查询词典 helices

The total molecular optical rotatory power depends on the algebraic sum of rotations of all helices existed in the molecular structure .

化合物的总旋光方向是由分子结构中所有螺旋旋光度的代数和所决定。

X-ray determining indicates that xanthan gum has a antiparallel double helices conformation,on which its special properties of water solution base.

经 X －射线测定，黄原胶呈反向双螺旋机构，并可形成具有网状结构的次生构造。

Discusses algebraically and geometrically the properties of the ruled surfaces in the Euclidean three-space, especially, the principal normal surfaces on which there are some special curves, such as Mannheim curves, Bertrand curves and general helices.

在三维欧氏空间中，作为特殊曲线，Mannheim曲线、Bertrand曲线以及一般螺线具有良好的几何和代数性质。讨论了三维欧氏空间中特殊曲线的主法线曲面。

In this paper, a "rigid bar relative movement model" was established to illustrate the traces of the helices in wire ropes. The angular speed of a moving particle of the model was relatives to curvature tensor to derive the curvature components and torsion of helices in multi-layer wire ropes. According to long and thin rod theory of Love and Yen-Chen's theoretical model considered the contact force and frictional force, the force-deformation or force-strain relative of wire in curved wire ropes subjected axial force is derived from the curvature components and curvature increment.

本研究改以刚杆相对运动模型，直接描述钢索中钢绞线轨迹，并且透过角速度类比曲率张量之概念，推导圆弧型多层钢索内部之钢铰线之曲率分量与扭率；之后再依据Love的细长杆理论，辅以Yen-Chen在考虑接触力及摩擦力下所修正之理论模型，以曲率及曲率增量来探讨圆弧型钢索受静态荷重作用下，钢绞线之受力与变形或应变关系。

What is the average length of alpha helices found in crystal structures of globular proteins?

请问在球蛋白晶体结构中alpha螺旋与beta平板的平均长度各为何？

The helices are held to each other by hydrophobic interaction, as both are lined with leucine amino acids.

两个螺旋通过疏水相互作用而保持在一起，因为两者都具有排布成一条线的亮氨酸。

By the definition of Darboux type vector and rectifying Darboux type vector ,we constructed the rectifying type developable surfaces and Darboux type developable surfaces and tangential Darboux type developable surfaces ,and study these three developable surfaces relationship with Minkowski slant helices and Minkowski conical geodesic curves. Bying applying the singularity theoerical knowledge, We give a classification of special developable surfaces under the condition of the existence of such a special curve as geodesic.

通过定义三维Minkowski空间中的达布型向量以及修正达布型向量，构造出三维Minkowski空间中的三类可展曲面，即修正型可展曲面、达布型可展曲面和切达布型可展曲面，研究Minkowski斜螺线和Minkowski锥面测地线这两种特殊曲线和这些曲面的关系，并研究Minkowski斜螺线和Minkowski锥面测地线作为这些曲面的测地线的条件下，运用奇点理论的知识，对这三种可展曲面进行奇点分类。

Many groups have focused on a particularly stable structure composed of alpha helices.

很多组织已经开始关注由αhelices组成的一个特别稳定的结构。

Thus, the statistics that there are more shortest α-helices than 3(subscript 10)-helices of the same length can be understood.

因而，在同样长度下α-螺旋比3(下标 10)-螺旋多的统计结果能够被理解。

However,there have been no papers which have investigated Minkowski and Minkowski slant helices and Minkowski conical geodesic curves so far as.In this paper,our major study is to give the definition of Minkowski general helix and Minkowski slant helices and Minkowski conical geodesic curves in indicators 1 in pseudo-Euclidean three-space (that is, three-dimensional Minkowski space), and study the definition of equivalence Minkowski general helix, By considering geometric invariants of these space curves, we can estimate the order of contact with those special curves for general space curves.

本篇文章主要研究在指标数为1的3维伪欧氏空间(即三维Minkowski空间)中，我们给出Minkowski一般螺线、Minkowski斜螺线和Minkowski锥面测地线的定义，研究Minkowski一般螺线的等价定义，给出Minkowski斜螺线和Minkowski锥面测地线作为三维Minkowski空间中的特殊曲线所特有的性质，并通过考虑三维Minkowski空间曲线的几何不变量，估计Minkowski斜螺线和Minkowski锥面测地线这两种特殊曲线和一般Minkowski空间曲线切触的阶数。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。