查询词典 in the presence of

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％。

The photodegradation of three phenols in different mediums was studied in the presence of divalent manganese ions.

通过对不同锰离子浓度下三种酚在三种不同介质中的光降解情况的研究，来确定水体中的锰离子对酚类有机物的光化学降解的影响。

In summary, to judge whether the content of lead alloy can be achieved in the corresponding duty exemption, First, we must judge whether lead in the presence of alloying elements such as alloy.

综上所述，要判断合金中的铅含量是否可以达到相应的豁免值，就要首先判断铅是否是作为合金元素存在于这些合金当中。

Using the flexibility of proteins, egg white albumin was pore-formed and heat-denatured in the presence of substrate template. BSA protein and herring sperm DNA were trasted by precipitation method in organic solvent.

利用蛋白质在水溶液中的柔性，分别采用热变性法对蛋清蛋白质进行生物印迹和沉淀法对BSA进行生物印迹，并在BSA印迹的基础上又印迹了鲱鱼精脱氧核糖核酸。

There is growing recognition that mineral structures can form and deform at much milder pressures and temperatures than their pure equilibrium phase diagram would suggest, when in contact with water or in the presence of anisotropic strain and stress ref.

正在增长这样的认识，矿物组织，在与水接触时，或在存在着各向异性应变和应力条件下，能够在它们纯净的平衡相图所建议的更温和的压力和温度下形成和变形〔参看文献143〕。

In multiple regression analysis in the presence of latewood percent, estimative efficience don't increase with the number of ...

所以，不能以树木常用测定性状如胸径、树高和年龄来预估胸高木材密度。

In this thesis, we propose a self-detecting algorithm for the nodes of a wireless sensor network to determine the event boundary in the presence of faulty nodes. The nodes exchange messages and execute the algorithm in parallel to determine whether they are located on the boundary of an event.

在这篇论文中，主要的目的是在一个无线感测网路环境下，如果当事件发生时，每一个感测节点如何透过单纯的资料交换和平行演算法来达到自我侦测并且判断出本身是否位於事件的边缘。

In this paper, we present a semi-supervised algorithm to learn Gaussian process classifiers, which is combined with nonparametric semi-supervised kernels in the presence of unlabeled data.

摘要提出了一种半监督算法用于学习高斯过程分类器，其通过结合非参数的半监督核向分类器提供未标记数据信息。

Methods: In the presence of hydrochloric acid or nitric acid, geranyl sulfone was prepared from geraniol in isopropyl alcohol or THF under reflux conditions for 18 h or 28 h, respectively.

以异丙醇或THF为溶剂，盐酸或硝酸为催化剂，香叶醇与苯亚磺酸钠回流反应18或28 h得香叶基砜。

A process in which naphthas are converted to high-octane aromatics in the presence of hydrogen and a catalyst under pressure and heat.

临氢重整在高温高压下，在氢和催化剂的作用下石油精转化为高辛烷值的芳烃的过程

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。