2 nd Mercosur Congress on Chemical Engineering 4 th Mercosur Congress on Process Systems En

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2 nd Mercosur Congress on Chemical Engineering 4 th Mercosur Congress on Process Systems En

DEVELOPMENT OF A SIMULATION TOOL TO ASSESS APETROLEUM COMPANY SALES & OPERATION PLANNING Luiz Cláudio M. Paschoal1*, Daniel V. Chiarini2, Ivan de Pellegrin2, Juliana S. G. Yonamine31 Gerência de Distribuição, Logística e Transporte CENPES – PETROBRAS2Grupo de Produção Integrada COPPE – Universidade Federal do Rio de Janeiro3COPPEAD - Universidade Federal do Rio de JaneiroAbstract.It is known that steady-state and dynamic simulation are important tools for representingcontinuous processes. Event driven simulation has the same role for discontinuous processes as those ofdiscrete manufacturing or logistics operations. Nowadays many authors are defending the combinedutilization of simulation with optimization techniques. It makes possible to evaluate the optimal solutionfound using simulation models or to optimize specific points of the processes during the simulation phase.This paper discusses the development of an event driven simulation model. It will be used with optimizationtools (LP and MILP) to assess the Sales and Operations Planning of a petroleum company. The input datacome from the petroleum allocation system. The goal of this solver consists of determining a supply,transport, production and distribution logistics schedule to minimize the total cost to satisfy end-productdemand. The simulation model represents the logistics operations from oil tankers arriving to coast terminalsto the fuel products distribution to the local markets. The pipelines, bases and refineries are also represented.Definition of the level of the operations details is critical since all supply chain is been simulated. Thesimulation is run subject to supply limitations, transformation constraints, transportation mode, capacities,stock limitations and other logistic constrains. The user will change these properties that characterize thesimulation scenario using a user friendly interface when the tool development ends. As a first step thesimulation of operations in São Paulo region was made. This region comprises four refineries, five bases andtwo coast terminals. The pipeline network is the most complex of PETROBRAS system. The results werevalidated against 2002 operation data and the model showed good agreement with reality. The next step is toexpand the model to cover the whole country and create the user interface. To sum up the combination ofboth techniques allows evaluate the actual feasibility of supply planning considering all operationsrestrictions and variability of the logistic network.Keywords: Event-Driven Simulation, Sales & Operations Planning, Logistics Operations.1. IntroductionOne of the first and most fruitful applications of operations research was for the petroleum industry. It was a linear programming based optimization tool. It comprises the optimization of oil extraction, refining, blending and distribution. The objective function was the maximization of the profits considering refineries configurations with constrains and the costs of crude production, transport and utilities. Since then many others works has been presented using optimization techniques for oil and gas industry problems (Neiro and Pinto, 2003, Lasschuit and Thijssen, 2003, Aires et al., 2004).Other application that became very important in industrial systems was the event-driven simulation. It is used to representing a portion of the real world, such that experiments in the simulation model can predict what will happen in the reality (Hollocks, 1992). Basically, a simulation model gives support to the decision-making, allowing the reduction of risks and costs involved in a process (Vieira, 2004). It is used to reproduce the material flux in a supply chain or in manufacturing processes. It takes into account not only the restrictions of recourses but also the stochastic characteristics of the events.* To whom all correspondence should be addressed.Address: PETROBRAS/CENPES – Cidade Universitária Quadra 7 Sala 9109, 21941-598 Rio de Janeiro – Brazil E-mail: lclaudio@.brIn general linear programming tools are utilized to identify best values for a set of decision variables (April et al., 2004). They find the optimal operation point. But they are unable to deal with the uncertainties of many real world problems. The event-driven simulation is used to assess operations considering these uncertainties and the complexity of the process.Many authors (Azadivar, 1999; Fu et al., 2000; April et al., 2003; Cheng and Duran, 2003) are trying to combine optimization and simulation techniques in the same tool. The objectives are:•Include stochastic variables in optimization problems;•Support simulation in specific points where decisions should be made to contour problems that arise because of the variability considered;•Evaluate the real feasibility of the results of optimization process.Nevertheless the efforts realized, there is no available technique that can be commercially used until now.Bush et al. (2003) also suggested the utilization of a combination of the two techniques but using different tools. The intention was to obtain the more feasible solution for barge transportation in the Mississipi River. This solution considers aspects related to time and sequencing of operations. Figure 1 shows the logic utilized by authors to solve their problem.Fig. 1. Flow between Simulation and Optimization (Bush et al., 2003)2. Petroleum Supply ChainThe Oil & Gas industry is vertically integrated dealing with a very large range of activities extending from petroleum and gas exploration to refining and distribution. Figure 2 illustrates a high level view of petroleum supply chain. The crude can be bought or produced in the company’s field s. It needs to be transported to the refineries to be transformed in fuels and others products. Mainly two modals are utilized for its transportation: oil tankers and pipelines. After being produced the fuels are distributed by a pipeline network to the depots and to coast terminals. In these terminals ships transport the products to distant markets.The major companies that have several refineries actuating in regions closer to each other used to develop Sales & Operations Planning that balances market demand with resource capability. This planning takes in account the influences and synergies between the assets of the company considered. According to Hill (2003) the plans consider projections made by the sales and marketing departments, the resources available from manufacturing, engineering, purchasing and finance, and are directed toward hitting the company’s objectives. They are done on an aggregate level and cover a sufficient time to ensure that the necessary resources are available.Fig. 2. Petroleum Industry Supply ChainWithout a reliable Sales & Operation Planning, companies are missing a vital link between the longer-range business strategy and the operational activities that must support the strategy.PETROBRAS utilizes an in-house optimization tool, PLANAB, to define its Sales & Operations Planning with the optimal balance between demand and resources. PLANAB is a linear programming tool that incorporates an model with 11 refineries and its 64 process units, 80 available crude, 25 final and 50 intermediate products, 13 terminals, 62 pipelines and 20 market regions. But its necessary to assure that the plan is enough robust to accommodate the uncertainties not considered in the optimization process like, for instance, noprogrammed shutdowns in pipelines or process units, delays in the ships arrival and changes in market demand. So PETROBRAS and COPPE/GPI began a project to develop a simulation model to assess the company Sales & Operations Planning generated using PLANAB. The idea is to follow the logic suggested by Bush et al. (2003) and showed in Figure 1.3. Simulation ModelThe model was developed in the commercial tool Arena Professional Edition 5.0. It was choose to focus in the logistics operations of São Paulo region. In this region is produced and consumed almost 60% of brazilian demand of fuels. It has also the most complex pipeline network of the PETROBRAS system. Figure 3 gives a view of PETROBRAS assets in the region where there are 4 refineries, 5 depots, 2 coast terminals and the pipeline network the installations with each other and with the local markets. A good explanation of PETROBRAS operations in the region is provided by Neiro e Pinto (2003).Fig. 3. PETROBRAS system in São Paulo regionChiarini et al. (2004) describe the logic utilized in the model. It was divided in two sections: crude supply and products distribution. The refineries that transform the petroleum into fuels connect the sections. It was necessary to simplify as much as possible the representation since the PETROBRAS supply chain incorporates too many process and activities. The various types of crude were grouped in families regarding to its properties. The defined crude families