不同版本选修新教材中化学平衡内容的比较研究——以人教版和鲁科版为例

正以"化学平衡"这一内容为例,比较2019年人教版和鲁科版高中化学选修新教材,为一线教师的教学提供参考性建议。1 人教版、鲁科版选修教材中化学平衡的内容比较(1)内容选择:鲁科版侧重运用Q与K的相对大小进行定量判定,适用面广,精确性高。人教版则体现定性、定量分析的双重视角。其次,鲁科版的知识点呈现全面完整,让学生一目了然。人教版的知识点呈现简明扼要,给予师生灵活选择、处理知识的空间。(2)组织编排:     

新旧高中化学人教版教材的对比研究——以氯元素为例

对2版教材中氯元素知识点的编排与呈现方式进行了系统整理与比较,相同点是新旧教材对氯气的基本性质的内容编排基本一致,也都体现了宏观与符号表征的思维;不同点在于章节编排顺序,教材标题内容,氯气的物理性质,氯气的实验室制法,氯气与非金属单质反应的内容呈现,次氯酸的相关内容,氯气的用途,氯离子的检验以及对“卤素元素”的探讨。     

我国现行“鲁科版”高中化学教材研究现状分析

山东科学技术出版社出版的《普通高中课程标准实验教科书·化学》,即“鲁科版”高中化学教材已经在我国4个省实验区,就中学化学教师和研究者对该套教材的内容评价和使用情况进行了综述和分析,其中包括教材编排体系、教材难度广度评价、实验内容、教材“栏目”和插图设计以及习题的呈现等几个主题。结果表明大多数教师和研究者认可该套教材的编排体系和内容设计,不过实施中也出现了一些问题,例如教材内容涉及知识范围较宽,实验设计安全性还需加强,插图缺乏吸引力,习题难度较大等。     

美国高中化学教材中的实验设计

从内容的编排及其设计特点2个方面对美国新版高中化学教材“CHEMISTRY：Conceptsand Application”（《化学：概念与应用》）的实验体系进行了介绍和分析。     

支撑自主建构强化能力形成——韩国高中化学教材化学热力学内容编排的启示

化学热力学的相关知识对学生认识化学反应中的能量变化、理解化学反应方向与限度起着至关重要的作用,但一直是高中化学学习中的难点。教材的编排方式直接影响到学生的学习难度和教师的有效教学。韩国高中化学教材化学热力学知识编排运用多种直观呈现方式,降低学习内容的抽象性;依据学生认知特点层层递进呈现知识,从而降低学习难度;运用实验教学、渗透STS教育等方式培养学生科学探究能力和知识运用能力。这些特点都值得我国高中化学教材借鉴。     

高中化学3套必修教材中化学概念的比较

对3种版本高中化学必修实验教材中化学概念的编排体系、呈现方式等方面进行了对比分析,并从教学的角度提出了几点思考意见。     

中英化学教材“化学反应速率”内容比较研究

“化学反应速率”综合体现了微粒观、实验观及科学本质观等化学基本观念,是提高学生科学素养的重要载体。从内容选取、内容编排与内容呈现3个方面对英国索尔特高级化学课程教材与国内化学教材中“化学反应速率”相关内容的编写进行比较,并简要阐述几点对化学教材编写和化学教学的启示。     

基于动态平衡观建构的教学研究——以“化学反应的限度”为例

以"化学反应的限度"为例,剖析了3套高中化学必修教材中关于该内容的编排特点,通过对学生"化学反应的限度"认识发展层级和认知障碍点的分析,以生活经验出发建构"化学反应的限度"和"化学平衡"的概念,采用"平衡-动态平衡-物理平衡-化学平衡"4个步骤建构"化学平衡是动态平衡"的概念,并在实证的基础上,帮助学生建构大多数化学反应有一定的限度的基本观念。     

