表面活性剂对合成纳米ZnO形貌及光致发光性能的影响研究

以醋酸锌和氢氧化钠为原料,采用水热合成法制备纳米ZnO,并研究表面活性剂的种类对纳米ZnO形貌以及光致发光性能的影响。通过红外光谱（IR）、X-射线衍射（XRD）、扫描电镜（SEM）和光致发光谱（PL）测试对样品进行表征,结果表明,相比阴离子表面活性剂,添加阳离子表面活性剂制备出的纳米ZnO的形貌以及光致发光性能更佳。     

Au与ZnO极性表面相互作用的第一原理计算

采用第一原理研究了Au在ZnO两个极性表面（0001）-Zn和（0001）-O的吸附,分析了单层Au吸附在ZnO极性表面上的态密度和吸附构型.计算结果表明：ZnO极性表面上单层Au吸附层能提高Zn原子在（0001）-Zn和（0001）-O面上的吸附能分别0.41 eV/原子和0.42 eV/原子;同时Au吸附层又比Zn吸附层更加活跃,总能计算可以看出Au处于顶端的构型比Au扩散构型更加稳定,使得Au恒处于顶端,很好的解释了Au在ZnO纳米结构生长过程中充当表面活性剂的角色.理论计算与实验中发现Au颗粒总是在生长出的纳米结构的末端这一现象吻合很好.     

介绍一个综合化学实验——ZnO微纳米花的制备及其气敏性能

设计了一个简单的ZnO微纳米花液相合成、表征及其气敏性能测试综合化学实验。在低温下．用液相合成法大规模制备出纳米片组装成的ZnO微纳米花。用X射线粉末衍射（XRD）和扫描电子显微镜（SEM）表征产物的结构和形貌。制作出ZnO微纳米花气体传感器,测试ZnO微纳米花传感器对易挥发有机气体的敏感响应。该实验使学生了解氧化锌微纳米花的制备原理和方法,熟悉纳米材料的主要表征手段。掌握气体传感器的制作及其气敏测试原理和方法。系统全面地了解纳米材料的制备、表征和应用,极大地丰富了学生的知识面,有利于激发了学生的探索知识的兴趣,培养学生的科研能力。     

纳米ZnO涂层的光吸收性能研究

用沉淀法制备了纳米ZnO,通过控制反应条件得到了几种不同粒径分布范围的纳米级ZnO粉体,用AFM和XRD方法对纳米ZnO样品进行了表征,采用共混法将不同粒径的纳米ZnO粉体制成涂层,利用光透射实验装置测试了涂层的光吸收性能,且与普通ZnO进行了对比．结果表明：纳米ZnO比普通ZnO有较强的光吸收能力,且随着纳米ZnO粒径的减小,光吸收能力相应地变强．     

氨水体系中制备ZnO纳米棒及其生长机理

对氨水溶液体系中种子层法制备ZnO纳米棒的生长机理进行研究。采用溶胶-凝胶法制备出具有002择优取向的ZnO种子层薄膜,利用XRD研究旋涂速度和热处理温度对薄膜取向性的影响;采用密闭高压的氨水溶液体系制备出具有高比表面的ZnO纳米棒,利用SEM对Zn O的微观形貌进行表征,并说明了氨水体系下ZnO纳米棒薄膜的生长机理。测试果表明,4000r/min及300℃的热处理温度制备的ZnO种子层薄膜具有显著的002择优取向,有利于后续ZnO纳米棒沿002方向择优生长。氨水体系下,所获得的ZnO纳米棒长径比大于50,且顶部呈六角锥形,棒与棒之间的空隙较大,有利于敏感气体和量子点的吸附。     

不同形貌氧化锌纳米结构的水热合成、表征和场发射特性

以Zn（NO3）2.6H2O和NaOH为原料,采用改进的水热法通过控制反应溶液的浓度、反应温度和反应时间等沉积参数,合成了包括氧化锌纳米棒阵列、蜂窝状氧化锌纳米棒、花状氧化锌纳米棒等纳米结构.用XRD、SEM和HR-TEM对样品进行了表征,结果表明所制样品为六方纤维锌矿结构的ZnO晶体;SEM测试结果显示ZnO晶体的形貌呈花状和蜂窝棒状等形貌,HR-TEM结果表明单晶纳米棒沿[0001]方向生长.研究了玻璃衬底上装配的花状氧化锌纳米棒的场发射特性,测试结果表明花状氧化锌纳米棒具有优良的场发射;开启场强为4.3V/μm,当场强为8V/μm时,发射电流密度达到2.2mA/cm2.     

含Co配合物的ZnO纳米棒复合材料光电化学性质

在氧化铟锡(Indium Tin Oxide,ITO)玻璃上制备ZnO纳米棒,并采用一种简单的自组装方法在含有ZnO纳米棒的ITO玻璃上制备Co(2. 6-NDC)(4,4'-Bipy)0. 5配合物。实验表明,含Co配合物并没有和ZnO纳米棒发生反应,而是比较均匀地沉积在ZnO纳米棒上。在光电化学实验中,做了仅有ZnO和含Co配合物的ZnO纳米棒的线性伏安法测试对比实验,证明含Co配合物起到了良好的催化能力。说明这种简单的自组装方法制备的金属氧化物半导体和MOFs组成的复合材料在光电化学中具有潜在的应用价值。     

正交实验法优化Ag／ZnO纳米复合抗菌剂的合成工艺

以纳米氧化锌为载体,采用正交试验法研究了Ag／ZnO纳米复合抗菌剂的最优合成工艺。实验结果表明,Ag／ZnO质量比、反应时间、反应温度、溶液的pH值都对纳米氧化锌对Ag^＋的吸附率有影响;采用纳米Ag／ZnO矿质量比为20：1,pH值为8,在60℃的水浴中机械搅拌60min为最佳制备工艺。     

氧化锌纳米棒的水热制备及电化学性能研究

采用一步水热法制备了纳米棒状氧化锌材料.X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜法(TEM)测试表明,ZnO纳米棒为纤锌矿结构,直径为200～500nm,长度为3～5μm.通过充放电循环和循环伏安等电化学方法研究了ZnO纳米棒的电化学性能,ZnO纳米棒展现出较高的放电容量和较低的容量衰减率.经过100个循环之后,ZnO的放电容量仍然维持在380mAhg-1.     

片状ZnO纳米结构的制备及光学性质分析

在无催化剂的条件下,采用溶胶凝胶与化学气相沉积相结合的方法,制备出了高产率的片状ZnO纳米结构。并利用扫描电子显微镜、X射线衍射仪、拉曼光谱仪和荧光测试仪对其结构和性质进行了分析。结果表明,所合成的产物为结晶良好的片状纤锌矿ZnO纳米结构,室温光致发光谱显示,该ZnO纳米结构表现为弱的紫外发射峰和强而宽的绿光发射峰。     

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.