曲线角

Based on varying process of generator terminal parameters after excitation fault, shortages of excitation protective principle of static stability boundary and asynchronous impedance boundary are analyzed. It proposed that excitation fault research relates to large-disturbance stability. Because dynamic power-angle character of generator after excitation fault is non-sinusoidal, there are differences between dynamic power-angle character and static state power-angle character. So it isn't ideal to protective operation result based on small-disturbance stability and static stability boundary criterion. At the same time, it proposed that asynchronous boundary impedance criterion is a constant reactive power circle moving adown j Xd′. It can ensure complete loss-of-excitation generator measuring impedance enter into the circle, but can't ensure the other condition measuring impedance including impossible losing synchronism enter. So loss-of-excitation protection would be maloperation when system voltage drops short and recovers or generator rejects load.③Based on stability principle, it puts forward setting conditions and calculation method of generator loss-of-excitation protection by direct measuring power-angle.

以励磁故障后发电机端的相关参数的变化为基础，通过对以静稳定边界和异步阻抗边界作判据的两类三种现行励磁保护在原理上存在的缺陷分析，发现：励磁故障是一个大干扰稳定性问题，励磁故障后的发电机的动态功角特性与静态功角特性有很大的差异，已远非正弦曲线，因此基于小干扰稳定性原理、以静稳定边界作判据的保护必然动作不理想；异步边界阻抗判据是一个下移j Xd′的等无功阻抗圆，它可以保证完全失磁后的发电机测量阻抗能进入该阻抗圆，但不能保证完全失磁之外的其它状态不会进入该阻抗圆，因此在系统电压短时下降或发电机突然甩负荷等情况下可能启动该保护使之误动。

The apparatus adopts the technique of one-chip computer,can set ignition advance angle at random rev of the engine at any time and assists the power test of the engine.The apparatus can survey and describe the best ignition advance angle curve of motorcycle engine and affords gist for the design of motorcycle engine and ignition control.

该仪器采用单片机技术，能够在任意发动机转速下设定任意点火提前角，配合发动机测功试验，可以快速测绘出摩托车发动机最佳点火提前角曲线，为发动机和点火器设计提供依据。

For the key of vector- Distance algorithm , Curve fitting is used for the derivation of deviation angle algorithm, demonstrating the feasibility of deviation angle Algorithm and the error analysis.

针对矢量距离算法的关键，采用曲线拟合对计算偏离角的关系式进行了推导，论证了偏离角算法的可行性，对算法进行误差分析，用归纳的方法推导出计算磁短节中点与直井之间距离的关系式。

The position and size of the monochromator, focusing curvature radii and tilting angles of the germanium focusing monochromator under different different take-off angle, size and divergency of the second collimator and intensity loss due to the use of it were determined. The neutron flux at different wavelength, under different reflection and take-off angle of the monochromator and divergency of the first collimator, were given. The simulation on the aperture used for limiting beam size in front of the sample showed that, smaller the size of the aperture and further the distance from the aperture to the sample, greater the loss of the intensity and more serious the spread of the beam along vertical direction at the sample position which makes the practical sampling volume greater than expected.

用蒙特卡罗模拟方法对中子应力衍射谱仪的设计方案进行了优化研究，提出了一系列可供参考的数据：确定了单色器的位置、尺寸、垂直聚焦单色器在不同起飞角下的聚焦曲率半径和倾角；讨论了第二准直器的尺寸和发散，以及使用第二准直器造成的强度损失；给出了在不同单色器反射面、起飞角、中子波长和第一准直器发散度的情况下样品处的中子注量率，以及多种组合情况下谱仪的分辨率曲线；对限束方孔的尺寸、距离样品远近对强度损失和测量中的影响做了深入研究。

Calculation of teeth profile of disc cutter for arc-gear;2. The formulas for setting angle and entrance angle of disc cutter s are derived by using the contact condition of space curve.

利用空间曲线相切条件导出了用于计算盘形刀具安装角和切入角的条件；该方法具有以下优点：无需知道工件齿形，可同时获得刀具宽度、半径等参数。

The similar drawing of the hyperbolic line is argument according to my experience with teaching, which is on the head surfaces of hex nut and used in the engineering drawings, through building three-dimensional model in AutoCAD.

