高职石化类专业《化工分析》课程改革的探索与实践

论文以高职石化类专业的基础能力课程《化工分析》为研究对象,结合高职教育的特点,针对目前石化类专业《化工分析》课程存在的问题,对课程内容、教学方法与手段、考核评价标准以及校企合作等方面进行了探索性改革。密切联系石化行业背景,工学结合,提升学生的职业能力,实现校企无缝对接。

浅谈中专《化工分析》的“研究性学习”

在中专化工分析课程教学中实施“研究性学习” ,有利于培养学生的合作精神、动手能力和综合应用能力。实施“研究性学习”在选题时 ,应坚持知识性和趣味性、实践性和创造性、综合性和交叉性原则。同时要注意用好网络 ,适时辅导学生 ,妥善处理课堂教学与“研究性学习”的关系。

Prediction of pre-oxidation efficiency of refractory gold concentrate by ozone in ferric sulfate solution using artificial neural networks

An artificial neural network model was developed to predict the oxidation of refractory gold concentrate （RGC） by ozone and ferric ions. The concentration of ozone and ferric ions, pulp density, oxygen amount, leaching time and temperature were employed as inputs to the network; the output of the network was the percentage of the ferric extraction iron from RGC. The multilayered feed-forward networks were trained by 33 sets of input-output patterns using a back propagation algorithm; a three-layer network with 8 neurons in the hidden layer gave optimal results. The model gave good predictions of high correlation coefficient （R2=0.966）. The predictions by ANN are more accurate when compared with conventional multivariate regression analysis （MVRA）. In addition, calculation with ANN model indicates that temperature is the predominant parameter and ozone concentration is the lesser influential parameter in the pre-oxidation process of refractory gold ore. The ANN neural network model accurately estimates the ferric extraction during pretreatment process of RGC in gold smelter plants and can be used to optimize the process parameters.

Analysis of Amylase and Superoxide Dismutase Isozymes During the Germination Process of Emmenopterys henryi Oliv Seeds

[ Objective] The study was to understand the changes of amylase（AMY） and superoxide dismutase（SOD） isozymes during the ger- mination process of Emmenopterys henryi Oliv seeds. [ Metbod] By employing polyacrylamide gel electrophoresis method, the expressions of AMY and SOD isozymes during seed germination process were analyzed. ~ Result] The main AMY bands remained strong during the whole peri- od and a new band A2 appeared in the middle and late period of seed germination. Some new SOD bands occurred at the early stage, then be- came weak or disappeared in the middle period, and band S6 became intense in the late peried. [ Conclusion.] The expression of AMY and SOD isozyme gene has temporal difference during germination of E. henryi Oliv seeds.

STUDY OF FLOW AND TEMPERATURE IN RESIN TRANSFER MOLDING PROCESS BY NUMERICAL MODEL

A mathematical model of resin flow and temperature variation in the filling stage of the resin transfer molding (RTM) is developed based on the control volume/finite element method (CV/FEM). The effects of the heat transfer and chemical reaction of the resin on the flow and temperature are considered. The numerical algorithm of the resin flow and temperature variation in the process of RTM are studied. Its accuracy and convergence are analyzed. The comparison of temperature variations between experimental results and model predictions is carried out for two RTM cases. Result shows that the model is efficient for evaluating the flow and temperature variation in the filling stage of RTM and there is a good coincidence between theory and experiment.

A Modified Model for Flexibility Analysis in Chemical Engineering Processes

This paper discussed an extended model for flexibility analysis of chemical process. Under uncertainty, probability density function is used to describe uncertain parameters instead of hyper-rectangle, and chanceconstrained programming is a feasible way to deal with the violation of constraints. Because the feasible region of control variables would change along with uncertain parameters, its smallest acceptable size threshold is presented to ensure the controllability condition. By synthesizing the considerations mentioned above, a modified model can describe the flexibility analysis problem more exactly. Then a hybrid algorithm, which integrates stochastic simulation and genetic algorithm, is applied to solve this model and maximize the flexibility region. Both numerical and chemical process examples are presented to demonstrate the effectiveness of the method.

