查询词典 functional group

This study is to give a solution for the estimation of flash point for mixtures, the necessity for classification of flammable liquids. The traditional models for predicting flash point of mixtures usually by the activity coefficient approach. However, the parameters of activity coefficient were regressed from phase equilibrium data in the literatures. If there is no such parameter in literatures for the desired mixture, the model cannot predict the flash point oft hat mixture. Thus, this research aims at the improvement of deficiency of the flash point prediction models in the literatures by useing UNIFAC (Universal Quasi-chemical Functional Group Activity Coefficient) equation, Dortmund-UNIFAC equation and Lyngby-UNIFAC equation. In this study, we were aim at the prediction model for miscible mixtures.From the result, it is suggested to use different type of UNIFAC equation to estimast activivity coefficient in the predition of flash point for different mixture type.

易燃液体分类的主要依据参数为闪火点值，因此本研究目的为解决易燃液体中混合物分类时所面临到的闪火点值缺乏的问题，而在过去文献中所提出的闪火点预测模式会使用到活性系数，但这些模式使用到的活性系数均需要相平衡的数据以回归其所需参数，若所欲估算闪火点的混合溶液文献上未有相关参数，则无法有效利用闪火点预测模式估算其闪火点，因此针对文献中现有闪火点预测模式的缺点，利用描述液体混合物活性系数UNIFAC (Universal Quasi-chemical Functional Group Activity Coefficient)方程式、Dortmund-UNIFAC方程式和 Lyngby-UNIFAC方程式，建立发展一闪火点预测模式，而本研究以互溶溶液为对象。

The results showed that the preoxidation of PPESK was a free radicals reaction,which was initiated by the decomposition of proton in aromatic ring and sulfone functional group and the removal of H_2O and SO_2.When the preoxidation temperature was above 460℃,the radical reaction was initiated by the decomposition of ketone functional group and the removal of CO_2.At last,the three-demensional cross-linking structure containing polyaromatic ether and biphenyl was formed.

研究表明，PPESK的预氧化过程是一个自由基反应过程，始终伴随着芳香环质子和砜基官能团的脱除引发的自由基交联反应，脱出H_2O与SO_2；当预氧化温度超过460℃后，随着反应的进行，由羰基官能团分解引发的自由基交联反应开始发生，脱出CO_2，并最终形成了含有大量聚芳醚和联苯结构的稳定的三维空间网状结构，进而完成PPESK由热塑性材料向热固性材料的转化。

In this paper, from the viewpoint of latent functional group, application and development of heterocyclic compounds such as furan nucleus and thiofuran nucleus used in organic synthesis as pre-functional group are introduced.

本文从潜官能团角度概括介绍了呋喃环和噻吩环作为前官能团在有机合成中的应用及进展，展望了杂环作为前官能团在天然产物合成中的重要意义。

Phenol: Any of a class of organic compounds with a hydroxyl group (-OH; see functional group) attached to a carbon atom in a ring of an aromatic compound.

酚：以羟基(-OH；参阅functional group)与芳香族化合物环上的碳原子相连为特征的一类有机化合物。

Objective to evaluate the functional recovery of acute spinal cord injuried rats treated with exogenous wnt-3a signal protein administration and to explore its mechanism.methods moderate spinal cord contusion injury was made in 40 adult sprague dawley rats at t10.twenty rats served as contusion controls(group 1).twenty rats were treated with wnt-3a for three days after injury (group 2).the functional recovery of the rats was observed through basso,beattie,bresnahan open field locomotor score.rats were killed at 14 or 28 days after injury,then spinal cords were removed for histopathological examinations,and the expression of the bromodeoxyuridine plus neural cell markers was stained with immunohistochemical method.results rats of two groups receiving a contusive injury recovered substantial function within 1 week.by 28 days,rats in groups 2 scored 7.0 points better on the bbb scores than rats in group 1 group 2=16.94,after 28 days vs.

