（2R,3S）—2甲基—3—羟基戊酸甲酯的手性合成

１引言烟草甲ＬａｊｓｔｏｄｅｒｍａｓｅｒｒｉｃｏｒｎｅＦａｂｒ。ｉｎｓ是一种主要危害烟草、香烟、干燥植物以及谷物、面粉的农业害虫。这种害虫在我国主要分布在淮河以南地区以及世界各地的温暖地带［‘］。（２,３Ｓ）－２一甲基一３一羟基成酸甲酯是我们设计的合成烟草甲性信息素的一个重要中间体。我们以丙快醇为基本原料合成了该化合物。丙炔醇参照文献ｌ’］方法制得２一戊炔一ｌ一醇２,催化还原条件下,炔键可被部分加氢得到（Ｑ－２一戊烯一卜醇３。在四异丙氧基钛、Ｄ－（）一酒石酸＄［Ｊ４Ａ分于筛催化条件下,顺式烯丙醇…     

隆回富硒区山银花不同花期硒分布规律研究

通过分析山银花不同花期硒含量,探讨了山银花中硒的积蓄规律与土壤硒之间的关系。选择湖南省隆回县小沙江地区加油站北和岩背村两处土壤硒含量分别为0.968 mg/kg和0.837mg/kg的山地,种植灰毡毛忍冬的两个不同品种:白云一号和金蕾一号,在花期内连续采收绿蕾期、白蕾期、白花期和金花期样本,脱水后,用电化学法测定硒含量。结果表明,白云一号和金蕾一号的绿蕾期、白蕾期、白花期和金花期硒平均含量分别为0.111、0.191、0.191、0.295 mg/kg和0.146、0.260、0.272、0.363 mg/kg,金蕾一号的硒积蓄能力优于白云一号。结论是富硒区山银花中硒的积蓄量与品种、花期密切相关,但与土壤中硒含量无明显相关性。     

粤航一号稻米及其亲本抗性淀粉含量的测定与比较

为确定航天品种功能稻米——粤航一号抗性淀粉含量,给临床观察膳食干预后果判断提供实验参考数据,并了解航天育种对该品种大米抗性淀粉含量的影响,用Goni测定方法测定了粤航一号、富硒粤航一号、长丝占、粳籼89 4种稻米的抗性淀粉含量。结果表明,粤航一号、富硒粤航一号、长丝占、粳籼89 4种稻米的抗性淀粉含量分别是(0.30±0.11)%、(0.47±0.37)%、(0.31±0.66)%、(0.36±0.62)%。可见粤航一号与亲本长丝占,及与富硒品种富硒粤航一号,和非航天品种优质大米粳籼89在抗性淀粉含量上无差异,航天育种对该品种稻米抗性淀粉生成遗传特征无影响。     

硅酸盐工业分析实验分段教学模式

工厂实地参观一基础单项实验一开放性选择实验一综合分析实验一自拟方案实验一企业挂职顶岗实习是硅酸盐工业分析实验分段教学的新模式。工厂实地参观和基础单项实验使学生掌握熟练的基本操作技能和牢固的硅酸盐工业分析知识;开放性选择实验、综合分析实验和自拟方案实验使学生真正意识到自己可以独立地解决实际问题：分段式的教学模式能培养学生的动手操作能力、综合运用知识能力、创新能力。     

捕收剂ADTB对一水硬铝石和铝硅矿物的捕收性能

研究了自制新型螯合捕收剂ADTB对一水硬铝石、高岭石和伊利石的浮选行为。单矿物浮选试验表明,该捕收剂对一水硬铝石、铝硅矿物的捕收能力差别较大,能有效分离一水硬铝石与铝硅矿物。通过动电位测试实验研究了捕收剂对矿物的吸附机理。结果表明:捕收剂在一水硬铝石表面可能是通过-COOH、-NHOH与Al-O形成双环螯合物的化学吸附,而在高岭石、伊利石表面主要是物理吸附。通过与捕收剂油酸进行比较,证明ADTB是一种较好的铝土矿正浮选捕收药剂。     

DNA结合蛋白结构域的研究进展*

本文综述了3种DNA结合蛋白结构域-螺旋一转折一螺旋、亮氨酸拉链、锌指近年来的研究进展。参考文献65篇。     

特色鲜明 见解独到——刘怀乐老师新著《中学化学教学文集》

正一本写给中学教师的好书,应植根于教学实践,有经验、有研究、有见解、有升华,既具有实践操作性,更具有教学启发性。刘怀乐老师的新著《中学化学教学文集》,一如他以前的著作,正是这样一种好书。本书具有鲜明的实践特色。文集中所讨论的问题来源于中学化学教育教学的实际,其中绝大多数内容     

