做模型

A theoretical model of this system, which combines convection and radiation, is established in this paper.

本文建立了这一对流辐射复合换热系统的理论模型；对不同情况进行了数值计算，并做了实验研究；分析了入口气流温度、风速、板数和板厚等因素的影响；从而确立了这一类问题的计算模型，精确地预测了实验结果。

The modification of the Gladman's model may then be proposed by the comparison of different models of grain coarsening with assumption of uneven in convexo-concave interface along grains. The modified Gladman's expression is given as: R_o =πr/3f_v(3/-2/Z) that may fairly predict the actual grain size observed.

比较了已有的晶粒粗化模型，在晶界面为凸凹不平的曲面前提下，对Gladman模型做了修正，提出了如下的修正Gladman公式： R_0=πr/3f_v(3/2-2/Z)该公式能较好地预测晶粒的实际尺寸。

Inflammatory model of Kunming mice ear edema induced by croton oil and determination combined with the LC-MS-MS-guided fractionation and isolation were used.

以巴豆油引起小鼠耳肿胀模型做为抗炎筛选模型，同时，在LC-MS-MS分析的导向下，寻找合欢皮抗炎活性部位。

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。

Finally, this thesis analyses the processing of variable weight on decision evaluation with the model of selecting matriculates based on Attribute Theor~ and analysis the characteristics of the model of selecting matriculates based on Attribute Theory The study in the thesis is helpful to further research and application.

最后，本论文分析了利用基于属性论高考招生模型的评价方法来处理决策评价中随着组态变化而变化的变权问题，并分析了基于属性论高考招生模型在决策评价中的独特性，本论文所做的研究有助于实际应用或进一步分析研究。

METHODS: Total 60 male Wistar rats were randomly divided into 6 groups, i.e., normal control group , DMN model group , large dose treatment group , middle dose treatment group, small dose treatment group and Dongbao gantai treatment group. The liver fibrotic model was induced by i.p. dimethylnitrosamine for 4wk. The relative herbs were given after model establishment in each treatment group and the administration lasted for 6 weeks. Decollate to get the blood and The serum hepatofibrosis indexes, hyaluronic acid, collagen IV, pro-collagen type III and laminin were measuredwith radioimmunoassay. SOD and MDA were measured with biochemistry method. The liver pathological changes were observed in each group of rats.

将60只雄性Wistar大鼠随即机分正常对照组、模型对照组、实验大剂量组(20ml/kg/d)、实验中剂量组(10ml/kg/d)、实验小剂量组(5ml/kg/d)及东宝肝泰药物对照组；腹腔注射二甲基亚硝胺制备大鼠肝纤维化模型，连续灌胃6周，断头取血，生化检测血清SOD、MDA；放射免疫法测定血清HA、LN、PCIII及IV-C；取肝左叶做HE染色和Mallory胶原染色，观察肝病理组织学改变。

Methods The distribution of fos-like immunoreactive neurons in telencephalon, diencephalon, midbrain and pons were examined in 10 "behavioral despair" rats and 10 "simple forced swimming" rats, and the distributions of FLI neurons of the two groups were compared by fos-Ab immunohistochemistry methods.

采用不同强度强迫游泳应激造成绝望行为模型和单纯强迫游泳模型大鼠（Wistar 系雄性，体重160～180 g）各10只，在其端脑、间脑、中脑和脑桥切片上各做抗fos蛋白免疫组化染色，40倍光镜下观察和计数各部位内fos蛋白免疫阳性神经元及其数目，并进行两组之间的比较。

Based on the simple global noise source, take the noise which is cared by people into account. Get the sound pressure level after processing the noise sources sound pressure. Educe the allowable value of the upper limit, through linking to the sound pressure level which is permitted. Taking the value into the reliability modals established before, found the diplex integral mathematics modals that is restricted.

考虑约束因素的影响，引入人们所关心的噪声，以结构简单的球形声源为基础，在对声源声压做了相对处理后，得到其声压级，结合许用声压级指标，求得许用频率上限值，将该值代入已建立的防共振模糊可靠度模型，建立有约束防共振模糊可靠度计算的双重积分数学模型。

On this basis a design scheme of the database for SCADA based on the component object model is presented, in which the content and background of IEC 61970 standard is introduced first, then some different component model are assayed , then a design scheme of the database for SCADA based on the component object model is presented, the foreground application of SCADA is connected with the database by components.The new model have some advantages: system have disrelation with develop language ,the peculiarity of COM make the system fit in with different apply program developed with different language;(2) the system can be modified and upgraded easily by means of upgrading the component modules;(3) the system can be enlarged easily by means of adding the new component modules without quiet amendment in old system.

为此，本文介绍了一种基于组件对象模型的SCADA数据库系统设计方案，文中首先介绍了IEC61970标准的内容及产生背景，分析了几种不同的组件模型，在此基础上，提出了一种基于COM组件技术的SCADA数据库设计及访问模式，在此模式下根据SCADA数据库不同的功用划分了不同的组件模块，利用组件连接数据库与SCADA前台应用，基于组件技术的SCADA数据库设计有以下一些特点：(1)与语言无关性，COM的特性决定了此系统上可以应用不同语言开发的应用程序；(2)系统易修改及维护，用户可以通过更新组件模块的方式修改及维护系统；(3)系统易扩展新的功能，用户可以通过开发新的组件方式将新的应用与原系统结合，而不用对原系统做很大的修改。

The first part presents develops of predator-prey systems and gives the model that is investigated in our paper; Chapter 2 presents the results on boundedness of solutions and permanence of system; In chapter 3, we explicitly derive a domain of attraction for the positive equilibrium of system by using Liapunov method; The local stability and the conditions that Hopf bifurcation occurs are obtained in chapter 4; In chapter 5, some explicit fomulae of the direction of Hopf bifurcation and the stability of bifurcating periodic solutions on the center manifold are determined,using normal form and center manifold introduced by Hassard et al; In chapter 6, some numerical simulations are performed to illustrate the analytical results found; Our paper ends with a brief conclusion.

全文共分七章，第1章对捕食-食饵系统的发展背景做了介绍并给出了本文研究的模型；第2章讨论了系统的保持性和解的有界性；第3章研究正平衡点的全局性质，对正平衡点的吸引域进行了精确估计；第4章研究了系统的正平衡点的局部稳定性和Hopf分支存在的条件；第5章利用规范型和中心流形定理得到了一个决定Hopf分支方向、分支周期解的稳定性及其他性质的精确公式；第6章对一个具体模型进行了数值模拟；第7章对全文进行了总结。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。