化学实验中渗透绿色化学的研究

主要阐述了绿色化学在化学实验中的必要性,从绿色化学的角度出发来分析导致化学实验污染的原因以及提出了有效的解决措施,使绿色化学在化学实验中得到充分的渗透,以便更好地对环境进行保护。     

A chemical demonstration of the randomness of epoxidation of natural rubber

During the development of chemical methods for determining the epoxide content of epoxidised natural rubber (ENR) two methods were found to give results which were identical but which showed a progressive divergence from values obtained by absolute instrumental methods as the level of epoxidation increased. Statistical analysis of the sequence distribution of the epoxide groups, based on a random epoxidation, showed a good correlation between the value obtained by chemical analysis and the number of epoxide blocks rather than the number of epoxide groups. Two further instrumental methods for measuring the total epoxide content, using infra red spectroscopy and differential scanning calorimetry, were developed. Analytical procedures and calibration data are supplied. A combination of one chemical and one instrumental method can thus provide the absolute level of epoxidation and indicate whether the reaction has proceeded randomly or not, a point of crucial importance in the large scale manufacture of this material.     

实现无机及分析化学实验绿色化的探索与实践

根据绿色化学使用化学药品的原则,就如何实现无机及分析化学实验的绿色化进行了初步的探索与实践。在无机及分析化学实验教学中,要让学生树立起绿色化学思想,加强和培养学生的绿色意识、环保意识。作者结合实际教学经验,指出改进实验方法,采用微型实验、小量-半微量实验,合理安排实验项目和次序,对实验产物进行回收利用是实现无机及分析化学实验绿色化的重要途径。     

微反应器在化学化工领域中的应用

微反应器是微型化学反应系统,具有换热和传质效率高、严格控制反应时间、易于放大、安全性能好等特点。和传统搅拌反应器相比,这些特点使得微反应器在缩短反应时间、大幅度提高化学反应的转化率和产品收率等方面展现出一定的优势。但微反应器也存在易堵塞,催化剂负载、微通道的设计与制造难度大等问题。本文介绍了近年来快速发展的微反应器技术,回顾了微反应器的特点,重点探讨微反应器在化学化工领域的应用以及微反应器在精细化工和制药工业、生物化工领域的应用实例,讨论了微反应器目前存在的诸多挑战。微反应器目前是化学和化工学科的前沿和热点方向,分析表明微反应器仍然有很大的发展空间,有潜力改变化学化工前景。提出应进一步深入系统地认识微反应器内化学反应以及微通道设计的基本规律和机理,将微反应器技术引入更广泛的反应体系中,加强微反应器的集成化水平。     

有机合成实验的绿色化学探索

在有机合成实验教学中,通过优选实验项目、设计实验体系及改进实验方法等手段,达到节约环保、减少物料的使用与排放、在实验过程中引导学生树立绿色化学思想观念和增强环境保护意识的目的.     

物理化学开放型实验的实践与探索

介绍了为全校跨年级、跨专业本科生共同开设开放型实验“各品牌洗衣粉的性能比较”的选题目的和意义。通过开放实验,学生提高了解决实验问题、分析实验结果的能力,并将所学的理论知识应用到我们的日常生活中。     

拓扑学原理在化学化工中的应用

从拓扑学原理出发,引入了拓扑指数的概念,并用拓扑方法研究分子结构-理化性质、结构-活性、结构-保留及阴离子表面活性剂结构-HLB值定量关系。同时探讨了拓扑化学反应控制原理及其在合成化学与工业生产中的应用。     

Computational experiments in equation-based chemical process flowsheeting

The central computational problem in equation-based flowsheeting is the simultaneous solution of a large sparse system of nonlinear algebraic equations. SEQUEL-II, our implementation of the equation-based approach, provides a means for comparing nonlinear equation-solving techniques, in particular the techniques used for computing correction steps, for ge nerating initial guesses, and for evaluating sparse Jacobian matrices. Comparisons are made on the basis of both efficiency and reliability. On a set of fourteen process flowsheeting problems, Powell's dogleg correction step is not only very efficient, but also somewhat more reliable than the Newton step when good initial guesses are not available. Schubert's sparse Jacobian update performs very well, but Bogle and Perkins' new least-relative-change update gives improved performance, when used in connection with either the dogleg or Newton correction step. The use of a hybrid update provides a better approximation of the Jacobian than a sparse update alone, one, and so significantly improves, in terms of number of iterations, the efficiency of the dogleg correction step.     

