期刊文献+
共找到14篇文章
< 1 >
每页显示 20 50 100
基于认知模型建构的问题式教学--以“有机物制备”为例 被引量:1
1
作者 徐志锴 《化学教与学(下半月)》 2021年第2期2-5,17,共5页
通过对课程标准、教材内容和高考题的深入分析,发现学生常常忽视有机物制备中装置选择、产品分离和结构鉴定的重要性,因而精心设计了“分析情景,初建模型--再现情景,精修模型--陌生情景,应用模型”三个教学环节,让学生在问题解决中逐渐... 通过对课程标准、教材内容和高考题的深入分析,发现学生常常忽视有机物制备中装置选择、产品分离和结构鉴定的重要性,因而精心设计了“分析情景,初建模型--再现情景,精修模型--陌生情景,应用模型”三个教学环节,让学生在问题解决中逐渐建构有机物制备的一般认知模型,提升“模型认知”核心素养。 展开更多
关键词 认知模型 问题式教学 有机物制备
下载PDF
基于学科核心素养的“教、学、评”一体化评析——以“高三有机物制备实验复习课”为例
2
作者 周李玮 《中学化学教学参考》 2024年第29期62-64,共3页
对有机物制备实验复习课“教、学、评”一体化进行思辨性分析和教学改进,以期更好地促进学生化学学科核心素养的发展。
关键词 “教、学、评”一体化 有机物制备实验复习 评析
下载PDF
基于单元设计的“液态有机物制备”教学实践
3
作者 黄炎维 《中学化学教学参考》 2019年第7期17-20,共4页
单元设计是一种有效的途径。将分散在不同学习章节的内容统一在“液态有机物制备”主题之下,以学生的认知过程为基础,分析、归纳出“液态有机物制备”的知识要素,在单元教学中通过在数据分析、证据推理中建构“液态有机物制备”的认知模... 单元设计是一种有效的途径。将分散在不同学习章节的内容统一在“液态有机物制备”主题之下,以学生的认知过程为基础,分析、归纳出“液态有机物制备”的知识要素,在单元教学中通过在数据分析、证据推理中建构“液态有机物制备”的认知模型;通过演示实验、学生实验、科学探究等教学活动,优化认知模型。最终形成有助于“液态有机物制备”问题解决的一般思路,促进学生化学核心素养的发展。 展开更多
关键词 液态有机物制备 单元教学设计 一般思路 认知模型
原文传递
化学综合实验题解题策略
4
作者 刘西广 《数理化解题研究》 2024年第13期143-145,共3页
化学综合实验题是高考每年必考题型,但是每年的考查方向又有所不同.本文从3个方面剖析常见的3种类型,助力教师的教学和学生的学习.
关键词 化学综合实验题 有机物制备及分离 实验探究 实验方案设计
下载PDF
基于“任务驱动”优化教学设计的课例研究——以“乙酸乙酯的制取”新授课为例 被引量:1
5
作者 王瑶 《化学教学》 CAS 北大核心 2016年第7期35-38,共4页
通过“任务驱动”进行“乙酸乙酯的制取”的教学设计,把任务分解为思考酯化反应的特点、选择酯化反应条件和装置设计系列任务。教学实践表明,“任务驱动”有利于提高学生实验设计能力和创新能力,让学生体会到知识的实践意义;使用“任务... 通过“任务驱动”进行“乙酸乙酯的制取”的教学设计,把任务分解为思考酯化反应的特点、选择酯化反应条件和装置设计系列任务。教学实践表明,“任务驱动”有利于提高学生实验设计能力和创新能力,让学生体会到知识的实践意义;使用“任务驱动”教学模式时,需要根据学生的知能基础把主任务分解成适当的任务系列;必须坚持以学生为主体,激发他们的积极思维,发挥主动性和创造性,同时教师也要起好引导和辅助作用。 展开更多
关键词 任务驱动 乙酸乙酯的制取 有机物制备实验教学 教学设计 课例研究
下载PDF
Study on an Organic Hybrid Made from Chlorinated Polyethylene and 2,2'-methylene-bis- (4-methyl-6-cyclohexylphenol) 被引量:2
6
作者 刘继涛 李玮茹 +1 位作者 俞建勇 王善元 《Journal of Donghua University(English Edition)》 EI CAS 2003年第2期31-35,共5页
The dynamic mechanical properties and miscibility of an organic hybrid made from chlorinated polyethylene (CPE) and 2, 2'-methyIene-bis-( 4-methyl-6-cyclohexylphenol) ( ZKF ) are mainly discussed in this paper. It... The dynamic mechanical properties and miscibility of an organic hybrid made from chlorinated polyethylene (CPE) and 2, 2'-methyIene-bis-( 4-methyl-6-cyclohexylphenol) ( ZKF ) are mainly discussed in this paper. It is found that ZKF acts as an antiplasticizer in CPE matrix and has good miscibility even with large ratio in CPE /ZKF hybrids. The glass transition temperature of various CPE /ZKF hybrids determined by DSC give a good fit to Wood's equation. Bifunctional ZKF is supposed to improve the intermolecular force of CPE, and the improvement is developed when the ZKF content increases. On the other hand, the viscoelastic properties are highly improved with the addition of ZKF. TA and tanδ peak values increase when the ZKF content increase in the CPE /ZKF hybrids, the damping capacity has been improved during the glass transition of CPE /ZKF hybrids. In addition, the glass transition temperature shifts to room temperature from the low temperature with the continuous addition of ZKF to CPE. 展开更多
关键词 CPE hybrid VISCOELASTIC DAMPING glass transition antiplasticizer
下载PDF
Preparation of Ti/PTFE-F-PbO2 Electrode with a Long Life from the Sulfamic Acid Bath and Its Application in Organic Degradation 被引量:5
7
作者 洪夏萍 张蓉 +1 位作者 童少平 马淳安 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第6期1033-1038,共6页
A polytetrafluoroethylene (PTFE)-doped PbO2 electrode on a Ti substrate was prepared by galvanostatic method from the sulfamic acid bath (Ti/PTFE-F-PbO2-I) or nitric acid bath (Ti/PTFE-F-PbO2-II). Scanning Elect... A polytetrafluoroethylene (PTFE)-doped PbO2 electrode on a Ti substrate was prepared by galvanostatic method from the sulfamic acid bath (Ti/PTFE-F-PbO2-I) or nitric acid bath (Ti/PTFE-F-PbO2-II). Scanning Electron Microscopy revealed that the Ti/PTFE-PbO2-I electrode had a more regular morphology with smaller size crystals than the Ti/PTFE-F-PbO2-II electrode. On the basis of the results of both the accelerated electrolysis test and the empirical formula for estimating the service life of an electrode, the service life of the Ti/PTFE-PbO2-I electrode was predicted to be more than 7 years under conventional electrolysis conditions (0.1 A·cm^-2). During the treatment of 4-chlorophenol-contaminated water, the Ti/PTFE-PbO2-I anode showed both a good electro-catalytic activity and high electrochemical stability, exhibiting an excellent potential application. 展开更多
