中计

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。

The quality of interior environment in nursing home residents will become one of the attention-getting subjects due to the gradual increase of aging populations This paper directs at the research of nursing home's interior environment factors in Tainan We use the standard of international practice to analyze the intrinsical data of environmental monitoring and establish the characteristics which from environmental physical reaction of nursing home The research items are air environments (PM10 CO CO2 formaldehyde TVOC) temperate environments and light environment (illumination average brightness daylight factor) etc There are the inductive conclusions of this research: 1 In basic medicine the clinical diagnosis means the theory and technique about physical examination with patients The definition of clinical diagnosis in architecture should be the diagnosis of building preserve and improve the feasible way to extend building's service life and assure the residents of the healthy quality of interior environment The object of clinical diagnosis in architecture is not only to ensure the use of structure and environment quality but also keep the structure and environment quality in sustainable; therefore creating an efficient system of preserving plan is needed 2 It is an accurate and technical circumstance which about improving remedying and reconstructing the problems of structure space This circumstance includes finding questions ensuring causation ascertaining ultimate strength evaluating environment quality estimating the necessary of restoration and implementing on a suitable way Furthermore when reconstructing and ameliorating the appearance of structure space it should be respected and the memories of it should be preserved 3 In clinical diagnosis of environment quality of space the question of physical environment and the deficiencies of structure must be separated The structure space of construction and the high quality of space should be inspected strictly then observed the crucial reason that can find out any invisible and hidden causes The diagnosis of construction is to observe the reason of destroyed structure The environmental diagnosis of indoor and outdoor is to find out the crucial reason that influences health 4 In order to decrease the iterant problems the construction and environment of space should be diagnosed However the destruction by natural strength and artificial using by human are important causes that can affect the service life of construction Searching the cause of disease just like curing the patient which includes inspection diagnosis cure and prevention We tested the thermal conductivity of siding material in this research and then found out the roof east vertical face and west vertical face have most radiant heat especially the construction of RC The characteristics of opaquely outer casing have relations with the thermal conductivity of wall to wiz the ability of heat insulation Therefore increasing the efficiency of heat insulation and decreasing the endoergic factor of insolation are very important to temperate environments

而随著国内老年人人口逐渐增加，逐渐迈向高龄化之同时，对於高龄者使用空间之室内环境品质相关议题之探讨，亦成为未来我们需加以关注之议题之一。主要为针对台南某安养中心室内环境因子进行检测调查工作，利用现场室内环境测定以取得有效的实测数据；再藉由汇整相关国际评估基准，并进行实测数据比对分析，建立老人安养中心对物理环境反应之特性。并以前期相关研究文献回顾与老人安养中心实测案例现场的实验，来了解不同空间物理环境特性之影响，并将结果回馈实际建筑及室内设计之用。调查工作项目包含：空气环境之PM10、CO、CO2、甲醛、TVOC；温热环境之室内温度、相对湿度、人体PMV、PPD；光环境之照度、均齐度、昼光率等因子调查。本研究结果可归纳以下几点结论： 1 所谓临床诊断医学乃相对於基础医学而言，是指实际与病人接触的医疗及护理行为中牵涉到的理论和技术；而建筑的临床诊断的定义应为建筑本体与室内外诊断、维护及改善所有可行的方式来延长建筑物的寿命，并确保人与室内环境空间品质的健康。建筑临床诊断目的为确保结构体与环境品质能继续使用，而能维持所需要的效能及承受能力。一个有效的维护计画体系是必须建立的 2 在建筑空间之问题改善、治疗与修复执行中，是一个精确与技术性的事项，其中包含找出问题、确定原因、评估结构应力强度、评估环境品质、评估修复与改善必要性、选择及执行一个适当的过程。其改善与修复也必须尊重建筑空间原有色彩与形貌，并保留原有记忆及文化。 3 在临床诊断中空间环境品质中，物理性环境问题与结构构件缺陷必须分别判断，诊断建筑空间之结构与空间舒适品质必须详细观察其症结性问题，才能发现任何隐藏及有潜伏性缺陷的原因。建筑本体诊断是观察出建筑本体之破坏原因，而是内外空间环境诊断目的在於的找出影响健康因素之症结性问题。 4 建筑本体与空间环境之预防评估目的为降低与抑制问题的再发生。然而，自然力的破坏与人为使用因素皆是影响建筑生命期之主要因素，找出病源问题就如同医生对病人的处理，包含了侦查、诊断、治疗以及预防。 5 本研究以外墙材料热传导率测试结果发现，屋面与东西向立面是承受辐射热最多的地方，尤以 RC 的建筑更甚，不透明部分的外壳能特性主要与壁体的热传透率即隔热能力有关，但是承受来自日射的吸热影响，因此增加隔热性能与降低日射吸热因子是对温热环境是非常重要的。

This may be due to hydrolytic chelating, precipitation and the sediment or hydrobioes attachment, absorption etc. The honewort had stronger ability of accumulating La because of its large leaf surface that could attach La. The accumulating ability of snail and fish to La was relatively weaker but some organs of them had higher contents of La especially in the intestines, shell of snail, and in gill, internal organs, scales, head, bone of fish, rare in muscle. The total accumulating quantities of La in each component of simulated aquatic ecosystem were a decreasing order of: sediment ＞honewort＞snail＞fish, and the sequence of bio-concentration facter was as follows: honewort＞snail＞fish.

