几何化

We thorough search the stable conformers of aromatic amino acids and arginine and examine the properties of the stable conformers using ab initio and DFT methods. The properties examined include the characteristics of intramolecular interactions, IR and UV spectra, temperature dependent conformer distributions, electron attachment and ionization energies, protonation/deprotonation processes.

木论文对芳香型氨基酸和精氨酸进行了理论研究，研究的性质包括几何结构、电子结构、构刑分布、电离能和电子亲和势、质子化过程、红外谱、紫外谱以及分子内相互作用等方面。

We also show their conservation properties of mass and energy and set up the corresponding erroe estimates in terms of the L〓-norm.

这样的离散化模型含有原连续模型的几何与物理特征，用它能够更好的模拟发展型微分方程的长时间的和全局的动力行为。

To further improve the robustness against geometric attacks, an image watermarking method is proposed based on normalized affine covariant regions.

3为了进一步增强图像水印系统对几何攻击的抵抗能力，提出了一种基于归一化仿射协变区域的水印算法。

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 displacement analysis of octahedral, decahedron and dodecahedral variable geometry truss manipulators are studied systematically.

提出了八面体和十面体变几何桁架机器人直接位置分析的符号解法，并得到了符号化的封闭解。

The experimental differential cross section data analysis with thetheory calculation code DWUCK4 using the distorted-wave Bornapproximation and zero-range interaction.

采用逐个事件的方法，用一事先产生的一系列点组成的数据库模拟探测器边界，事件的几何探测效率进行归一化，得到实际的实验室系散射角分布。

Use emulation mode to build parameterized model of straight and cylindrical gear wheel, not only can make the model change as the diversification of parameters but also can build accurately standard gear wheel.

用仿真加工的方法对直齿圆柱齿轮进行参数化建模，不仅能实现尺寸驱动模型，还能生成准确度较高的标准齿轮模型，该方法可为设计其它几何形状更为复杂的机械零件提供一定的帮助，具有较好的实用价值。

Use emulation mode to build parameterized model of straight and cylindrical gear wheel,not only can make the model change as the diversification of parameters but also can build accurately standard gear wheel.The ...

用仿真加工的方法对直齿圆柱齿轮进行参数化建模，不仅能实现尺寸驱动模型，还能生成准确度较高的标准齿轮模型，该方法可为设计其它几何形状更为复杂的机械零件提供一定的帮助，具有较好的实用价值。

Use emulation mode to build parameterized model of straight and cylindrical gear wheel, not only can make the model change as the diversification of parameters but also can build accurately standard gear wheel. The method advanced will provide some help or the designing of more complicated machine parts. It has a nicer practicability.

用仿真加工的方法对直齿圆柱齿轮进行参数化建模，不仅能实现尺寸驱动模型，还能生成准确度较高的标准齿轮模型，该方法可为设计其它几何形状更为复杂的机械零件提供一定的帮助，具有较好的实用价值。

For overlapping domain decomposition method, we prove the geometric convergence for continuous algorithm in the sense of energy norm by means of projection theory, analyze the convergence rate of the algorithm in detail. And we also discuss the discretization of the algorithm and its finite element implementation. Some numerical experiments are also given.

对重 叠型区域分解算法，利用投影理论，证明了连续型算法在能量模意义下的几何收敛性，详细地分析了算法的收敛速度，也讨论了算法的离散化及有限元处理，并给出了相应的数值实验。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