查询词典 solvent

CH2Cl2 was a proper solvent for most of free cinchona alkaloids to achieve higher enantioselectivities, while THF was a better solvent for all the 1,4-dichlorophthalazine derivatives.

使用5mol%的催化剂获得了最佳的反应结果，3mol%的用量使ee值降低了5%，1mol%的用量则降低15%，但是当催化剂增至10mol%或20mol%，ee值也没有提高。

To improve the accuracy, as to the hardware, the quality of composite polymer films and adjustment of light path were controlled strictly, including cleanout of base, synthesis of solvent, filtering of solvent, preparation of the films and control of picturing. As to the process of picturing, adding gauge, foreground and background, many exposals in same angle were used, and the area of the films to measure was also chosen. As to software, picture analysis was mainly used to improve accuracy.

为了提高测量精度，在硬件方面严格控制复合聚合物薄膜的质量和光路的调整，包括：基片的清洗、溶液的配制、溶液的过滤、薄膜的制备、和摄像的控制等等，在采集图像的过程中，通过加标尺、测量前景和背景、同一角度下的多次曝光、薄膜测量区域的选择等等措施来消除误差；在软件方面提高测量精度方法主要采用图像处理的方法，并用自编的软件处理数据。

The invention adopts surfactant of amphipathic block copolymer as structure-directing agent to be dissolved in alcohol solvent, and niobium sources and aqueous solution of inorganic salts are added as structural promoter to be stirred for a certain period of time in the room temperature to form colloid; the colloid is then heated and volatilized under low temperature to remove the solvent and dried and calcined under high temperature to obtain the mesoporous columbium oxide.

本发明将双亲性嵌段高分子表面活性剂作为结构导向剂溶解于醇类溶剂中，加入铌源和无机盐类水溶液作为结构促进剂，在室温下搅拌一段时间后形成胶体，低温下加热挥发除去溶剂，经干燥、高温焙烧而成。

The types of solvent, content of solvent and extracting time were studied in comparison with the traditional extraction method.

研究了溶剂种类、用量和提取时间对提取率的影响，并与索氏提取法进行对比。

The experimental data demonstrated that the molar monomer (42VP)/ cross2linkerratiowasthemajorfactoraffectingtheadsorbent'scapacityfor PFOS; degree of polymerization , solvent/ water of the reaction mixture , type of organic solvent and cross2 linker affected its shape and specific surface area more significantly than its PFOS capacity.

研究结果表明：单体(42乙烯基吡啶)含量对吸附剂去除PFOS 的效果影响显著；而聚合状态、聚合液含水率、有机溶剂和交联剂的种类仅对吸附剂形态和比表面积有一定影响，但对吸附剂去除PFOS 的效果影响不大。

Neither noise level nor carbon monoxideexposure significantly correlated with hearing loss, while beingin the solvent-exposed group (highest decile of solvent indexvalues) was associated with statistically significant increasedrisk.

噪声级和一氧化碳曝光极大关联了与听力丧失，当是时在''溶剂暴露了小组(最高的十分位数溶解的索引价值)同增加的统计地重大联系在一起风险。

Classical solvent extraction is one important technology for the selective removal and enrichment of metal ions from aqueous solutions. However, it is not suitable for the separation of biological molecules such as protein and enzyme, because organic solvent can denature them.

溶剂萃取法是分析分离中最重要的方法之一，常用于金属的分离和富集，但对于生物大分子，加入有机溶剂会使其失活，因此经典溶剂萃取分离不适用，需研究新的体系。

The solubilities of ROK in several different solvents such as toluene, ether, THF and 2G were studied. Considering the influence of solvent on the microstructure of telomers, THF was determined to be the best solvent.In the system of n-BuLi/ROK/xylene/2G/olefin, the influence of ROK on diolefin anionic telomerization was investigated, and the result shows that the difference between butadiene system and isoprene system was little.

考察了不同ROK在甲苯、乙醚、四氢呋喃及二乙二醇二甲醚(2G)等不同溶剂中溶解能力，又考虑到溶剂对聚合物结构的影响，以及工业化的难易程度等方面，最终确定了ROK的最佳溶剂为THF。

The results show that the particles character as the growth of anion coordination tetrahedron during solvent thermal treatment, where blende-type ZnS particle is in the shape of double cone or tetrahedron, blend-type CdS appears as the tetrahedron, but wurtzite-type CdS is in the shape of cone. In addition, the particles with the better crystallinity are obtained with the increase of solvent thermal treatment temperature and time.

结果表明：采用溶剂热处理，粉末形状呈现负离子配位多面体生长特征，闪锌矿型ZnS粉末由球形变为双锥状或四面体状，颗粒上有明显的电子衍射花纹；闪锌矿型CdS晶体粉末主要呈四面体形状，而纤锌矿型CdS晶体粉末则以锥状为主，并且粉末的晶型随溶剂热处理温度的升高和时间的延长更趋于完整。

Introduced the reaction principle and experimental method of edulcoration arid solvent extraction, has studied the factors of solvent extraction: the phase ratio, the time, the pH, the temperature and so on.

介绍了除杂和溶剂萃取的反应原理和实验方法，研究了相比、时间、pH、温度等对溶剂萃取的影响。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。