An Extended Algorithm of Flexibility Analysis in Chemical Engineering Processes

An extended algorithm of flexibility analysis with a local adjusting method for flexibility region of chemical processes, which is based on the active constraint strategy, is proposed, which fully exploits the flexibility region of the process system operation. The hyperrectangular flexibility region determined by the extended algorithm is larger than that calculated by the previous algorithms. The limitation of the proposed algorithm due to imperfect convexity and its corresponding verification measure are also discussed. Both numerical and actual chemical process examples are presented to demonstrate the effectiveness of the new algorithm.

Top-cited Articles in Chemical Engineering in Science Citation Index Expanded:A Bibliometric Analysis

This study aimed to identify and to analyze characteristics of top-cited articles published in the Web of Science chemical engineering subject category from 1899 to 2011.Articles that have been cited more than 100 times were assessed regarding publication outputs,and distribution of outputs in journals.Five bibliometric indicators were used to evaluate source countries,institution and authors.A new indicator,Y-index,was created to assess quantity and quality of contribution to articles.Results showed that 3828 articles,published between 1931 and 2010,had been cited at least 100 times.Among them 54% published before 1991,and 49% top-cited articles originated from US.The top eight productive institutions were all located in US.The top journals were Journal of Catalysis,AIChE Journal,Chemical Engineering Science and Journal of Membrane Science.Y-index was successfully applied to evaluate publication character of authors,institutions,and countries/regions.

化学工业出版社图书推荐

为了向广大读者提供更多实科技图书资讯 ,传送专业技术、知识和信息 ,本刊将与化学工业出版社长期合作 ,向读者推荐相关的优秀图书。化学工业出版社是一家历史悠久的中央级出版社 ,出版物涉及化学、化工、材料、环境保护、生物技术、医药科技、轻工业、工业装备、电气工程与自动化、安全科学与工程、“三农”读物等专业的专著、实用技术、工具书、教材和职业培训用书等方面 ,受到了广大科研、技术、管理人员以及大专院校师生的普遍欢迎。如您还需要了解其他图书信息 ,欢迎与本刊编辑部或化学工业出版社联系。

Ecological footprint of Gansu Province,China between 1997 and 2002:changes and inducement

The calculation of Ecological Footprint （EF） on the basis of Input-Output model （I-O model） was advanced by Bicknell, and modified and improved hy Ferng who corrected the footprint＇s aggregation to each sectors. For the lack of sufficient teehnique to deal with the trade between the research areas and the rest of the world, it it necessary to improve this method. And a dynamic analysis of the change of footprint based on I-O model, which could explore the factor impacting the footprint using the ,special advantage of I-O model, ought to be put into practice. After introducing the new method in detail, we calculate and compare the EF and the change of Gansu Province in the northwest of China in 1997 and 2002. The result shows that there was an increase of EF in 2002 caused by final domestic demand. Further; the inerement in EF export was 2.0 × 10^5 ha and 1.6 × 10^6 ha in import. The out-of- region support dropped from 22.6% to 18. 6%. We introduce three factors causing the EF change based on the character of I-O model： the productivity of the resourve which is explained by the change of resource used to obtain one unit output in a sector, the improvement of the economics and the final demand. Finally, we find that the effects of the three factors on the EF change are not identical except the industry sectors and the change of factors in the agriculture and the industry sectors works notably.

Double Moving Window MPCA for Online Adaptive Batch Monitoring

Online monitoring of chemical process performance is extremely important to ensure the safety of a chemical plant and consistently high quality of products. Multivariate statistical process control has found wide applications in process performance analysis, monitoring and fault diagnosis using existing rich historical database.In this paper, we propose a simple and straight forward multivariate statistical modeling based on a moving window MPCA (multiway principal component analysis) model along the time and batch axis for adaptive monitoring the progress of batch processes in real-time. It is an extension to minimum window MPCA and traditional MPCA.The moving window MPCA along the batch axis can copy seamlessly with variable run length and does not need to estimate any deviations of the ongoing batch from the average trajectories. It replaces an invariant fixed-model monitoring approach with adaptive updating model data structure within batch-to-batch, which overcomes the changing operation condition and slows time-varying behaviors of industrial processes. The software based on moving window MPCA has been successfully applied to the industrial polymerization reactor of polyvinyl chloride (PVC) process in the Jinxi Chemical Company of China since 1999.