were Marlim (heavy brazilian crude), RAT Craq (crudes that produce crackable atmospheric residuum), BTE (low sulfur crudes), Injeção (condensates) and Asfáltico (crudes that yield asphalt). The products were also grouped. The model works with the following product groups: LPG, gasoline, kerosene,diesel, fuel oil and asphalt. The refineries are modeled as “black boxes” that converts each crude family in groups of products following a predefined conversion factor.The variability was considered in the frequency of oil tankers arrivals in terminals and volume of crude transported, in the markets demands and the availability of resources.Three important points of decision are the order of pipelines utilization, since they are all connected in a network and transport different crudes or products following an programming of the batches, the definition of refineries campaigns based in the crude stock and how to dispatch the products to the various markets. Logic algorithms were created for each of them (Chiarini et al., 2004).4. Model ValidationThe model development was based in the operations realized in 2002. So the first validation was against 2002 operation data. Tables 1 and 2 show the differences between the model results and operation data collect for crude consumption and products yield in each refinery.Considering petroleum processing, the greater difference was in the consumption of Asfáltico crude in REPLAN. The magnitude of the difference can be explained by the little quantity of this kind of crude processed in the refinery. As the consumption is small, any difference in volume represents a great relative deviation.Table 1. Relative deviation of crude consumptionCRUDE REVAP REPLAN RECAP RPBCMarlim -0,9% -1,7% -1,1%Rat Craq 2,0% 2,5% -0,4% 3,0%Asfáltico 13,8%Injeção 1,8% 4,0% 2,1% 3,3%BTE -2,0% -1,2% -2,3%Analyzing products yields it is possible to notice that all differences were acceptable showing good agreement between the model and the reality.Table 2. Relative deviation of products yieldPRODUCTS REVAP REPLAN RECAP RPBCLPG -0,4% -0,4% -0,4% -0,3%Gasoline -0,2% -0,5% -0,5% -0,3%Kerosene 0,0% 0,3%Diesel -0,3% 0,0% 0,2% -0,1%Fuel Oil -0,5% -0,6% 0,0% -0,7%Asphalt 0% -1%Similar conclusion can be obtained by analysis of the pipeline utilization showed in Table 3. The greatest relative deviation was -12,8% for the pipeline with the lesser utilization.Table 3. Crude pipelines utilizationPIPELINE MODEL 2002 DATASão Sebastião – Guararema 86,6% 90,6%Guararema – REVAP 32,7% 37,5%Guararema – REPLAN 86,2% 85,6%São Sebastião – Cubatão 82,3% 77,6%Cubatão – RECAP 90,0% 88,0%Cubatão - RPBC 64,3% 57,7%By other side, the average crude inventory in each refinery showed poor results for model calculation. This is presented in Table 4. Part of the difference was relative to the initial inventory level defined in the model input data. But other part was due to the utilization of the same time for crude tank preparation, relative to drainage and chemical analysis, in all refineries not considering historical data. This problem did not invalidate the analysis made with the model, but indicates that this part of the system should be better modeled to allow conclusions over crude inventory management. That is an advantage of simulation models since the comparison with actual operations indicates clearly where should be spent more time to improve the representation of the system.Table 4. Relative deviation of average crude inventoryREVAP REPLAN RECAP RPBCTotal Crude 11,9% 22,9% 44,6% 7,8%The validation described above indicates that model developed represents well what occurred in past with the logistic system. It doesn’t say anything about how the model will work when simulating the future in situations significantly different from the past modeled. It is necessary to test the model running different scenarios and fell like it reacts to each of them. So the model was tested against a possible future scenario with brazilian exploitation of petroleum following its current trend.It was considered an increase in production of Marlim crude with an equal decrease in the volume of imported crudes. As expected the yield of light products decreased and the production of fuel oil increased. This happen because Marlim is heavier than the imported oils and the refineries cannot maintain the same yield profile without modifications in its hardware. It was not more possible balance markets demand with fuel production and the number of stock-outs increased as can be seen in Figure 4 for two depots of the region. The solution is to transfer or import light products to São Paulo and increase exportation of fuel oil to avoid the saturation of its tankage in the refineries.The answer of the model was the expected by PETROBRAS experts. This confirmed that it is possible to use the model developed to assess the company supply chain. Nevertheless it is necessary to make more efforts to improve its “intelligence” level. This will afford to reach an equilibrated solution from an unbalanced initial situation without too many human interventions.Fig. 4. Stock-out of products5. ConclusionsAs showed the Sales and Operations Planning provides a single, integrated and communicated company plan that balances the forecast market demand, the purchase of raw materials and the available resources. It needs to be realistic and achievable. But the optimization tools utilized to generate the plan cannot guarantee that it will really be achievable because this technique does not consider the uncertainties of the processes. The utilization of event-driven simulation fill this blank and allow to assess the plan generated taken into account all variability. This motivates PETROBRAS to develop joined with COPPE/GPI an simulation tool to be used in conjunction with PLANAB to make its Sales and Operations Planning more robust.The development of a pilot project to simulate PETROBRAS operations in São Paulo region showed that the model created has a great potential to be the base of the proposed tool. The next step will be feed the simulation model with PLANAB output data. The variability will be determined using historical operation and market data. In this phase the most important task will be correlate the simulation output with the reliability degree of the Sales and Operations Planning generated. The simulation modules with more influence over the success of the plan will be more detailed where necessary. But it is important to maintain the model as simple as possible avoiding increases too much its complexity. After that the model will be expanded to represent all downstream operations of PETROBRAS in the country. A user-friendly interface should be designed to really transform the simulation model in a logistic planning tool for the company.ReferencesAires, M., Lucena, A., Rocha, R., Santiago, C., Simonetti, L. (2004). Optimizing the Petroleum Supply Chain at PETROBRAS. In Proceedings of the 2004 ESCAPE. Oporto, PortugalApril, J., Glover, F., Kelly, J., Laguna, M. (2003). Pratical Introduction to Simulation Optimization. In Proceedings of the 2003 Winter Simulation Conference. New Orleans, USA, 71.April, J., Better, M.,Glover, F., Kelly, J. (2004). New Advances and Applications for Marrying Simulation and Optimization.In Proceedings of the 2004 Winter Simulation Conference. Washington, USA, 80Azadivar, F. (1999). Simulation Optimization Methodologies. In Proceedings of the 1999 Winter Simulation Conference.USA, 93.Bush, A., Biles, W. E., DePuy, G. W. (2003). Iterative Optimization and Simulation of Barge Traffic on an Inland Waterway.In Proceedings of the 2003 Winter Simulation Conference. New Orleans, USA, 1751.Cheng, L., Duran, M. A. (2003). World-Wide Crude Transportation Logistics: a Decision Support System Based on Simulation and Optimization. In Proceedings Foundations of Computer-Aided Process Operations 2003. 187 Chiarini, D., V., Yonamine, J. S. G., Pereira, B. C., Caulliraux, H. M., Pellegrin, I., Paschoal, L. C. M., (2004).Desenvolvimento de um Modelo de Simulação para Análise da Cadeia de Suprimentos de Petróleo e Distribuição de Derivados da PETROBRAS na Região de São Paulo. Anais da Rio Oil & Gas Expo and Coference 2004. Rio de Janeiro, BrazilFu, M. C. et al. (2000). Integrating Optimization and Simulation: Research and Pratice. In Proceedings of the 2000 Winter Simulation Conference. USA, 610Hill, A. V. (2003). The Encyclopedia of Operations Management Terms. University of Minnesota. Minneapolis, USA Hollocks, B. (1992). A Well-Kept Secret: Simulation in Manufacturing Industry Review. OR Insight. 5 ,(4), 12 Lasschuit, W., Thijssen, N. (2003). Supporting Supply Chain Planning and Scheduling Decisions in the Oil & Chemical Industry. In Proceedings Foundations of Computer-Aided Process Operations 2003. 37Neiro, S. M. S., Pinto, J. M. (2003). Supply Chain Optimization of Petroleum Refinery Complex. In Proceedings Foundations of Computer-Aided Process Operations 2003. 59Vieira, G. E. (2004). Ideas for Modeling and Simulation of Supply Chains with ARENA. In Proceedings of the 2004 Winter Simulation Conference. Washington, USA, 1418。

