乙烯、乙炔加成反应实验的改进

本实验利用碘蒸气替代溴的四氯化碳溶液,改进了乙烯、乙炔的加成反应.     

乙烯实验室简易制法的探究

传统实验室制取乙烯方案都不同程度的存在着装置复杂、副产物多、耗时时间长等缺点,笔者经过长时间的探索,尝试以乙烯利和氢氧化钠为试剂制取乙烯,实验获得了成功,该方法简单易行,易于操作,能迅速产生气体,适合学生用来探究乙烯的性质.本文从实验试剂、装置、数据等方面详尽地阐述了实验室制取乙烯的简易方法.     

用简易启普发生器制备乙炔的实验研究

1问题的提出 教师在讲课中演示乙炔的实验室制法和性质时,总是一次做完所有的性质实验,同时剩余气体也因反应无法终止而长时间点燃白白浪费,即使用饱和食盐水代替水,反应速度仍然很快,无法随时终止和控制反应,故提出对此实验的研究,力图达到用简易启普发生器制备乙炔.根据需要可以随时使反应终止和继续.     

乙炔与溴水加成反应的研究

用气相色谱法对乙炔与溴水加成反应的产物进行了分析，结果发现，除了生成1，2-二溴乙烯和1，1，2，2-四溴乙烷外，还生成了不少二溴乙醛Br2CHCHO。并对高中化学教材中有关内容提出了修改建议。     

浅谈乙烯和乙炔的化学反应活性

乙烯和乙炔的化学性质到底哪个比较活泼?本从乙烯、乙快的分子结构出发，结合具体反应条件，作出如下的初步探讨。     

实验室制备乙炔的实验探究

[问题]某课外实验探究小组的同学在学习乙炔的性质中,看到老师在演示乙炔的性质时所用乙炔气体的制备方法装置中(见下图)存在以下诸多缺陷:(1)反应速度太快,生成的乙炔气流不平稳。(2)反应一旦开始就无法停止,余下的乙炔     

乙炔的实验改进

利用教材上的方法来制乙炔，学生实验过程中反映出来的问题主要是：产生的气流速度太快，往往还没来得及做后续实验，气体就已经没有了，而且由于反应过于激烈，气流带出大量的泡沫浸湿棉花以后，气体流出受到阻碍，往往使学生有点手忙脚乱，而且此种气体如果用药品较多，产生的气体太多，污染也较严重，整个实验室内的难闻气味使师生的健康受到严重危害，为了克服此缺点，也为了使反应速率更易控制，对该实验作如下改进。     

实验室制取乙炔实验方法的改进

对实验室制取乙炔的实验方法进行了合理的改进，更有利于促进学生创造性思维的发展。     

使用蔗糖溶液制取乙炔

乙炔(Ｃ2Ｈ2)的实验室制法是运用电石(碳化钙)与水反应制得的。该反应的反应速度很快,难以控制。我们经过数次的实验,发现用蔗糖的水溶液代替食盐水制取乙炔,并依次完成乙炔与酸性ＫＭｎＯ4溶液和溴水的作用及乙炔的燃烧实验,获得了较为满意的效果。1　实验用品①6ｍＬＫＭｎＯ4溶液,0.1‰,ｐＨ=2。②水和多种不同浓度的蔗糖溶液各10ｍＬ　　③秒表、直尺、托盘天平、镊子、温度计④简易火苗高度测量装置(由直尺和一个可以感知高温的电路组成),如右图所示:　　2　所测数据表1　蔗糖溶液与电石反应(取平均值,电石质量为2克,溶液为10ｍＬ,测定…     

简化或避免分类讨论的若干策略

分类讨论用于解数学题有时会很繁复,为克服这一缺点,可用消去参数、整体换元、数形结合、变换主元、补集分析等方法简化或避免分类讨论.     

Non-anthropocentric Reasoning in Children: Its incidence when they are confronted with ecological dilemmas

This study used an individual structured interview to (1) verify the incidence of non-anthropocentric reasoning in 123 children attending the 3rd and 4th years in three primary schools in the Lisbon area (Portugal), when they are confronted with ecological dilemmas and (2) establish those places they frequented which permit animal contact. The results show a greater incidence of non-anthropocentric reasoning than that obtained in other international studies. This may be related to the focus of the questions asked, which invited children to imagine themselves as another animal or to present situations where human interaction is unfair. This incidence was found independently of gender, school origin and whether or not pets were owned, even with the more biologically complex animals. School year was the only variable proven to make a difference in conceptually more demanding questions. We also verified that the children's general past experience of nature is essentially aligned to ‘controlled environments depending on ongoing human management’, confirming a decline in direct contact with ‘natural and semi-natural environments’. However, this type of experience does not seem to exert a negative influence on their non-anthropocentric reasoning.     

生态系统中的特例

1生态系统成分中的特例 1．1植物中的消费者——菟丝子生产者都是自养生物，是生态系统存在的前提，是生态系统的基石，也是生态系统的主要成分，主要指绿色植物。但并不是所有的植物都属于生产者，如寄生在大豆植株上的植物——菟丝子，它不含叶绿体，叶片退化成鳞片，不能制造有机养料，而由黄色的丝状茎生出许多不定根，伸入到大豆茎内的组织里。     

Trait Understanding or Evaluative Reasoning? An Analysis of Children''s Behavioral Predictions

This study tested the hypothesis that in predicting the future behavior of an actor, older children rely on trait inferences, whereas younger children rely on global, evaluative inferences. Vignettes depicting actors engaging in trait-relevant behaviors were presented to 5- and 6-year-olds (N = 67) and 9- and 10-year-olds (N = 71). For each actor, children made predictions of future behavior, evaluated the goodness and badness of the actor, and rated each actor on a relevant trait. A mediational analysis found that the behavioral predictions of older children were mediated solely by trait ratings, whereas those of younger children were mediated by evaluative ratings. Furthermore, unlike older children, younger children made trait-like predictions only when they made an evaluation of the actor. These results suggest that young children utilize evaluative reasoning when making behavioral predictions, and therefore rely on an inferential process that is distinct from that of older children.     

论法律推理

法律推量是法律思维的重要形式，在法律逻辑中占有十分重要的地位，是司法工作乾必须具备的思维工具和智力手段，本分析了推理的含义，种类及进行正确的法律推理所应具备的条件，对如何把握法律推量作为初步探讨。     

立功成立起点是“到案时”还是“犯罪后”

《关于处理自首和立功具体应用法律若干问题的解释》规定立功的时间为犯罪分子到案后,对于此时间节点学界有着诸多诟病,有人提出了到案前立功论、犯罪后立功论等学说,但这些学说仍有无法解决的问题。立功的成立并非只有时间一个条件,而是有诸多要素共同决定,这些要素之间也会相互影响和变化,所以立功是否成立的判断需要全面考察构成要素。另外,立功的构成要素中不包含被告人人身危险性的减小。     

The Mean or Average Deviation is a Minimum when taken from the Median

The structure of students’ responses on a semantic differential instrument to certain facets of their university was analyzed by Tucker’s three-mode factor analytic procedure. Factors were identified and named for the R, P, Q and core matrices. Tucker’s procedure offers the investigator additional information in interpreting such response data. The additional information obtained from Tucker’s procedure over classical two-mode procedures, particularly the core box of interdependencies, was helpful in interpreting the semantic differential data.