如何教给同学系统的，巩固的化学基础知识

在中学化学教学大纲上指示,中学化学教学的基本任务:“第一就是使学生获得一定的系统的和巩固的化学基本知识……。”我觉得这样的要求是非常恰当的。系统的鞏固的化学基本知识,就不是零碎的、片面的、散乱的一堆化学材料,而是系统的、科学的、自然界物质变化的规律;不是无用的、累赘的、死板的知识,而是学了化学之後,能获得合乎高等学校要求的化学基础,或是直接为国家的生产建设服务。因而在正确的进行系统的、鞏固的基本化学知识的讲授     

聚合物不同相态X-射线衍射的数学描述

<正> 由于电子计算机的迅速发展和广泛应用,使得已被国内外普遍用来研究聚合物结构的“分峰法”(分解聚合物的X-射线衍射重叠峰的方法)成为一个切实可行的、有效的新方法。分峰法的前提和基础是要有反映聚合物各相态X-射线衍射峰峰形规律的合理的和确切的数学模型,这对聚合物结构的研究有着直接的重要的影响。七十年代迄今,国内外现有的关于聚合物不同相态的X-射线衍射的数学描述尚无通用的、统一的形式,     

化学成绩提高的方法

为社会主义建设的成就和伟大的共产主义思想所鼓舞的千千万万的教师大军,坚持不懈地获得巩固的、深刻的和自觉的知识,培养学生们的苏维埃爱国主义和苏维埃民族自豪感,无限忠诚於伟大的苏联共产党。出现了很多没有留级生的教师。作为一个比较年轻的化学教师的我,愿意提供一下我自己如何消灭留级生现象的意见,并且肯定地说,克服留级生现象的任务是完全可以解决的。     

姜黄素衍生物与类似物的构效关系研究进展

根据目前对姜黄素衍生物与类似物的结构与药理作用的关系的研究现状,论述了姜黄素衍生物与类似物的结构与其抗氧化、抗炎和抗肿瘤的药理作用的关系,包括对姜黄素及其衍生物与类似物的结构修饰与其活性之间的关系的论述。大量的实验结果显示姜黄素衍生物与类似物的药理作用与其结构中所具有的官能团有着密切的关系,这为新药开发提供了一个很好的方向。     

泽林斯基学派底发展道路(二)

二、烃的互相转变泽林斯基及其学派在烃的互相转变方面的研究,也有不可比拟的巨大成就。石油工业在国民经济中是相当庞大的、最重要的工业部门之一,天然气和石油是烃的最重要的来源。全世界石油年产量达三亿吨以上(不包括苏联在内),它的产量仅次于煤炭工业。但是几乎所有产品都用来做内燃机的燃料、润滑油等,仅有少数的作为化学工业的原料,然而利用石油作化学工业原料的需要是与日俱增的。对于石油的产品用为内燃机燃料及润滑油的要求,在今后会变得更为严格,这就是说:在不同用途的产品中烃类的化学组成不是完全没有关系的,仅一定类型的烃类在现代的航空、汽车及拖拉机发     

在化学教学中对学生的科学—无神论教育

在对学生的科学-无神论的教育中,化学教师的任务取决于我们苏维埃学校的总任务。苏维埃的学校是“教育出能够彻底建成共产主义一代”的工具。共产主义与宗教是不相容的。共产主义者“不能够也不应该对表现在宗教信仰形式中的无知、愚昧、和黑暗势力熟视无睹。”“因为党是拥护科学的,而宗教偏见是反对科学的”。在培养极积的、自觉的共产主义建议者的事业中,对学生的科学-无神论教育是化学教师的一项极其重要的任务。在共产党和苏联政府的领导下,总的来讲我们的学校卓有成效地担起了自己的教育-教养的任务。她培养了掌握科学基础的、思想健全的、体魄     

1997年全国高中学生化学竞赛(初赛)试题与试题分析

编者按今年的全国高中学生化学竞赛的初赛刚刚结束。我们认为这次竞赛的试题较好地体现了今年5月全国高中学生化学竞赛工作会议上再次肯定的试题的水平要求：原理水平大致与人民教育出版社的《化学读本》相当，基本上不涉及更高一级的，即大学化学的原理，但考虑到冬令营的优胜选手以及参加国际竞赛的选拔，需要补充一定量的静态立体化学的知识（包括立体异构），当然试题涉及的具体化学内容本身对中学生是陌生的，但用竞赛学生的已有知识以及适当增加的知识为基础是可以理解的。为进一步考察试题的难易，我们对试题作如下的分析。此试题有1…     