用液质法检测水和土中的草甘膦及草铵膦

Journal of Chromatography A,1081(2005)145–155Residue determination of glyphosate,glufosinate and aminomethylphosphonic acid in water and soil samples by liquidchromatography coupled to electrospray tandem mass spectrometryMar´ıa Ib´a˜n ez,´Oscar J.Pozo,Juan V.Sancho,Francisco J.L´o pez,F´e lix Hern´a ndez∗Research Institute for Pesticides and Water,University Jaume I,E-12071Castell´o n,SpainReceived11February2005;received in revised form3May2005;accepted17May2005AbstractThis paper describes a method for the sensitive and selective determination of glyphosate,glufosinate and aminomethylphosphonic acid (AMPA)residues in water and soil samples.The method involves a derivatization step with9-ﬂuorenylmethylchloroformate(FMOC)in borate buffer and detection based on liquid chromatography coupled to electrospray tandem mass spectrometry(LC–ESI-MS/MS).In the case of water samples a volume of10mL was derivatized and then4.3mL of the derivatized mixture was directly injected in an on-line solid phase extraction(SPE)–LC–MS/MS system using an OASIS HLB cartridge column and a Discovery chromatographic column.Soil samples were ﬁrstly extracted with potassium hydroxide.After that,the aqueous extract was10-fold diluted with water and2mL were derivatized.Then, 50␮L of the derivatized10-fold diluted extract were injected into the LC–MS/MS system without pre-concentration into the SPE cartridge. The method has been validated in both ground and surface water by recovery studies with samples spiked at50and500ng/L,and also in soil samples,spiked at0.05and0.5mg/kg.In water samples,the mean recovery values ranged from89to106%for glyphosate(RSD<9%),from 97to116%for AMPA(RSD<10%),and from72to88%in the case of glufosinate(RSD<12%).Regarding soil samples,the mean recovery values ranged from90to92%for glyphosate(RSD<7%),from88to89%for AMPA(RSD<5%)and from83to86%for glufosinate (RSD<6%).Limits of quantiﬁcation for all the three compounds were50ng/L and0.05mg/kg in water and soil,respectively,with limits of detection as low as5ng/L,in water,and5␮g/kg,in soil.The use of labelled glyphosate as internal standard allowed improving the recovery and precision for glyphosate and AMPA,while it was not efﬁcient for glufosinate,that was quantiﬁed by external standards calibration.The method developed has been applied to the determination of these compounds in real water and soil samples from different areas.All the detections were conﬁrmed by acquiring two transitions for each compound.©2005Elsevier B.V.All rights reserved.Keywords:Glyphosate;Glufosinate;AMPA;Water;Soil;Liquid chromatography;Electrospray interface;Tandem mass spectrometry;Derivatization1.IntroductionGlyphosate[N-(phosphonomethyl)glycine]and glufos-inate[ammonium dl-homoalanin-4-(methyl)phosphinate] are broad spectrum,nonselective,post-emergence herbicides extensively used in various applications for weed control in aquatic systems and vegetation control in non-crop areas. Aminomethylphosphonic acid(AMPA)is the major degra-dation product of glyphosate found in plants,water and soil ∗Corresponding author.Tel.:+34964728100;fax:+34964728066.E-mail address:hernandf@exp.uji.es(F.Hern´a ndez).[1].Chemical structures of these phosphorus-containing her-bicides are given in Fig.1.Due to the extensive worldwide use of these compounds and the restrictive regulations for water in the European Union,very sensitive methods for the determination of pes-ticide residues are required.However,the determination of these two herbicides at the sub␮g/L level is difﬁcult due to their ionic character,low volatility,low mass and lack of chemical groups that could facilitate their detection.Even more difﬁcult can result the residue determination in soil at low concentration levels(e.g.below0.1mg/kg),due to the complexity of this matrix sample.Most methods developed0021-9673/$–see front matter©2005Elsevier B.V.All rights reserved. doi:10.1016/j.chroma.2005.05.041146M.Ib´a ˜n ez et al./J.Chromatogr.A 1081(2005)145–155Fig.1.Chemical structures of glyphosate,AMPA and glufosinate,and derivatization reaction with FMOC.R:H or alkyl group.until now require derivatization procedures to enable analy-sis by gas chromatography (GC)or high-performance liquidchromatography (HPLC).GC/MS methods involved deriva-tization with different reagents [2–8]to confer volatility to the analytes.Normally,there is quite a lot of sample manip-ulation,and the methods are time-consuming and tedious.Physicochemical characteristics of these compounds ﬁt better with LC analysis,although the lack of adequate chem-ical groups (e.g.chromophores,UV absorption,ﬂuorogenics)hamper their measurement by conventional detectors.For these reasons,both pre-column and post-column derivatiza-tion procedures have been employed.Pre-column procedures are based mainly on derivatization with 9-ﬂuorenylmethyl chloroformate (FMOC)[9–15]to form ﬂuorescent deriva-tives (improve detection)and/or to reduce the polar character of the analytes facilitating the chromatographic retention.In post-column procedures,the most common reaction is with o-phthalaldehyde (OPA)and mercaptoethanol [16]or with OPA and N ,N -dimethyl-2-mercaptoethylamine [17].Nor-mally,HPLC has been used in combination with ﬂuorescence detection after derivatization [11–17],although in a few cases glyphosate has been determined directly by ion chromatogra-phy (IC)with UV detection [18]or suppressed conductivity detection [19],but with limited sensitivity.The potential of capillary electrophoresis combined with mass spectrometry [20]and with indirect ﬂuorescence detection [21]has also been explored,although the lack of sensitivity and/or selec-tivity of these techniques together with the difﬁculty for preconcentrating the analytes,limited their application in the ﬁeld of residues.In our research group,we have developed efﬁcient and selective methods based on the use of coupled-column liquid chromatography (LC–LC),which was proved to be an excel-lent way of minimizing sample treatment and improving sen-sitivity in a variety of sample matrices,as water,soil,fruit and vegetables [11,13–15,22].However,the use of conventional ﬂuorescent detection limited the sensitivity required in pesti-cide residue analysis,and also hampered the unequivocal con-ﬁrmation of the residues detected,which nowadays is widely accepted that has to be reached by MS techniques.Searching a method that could satisfy the requirements of sensitivity and selectivity,and unequivocal conﬁrmation of glyphosate in water,the use of MS spectrometric techniques in combina-tion with LC has been investigated by several groups.Thus,IC has been applied,due the ionic character of this analyte,coupled to MS with electrospray interface [23],while RPLC has been used in combination with ICP-MS with P detection [24].However,the sensitivity reached with these techniques was not sufﬁcient.Lee et al [9]obtained better results with the combination LC–MS.In this case,the molecular ions of the derivatized glyphosate,AMPA and glufosinate,as well as a fragment ion of each compound,were monitored in negative ionisation mode obtaining detection limits around 0.1␮g/L.The use of isotope-labelled glyphosate as inter-nal standard minimised derivatization variations and matrix effects.However,although MS based methods could be con-sidered as highly selective methods,the occurrence of false positives might be still possible mainly in the analysis of rel-atively dirty samples,as some interferences can share the same MS properties as the analyte.This may also occur in water sample analysis as it has been reported in some papers,producing constructive discussions on this subject [25].The improved sensitivity and selectivity of tandem MS make this technique ideal for the trace level determination of polar and/or ionic pesticides in water by LC–MS/MS meth-ods,as it has been proved in our laboratory [26–27].This tech-nique was also applied several years ago to the determination of glyphosate and AMPA in water [10],although considerable variation was observed caused by irreproducibility in deriva-tization and fragmentation.4-mL volume was passed through the SPE cartridge,claiming detection limits for glyphosate and AMPA around 0.03␮g/L.When dealing with more complex matrices,such as soil samples,an important loss in the sensitivity can occur a con-sequence of the ionisation suppression from the co-extracted components of the matrix,hampering correct quantiﬁcation.This matrix-effect depends on the analyte-sample combina-tion.Different approaches have been used either to minimize or to correct the matrix effect,such as increasing the sample pretreatment,performing matrix-matched calibration,using an isotope labelled standard or simply diluting the sample [28].Thus,the labeled glyphosate has been used as internal standard for the LC–MS determination of this herbicide [9].Conﬁrmation of the identity of residues in unknown sam-ples is of utmost importance in order to avoid reporting falseM.Ib´a˜n ez et al./J.Chromatogr.A1081(2005)145–155147positives.Recently,the European Union has adopted the con-cept of identiﬁcation points(IPs)as quality criterium for the conﬁrmation of contaminant residues[29].For compounds with an established MRL,a minimum of three IPs is required for satisfactory conﬁrmation of the compound identity.When LC–MS/MS technique is