重要中心

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。

The optically active defect centers of such types as E', two kinds of oxygen-deficiency and some kinds of oxygen-richness in silica play an important role in optical communication fiber and UV absorption. The researches on some oxygen-deficient defects and the metal ions doped or implanted semiconductor nanoparticles with fine luminescence properties have made it possible for silica to be used in the lighting field.

氧化硅材料本征E'、2种缺氧型以及各种富氧型光活性缺陷中心在光导纤维及紫外吸收等应用中扮演了很重要的作用，某些具有良好发光性能的缺氧中心及掺杂离子或半导体纳米粒子发光中心的深入研究使氧化硅材料在照明领域具有良好的应用前景。

Dealcoholization temperature markedly influences the surface area and porosity of the resultant MAO-supports. When the support was pretreated at lower or higher temperature, the corresponding MAO-support shows very low surface area;2.XRD and IR analyses indicate that MAO has reacted with the residual ethanol in the supports, which is an important manner to get MAO fixed on the carrier. Morever, XPS analyse indicates that MAO can also be coordinated with MgCl_2, which is another way to get MAO fixed on the support;3.ICP and EDX analyses indicate that dealcoholization temperature not only determined the element content on the solid catalyst, but also influences the element distribution on the carrier;4.The activities of the supported phenoxy-imine catalysts and the properties of resultant polymers are strongly dependent on the dealcoholization temperature. The support (MSP-5) obtained by treating MgCl_2·2.56C_2H_5OH at 160℃for 4 h, then modified by MAO is very effective for immobilizing complex 3, the resultant solid catalyst (MSPC-5) shows very high activity in ethylene polymerization, and its kinetics of polymerization is stable during the reaction process. Finally, PEs with spherical morphology and high bulk density (over 0.35g/ml) were obtained, without reactor fouling;5.In this work, polymerization conditions such as alkylaluminums, Al/Zr ratio, temperature and H_2 had a pronounced effect on the activity of MSPC-5 and properties of PE;(3). New MgCl_2-Supported Single-Site Catalysts for Ethylene PolymerizationIn this work, a kind of new MgCl_2 support was obtained by anhydrous MgCl_2 co-milled with solid MAO, and it is a creative contribution. Then some single-site catalysts were supported on the new MgCl_2 support, and the resulted solid catalysts were tested in ethylene polymerization, the results indicated that:1.XRD and IR analyses indicate that MAO does be coordinated with MgCl_2, which is in good agreement with the results obtained by XPS;2.co-mlling time had no obvious effect on the texture of support after 12 hours;3.In this work, MgCl_2 was co-milled with solid MAO for different hours, and then complex 3 was supported on these co-milled supports. It was found that co-milling time markedly influences the activity of solid catalysts, but it had negligible effect on the kinetic profile and the properties of resultant PE.

XPS研究结果表明，MAO不仅仅只和乙醇作用，MAO还与MgCl_2本身有一定的作用，这是一个极为重要的发现；3、通过ICP和EDX表征，发现载体的脱醇温度直接影响着元素在固体催化剂中的含量及分布；4、脱醇温度极大地影响着负载苯氧基亚胺类催化剂的活性和聚合物的性能，特别是原始载体经160℃活化4小时制备得到的固体催化剂MSPC-5的活性明显高于其他脱醇温度条件下制得的固体催化，并且催化剂寿命长，表现出稳定的动力学行为，最终获得了高堆密度(大于0.35g／ml)的球形聚乙烯颗粒；5、本文选择MSPC-5为研究对象，考察了聚合反应参数对催化剂的活性及其聚合物的影响，研究发现：不同的烷基铝对催化剂具有非常重要的影响，特别足TIBA对MSPC-5的助催化活性最高，烷基铝的加入量有一个较佳值，聚合温度为80度时活性最高，H_2的加入使催化剂的活性明显降低且聚合物的分子量也减小；、新型氯化镁载体负载单活性中心催化剂催化乙烯聚合本文创造性采用固体MAO与无水氯化镁直接进行共研磨，制备出了一种的新型的氯化镁载体，并将该载体用于多种单活性中心催化剂的负载化研究，研究表明：1、通过BET、XRD的表征，再次证实了MAO与MgCl_2之间具有直接作用，与XPS的研究结果相一致；2、当研磨时间高于12小时时，延长研磨时间对载体的结构没有显著的影响；3、将配合物3负载于共研磨时间不同的一系列载体上，乙烯聚合结果表明，尽管共研磨时间对负载催化剂的活性具有明显的影响，但是它对聚合物的性能以及催化剂的影响不明显。

