anomalies in many of its physical properties.

实验说明：地球内部流体性质由深到浅不断变化，如水的密度、介电常数等物理参数随温度压力而改变，在临界态出现突变。

The rupture failures of 3 crosshead pins of a hydrogen compressor are analyzed in respect of compressor train design,installation and variations of operating parameters etc,and corrective measures are recommended.

对同一台压缩机的三起十字头销断裂故障，从机组本身的设计，压缩机的安装及操作参数的变化等方面加以分析，并提出了对策。

This paper discusses the method of hypothesis testing on equation parameters,and the way of getting new equations to explain the speed, cceleration and jerk through calculating the differential coefficient of cubic equation.

该文还介绍了方程参数显著性检验的方法，并通过对方程进行多次求导，得到新的方程，来描述研究期间土地利用类型面积的变化速度、加速度以及加加速度。

Based on the model,the variations of the electrical parameters such as the potential barrier,the anode junction voltage drop,and the current amplification factor are studied and discussed.

在该模型的基础上，讨论了势垒、阳极结的电势降落和电流的放大因子等电参数的变化。

The JavaScript function sends in the current mouse coordinates and the delta that came from the zoom.

JavaScript发送当前鼠标的位置和缩放变化值作为参数。

According to Lemaitre's damage evolution law and the assumption of this paper that the cyclic loading maximum tensile stress has the most contribution to the cyclic damage and assume that the stress is the maximum stress .The material parameters S which are expressed in exponential form and generalize the variation in the process of cyclic loading is exponential experience equation which provide the expectation of cyclic damage of 63Sn/37Pb material and lead it into the calculation of damaged incremental form and assume that damage keeps constant during the same cycle. The results match the experimental data. It proves that the Endochronic plasticity theorem adopt the calculation of damage environment.

根据Lemaitre损伤演化律及本文假设循环负载下拉应力在最大值附近对循环损伤的贡献最大，文中应力对各循环之损伤而言假设应力为最大拉应力，将材料参数S以指数型式表示，归纳出疲劳损伤在循环负载过程中的变化为指数型经验式，提供63Sn/37Pb材料在循环负载作用时损伤情况的预测，并引入含损伤增量式内涵时间之计算中，假设同一循环的损伤为定值，其计算结果与实验数据吻合，说明内涵时间塑性理论亦适用於损伤环境下的计算。

The parametric method is used in the process of turbine parts modeling and tip clearance analysis. Due to the complexity of the turbine parts, some characters are predigested. A simplify high pressure turbine tip clearance model is analyzed with the cyclic symmetry method.

针对涡轮部件的结构特点，进行了适当的简化，利用参数化设计思想建立了涡轮叶尖间隙计算模型，用循环对称的方法分析了某型发动机高压涡轮叶尖间隙在工作过程中变化的情况。

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。

During construction, typical sections are selected to carry out the temperature field test and the elevation of girder of T structure is measured synchronously. The changing character of temperature gradient and its 2 key parameters are generalized and the deflexion of"T"structure is analyzed in view of temperature field.

在施工过程中，选取典型断面进行了温度场试验，并对最大悬臂状态的T构主梁的线形进行了同步观测，总结了温度梯度及其两个主要参数的变化规律，将三维温度场问题简化为一维温度梯度问题。

Spatial variations of a degree-day factor have great impacts on the accuracy of snow or ice melt modeling.

度日因子是该模型的重要参数，反映了单位正积温产生的冰雪消融量，其空间变化特征对于不同模型模拟冰雪消融过程的精度有较大影响。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