改进的微乳液聚合制备的聚甲基丙烯酸甲酯的力学和光学性能研究

研究了改进的微乳液聚合方法制备的聚甲基丙烯酸甲酯(PMMA)的力学和光学性能, 并与本体聚合制备的PMMA相比较. 研究结果表明, 由改进的微乳液聚合制备的PMMA具有较高的Tg和富间规度, 在较宽的温度范围内具有较高的力学模量. 此外, 它的拉伸强度、拉伸模量及断裂伸长率均比本体聚合制备的PMMA样品高. PMMA的折光率与制备方法关系不大, 但由改进的微乳液聚合制备的PMMA样品消光系数更小, 更加透明. 这说明由改进的微乳液聚合方法制备的PMMA具有更广泛的应用前景.     

Mn助剂对CuFeZrO2低碳醇合成催化剂的修饰作用

利用程序升温还原和原位漫反射红外光谱技术研究了Mn修饰的CuFeZrO2催化剂的结构特性,并测试了催化剂的CO加氢合成低碳醇的反应性能.研究表明，适量添加锰助剂有利于提高催化剂的反应活性,提高产物中C2＋醇的含量,抑制甲烷的生成,但随锰含量的增加催化剂的活性和选择性呈现先增加后下降的趋势.程序升温还原的测试表明,锰助剂通过与铜的相互作用使铜的还原变得困难,影响铜在催化剂上的状态,随锰的加入量的增加这种作用得到加强.铜分散度的测定表明锰促进了铜的分散,利用探针分子CO在催化剂上吸附的漫反射红外光谱研究发现,锰助剂可以提高组分间的相互作用,影响铜的电子性质,从而增加了CO在铜上的吸附.     

电化学制备异质二氧化钛结构增强其在光电分解水中转化效率（英文）

本文描述了一种利用电化学方法合成第二型异质二氧化钛纳米棒结构的方法,这种纳米棒由部分还原的黑色二氧化钛和原始的白色二氧化钛组成.这种异质结结构的半还原的二氧化钛纳米棒与原始的白色二氧化钛和完全还原的黑色二氧化钛纳米棒相比,展现出更好的光电催化性能.这可归结于这种条件下合成的纳米棒具备的协同作用.一方面,这类结构增强了整个太阳光光谱的利用率.底层的黑色二氧化钛能够大量吸收可见光,而上层的白色二氧化钛能够较好的利用太阳光中紫外光的部分.另一方面,因为形成了第二型异质结结构,电荷的激发分离和传输得到了有效的控制.这种简单的制备方法可进一步拓展合成其他金属氧化物,来进一步研究光电分解水的性能.本文利用传统的三电极系统:0.05 mol/L的硫酸作为电解液,在加–0.5 V的偏压下进行.相比与已报道的还原手段,该电解液中质子的浓度相对比较低,可以保证这个还原过程逐步发生.电化学还原曲线可以明显反映二氧化钛还原的过程,尽管从扫描电子显微镜中很难观察到响应的区别,但是在该过程中,电极片的颜色发生了明显的变化.相应的,我们将这个系列的电极进行了光学和晶体学的研究,发现其在还原过程中,能带能够逐步减小.而在X射线衍测试当中,仅最终完全还原的得到的样品在20度左右出现两个额外的峰,可归结为还原状态的二氧化钛.电化学扫描进一步测试其能带的相应位置,证明了黑色被还原的二氧化钛和白色的原始二氧化钛是同时存在的.最后将这个系列光电极光电催化分解水的性能进行了比较,发现在同等的测试条件下,形成异质结结构的二氧化钛具有最高的光催化效率,其值大约是白色二氧化钛的三倍,同时也比纯黑的二氧化钛增长了20%左右.另外,异质结结构的二氧化钛与黑色的相比,在可见光区域有相同的效率的同时具备更好的紫外光转化效率.最后,我们分析了异质结形成以后的相对应的能带结构,该结构能够更好的促进光吸收和转化.     

