资源型城市循环经济评价指标体系研究

我国的许多资源型城市,已经面临越来越严重的资源、环境和发展的困境,通过循环经济建设改变城市的发展模式,提高城市的可持续发展能力,是近年来理论研究和实际工作中非常重要的课题。以若干城市的实践为案例,从资源、经济、生态环境和社会四个方面构建指标体系,评价和指导资源型城市循环经济建设。     

Fe–Mn/MCM-41: Preparation,Characterization,and Catalytic Activity for Methyl Orange in the Process of Heterogeneous Fenton Reaction

Active Fe-and Mn-loaded MCM-41(Fe–Mn/MCM-41),which was synthesized via a hydrothermal reaction followed by impregnation,is used in the heterogeneous Fenton reaction to degrade methyl orange(MO) in aqueous solution. The synthesized samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,N_2 adsorption–desorption isotherm analysis,Fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy. Compared with Fe/MCM-41 and Mn/MCM-41,Fe–Mn/MCM-41 showed higher activity for MO degradation and mineralization. Effects of various operating parameters,such as pH,Mn content,and H_2O_2 dosage,on the degradation process were subsequently investigated. Results of experiments on the effect of radical scavengers revealed that the degradation of MO could be attributed to oxidation by HO_·. The synergy of Fe and Mn species in the Fenton oxidation process was also explained.     

程序设计语言实验教学模式改革初探

良好的实践教学对提高学生的实践能力、创新能力及个性发展起着十分重要的作用.近年来高速发展的计算机学科对实验的更新和发展提出了较高的要求,为此我们根据近年来指导学生上机实习的经验,探索出新的计算机程序设计语言实验教学模式.     

利用API增强VB的消息处理功能

利用API增强VB应用程序的消息处理机制，通过自定义窗口程序调用API函数，采直接截获和处理信息，从而增强窗口程序的功能，实现设计的特殊要求。     

推动学习型家庭建设提高家庭教育水平探赜

学习型家庭的建设,能保障家庭幸福,促进学生健康成长,提升学生就业能力,推动学习型社会建设。要推动学习性家庭建设,就要创新学习理念,营造浓厚的家庭学习氛围;发挥父母教育作用,做到言传身教;加强对学生的引导,促进社会与家庭之间的互动,提升学生的素质和现代社会的文明程度,为学生成长成才奠定基础。     

A Synthesis,Process Optimization,and Mechanism Investigation for the Formation of Polyoxymethylene Dimethyl Ethers

Polyoxymethylene dimethyl ethers(DMM_n) are promising diesel additives. The synthesis of DMM_n from methylal(DMM) and paraformaldehyde over the NKC-9 acidic ion-exchange resin catalyst was investigated. Many unrecyclable by-products such as methyl formate, dimethyl ether and formic acid were produced in the reaction. To increase the selectivity of the desired products DMM_(3-6) and reduce the amount of unrecyclable by-products, the effects of reaction temperature, time, pressure and the molar ratio of the raw materials were evaluated through a series of single factor experiments. Experiments revealed that trace amount of water could suppress the formation of unrecyclable by-products, and the optimum initial water content(less than 2 wt%) was investigated. In addition, the synthetic process needs to go through the polyoxymethylene hemiformals intermediate stage, and then the DMM_n were obtained when polyoxymethylene hemiformals reacted with methanol. Ultimately, a possible mechanism is proposed to describe the formation of DMM_n from polyoxymethylene hemiformals in detail, in which it is revealed that the formation of carbocation intermediates is important in the reaction processes.     

教育工程认证背景下的“物理化学实验”课程改革探索

“物理化学实验”是化学相关理工科专业的一门必修专业基础课,也是该大类专业学生的一项非常重要的实践环节。本文以教育工程认证为背景,总结了现阶段该课程的教学现状和存在的课程教学问题,以此为基础,从教材编订、教学模式、科研教学结合、多媒体化教学等四个方面进行了课程改革探索,并优化了以往单一的教学评价模式,将课程各个环节的考查纳入考核范围,全方位、公平公正地评价学生的学习效果。通过这一系列的教学改革举措,激发了学生的学习积极性,教学效果显著。     

Effects of water-soluble co-solvent on properties of W/O pickering emulsions

Effects of water-soluble co-solvents(WSCs)on the properties of water/oil Pickering emulsions were investigated. Pickering emulsions were prepared in the system of 1,2,4-trimethylbenzene(TMB)/ hydrophobic silica/ water with varied concentrations of WSCs(ethanol, acetic acid and glycerin). Mean droplet diameter distributions of the obtained emulsions were studied to investigate the effects of WSCs types and concentrations. The results demonstrated that mean droplet diameter distributions decreased at first and then increased with the increase of WSC concentration. Moreover, the effect of WSC concentration on the phase inversion locus was further investigated. At the same time, infrared radiation(IR)spectrometer was used to investigate the mechanism. The results showed that the WSC attaching on hydrophobic silica changed the wettability of the particles, which facilitated the formation and phase inversion of the emulsion. The hydrogen bonds between the co-solvent groups attaching on the solid particles made a great effect on the droplet size of the emulsion and strengthened the interaction among emulsifiers. Overall, proper WSC was in favor of the stability of Pickering emulsion.     

Experimental Investigation of Hydrodynamic Characteristic of a New Rotating Stream Tray

The hydrodynamic characteristic of a new rotating stream tray(NRST) was investigated. The tests were carried out using an air–water/oxygen experimental system in a column with a diameter of 500 mm. The hydrodynamic parameters studied were dry plate pressure drop, wet plate pressure drop, weeping, entrainment, and Murphree liquid efficiency. The results showed that the NRST has excellent performance in terms of high operational flexibility. The pressure drop, weeping rate, and entrainment rate remained low even under a high-capacity operation. Correlations of pressure drop, weeping, and entrainment for the NRST were obtained by regression analysis. The results can provide some important theoretical guidance for the development of this type of trays.     

Immobilization of Aspergillus Oryzae Mycelium Pellets and Its Application in the Resolution of D, L-Alanine

Aspergillus oryzae 3042 mycelium pellets were immobilized by crosslinking method with reagents of gelatin and formaldehyde. An orthogonal design table was used to determine the optimal immobilization conditions. The L-aminoacylase activity of immobilized mycelium pellets under optimal conditions was assayed. The results show that the L-aminoacylase activity was 1 350 U·g-1. and the activity retention rate was 83%. The properties of the immobilized preparation were studied. Compared with free pellets, the appropriate pH of reaction system changed from 7.0 to 8.0, temperature changed from 52℃to 63℃, and the ranges of the optimum reaction conditions were all improved. The effect of Co2 on immobilized mycelium pellets was investigated and the favorable concentration was determined. When the immobilized preparation was used for the resolution of D, L-alanine in a packed bed reactor with 10 mm in diameter, 200 mm in height, the operational stability was increased, and the half-life period was 53 d. Thermal stability analysis shows that the immobilized pellets were more stable than the free pellets.