首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 515 毫秒
1.
系统梳理了电离、离子反应专题的已有研究,分析了电离、离子反应内容对学生认识发展的作用,进而确立了化学1模块电离、离子反应专题的教学论问题并进行了阐述分析。在上述研究的基础上,设计了化学1模块电离、离子反应专题的单元整体教学,并进行了教学实践,取得了较好的教学效果。  相似文献   

2.
低维ZnO纳米材料*   总被引:1,自引:0,他引:1  
杨森  倪永红 《化学进展》2007,19(10):1510-1516
本文主要综述了近年来ZnO纳米材料制备领域的一些新方法,简单比较了各种方法之间的优缺点;讨论了制备不同形貌的ZnO纳米材料的影响因素,其中重点讨论了表面活性剂的作用;介绍了ZnO纳米材料的性质及其可能的应用领域;并对ZnO纳米材料的发展前景进行了展望。  相似文献   

3.
基于工程教育专业认证标准的要求,结合专业课程的特点,对我校制药工程专业的分析化学实验教学大纲进行了标准化改造。标准化的教学大纲更加突出了专业适用性,关联了教学要求与教学内容和考核评定,增加了考核量化指标与课程持续改进的方式,进一步规范了分析化学实验课程的教学。标准教学大纲的构建为实验教学活动提供了更加明确的指导,有利于缩小不同教师教学的差异性,保证了实验教学的质量,为建立可持续完善的工程类实验教学标准体系提供了具体参考。  相似文献   

4.
储氢合金电极的表面修饰研究   总被引:1,自引:0,他引:1  
杨凯  吴锋  李丽  王敬 《物理化学学报》2003,19(12):1167-1170
利用等离子体技术对AA型MH/Ni电池的储氢合金电极进行了镀覆导电膜层的表面修饰,用XRD及SEM对电极结构进行了表征.极片经过表面修饰的电池,其内阻降低了24%,放电容量有了明显提高,5C (7.5 A) 放电容量提高了200 mA•h,放电平台电压提高了约0.14 V,导电膜层还起到了电极保护层的作用,抑制了合金的粉化,提高了电池的循环稳定性.同时,电池内压显著降低,电池性能有了较大改善.  相似文献   

5.
针对无机化学传统教学模式的不足,构建了无机化学微信平台。介绍了构建平台必需的微信公众号和微信群的建立过程和方法。分析了无机化学微信平台在教学中的实践效果,弥补了传统教学中的不足。讨论了无机化学微信平台的积极作用,提高了教师教学水平和学生的学习能力,达到了师生双赢的目的。  相似文献   

6.
左旋薄荷醇的合成现状及进展   总被引:1,自引:0,他引:1  
陈旭敏  黄山  陆涛  赵小龙  姜标 《有机化学》2009,29(6):884-890
阐述了左旋薄荷醇的理化性质及其应用现状和全球生产状况. 介绍了薄荷醇的合成思路、已经工业化的合成路线和一些有较高工业应用价值的路线, 并介绍了关于这些路线的最新研究进展. 最后对所介绍的路线进行了总结, 展望了其发展前景.  相似文献   

7.
杜鹃花科植物有毒成分的电子结构及构效关系   总被引:10,自引:0,他引:10  
本文应用INDO方法, 对由杜鹃花科植物中提取分离的九个化合物进行了量子化学计算, 得到了分子轨道波函数等多种电子结构信息, 并计算了这些化合物活性部位的分子静电势, 得到了静电势图。用分子图形技术与药理性质相同的其它生物碱类毒素进行了空间结构比较。研究了它们的电子结构特征和活性部位, 讨论了作用机理及电子结构与毒性之间的关系。  相似文献   

8.
基础化学实验室的建设与管理   总被引:2,自引:0,他引:2  
褚秋霞 《化学教育》2009,30(7):66-67,72
化学实验室是全面完成化学教学任务的重要基地。 我院2002年建立了设备比较先进的化学实验室,给学生创造了良好的实验条件,并进行了科学化的管理,规定了各种规章制度和有关职责,较好地完成了化学教学任务。在实践中。采取:固定优秀代课教师兼管,勤工助学学生帮忙的管理办法,既减轻教师的劳动强度,又培养了学生的技能,且协调了各种关系,有利于化学教学质量的提高。  相似文献   