used,the monitoring of two MS/MS transitions,ing one precursor ion and two product ions, allows to earn four IPs,fulﬁlling the requirements of this cri-terium[25].The aim of this paper is to develop a rapid and robust method for the determination of low concentrations of glyphosate,its principal degradation product,AMPA,and glufosinate in water and soil by SPE–LC–ESI-MS/MS,that fulﬁl the requirements of excellent sensitivity and unequiv-ocal conﬁrmation of the residues detected according to the European Union guidelines.Following the most widely accepted criteria,four IPs will be achieved,thus avoiding the possibility of reporting false positives.2.Experimental2.1.ChemicalsGlyphosate(98%),glufosinate(99%)and AMPA(99%) reference standards were purchased from Dr Ehrenstorfer (Augsburg,Germany),Riedel-de-H¨a en(Seelze,Germany) and Sigma(St Louis,MO,USA),respectively.Isotope-labeled glyphosate(1,2-13C,15N),used as surrogate inter-nal standard(IS),was purchased from Dr Ehrenstorfer. Analytical reagent-grade disodium tetraborate decahydrate was obtained from Scharlab(Barcelona,Spain)and9-ﬂuorenylmethylchloroformate(FMOC-Cl)was purchased from Sigma.Reagent-grade hydrochloric acid,formic acid, potassium hydroxide(KOH),acetic acid(HAc)and ammo-nium acetate(NH4Ac)as well as LC-grade acetonitrile were purchased from Scharlab.LC-grade water was obtained by purifying demineralised water in a Nanopure II system(Barn-stead Newton,MA,USA).Standard stock solutions were prepared dissolving approx-imately50mg powder,accurately weighted,in100mL of water obtaining aﬁnal concentration of approximately 500mg/L.A50-mg/L composite standard was prepared in water by mixing and diluting the individual standard stock solutions.Standard working solutions for the LC–MS/MS analysis and for fortiﬁcation of samples were prepared by dilution of the50-mg/L composite standard with water.All standard solutions were stored in nonsilanized glass.The isotope-labeled glyphosate was purchased as1.1mL of100-␮g/mL stock solution in water.A11-␮g/mL stan-dard solution was prepared by dissolving1.1mL of the stock solution in10mL of water.Standard working solutions were prepared by diluting the intermediate standard solution with water.Solutions of5%borate buffer(pH approximately9)in HPLC-grade water and solutions containing12,000mg/L of FMOC-Cl in acetonitrile were used for the derivatization step prior to the analysis.2.2.InstrumentationFor the analysis of water samples,the mass spectrometer was interfaced to a LC system based on a233XL autosam-pler with a loop of4.3mL(Gilson,Villiers-le-Bel,France) and2pumps:an Agilent1100(Agilent,Waldbron,Germany) binary pump used to condition and wash the cartridge(P-1) and a Waters Alliance2695(Waters,Milford,MA,USA)qua-ternary pump used for the chomatographic separation(P-2), as can be seen elsewhere[24].The SPE preconcentration was performed using an Oasis HLB cartridge,20mm×2.1mm i.d.(Waters),as C-1.For the LC separation,a Discovery col-umn C18,5␮m50×2.0mm i.d.(Supelco,Bellefonte,PA, USA),was used as C-2.Mobile phase consisted of water pH 2.5(adjusted with formic acid)in P-1,and mixtures of aque-ous5mM acetic acid/ammonium acetate(pH4.8)water and acetonitrile in P-2.For the analysis of soil samples,the mass spectrometer was directly interfaced to the Waters Alliance2695(Waters) quaternary pump.The mobile phases and the column used were the same as in the case of water samples.A Quattro LC(quadrupole-hexapole-quadrupole)mass spectrometer(Micromass,Manchester,UK)with an orthog-onal Z-spray-electrospray interface was used.Drying gas as well as nebulising gas was nitrogen,generated from pressur-ized air in a NG-7nitrogen generator(Aquilo,Etten-Leur, NL).The nebuliser gasﬂow was set to approximately80L/h and the desolvation gasﬂow to800–900L/h.Datastation operating software was MassLynx v4.0.For operation in MS/MS mode,collision gas was Argon 99.995%(Carburos Metalicos,Valencia,Spain)with a pres-sure of approximately1×10−3mbar in the collision cell. Capillary voltage of3.5kV was used in positive ionization mode.The interface temperature was set to350◦C and the source temperature to120◦C.Dwell times of0.17s/scan were chosen.2.3.SPE procedureThe conditioning of the Oasis cartridge was performed with LC-grade water at pH2.5at aﬂow-rate of1mL/min for7min.An aliquot of4.3mL of water sample was pre-concentrated(1mL/min)into the cartridge and washed with acidiﬁed LC-grade water during4min.After washing,the sample was transferred in backﬂush mode to the C-2column and a gradient in P-2started.2.4.LC procedureTo perform the chromatographic separation,the gra-dient used in P-2was water5mM HAc/NH4Ac(pH 4.8)–acetonitrile,where the percentage of organic modiﬁer was changed as follows:0min,10%;5min,10%;5.1min,148M.Ib´a˜n ez et al./J.Chromatogr.A1081(2005)145–15590%;9min,90%;9.1min,10%;14min,10%.The chro-matographic separations were completed within20min. 2.5.Sample procedureThe derivatization procedure was based on Sancho et al. [14,15](see Fig.1),with slight modiﬁcations.2.5.1.Water samplesGround and surface water samples were collected in plas-tic bottles from different sites of the Valencian Mediterranean region and stored in a freezer at−18◦C until analysis.Ten millilitre of water sample was introduced into a glass tube together with100␮L of isotope-labeled glyphosate standard (110␮g/L).Samples were derivatised by adding0.6mL of 5%borate buffer(pH9)followed by0.6mL of FMOC-Cl reagent(12000mg/L),and allowing the reaction to take place overnight at room temperature.After that,samples wereﬁltered through a0.45␮m syringeﬁlter and acidiﬁed with hydrochloric acid until pH1.5.Finally,4.3mL of the acidiﬁed derivatized samples were directly injected into the SPE–LC–ESI-MS/MS system.Fortiﬁcation of surface or ground waters for recovery experiments was performed by adding1mL of5or50ng/mL mixture solutions to100mL of blank water sample in order to yield fortiﬁcation levels of50or500ng/L,respec-tively.2.5.2.Soil samplesSoil samples was collected from a public garden,sus-pected to have been contaminated by glyphosate.Air-dried soil samples were homogenized and5.0g subsamples were transferred to centrifuge tubes(50mL).Samples were extracted by shaking with0.6M KOH(10mL)on a mechan-ical shaker for30min,and then centrifuged at3500rpm for 30min.The alkaline sample extracted was separated and neu-tralized by adding drops of HCl6M and0.6M until pH7, approximately.After that,the neutralized supernatant was 10-fold diluted with HPLC-grade water.The derivatization step was performed as follows:2-mL of the10-fold diluted supernatant was pipetted into a glass tube together with 120␮L of the labelled internal standard(1.10mg/L),120␮L of5%borate buffer(pH9)and120␮L of FMOC-Cl reagent (12000mg/L).The tube was swirled and left overnight at room temperature.After that,samples wereﬁltered through a0.45␮m syringeﬁlter and acidiﬁed with hydrochloric acid until pH1.5.Finally,50␮L of the acidiﬁed deriva-tized extract was directly injected into the LC–ESI-MS/MS system.Fortiﬁcation of soil samples for recovery experiments was performed by adding1mL of250ng/mL or2500ng/mL mix-ture solutions to5.0g of blank soil sample in order to yield fortiﬁcation levels of0.05mg/kg or0.5mg/kg,respectively. Samples were equilibrated for1h prior to extraction.AMPA and glyphosate were quantiﬁed using isotope labelled glyphosate as internal standard,in both water and soil samples.In the case of glufosinate,quantiﬁcation was performed with external calibration.2.6.Validation studyLinearity of the method was evaluated analysing eight standard solutions by duplicate,in the range25–5000ng/L for water samples,and in the range1–500␮g/L for soil extracts.Precision(repeatability,expressed as relative standard deviation,in%)and recoveries were determined within day by analysing fortiﬁed blank samples in quintupli-cate.This experiment was performed at two spiking lev-els:50and500ng/L in water,and0.05and0.5mg/kg in soil.The limits of detection(LOD),deﬁned as the lowest concentration that the analytical process can reliably dif-ferentiate from background levels,were obtained when the signal was three times the average of background noise in the chromatogram at the lowest analyte concentration assayed.The limits of quantiﬁcation(LOQ)were estab-lished as the lowest concentration assayed and validated, which gave satisfactory recovery(70–120%)and precision (<15%RSD).The speciﬁcity of the method was evaluated by analysing a blank procedure,a processed blank sample,and a blank sam-ple spiked at the lowest fortiﬁcation level assayed(LOQ),i.e. 50ng/L in water and0.05mg/kg in soil.Under these condi-tions,the response obtained for both the blank procedure and the blank samples should not exceed30%of the response corresponding to the LOQ.2.7.Data evaluationTo ensure the quality of the analysis when processing real-world samples,blank samples fortiﬁed at the LOQ and10×LOQ concentration levels(50and500ng/L for waters,and 0.05and0.5mg/kg for soils)were used as quality controls (QC)distributed along the batch of samples every three-four injections.The quantiﬁcation of the sample batch was con-sidered satisfactory if the QC recoveries were in the range of 70–120%.The values found in real samples were conﬁrmed by means of the two transitions selected for each compound. In this way,quantiﬁcation was carried