介质

The reaction of polyfluoroalkyl iodides with 4-pentenoic acids in the presence of sodium dithionite at room temperature in aqueous acetonitrile solution [CH〓CN: H〓O=3: 1 ] to gave the corresponding adducts, the latter could form γ-lactones 31～51 in the same medium in 62～92％ yield.

室温下，在乙腈/水[3：1]的介质中，多氟烷基碘化物在连二亚硫酸钠的存在下与4-戊烯酸及其在2或3位上具有取代基团的衍生物进行反应，反应2～5h，起先生成两者的加成物，该加成物无需分离，在同一介质中，可进一步反应得到相应的多氟烷基取代的γ-丁内酯31～51，产率62％～92％。

It is possible to simultaneously examine the polarity and viscosity of medium when DNP is used as a fluorescence probe.

这一性质，再加上激基缔合物峰与单体峰强度比反映介质粘度，使DNP成为能同时探测介质极性和粘度的荧光探针。

First,from the constitutive relation and the transform relation connecting time domain and frequency domain,the differential equations of double negative material are obtained.

由双负介质的本构关系出发，利用时频转换关系，推导出了描述双负介质中场与流的微分方程组。

Using the transform relation connecting time domain and frequency domain and the constitutive relation,the differential equations of double negative material is obtained.

由双负介质的本构关系出发，利用时频转换关系，推导出了描述双负介质中电磁场与电磁流的微分方程组。

According to the boundary relations of the electromagnetic field, and based on the phenomena of double refraction and double reflection in crystals, the reflectivity and transmissivity are deduced at boundary when an extraordinary beam is incident from an isotropic medium upon a crystal or from a crystal to an isotropic medium with optical ax.

为分析非常偏振光在晶体表面的能量损耗，给出一种求解反射率和透射率的方法，即根据电磁场的边值关系以及晶体的双折射和双反射现象，求解晶体光轴在入射面内时，非常偏振光从各向同性介质入射到晶体和从晶体出射到各向同性介质两种情况的反射率和透射率的方法，并给出反射率和透射率的解析解，同时得到对于晶体光轴在入射面内的情况，光轴的取向对非常偏振光反射率的大小几乎没有影响，但对产生全反射的临界角θc影响较大的结论。

Circulation of cooling medium in closed system is realized through density difference between mixture of gas / liquid in ascending tube and liquid in downcomer, which is defined as natural cycling, and known as Self Circulation for short.

密闭系统内的冷却介质依靠下降管的液态与上升管中汽/液混合物之间的密度差实现冷却介质循环的过程，定义为自然循环，简称自循环。

Sow seeds of Drosera spatulata on the surface of your medium of choice. Finely chopped live sphagnum moss over long fibered sphagnum moss or CP mix works very well but the moss can overgrow the plants.

将小毛毡苔的种子播在你选择的介质表面，切成小段的活水苔或混合介质都很适合，但是活水苔可能会长得比植株还高。

Corrosion performance of olive green film on LY12 Al alloy, prepared electrolytically in 0.2 mol/L NaOH at room temperature, is evaluated by electrochemical techniques including dynamical potential anodic polarization curve and polarization resistance.

在弱碱性介质中阳极氧化制备LY12铝合金着色膜，用动电位扫描法极化曲线和极化电阻电化学测试技术方法研究了着色膜在中性和酸性介质中的耐蚀性能以及时效腐蚀行为。

The refractive energy, with the electron cloud conductor.

论文摘要：研究了光的磁场在光与介质相互作用中的行为，建立了电子云导体模型：介质中一个电子的电子云可以看作一个微小导体，光变化的磁场与电子云导体间的电磁感应作用导致光与电子云导体之间能量交换。

They are the same for electronic media and paper.

对于电子介质和纸介质要求是一样的。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。