9.
手性羟酸和氨基酸类化合物的构效关系研究   总被引:1,自引:0,他引:1  
刘东  章文军  许禄 《化学学报》2009,67(2):145-150
构造了用于手性参数衍生的距离矩阵和扩展的距离矩阵, 并且观察了与羟酸类和氨基酸类化合物手性薄层色谱保留指数的相关性, 得到了具有启示性的结果. 引进了扩展的eAm指数和连乘指数, 以及综合运用了三种算法. 所得参数进行了多元回归分析, 得到了单一变量和变量组合的分析结果. 与多元回归分析相比较, 运用人工神经网络法, 使结果得到了较大的改善. 所引进的方法对于化合物构效关系研究具有普遍可用性.  相似文献   

10.
农科有机化学课程建设的探索与实践   总被引:1,自引:0,他引:1  
对农科有机化学课程存在的一些普遍问题进行了分析;结合当前农林院校的特点,建立了符合农业院校特点的教学新体系;编制了一系列教材;建设了精品课程网站;建立了教学质量评价体系;建设了一支结构合理、教学水平高、团队精神好的教学队伍。  相似文献   

11.
The effect of film thickness on the structural conformation of the surfaces of the amorphous state, edge‐on lamellae and flat‐on lamellae of a semiflexible polymer, poly(bisphenol‐A‐etheroctane), was investigated by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) with the aid of principal component analysis (PCA). PCA results empirically indicate that a structurally regular polymer surface was obtained with the formation of the flat‐on lamellae from the amorphous state at a low degree of supercooling. A higher concentration of end group and cilium ion fragments, which are indicative of free chain ends, was observed on the edge‐on lamellar surfaces than on the amorphous and the flat‐on lamellar surfaces. This finding was attributed to the fact that the lateral surface of the edge‐on lamellae contains many growth fronts, leaving behind a large number of uncrystallized chain remnants on the surfaces. Structural disorder was facilitated on both edge‐on and flat‐on lamellar surfaces as the film thickness decreased. Hence, this PCA study offers new insights into the nonequilibrium nature of polymer crystals and the mechanism of polymer crystallization in thin and ultrathin films. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

12.
Wetting of a sessile droplet on structured or patterned surface can be found in a broad range of applications. The researchers have been promoted to keep working on the topic. The review is on the basis of the recent experimental advances on the sessile droplet wetting on the hydrophobic, hydrophilic, or combined hydrophobic and hydrophilic surfaces under isothermal conditions, and on heating or cooling substrates having nonisothermal conditions. More attention has been paid on the wetting configuration between the sessile droplet and the structured substrate; the research gap has been discussed on identifying the three-phase line shape. Further, the three-dimensional measurement for the sessile droplets on the patterned surfaces with focusing more on the contact line of sessile droplets might reveal new physical insights. This review targets at building a holistic overview on the sessile droplet wetting behaviors on the structured substrate in the past 2 years.  相似文献   

13.
(‒)-Cannabidiol (CBD) is one of the major phytocannabinoids extracted from the Cannabis genus. Its non-psychoactiveness and therapeutic potential, partly along with some anecdotal—if not scientific or clinical—evidence on the prevention and treatment of neurological diseases, have led researchers to investigate the biochemical actions of CBD on neural cells. This review summarizes the previously reported mechanistic studies of the CBD actions on primary neural cells at the in vitro cell-culture level. The neural cells are classified into neurons, microglia, astrocytes, oligodendrocytes, and neural stem cells, and the CBD effects on each cell type are described. After brief introduction on CBD and in vitro studies of CBD actions on neural cells, the neuroprotective capability of CBD on primary neurons with the suggested operating actions is discussed, followed by the reported CBD actions on glia and the CBD-induced regeneration from neural stem cells. A summary section gives a general overview of the biochemical actions of CBD on neural cells, with a future perspective. This review will provide a basic and fundamental, but crucial, insight on the mechanistic understanding of CBD actions on neural cells in the brain, at the molecular level, and the therapeutic potential of CBD in the prevention and treatment of neurological diseases, although to date, there seem to have been relatively limited research activities and reports on the cell culture-level, in vitro studies of CBD effects on primary neural cells.  相似文献   