目的 研究外源性wnt-3a信号蛋白对脊髓损伤的修复作用，并探讨其作用机制。方法取40只成年雌性sd大鼠在t10节段制备适度脊髓挫伤模型。随机从中取20只为损伤对照组(group 1)，另外20只为损伤治疗组(group 2)。脊髓损伤3天后用wnt-3a蛋白治疗。这些大鼠的功能恢复通过basso、beattie、bresnahan开放视野运动评分来观察。这些大鼠分批在损伤后14天或28天被处死，取出损伤节段脊髓用来组织病理学检查，同时用5-溴脱氧尿嘧啶核苷和神经细胞标记物进行免疫组化染色。结果两组大鼠在伤后一周运动功能有明显的恢复。不过，到损伤后28天，我们观察发现，损伤治疗组中的大鼠bbb评分比损伤对照组中的评分高出7.0分左右(group 2∶16.94±1.18，group 1∶9.89±1.29；p.05)，光镜和电镜检查发现wnt-3a蛋白对髓鞘形成和轴突再生有一定的修复效果。

With the deflected succession of aquatic ecotype plant functional group,the dominance of mesophytes and xerophytes increased,while the dominance of aquatic and hygric plants decreased. However,there are only planting crops in the reclaimed wetland. In the composition of plant biotype functional group,the hydrophytes reduced quickly with the deflected succession and the dominance of perennial herbs is mostly marked,and there are only annual herbs in reclaimed wetland. Compared with primary swamp,the species diversity index of meadow is the highest,the swampy meadow follows,and the reclaimed wetland is the lowest.

植物的水分生态型功能群组成随湿地的逆行演替，水生、湿生类植物功能群的优势度不断减少，中生、旱生类植物功能群的优势度逐步增加，而在垦后湿地只有农作物；植物生活型功能群组成随湿地的逆行演替，水生草本迅速减少，陆生多年生草本增加占据优势，而在垦后湿地均为一年生草本；湿地植物物种丰富度、多样性指数由原生沼泽、沼泽化草甸到草甸依次增加，草甸为最大值，而垦后湿地则最低。

Through copolymerizing AA and AN in different mole ratio, and compare the PV performance with membrane of PVA acetal membrane, we can concluded that, the separation flux of composite membrane is less than PVA acetal membrane, however, when the mole ratio of AA and AN is 1:1, the separation factor is higher than PVA acetal membrane, from the view of PSI, the composite membrane is better, thats the reason of the hydrophilic functional group and hydrophobic functional group ratio proper, it achieved good balance.

经过研究得到相对最佳的制膜条件：PVA浓度10％，甲醛浓度36％，采用加热到75℃的方法缩醛和制膜，热处理时间为15min；AA与AN的投料摩尔比为1比1左右，复合膜厚为30gm。通过渗透汽化指数的综合衡量，得到对于共聚复合膜最佳的使用温度为50℃左右。

Our results showed 1 The changes in trends of leaf traits response to the rainfall gradient differed either with species or with a specific trait; 2）The same trends were found at the functional group level, However, leaf traits for grasses tends to be less sensitive, then for forbs, and the legumes is the most sensitive functional group along the rainfall gradient, indicated that the Grass function group is quite strong to the soil moisture content tolerance, and which certainly explained to the local vegetation distribution and the substitution between species.

主要结论如下：1 叶片性状在降雨量梯度上的变化趋势在物种水平上表现出多样化的特点，性状的变化趋势是否有显著的格局取决于物种或特定性状。2 叶片性状对水分梯度的响应在功能群水平上表现出各自的特点，Grass功能群对水分梯度的响应敏感性较低，Forb居中，Legume表现出较强的敏感性，表明Grass功能群对水分的耐受性比较强，这在一定程度上解释了当地克氏针茅草原上目前以禾草类为主的现状，对物种之间的替代有一定的指示性。

Based on the judgement on the existing of whether leading functional group or unleading functional group,if unleading exists,what about its bond type,with these pre-classification information,a new classification methods and uint structure model which can reflect the name,composition,stucture and function was put forward in this paper.

前言 高性能混凝土外加剂分子只存在磺酸、羧酸两种主导官能团，以磺酸、羧酸、&磺酸-羧酸&三种方式存在，因而把高性能外加剂分成磺酸、羧酸、&磺酸-羧酸&三大系列 [1、2 ]。磺酸系列外加剂的一个重要性能是高减水率，故有时将它称之为高效减水剂。

This means that the species composition of functional group has significant effect on the biomass of functional group.

与正常对照相比，干旱胁迫条件下优势物种和功能群组成对样地生物量的影响作用明显改变。

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。