二次曲线

By analyzing phases velocity profiles and resistance lawv resulted from gas slug in the pipe center,the condition that the secondary flow occurs,phases velocity profiles,formula of drag reduction and a curve of drag reduction have been obtained.

以流体力学基本方程为基础，通过对气体在管道中心形成段塞流的相速度分布和阻力规律分析，得到了二次流发生的条件、各相流体速度分布、减阻率关系式以及减阻率曲线。

Study on the optimal conditions of cellulase from termites The optimal pH when Cx from Reticulitermes flaviceps reacted with substrate sodium carboxymethylcellulose was between 5.0-7.4 and 5.0-6.2 when BG enzyme was reacted with substrate salicin, the relation between activities of enzymes and relevant pH values accorded with Quadratic models.

一、白蚁纤维素酶最适反应条件研究黄胸散白蚁 Reticulitermes flaviceps C_N酶与羧甲基纤维素钠(Carboxymethylcellulose sodium，CMC-Na)反应的最适pH值范围在5.0-7.4之间，BG酶与Salicin反应的最适pH值为5.0-6.2，2种酶的活性均与pH值符合二次项曲线模型。

This paper takes standard straight-cut gear parameterization modeling for instance, introduces the method which is based on development of MDT technology and MDT three – dimensional modeling technology. This research provides three – dimensional entity modeling of parts with precise curve outline. And it demonstrates a practical method for similar situations as well.

本文以标准直齿圆柱齿轮的参数化建模为例，论述了采用MDT的二次开发技术及其本身的三维建模技术建立这类具有精确的曲线轮廓的零部件的三维实体模型，也为其它类似的零部件的三维建模提供了一种切实可行方法。

Since the lengths of the line segments and the angles between line segments are treated as representation parameters, it is convenient to construct energy function and to deal with displacement and length constraints. Based on this advantage, a parametrical model for human body is proposed, which can easily produce human body models with different feature sizes. The above method is just suitable for polylines. Therefore, a generic deformation method for both discrete curves and surfaces is presented. The energy function is constructed by analyzing the relationship of the points before and after deformation. Together with the displacement constraints, the deformation problem is converted to a convex quadratic programming. A necessary condition for constraint points and a sufficient condition for the uniqueness of solution are given. The proposed method can be combined with skeleton-driven animation to control the deformation.

将线段长度与线段之间的角度作为表示参数，既有利于能量函数的构造，又便于处理位移约束和长度内蕴约束条件，利用这一优势，将其应用于三维人体的参数化建模，可以方便地产生具有不同特征尺寸参数的人体模型，由于这种方法只适用于折线变形，具有较大局限性，因此，本文进一步提出一种较通用的离散曲线曲面变形方法，通过分析变形前后的位置关系来构造能量函数，再加上位移约束条件，将变形问题转化为一个凸二次规划问题，并且给出了约束点应满足的必要条件及模型解唯一的充分条件，这种方法还可以与骨架驱动变形的思想相结合，能更好的控制变形。

Applying theories of Vector geometry and differential calculus, this paper aims to infer the internal force and geometry equations for curved beam, whose axis curve is parabola and being distributing-load.

目的 对形心轴线为二次抛物线形曲线梁的内力、几何方程进行理论分析与公式推导。

Sphere fitting method, conicoid fitting method and line scanning curve fitting method are used to approach system error for the first time. The effect on the measurement error of each method is also analyzed.

首次利用球面拟合法、二次曲面拟合法以及行扫描曲线拟合法去逼近系统误差，并分析了各种方法进行系统误差校正时对最终测量误差的影响。

Carrying out a fitting to curves between rising height of capillary water and time with various functions,it found that fitting effect was best with secondary polynome regression equations under the log coordinate.

对毛细水上升高度与时间关系试验曲线用各种函数进行了拟合，发现毛细水上升高度与时间过程在对数坐标下用二次多项式回归方程进行拟合效果最好。

The design of the dry-dock falling gate"s structure is researched, and integrates the disquisitions and analysis on the dynamic characteristics about dock gate, in order to make the cabin design more visualizing.(2) The emphasis of this paper is the influence of the water hole and gas hole in the tidal cabin and the influence of the drain of the air-operated cabin.(3) In this paper, the building method of the dry-dock falling gate"s parametric model is studied and the dynamic analysis is accomplished in ADAMS, furthermore, the rising-and-falling angle curve is drawn while the dry dock gate is rising and falling.(4) The paper is based on the apprehension of the past theories and researches about air-operated dry-dock falling gate, and is explicated by hydraulic rationales and rising-and-falling mechanical principles. This software is developed by inner programming language in ADAMS and VC. This design could shorten design cycle.

1研究了气控式干船坞卧倒门的结构设计，整合对卧倒门在海水中运动中的动力特性研究，使卧倒门的设计，特别使其舱格设计更具可视化；(2)重点讨论潮汐舱水孔气孔对卧倒门水上运动的影响，空气操作舱充排水对卧倒门运动的影响；(3)研究了气控式干船坞卧倒门仿真模型的参数化方法和过程，并在ADAMS中完成了系统的动力学分析，绘制出了卧倒门在起卧过程中的运动特性曲线；(4)通过对已有的气控式干船坞卧倒门的实验成果和成形理论的解读，在理解其起浮和卧倒机理基础上，应用VC和ADAMS二次开发语言进行设计软件开发，定制了友好的用户化中文人机交互界面，使设计人员可以方便快捷地对卧倒门门进行设计开发，缩短了设计周期。

Using the Visual-LISP language, the system software AutoCAD is developed secondary by editing the application program"The Calculation of Easement Curve", by which the route curve calculation can be combined with the curve diagramming, in order to simplify the complex calculation and to detect the calculation results with easy.

利用AutoLISP语言对系统软件AutoCAD进行二次开发，编制了&缓和曲线测设计算&等应用软件，使一系列的道路测设计算工作与作图相结合，使复杂的计算问题简单化，并易于检核。

Through practical application, this system can deal with the cutter tool path file of counters, groves, holes, curves and surfaces directly, not need to do second-managing.

通过实践验证，本系统能够直接处理轮廓、内槽、孔系、曲线及曲面的刀具路径文件，不需人工再做二次处理。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。