Emission Characteristics of Volatile Organic Compounds from Automobile Coating Industry in Chongqing City

To fully analyze emission characteristics of VOCs （Volatile Organic Compounds） from automobile coating industry in Chongqing city, related enterprises in the city were investigated in detail. The results show that the emission of VOCs from the automobile industry in Chongqing city was approximately 20,000 t in 2012, and the contribution rate of automobile coating was 83%. Most VOCs discharged from automobile coating industry were mainly from the use of coatings, diluents, curing agents and other materials containing VOCs. During the process of automobile coating, VOCs were mainly produced during the processes of spraying and drying. Besides, VOCs are partly produced during the processes of mixing paint, gluing, waxing and repairing. The major ingredients of VOCs discharged during the process of automobile coating were methylbenzene, dimethylbenzene, trimethylbenzene, cumene, ethyl acetate, butyl alcohol, n-butyl alcohol, isobutyl alcohol, formaldehyde, butanone, acetone, cyclohexanone and methyl ethyl ketone. Besides, the ingredients of naphtha and aromatic hydrocarbon in VOCs need to be determined. The maximum OFP （Ozone Formation Potential） of the above pollutants by the typical enterprises was 900-1,300 mg/m^3. The production of SOA （Secondary Organic Aerosol） was 3,636-11,073 t/a, which didn’t include the contribution of aldehydes, ketones, ethers and esters to SOA. This research could provide scientific reference for the establishment of emission standard, control technology and management methods of VOCs from automobile coating industry that accord with economic and social development in Chongqing city.

A New Procedure to Solve the Non-Linear Reaction-Diffusion Equation

1 INTRODUCTIONThe concentration distribution of reactant in porouscatalyst pellet not only is the basis of calculating theeffectiveness factor,but also has a great significancein investigating the reaction and mass transfer in thecatalyst pellet.In principle,the concentration distri-bution and the effectiveness factor of a catalyst pelletcan be obtained by solving the reaction-diffusion equation.However,most of the differential equations haveno analytical solution except for some simple cases.The previous investigators have made great efforts to calculate the effectiveness factors of catalysts.They first obtained asymptotic solutions of effective-ness factor in the cases of the Thiele modulus φ→Oand φ→oo by means of perturbation method,thensynthesized the information of the asymptotic solu-

Probiotic Lactobacillus rhamnosus downregulates FCER1 and HRH4 expression in human mast cells

AIM:To investigate the effects of four probiotic bacteria and their combination on human mast cell gene expression using microarray analysis.METHODS:Human peripheral-blood-derived mast cells were stimulated with Lactobacillus rhamnosus (L.rhamnosus) GG (LGG),L.rhamnosus Lc705 (Lc705),Propionibacterium freudenreichii ssp.shermanii JS (PJS) and Bifidobacterium animalis ssp.lactis Bb12 (Bb12) and their combination for 3 or 24 h,and were subjected to global microarray analysis using an Affymetrix GeneChip Human Genome U133 Plus 2.0 Array.The gene expression differences between unstimulated and bacteria-stimulated samples were further analyzed with GOrilla Gene Enrichment Analysis and Visualization Tool and MeV Multiexperiment Viewer-tool.RESULTS:LGG and Lc705 were observed to suppress genes that encoded allergy-related high-affinity IgE receptor subunits α and γ (FCER1A and FCER1G,respectively) and histamine H4 receptor.LGG,Lc705 and the combination of four probiotics had the strongest effect on the expression of genes involved in mast cell immune system regulation,and on several genes that encoded proteins with a pro-inflammatory impact,such as interleukin (IL)-8 and tumour necrosis factor alpha.Also genes that encoded proteins with anti-inflammatory functions,such as IL-10,were upregulated.CONCLUSION:Certain probiotic bacteria might diminish mast cell allergy-related activation by downregulation of the expression of high-affinity IgE and histamine receptor genes,and by inducing a pro-inflammatory response.

