水介质中 aldol 反应的研究进展

文章综述了生物催化法和化学催化法催化水介质中aldol化学反应的研究进展,其中生物催化法包括酶催化和抗生素催化,化学催化法包括Lewis酸催化、碱催化和无催化剂,并展望了水介质中aldol化学反应研究的发展前景。     

生物催化及其应用研究进展

生物催化已经广泛应用于制药、食品、饮料、化妆品、造酒和香料等工业。目前,较为成熟的有酶催化和抗体催化。本文概述了酶催化和抗体催化的应用研究进展,并对其发展前景作了展望。     

心灵的催化剂

文章倡导：坚持差异性催化原则，赏识与批评、建议相结合的催化原则，有理、有据、有节的催化原则；培养一支自主管理，并会为班级管理出谋划策的班级智囊团；开展以主题班会为主阵地的班级团体心理辅导；善于抓住教育契机，通过学习、生活、活动中的现象进行及时的团体心灵的催化；不忽视个别的心灵催化，特别是对于网络成瘾症患者的学生和情感困惑型孩子的催化；充分利用学生同辈从众心理引领学生相互催化；对家长的催化；班主任教师的自我催化。坚持利用班级文化精神引领学生主动和谐发展。     

环己醇催化氧化合成环己酮的研究进展

介绍了以环己醇为原料通过催化氧化法制备环己酮的国内外现状和最新应用进展,综述了环己酮的国内外现状,介绍了硝酸铁催化氧化法、钨类催化氧法、离子液体相转移催化法等合成环己酮的研究,并对各种方法的优缺点进行了比较和讨论。展望了催化氧化环己醇合成环己酮的发展方向。     

高分子材料的催化合成

介绍了常见的与高分子合成化学反应有关的化学催化、物理催化和生物催化的类型、特点和应用。     

制备聚铁之氧化催化剂的性能评价

通过实验,探讨了目前文献报导的三种制备聚合硫酸铁所用的氧化催化剂NaNO_2、HNO_3及MnO_2的催化性能和可能的催化机制;提出了运用催化指数和氧化指数来评价催化剂性能的方法;指出进一步改善NaNO_2和HNO_3两种催化剂催化性能的方向。     

羟基氧化铁催化臭氧氧化降解苯胺废水

以实验室制备的羟基氧化铁（FeOOH）为催化剂催化臭氧氧化处理苯胺废水,对比催化臭氧氧化与单独臭氧降解苯胺的效率,实验结果表明,FeOOH催化臭氧氧化能加快对苯胺的降解速率,并且矿化程度高.说明FeOOH对臭氧氧化水中的苯胺具有明显的催化作用.探讨了氧气的进气流量、苯胺的初始浓度、水溶液的pH、催化剂的投加量等因素对催化氧化苯胺的影响.研究表明：氧气的进气流量为30L/h、初始浓度300mg/L时、pH值7.3、催化剂的投加量为2g/L、反应15min后,苯胺的去除率可达98.2%,COD的去除率可达70%.在催化体系中加入自由基捕获剂叔丁醇后,催化臭氧氧化反应明显受到抑制,间接证明了FeOOH催化臭氧氧化苯胺遵循自由基反应机理.     

汽车尾气的催化净化技术研究

随着我国对汽车排放法规的日趋严格,催化净化技术对汽车尾气的治理显得尤为重要。本文系统论述了催化净化技术的发展、类型;催化剂的组成;三效催化转化器的构成、工作过程及应用中的问题等。     

生物炭催化臭氧氧化降解金橙Ⅱ染料废水

目的:研究生物炭催化臭氧氧化降解金橙Ⅱ染料废水的效果.方法:以金橙Ⅱ模拟印染废水作为实验对象,以生物炭为催化剂,对不同条件下(金橙Ⅱ初始浓度、生物炭使用量、气流量、臭氧浓度、初始pH值、臭氧氧化时间)的生物炭催化臭氧氧化降解金橙Ⅱ的效果进行研究.结果:相对于单独臭氧氧化降解金橙Ⅱ,生物炭催化臭氧氧化降解金橙Ⅱ的效果有显著提升.生物炭催化臭氧氧化降解金橙Ⅱ的实验结果表明,通过增加生物炭使用量,提高臭氧浓度,增大气流量,在一定范围内提高初始pH值,可以提升生物炭催化臭氧氧化降解金橙Ⅱ的去除率.羟基自由基是生物炭催化臭氧氧化降解金橙Ⅱ过程中的主要活性物质.结论:生物炭催化臭氧氧化降解金橙Ⅱ染料废水具有很好的效果,金橙Ⅱ初始浓度、生物炭使用量、气流量、臭氧浓度、初始pH值、臭氧氧化时间对生物炭催化臭氧氧化降解金橙Ⅱ染料废水效果有一定影响.     

稀土(复合)氧化物在天然气催化燃烧中的作用

催化燃烧技术是一项环境友好的能源利用方式,与普通的火焰燃烧相比,催化燃烧具有起燃温度低、能耗少、燃烧稳定、净化效率高等优点.文章就稀土(复合)氧化物在天然气催化燃烧中的作用及所面临的问题进行了阐述.     

