精度

The paper designs a scanning unit for immersion ultrasonic C scan system,in which the designing mechanism and structure are illuminated in detail,and indicates that the key factor for precision is the error of the lead screw.

设计了一种超声 C扫描检测系统扫描机构，详细介绍了该扫描机构的设计原理及结构实现，并对该机构的定位精度进行了分析，指出在该机构中，影响定位精度的关键因素是丝杠的误差。

During of the work, a mount of experiment was done for verifying the Localizers accuracy, which is a good result under the present conditions of Lab.

在研制过程中进行了大量的实验验证系统精度，在现有的实验室条件下获得相对较高的精度目标。

According to the wire electrode on the trajectory of the different forms of control, WEDM can be divided into three types:* is a copy-control, cutting their lines in advance to create the shape of the workpiece and the same mode *, When the rough machining parts and die at the same time * Clamping in the machine tool table, in the process of cutting wire electrode tightly * close to the edge of model for mobile track, thus cutting out the model * with the same shape and precision to work; another One is the optical tracking control, the cutting in line before the first parts in accordance with drawings by a certain ratio of enlarge depicts an electro-optical tracking maps, drawings will be processed when the machine electro-optical tracking placed on the stage, followed on the stage The first photo has to follow the ink line graphics track movement, and then through the use of electrical, mechanical linkage to control the machine tool table work together with the relative electrode wire Xiang Sixing do sports in order to cut out the pattern and shape of the workpiece to the same; a re - Is a digital process control, advanced digital automatic control technology, machine-driven process in accordance with the geometry of the workpiece before the parameters of good pre-processing CNC automatic completion of the processing, production do not look like without drawing board also plans to enlarge, in front of more than two Control in the form of higher precision processing and broad scope of application, at home and abroad for more than 95% of WEDM have been using digital technology.

根据对电极丝运动轨迹的控制形式不同，电火花线切割机床又可分为三种：一种是*模仿形控制，其在进行线切割加工前，预先制造出与工件形状相同的*模，加工时把工件毛坯和*模同时装夹在机床工作台上，在切割过程中电极丝紧紧地贴着*模边缘作轨迹移动，从而切割出与*模形状和精度相同的工件来；另一种是光电跟踪控制，其在进行线切割加工前，先根据零件图样按一定放大比例描绘出一张光电跟踪图，加工时将图样置于机床的光电跟踪台上，跟踪台上的光电头始终追随墨线图形的轨迹运动，再借助于电气、机械的联动，控制机床工作台连同工件相对电极丝做相似形的运动，从而切割出与图样形状相同的工件来；再一种是数字程序控制，采用先进的数字化自动控制技术，驱动机床按照加工前根据工件几何形状参数预先编制好的数控加工程序自动完成加工，不需要制作模样板也无需绘制放大图，比前面两种控制形式具有更高的加工精度和广阔的应用范围，目前国内外95％以上的电火花线切割机床都已采用数控化。

This article puts forward a kind of new open extrusion technology of precision reducing diameter with mandril.

为了提高传动轴临界转速，要求提高传动轴管两端口尺寸精度，若采用传统的无芯棒缩径工艺已无法保证制造精度。

Though ultra precision lathe developed by HIT have higher manufacturing accuracy, it has no ability to compensate for errors. If on the foundation of old CNC system, a valid error compensation system were added, the manufacturing accuracy of the lathe would be improved largely, at the same time theory and methods used in this paper can be applied to other machine too1s, So the study in this paper have both the significant theoretical meanings and the practical value.

哈工大研制的超精密车床虽然具有相当高的加工精度，但是其数控系统本身不具有误差补偿功能，如果在原数控系统的基础上，增加误差补偿控制系统，该车床的加工精度将有大幅度提高，同时文中所用理论和方法也适用于其它机床，因此本文的研究具有重要的理论意义和应用价值。

However, because the measuring process is influenced by many factors, it is difficult to improve the accuracy of dynamic measurement. It is the focus of the measurers and the designers all through the ages. Thus, the research on dynamic error and accuracy theory is always heavily concerned.

由于动态测量的影响因素较多，如何提高其测量精度，一直是工程测量与仪器设计人员关注的重点，因而，对动态误差与精度理论的研究也历来受到人们的重视。

The main product has:Cold water machine of high accuracy,High accuracy mold temperature control machine,Control system of hot oil temperature,The machine side smashes to recover system,Divided by wet dry add the integral whole the machine,The concentration provides the cold or caloric system,The concentration provides the raw material system,The plastics mix withes the machine and Waste plastics recycring and reprocessing.

主要产品有：高精度冷水机，高精度模温机，热油温控系统，加料、粉碎、回收生产系统，除湿结晶干燥系统，集中供冷、供热系统，集中供料系统，塑料混合机等成型及回收专业生产设备。始终与用户保持紧密联系与合作，致力于领域内的深层探索和满足用户的实际需求。Sairs立足于不仅制造销售机器，而且提供最科学化，便捷化，合理化的技术。积极参于工程塑料时代生产技术的革新，与用户一起思考，共同分享成功的未来！

The above problems are studied in this thesis. First, the implicit NND scheme with mix flux splitting method proposed by Zhang Hanxin that is first order accurate in time and second order in space is modified. The modified scheme keeps the characteristics of fast convergence and is second order accurate both in time and space. It can be capable of simulating the unsteacly flow. Second, the topological method founded by Zhang Hanxin is improved to study the characteristics of vortex near the singular point on its axis and the cross streamlines on the longitudinal section passing the vortex axis. On the basis of topological results, a program which visualises numerical results is made out. It can help us analyse the characteristics of vortex motion.

本文对上述问题做了研究：第一，在数值模拟方面，借助于张涵信提出的NND算法和混合通量法，我们将他建立的时间为一阶、空间为二阶精度的快速隐式算法推广为时间和空间均为二阶精度的算法，这样做保留了原格式收敛快的特点，而且能适用于真实的非定常流态的计算；第二，将张涵信的拓扑分析方法加以推广，研究了涡轴附近及破裂点邻域内流场的空间特征，并以这些拓扑分析结果为指导，研制了一套显示计算结果的软件，这一软件能很好地帮助我们分析流场的计算结果和旋涡演变的特征。

The theoretical analysis and experiments show that high overlay accuracy can be realized with the mark-based overlay method in SPM lithography, and the overlay accuracy can be quantitatively measured by the overlay metrology with verniers. The overlay method could be widely applied in the hybrid lithography with SPM.

理论分析与实验研究证明，在利用SPM的加工技术中，基于标记的场套刻对准方法能够实现高精度的套刻加工，通过游标检测法能够实现对于套刻对准精度的定量表征，本方法在利用SPM的混合加工技术中具有广阔的应用前景。

The definition of generator angle is proposed in this paper. A new method to deduce generator angle by using rotor rotation signal is illustrated, which compares the phase difference between GPS timing pulse and RRS. Using only mechanical signal, the technique unfreezes limitation of zero-cross of generator terminal voltage during transient process. Automatic correction of initial generator angle is also proposed .

本文介绍了同步发电机绝对转子角的定义，提出了一种测量绝对转子角，进而获得高精度的相对转子角的方法；此方法不使用机端电压过零整形脉冲，而是将机组键相脉冲与GPS 定时脉冲比相，并能够自动整定初始位置角，因此，测量结果不受发电机运行状态的影响，能够在各种运行方式和扰动情况下获取高精度的绝对转子角。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。