化学

The effect of different coagulants and catalysts on the removal of organic contaminants in the wastewater was tested and the optimal coagulant and catalyst were determined.

实验了多种化学混凝剂及多种催化剂对废水中有机污染物去除率的影响，选取了最佳催化剂和最佳化学混凝剂。

The teaching theories of using construction, the theories of information processes , the study theories of person ism, according to the essence that the student cognizes the regulation and knows to the thing, studied the chemistry web-based instruction mode and the chemistry network teaching system course designs of the high school in actual teaching work.

运用建构主义教学理论、信息加工理论、人本主义学习理论，根据学生认知规律和对事物认识的本质，在实际教学工作中研究了中学化学网络教学模式和化学网络教学系统课程设计。

In this thesis, two chemical structural models were constructed based on several structure parameters derived from FTIR and 13C NMR data, which were processed by curve-fitting and curve-resolved. Modified models were obtained by simulation oftheir molecular vibration spectra using Cerius 4.6/IR module andthe structural parameters from 13C NMR. Potential energy, bondenergy and non-bond energy of the minimum-energy conformations of coal macromolecules were calculated by molecular mechanics calculation and molecular dynamics simulation. These results demonstrate the importance of hydrogen bonding and van der Waals interactions in the formation and stabilization of coal macromolecular structure, and a strongest tendency of hydrogen bonding interactions to increase with the coal molecules but the Coulombs force.

本文运用煤结构的傅立叶红外光谱和固体核磁共振碳谱~(13C NMR测试方法所得的结果，经过谱图分峰、分析，计算出若干表征煤大分子结构参数，并综合前人的经验和共识，利用计算机分子绘图软件系统构建了表征两种褐煤的化学结构模型，在Cerius~2 4.6／IR模块中计算了分子振动红外光谱，同时结合碳谱所计算的分子结构参数拟合、修正了该结构模型，得到了能表征这两种煤样的分子结构模型，作为用分子动力学模拟和量子化学计算的初始结构模型。

The quantitative relationship between isomer shift, refractive index and chemical bond parameters were established. The calculated results indicated that the change of crystal parameters and bond length will alter the covalency of chemical bond and peripheral electron density of Fe2+ nuclear, which in turn leads to the change of the isomer shift and refractive index.

根据计算结果发现，晶胞参数及化学键长的变化引起化学键共价性、Fe2+核附近电子云密度的变化等，最终导致同质异能位移的改变，计算结果与实验数据之间较好的一致性验证了此理论的准确性和普适性。

For years, scientists have been finding that endocrine disrupters like BPA can impair the reproductive organs of rats and mice, reduce sperm counts in rats, and bring about changes in tissue that resemble early-stage breast cancer, among other effects... Normal wear-and-tear and cleaning of polycarbonate plastic bottles in a dishwasher, Hunt says, could cause the chemical to leach, and the amount of leaching increases as the plastic ages and is degraded by use.

多年以来，科学家们已经发，像BPA这类内分泌干扰素可以损害家鼠和野生老鼠的生殖器官，降低精子质量，引起某些组织的变异导致早期乳腺癌，甚至还有其他一些不利影响……聚碳酸酯塑料瓶的日常磨损和在洗碗机中的清洗，会导致化学物质的滤出，Hunt博士说，而且随着他们的老话和使用磨损，滤出的化学物质会越来越多。

This dissertation focus on rutiles, apatites epidotes and vein minerals from CCSD drill core and outcrops of Sulu-Dabie UHPM rocks, by detailed study of petrography, petro-chemistry, and mineral-chemistry, the implication of these minerals to UHPM and continental subduction-exhumation were discussed.

大别地表超高压变质岩中的这些副矿物和脉体矿物为主要研究对象，通过详细的岩相学、岩石化学、矿物化学等研究，对这些副矿物在超高压变质作用及大陆深俯冲—折返过程的指示意义进行了较为深入的探讨，在以下几个方面取得新的认识：1。

Etchant chemicals: Etchant chemical components, it is not the same as the etching rate, etching coefficient.

蚀刻液的化学身分的构不败：蚀刻液的化学组分不不对别，其蚀刻速度不离不不异，蚀刻系数也不不对别。

The study of host-guest chemistry based on crown ethers and secondary dialkylammonium salts is an important part in supramolecular chemistry.

基于冠醚类和二级铵盐的主客体化学是超分子化学领域研究的热点之一。

The chemical ring expansion is complex and expensive, and causes a significant negative environmental impact. Therefore, an enzymatic reaction is greatly desirable to replace such chemical reaction.

由於这种化学扩环不仅制程复杂，而且会对环境造成相当程度的损害，因此一种利用酵素的生物扩环法取代目前的化学法是被高度期盼的。

Chemical Milling hyperbolic face technology uses a chemical reduction process to selectively remove unwanted material, and then precise thickness control.

化学铣双曲线面对技术采用化学还原过程，有选择地去除有害物质，然后精确的厚度控制。

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。