LC/MS法测定纺织品中残留烷基酚和烷基酚聚氧乙烯醚

以甲醇为提取溶剂,采用微波辅助萃取法提取纺织品中残留的辛基酚、壬基酚、辛基酚聚氧乙烯醚、壬基酚聚氧乙烯醚,用高效液相色谱-质谱法进行测定,并对前处理条件进行了优化。该方法的检测限(S/N=5)为0.010-0.025μg/mL,回收率为93.19%-103.97%,精密度实验的相对标准偏差为1.03%-4.96%。     

氧化还原引发下的苯丙乳液聚合

以苯乙烯、丙烯酸丁酯为混合单体,十二烷基硫酸钠和壬基酚聚氧乙烯醚为复合乳化剂,过硫酸钾和亚硫酸氢钠为氧化还原引发体系,进行乳液聚合制备苯乙烯-丙烯酸丁酯水性共聚乳液.用粒度测定、红外光谱和热分析等仪器对聚合乳液进行了表征.结果表明引入氧化还原体系合成苯丙乳液能在较低温度下引发进行,乳液聚合产物的性能较好.     

DDP表面修饰ZnS纳米微粒作为润滑油添加剂的SEM研究

利用四球摩擦磨损实验机考察了粒径约为3nm的二烷基二硫代磷酸(DDP)修饰ZnS纳米微粒作为润滑油添加剂的抗磨行为,并用扫描电子显微镜(SEM)和能量散射谱(EDS)等现代分析手段对其摩擦表面进行了分析.结果表明,DDP修饰ZnS纳米微粒作为润滑油添加剂能够明显提高基础油的抗磨能力.SEM及EDS的分析结果表明摩擦过程中在摩擦表面形成了一层富含Zn、S、P元素的反应膜,正是这层膜的存在使得DDP修饰ZnS纳米微粒作为润滑油添加剂具有良好的抗磨性能.     

苯乙烯与甲基丙烯酸十二酯无皂乳液聚合及性能研究

以氯仿-甲苯为溶剂,用溶液聚合法合成苯乙烯-马来酸酐(SMA)共聚物,经过氨水溶解得到SMA水溶性分散剂。该分散剂与苯乙烯(St)、甲基丙烯酸十二酯(LMA)采用无皂乳液聚合法制备SMA的无皂乳液。探究了单体配比、LMA、SMA等因素对无皂乳液性能的影响,得出反应合成的最佳条件是:m(St)∶m(LMA)=2.67∶1.00,LMA的用量(相对于混合溶液)为5%,SMA的用量(相对于混合溶液)为8%。用红外、热分析等分析手段对共聚物进行结构表征与性能分析。实验结果表明,SMA无皂乳液涂膜有良好的耐水性能和耐有机溶剂性能,且具有较高的热稳定性能,在328.58℃开始失重,玻璃化温度在165.7℃。     

气相色谱法对壬基酚聚氧乙烯醚裂解条件的选择

壬基酚聚氧乙烯醚是一种商用的非离子表面活性剂,在油砂分离过程中起到了很大的作用。因其对环境的影响,所以对其含量的测定是非常有必要的。利用氢碘酸对壬基酚聚氧乙烯醚进行裂解,通过气相色谱对裂解物壬基酚的峰面积或者峰高找到最佳的裂解条件,并且重现性很好,精确度达到3%,并通过气-质联用对裂解物进行定性,裂解条件的选择对定量提供了方法。     

水溶性聚乙烯醇缩乙二醛胶粘剂的制备

探讨了水溶性聚乙烯醇缩乙二醛合成的工艺条件,比较了聚乙烯醇缩乙二醛与聚乙烯醇缩甲醛的性能,以m(聚乙烯醇):m(水):m(乙二醛)=15:150:6,在温度80-85℃,PH值为2.0的条件下,聚乙烯醇与乙二醛在水溶液中发生缩合反应生成的聚乙烯醇缩乙二醛,完全可以替代水溶性聚乙烯醇缩甲醛粘接剂.     

关于水溶性卟啉合成的一点研究

以mleso-四(4-吡啶基)卟啉1为原料，合成了水溶性的nleso-四(4-N-甲基吡啶基)卟啉(TMPyP)2，目标化合物均由红外光谱，紫外-可见光谱表征并确证．     

皮革中烷基酚聚氧乙烯醚含量的高效液相色谱质谱法测定

该文建立一种测定皮革制品中烷基酚聚氧乙烯醚的高效液相色谱质谱(HPLC-MS)分析方法 .采用甲醇溶剂对样品进行超声提取,经滤膜过滤后直接进样,正离子选择离子监测模式进行定性和定量分析.结果表明：辛基酚聚氧乙烯醚和壬基酚聚氧乙烯醚在0.05～2 mg/L浓度范围内具有良好的线性关系,相关系数(r²)均在0.999以上,方法检出限分别为0.42 mg/kg和0.54 mg/kg.在3个加标水平下的平均回收率分别为79.5%～90.7%和83.0%～119.5%,相对标准偏差(RSD,n=6)分别为2.4%～3.2%和0.3%～4.3%.该检测方法具有简捷、准确、稳定可靠等特点,可用于皮革制品中烷基酚聚氧乙烯醚的分析检测.     

4-乙酰氧基苯甲酸的绿色合成

研究了以乙酸酐和4-羟基苯甲酸(PHB)为原料,以氨基磺酸为催化剂合成4-乙酰氧基苯甲酸(PABA)的绿色合成方法,考察了影响合成反应的诸多因素.最佳合成条件是4-羟基苯甲酸和乙酸酐的摩尔比为1.0∶2.0,催化剂氨基磺酸用量为4-羟基苯甲酸质量的5％,反应温度为80℃,反应时间为60min;4-乙酰氧基苯甲酸的收率为92.2％.该方法操作简单,原料价廉易得,后处理方便,且产率高,反应条件温和,无环境污染,对工业生产及实验教学有积极的指导意义.     

(3S,4S)-N-苄基-3,4-二羟基氢化吡咯的合成工艺条件研究

以(R,R)-(+)-酒石酸为原料,合成了(3S,4S)-N-苄基-3,4-二羟基氢化吡咯,利用1HNMR、12CNMR对合成的产物进行性能表征。采用单因素分析方法,系统研究了物料的摩尔比,还原剂,反应时间等因素对产品收率的影响,实验结果表明:以NaBH4/I2做还原剂,n(底物)∶n(NaBH4)∶n(I2)=1∶5∶1.68,反应时间为6 h是获得较高产率的最佳工艺条件。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.