14.
环取代基对金属化聚苯胺衍生物膜修饰电极性能的影响   总被引:1,自引:0,他引:1  
通过比较聚2,5-二甲氧基苯胺(PDMAn)、聚邻甲基苯胺(POT)和聚间氯苯胺(PmClAn)膜修饰电极的氧化还原电位、沉积在这3种聚合物上的铂微粒的表面形态与晶面取向以及异丙醇在分散Pt微粒的聚苯胺膜修饰电极上的氧化行为,从电子效应和立体效应探讨了聚合物电化学性质与环取代基的关系以及不同聚合基质对Pt沉积机理和有催化性能的影响,结果表明,在硫酸溶液中PDMAn膜修饰电极的氧化还原电位最负、POT次之、PmClAn最正,Pt在PDMAn和POT膜上的电沉积机理与在PmClAn膜上的不同,聚合物膜上沉积的Pt微粒呈现(200)晶面择优取向,其中POT膜上择优取向度最大,PDMAn次之,Pm-ClAn最小,异丙醇在金属化聚合物膜电极上的氧化电位取决于聚苯胺的本质,在POT膜修饰电极上异丙醇的电氧化主要发生在POT的活性电位区,而在PDMAn与PmClAn膜上的电氧化则主要发生在Pt上的氧化电位区,说明聚合物膜不仅作为Pt微粒的分散介质,而且本身有产生催化作用。  相似文献   

15.
Pyrene crystals were grown on carbon nanofibers (CNFs) by dispersing pyrene polycrystals and CNFs in water during ultrasonic irradiation, and they were characterized by scanning electron microscopy, X-ray diffractometry (XRD) and spectroscopy. The XRD measurements indicated that the orientation and size of the pyrene crystals on the CNF aggregates were different from that of the added pyrene polycrystals. Based on the spectroscopic properties of the pyrene crystals on the CNFs, the pyrene crystals on the CNF aggregates and on the individual CNFs were determined to be polycrystals and single crystals, respectively. These results indicate that pyrene crystals are produced on the CNFs by recrystallization of the added pyrene polycrystals and their crystal states depend on the aggregation state of the CNFs.  相似文献   

16.
陈海宝 《有机化学》1990,10(4):298-327
本文主要综述有机化学在建立核酸的顺序测定法和自动顺序仪,在破译遗传密码,在建立核酸片段的化学合成方法,固相合成法及DNA合成仪的设计,在合成许多有生物活力的核酸分子,在发展并完善遗传工程以及新近发现酶RNA(Ribozyme)等方面的卓越贡献。最后简要地展望有机化学将对生物学发展作出进一步贡献的几个方面。  相似文献   

17.
叙述了化学发光免疫分析的分类及特点,从发光底物、增强剂、过氧化物酶、过氧化物及其他方面,对鲁米诺类化合物化学发光酶免疫分析的进展进行了综述,引用文献34篇。  相似文献   

18.
4‐Nitrophenyl layers were grafted on gold and glassy carbon surfaces by electrochemical reductive adsorption of the corresponding diazonium salt. Electrochemical conversion efficiencies of 4‐nitrophenyl moieties to 4‐aminophenyl moieties on gold versus on glassy carbon in a protic medium were investigated using X‐ray photoelectron spectroscopy (XPS). In total contrast to all previous comparative studies showing greater electrochemical reactivity of aryl diazonium salt‐derived layers on gold than on glassy carbon, a much lower rate of conversion to 4‐aminophenyl was observed on gold than on glassy carbon by both cyclic voltammetry (CV) and chronoamperometry (CA) methods. The lower electron transfer rate during conversion observed on gold versus glassy carbon was proposed to be due to a mechanism related to the molecular structure rearrangement of 4‐nitrophenyl during the process on glassy carbon. However, whilst complete conversion of 4‐nitrophenyl to 4‐aminophenyl on gold by chronoamperometry was achieved, on glassy carbon complete reduction could not be achieved under the same conditions.  相似文献   

19.
A critical review on the effect of ultrasound (US) on enzymes and their biocatalytic action is presented here. Discussion on the information users of US acquire before utilizing the different devices, and the importance they give to US frequency is constant along the review. The authors have gone into the different areas in which the US–enzyme binomial has been applied. The lack of enough information on the US–enzyme-working conditions under which each piece of research has been developed, and the necessity to provide complete information on the data and metadata to give enough light on each piece of research (and thus on the potential comparison of results from different studies) are critically exposed. With this aim, the study has been divided into the positive effect of US on enzymes to favor the production of metabolites, polymers or proteins; and the degradation, inhibition or activation of the biocatalyst under US application. Also the effect of US on enzyme production and the main fields of application of the US–enzyme binomial are discussed.  相似文献   

20.
综述了多相聚合物体系相界面的形成、界面层状态的表征、界面层性质及其对体系性能的影响。重点论述了不同类型增容剂对界面行为的影响,其中对嵌段型增容剂的分子量、浓度等因素对界面行为的影响建立了定量关系;而对接枝型和无规增容剂对界面行为的影响研究较少,有待发展。指出了在界面张力、界面层厚度与多相聚合物体系性能,尤其是力学性能之间建立量化关系是高分子物理领域一个可以期待的发展方向。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号