中德初中化学教材中“原子”编写的比较

原子是初中化学课程的重要知识内容,是初中学生学习的重点和难点之一,不同的教材内容和编排对学生的学习有着不同的效果。本文从内容体系、编写思路、呈现方式3个方面对中国和德国的4种初中化学教材中“原子”的编写进行比较。     

英国CIE A-level化学教材与人教版高中化学教材中“有机化学”模块的比较研究

以中英2国高中化学教材中的有机化学模块为切入点，对英国CIE A-level化学教材与人教版高中《化学2（必修）》及《有机化学基础（选修5）》在该模块中的课程标准、结构体系、内容选取及组织呈现、栏目设计、典型知识点的编排等方面进行比较，分析英国CIE A-level化学教材的特色和优势。     

材料化学课程内容的设计

材料化学是一门新兴的交叉学科,其对应课程内容还没有得到一致的认同。从材料化学学科概念和课程知识点的认知出发,以材料的结构、材料的制备、材料的性能和材料的表征等4个方面作为材料化学的课程内容,以材料的制备为核心内容,阐述了4个方面具体内容的选择和设计,以期建立材料化学独立而普适的课程内容体系。     

红外光声光谱技术结合稳健回归用于油菜籽定量分析

将稳健偏最小二乘回归和偏稳健M回归应用于油菜籽红外光声光谱分析中含氮量、含油量与硫苷含量的测定。结果表明,利用红外光声光谱技术可以实现油菜籽品质的快速测定。同时,稳健回归模型较经典偏最小二乘回归模型可以更好地规避异常值影响,进而优化定量分析结果;其中,稳健偏M回归稍优于稳健偏最小二乘回归。     

Development of a High-Fibre Multigrain Bar Technology with the Addition of Curly Kale

The aim of this study was to find the effect of kale and dietary fibre (DF) on the physicochemical properties, nutritional value and sensory quality of multigrain bars. A recipe of multigrain bars was prepared with the addition of fresh kale (20% and 30%) and DF preparations (apple, blackcurrant, chokeberry and hibiscus). The bars were baked at 180 °C for 20 min. These snack bars, based on pumpkin seeds, sunflower seeds, flaxseed and wholegrain oatmeal, are a high-calorie product (302–367 kcal/100 g). However, the composition of the bars encourages consumption. In addition to the ability to quickly satisfy hunger, such bars are rich in many natural ingredients that are considered pro-health (high fibre content (9.1–11.6 g/100 g), protein (11.2–14.3 g/100 g), fat (17.0–21.1 g/100 g, including unsaturated fatty acids), carbohydrates (20.5–24.0 g/100 g), as well as vitamins, minerals and a large number of substances from the antioxidant group. The addition of kale caused a significant increase of water content, but reduction in the value of all texture parameters (TPA profiles) as well as calorific values. The content of polyphenols was strongly and positively correlated with the antioxidant activity (r = 0.92). In the bars with 30% addition of kale (422 mg GA/100 g d.m.), the content of polyphenols was significantly higher than based ones (334 mg GA/100 g d.m.). Bars with the addition of the DF were characterized by a higher antioxidant activity, and the content of carotenoids, chlorophyll A and B and polyphenols. High sensory quality was demonstrated for all (from 4.8 to 7.1 on a 10-point scale). The addition of fibre preparations was also related to technological aspects and allows to create attractive bars without additional chemicals.     

用燃烧炉及离子色谱仪测定原油中总氯、有机氯、无机氯含量的方法研究

使用燃烧炉及离子色谱仪测定原油中总氯含量,然后用常压蒸馏方法(ASTM D86)进行原油切割,得到204℃前馏分油,以燃烧炉及离子色谱仪测定其中有机氯含量,换算得到原油中有机氯含量,最后通过差减法计算得到原油中无机氯含量.     

