共查询到20条相似文献，搜索用时 109 毫秒
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分解反应、歧化反应、中和反应、还原反应、氧化反应是无机化学中重要的反应,本文分析了发生这些反应的无机物,并列举了它们发生反应及反应条件的英文句型表达方式,希望对化学专业英语教学提供一些参考和借鉴作用。 相似文献
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计算了以水为溶剂,过氧化氢氧化苯酚羟基化合成苯二酚的反应体系的反应焓变、吉布斯自由能变和反应的平衡常数。结果表明,生成邻苯二酚、对苯二酚的反应均为放热反应;反应在298K-368K范围内是热力学上可自发进行的反应;反应的平衡常数很大,理论上反应的平衡转化率很大。 相似文献
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显色反应是将试样中被测组分转变成有色化合物的一类化学反应,有配位显色反应和氧化还原显色反应之分。而在我们经常接触的化学反应中就有许多显色反应,比如酸碱指示剂的显色反应、淀粉与碘水的显色反应、亚甲蓝的反复变色反应以及化学震荡反应等。 相似文献
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用碱厂废渣添加工业磷酸、氨水进行反应来制缓释性肥料-六水磷酸铵镁,对该反应的搅拌速度、反应时间、反应温度、酸解时间、物料配比和反应pH值进行了实验研究。结果表明,搅拌速度、反应时问对反应的影响不大;反应温度取室温;酸解时间、物料配比、反应pH值对反应的影响较大;对反应影响最大的因素是物料配比;最优物料配比是H3PO4：氨二泥：氨水=1：2．1：2．1（质量比）。 相似文献
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陈大权 《青苹果(高中版)》2012,(2):21-25
有机化学反应种类多样、产物复杂,有的反应进行缓慢,有的反应进行迅速,还存在着多种竞争反应和三大选择性——化学选择性、区域选择性和立体选择性。化学选择性也可以看做竞争反应,比如醇在浓硫酸作催化剂的条件下加热存在消去反应和取代反应的竞争反应,一般来说高温成烯、低温成醚,同样,卤代烃的水解也存在类似的竞争反应。 相似文献
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一、教学案情在《氧化还原反应》一节的教学中,笔者按照传统的教学模式进行了教学。即通过复习初中的＂氧化反应＂和＂还原反应＂为例,从得氧、失氧角度分析氧化还原反应,并指出氧化剂、还原剂,然后让学生发现这些反应中元素化合价的改变,指出氧化还原反应的特征,并指出氧化反应和还原反应是同时进行的。再通过元素化合价变化,导出氧化还原反应的本质是电子的转移,继而从氧化还原反应的本质确定氧化剂和还原剂。在讲解 相似文献
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在化学变化中,常常伴随一些现象的发生,如：放热、发光、变色、放出气体、生成沉淀等等。但是二氧化碳气体与氢氧化钠溶液反应却没有明显现象,本文分别从反应前后装置内压强的变化、反应后气体是否存在、反应后生成物的性质等角度,使“无”现象的反应转化成“有”现象的反应。 相似文献
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按照酸碱质子理论，不但酸碱中和反应，酸碱自离反应为酸碱反应，而且盐类的水解反应，某些过氧化物的水解反应，弱酸与强酸性溶剂的作用，某些物质与溶剂的加合作用，某些高价阳离子与水的配位作用，以及强酸强碱盐的溶解作用均属于酸碱反应，且反应产物为原酸的共轭碱和原碱的共轭酸． 相似文献
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从热力学角度分析了固相反应的吉布斯自由能变,印证了固相反应一旦发生,便能进行到底的结论.并且,探讨了固相反应在化学合成和保护环境等方面较液相反应具有非常明显的优势. 相似文献
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Parental reactions to children's negative emotions: longitudinal relations to quality of children's social functioning 总被引：7，自引：0，他引：7
Relations between self-reported parental reactions to children's negative emotions (PNRs) and children's socially appropriate/problem behavior and negative emotionality were examined longitudinally. Evidence was consistent with the conclusion that relations between children's externalizing (but not internalizing) emotion and parental punitive reactions to children's negative emotions are bidirectional. Reports of PNRs generally were correlated with low quality of social functioning. In structural models, mother-reported problem behavior at ages 10-12 was at least marginally predicted from mother-reported problem behavior, children's regulation, and parental punitive or distress reactions. Moreover, parental distress and punitive reactions at ages 6-8 predicted reports of children's regulation at ages 8-10, and regulation predicted parental punitive reactions at ages 10-12. Father reports of problem behavior at ages 10-12 were predicted by earlier problem behavior and parental distress or punitive reactions; some of the relations between regulation and parental reactions were similar to those in the models for mother-reported problem behavior. Parental perceptions of their reactions were substantially correlated over 6 years. Some nonsupportive reactions declined in the early to mid-school years, but all increased into late childhood/early adolescence. 相似文献
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论述了水相Diel-Alder反应的研究新进展，重点举例说明了水作为Diel-Alder反应介质的独特性－加快反应速度，强化反应的立体选择性；其反应加速的微观反应机理主要是疏水效应和氢键作用。 相似文献
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在微流注放电条件下,通过选取秸秆组分的模型化合物,研究了其在等离子体条件下的水解反应,利用键能百分比规则估算了设计的单分子反应、双分子反应和自由基反应等步骤的活化能,由此初步确定了秸秆等离子体水解反应过程。 相似文献
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Robert Grassinger Annette Scheunpflug Horst Zeinz Markus Dresel 《High Ability Studies》2018,29(1):37-49
Learning form errors seems to be crucial for talent development, but there is evidence that students learn little from their errors during school instruction. This work addressed the interplay of different adaptive reactions to errors (affective-motivational adaptive and action-related adaptive reactions), a positive error climate in the learning context and cognitive abilities with regard to their effect on academic achievement. A longitudinal data set with 2092 students attending 74 classes was analyzed with a two-level path modeling approach (students in classrooms). The results confirmed the assumption that affective-motivational adaptive reactions to errors encourage action-related adaptive reactions to errors which, in turn, foster academic achievement. Furthermore, analyzes indicated that the relationship between a positive error climate in the classroom and academic achievements is mediated by students’ individual reactions to errors. In contrast to expectations, students with higher cognitive abilities did not show more adaptive reactions to errors. 相似文献