The depth distribution of organic additives in mortar measured with plasma-based Secondary Neutral Mass Spectrometry

Amino alcohols (AMA) have been found to be successful in corrosion prevention of steel-reinforced concrete [1]. However, to work effectively the amino alcohol has to be located at the interface between the concrete and the steel rods reinforcing the stability of the building material [2]. Corrosion prevention for new buildings is easy because the corrosion inhibitor has already been added to the liquid concrete mixture and thus can easily reach the steel rods. With subsequent corrosion prevention measures for existing buildings, however, the problem of transport of the corrosion inhibitor through the solid concrete to the steel surface has to be solved first. In order to determine penetration, transport behavior, and transport rate, an AMA was applied to one face of rectangular mortar blocks used as model samples. A certain period of time for dwelling was given to allow the AMA to penetrate into the mortar. Moreover, the influence of the ambient humidity during the application was investigated. The analysis of the mortar was made by Secondary Neutral Mass Spectrometry, a technique used for the first time for this type of material because of the easy sample preparation, short analysis time, and high sensitivity.     

模拟混凝土孔隙液中D-葡萄糖酸钠复合缓蚀剂对钢筋的阻锈作用

应用电化学技术, 结合扫描电子显微镜(SEM)观测, 研究D-葡萄糖酸钠、钼酸钠和硫脲三组分复合缓蚀剂对模拟混凝土孔隙液中钢筋腐蚀行为的影响及其阻锈作用. 结果表明: 在含3.5% (w) NaCl的模拟混凝土孔隙液中, 复合缓蚀剂具有协同效应, 对钢筋有良好的阻锈作用. 当D-葡萄糖酸钠、钼酸钠和硫脲浓度分别为750、250和500 mg·L^-1时, 对钢筋的缓蚀效率可达到94.5%. 应用软硬酸碱(HSAB)理论分析缓蚀机理, 可认为三组分复合缓蚀剂在钢筋表面共同形成保护膜而阻止钢筋的腐蚀.     

Electrochemical and Surface Analysis Studies on the Carbon Dioxide Corrosion of X‐65 Carbon Steel

A comprehensive study of the CO₂ corrosion of carbon steel (X‐65) at low partial pressures of CO₂ is reported in this paper. Field emission scanning electron microscopy (FESEM), Raman spectroscopy (RS), synchrotron radiation‐grazing incidence X‐ray diffraction (SR‐GIXRD), and electrode kinetic studies have confirmed that chukanovite, magnetite and siderite are the main corrosion products at low partial pressures of CO₂. Chukanovite forms predominantly in the presence of CO₂, while magnetite was found to be the major corrosion product in the absence of CO₂, although the majority of previous work based on conventional ex‐situ materials characterization techniques has implied that siderite is the main corrosion product. Here, it is shown that the nature of corrosion products is strongly dependent on the experimental conditions at low pressures of CO₂, which has not been elucidated in previous studies. Accordingly, this study has made a significant contribution to identifying the true nature of corrosion scales formed at low partial pressures of CO₂ allowing the development of effective anti‐corrosive agents for the control and prevention of carbon steel corrosion at low CO₂ partial pressures.     

Scientific fraud in corrosion science research: A review

This article examines the issue of scientific misconduct and its implications on corrosion science research through a decade (2001–2011). An analysis is presented of an increasing body of cases in which allegations have been made and violations of legal and ethical research standards have been substantiated. The frequencies with which scientists fabricate and falsify data, or commit other forms of scientific misconduct, are discussed. In this review, the image of scientists as objective seekers of truth is periodically jeopardized by the discovery of a major scientific fraud. This review shows how easy it can be for a scientist to publish fabricated data in the most prestigious journals, and how this can cause a waste of financial and human resources. Case examples illustrated and investigated in this review are related to corrosion science research. Recommendations toward the prevention and resolution of potential or actual instances of scientific misconduct in corrosion science research are proposed.     

Sol–Gel-Derived Corrosion-Protection Coatings

There is a current need for alternative coatings that can provide corrosion resistance to metals or alloy surfaces due to the environmental hazards posed by conventional coatings. Herein, we report on novel organically-modified sol–gel coatings for the protection of metal and alloy surfaces. The basic concept of chemical conversion of metal surfaces is based on deposition of a hydrophobic, nonporous sol–gel barrier layer for surface protection and corrosion prevention. The properties of these organosilica coatings can be tuned by varying the composition of precursors. The evaluation of hydrophobicity, adhesive strength, and anticorrosion properties of organically-modified sol–gel derived coatings suggests their potential utility as technologically-compatible alternatives to conventional coatings.     