Determination of OH groups in humic acids using methylation with dimethylsulfate

The methylation of humic acids (HA) with dimethylsulfate in acetone and methanol followed by the iodometric determination of the methoxy groups (Zeisel reaction) were applied to determine the contents of –OH groups in solid samples of HA of different origins. For the coal- and peat-derived HA samples, the contents of –OH groups determined after methylation in acetone ranged from 6.6 to 8.7 mmol/g, whereas the contents of –OH groups determined after methylation in methanol ranged from 4.0 to 5.0 mmol/g. These differences may be related to the content of carboxylic groups in the HA molecule that were not methylated in methanol, as confirmed by a comparison with results of conventional titrimetric determinations. Observed differences were interpreted as results of different polarity of both solvents and alkalinity of the reaction mixture during the methylation. The contents of alcoholic groups as well as some other minor –OH groups can be estimated using the –OH group contents obtained after methylation in both solvents together with the results of the conventional determinations of acidic functional groups. A repeatability of the –OH groups determination as estimated from a series of triplicate analyses of different HA samples (n = 7) was in range of 0.15–0.73 mmol/g and 0.08–1.06 mmol/g (standard deviations) for methylation in acetone and methanol, respectively. Thus, the average repeatability of the –OH groups determination was estimated to be 0.38 and 0.50 mmol/g for methylation in acetone and methanol, respectively.     

Antioxidant activities and bioactive compounds of five Jalopeno peppers (Capsicum annuum) cultivars

The present study was designed to evaluate the contents of different antioxidants compounds and their antioxidant activities in Jalopeno peppers (Capsicum annuum) cultivars (El Dorido, Grande, Tula, Sayula and El Rey) extracts. Free radical scavenging activity of Grande was recorded as high as 87% followed by El Dorido (83%). Results of reducing power (Fe³⁺ to Fe²⁺) showed that Grande (0.85%) and El Dorido (0.81%) fruit extract absorbance value were close to synthetic antioxidant BHT (0. 97%) obtained at100 μg/mL. The results showed that total phenolic content of El Dorido and Grande were significantly higher compared to other Jalapeno pepper. Results indicated strong and positive correlation between antioxidant activity and carotenoids content (r = 0.75), vitamin C (r = 0.78) and total capsaicinoids (r = 0.84), respectively. The results of the antioxidant activity assays showed that the El Dorido and Grande had strongest antioxidant activity compared to other peppers cultivars in this study.     

Total phenolic content,ferric reducing and DPPH scavenging activity of Arum dioscoridis

Arum dioscoridis, locally called ‘Gavur pancari’, is a wild plant the leaves of which have been used as vegetable and for preparing special soup which has a sour taste. This study was set up to determine in vitro antioxidant activities and total phenolic and flavonoid contents of different extracts of A. dioscoridis. Free radical scavenging activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing activity with different concentrations of ethanol, methanol, acetone and water extracts of the plant leaves. Total phenolic and flavonoid contents were widely variable depending on solvents. Ethanol and methanol extractions of the plant material showed better performances with respect to both phenolic and flavonoid contents, respectively. The highest phenolic and flavonoid contents of ethanol and methanol extracts were 100.890 mg/g GAE and 72.643 mg/g QE, respectively. The lower DPPH scavenging and ferric reducing activities were determined in comparison with previous reports and standard synthetic chemicals.     

空气中水含量的计算及其在色谱分析中的应用

本文介绍了空气中水含量的计算式并编制了空气中的水含量表。实验证明,表上的数据适用于色谱分析。     

核磁共振法测定西洛他唑含量

建立核磁共振（1H NMR）法测定西洛他唑含量的方法。采用BrukerAvanceⅢ400MHz核磁共振波谱仪,以1,2,4,5-四氯-3-硝基苯为内标,氘代氯仿为溶剂,zg30脉冲序列。对实验参数如扫描次数、延迟时间等进行优化。西洛他唑质量在5-30mg范围内,样品和内标物的积分面积比值与样品和内标物的质量比值呈现良好的线性关系,线性相关系数r=0．9953,测定结果的相对标准偏差小于0．4％（n=5）。该方法可用于药品的质量控制和监管。