out independently with each transition(see MS Optimisation),accepting a deviation of±20%in the concentrations obtained with both transi-tions.3.Results and discussion3.1.MS optimisationFull-scan MS spectra and product-ion MS/MS spectra of the FMOC derivatives of glyphosate,glufosinate and AMPA were recorded in both positive and negative ionisation modes.M.Ib´a ˜n ez et al./J.Chromatogr.A 1081(2005)145–155149Fig.2.The positive ion electrospray full scan mass spectrum (top)and product ion spectra (bottom)of (a)AMPA-FMOC,(b)glyphosate-FMOC and (c)glufosinate-FMOC,obtained from the chromatographic peak of 10mg/L standard solution of each compound,previously derivatizated.Spectra were obtained from the chromatographic peak of 10mg/L standard solution of each compound,previously derivatized.Although these compounds have been traditionally recorded in negative ion mode [9,10],in our work the sensi-tivity in positive ion mode was found to be approximately two times higher.Moreover,the product ions observed in negative ion mode were due to neutral unspeciﬁc losses of FMOC,or FMOC plus water.Thus,any isobaric compound that could have been derivatized with FMOC and also presented a water loss,would show the same product ions in its MS/MS spec-tra,being therefore not very selective.For all these reasons,positive ion mode was selected.The positive-ion electrospray full scan spectrum of AMPA-FMOC at a cone of 30V showed a base peak at m /z 334corresponding to the protonated derivatized molecule [M +H]+.The MS/MS spectra showed three abundant frag-ments at m /z 179,156and 112(Fig.2a).As can be seen in Fig.3a,fragments at m /z 179,m /z 156(M-178)and m /z 112(M-222)would appear in any isobaric amine that could have been derivatized with FMOC.As there were not signiﬁcant differences in the selectivity of these transitions,the criterium applied for their selection was the sensitivity,choosing the two most sensitive ones.The positive-ion electrospray full scan spectrum of glyphosate-FMOC at a cone of 30V showed a peak at m /z 392corresponding to the protonated derivatized molecule [M +H]+.The MS/MS spectra showed abundant fragments at m /z 214,179,170and 88(Fig.2b).The fragments at m /z 179and the fragments at m /z 214(M-178)and m /z 170(M-222)would appear in any isobaric amine that could have been derivatized with FMOC (Fig.3a).Thus,the selected reac-tion monitoring (SRM)transitions chosen were 392→88for quantiﬁcation as the most selective (see Fig.3b)andTable 1Optimised MS/MS parameters for the FMOC derivatives of glyphosate,AMPA,glufosinate and internal standard,selected for the residue analysis of water and soil Compound Cone voltage (V)Precursor ion (m /z )Product ion (m /z )a Collision energy (eV)Glyphosate-FMOC 30392.0Q 88.120q 214.110Glufosinate-FMOC 30404.0Q 136.125q 208.210AMPA-FMOC30334.0Q 179.120q 112.115Isotope-labeled glyphosate-FMOC30395.0Q 91.120q 217.110aQ ,Transition used for quantiﬁcation;q :transition used for conﬁrmation.150M.Ib´a ˜n ez et al./J.Chromatogr.A 1081(2005)145–155Fig.3.(a)Common fragmentation pathway for the three derivatised compounds;(b)speciﬁc fragmentation pathway for glyphosate and glufosinate.392→214for conﬁrmation as it was the most sensitiveamong the less selective.In the case of glufosinate,the positive-ion electrospray full scan spectrum showed a peak at m /z 404corresponding to the protonated molecule of glufosinate-FMOC.The MS/MS spectrum showed four abundant fragments at m /z 208,182(M-222),179and m /z 136(Fig.2c).We choose the most selective transitions:404→208and 404→136(see Fig.3b)despite their lower sensitivity.The selected reaction monitoring (SRM)transitions cho-sen for the residue determination of the three compounds,as well as the optimised MS/MS parameters,are shown in Table 1.3.2.Method optimisationFirstly,several attempts were carried out in order to deter-mine these compounds directly,i.e.without any previousM.Ib´a˜n ez et al./J.Chromatogr.A1081(2005)145–155151derivatization.For this purpose we checked Hydrophilic Interaction Chromatography using an Atlantis TM HILIC 5␮m Silica Column(100mm×2.1mm i.d.,Waters).This column offers superior retention for very polar compounds that are not well retained under reversed-phase conditions. Although the retention obtained with this column at acidic pH was satisfactory,we observed poor sensitivity,making necessary a preconcentration step.We did not try to perform such a preconcentration because this step is difﬁcult for sub-ppb levels of glyphosate and forces one to a higher sample manipulation.Additionally,the conditions to obtain satisfac-tory retention and peak shape were very speciﬁc and changed drastically when changing either pH of the sample or modiﬁer concentration in the mobile phase,decreasing the robustness of the method.For these reasons,a derivatisation procedure was carried out in order to increase the retention of analytes in the most common RPLC cartridges and to work under no so strict conditions.Derivatization procedures with FMOC-Cl have already been reported in the literature[9–15].Due to the low sol-ubility and stability of FMOC-Cl in water,this reagent is usually prepared in acetonitrile.Normally the high con-centration of FMOC required for the derivatization,makes that the derivatized sample presents a high percentage of acetonitrile.Thus,a dilution step with water is necessary to reduce the organic percentage[14],with the subse-quent loss of sensitivity,to retain glyphosate,glufosinate and AMPA in the cartridge due to the high polar charac-ter of these compounds,even derivatized.In this paper,we decreased the volume of the FMOC solution used but increas-ing its concentration and also the volume of water sample derivatized with the aim of minimizing the dilution factor. The effect of adding different FMOC concentrations with different reaction times was studied.The best results for both,water and soil samples,were obtained after perform-ing the reaction overnight with a FMOC concentration of 12,000mg/L.On the other hand,as the borate solution could not buffer properly the alkaline sample extract,a neutralizing step was necessary before the derivatization.Any attempt ofﬁxing the volume of HCl necessary to neutralize the KOH excess failed due to the different nature of the soils.Therefore,this step was done manually adding drops of HCl6M and0.6M until pH around7.Once the derivatization reaction took place overnight, hydrochloric acid was added to stop the reaction,by low-ering the pH.In soil samples,after direct injection of50␮L of the derivatized acidiﬁed extract,recoveries around25%with RSD up to80%were obtained for the three analytes,showing a severe matrix effect in both the MS instrument and/or the derivatization procedure.Among the solutions described to solve this problem(see Section1),the increase of the sample treatment was not considered as the best strategy for monitor-ing programs where rapid methods are preferred.Moreover, the use of matrix-matched standards calibration is not a robust approach when environmental samples are analysed,due to their different origin and composition,making the selection of a blank matrix difﬁcult.Thus,the use of internal stan-dards(IS)was tested,but only isotope-labelled glyphosate was commercially available.As expected,the use of this IS improved accuracy and pre-cision for glyphosate as it compensated the matrix effects,due to the similar chemical behaviour of analyte and IS.However, still ionization inhibition occurred lowering the sensitivity of the overall analytical procedure.In the case of AMPA and glufosinate,although better recoveries were obtained(around 116–127%),the RSDs were still unacceptable(higher than 15%).Therefore,the dilution of soil extracts with LC grade water was assayed as a fast and simple way to minimize matrix interferences.Thus,ﬁve soil samples of different origins were fortiﬁed at the0.5mg/kg and their extracts derivatized and,10-fold and20-fold diluted with water.According to our results(see Table2),10-and20-fold dilution would be adequate for accurate quantiﬁcation,even without internal standard.However,the use of internal standard improved the RSDs,especially for glyphosate.In the case of glufosinate, quantiﬁcation with labelled glyphosate IS did not improve the results.A similar situation has been previously reported in literature,when using analogues IS,demonstrating the dif-ﬁculty of selecting an adequate IS when the labelled analyte is not available[28].Finally,glyphosate and AMPA were quantiﬁed using internal standard meanwhile glufosinate was quantiﬁed with external standard calibration.A10-fold dilu-tion of the extract was chosen as it led to the best LODs.In regard to water samples,after injection of4.3mL of the derivatized sample into the SPE–LC–MS/MS,recoveriesTable2Effect of dilution of soil extracts previously to the derivatization step on the recovery and reproducibility of the method(n=5)a Compound Without dilution10-Fold dilution20-Fold dilution%Recovery b (%RSD)%Recovery c(%RSD)%Recovery b(%RSD)%Recovery c(%RSD)%Recovery b(%RSD)%Recovery c(%RSD)Glyphosate25(79)97(6)83(24)98(3)83(23)91(11) AMPA28(46)127(27)87(9)98(11)89(8)98(10) Glufosinate27(56)116(18)94(8)118(19)92(8)107(9)a Five different soil samples,spiked at0.5mg/kg each.b Quantiﬁcation without internal standard.c Quantiﬁcation with internal standard.。

