查询词典 load

From the statistical meaning of random load action, the cumulative distribution function and probability density function of equivalent load are developed according to the property of order statistics when load acts for many times.

从载荷作用的统计学意义出发，根据顺序统计量的性质，建立载荷多次作用时等效载荷的累积分布函数和概率密度函数。

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。

Through calculation and analysis of static modal under dead load, live load and water load, we derived the non-seismic internal force and deforming of the structure.

通过对静力模型在恒载、活载和水荷载作用下的计算和组合，得到了结构非抗震设计的内力和变形。

Situations of live load and dead load of vehicles and equipments as well as pile load of the surrounding griund of foundation pit etc.

施工期间基坑周边的地面堆载及车辆、设备的动、静载情况等

ABSTRACT: A Rockwell PowerFlex7000 Variable Frequency Drive is used in JiuZHou Electric medium voltage drive test bay as the converter. Because of it belong to the current source drive, it has the function of the four quadrant, it can achieve the energy feedbackmake the motor brake,also has the advanced vector control technology, so it can achieve all kinds of load test, there are no other drives can replace it in simulate motor load. PowerFlex7000 drive has ability to achieve the full load test before the drive leave factory.

摘 要：罗克韦尔PowerFlex7000变频器在九洲中压变频实验站测试系统中作为变流逆变器使用，由于本身属于电流源型变频器，具有四象限运行功能，能够实现能量的回馈和对电机的制动，先进的矢量控制技术，可以实现各种复杂多变的负载特性，在模拟电机负载方面起到了其他变频器无可替代的作用，实现了变频器出厂之前的满负荷测试。

A bstract: Load Identify has always been one of the important aspects in dynamics. This paper gives us a new way to identify one point dynamic load which is act on a sheet. The method is based on the modal theory and Duhamel integral. Result obtained from a simulation indicates that the method is simple and easy to operate especially when it is used to identify transient load.

载荷识别一直是系统动力学研究领域重要的一方面，本文以平面薄板结构为例，基于模态叠加理论，从 Duhamel积分出发，考察无限自由度系统在单点激励动载荷作用下的载荷识别问题，本文提出的方法具有简单、易操作等特点，通过仿真分析，其对于瞬态激励有比较好的识别精度。

Bymeans of analytical model of dynamic air conditioning load in department store andits calculation with DOE-2, dynamic cooling load of department store in 8 typicalcities have been obtained, from which load pattern of CVAV system has beenanalyzed.

通过建立商场建筑的空调动态负荷分析模型，并采用美国建筑能耗分析软件DOE-2对其计算，本文得到了八个典型城市商场建筑供冷期间的动态负荷，在其基础上，对组合变风量空调系统的负荷特性进行了分析。

After you create your load test, you can edit the load pattern in the Load Test Editor.

创建负载测试后，可以在负载测试编辑器中编辑负载模式。

This paper studies the influence of country economy guideline in power demand. According to identifying the main economy and society factors in affecting the change of Fujian power demand, the power demand forecast model is proposed. And the demand curve models fitting for diversified users are built by researching the influence of electrovalence to power demand.The influence of demand side management in load characteristic of Fujian power system is analysed.Used the arithmetic of modifying the history load curve, this paper forecast the changing and development trend of Fujian load characteristic.

本文研究了国民经济指标对电力需求的影响，通过识别影响福建省电力需求变化的主要经济社会因素，建立电力需求预测模型；研究了电价变化对电力需求的影响，对各类用户建立适合各自特点的需求曲线模型；分析了需求侧管理对福建电网负荷特性的影响，采用历史负荷曲线修正法，预测了福建电网负荷特性的变化发展趋势。

Secondly this dissertation made the statistical analysis of brittle ice load, and results showed that there was a greater variance of ice load during slow ice speed movement and a smaller variance of ice load during fast ice speed movement.

其次对冰脆性破坏时的荷载进行了统计，结果显示当冰速较慢时荷载的变化较大，而当冰速较快时荷载的变化较小。

Vishnu entered a dark fourth dimensional dream that did not support his field or continued life.

毗瑟挐进入了一个第四密度的黑暗梦想，那里并不支持他的能量场或继续生命。

Leaders and decision-making persons use it to collect the data, including the information of unit work, handing in fee, oweing fee, prepaying fee,changing and afterpaying and account transfering of joining-insurance employee, and account paying of all kinds of insurances from hospitalization insurance institutions.The collected data is picked up, organized, switched and showed to user.

该子系统主要面向各级领导、决策分析人员；从各个医疗保险经办机构和定点医疗机构采集数据，包括在各个医疗保险经办机构处理的单位办公信息，单位缴费、欠费、预缴费信息，参保职工变更信息，参保职工增减变动信息，参保职工补缴信息，参保职工帐户划拨信息：包括各定点医疗机构处理的各险种帐户支出信息，各险种的统筹金支付信息等；将采集的数据提取，组织和转换，然后展示给用户。