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In this study, we investigated how students organized their knowledge about organic chemistry reactions in a transformed curriculum, including their choices, abilities, and changes over time. This transformed curriculum focuses on interpreting the underlying mechanistic patterns of chemical reactions and emphasizes the principles of reactivity in organic chemistry. Data from this study were collected at beginning and end of an Organic Chemistry II course using an open and closed online categorization task with a set of organic chemistry reactions. In the open task, participants organized the set of reactions as they chose, giving us insight into how the participants preferred to organize their knowledge. In the closed task, participants were asked to organize the set of reactions in a specific way—by each reaction's governing mechanism—which would provide a measure of the students' ability to categorize the reactions in that way. We investigated the similarities and differences of the open and closed categorizations at each time of administration and analyzed the changes over time. Findings from this study emphasized the efficacy of the transformed curriculum for: (a) promoting a focus on process-oriented features of reactions over static features of a reaction and (b) increasing the students' abilities to categorize a set of reactions according to the mechanism governing the reaction. Findings revealed implications for the transformed curriculum, which addresses key areas for improvements, potential implications for research, and also limitations of the current study. We further describe possible extensions of this study to how the open and closed categorization tasks may be used for research and instruction in other science, technology, engineering, and math disciplines. 相似文献
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《Journal of moral education》2012,41(2):89-93
Abstract The present study investigated the degree to which transgressors’ affective reactions influence children's moral judgments. Eighteen children at each of three different grade levels (first‐, second‐, and third‐grade) were required to make judgments of the goodness or badness of four different transgressors.The transgressors acted out of good or bad intent, produced low or high levels of damage and displayed the affective reactions of happiness, sadness or neutrality because of the outcomes they produced. Results showed that the transgressors’ affective reactions significantly influenced the children's moral judgments. More importantly, the children excluded intention information when they evaluated transgressors who displayed reactions of happiness. But, they did not exclude intentions when they evaluated transgressors who displayed reactions of sadness or neutrality. A number of hypotheses were offered to account for the means by which reactions of happiness block children's use of intent information. 相似文献
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配合物之间的氧化还原反应是电子从一个配合物分子的中心原子(或离子)转移到另一个配合物分子的中心原子(或离子)上去的电子转移反应。本文介绍此类反应的两种反应机理,即外界反应机理和内界反应机理。 相似文献
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Gnanamani Simiyon G. 《Resonance》2018,23(6):683-691
‘Double displacement reactions’ are commonly observed in solutions and aqueous phase. They are less common in solid phase and generally requires high temperature to take place. However, in this article, we report double displacement reactions taking place in solid phase at room temperature. We also highlight the criteria required for the occurrence of displacement reactions in solid state at room temperature. The driving force for all the double displacement reactions is explained using Pearson’s hard and soft acid and base (HSAB) concept, and in few cases involvement or aid of water of hydration is observed. 相似文献