Analysis of insidious fault activation and water inrush from the mining floor

Based on the stress field distribution rule of the mining floor under abutment pressure, we have established a simplified mechanical model, which contains multiple factors relating to activation and evolution of insidious water-conductive faults. The influence of normal and shear stresses on fault activation and effective shear stress distribution in the fault plane was acquired under mining conditions.Using fracture mechanics theory to calculate the stress intensity factor of an insidious fault front, we have derived the criterion for main fault activation. Results indicate that during the whole working face advance, transpressions are exerted on fault planes twice successively in opposite directions. In most cases, the second transpression is more likely to lead to fault activation. Activation is influenced by many factors, predominant among which are: burial depth of the insidious fault, friction angle of the fault plane, face advance direction and pore water pressure. Steep fault planes are more easily activated to induce a sustained water inrush in the face.

A ＂Trojan＂ in Climatic Change： The Urban Effect

This paper sets out the preliminary results of an experimental research plan aimed at analysing the thermal processes inherent to the urbanisation effect. Although this effect is undeniable, the extent of its impact is a matter of controversy. The results obtained in this study show both the nature of the phenomenon and its considerable magnitude. Failure to take this process into account might seriously bias any analysis of thermal evolution, the cornerstone of the climate change hypothesis.

Improved wavelet neural network combined with particle swarm optimization algorithm and its application

An improved wavelet neural network algorithm which combines with particle swarm optimization was proposed to avoid encountering the curse of dimensionality and overcome the shortage in the responding speed and learning ability brought about by the traditional models. Based on the operational data provided by a regional power grid in the south of China, the method was used in the actual short term load forecasting. The results show that the average time cost of the proposed method in the experiment process is reduced by 12.2 s, and the precision of the proposed method is increased by 3.43% compared to the traditional wavelet network. Consequently, the improved wavelet neural network forecasting model is better than the traditional wavelet neural network forecasting model in both forecasting effect and network function.

Effects of Grape Processing on Antioxidant Capacity and ESI-MS Fingerprints of Grape Products

The antioxidant capacity and changes in chemical composition of two grape varieties, the new hybrid BRS-Carmem and the Bord6 grape （Vitis labrusca） and of their products （juice, wine and vinegar） were evaluated by several techniques. The DPPH method was used to measure the antioxidant capacity, whereas, the total phenolic contents （TPC） were measured by Folin-Ciocalteau method. Overall chemical composition was also monitored by ESI-MS fingerprints and UPLC-MS analysis. For both grape varieties, the highest （and similar） antioxidant capacity and TPC were observed for the wine and vinegar samples followed by the grapes and then the juices. In addition, ESI-MS fingerprints and UPLC-MS analysis in the negative ion mode indicated substantial changes in chemical composition from grape to juice and wine, and then to vinegar.

Multidimensional CAE methods for car body structure optimization

The computer aided engineering(CAE) analysis technique has become one of the most important means in modern automobile development due to its remarkably computing capability.With the development of CAE bussiness software and intensive research on automotive development process,the CAE technique,which was only used as an auxiliary validation tool in the later product development in the past,is gradually used in each stage of product development now.Furthermore,accurate and fast analysis data can be supplied effectively.Especially in current CAE application, based on some optimization technologies such as sensitivity,feature and topology,the parametric design gradually enables a CAE engineer to be free from the condition which a convention analysis usually lags behind a design,and makes it be parallel to or even anterior to the design.Under the circumstance,the CAE resources can be maximized in each project development department,thereby promoting the project progress and quality,and creating a new philosophy of 'analysis-driven design'.