圆的

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。

Calculated area of circle, a numerical input, press the button will get a corresponding area of circle.

详细说明：计算圆面积，输入一个数值，按按钮就会得到相应的圆面积。

Because any reports on the active control of rotating disk haven't be seen in China up to now, and this experiment research is important, so the complete set of active control system of rotating disk are built independently. The push-pull type electromagnet is applied to control the vibration of the circular disk. The power amplifier circuit that can respond to wide scope in frequency from DC to AC is designed by improving the existing circuit. The sensor signal is first low-pass filtered, then the proportional control plus the differential control circuit easy used in practice are applied to finish the more effective control. The electromagnetism shield is used as possible to decrease the signal disturbance from the electromagnet to eddy sensor.

考虑到目前国内尚未见到有关旋转圆盘振动主动控制的相关报导以及实验的重要性，自行设计制作了一整套旋转圆盘振动主动控制系统：提出并采用推拉型电磁作动器来控制圆盘的振动；在改进现有电路的基础上，自行设计了具有较理想特性的驱动电磁作动器的功率放大器；根据实际控制环境的特点，设计了先进行低通滤波，再采用比例和实用的近似微分电路构成的控制器，并采用了电磁屏蔽来减小电磁铁对传感器的干扰，以实现更有效的控制。

Our company specializes in the creation of the valve handwheel, handle, bevel gear, worm gear boxes, valve stem, nuts and various valve accessories enterprise can also be in accordance with customer requirements, order a variety of different specifications of hexagonal, square heart, round hole Size of hand wheel of the Company since its inception has been committed to product innovation, and constantly develop new products, our customer-centered and quality as its core business philosophy, in order for the company's products to better serve the society serve the public, the company's strict production management system, continuous introduction of new technologies, new materials, new techniques, and is equipped with a set of complete machining equipment and sophisticated testing equipment to create the link axis hand wheel, hand wheel Fang, keyway hand round, hexagonal hand wheel, lever ball valve, butterfly valve handle, valve bevel gear, worm gear box, is the Quartet SL101-F type, cone Quartet SL101-Z type, is the Quartet SL104-F type, flower type is SL105 Quartet , cone Quartet SL-104-Z-type, hexagonal SL104-L-type, hexagonal SL101-L type, round type keyway SL101, SL104 keyway circular type, is the six-party type SL102, SL101-J-type keyway, keyway SL102-J-type , SL103-J-type keyway, keyway SB101-J-type, the second generation of new hand wheel, BA series bevel gear, WQDX3, QDX3, QDS3-S, QDX3-G, XQDX3, QDX3-CF, FQDX3, SQDX3 part series back to transformation of the valve device manually, QDX3-C, QDX3-D series valve electric part of the transition back to devices, valve cover series, bearing gland series, the electric-type bearing cap, with a round open cap, sealing the Block series, hand - hard hat round shields hexagonal locking nut series of the Company follow the "survive on quality, reputation and development" business philosophy and the integrity, service, communicate, progress, development.

本公司自创建以来，就一直致力于产品的技术创新，不断开发新产品，秉承以客户为中心，以质量为核心的经营理念，为使公司的产品能更好的服务于社会、服务于大众，公司实行严格的生产管理制度，不断采用新技术，新材料，新工艺，并配有一整套完善的机械加工设备和检测设备制造出精良的连轴手轮，方心手轮，键槽手轮，六角手轮，球阀手柄，蝶阀手柄，阀门伞齿轮，蜗轮箱，正四方SL101-F型，锥四方SL101-Z型，正四方SL104-F型，正四方SL105花型，锥四方SL-104-Z型，六角SL104-L型，六角SL101-L型，圆型键槽SL101型，圆型键槽SL104型，正六方SL102型，键槽SL101-J型，键槽SL102-J型，键槽SL103-J型，键槽SB101-J型，第二代新型手轮，BA系列伞齿轮，WQDX3，QDX3，QDS3-S，QDX3-G，XQDX3，QDX3-CF ，FQDX3，SQDX3系列部份回转型阀门手动装置，QDX3-C，QDX3-D系列部份回转型阀门电动装置，阀瓣盖系列，轴承压盖系列，电动型轴承压盖，圆开帽，上密封座系列，手轮护罩拼帽系列六角锁紧螺母系列本公司遵循&以质量求生存，以信誉求发展&的经营理念和诚信，服务，交流，进步，开拓。

With minimizing the move distance as the optimization objective, the circular curve radius and circle center coordinate were then optimized, the transition curve length, the move distance of each measured points, the mileages and the coordinates of the feature points and so on were further computed.