Dealcoholization temperature markedly influences the surface area and porosity of the resultant MAO-supports. When the support was pretreated at lower or higher temperature, the corresponding MAO-support shows very low surface area; 2.XRD and IR analyses indicate that MAO has reacted with the residual ethanol in the supports, which is an important manner to get MAO fixed on the carrier. Morever, XPS analyse indicates that MAO can also be coordinated with MgCl_2, which is another way to get MAO fixed on the support; 3.ICP and EDX analyses indicate that dealcoholization temperature not only determined the element content on the solid catalyst, but also influences the element distribution on the carrier; 4.The activities of the supported phenoxy-imine catalysts and the properties of resultant polymers are strongly dependent on the dealcoholization temperature. The support (MSP-5) obtained by treating MgCl_2·2.56C_2H_5OH at 160℃for 4 h, then modified by MAO is very effective for immobilizing complex 3, the resultant solid catalyst (MSPC-5) shows very high activity in ethylene polymerization, and its kinetics of polymerization is stable during the reaction process. Finally, PEs with spherical morphology and high bulk density (over 0.35g/ml) were obtained, without reactor fouling; 5.In this work, polymerization conditions such as alkylaluminums, Al/Zr ratio, temperature and H_2 had a pronounced effect on the activity of MSPC-5 and properties of PE;(3). New MgCl_2-Supported Single-Site Catalysts for Ethylene Polymerization In this work, a kind of new MgCl_2 support was obtained by anhydrous MgCl_2 co-milled with solid MAO, and it is a creative contribution. Then some single-site catalysts were supported on the new MgCl_2 support, and the resulted solid catalysts were tested in ethylene polymerization, the results indicated that: 1.XRD and IR analyses indicate that MAO does be coordinated with MgCl_2, which is in good agreement with the results obtained by XPS; 2.co-mlling time had no obvious effect on the texture of support after 12 hours; 3.In this work, MgCl_2 was co-milled with solid MAO for different hours, and then complex 3 was supported on these co-milled supports. It was found that co-milling time markedly influences the activity of solid catalysts, but it had negligible effect on the kinetic profile and the properties of resultant PE.

XPS研究结果表明，MAO不仅仅只和乙醇作用，MAO还与MgCl_2本身有一定的作用，这是一个极为重要的发现； 3、通过ICP和EDX表征，发现载体的脱醇温度直接影响着元素在固体催化剂中的含量及分布； 4、脱醇温度极大地影响着负载苯氧基亚胺类催化剂的活性和聚合物的性能，特别是原始载体经160℃活化4小时制备得到的固体催化剂MSPC-5的活性明显高于其他脱醇温度条件下制得的固体催化，并且催化剂寿命长，表现出稳定的动力学行为，最终获得了高堆密度(大于0.35g／ml)的球形聚乙烯颗粒； 5、本文选择MSPC-5为研究对象，考察了聚合反应参数对催化剂的活性及其聚合物的影响，研究发现：不同的烷基铝对催化剂具有非常重要的影响，特别足TIBA对MSPC-5的助催化活性最高，烷基铝的加入量有一个较佳值，聚合温度为80度时活性最高，H_2的加入使催化剂的活性明显降低且聚合物的分子量也减小；、新型氯化镁载体负载单活性中心催化剂催化乙烯聚合本文创造性采用固体MAO与无水氯化镁直接进行共研磨，制备出了一种的新型的氯化镁载体，并将该载体用于多种单活性中心催化剂的负载化研究，研究表明： 1、通过BET、XRD的表征，再次证实了MAO与MgCl_2之间具有直接作用，与XPS的研究结果相一致； 2、当研磨时间高于12小时时，延长研磨时间对载体的结构没有显著的影响； 3、将配合物3负载于共研磨时间不同的一系列载体上，乙烯聚合结果表明，尽管共研磨时间对负载催化剂的活性具有明显的影响，但是它对聚合物的性能以及催化剂的影响不明显。

