分辨

1H NMR spectroscopic analysis of aromatic protons combined with theoretical analysis of molecular structures proved the existence of two rotational isomers at 300 K, as well as a rapid interconversion equilibrium at 330 K for both compounds Ⅰ and Ⅱ. However, only one conformer exists for compound Ⅲ and puerarin containing 7-phenolic hydroxyl instead of propyl in A-ring as the case of compounds Ⅰ and Ⅱ. Based on UV-Visible absorption data of neutral and basic solutions, and on the density function calculations, the 7-phenolic hydroxyl group in A-ring was found to be more acidic than the 4'-phenolic hydroxyl group in B-ring. The mechanism of derivation reaction and the structure-reactivity relationship of puerarin as an antioxidant were further discussed.

其中7-丙基葛根素Ⅱ属于新型取代衍生物；变温1H NMR和理论计算结果表明，在300 K时，葛根素和4'-丙基葛根素以单一构型存在；而7，4'-二丙基葛根素和7-丙基葛根素则存在两种核磁可分辨的旋转异构体，当温度升至330 K时，两种异构体可以相互转化；通过对比分析葛根素及其衍生物脱质子产物的紫外可见吸收光谱并结合理论计算，确定了A环上7位酚羟基比B环上4'位酚羟基先脱去质子，并由此进一步阐明了葛根素衍生化反应机理以及在抗氧化作用中可能的活性位点和结构活性关系。

Influence of conglutination of CsI∶Na columns on the resolution properties.

晶柱粘连对CsI∶Na转换屏分辨特性的影响。

The first kind of operator and Walsh function transformation were conjointly used to enhance the vertical resolving power of the old well logs and improve its capability in reservoir heterogeneity identification.

将第一类算子问题与沃尔什函数变化方法相结合，提高老井测井曲线的纵向分辨率，进而提升常规测井曲线对储层非均质性的分辨能力。

The oscillator has no connection with any oher component and it just brings about vibartion through the delay of circuit.

与非门构成的可控环形振荡器由于没有外接任何元件，它依靠门电路自身的延迟时间而形成振荡，因此，其振荡频率很高，为提高抢答组之间的分辨时间提供了条件。

Integrating with the continuous level of detail of geometry mesh, we present an criteria for selecting an appropriate node on the texture the quadtree, and rendering the mesh with the corresponding quadtree texture.

纹理组织方式有效地匹配于地形几何的连续层次多分辨细节模型，提出了纹理四叉树的多分辨率选取策略，并从纹理结点出发，绘制几何网格。

In first part,The Theory and Simulation on Reconstruction Algorithms,webuild a well-defined mathematical model for OCT,on which we prove more than 10theorems,analyze and answer a series of significant questions about OCTreconstruction,from existence, uniqueness,continuousness,stability to sampling,resolution,ill-posedness and accuracy.

在上篇重建算法的理论与实践中，我们将OCT抽象为基于n维Radon变换的数学模型，从而分析、讨论、回答了从存在性、唯一性、连续性、稳定件到采样条件、分辨能力以及病态特件和重建精度等一系列在理论和了OCT的重建理论体系。

Cokane's features are contort ed by an air of judicial consideration; but he says nothing

高坎显出一副由于分辨是非而愁眉苦脸的样子，但他却一言不发。

It can be difficult to distinguish the Tiger Snake from the Copperhead since sizes, habitat preferences and behaviour overlap somewhat.

也难以分辨老虎从怀中copperhead由于面积有所重叠境偏好和行为。

Here and there in the blue distance, to right and to left of the copse and the road, could be seen smoking camp-fires and indistinct masses of our troops and the enemy's.

在那黛青色的远方，在森林和大路的两旁，好些地方都可以看见冒烟的篝火和分辨不清的敌我双方的战士。

Most of us can't tell our secant from our cotangent.

我们中的大多数不能分辨正切余切。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。