首先利用坐标法计算各测点的坐标，再计算正矢，然后根据正矢的变化规律选定圆曲线上的测点，用最小二乘法拟合出既有线圆曲线的半径和圆心坐标，并以拨正量最小为优化目标，优化圆曲线半径及圆心，进而计算出缓和曲线的长度、各测点的拨正量、特征点的里程和坐标等。

Screws, bolts, or nuts without washers must be loaded against a test plate with a minimum diameter clearance hole equal to the nominal thread size plus 0.50mm for fasteners M6 (1/4 inch) and smaller, and plus 1.0mm for larger diameters.

无垫圈的螺钉、螺栓、或螺母应被装夹到具有较小孔径的通孔的试验圆板上进行试验，对于≤M6 (1/4 inch)的紧固件，试验圆板的孔径为公称螺纹直径加上0.50mm，对于＞M6 (1/4 inch)的紧固件，试验圆板的孔径为公称螺纹直径加上1.0mm 。

In this paper, we proved that there exists only one contact point between a pair of non-circular gears working under the designed pitch curves when they are manufactured by involute cylindrical gear cutter in numeric control slotting machine. Under this manufacturing condition, the pair of non-circular gears can mesh accurately.

证明了采用渐开线圆柱齿轮刀具在数控插齿机上加工的1对非圆齿轮副传动时，在其按设计的已知节曲线工作时，两非圆齿轮副的齿廓具有单一的接触点，即能保证正确的啮合关系，为深入分析非圆齿轮副的传动机理提供了前提。

In order to roll round billets with accurate roughing shapes by a three-high roughing mill and stabilize production, a flexible pass design method was used to optimize the traditional conjugate pass through the distortion design of the bottom, side wall and pressure difference of the pass, realizing the application of the conjugate round pass on the three-roll mill.

为轧制料形尺寸准确的圆料、稳定生产，采用变通孔型设计方法对共轭孔型进行优化设计，通过对共轭孔型槽底、侧壁、压力差的变形设计，实现了共轭圆孔型在三辊粗轧机上的应用，轧槽咬钢顺利，成品圆料容易控制，完全满足后续工序的要求，同时减小了轧线的轧制事故，单套轧辊的轧制量可提高60%以上，取得了良好的经济效益。

Beijing presses with a strong technical strength, well-processing equipment, advanced production technology and a rigorous quality assurance and improvement of mechanisms to facilitate the after-sales service, so that we mesh bags of vegetables round looms, round wire rope course Sila Si machine, Sila Si-Chen Shui-bian, winding machines, eight shuttle round loom large, complex machines, printing presses, blown film machines, plastic woven bags and other bag of complete sets of equipment to the successful domestic and foreign markets.

京开塑机具有雄厚的技术实力，精良的加工设备，先进的生产工艺，并有严谨的质量保证和完善方便的售后服务机制，使我们的蔬菜网眼袋圆织机、绳网丝圆丝拉丝机、扁丝拉丝机、收卷机、大八梭圆织机、复合机、印刷机、吹膜机、制袋机等塑料编织袋成套设备成功走向国内外市场。

Themapping function sequences including circular cutouts and elliptical cutouts aregiven in this chapter.

然后为方便地满足圆柱壳大开孔的边界条件，通过复变函数方法中的用来求解多边形映射问题的Schwarz-Christoffel积分表达式，将圆柱壳展开面上的非圆非椭的开孔边界曲线保角映射成为单位圆，给出了在不同开孔率情况下的关于圆孔和椭圆孔的保角映射函数的具体形式。

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。