溶液表面吸附实验拓展

对经典的物理化学实验"溶液表面吸附的测定"进行了拓展,将体系由单一的正丁醇溶液扩展成正丁醇、异丁醇和叔丁醇一系列同分异构体。分别测定了3种醇溶液在不同浓度下的表面张力,拟合实验数据进而计算得到了单分子的占有面积,并与chem3D软件的理论模拟进行了比较。结果表明,实验求得吸附量和单分子占有面积的同时,可以有效地区分分子纳米尺度的结构差异。实验有助于增强学生对微观的具象认识,并对表面吸附实验有更加深刻全面的理解。     

氨基磺酸系高效减水剂AH的分散机理研究

实验测试了氨基磺酸系高效减水剂AH溶液的表面张力、AH在水泥颗粒表面的吸附量及ξ电位,结果表明：AH能够减小溶液表面张力,使分散体系的自由能降低;它在水泥颗粒表面呈环圈及尾状吸附,产生较大的立体空间位阻;掺AH的水泥粒子表面ξ电位绝对值较大,水泥颗粒间存在着较强静电斥力。这些均使得AH具有良好分散作用。此外,AH分子结构中存在的极性基团与水分子间的氢键缔合,在水泥粒子表面形成的溶剂化水膜的润滑,也对AH分散起到一定的加强作用。     

应用Excel规划求解处理表面张力测定实验数据

在表面张力测定实验数据处理中,利用Excel2007规划求解功能对表面张力和浓度关系中的待定参数进行非线性最小二乘拟合求解,得到拟合参数a,b。结合希斯科夫斯基经验公式和吉布斯吸附等温式可方便求出表面吸附量的数值,并绘制表面吸附量和浓度的关系曲线。整个处理过程无需编程,可快速、简便、准确地完成数据处理任务。     

计算机在溶液表面张力测定中的应用

本文利用计算机绘图计算功能,将其应用于物理化学实验--溶液表面张力测定实验,通过计算机对其进行数据处理后表明:该方法直观、简单、快速.尤其适用于表面活性剂物质的表面张力[1,2]测定.     

利用ExceI处理物理化学实验的非线性关系数据的研究

本文应用Excel2003中的规划求解功能,对最大气泡法测定溶液的表面张力实验中表面张力和浓度的非线性关系数据进行了处理,并方便的求出了正丁醇饱和吸附量及其分子的横截面积。用实例说明了Excel软件处理非线性关系数据过程简单、快捷,并提高了效率和准确性。     

利用Excel处理物理化学实验的非线性关系数据的研究

本文应用Excel 2003中的规划求解功能,对最大气泡法测定溶液的表面张力实验中表面张力和浓度的非线性关系数据进行了处理,并方便的求出了正丁醇饱和吸附量及其分子的横截面积。用实例说明了Excel软件处理非线性关系数据过程简单、快捷,并提高了效率和准确性。     

短链醇溶液表面张力及表面吸附测定的实验研究

分别测定得到6种短链醇溶液在不同浓度下的表面张力,考察了分子结构对表面张力和吸附性能的影响,提出了适用于综合实验的醇类稀溶液浓度范围,并利用Origin软件分别基于传统数据处理方式和曲线拟合方式计算得到吸附分子的横截面积。通过此实验,力求针对最大压差测定方法、处理实验数据和理论知识点3个目标层次,使学生尽可能全面地掌握表面化学相关实验原理和技术、数据处理方法,加深影响表面张力和吸附测定的因素和相应的概念、理论的理解,努力培养和提高学生实际应用能力。     

公式拟合法计算乙醇水溶液的表面吸附量

建立了乙醇水溶液的表面张力σ与浓度c的关系，由此式求出（Dσ／Dc）r，再由吉布斯吸附公式计算各浓度的表面吸附量г。所求得的г随c的变化规律与文献吻合。     

正丁酸表面吸附量的测定

对气泡最大压力法测定正丁酸表面张力进行了研究,并根据Langmuir吸附等温式得到正丁酸表面吸附量和单个正丁酸分子表面积。     

埃洛石纳米管表面修饰及其对次甲基蓝的吸附研究

采用硅烷偶联剂对埃洛石纳米管(HNTs)进行表面修饰,通过透射电子显微镜(TEM)、红外光谱仪(FTIR)、分光光度计等对HNTs的结构和吸附性能进行了表征。结果表明,硅烷偶联剂通过化学键实现了对HNTs的表面修饰,提高了HNTs在溶液中的分散稳定性;适当提高溶液温度、延长吸附时间及增加溶液pH值有助于提高HNTs对次甲基蓝的吸附量。当溶液温度为303K,吸附时间为90min,溶液pH值为7时,表面修饰HNTs的吸附量可达8.91mg/g,相对于表面未修饰HNTs(同等条件下的吸附量为7.83mg/g)明显提高。吸附后的表面修饰HNTs经过再生处理后,吸附量可达到7.66mg/g。     

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.