关键词 lead dioxide sulfamic acid electrochemical oxidation 4-CHLOROPHENOL
下载PDF
Research on Preparation Method of Static Head Space for Volatile Organic Compounds in Drinking Water 被引量:3
8
作者 Yan GUO 《Agricultural Science & Technology》 CAS 2015年第4期836-839,共4页
[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds i... [Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds in drinking water. [Method]The preparation method of head space was adopted for the volatile organic compounds in drinking water. [Result] The 20 kinds of volatile organic compounds in drinking water all could be detected simultaneously by using HS-GC-FID method,and they all could be separated well. The HS-GC-FID method could analyze the detected substances qualitatively and quantitatively. In addition, this detection method was characterized by larger linear range of concentration, higher precision, higher detection limit and higher recovery rate. [Conclusion] Under certain conditions, HSGC can reduce the loss of volatile organic compound in drinking water and improve the sensitivity of detection. Moreover, the detection results meet the requirements by quality control. 展开更多
关键词 Headspace gas chromatography Volatile organic compounds Drinkingwater
下载PDF
Preparation and Characterization of Hybrid Aqueous Dispersions Composed of Silica Sol and Poly(styrene-co-acrylate) 被引量:4
9
作者 黄福明 张国伟 +1 位作者 胡春圃 应圣康 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第6期816-823,共8页
A stable silica sol with 3-5 nm in diameter, which can form homogeneous film without crack, was prepared and characterized. Then, the inorganic-organic hybrid aqueous dispersion composed of such a silica sol and an em... A stable silica sol with 3-5 nm in diameter, which can form homogeneous film without crack, was prepared and characterized. Then, the inorganic-organic hybrid aqueous dispersion composed of such a silica sol and an emulsion of styrene (St) and acrylate (Ac) copolymer was prepared and the hybrid effect between the silica sol and poly(St-co-Ac) was observed by Fourier transform infra-red (FT-IR) spectroscope. The toughness of the film prepared by this kind of hybrid aqueous dispersion was excellent, as it was enhanced appreciably by commixing with a small amount of poly(St-co-Ac) emulsion. Some amino-polysiloxane modified hybrid aqueous dispersions were also prepared and the properties of the modified dispersions and their films were investigated. The experimental results showed that the film prepared with such an amino-polysiloxane modified hybrid dispersion exhibited excellent hydrophobicity and low surface energy after heat treatment for 1.5 h, during which the formation of the graft copolymer was observed. The surface energy of this film decreases as a result of the enrichment of siloxane segments on the film surface. 展开更多
关键词 silica sol COPOLYMER aqueous dispersion inorganic-organic hybrid amino-polysiloxane
下载PDF
Preparation of Thin Film Composite Nanofiltration Membrane by Interfacial Polymerization with 3,5-Diaminobenzoylpiperazine and Trimesoyl Chloride 被引量:2
10
作者 王丽红 李德玲 +2 位作者 程丽华 张林 陈欢林 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第2期262-266,共5页
A new aromatic diamine,3,5-diaminobenzoylpiperazine (3,5-DABP),was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3... A new aromatic diamine,3,5-diaminobenzoylpiperazine (3,5-DABP),was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3,5-DABP as aqueous monomer and trimesoyl chloride (TMC) as organic monomer,thin film composite (TFC) nanofiltration membranes were prepared by interfacial polymerization technology.The salt rejection order of these TFC membranes is Na2SO4MgSO4MgCl2NaCl.This sequence indicates that the membranes are negatively charged. 展开更多
关键词 thin film composite membrane 3 5-diaminobenzoylpiperazine trimesoyl chloride interfacial polymerization
下载PDF
Preparation process and characterization of new Pt/stainless steel wire mesh catalyst designed for volatile organic compounds elimination 被引量:1