Corrosion protection of carbon steel in acidic media by expired bupropion drug; experimental and theoretical study

The effects of expired bupropion on the corrosion protection of carbon steel in hydrochloric acid (1.0 M) and sulfuric acid (0.5 M) solutions were examined by Fourier transform infrared (FTIR) spectroscopy, Tafel polarization and electrochemical impedance spectroscopy (EIS). Bupropion concentrations in both acid solutions were raised, which improved corrosion prevention. Bupropion was a mixed inhibitor because it retarded the anodic and cathodic processes, as indicated by polarization data. The inhibition efficiency decreased with the increasing temperature from 25 to 55 °C. In the presence of bupropion, the activation energies of corrosion in both acid solutions increased. The thermodynamic quantities were deduced from the influence of temperature on the corrosion process of carbon steel in both acid media. Bupropion adsorption on carbon steel followed the Langmuir adsorption isotherm. The polarization data yielded outcomes consistent with the results arising from impedance measurements. FTIR spectroscopy showed the active sites of bupropion molecule during adsorption on the alloy surface. The theoretical study and molecular dynamics simulation of bupropion was done by a density functional theory (DFT) approach to realize the effects of molecular structure on the inhibitive action of bupropion.     

Methylchlorophosphanes and Their Reaction Products

Methyldichlorophosphane and dimethylchlorophosphane can be prepared only with considerable difficulty. The ease with which they yield numerous reaction products is an indication of the pronounced reactivity of these organohalophosphanes. Possible applications of such organophosphorus compounds exist inter alia in the fields of plant protection, corrosion prevention, and flame retardants, as well as in the catalysis of gas phase reactions, for instance the desulfurization of gas mixtures.     

Band edge modulated conjugated polymers for oxidation prevention

The impact of electron transfer (ET) from a series of band edge modulated polymers to atmospheric oxygen is examined in connection with substrate oxidation prevention. Polymers with the highest occupied molecular orbital (HOMO) energy level below and above the oxygen energy level were tested and the former showed better efficiency. Furthermore, the oxidation prevention efficiency of a polymer with lower HOMO increased by two orders of magnitude, when the pores on the film were filled with spherical molecules, [6,6]-phenyl-C61-butyric acid methyl ester. We found that the polymer surface hydrophobicity has little or no influence on oxidation prevention. It is interesting to note that a polymer with a hole mobility of 8 × 10(-10) cm(2) V(-1) s(-1) showed a two-fold increase in oxidation prevention efficiency compared to a polymer with a hole mobility of 6 × 10(-5) cm(2) V(-1) s(-1). Over all, from the concerted approach, we conclude that a polymer devoid of pores with the HOMO energy level below oxygen and low charge carrier mobility is a suitable candidate for prevention of substrate oxidation/corrosion.     

Experimental and theoretical studies of carbon steel corrosion protection in phosphoric acid solution by expired lansoprazole and rabeprazole drugs

The effects of expired lansoprazole and rabeprazole on the corrosion protection of carbon steel in phosphoric acid (3.0 ?M) solution were examined by Tafel polarization and electrochemical impedance spectroscopy (EIS). Lansoprazole and rabeprazole concentrations (0.5, 1.0, 5.0 and 10 ?mM) in acid solution were raised, which improved corrosion prevention. Both lansoprazole and rabeprazole as the mixed inhibitors retarded the anodic and cathodic processes, as indicated by polarization data. With the increasing temperature in the range of 25–55 ?°C, the inhibition efficiency drops from 92.9% to 69.3% for lansoprazole and from 94.8% to 74.2% for rabeprazole. The major decrease in the inhibition efficiency with ascending temperature proved the physisorption of the drugs. The activation energies for carbon steel corrosion in H₃PO₄solution were enhanced from 41.6 ?kJ ?mol^?1 to 81.9 ?kJ.mol^?1and 85.9 ?kJ ?mol^?1 for lansoprazole and rabeprazole, respectively. The influence of temperature on the corrosion process of carbon steel in the acid medium was used to derive the thermodynamic quantities of corrosion. The adsorption of both lansoprazole and rabeprazole on carbon steel followed the Langmuir adsorption isotherm. The polarization data yielded outcomes that were consistent with the results arising from impedance measurements. The theoretical study of both lansoprazole and rabeprazole was done by a density functional theory (DFT) approach to realize the effects of molecular structure on their inhibitive action. Both lansoprazole and rabeprazole contain a higher E_HOMO, a lower E_LUMO and a lower energy gap than some inhibitors earlier reported as good corrosion inhibitors in the literature.