chemical science排序

chemical science排序Chemical ScienceChemical science is a branch of science that focuses on the study of chemicals, their properties, and their interactions. It plays a crucial role in various aspects of our daily lives, from the development of new materials to the understanding of biological processes. In this article, we will explore different areas of chemical science and their significance.1. Inorganic Chemistry:Inorganic chemistry deals with the study of inorganic compounds, which include minerals, metals, and nonmetals. It focuses on understanding their structures, properties, and reactions. Inorganic chemistry plays a vital role in various industries, such as pharmaceuticals, materials science, and environmental science. For example, in the field of catalysis, inorganic chemists develop catalysts that can enhance chemical reactions and increase efficiency.2. Organic Chemistry:Organic chemistry is the study of carbon compounds and their reactions. It is a vast field that encompasses thestudy of organic molecules, such as hydrocarbons, polymers, and bioactive compounds. Organic chemists contribute to the development of pharmaceuticals, agrochemicals, and materials. They design and synthesize new molecules with desired properties, such as drugs that can treat diseases or materials with specific functions.3. Physical Chemistry:Physical chemistry focuses on the study of the physical and chemical properties of matter and the changes it undergoes during chemical reactions. It combines principles from physics and chemistry to understand the behavior of atoms, molecules, and solids. Physical chemists use mathematical models and computational methods to predict and explain experimental observations. This field is essential for understanding reaction mechanisms, energy transfer, and the design of new materials.4. Analytical Chemistry:Analytical chemistry involves the development and application of methods to determine the composition, structure, and quantity of substances. It plays a significant role in quality control, environmentalmonitoring, and forensic analysis. Analytical chemists use various techniques, such as spectroscopy, chromatography, and electrochemistry, to analyze samples and obtain accurate measurements. Their work ensures the safety and reliability of products and helps in identifying unknown substances.5. Biochemistry:Biochemistry is the study of the chemical processes and substances that occur within living organisms. It focuses on understanding biological molecules, such as proteins, carbohydrates, and nucleic acids, and their functions in cells. Biochemists investigate enzyme kinetics, metabolic pathways, and the structure of biomolecules. Their research is crucial for understanding diseases, developing new drugs, and designing biotechnological processes.6. Materials Chemistry:Materials chemistry involves the design, synthesis, and characterization of new materials with desired properties. It combines principles from chemistry, physics, and engineering to develop materials for various applications. Materials chemists work on developing materials withimproved conductivity, strength, or optical properties. They contribute to the advancement of technologies such as solar cells, batteries, and electronic devices.7. Environmental Chemistry:Environmental chemistry focuses on the study of chemical processes in the environment and their impact on ecosystems and human health. It involves the analysis of pollutants, the study of chemical reactions in the atmosphere, and the development of methods to remediate contaminated sites. Environmental chemists work on understanding the fate and transport of pollutants and develop strategies to mitigate their effects.In conclusion, chemical science encompasses various sub-disciplines that contribute to our understanding of the world around us. From the development of new materials to the study of biological processes, chemical science plays a vital role in advancing technology, improving healthcare, and protecting the environment. The continuous exploration and application of chemical principles are essential for addressing the challenges of the modern world.。

化学化工专业资料库简介S

10
= integer +
10
N:The digits of the CAS Registry Number from right to left,excluding the check.
R:Check number
Example:7732-18-5
6* 7+5* 7+4* 3+3* 2+2* 1+1* 8
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新用戶購買 V5.0(單機版)，費用為US$195。舊用戶由V4.1升級為V5.0，費用為US$49。
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Title Author Source Abstract Indexing Terms 全文式資料 Title Author Full-Text Source Abstract Document Text 化學物質目錄式資料 Structures Chemical Substance Chemical Names Molecular Formulas 數據式資料 Numeric Physical and Chemical Numeric Property Data
化學物質登錄號(CAS RN)系統
登錄號就好像化合物有了身份証字號一樣的方便，不像命名一樣複雜。
如一般IUPAC命名的4,4’-sulfonyldianiline為例、它的商品名為Avlosulfon、它的實驗名為NSC 6091、進而CA索引命名為Benzenamine,4,4’-sulfonyl bis- 、至於其它的命名又如：1,1’-sulfonylbis﹝4-aminobenzene﹞等其化學物質登錄號為【80-08-0】而CAS RN不僅只使用在由CAS出版的書籍，其它的資料庫或出版品也採用CAS RN，如此一來，對查詢化學物質而言，實在是方便許多。目前進出口海關化學物品時，也會要求要具備化學物質登錄號的資料。

应用地球化学元素丰度数据手册-原版

应用地球化学元素丰度数据手册迟清华鄢明才编著地质出版社·北京·1内容提要本书汇编了国内外不同研究者提出的火成岩、沉积岩、变质岩、土壤、水系沉积物、泛滥平原沉积物、浅海沉积物和大陆地壳的化学组成与元素丰度，同时列出了勘查地球化学和环境地球化学研究中常用的中国主要地球化学标准物质的标准值，所提供内容均为地球化学工作者所必须了解的各种重要地质介质的地球化学基础数据。

本书供从事地球化学、岩石学、勘查地球化学、生态环境与农业地球化学、地质样品分析测试、矿产勘查、基础地质等领域的研究者阅读，也可供地球科学其它领域的研究者使用。

图书在版编目（CIP）数据应用地球化学元素丰度数据手册/迟清华，鄢明才编著. －北京：地质出版社，2007.12ISBN 978－7－116－05536－0Ⅰ. 应… Ⅱ. ①迟…②鄢…Ⅲ. 地球化学丰度－化学元素－数据－手册Ⅳ. P595－62中国版本图书馆CIP数据核字（2007）第185917号责任编辑：王永奉陈军中责任校对：李玫出版发行：地质出版社社址邮编：北京市海淀区学院路31号，100083电话：（010）82324508（邮购部）网址：电子邮箱：zbs@传真：（010）82310759印刷：北京地大彩印厂开本：889mm×1194mm 1/16印张：10.25字数：260千字印数：1－3000册版次：2007年12月北京第1版•第1次印刷定价：28.00元书号：ISBN 978－7－116－05536－0（如对本书有建议或意见，敬请致电本社；如本社有印装问题，本社负责调换）2关于应用地球化学元素丰度数据手册（代序）地球化学元素丰度数据，即地壳五个圈内多种元素在各种介质、各种尺度内含量的统计数据。

