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1.
严世强 《大学化学》2006,21(3):8-10
以建构主义学习理论为指导,以现代教育技术为手段,以实施学习环境设计为核心,以有效发挥学生学习的主动性、积极性、创造性和提高教学质量为目标,通过多媒体技术与现代教学模式、方法和思想的有机结合,开发以研究性教学为背景的化工基础多媒体课件,初步实现了化工基础课程教学方法和手段的创新以及教学过程和内容的优化。  相似文献   

2.
本文根据现代教学理论和学生认知心理特点,试图通过对以教师为中心和以学生为中心,由此而发展出的教法和学法对比,阐明在以培养创新能力为核心的素质教育的情况下,重新探讨课堂教学并构建一种新型的师生关系,有其时代必要性。  相似文献   

3.
针对医学基础化学教学过程中存在的问题,基于"以学生为中心""以产出为导向"的教学理念,围绕培养目标和毕业要求,从课程内容组织、教学内容更新、教学模式改革等方面进行了系统设计和实践,注重教学内容与医学知识的融合,充分调动了学生学习的主动性和积极性,提高了学生的科学素养和发展能力,以更好地服务于高素质领军型医学人才的培养。  相似文献   

4.
以过渡态理论为基础,以羧肽酶A(CPA)的天然肽底物马脲酰-苯丙氨酸为模型,分别以磷原子和硫原子为四面体过渡态类似物的中心原子来设计和合成了半抗原和全抗原,将两类抗原用免疫方法诱导制备出抗体,然后对两类抗体水解肽键的活性进行比较。  相似文献   

5.
丁基橡胶的发展现状及发展建议   总被引:1,自引:0,他引:1  
丁基橡胶具有突出的气密性和水密性、良好的化学稳定性和热稳定性,主要用于制造各种车辆轮胎的内胎,是高性能子午胎的首选材料。依据分子结构,丁基橡胶分为普通丁基橡胶和卤化丁基橡胶,本文详细介绍了普通丁基橡胶和卤化丁基橡胶的生产方法,对目前主要的溶液法和淤浆法两种工艺技术经济指标进行总结比较,分析了国内外的生产现状和市场需求,对我国丁基橡胶的发展提出的建议是以淤浆法工艺为主流、以卤化丁基橡胶产品为趋势、以新产品的开发为重点及加快国内工程技术开发,以满足日益增长的市场需求。  相似文献   

6.
探讨本科生与研究生环境化学课程教学内容和模式上的差异,提出本科生教学以传授基础理论为主,以污染事件为切入点,强调系统性、趣味性和特色性,采用问题教学法、案例教学法和视频教学法等方法;而研究生教学以归纳总结知识点为主,关注研究热点和前沿问题,强调衔接性、主动性和应用性,采用互动教学法、体验教学法、文献归纳法等方法。  相似文献   

7.
辅酶催化安息香缩合反应的实验探讨   总被引:1,自引:0,他引:1  
以苯甲醛为原料,以辅酶为催化剂和以四丁基溴化铵为相转移催化剂,经过安息香缩合反应制备二苯羟乙酮。  相似文献   

8.
含氨基聚甲基丙烯酸羟乙酯树脂对胆红素的吸附性能研究   总被引:15,自引:3,他引:12  
以交联聚甲基丙烯酸羟乙酯树脂为载体,以己二胺和多乙烯多胺为功能基制备了一系列胆红素吸附剂,研究了它们在不同吸附温度、离子强度和胆红素浓度等条件下,对胆红素的吸附性能的影响.研究表明,该类吸附剂对胆红素具有良好的吸附性能,其中以己二胺和质子化己二胺为功能基的吸附剂对胆红素的吸附作用最佳.  相似文献   

9.
铈及氟铈联用对CaHPO4·2H2O在水溶液中的转化产物的影响   总被引:1,自引:1,他引:0  
《中国稀土学报》2001,19(4):316-319
以XRD和IR为表征手段,以恒pH法为溶解实验方法,研究了37℃下以铈单独处理和氟铈联用处理对二水磷酸氢钙(CaHPO4·  相似文献   

10.
刘岩 《化学教育》2014,35(23):40-43
针对当前区域教研存在的问题,阐述了"小分队视导"这一新型教研方式的工作特点和以问题为核心、以课例为载体、以名师为示范、以反思为宗旨、以"教学新时空"为平台、以反馈为手段,来促进化学教师专业发展的实践与思考.  相似文献   

11.
利用手持技术改进测定乙醇分子结构实验   总被引:1,自引:0,他引:1  
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。  相似文献   

12.
13.
由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。  相似文献   

14.
The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.  相似文献   

15.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

16.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

17.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

18.
实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。  相似文献   

19.
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.  相似文献   

20.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

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