培养学生绘制化学实验仪器装置图的做法

化学实验仪器和装置图表示仪器的形象、装配、组合形式和实验的某些操作方法等。在学生作化学笔记,完成实验报告,根据实验习题的要求设计仪器装置时,都要画出实验装置图。通过绘图,有助于学生加深对化学基础知识的理解;掌握仪器装置的原理及其使用方法;同时,还有助于培养学生的实验操作能力.现在谈谈培养学生绘制实验仪器装置图的一些做法。     

利用化学实验图库绘制实验装置图

介绍了用Windows画图板绘制常见化学实验仪器图的技巧,建立化学实验装置图库的做法和要求,以及利用图库中的化学仪器组合图片绘制化学实验装置图的方法.     

化学实验仪器和装置图的画法

绘制化学实验仪器装置图是中师化学实验教学的一个重要内容,是中师生应该具备的基本技能之一。在中师教学中,板书和仪器装置图的绘制往往不被重视。笔者就如何绘制化学实验装置图这一问题谈点粗浅的看法。     

绘制化学实验仪器与装置图应注意的几个问题

目前部分化学教育教学论文与教科书中存在绘制化学仪器与实验装置图图形残缺、失真、违反科学原理与构图原理的现象。化学教师要绘制符合要求的实验仪器和装置图,应从仪器的外观特征与内部结构入手,融入立体几何知识、美术构图原理与构图技法。     

简易灭火器的实验设计

人教版义务教育课程标准实验教科书九年级《化学》上册中,第七单元课题1“燃烧和灭火”中,第126页[活动与探究]试根据灭火的原理和上述实验,设计一个简易的灭火器（图1装置可供参考）。     

巧用Flash MX2004绘制化学实验装置图

结合实例介绍了用Flash MX 2004软件绘制常见化学实验仪器图的一般方法和技巧,以及利用已绘好了的单个化学仪器图组合为一套完整的实验装置流程图的步骤和方法。     

化学实验装置设计的课堂呈现方式研究

设计、评价或改进实验装置方案教学是全面检测学生化学科学素养的重要手段之一。目前化学实验装置设计的课堂教学中,学生设计装置的思维产品受限于实验器材难以大面积进入课堂,多止步于黑板板书或纸平面。尝试比较、使用了仪器操作法、学案分步法、演示文稿法、仿真实验软件和纸卡仪器法等不同课堂呈现方式实现化学实验装置设计,取得了较好的教学效果。     

实验化学的名师巨匠——本生

本生是一代实验化学的名师巨匠,他的一生在化学发展史上留下了光辉的一页。在几十年的科学实验和研究中,他潜心钻研化学理论,不断提高自己的实验技能。他亲自设计和改进了诸多实验仪器和装置,并为此做出了发明和创造。他的主要贡献有:创立了光谱分析法,发现了铯和铷两种元素,发明了本生灯和本生电池,并在化学工业的掘起和发展中做出了重要的贡献。     

高考化学实验试题的创意与设计

本文通过分析近几年高考化学实验试题命题的选材及创意的特点,提出了高考化学实验试题装置、操作创新设计的基本要求,并以启普发生器反应器的设计、防止液体倒吸发生装置的设计、测量气体体积装置的设计、喷泉实验装置的设计、具有特殊作用的实验改进装置的设计、Fe(OH) 2 的制备操作装置的设计为例剖析了高考实验命题与解题的思路。     

基于反射积分球和光纤传感无损快速检测盐酸小檗碱片含量

利用积分球和光纤传感技术,在相同条件下扫射不同化学原料药的反射光谱图,建立快速定性定量检测化学原料药的分析方法。以盐酸小檗碱为代表药考察单因素:压力、药片面积大小、药片摆放位置等因素对反射光谱图的影响,并考察其在添加一种和两种辅料的化学原料药的百分含量不同时,对反射光谱图的影响。结果表明:化学结构不同的化学原料药反射光谱图不同;在压力、药片面积大小、药片摆放位置不同时对反射光谱图的影响各不相同;化学原料药的百分含量不同,反射光谱图也不相同,在某一波长处其线性关系较好。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

关于"对‘燃料电池物理及化学性能的有限时间热力学分析方法'的讨论”答复

把有限时间热力学理论用于化学过程的研究,将会得到一系列新的结论,开展这方面的研究是很有意义的.文献[1]以燃料电池为例,在同时考虑化学反应及传热不可逆性的情况下,研究了燃料电池的性能界限,文献[2]指出了文献[1]计算化学反应及传热不可逆性而引起系统与有关环境的总熵产生率的错误以及由此而导致的结论所存在的问题,并进行了富有启发性的分析与讨论.但文献[2]对于系统与有关环境的总熵产生率的计算也是不正确的,由此得到的其它结论自然不能成立.本文将就此情况下系统与有关环境的总熵产生率的计算再次进行讨论,并给出电池功率和效率的有限时间热力学性能界限.