化学课堂教学互动非本真的表现及对策

化学课堂教学本真的互动应该是在新课程改革的理念下,扎扎实实从学生的实际出发,让课堂活起来、让学生动起来,让课堂融入智慧和思考,让课堂充满生机和活力。是一种"唤醒"、一种"体验"、一种"视界融合"、一种"对话文化"。但是,在现实的化学课堂教学实践中,由于种种原因,仍然有些教师滥用、乱用互动教学,从而使教学互动被异化并走进了误区,越来越背离新课程教学互动的本义和真义,出现了非本真的现象,影响了新课程改革的贯彻和落实。     

CO(NH2)2-H3BO3-H2O体系相平衡研究

农作物不仅需要吸收C、H、O、N、P、K、Ca、Mg等营养元素,而且还需要吸收B、Mn、Zn等营养元素,以维持它们正常生长的需要.尿素是一种含氮量很高(46.60%)、性能很好的氮肥,而硼化合物又是一种很重要的微量元素肥料.因此,研究尿素与硼化合物间的相互作用,以得到既含氮又含硼的一种化合物,是一种很有意义的工作。目前,国外已开展了尿素与硼酸间相互作用的研究工作.研究结果表明,在一定条     

蛋白质芯片及其分析应用新进展

蛋白质芯片是一种快速、高效、高通量的蛋白质组研究新技术。目前,它已成为人们研究的热点之一。本文就近年来蛋白质芯片及其分析应用新进展做一简要的评述。     

神经化学及其研究进展

神经化学是一门新兴的交叉学科,这一学科将神经学与化学结合起来研究大脑的结构和功能,意识活动和机理等.大脑和神经中含有多种化学物质,这些物质影响着人的神经活动和情绪的变化以及健康.某些化学物质充当神经递质,它们是神经系统信息传递的介质.     

Signal Substances and their Reception in the Sexual Cycle of Marine Brown Algae

Attraction and repulsion are responses to chemical stimuli which can be received and processed even by unicellular organisms without a morphologically defined nervous system. Chemical substances trigger off a chain of events which starts with a membrane-bound signal receptor and, after a sequence of regulatory and modulatory steps, ends in the modulation of a motor effector organ. Binding of the signal substances to the receptor produces conformational changes in which the receptor subunits are mutually dependent on one another, and also leads to chemical modification of the subunits and affects their molecular activity. These interactions, together with the characteristic type of movement, result in a physiological pattern of behavior which enables the flagellated sex cells (gametes) of marine brown algae to finally locate their partners. The simple but highly specific brown algae gamete systems have been investigated structurally and their biological activity analyzed. The signal substances are mainly highly unsaturated aliphatic or cyclic hydrocarbons with unsaturated side chains (general formula e. g. C₁₁H₁₄, C₁₁H₁₆, C₁₁H₁₈). These systems also serve as a simplifying model which helps in the understanding of complex ganglionic pathways in higher living organisms where the sense organs convey information from the surroundings to the central nervous system through nerve pathways. The information is then processed and answered, via efferent pathways, as movement.     

Recording from an Identified Neuron Efficiently Reveals Hazard for Brain Function in Risk Assessment

Modern societies use a continuously growing number of chemicals. Because these are released into the environment and are taken up by humans, rigorous (but practicable) risk assessment must precede the approval of new substances for commerce. A number of tests is applicable, but it has been very difficult to efficiently assay the effect of chemicals on communication and information processing in vivo in the adult vertebrate brain. Here, we suggest a straightforward way to rapidly and accurately detect effects of chemical exposure on action potential generation, synaptic transmission, central information processing, and even processing in sensory systems in vivo by recording from a single neuron. The approach is possible in an identified neuron in the hindbrain of fish that integrates various sources of information and whose properties are ideal for rapid analysis of the various effects chemicals can have on the nervous system. The analysis uses fish but, as we discuss here, key neuronal functions are conserved and differences can only be due to differences in metabolism or passage into the brain, factors that can easily be determined. Speed and efficiency of the method, therefore, make it suitable to provide information in risk assessment, as we illustrate here with the effects of bisphenols on adult brain function.     

Recent advances in development of devices and probes for sensing and imaging in the brain

As the most important part of the central nervous system, the brain is extremely complex in structure and function. In vivo analysis of chemical signals is an essential way to investigate brain activity and function. Although functional magnetic resonance imaging(fMRI) or electrophysiology can be used to record brain activity, they are usually limited by low spatiotemporal fidelity or the difficulty of distinguishing the contributions of various neurochemicals. In addition, the development of in vivo biosensors with high selectivity and accuracy is essential to understand the roles that neurochemicals play in the brain. In this review, we focus on the development of instruments and devices for recording chemical signals in the live brain. Meanwhile,the strategies for development of electrochemical and fluorescent probes with high selectivity, high accuracy and good stability are also summarized. In particular, this review highlighted the contributions of our research group to this field. The development of techniques and probes enable us to understand the brain structure and function, and the mechanism of brain diseases, providing the solution for preventing and treating brain diseases.     