它是应用地球化学研究解决资源与环境问题上重要的资料。

将这些数据资料汇编在一起将使研究人员节省不少查找文献的劳动与时间。

这本小册子就是按照这样的想法编汇的。

昆虫与植物的协同进化_寄主植物_铃夜蛾_寄生蜂相互作用

科技前沿昆虫与植物的协同进化:寄主植物-铃夜蛾-寄生蜂相互作用3王琛柱33　钦俊德(中国科学院动物研究所农业虫害鼠害综合治理研究国家重点实验室　北京　100080)I nsect 2plant co 2evolution :multitrophic interactions concerning Helicoverpa species .W ANG Chen 2Zhu 33,QI NJun 2De (State K ey Laboratory o f Integrated Management o f Pest Insects and Rodents ,Institute o f Zoology ,Chinese Academy o f Sciences ,Beijing 100080,China )Abstract In the field of insect 2plant interactions ,the theory of co 2ev olution proposed by Ehrlich and Raven in 1964and the theory of sequential ev olution by Jermy in 1976have stimulated many studies over recent decades.C oncerning the tw o theories ,several major questions are brought forward :(1)H ow insect herbiv ores select host plants ?(2)D o secondary com pounds protect plants from attacking of insect herbiv ores ?(3)D o insect herbiv ores adapt to plant chemical defenses ?(4)What pattern is the ev olution of host range in insect herbiv ores ,specialization or generalization?F ocused on the above questions ,the results in the studies of tritrophic interactions concerning Helicoverpa species were discussed.Based on the co 2ev olution and sequential ev olution theories and the considerableadvances made in tritrophic interactions recently ,a new hypothesis called multitrophic co 2ev olution is proposed.The multitropic co 2ev olution hypothesis accepts that plant secondary com pounds play an im portant role in chemical defense of plants and host selection of insect herbiv ores ,but expands the interacting insect 2plant system to the multitrophic system ,in which the im pact of the third trophic level and host shift on the ev olution of insect host range are em phasized.K ey w ords co 2ev olution ,sequential ev olution ,Helicoverpa ,multitrophic co 2ev olution hypothesis摘　要　近数10年内,Ehrlich 和Raven 于1964年提出的协同进化理论及Jermy 于1976年提出的顺序进化理论极大地促进了对昆虫与植物相互作用的研究。

Chemical Calculations

Chemical CalculationsMolecular mass : The sum of the atomic masses of all the atoms in a molecule of a substance.Formula mass : The sum of the atomic masses of all the atoms in a formula unit of a substance.For molecules: Molecular weight and formula weight are the same. For ionic compounds: Only the term formula weight applies.Mole: (mol)One mole of a substance is the quantity of that substance that contains as many elemental entities as the number of atoms in exactly 12.000 g of Carbon-12. That number is called Avogadro’s number (N A ). It is numerically equal to 6.022×1023. A mole is just a counting number like a dozen or a ream or a pair. When talking about a mole of something you must specify the formula unit of what you are using. 1 mol O is 6.022×1023 atoms of oxygen. 1 mol O 2 is 12.044×1023 atoms of oxygen.Molar Mass : The mass of one mole of substance.The molar mass in g/mol is numerically equivalent to the molecular or formula mass in amu.Examples:1. How many formula units are in 254.2 g of Lead(II) Oxide?The formula for Lead(II) Oxide is PbO which results in a molar mass of 223.19 g (207.19 g + 15.9994 g).PbO units formula 10859.6PbOmol 1PbO units formula 10022.6PbO g 19.223PbO mol 1PbO g 2.2542323×=×××2. 3.42×1022 molecules of water has what mass in grams ?Water has the formula H 2O so it has a molar mass of 18.0153 g (2×1.0079 g + 15.9994 g).O H g 02.1OH mole 1O H g 0153.18O H molecules 10022.6O H mole 1O H molecules 1042.32222232222=××××Chemical Equations and Stoichiometry Chemical EquationsA chemical equation is a shorthand way of indicating what is going on in a chemical reaction. We could do it the long way…Two molecules of Hydrogen gas react with one molecule of Oxygen gas to produce two molecule of liquid water.Or we can use the shorthand…2 H2 (g) + O2 (g) → 2 H2O (l)The second way is easier to read and keep track of everything going on. The equation above uses phase symbols. Phase symbols are used to denote the phase of substances in an equation.(g) gas(s) solid(l) liquid(aq)aqueous (water solution)The chemical equation must represent reality. The symbol, ∆, is sometimes used to denote a reaction that is heated and is written above the arrow. Catalyst symbols or formulas are also placed above the arrow.Balancing equationsAn equation is balanced when the number of atoms of each type present is the same on both sides of the equation. The chemical formulas CANNOT be changed in the process of balancing an equation. The process of balancing an equation can sometimes seem to be trial and error. In reality, there is a method to the madness. When we balance a chemical equation we are looking at the relationships between the elements on both sides of the equation. This relationship helps us to figure out what needs to be done. Some basic rules for balancing chemical equations are…1. Start with the most complicated chemical first and start with the element thatappears the most number of times in that compound.2. Save “free” elements for last.Example:CH4 (g) + O2 (g) → CO2 (g) + H2O (l)Here CH 4 is the most complicated and Hydrogen appears the most number of times so we will start with that element. O 2 is a “free” element (not combined with other elements) so we will leave that for last.There are 4 Hydrogens on the reactant side and 2 on the product side. Therefore, we multiply the water on the product side by 2 and the hydrogens balance.CH 4 (g ) + O 2 (g ) → CO 2 (g ) + 2 H 2O (l )The carbons are already balanced. Now we can balance the oxygen atoms. There are 2 on the reactant side and 4 on the product side. If we multiply the O 2 by 2 we balance the oxygen.CH 4 (g ) + 2 O 2 (g ) → CO 2 (g ) + 2 H 2O (l )Now the equation is balanced.Molar interpretation vs. Molecular interpretation of a chemical reactionThe balanced chemical reaction gives you a series of conversion factors to use in problem solving.CH 4 + 2 O 2 → CO 2 + 2 H 2OThe conversion factors are obtained from the coefficients in the balanced chemicalreaction. These conversion factors can be used to relate the amounts of reactant to other reactants or to amounts of products. It is this reason that, in order to solve a chemical problem, you first need to have a balanced chemical equation.Example:How many grams of solid Barium Sulfate can be produced from thereaction of 154.6 g of Barium Nitrate with Sodium Sulfate? The otherproduct of the reaction is Sodium Nitrate.First we need to write the balanced chemical equation:Ba(NO 3)2 + Na 2SO 4 → BaSO 4 + 2 NaNO 3Now we can proceed with the calculation.444234232323BaSO g 1.138BaSO mol 1BaSO g 233.391)Ba(NO mol 1BaSO mol 1)Ba(NO g 261.337)Ba(NO mol 1)Ba(NO g 6.154=×××。

