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1.
设计了一款在线化学实验安全考试系统,系统包括在线考试、数据分析等模块。利用此系统可以完成化学实验安全培训和考核。利用数据学习算法对学生考试结果进行了数据分析,评价了学生对安全知识的掌握情况,保证了实验课程的安全进行,能为实验教学提供有效帮助。  相似文献   

2.
关于分析化学实验课程考试改革的设想   总被引:4,自引:0,他引:4  
针对分析化学实验课程的特点,改变传统的单纯笔试或操作考试方法,提出了“设计答辩与操作相结合,加平时成绩”的考试方法。此方法具有公正、客观、合理、易于操作等特点,有利于全面考察学生分析问题和解决问题的能力。  相似文献   

3.
刘文明 《化学教育》2013,34(3):53-54
以基础元素"化学实验考试改革"一例,呈现了案例中蕴含的化学实验考试改革理念、方法和技巧,指出了过去的"化学实验考试"存在的缺陷和改革后的"化学实验考试"所具有的创新点,推荐了一种关于基础元素"化学实验技能考试"的新模式。  相似文献   

4.
陈联群 《大学化学》2005,20(5):17-19
讨论在物理化学实验课中实行设计实验考试的有关问题和实践。  相似文献   

5.
翟志勇  金前英 《化学教育》2006,27(12):42-45
多年来上海市实验操作考试的实际情况表明,考生和老师对这项举措并不满意,操作考试的效果并不理想。为此,本文提出了3点建议:将实验操作考试纳入学校常规考试中,实施可操作性实验操作考试量化考核表,以及建立学生实验档案袋制度。  相似文献   

6.
在移动互联网的飞速发展与智能手机等移动终端日趋普及的情况下,设计开发了基于移动端的基础化学原理实验在线学习与考试系统。该系统包括化学实验室安全教育与考试、实验基础理论学习、试题库资源、移动端在线考试、成绩管理和统计分析等五大功能。该系统的开发建设顺应了"互联网+教育"的发展趋势,有利于学生自主学习,节约考试资源。  相似文献   

7.
刘文明 《化学教育》2014,35(2):31-32
指出了传统“化学实验考试”存在的不足,以案例的形式分析了化学实验考试改革理念、方法、技巧和创新点,推荐了一种“无机化学实验考试”的新模式。  相似文献   

8.
孙黎颖  张国华 《化学教育》2018,39(19):47-51
“探究浓度对化学反应速率的影响”是中外高中典型的基础实验。实验内容类似,但教学方法大相径庭。我国侧重以实验结论学习化学原理。英美国家注重实验的过程和方法:设计控制变量,绘图,统计分析数据,注重后实验过程,考试评估巩固实验教学的行为过程。  相似文献   

9.
叶晨  张文华 《化学教育》2010,31(6):90-92
介绍了GCE A-Level化学实验考试的制度、要求、内容,对部分试题进行了详细地评析,分析了GCE A-Level化学实验考试制度对于我国化学新课程改革的借鉴意义。  相似文献   

10.
通过设计开发有机化学实验课程在线测试与学习平台改进有机化学实验教学。平台基于开源考试系统设计开发,可自适应多种终端和操作系统,无需单独安装客户端。构建符合有机化学实验教学目标和需求的实验能力评测指标体系,并在此基础上搭建平台、建设标准化试题库和教学资源库。平台除了具备考试系统的基本功能外,还可以根据测试结果推送相关学习资源,实现个性化精准教学。实践证明,平台可以帮助学生掌握实验知识,帮助教师了解教学效果。  相似文献   

11.
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   

12.
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   

13.

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   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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