查询词典 geometrical element

Configurational isomerism is then due to the presence in the molecule of one or more dissymmetric centres ,in the simplest case asymmetric carbon atoms ,each of which can have and absolute configuration; and ,or ,to the presence of double blonds which can give cis- and trans-geometrical isomers .

构型异构是由于分子中存在一个或一个以上的不对称中心，在最简单的情况下是不对称碳原子，每个不对称碳原子的绝对构型是和；或者，如果存在双键的话，那么将给出顺式和反式几何异构体。

Accoring to the polar theory of conic section, the characteristics of geometrical graphics concerning the conic section is discussed from following three aspects:the conbination of Point and line, harmony of point range and pencil of line , trace of point and enveloping of straight line.

本文根据二次曲线的配极理论，从点、线的结合性，点列和线束的调和性，点的轨迹和直线的包络三方面研究与二次曲线有关的几何图形的性质。

Because it emphasizes on algebraic method, geometric intuition are lose. Especially in the unit of conic section, although "the unity of geometrical material and algebraic symbol "is the teaching objective of text books, but according to the material of text books, it is difficult for students to arrive.

本文首先试著分析目前高中数学教科书中，对於几何部份的教材编写上，由於编写者的意识型态不同，理念不同，数学教师对教科书的诠释就会因此而有不同，因而造成目前高中几何教学著重在代数方程式上的一些问题。

This article takes the teaching of conic sections as an example. By designing worksheets, teachers can introduce the historical material about conic sections to students. By way of using Apollonius' definition of parabola, ellipse and hyperbola, teachers can introduce the geometric aspect of "conic section" to students. By using the concept of " latus rectum " in Conics , we can connect "conic sections"-- representation of geometrical aspect, with "the equation of conic sections"-- representation of algebraic aspect to improving insufficiency of text books.

同时本文也试著从历史文本中寻找材料，简单举例说明数学教师可以如何应用这些史料在几何单元教学上，例如三角函数的正余弦定理，最后再以圆锥曲线的正焦弦为例，说明如何利用数学史料於此单元的教学，尤其是阿波罗尼斯的《锥线论》中对圆锥曲线的3个命题，将此3个命题的内容与意涵，尤其是正焦弦在圆锥曲线的几何意义上所扮演的角色，将其适当地融入教学中，将可使学生真正学习圆锥曲线的几何知识，而不再只是代数形式的几何知识。

According to the geometrical principle of conical milling cutter with equal helix angle, a new process of rough machining of conical milling cutter with equal helix angle on universal milling machine by using additive equipment is presented.

根据等螺旋锥铣刀几何原理，提出一种借助附加装置在万能铣床上进行等螺旋角锥铣刀粗加工工艺，介绍了该方法加工锥铣刀时工作铣刀的运动方程；给出了附加装置的设计原理，通过对用此方法加工出的铣刀参数进行测试，证明了这种方法的可行性和实用性。

The horizontal universal milling machine technological transformation based on Mitsubishi PLC;2. Analysis of some important points for makinghelical gear on universal milling machine ;3. According to the geometrical principle of conical milling cutter with equal helix angle, a new process of rough machining of conical milling cutter with equal helix angle on universal milling machine by using additive equipment is presented.

根据等螺旋锥铣刀几何原理，提出一种借助附加装置在万能铣床上进行等螺旋角锥铣刀粗加工工艺，介绍了该方法加工锥铣刀时工作铣刀的运动方程；给出了附加装置的设计原理，通过对用此方法加工出的铣刀参数进行测试，证明了这种方法的可行性和实用性。

In the teaching of central field, we should pay attention to turning the relative motion of two - body into one dimentuonal radial motion by introducing two physical concepts of reduced mass and effective potential energy, and we should also pay attention that the area law is the geometrical description of the conservation of angular momentum in the central field.

在有心力场教学中，应着重强调指出：通过引入折合质量和有效势能这两个物理量，把二体相对运动问题转化为单体沿径向的一维运动问题；以及面积定律是质心在有心力场中角动量守恒的几何描述。

In order to prevent the deformation of the physical domain, the geometrical consistency conditions were used.

为提高紊流计算精度，对κ-ε模型结合壁面函数法同LVEL、Baldwin-Lomax这两种代数紊流模型进行了比较。

It proposed a hybrid state based control method for stabilizing an unstable periodic orbit by controlling controllable continuous limit processign time, referring to the geometrical property of the system behavior and employing sliding-mode approach.

提出了三个Buffers切换到达系统不稳定周期轨道的一种基于混合状态的镇定控制方法。

Compared with smooth tube,micro-fin tube has more geometrical parameters that influence heat transfer to different extent.Many scholars has done much work on it,but some research results are different or even contradictable.

相对于光管，微肋管的结构参数相对较多，这些结构参数的变化会不同程度地影响微肋管的换热能力，国内外的很多学者进行了研究，但结论相差较大，甚至完全相反。

You can snipe the second and third union leaders from this position.

您可以鹬第二和第三工会领袖从这一立场出发。

Aiming at the currently shortage of XML streams quality detecting, this paper proposes a new forecasting method of XML streams quality by least squares support vector machines, which is used the method of XML keys' vector matrix as windows, and vector product wavelet transform to multilevel decompose and refactor the XML streams series, that can fulfill real-time checking demand of XML quality, and ensure constraint, consist- ency and integrality. For even more adapting net load, it proposes a control strategy by weight and adaptive adjustment to ensure XML streams quality.

针对当前XML数据流质量检测存在的不足，提出构建XML键的矢量矩阵作为窗口，利用矢量积小波变换多级分解与重构XML数据流，再结合最小二乘支持向量机对XML数据流质量进行预测的一种方法，满足XML数据流质量重构时实时检测的要求，保证XML数据的约束性、一致性与完整性；为了更好的适应网络负载，采取加权与自适应窗口调整等调度策略充分保证XML数据流的质量检测。