共查询到20条相似文献,搜索用时 965 毫秒
1.
第三次全国教育工作会议对我们教育工作者提出了更高的要求。如何在中学化学教学中对学生实施创新思维、创新精神和能力的教育是摆在中学化学教师面前的重要课题。中学化学教授的内容是化学的基础知识 ,而这些基础知识又都是前人经过探索并已验证过的真理 ,学生在学习时不会有多少的发明和创新。关键在于组织学生认知这些知识的过程中 ,应注意培养学生的创造性思维能力。化学学科的特点之一是以实验为基础 ,而现行中学化学教材中的实验又多为一些验证性实验。分组实验时 ,通过课本知识的学习 ,反应原理和现实已知的 ,犹如照方拿药 ,整个过程… 相似文献
2.
对甘肃甘南藏族自治州中学化学藏汉双语教学现状进行调查研究,总结了在双语教学模式推进和功能体现等方面取得的成效,分析了存在的问题。化学教师双语教学能力需要提高;藏族学生的化学学习策略和学习方法制约着化学学习能力的提升;藏族中学所用化学教材对藏族学生而言难度较大,远离学生的成长环境和生活境遇,学习资源缺乏,使藏族学生遭遇语言经验和知识理解的双重难度;藏族中学化学实验条件和教师实验教学技能影响了实验教学的有效开展。由此提出促进化学藏汉双语教学的策略建议,以提升藏族学生的科学素养,培养“民汉兼通”的理科人才。 相似文献
3.
化学研究性学习应以课堂教学为主阵地,在中学化学教学中,充分利用化学学科"以实验为基础"的基本特征,挖掘和开发化学实验在研究性学习中的功能,对于改变学生的学习方法,形成终身学习的能力,培养科学探究能力具有重要的意义。对化学课堂中如何利用实验教学开展研究性学习从几个方面进行了探讨。 相似文献
4.
化学教学的主旨是通过教学把人类已有的化学科学知识变成学生自己的知识,并进一步转化为学生发现、探究和解决新问题的能力。要十分注重中学化学实验的教育功能,重视化学实验及化学实验教学的设计,以培养学生的化学实践能力和创新精神。新一轮课程改革要求在教学中强化实验的功能,改变以往实验只是起演示和辅助作用的状况;在学生探究实验中,必须注意激发学生的兴趣,注重培养学生的创新意识、实验能力、科学方法和合作精神。 相似文献
5.
高中学生面临着高考升学与提高自身综合素质两大任务。在中学化学教学中,如何使两者有效结合,是我们化学教师始终关心的一个现实问题。化学实验在化学中占有重要地位,对培养学生综合能力有着不可替代的作用。但由于许多原因(如教材的编写体系、教师队伍建设、教学条件以及高考模式等),高中化学实验一直是教学环节中一个薄弱环节,也是学生在考试中失分较严重的部分。部分学生高中毕业之后,在日常生活中不能独立运用化学实验技能解决常见问题,更谈不上自主设计实验、自主研究等较高要求了。笔者在从事高中化学教学的同时,兼任环境监测选修课的教学,在教学过程中,经常思考这个问题:能否通过选修课培养学生对化学实验的强烈兴趣,加强实验技术的掌握和应用,让学生在学习环保知识的同时,能全面提升他们的化学实验综合能力。 相似文献
6.
7.
中学化学实验是中学化学教学的重点内容,是培养学生学习化学知识、形成实验技能,提高综合应用能力的基本途径。 相似文献
8.
9.
化学假说在中学化学教学中的运用 总被引:2,自引:0,他引:2
中学化学教学的主要目标之一是让学生掌握基础化学知识的同时掌握化学知识形成的方法——化学科学研究方法.只有掌握化学科学的一般方法,学生才能自如地、不受限制地进行思维,从而将知识学深学透,形成化学学习的能力,发展学生的创造能力. 相似文献
10.
11.
12.
13.
Reactions in droplets in microfluidic channels 总被引:5,自引:0,他引:5
Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights. 相似文献
14.
The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (Asi). In order to document the methylation process in humans, the kinetics of Asi, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of Asi. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As2O3) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of Asi metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of Asi uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems. 相似文献
15.
16.
Electrochemistry is one of the most advanced techniques for monitoring neurochemical activities in the living brain because electrochemical approaches bear the advantageous features of high spatial and temporal resolutions, which facilitate its tremendous potential in investigating the highly spatially heterogeneous brain system and the fast dynamics of neurochemical activities. On the other hand, since brain is the most complicated organ in the sense of its numerous kinds of neurochemical species, high selectivity is always required for any analytical methods that approach the brain. In this review, we will discuss various electrochemical methodologies to achieve selective detection of neurochemicals in mammalian brain and the strategies developed mainly by our group towards selective monitoring of both electrochemically active and inactive neurochemicals. At the end, we will discuss possible solutions towards brain mapping of neurochemical species and combination of neurochemical detection strategy with electrophysiology as the direction of future development of electroanalysis in living brain. 相似文献
17.
18.
G. den Boef 《Fresenius' Journal of Analytical Chemistry》1981,305(2):127-129
Summary At the session of the WPAC of Fechem on education in analytical chemistry it was concluded that it is now essential to include chemometrics and basic knowledge of computers in all courses on analytical chemistry.
Tendenzen in der analytisch-chemischen Ausbildung
Zusammenfassung Bei einer Tagung der WPAC über die Lehre auf dem Gebiet der analytischen Chemie wurde bei der Betrachtung neuer Aspekte festgestellt, daß vor allem Chemometrie und Grundkenntnisse in Computertechnik in die Ausbildung aufgenommen werden sollten.相似文献
19.
20.
Ke Min Wojciech Jakubowski Krzysztof Matyjaszewski 《Macromolecular rapid communications》2006,27(8):594-598
Summary: The recently developed initiation system, activators generated by electron transfer (AGET), is used in atom transfer radical polymerization (ATRP) in the presence of a limited amount of air. Ascorbic acid and tin(II ) 2‐ethylhexanoate are used as reducing agents in miniemulsion and bulk, respectively. An excess of reducing agent consumes the oxygen present in the system and, therefore, provides a deoxygenated environment for ATRP. ATRP of butyl acrylate is successfully carried out in miniemulsion and in the presence of air. During polymerization the radical concentration remains constant. The polymerization reaches over 60% monomer conversion after 6 h, which results in polymers with a predetermined molecular weight = 14 000 g · mol−1 and a low polydispersity ( = 1.23). AGET ATRP of styrene is also successful in bulk in the presence of air, as evidenced by linear semi‐logarithmic kinetics, which leads to polystyrene with an of 13 400 g · mol−1 and a low polydispersity index ( = 1.14).