不变化地

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 influence of high temperature and high pressure on foaming agent's properties in opened and closed system, and influence of the change of foaming agent's properties on foaming capacity and foam stabilizing capacity are also studied. The multiple regression theory is used to establish the quantitative characteristic functions of foaming agent versus temperature and pressure. Based on the Gibbs Principle, the quantitative characterization is carried out on relation of foam system's free energy versus its surface tension, surface area and concentration, and the analysis of energy concluded that the disintegration of the foam is inconvertible. At the same time, the influence of change of foam's shape and structure on distribution of reservoir temperature and pressure is qualitatively described, and the coupling mechanism between temperature field, pressure field and chemical field is systematically expounded.

同时，研究了不封闭体系、封闭体系下高温、高压对发泡剂性质的影响，以及发泡剂性质的改变对其发泡性能、稳泡性能的影响；采用泡沫实验的相关结果，运用多元回归理论，建立温度、压力与发泡剂浓度的定量表征函数；基于Gibbs原理，对高温、高压下泡沫体系的自由能与其表面张力、体系中液体的表面积以及浓度关系进行定量化的表征研究，从能量的角度得出了泡沫衰变过程具有不可逆性；同时定性地描述了泡沫形态、结构的变化对油藏温度和压力分布的影响，系统地阐述了温度场、压力场、化学场间的耦合作用机理。

The scale analysis on planetary scale motion in the tropical atmosphere shows that the equilibrium between the pressure gradient force and Coriolis force in the meridional direction is easily established, which is known as the zonally semi-geostrophic motion The semi-geostrophic adaptation process in which the inertial gravity waves play an important part is relatively quick The evolution process after the semi-geostrophic adaptation process is slow and controlled by the Kelvin waves and long Rossby waves

对热带大气行星尺度运动所做的尺度分析和物理分析表明：热带大气的行星尺度运动在y方向容易实现气压梯度力与Coriolis力的平衡，它称为纬圈的半地转运动。半地转平衡的建立过程，也就是半地转适应过程相对是很短暂的，它不需要考虑f=β0y随y的变化，因而主要依靠惯性重力波为频散；而半地转平衡建立后的演变过程相对是很缓慢的，它主要受Kelvin波和Rossby波控制。

From the Warring States Period to the Qin Dynasty, the ancient myths and the ways of searching longevity indicated that the"God"concept was equal to the"immortal"which emphasized that the athanasy of the life is a"divine"nature, unlike ordinary people. In the Han Dynasty, the immortal concept undergone a subtle change, the god was becoming closer to the"human"existence. After the establishment of the Taoism, The Eastern Jin Taoist scholars Gehong established the immortal concept of Taoism,and put the"God"downgraded to longevity who practicing the longevous knowledge,and even established a"Dixian"concept. This completed the transformation process of"Shenren"to"Dixian"concept.

从战国至秦代神话的内容和古人探求长生不死的方式来看，最初&神&和&仙&的概念是一致的，强调的是神的先天不死性，体现为不同于凡人的&神人&概念，汉时的神仙思想发生了微妙变化，神仙逐渐变为接近于&人&的存在，道教创立后，东晋的道教学者葛洪把先天的&神&降格为懂得长生术的&人&，并提出了&地仙&概念，完成了&神人&向&地仙&概念的转变。

I consider the people who constitute a society or nation as the source of all authority in that nation, as free to transact their common concerns by any agents they think proper, to change these agents individually, or the organization of them in form or function whenever they please; that all the acts done by those agents under the authority of the nation, are the acts of the nation, are obligatory on them, and enure to their use, and can in no wise be annulled or affected by any change in the form of the government, or of the persons administering it.