Gases as Idealized Lattices: A Rational Reconstruction of Students' Understanding of the Behavior of Gases

The main objective of this study is to establish a relationship between students' understanding of gases and its parallels in the history of science (rational reconstruction). Fifty-nine freshman students were asked to respond to a gas problem that did not require any calculations but rather conceptual understanding (due to molecular collisions, gases occupy all the available space). Before responding to the problem students were exposed to an elementary version of the kinetic theory of gases. Results obtained showed that a large proportion of the students gave explanations that approximate quite closely to an idealized form of the Lattice Theory of Gases. This theory considered molecules in gases to be arranged in the form of regular lattices, rather as if gases were highly expanded solids, and was held by most chemists until about 1860. It is concluded that some of the students' alternative conceptions about gas behavior (attractive forces between gas molecules increase as the temperature decreases) are resistant to change and recapitulate theories scientists held in the past.     

FTIR法测定隧道内不明气体

通过对襄渝铁路二线财神庙隧道施工过程中出现的不明气体,利用FTIR光谱进行分析,介绍红外光谱分析方法的产生、原理和优点.同时对隧道内的施工钻孔逸出的不明气体和隧道内的空气二者的红外光谱进行对比分析.     

Seventh grade students' mental models of the greenhouse effect

This constructivist study investigates 225 student drawings and explanations from three different schools in the midwest in the US, to identify seventh grade students' mental models of the greenhouse effect. Five distinct mental models were derived from an inductive analysis of the content of the students' drawings and explanations: Model 1, a ‘greenhouse’ for growing plants; Model 2, greenhouse gases cause ozone depletion or formation, causing the Earth to warm; Model 3, greenhouse gases, but no heating mechanism, simply gases in the atmosphere; Model 4, greenhouse gases ‘trap’ the sun's rays, heating the Earth; and Model 5, the sun's rays are ‘bounced’ or reflected back and forth between the Earth's surface and greenhouse gases, heating the Earth. Science textbooks are critiqued in light of the students' mental models and curricular and instructional implications are explored.     

混合气体各组份浓度的C程序设计

气体组份的分析在许多领域特别是在环境保护中具有重要意义，对于混合气体中各组份浓度的分析，人们提出了多种方法．章根据气体的光声效应，利用气体的光声光谱对混合气体各组份的浓度用C语言编程进行计算。     

鸡舍内有害气体的来源、危害及控制

本文从鸡舍内部分有害气体的产生和分布 ,有害气体对鸡的健康和生产性能的影响及有害气体的预防与控制等方面的研究现状及发展进行了综合论述。     

氮在碳纳米管结构变化中的作用

利用等离子体增强热丝化学气相沉积制备了碳纳米管，并用扫描电子显微镜和透射电子显微镜对生长的碳纳米管进行了表征。发现用CH4和H2制备的是空芯碳纳米管，而在反应气体中加入NH3后，生长的碳纳米管是竹节型结构的碳纳米管，表明氮在碳纳米管的结构变化过程中起到了重要的作用。根据氮对碳在催化剂中的扩散影响，分析了氮在碳纳米管结构发生变化过程中的作用。     

Secondary students’ ideas about scientific concepts underlying climate change

Abstract

We present ideas about concepts underlying climate change, held by students in years 9 and 10. Misconceptions about climate change are common among students, and may be due to misconceptions about underlying concepts. To investigate this, we developed the Climate Change Concept Inventory (CCCI), and trialed it with 229 students; corroborating findings through focus group interviews. Our interview method and data analysis methods are described. Findings included overestimation of human contributions to atmospheric carbon inputs, ultra violet radiation in sunlight, and greenhouse gases in the atmosphere. Students were unaware that CO₂ dissolves in water, and of the role of oceans in the carbon cycle. Greenhouse gases other than CO₂ were rarely known. Earth’s energy balance and black body radiation were not well understood. There were misconceptions about interactions between electromagnetic radiation and atmospheric gases; and limited understanding of carbon chemistry. The CCCI is available from the corresponding author.     

温室气体及其排放的研究

本文对主要的温室气体及其源、汇、环境效应、减排措施进行了研究。温室气体主要指CH4、CO2、N2O、CFCs等,其中CH4、N2O和CFCs不仅是温室气体,而且在平流层中会玻坏臭氧层。自工业革命以来,大气中温室气体排放源的增加及汇的降低导致了全球气候变暖,严重地威胁着人类赖以生存的环境——地球。     

n维低温强简并与完全简并理想费米气体的性质

推导了能谱为ε=aps的n维理想气体的量子态密度,内能和压强的关系,并给出了n维完全简并、低温强简并理想费米气体的化学势、内能、简并压等热力学量的普遍表达式,通过分析比较得出T趋近于0时,低温强简并各热力学量过渡到完全简并的结论.     

谐振子在高温弱简并和经典情况下的状态函数

推导出了能谱为ε=∑i=1pi22m+12mi2r2i的n维经典谐振子的态密度,由于处于n维简谐势阱中的粒子可以看作n维谐振子,进而求出了服从玻尔兹曼分布、费米分布、玻色分布的n维简谐势阱中的粒子的状态方程及各热力学函数.