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“中学化学实验研究”课程绿色化设计的思考 总被引:1,自引:0,他引:1
当前我国高等师范院校化学专业的"中学化学实验研究"课程应从化学实验的绿色化设计、规范微型化学实验和实施化学实验绿色化技术3个方面进行深入开发和推广,以利于《普通高中化学课程标准(实验)》的贯彻和实施。 相似文献
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《普通高中化学课程标准(实验)》明确指出“转变学生的学习方式是课程改革的基本要求。教师要更新教学观念,在教学中引导学生进行自主学习、探究学习和合作学习,帮助学生形成终身学习的意识和能力。”针对《化学与生活》选修模块中“活动.探究”、“动手空间”、“角色扮演”、“学以致用”等活动性栏目功能和特点的不同,在教学中采取了不同的教学策略,促进了学生的自主学习、探究学习及合作学习。 相似文献
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正基于《普通高中化学课程标准(2017年版)》编写的人教版教材《化学(必修第2册)》和选择性必修1《化学反应原理》,称为新教材;人教版《普通高中课程标准实验教科书:化学2(必修)》《普通高中课程标准实验教科书:化学反应原理(选修4)》,称为老教材。1 新老教材中"化学平衡"内容的比较(1)章引言:老教材仅指出本章的学习内容并说明了局限性,但对于学习目的、意义等描述很模糊,教学指导性不大;新教材章引言进行了凝练和概括,明确了本章 相似文献
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《普通高中化学课程标准(实验)》有多处特别强调化学教学应注意“化学模型”的制作和运用。本文通过尝试让学生自制化学模型,并探索在化学教学中如何充分发挥化学模型的教育功能,以培养学生创新能力和空间想象能力。实践中收到了较明显的教学效果。 相似文献
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浅谈新课程标准下高三化学复习模式的构建 总被引:2,自引:0,他引:2
2003年3月,教育部颁发了《普通高中化学课程标准(实验)》。课程标准立足于学生科学素养的培养,着眼于学生未来的发展,体现了高中化学课程的时代性、基础性与选择性。笔者以新的化学课程标准作指导,在构建高三化学复习新模式方面作了初步尝试,收到了显著效果。1立足基础着眼应用 相似文献
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本文以课程改革的理念和新课程观为指导,对人教版《普通高中课程标准实验教科书·化学(必修)》的体系结构和栏目设计做了分析和讨论。 相似文献
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本文主要谈谈普通高中课程标准实验教科书·《化学1 (必修) 》(人民教育出版社出版) 第三章“金属及其化合物”的教学设计。 相似文献
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人民教育出版社出版的普通高中课程标准实验教科书《化学1 (必修) 》和《化学2 (必修) 》中,在实验教学方面体现新课改精神之处甚多,开辟了“科学探究”、“实践活动”等栏目,对学生进行素质教育,培养其主动学习能力起到了很大作用。教材还针对以往高中教材中某些难以完成的实验作了一些改进。但是在几则实验安排上,仍存在一定问题,为更好的实施新课程,特做分析并提出建议如下。 相似文献
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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
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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
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A. P. Grimanis N. Kalogeropoulos V. Kilikoglou M. Vassilaki-Grimani 《Journal of Radioanalytical and Nuclear Chemistry》1997,219(2):177-185
Neutron activation analysis (NAA) is a very sensitive and accurate multielement analytical method that is widely applied to the investigation of environmental and archaeological problems. The first part of this paper is a review of pollution studies of toxic trace elements in sediments, seawater and marine organisms of Saronikos Gulf, Greece by NAA. The second part of this paper is a review of provenance studies based on minor and trace element research in ancient ceramics, obsidian, flint, limestone, marble and lead by Instrumental NAA, performed at the NCSR Demokritos. 相似文献
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In situ generation of reactive species within confined geometries, such as nanopores or nanochannels is of significant interest in overcoming mass transport limitations in chemical reactivity. Solvent electrolysis is a simple process that can readily be coupled to nanochannels for the electrochemical generation of reactive species, such as H(2). Here the production of hydrogen-rich liquid volumes within nanofluidic structures, without bubble nucleation or nanochannel occlusion, is explored both experimentally and by modeling. Devices comprised of multiple horizontal nanochannels intersecting planar working and quasi-reference electrodes were constructed and used to study the effects of confinement and reduced working volume on the electrochemical reduction of H(2)O to H(2) and OH(-). H(2) production in the nanochannel-embedded electrode reactor output was monitored by fluorescence emission of fluorescein, which exhibits a pH-dependent emission intensity. Initially, the fluorescein solution was buffered to pH 6.0 prior to stepping the potential cathodic of E(0)' for the generation of OH(-) and H(2). Because the electrochemical products are obtained in a 2:1 stoichiometry, local measurements of pH during and after the cathodic potential steps can be converted into H(2) production rates. Independent experimental estimates of the local H(2) concentration were then obtained from the spatiotemporal fluorescence behavior and current measurements, and these were compared with finite element simulations accounting for electrolysis and subsequent convection and diffusion within the confined geometry. Local dissolved H(2) concentrations were correlated to partial pressures through Henry's Law and values as large as 8.3 atm were obtained at the most negative potential steps. The downstream availability of electrolytically produced H(2) in nanochannels is evaluated in terms of its possible use as a downstream reducing reagent. The results obtained here indicate that H(2) can easily reach saturation concentrations at modest overpotentials. 相似文献
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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
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