Tianjin, one of the four municipalities directly under the Central Government, is the door of Beijing, capital of China. In 1997, the State Council described her as the economic center of the Bohai-Sea-Ring area, as well as an important economic center of northern China. This function description has the following meanings: on the one hand, the development of Tianjin must eradiate the Bohai-Sea-Ring area, the north of China and even the whole nation; on the other hand, it requests Tianjin to step up to a higher position, function and influence in multinational regional cooperation, and hence to form an important base and green channel on economy cooperation in northern China.

天津作为中国四大直辖市之一，是首都北京的门户。1997年国务院将其定位为环渤海的经济中心和我国北方重要的经济中心，这一功能定位意味着：一方面要求天津的发展要辐射于环渤海地区，辐射于我国北方地区乃至辐射于全国；另一方面要求提升天津在跨国区域合作中的地位、作用和影响，形成中国北方对外经济合作的重要基地和绿色通道。

Hal Broxmeyer, chairman and Mary Margaret Walther Professor of Microbiology/Immunology and scientific director of the Walther Oncology Center at Indiana University School of Medicine, said the new study "provides crucial, important, and physiologically relevant information on homing/engrafting capability … Most importantly, the results from this study open up the possibility of using a relatively simple means to enhance homing/engraftment and mobilization of" blood stem cells in bone marrow transplantation.

Mary Margaret Walther中心主席及微观生物学、免疫学教授、印第安纳大学医学院Walther 肿瘤中心科技主任Hal Broxmeyer称这一新的研究&为研究造血干细胞的移植/植活提供了关键、重要及生理学上相关的信息…最重要的是，这一研究成果开启了运用相对简便的方法增强&造血干细胞在骨髓移植上的&移植/植活及可移植性&。

In the eastern part of New Jersey lies the city o f Elizabeth, a major shipping and manufacturing cen ter.

伊丽莎白市，一个重要的航运和制造业中心，坐落于新泽西州的东伊丽莎白市，一个重要的航运和制造业中心，伊丽莎白市部。

Through the John and June Hechinger Commissioning Fund for New Orchestral Works, the Orchestra has commissioned more than 60 works, including cycles of fanfares and encores, which, taken as a whole, are representative of the diverse influences in American composition today.

此外，美国国家交响乐团还经常出访各国，并为各国首脑演出，因此在国际上享有重要地位。美国国家交响乐团成立于1931年，在历史上它一向致力于提供优秀的音乐演出。1986年，国家交响乐团成为肯尼迪艺术中心的下属单位，肯尼迪艺术中心是整个美国表演艺术的重要单位，自从1971年成立以来每年都推出音乐季演出。

The city ,America's famous--some might say infamous--Gateway to the West,is a hub for trade and transport.because of its mid-counry location,it also became a major point for the transshipmentof cattle(the city's famous Stockyards,or marshalling point for cattle driven from surrounding states to be sold,closed in 1971)and grain--as well as being an important commercial centre.

芝加哥，美国著名的西部通道，是贸易和运输中心。由于位于国家中部，芝加哥也成为牲畜和粮食中转的重要地点（城内有名的牲畜场或牲畜调车场于1971年关闭，这些牲畜从附近各州运进并售卖出去），同时也是一个重要的商业中心。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。