本文通过在AutoCAD中建立三维虚拟对比模型，探讨了工程图样中六角螺母和六角螺栓头部外表面双曲线在计算机辅助设计中的近似画法问题。通过对比，论证了样条曲线替代圆弧近似双曲线改进画法在计算机绘图中的合理性和优越性。

Results: The PCNA mean labelling index was 48.84％± 13.63％, and the apoptotic labelling index was12.26‰± 5.20‰. The Kaplan-Meier survival curves showed that the postoperative survival time of the patient was shorter when the tumor infiltrated to the adventitia of esophagus,with lymph node metastasis, without keratinization, PI ≥ 40％ or AI＜10‰. Using forward multivariate Cox regression analysis, only the parameters of pN category and PI could be verified as independent prognostic factors.

结果：36例手术切除的食管鳞癌组织平均PCNA表达指数(PCNAlabellingindex，PI)为48.84％±13.63％，细胞凋亡指数(apoptosisindex，AI)为12.26‰±5.20‰；PI升高与患者年龄小、分化程度低、有淋巴结转移和肿瘤进行性浸润呈正相关，而AI升高与分化程度高、角化明显呈正相关；绘制Kaplan－Meier生存曲线，发现病变侵及食管外膜、有淋巴结转移、无角化、PI≥40％或AI＜10‰的患者术后生存率明显降低；COX比例风险模型分析，发现只有淋巴结转移和PI是影响预后的独立因素。

For feature extraction, this dissertation studies Barnard algorithm for Edge Point extraction and SUSAN algorithm for Corner extraction, Afterward, I put forward a method to extract inflexions, straight lines and curves based on Freeman Differential Code. Thus the use of Freeman Code can be extended and there will be more approaches to finish stereo correspondence.

在特征提取部分，本文对传统的Barnard边缘点提取、新近的SUSAN角点检测等技术做了详细的分析和研究，并在此基础上提出了基于Freeman差分码的多特征提取方法，包括拐点、直线及曲线，而且提取的直线利用多直线段分解法进行拟合，提取的曲线利用B样条技术进行拟合，最终形成有意义的轮廓。

During the pipe pushing construction of the parallel steel water pipeline of Beidu-Yanger pipeline project in Ningbo, the pushing force in main pushing power station appeared unusual increasing and the construction had to be interrupted. Through the analytical comparison between theoretical and practical pushing curves as well as the analytical comparison between the tool pipe track and the form map of pipeline resting in soil, it was found that the excessive pushing force in main pushing power station was caused by excessive deviation adjustment angle which enabled the pipeline to over bend in a short distance.

在宁波市北渡－雅戈尔原水D1800mm钢管复线工程顶管施工中，出现主顶动力站顶力异常增大的现象，影响继续顶进施工，文章针对这一情况进行分析研究，通过理论顶力曲线与实际顶力曲线以及工具管所经轨迹与管道在土层中静止时的形态图的分析比较，得出主顶动力站顶力过大是因为在纠偏过程中纠偏角度过大，使管道在短距离内过度弯曲引起的。

The power of motor is positive proportion to square root of equality of square pure torque .the pure torque is combined by suspension point torque and balancing weight torque ,so the change of suspension point's motion law and balancing weight offset angle can causes pure torque variation .especially, the suspension motion law is decided by configuration curve of hinder heaven sheave .so the paper has emphatically studied and analysis the law that the configuration curve of hinder heaven sheave brings the change of pumping unit energy-saving .

电机功率与减速器曲柄轴净扭矩均方根成正比，减速器曲柄轴净扭矩是由悬点载荷产生的扭矩和平衡重产生的平衡力矩合成的；改变悬点运动规律和平衡重的滞后角可以引起净扭矩的变化，其中悬点运动规律是由后天轮曲线决定的，因此，本文依据此原理着重研究分析了后天轮曲线影响抽油及节能的变化规律。

The basic concept of FOP can be summarized as to further optimize effective prescription according to the standard of curative effects and with the aid of modern science and technology and theories of traditional Chinese medicine.

其基本内涵可概括为：以确有疗效的中药复方为研究对象，以现代科学技术和传统中医药理论为技术支持，以该复方所治病证的药效响应为评价标准，以优化重组疗效更优的新复方为研究目的。

Ever since our world has been a world, native forests have been indiscriminately exploited by man.

自从我们的世界一直是世界原生森林被任意剥削人。