11
作者 张婷 陈敏 +1 位作者 高园园 郑小明 《Journal of Central South University》 SCIE EI CAS 2012年第2期319-323,共5页
A novel 0.1% Pd-0.05% (mass fraction) Pt/stainless steel wire mesh catalyst was prepared for volatile organic compounds (VOCs) elimination. The catalyst was synthesized by stainless steel wire mesh as support and ... A novel 0.1% Pd-0.05% (mass fraction) Pt/stainless steel wire mesh catalyst was prepared for volatile organic compounds (VOCs) elimination. The catalyst was synthesized by stainless steel wire mesh as support and then treated by anodic oxidation technology to develop a porous membrane on the support. During the anodic oxidation process, various electrolytes were used to investigate the formation of porous membrane. And the catalytic performance of the catalysts was tested by using toluene and acetone combustion as model reaction. The temperatures of complete toluene and acetone conversion were decreased to 180℃ and 240 ℃, respectively. The morphologies of the stainless steel wire mesh supports and catalysts were characterized by means of scanning electron microscopy (SEM) and temperature-programmed reduction (TPR). 展开更多
关键词 volatile organic compounds anodic oxidation ELECTROLYTE PD
下载PDF
Preparation of Uranyl Complexes with Sugars
12
作者 Aibassov Erkin Zhakenovich Kenzhaliev Bagdaulet Kenzhalievich Tussupbaev Nessipbay Kuandykovich Berkinbaeva Ainura Chukmanova Marzhan Iskhakova Renata Bulenbayev Maxat Zhumabaevich 《Journal of Chemistry and Chemical Engineering》 2014年第6期641-646,共6页
We first received and examined X-ray and IR (infra red) spectroscopy of uranium complexes with sugars. We proposed a method for direct synthesis of complex organic compounds, uranium chloride UO2Cl2 with various sug... We first received and examined X-ray and IR (infra red) spectroscopy of uranium complexes with sugars. We proposed a method for direct synthesis of complex organic compounds, uranium chloride UO2Cl2 with various sugars (D-glucose, D (+) maltose, D-sucrose, D-lactose and the polysaccharide Dextran) as potential precursors for the treatment of cancer diseases. 展开更多
关键词 Uranyl complexes X-ray and IR spectroscopy sugars.
下载PDF
Preparation of Organic Selenocystine Using Locally Isolated Bread Yeast
13
作者 Fouad Houssein Kamel 《Journal of Life Sciences》 2013年第1期57-62,共6页
In contrast to the toxic inorganic forms of selenium to life at very low concentrations, the organic-selenium compounds are of considerable interest and several of them play essential roles in cell biochemistry and nu... In contrast to the toxic inorganic forms of selenium to life at very low concentrations, the organic-selenium compounds are of considerable interest and several of them play essential roles in cell biochemistry and nutritional science. Se-yeast (Selenium-enriched yeast) is a common form of selenium used to supplement dietary intake of this important trace mineral. In the present study, we tried to prepare an organic selenocystine using locally isolated bread yeast (Saccharomyces cerevisiae). A novel locally prepared date extract media enriched by addition of 0.2% KH2PO4 (potassium phosphate), 0.6% ammonium sulfate was adopted as alternative culture media. Differences concentrations of selenium salt (30, 60, 120 and 240 lag/mL) were added to the yeast culture media. While the best concentration of selenium added was 30Bg/mL, it achieved optimal conditions for the growth of yeast and the production of red yeast growth identical to the standard. The products (organic selenocystine) were analyzed by HPLC (High Performance Liquid Chromatography) and AAS (Atomic Absorption Spectrophotometer) comparing with authentic standard obtained from Sigma. Results confirmed the formation of similar selenocystine products. 展开更多
关键词 Organic selenocystine selenium deficiency bread yeast selenium yeast.
下载PDF
建模教学在发展高阶思维中的研究--以“乙酸乙酯的制备”复习为例 被引量:2
14
作者 曾洁萍 李金燕 +1 位作者 许旋 罗一帆 《中学化学教学参考》 2022年第7期45-46,共2页
以“乙酸乙酯的制备”为原型,从知识原点出发,通过“快出产品”“多出产品”“出好产品”等角度建构有机物的制备模型,在解决陌生有机物制备问题时进行情境关联、分析评价、系统探究,实现认识问题视角的转变,发展学生的高阶思维能力。
关键词 有机物制备模型 乙酸乙酯 高阶思维
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部