溶剂

In this thesis, this system is used for epoxidation of propylene and styrenewith good results. The solvent effect is investigated for epoxidation of styrene. In the mixedsolvent of dimethyl phthalate / TBP or phenyl ether / TBP, the selectivity for styreneoxide is good but the conversion of styrene is low due to the coordination to thecatalyst of the solvent. When part of dimethyl phthalate or phenyl ether is replacedby toluene, the conversion increases and the selectivity keeps constant.

邻苯二甲酸二甲酯或二苯醚等与磷酸三丁酯的混合溶剂中环氧化的选择性较高，但由于溶剂对催化剂的配位作用抑制了催化剂的活性，苯乙烯转化率很低；当部分的邻苯二甲酸二甲酯或二苯醚被甲苯取代后，苯乙烯的转化率提高，生成环氧苯乙烷的选择性不变。

The experimental results show that in the presence of acetic anhydride, the L-tyrosine can be completely racemized and converted into DL-tyrosine both in NaOH aqueous solution and in acetic acid solvent, and moreover, in the presence of acetic anhydride

今讨论了在碱性水溶液中，L-酪氨酸、乙酸酐和NaOH三者摩尔比例对消旋过程的影响和在纯乙酸溶剂中，乙酸用量和L-酪氨酸与乙酸酐的摩尔比例与消旋温度对消旋过程的影响。结果表明在乙酸酐的作用下，L-酪氨酸在纯乙酸溶剂中的消旋具有消旋速度快，DL-酪氨酸收率高的优点。

The results show that: the tensile strength, flexural strength and flexural modulus increase by about 10.4%, 62.1% and 122.3% respectively when the mass fraction of the aluminum powder increases from 0 to 50%, while elongation at break and impact strength decrease by about 65.0 and 74.4% respectively; the tensile strength, elongation at break and impact strength all increase with decreasing the particle sizes of the aluminum powders.b Nylon-12 coated metal powders for the indirect SLS process were prepared by the dissolution precipitation process. The coated powders have only 1.0 wt% nylon-12, and their SLS green parts have sufficient strength for features as small as 1.0 mm to be built and post-processed and high dimensional accuracy. The green parts were subjected to the post processing processes including binder decomposition and infiltration of epoxy resin, and then the metal/polymer composite parts with relatively high strength and accuracy were formed.At present, micron-scale inorganic fillers have been widely used to reinforce nylon SLS parts.

将该法制备的尼龙12覆膜金属粉末用于以下两个方面：a使用铝粉增强尼龙12的SLS成形件，通过溶剂沉淀法制备尼龙12覆膜铝复合粉末，研究了铝粉含量及粒径对SLS成形件性能的影响，结果表明：铝粉分散均匀，并与基体有良好的界面粘接；当铝粉含量从0增加到50wt％时，成形件的拉伸强度、弯曲强度、弯曲模量分别提高10.4％、62.1％和122.3％，冲击强度和断裂伸长率下降65.0％和74.4％，耐热性及尺寸精度也得到提高；断裂伸长率、冲击强度及拉伸强度均随着铝粉粒径的减小而增大。b使用溶剂沉淀法制备了间接法SLS用尼龙12覆膜金属粉末，该覆膜粉末中聚合物粘接剂的含量仅为1.0 wt％，其SLS初始形坯具有较高的精度以及足够满足后处理要求的强度，最小精细结构的尺寸达1.0 mm。

Topics discussed include ultrafast spectroscopic techniques; aspects of electron transfer reactions ranging from solvent effects; intermolecular and intramolecular systems, to dynamics at semiconductor surfaces; the dynamics of chemical systems using Raman spectroscopy; pericyclic photochemical rearrangements and photodissociation reactions; solvent--solute interaction dynamics; and chemical dynamics in clusters.