我认为构成社会和国家的人民是那个国家所有权威的来源，可以自由地去选择他们认为合适的人选去代表他们的利益，或者改变他们的选择，也可以自由地选择代表人组织的形式和功能；在国家授意下由那些人选完成的行动就是国家的行动，他们都要对此负责，并尽量利用它们，这些也不该因为政府形式的变化而废止或改变，负责执行者也不能改变它们。老绿赞成的，我不能统统反对！

With the methods of experimental comparison and mathematical statistics,this paper makes the comparison between Star teaching model and traditional model.The main purpose is to discuss the better teaching model with the comparison,analysis,and induction of statistical data in three tests.The results show that there are more validities and rationality of Star model in the aspects of the effect of study,quantification of teaching,comparative analysis.

经过文献资料的比较和分析，现代定向越野运动无论在技术教学的基本观点上还是在技术的外形和内涵上都有了新的变化和发展，但方法还是比较单一，且大部分采用的是定性分析方法，分析体能、技能的构成、比重时只着眼于整体，一定程度上不够确切，不能细化地作定量描述，因而，学生对技术的分析、认识也必然带有相对的模糊性，不可能从技术的本质上作深入的分析，进而有效地解决问题。

In order to improve the efficiency, an implementing scheme (according to the distribution of strain energy density) was suggested when to consider the fact that the high gradient usually appears only in a very local region, especially in the case of huge amount of computation. All programming has been finished on the platform of commercial codes Mathmatica and Fortran.4. A number of numerical examples and applications were presented to verify the proposed Bezier-Based Element Method. The engineering cases include: the belt die for diamond synthesize, the main frame of wire-rounded press, the hydraulic cylinder of open die forging press. The numerical results show that the BBEM has some good performances.

通过大量的数值算例来考证所构建的各种类型单元，并应用于人造金刚石年轮模具、钢丝缠绕预应力机架和液压机工作缸等实际问题的结构分析；结果表明：所构建的Bezier耦合单元具有描述较大梯度变化场(如位移场、应力应变场等)的能力，该方法不改变单元的大小和形状，保持单元的自由度数不变，而通过调节中间可动节点的位置改变单元内部的场分布，只需少量单元即可较精确地模拟较大的梯度变化；可为有效求解高梯度问题提供新思路，对实际工程应用具有重要意义。

A number of numerical examples and applications were presented to verify the proposed Bezier-Based Element Method. The engineering cases include: the belt die for diamond synthesize, the main frame of wire-rounded press, the oil cylinder of open die forging press. The numerical results show that the BBEM has some good performances. With few elements, the BBEM can lead to a high accuracy. If using same DOFs, the computing precision of BBEM is remarkable higher than that of the conventional FEM.

通过大量的数值算例来考证所构建的各种类型单元，并应用于人造金刚石年轮模具、钢丝缠绕预应力机架和液压机工作缸等实际问题的结构分析；结果表明：所构建的Bezier耦合单元具有描述较大梯度变化场（如位移场、应力应变场等）的能力，该方法不改变单元的大小和形状，保持单元的自由度数不变，而通过调节中间可动节点的位置改变单元内部的场分布，只需少量单元即可较精确地模拟较大的梯度变化；可为有效求解高梯度问题提供新思路，对实际工程应用具有重要意义。

For each strategy, a corresponding exploitation plan of groundwater was designed. Then each designed exploitation plan (except scheme 3) was put into the model for calculation and simulation. The analysis on the forecasting results every plan indicates that:(1) Shuting down the self-provided wells is the most direct and effective method, playing an important role in the land subsidence prevention.(2) The resumption of compressed soil by groundwater artificial recharge is limited. So the artificial recharge can\'t provide essential effect for the resumption of land subsidence, unless the artificial recharge is much more than the groundwater withdrawal.(3) The method of "adjusting the exploitation stratum of groundwater to the shallow" has an obvious effect on the land subsidence prevention.(4)"Sand wells" can increase the leakage recharge for confined aquifer, and thus can slow and prevent the development of the land subsidence.(5) For the groundwater exploitation in Xi\'an, emergency self-provided wells should be managed according to the well spacing of 1600m, 2000m and 1600m, respectively, in the river terrace area, alluvial-proluvial fan area and loess tableland area to exploit the first confined groundwater. Corresponding individual well yield can be set as 2500m~3/d, 1500 m~3/d and 200 m~3/d. Make emergency self-provided wells pump in the dry year and stop pumping groundwater to restore and conserve underground water sources in average years and wet years. In this way, groundwater withdrawal of 162000m~3/d can be obtained to provide for the supplement of water supply in Xi\'an. As a result, the water supply stress can be released in dry years. The groundwater depression formed in the exploiting year can resume in 3-4 years. At the same time, this exploitation manner will not lead to obvious land subsidence.

