“高”“新”“特”“妙”──’97高考化学第36题的评析

每年的高考化学试卷的“庐山真面目”一揭开,最后一道计算题总能给人以惊喜和启迪,并对今后一段时期的复习迎考产生良好的导向作用,'97高考化学第36题可谓“压轴题”中的“精品之作”。     

再谈“初三化学‘绪言’教学法的研究”

我们是师范学院化学系二年级的学生,本学期化学教学法的学习已进入到具体分析中学化学课的教学研究阶段,而初三化学“绪言”的教学就是具体分析研究的第一课。关于这一课,在老师的指导下,我们进行了课堂讨论和试教,在这两个过程中,我们对“化学通报”1956年10月号胡国华写的“初中化学绪言教学法的研究”进行了研究,对该文的某些偏点有不同的看法,试教后也有—些体会,现在提出来与同志们研究。胡老师一开始就认为“这一课上的好坏就直接关     

One hundred and forty years “Fresenius’ Journal of Analytical Chemistry”

The distribution of rare earth elements (REE) in a pooled soil sample collected from Zhangzhou, Fujian Province, China, was screened by a five-step sequential extraction procedure coupled with ICP–MS determination after preconcentration of REE and removal of the matrix by extraction with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP). The results showed that the distribution of REE in the different fractions of the pooled soil sample studied followed the order soluble species (46.76%) > species bound to organic matter (22.08%) > species in the residue (16.77%) > species bound to Fe–Mn oxides (2.02%). An effective method for speciation of REE, which utilized weak cation-exchange HPLC separation hyphenated with post-column derivatization and visible or on line ICP–MS detection, was, moreover, developed and successfully applied to the speciation of REE in the soluble extract of the pooled soil sample. The stability of known complexes of lanthanum during the HPLC separation was investigated with fluoride, citrate, and ethylenediamine tetraacetic acid (EDTA) chosen as ligands modeling those in the soil. REE in the soluble extract of the pooled soil sample were subsequently classified into three types of species –≤ + 1 charged complexes (negatively charged, neutral, and +1 charged), + 2 charged complexes, and “free” REE species. This method is expected to be useful for identification of bioavailable (or toxic) species of REE in environmental samples.     

Comment on “On the ‘simple check’ of electrocapillarity” by AY Gokhshtein

It is shown that the so-called “equation of solid-state electrocapillarity” derived by Gokhshtein from the simplest thermodynamic model, earlier used by Lippmann, is an incorrect modification that is returned to the classic Lippmann equation if to take into account the usual definition of differential capacity of the electrical double layer. Consequently, Gokhshtein’s experiments can actually confirm only the validity of the Lippmann equation (with deviations caused by physicochemical processes in the double layer, which could not be taken into account in the thermodynamic equations). The thermodynamic model is insufficient for the interpretations of these experimental results, whose understanding requires physical models of the different phenomena occurring at the electrode surface.     

Synthesis of Some Novel Phenyl Substituted Oxothiazolidin- 1’’,3’’,4’’-thiadiazolo-[3’,4’-b]thiazoline of 3β-Substituted Cholestane

Three title compounds 4a—4c have been synthesized by the cyclodehydration of 1’-benzylidine-4’-(3β-substituted-5α-cholestane-6-yl)thiosemicarbazones 2a—2c with thioglycolic acid followed by the treatment with cold conc. H2SO4 in dioxane. The compounds 2a—2c were prepared by condensation of 3β-substituted-5α-cholestan- 6-one-thiosemicarbazones 1a—1c with benzaldehyde. These thiosemicarbazones 1a—1c were obtained by the reaction of corresponding 3β-substituted-5α-cholestan-6-ones with thiosemicarbazide in the presence of few drops of conc. HCl in methanol. The structures of the products have been established on the basis of their elemental, analytical and spectral data.     

对“我是如何帮助同学树立牢固的‘克分子’、‘克原子’的概念的”一文的商榷

讀了化學通报1960年第4期中学化学教学栏內“我是如何帮助同学树立牢固的‘克分子’、‘克原子’的概念的”一文后,我觉得文中所介紹的經驗,用通过討論的形式来巩固学生所学的知識及澄清某些糊涂概念,以及为了把基本概念交代清楚,使学生易于理解和掌握,教师不应該只是照本宜讀,而应該另編一些通俗易懂的讲义,举些学生生活中所熟悉的例子作比喻,来说明基本概念的作法,都是值得我学习的。伹我觉得这样做时必須注意:(1)要严格遵守科学性的原則;     

对“征服‘不可驯服元素’的启示”一文的意见和更正

《化学通报》编辑部:我们都是重视和喜爱《化学通报》的读者。最近我们读了《化学通报》1982年第6期上“征服‘不可驯服元素’的启示”一文(以下简称“启示”),发现文中有不少错误和欠妥之处,现列举如下:(1)杰出的化学家 Lavoisier,就法文读音来说,是三个音节,中文早已统一译成“拉瓦锡”了。我国读     

Igor’ Vladimirovich Rybal’chenko turns sixty

Chronicle

Igor’ Vladimirovich Rybal’chenko turns sixty     

“测定”与“检定”

本刊一九八二年第六期45页的标题“纸色谱法分离测定金属离子”中“测定（determination）”一词欠妥。在分析化学中“测定”只用于定量,不能用于定性的工作。按该文内容是定性的——金属离子的检定。计算比移值也不能算定量分析工作,而是为了定性之目的。     

“友”和“敌”

人体必需元素是人体健康之“友” ,不能缺乏 ,更不能没有 ,否则就使人患病 ;另一方面 ,也不能过多(从理论上来讲 ,任何必需元素都不能过多 ,但现实生活中 ,有一些元素并不存在由于过多而致病的问题 ) ,否则会化“友”为“敌” ,使人中毒 ,这类例子是很多的。例如食盐 ,井岗山时期 ,国民党反动派对红军实行封锁 ,把食盐也列为封资物资。电影《闪闪的红星》中潘冬子给红军送盐时 ,为了逃避敌人检查 ,把盐用水溶解浸湿棉衣 ,到达后再把棉衣中的盐水挤出来熬盐 ,可见食盐对于人体是多么必要。可是 ,过多吃食盐会导致高血压已是公认的事实 ,并为…     

“有界”和“无界”

用马克思主义占领自然科学阵地,是科技战线实行无产阶级专政的一个重要方面。引导学生学习自然辩证法,以逐步形成辩证唯物主义的世界观和方法论,培养学生用马列主义、毛泽东思想分析问题和解决问题的能力,是化学教学的一项重要任务。这里刊登的两篇学习自然辩证法心得体会的短文,是四川省会东中学高七四级化学试卷的一部分。这样的答卷是旧中学所不能比拟的。因此,也是对教育界、科技界右倾翻案风一个有力的回击。     

Igor’ Vladimirovich Pletnev’s 50th birthday

Chronicle

Igor’ Vladimirovich Pletnev’s 50th birthday