无机及分析化学实验的教学改革研究

无机及分析化学实验是众多学院大学基础课程中最为重要的一门课程之一,如何能够更好的教授学生相关基础知识,帮助学生学习和掌握正确的实验操作和实验设计方法,是当下实验教学改革中重要的问题。     

数据挖掘在化学化工中的研究进展

随着大数据时代的到来,大量数据之下所隐藏信息的价值也越来越凸显。数据挖掘技术作为一个交叉学科,它的应用也已经涉及到了许多领域。在化学化工领域,数据挖掘所提供的算法体系,极大程度的丰富了化学化工领域的研究思路和手段。通过整合近年来数据挖掘技术在化学化工领域所取得的突破性进展,评述了数据挖掘技术在化工建模、工艺条件的优化、数据库平台的创建和安全生产方面的应用。     

数据挖掘在化学化工中的研究进展

随着大数据时代的到来,大量数据之下所隐藏信息的价值也越来越凸显。数据挖掘技术作为一个交叉学科,它的应用也已经涉及到了许多领域。在化学化工领域,数据挖掘所提供的算法体系,极大程度的丰富了化学化工领域的研究思路和手段。通过整合近年来数据挖掘技术在化学化工领域所取得的突破性进展,评述了数据挖掘技术在化工建模、工艺条件的优化、数据库平台的创建和安全生产方面的应用。     

拓扑指数在化学化工领域的研究现状

拓扑指数是定量构效关系研究领域最常用的方法之一。本文论述了拓扑指数在色谱分析、理化性质预测、对有机污染物进行生态风险评价中的应用。以及三维拓扑指数的研究现状。并对拓扑指数在化学化工领域的研究前景做了展望。     

化工库的温度湿度自动测试

本文介绍一种检测化工库温度、湿度的自动检测系统原理，并给出硬件结构框图和软件流程图。     

Two experiments for the introductory chemical reaction engineering course

This paper describes a pair of chemical reaction experiments developed for Rowan University's introductory course in chemical reaction engineering: an esterification reaction carried out in a packed bed, and a competitive reaction in which the kinetics were influenced by micromixing.

The first experiment is the esterification of ethanol and acetic acid to form ethyl acetate. Students first examine this reaction in their organic chemistry class. The experiment developed in this project re-examines this reaction from a chemical engineering perspective. For example, the reaction is reversible and equilibrium-limited, but in the organic chemistry lab, there is no examination of the kinetics. The complementary chemical engineering experiment examines the relationship between residence time and conversion.

The second experiment is a competitive system involving two reactions:

H₂BO₃⁻ + H⁺ ↔ H₃BO₃

5I⁻ + IO₃⁻ + 6H⁺ → 3I₂ + 3H₂O

The first reaction is essentially instantaneous. Thus, when H⁺ is added as the limiting reagent, a perfectly mixed system would produce essentially no I₂. Production of a significant quantity of I₂ is attributed to a local excess of H⁺; a condition in which all H₂BO₃⁻ in a region is consumed and H⁺ remains to react with I⁻ and IO₃⁻.

In the spring of 2005, for the first time, both experiments were integrated into the undergraduate chemical reaction engineering course. This paper describes the use of the experiments in the classroom and compares the performance of the 2005 students to the 2004 cohort, for whom the course included no wet labs at all.     

初谈21世纪的中国化学与化工─—一孔之见

通过对现代化学与化工特点的分析，作者对化学学科作了分类，阐述了未来化学工业的特点及工程化学学科发展的见解。     

Current progress on the chemical functionalization and supramolecular chemistry of M@C82

Since the first discovery of fullerenes in 1985, the insertion of one or more atoms into a hollow fullerene cage has been attempted. Furthermore, synthesis and extraction of metallofullerene, La@C(n), were reported in 1991. Recent successful isolation and purification of metallofullerenes have facilitated the investigation of their chemical properties. This mini-review presents a summary of the recent progress of chemical functionalization and supramolecular chemistry of M@C(82). Selective functionalization and successful structural analysis of derivatives have revealed their chemical features arising from endohedral metal doping.     

无机化学实验教学改革探索与实践

实验教学是培养学生动手能力、思维能力以及创新意识与能力的主要教学过程,在培养化学化工类专业人才中起着特殊的作用~([1]).针对处于学习方式转型期的新生,无机化学实验是化学化工类学生进入大学后接触到的第一门专业基础实验课,对培养学生良好的实验习惯起着极其重要的作用,也为后续实验课的开展及新的实验技术的引进打下基础~([2]).     

超级电容器用活性炭国产化关键化学与化工问题

超级电容器具有功率密度高、循环寿命长和安全可靠等优点,在电动汽车、轨道交通、新能源、电磁弹射和激光武器等领域已广泛应用。然而,作为超级电容器的关键电极材料——活性炭,始终未实现国产化,一直依赖从日本和韩国进口,极大地制约了国内超级电容器及其下游产业的发展。本文综述了超级电容器用活性炭的理化性能对其电化学性能的影响,介绍了国内外超级电容器用活性炭产业现状,指出了其生产过程中制约产品品质的典型传质和传热等化工问题。文章提出,应在现有活性炭基础上建立全面合理的超级电容器用活性炭指标体系,从而指导其国产化工艺开发。针对其生产工艺和装备开展仿真模拟研究,以解决国产炭材料批次稳定性和一致性的问题,保障超级电容器行业关键材料自主可控。     

煤直接液化技术发展的化学脉络及化学工程挑战

从对煤直接液化的化学本质的分析入手,讨论了煤直接液化技术发展的化学脉络及所面临的化学工程挑战。作者认为,煤直接液化技术的化学本质是煤大分子结构在热场中裂解产生自由基碎片的速率和自由基碎片加氢的速率的匹配,这两个速率的差异决定了煤浆预热、煤液化反应,甚至高温条件下产物分离等过程的特征,决定了油收率、系统中物料结焦、物料输送等行为。