2金鱼藻对La有较强的富集能力，主要通过枝叶表面吸附、吸收而富集；螺蛳对La也有一定的富集，并主要分布于肠、壳中，螺头中积累相对较少；草鱼对La的富集能力相对较弱，进入鱼体的La主要集中在鳃、内脏、鳞及头、骨中，肌肉中积累量较少；按质量计，稀土元素La在模拟水生态系统各部分中的积累量依次为：底泥＞金鱼藻＞螺蛳＞草鱼；各水生生物对稀土La的生物富集因子依次为：金鱼藻＞螺蛳＞草鱼。

The residual gas pressure in an electron tube can be measured when the tube itself is operated as a hot cathode ionization gauge.Usually,its sensitivity K is determined by the method of gauge calibration.In this paper,author try to determine the sensitivity K by ca- lculation.The formulae for this purpose have be found out,and are used for both plate and cylindrical electrode systems.

把电子管接成热阴极电离计的工作形式，用来测量管内残气压强时，其灵敏度如何计算的问题在本文中作了讨论，给出了平板形电极系统和圆柱形电极系统的灵敏度解析式，对式中各量的计算作了详细介绍；并指出四极管中电子在电离区的平均渡越次数的表示式与三极管中的完全不同。

The present invention adopts the technical proposal of adopting ZSM-5 mesoporous molecular sieve raw powder with a silicon-aluminum mol ratio SiO2Al2O3 of 20 to 1000 and a weight percentage of 20 to 100 percent as well as at least one caking agent selected from SiO2, clay and Al2O3 to extrude, tablet or spray into shape; then treating for 1 to 8 hours by 0.1 to 3 mol/l of at least one ammonium liquor from ammonium nitrate, ammonium chloride or ammonium sulphate or 0.1 to 8.5 mol/l of at least one acid liquor from muriatic acid, nitric acid, vitriol or acetic acid under a temperature of 20 to 90 DEG C; then using steam to treat for 2 to 15 hours under the temperature condition of 400 to 700 DEG C; using a liquor of 0.1 to 3mol/l selected from at least one of oxalic acid, citric acid or maleic acid under a temperature condition of 20 to 90 DEG C to dip for 2 to 5 hours to obtain the modified molecular sieve catalyst, thus better solving the problems.

本发明通过采用硅铝比SiO2/Al2O3为20～1000重量百分比计20～100％的ZSM-5介孔分子筛原粉与余量的选自SiO2、粘土或Al2O3中至少一种粘结剂挤条、压片或喷球成型；再经过0.1～3摩尔/升选自硝酸铵、氯化铵或硫酸铵中的至少一种铵溶液或0.1～8.5摩尔/升选自盐酸、硝酸、硫酸或乙酸中的至少一种酸溶液在温度20～90℃下处理1～8小时；然后在温度为400～700℃条件下水蒸汽处理2～15小时；再用0.1～3摩尔/升选自草酸、柠檬酸或马来酸中至少一种在温度为20～90℃条件下浸渍2～5小时得所需改性分子筛催化剂的技术方案较好地解决了该问题，可用于甲醇转化制丙烯的工业生产中。

But shooting the sun is tricky. On a clear day, the sun is so bright that your camera's meter will tend to underexpose everything else in the frame. Shoot in manual mode, or take a reading without the sun in frame, depressing the shutter button halfway to hold the exposure, then reframe before you shoot. If you're shooting film, bracket a lot to make sure of getting the exposure you want.

把太阳放在构图中以表达沙漠中的高温和荒芜，但拍摄太阳比较麻烦，晴空下的阳光影响相机的感光计，以至于构图中其它部分曝光不足，为避免这种情况，要启用相机的手动模式，或者是将太阳从构图中排除后，半按下快门固定曝光值，然后重新选择有太阳的构图，将快门按到底。

Theoretical analysis of strip mills AGC had been processed and a three-DOF mathematical model of hydraulic screw-down system had been built,which was specified cylinder displacement and inner gap and adapt to varied control way.

对板带轧机自动厚度控制模型进行了理论分析，建立了三自由度轧机负载的液压压下系统的模型，将缸位移和内辊缝相区分，使其适用于不同的控制方式，进而对厚度计式控制模型、变形的厚度计式控制模型、动态设定控制模型进行了对比研究，指出轧机模数和轧件塑性系数分别对应于自动厚度控制系统的静态指标和动态指标，为控制过程中参数的选取提供理论依据。

In this paper, a Pedestrian Tracking System is designed for handheld devices and implemented using accelerometers and magnetometers. It is composed of three modules: stepping module, stride module and direction module.

在本研究中，利用微机电系统实作了手持装置行人追踪系统，所使用的装置包括加速度计及磁力计；此系统包含了三个模组：计步模组、步距模组及方向模组。

In this paper,the analysis on the formula for magnetic resistance of magnetic circuit in a course of electromagnetism is presented .

通过分析现行大学物理《电磁学》教材中关于磁路磁阻计算公式的推导，阐明了该计算式是近似计算式，并对其适用性进行了讨论。

Displays with non-rectangular shapes are generally targeted to replace mechanical instrument gauges--such as the speedometers and tachometers found in cars--and other applications that require simple shapes.

非矩形的显示器一般是为了替代机械仪器仪表——例如汽车中的速度计和转速计——和其它需要简单形状的应用而设计的。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。