讨论的议题包括超快光谱技术，电子转移反应的溶剂效应等方面；分子间和分子系统，动力在半导体表面，使用的化学拉曼光谱系统动力学；周环重排和光化学解离反应；溶剂-溶质相互作用的动态以及在化学动力学组。

The effects of some important factors on structure, pore size, porosity, flux, weight of vapor transfer, etc. have been investigated by changing temperature of PVDF resolution, types of solvent, molecular weight of PVDF, weight of additive, time of solvent pre-evaporation and so on. The optimal process of making membrane and recipe of solution were made out.

然后通过改变PVDF溶解温度，铸膜液的溶剂，PVDF的分子量，PVDF用量，添加剂氯化锂用量，涂膜时预挥发时间，凝固浴温度以及凝固浴中无机盐氯化钠、溶剂丙酮等影响因素，考察这些因素对膜形态结构及孔径，孔隙率，水通量，透湿量等性能的影响规律，初步确定了铸膜液配方及涂膜工艺条件。

This product mainly by the surfactant, environment-friendly organic solvents, penetrants, such as by the composition of solvent.

本品主要是由表面活性剂、环保型有机溶剂、渗透剂、增溶剂等组成。

The company specializes in selling outdoor pictures machine, various types of imported articles of piezoelectric household (including ROLAND | MUTOH | MIMAKI) converted outdoor machines, the company modified the introduction of technology imports, Europe and the United States imports of ultra-green ECO weak solvent ink, no Smell, the Mexican colorful, soft-degree, offset the weak domestic market low solvent precision machinery, converted imperfect, poor technology, re-ink smell, and so on defects at the same time, strengthen the control of color, wholly owned indoor pictorial effect , Also reduce the cost, the use of our technology can be modified in the absence of coating on the print media, anti-ultraviolet, scratch-resistant, waterproof, outdoor weathering more than two years, modified aircraft to meet the environmental requirements of customers for the super Weathering the outdoor performance.

本公司专业销售户外写真机，各类进口压电户内写真机(包括ROLAND|MUTOH|MIMAKI)改装户外机，本公司引进进口改装技术，欧美进口超环保ECO弱溶剂墨水，无任何异味，不断墨色彩鲜艳，柔和度强，弥补了国内市场弱溶剂机器精度低、改装不完善、工艺差、墨水异味重等等缺陷的同时，加强了色彩的控制，完全拥有户内写真的效果，成本也有所降低，使用我们的改装技术可在无涂层介质上打印，抗紫外线，耐刮擦，防水，户外两年以上耐候性，改装机在满足环保要求的同时为客户提供超强的户外耐候性能。

Preferred organic solvents are polar in nature as these tend to wet metals and alloys better and since the polar solvent itself may readily be washed from the metal with water.

首选极性有机溶剂的性质，因为这些往往湿金属和合金的更好，因为极性溶剂本身可能很容易地从金属与水冲洗。

In the state of vacuum,the boilling point of raw material will be dr-opped.therefore it is suitable for drying raw materials that are unstable or thermalsensitive.the vacuum drier also has good airtighenss.so it is also for drying raw materials that contain strong irriative and toxic gases and toxicgases and the solvent needs to recover.

真空状态下物料溶剂的沸点降低，所以适用于干燥不稳定或热敏性物料；真空干燥机有良好的密封性，所以又适用干干燥需回收溶剂和含强烈刺激，有毒气体的物料。

Through XRD analysis, as the temperature of cosolvent and mass transport goes up, the wave peak intensify of tin dioxide becomes more obvious. By means of SEM, tin dioxide particulates are found evenly distributed on the matrix and the quantity of particulates become higher with the increasing cosolvent concentration. The size of particulates is about 30-50nm.

经XRD分析，复合材料中二氧化锡之波峰强度随潜溶剂浓度与质传温度之增加越趋明显；SEM观察则发现，二氧化锡颗粒析出物系均匀分布於基材内，且析出物的含量随潜溶剂浓度增加而增加，析出物的尺寸约30-50nm。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。