Derivatization in Liquid Chromatograhy/Mass Spectrometric Analysis of Neurosteroids

 Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview     

Derivatization in Liquid Chromatography/Mass Spectrometric Analysis of Neurosteroids

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｇａｓｃｈｒｏｍａｔｏｇｒａｐｈｙ/ｍａｓｓｓｐｅｃｔｒｏｍｅｔｒｙ (ＧＣ/ＭＳ)ａｎｄｌｉｑｕｉｄｃｈｒｏｍａｔｏｇｒａｐｈｙ/ｍａｓｓｓｐｅｃｔｒｏｍｅｔｒｙ (ＬＣ/ＭＳ) ,ｒｅｐｒｅｓｅｎｔａｔｉｖｅｓｏｆｔｈｅｈｙｐｈｅｎａｔｅｄｔｅｃｈｎｉｑｕｅｓ ,ａｒｅｓｏｍｅｏｆｔｈｅｍｏｓｔｒｅｌｉａｂｌｅａｎａｌｙｔｉｃａｌｍｅｔｈｏｄｓ ,ｗｈｉｃｈａｒｅｔｈｅｓｙｎｅｒｇｉｓｔｉｃｃｏｍｂｉｎａｔｉｏｎｏｆｔｗｏｐｏｗｅｒｆｕｌａｎａｌｙｔｉｃａｌｔｅｃｈｎｉｑｕｅｓ;…     

Analysis of biogenic amines in the brain of the American cockroach (Periplaneta americana) by gas chromatography-negative ion chemical ionisation mass spectrometry

Biogenic amines in the brain of the American cockroach have been identified and quantified by an extraction-derivatisation procedure involving their reaction with ditrifluoromethylbenzoyl chloride (DTFMB) in the aqueous phase followed by extraction into an organic solvent, hydrolysis of phenolic esters and conversion of free hydroxyl groups to trimethylsilyl (TMS) ethers and subsequent analysis by gas chromatography-negative ion chemical ionisation mass spectrometry. The molecular ion of these DTFMB-TMS derivatives carried most of the ion current which made the method highly specific and gave a potential limit of detection below the picogram level. This method establishes unequivocally that the principal amines in cockroach brain are tyramine, p-octopamine, dopamine, 5-hydroxytryptamine and noradrenaline. In contrast to mammalian nervous tissue, the other positional isomers of octopamine, together with the isomeric synephrines, are absent.     

On the interrelation between the methodologies of chemistry and physics

Aspects of the methodology and language of chemistry and physics are discussed. Chemistry defines the chemical properties of any substance from the results of its interaction with other substances using the logic of relations. Therefore, describing the properties of substances means using sets of different ideas, including ones that are opposite in meaning. Consequently, depending on the nature of reagents with respect to which properties are established, substances show chemical dualism. This dualism was established in chemistry long before the discovery of wave–particle dualism, to understand which N. Bohr proposed the complementarity principle in 1927. The methodology of natural sciences corresponds to the principle of complementarity and the need to use it to understand the world and record the results in the linguistic reality of several languages.     

HUMIC MACROMOLECULES IN NATURAL WATERS

Abstract

Humic substances are the major organic constituents of soils and sediments. They also occur in small concentrations in natural surface waters and groundwaters. They form through the breakdown of plant and animal tissues by chemical and biological processes that tend to produce complex chemical structures that are more stable than the original material from which they were derived. One of the more important characteristics of humic substances is their ability to form water-soluble and water-insoluble complexes with metal ions and hydrous oxides and to interact with clay minerals and various organic compounds such as alkanes, fatty acids, and toxic organic substances such as pesticides.     

Study on radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. I. Radiation-induced polymerization of styrene adsorbed on several inorganic substances

The radiation-induced polymerization of styrene adsorbed on silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to elucidate the effect of properties of inorganic substances on the polymerization. The rate of adsorbed state polymerization on these inorganic substances was very fast in comparison with that of bulk-state polymerization. The amount of unextractable polymer depends on the specific surface area and chemical compositions of these inorganic substances. Inorganic substances which contain aluminum as a component element are more likely to be grafted than those which consist of SiO₂ alone. The molecular weight and molecular weight distribution of unextractable polymer and extractable polymer differ from one another in each inorganic substance. In case of silicic acid anhydride, unextractable polymer has smaller molecular weight than extractable polymer. These results suggest that unextractable polymer cannot be extracted due to chemical bonds with the inorganic surface.