本文利用所建的模型预测了现状开采条件下未来20年的地下水位和地面沉降的变化，在此基础上，提出了防治西安市地面沉降的五个地下水开采方案，利用所建的地面沉降模型对各个设计方案其进行了模拟和预报，对预测结果的分析表明：①封停自备井是防治地面沉降最为直接和最有效的对策，对防治地面沉降起着最为积极的作用；②采用人工回灌方法使被压缩的土层得到的恢复是非常有限的，对地面沉降不能起到根治作用，只有回灌量明显大于开采量时才能有一定的效果；③&调整开采层次，在浅层取水&对防治地面沉降的效果十分明显；④布设&砂井&可以增加对承压含水层的越流补给量，从而可以有效地缓解和控制地面沉降的发生和发展；⑤对西安市的地下水开采，可在河流阶地区、冲洪积扇区和黄土塬区分别采用1600m、2000m、1600m的井间距布置应急自备井，分别采用2500m~3/d、1500 m~3/d和200 m~3/d的单井开采量，开采第一承压水，在平水年或者丰水年不开采，涵养地下水源，在枯水年启动这些应急自备井开采，在输出分析范围内共可获得162000 m~3/d(5913万m~3/a)开采量，可以有效地补充西安市的供水水源，缓解供水紧张局面，开采年开采导致的下降的水位可在停采3～4年后得到基本恢复，同时，这种开采方式不会造成大的地面沉降量。

Large supply of non-hybrid seeds for vegetables, grains and herbs; make sure they are of the non-GMO, non-hybrid, propagating variety; also be sure to have instructions on how to harvest seeds including information on "moldering" techniques to properly collect seeds from certain plants such as tomatoes; note lastly that due to damp low-sunlight conditions many crops will not grow without growing lights and protection from rain; special research is therefore required on which crops will grow best (for instance, patty rice should grow better than wheat under damp conditions); also be sure to take into account the climactic change which results from the change in latitude due to the pole shift as a location which does not change greatly in latitude will fare better than one which falls in the vicinity of the new poles for instance; the pole shift theory presented on Zeta Talk states that the terrestrial North Pole will move to the middle of the Atlantic off the bulge of Brazil and ultimately one will need to observe the climate and the position of the sun to figure out the new latitude, and either adapt or re-locate as needed

要有许多蔬菜，谷物和草药的的非杂交种子；确信它们是非转基因，非杂交的，是用于繁殖的品种。也得确信具有怎样收获种子的指导书说明，包括&制造&技术方面的信息，以便恰当地收集某些植物的种子，例如西红柿。最后得注意，由于幽暗的低阳光环境，在没有阳光，以及没有其进行雨水防护的情况下庄稼将不会下生长。因而需要进行特别的研究，看看哪种庄稼在这种条件下生长得最好（例如，在昏暗的状况下，水稻应该比小麦生长的更好）。也要确信考虑了极移造成纬度改变，因而导致气候变化。例如，与那些位于新极点附近的地方相比，纬度变化不特别大的地方情况要好得多。齐塔人之声讲述的极移理论表明了地球北极会移动到大西洋中部的巴西隆起处。最后需要观察气候状况以及太阳的位置，以弄清楚新的纬度，根据需要，即可适应当地的条件，又可再次搬迁。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。