Green Chemistry_四川大学中国大学mooc课后章节答案期末考试题库2023年

Green Chemistry_四川大学中国大学mooc课后章节答案期末考试题库2023年1.One of the obvious effect of catalysis to facilitate the reaction is to minimizethe activation energy (energy costs), and thus reduce the reactiontemperature.参考答案:正确2.Principles for designing safer dye chemicals to aquatic species include:参考答案:Sulfonic group (磺酸基) is better than carboxylic group (羧酸基)_Molecular weight should be larger than 1000 Daltons3.If we compare the molecule A (【图片】) with another molecule B (【图片】), the molecule A shows higher toxicity than the molecule B.参考答案:错误4.In some cases, the application of atomic economical reaction in chemicalsynthesis is not enough for eliminating the formation of wastes. These cases include:参考答案:Low product stereoselectivity_The presence of parallel reaction_Lowequilibrium conversion5.Muscarinic antagonistis (蝇覃碱拮抗剂)【图片】is a silane analog ofneopentyl carbamate (新戊基氨基甲酸酯)【图片】, the former is morebiodegradable than the latter.正确6.The use of catalysts is preferred in green chemistry because of the followingreasons:参考答案:Reduce environmental pollutions_Activate new startingmaterials_Increase the selectivity of a special product_Promote thechemical processes7.For delocalized cationic dyes containing N, the toxicity comparison should be:参考答案:The more substituents on N atom there are, the more acute the toxicity is_Primary N < Secondary N < Tertiary N8.Biodegradability of chemicals is usually enhanced by the following molecularfeatures:参考答案:Oxygen in the form of hydroxyl or carboxylic groups_Un-substitutedlinear alkyl and phenyl rings9.The eventual mineralization of organic compounds can be attributedpredominantly to the biodegradation by higher organisms.参考答案:错误10.Considering the food requirement, the following biomass resources could beused as the chemical feedstocks for producing fine chemicals and liquid fuels:Microalgae_Woody wastes11.These renewable feed-stocks are most often associated with biological andplant based starting materials, including:参考答案:Saw dust_Agricultural wastes12.Catalytic distillation is a kind of technique of process intensification, whichcombines the catalytic reaction and product separation in a single distillation column. Which equipment or techniques in the following are included inprocess intensification?参考答案:Microreactors_Static Mixers_Membrane reactor13.Oxidation reactions are frequently used in petrol-refinery (石油炼制). Tominimize the pollutions induced by inorganic oxidants, some green oxidants could be used in chemical synthesis. These green oxidants include:参考答案:O3_lattice oxygen_N2O14.Which typical environmental problems in the following are related tochemical industry?参考答案:Global warming_Acid rain_Depletion of ozone layer_Photochemicalsmog and haze15.Chemical reaction with 100% atom utilization has two characteristics. Thereactants could be fully utilized, and the resource could be most possiblyused economically. The waste could be minimized.参考答案:正确16.We can use the following substances to replace the traditional inorganicoxidants such as CrO3, KMnO4, and HNO3 in cleaner oxidation reactions:参考答案:H2O2_O2_N2O_Lattice oxygen17.We can control the reaction process even we cannot measure the parametersof chemical reaction.参考答案:错误18.The atomic economical reaction is not a requisite condition (必要条件) foreliminating the formation of wastes because the low equilibrium conversion and low product selectivity in a chemical reaction will also bring aboutpollutions.参考答案:错误19.The goal of green chemistry is to treat the environmental pollutions alreadygenerated in chemical reactions.参考答案:错误20.Renewable feedstocks are the substances that are easily regenerated withintime frames that are accessible to the human lifetime, including carbondioxide and methane.参考答案:正确21.The goal of green chemistry is to eliminate the potential of pollution before itoccurs.参考答案:正确22.Volatile organic compounds (VOCs) are frequently used as solvents inchemical reactions, which will lead to potential harmfulness to handlers and environments. From the viewpoints of green chemistry, which in thefollowing could be used as new solvents instead of VOCs for chemicalsynthesis?参考答案:Supercritical CO2_Deep eutectics (低共熔溶剂)_Water23.The following molecular features of chemicals generally do increase theresistance to aerobic(需氧) biodegradation, except:参考答案:Potential sites of enzymatic hydrolysis_Un-substituted linear alkylchains24.The possible effects of the solubility of chemicals on biodegradability are asfollows:参考答案:Microbial bioavailability_Rate of solubilization25.Which group of metals in the following should we avoid using when we aredesigning metalized acid dyes (金属化酸性染料).参考答案:Al, Cr, or Zn_Al, Cr, or Co_Cr, Co, or Zn26.If O has been inserted into the structure during molecular design, thebiodegradability of a chemical will be enhanced.参考答案:正确27.DDD【图片】is a silane analog of DDT 【图片】(organochlorine pesticide 有机氯杀虫剂), the former is more biodegradable than the latter.参考答案:正确28.The reaction types involved in biomass conversion to fine chemicals andliquid fuels include:参考答案:Hydrolysis_Deoxygenation_Hydrogenation29.One of the research area in Green Chemistry is to use renewable feedstocksfor chemical production. Which could be used as feedstocks for chemicalproduction in the following resources?参考答案:Microalgae_Agricultural wastes_Kitchen garbage_Waste cooking oil30.Traditional pollution treatment can provide a permanent cure.参考答案:错误31.Classification of surfactants includes:参考答案:Anionic surfactants_Cationic surfactants_Amphotericsurfactants_Neutral surfactants32.The majority of chemicals that are toxic to aquatic species are toxic byspecific toxicity.参考答案:错误33.For very insoluble chemicals, the replacement of a given functional groupthat increases solubility may reduce the biodegradability.参考答案:错误34.The introduction of O is particularly important for biodegradation, becausethe 1st step of biodegradation is some kind of oxidation reaction which is almost always the rate limiting step.参考答案:正确35.Several unconventional processing techniques that rely on alternative formsand sources of energy are of importance for process intensification. These alternative forms and sources of energy include:参考答案:Solar energy_Photo and other radiation_Sonic_Microwaves36.The energy is widely used in chemistry and chemical industry in thefollowing aspects:参考答案:Separation energy requirement_Accelerates the reaction rate withheat_The need to control reactivity through cooling_Pre-heating of the reaction mixture。

世界各种组织会议中英文名大全

欧洲联盟（欧盟）独立国家联合体（独联体）上海合作组织阿拉伯各国议会联盟阿拉伯国家联盟（阿盟)西欧联盟拉丁美洲议会阿拉伯马格里布联盟非洲联盟（非盟）欧洲安全与合作组织（欧安组织)美洲国家组织法语国家组织（又称“法语共同体”）里约集团国际移民组织伊比利亚美洲国家首脑会议桑戈委员会亚洲议会和平协会禁止化学武器组织欧洲委员会南亚区域合作联盟（南盟)波罗的海国家委员会非洲统一组织（非统组织)各国议会联盟（议联)维谢格拉德集团政府间移民委员会巴黎统筹委员会（巴统）的正式名字是“输出管制统筹委员会” 亚太议会论坛海湾合作委员会（海合会)联合国协会世界联合会 (世联会)大赦国际国际刑事警察组织（国际刑警组织)伊斯兰会议组织前政府首脑国际行动理事会英联邦国际刑事法院加勒比国家联盟南美洲国家联盟前身为南美国家共同体（南共体)社会党国际核供应国集团葡萄牙语国家共同体（葡语国家共同体)“中欧倡议国”组织不结盟运动澳新美理事会自由进步党国际古阿姆民主与发展组织巴黎俱乐部也称“十国集团”７７国集团国际劳工组织中国－阿拉伯国家合作论坛地中海联盟美洲议会联盟萨赫勒－撒哈拉国家共同体（简称萨－撒共同体）南方中心金砖四国中美洲议会美洲玻利瓦尔联盟世界贸易组织（世贸组织）亚太经济合作组织（亚太经合组织）石油输出国组织东非政府间发展组织 (伊加特）经济合作与发展组织亚洲开发银行 (亚行）世界银行集团，俗称世界银行阿拉伯石油输出国组织“十五国集团”又称“南南磋商与合作首脑级集团” 非洲开发银行欧洲复兴开发银行（欧洲银行）环印度洋地区合作联盟二十国集团美洲开发银行加勒比开发银行中部非洲国家经济共同体２４国集团欧洲中央银行欧洲自由贸易联盟南部非洲发展共同体国际展览局南方共同市场（南共市）比荷卢经济联盟西非经济共同体关税及贸易总协定 (关贸总协定)安第斯共同体 (安共体)太平洋岛国论坛大湖国家经济共同体博鳌亚洲论坛太平洋共同体东部和南部非洲共同市场（东南非共同市场）非洲发展新伙伴计划世界旅游组织东非共同体西非经济货币联盟 (西非经货联盟)加勒比共同体和共同市场国际能源机构拉美经济体系中美洲一体化体系大湄公河次区域经济合作世界能源理事会拉丁美洲一体化协会国际航空运输协会非洲、加勒比和太平洋地区国家集团（非加太集团）黑海经合组织发展中八国集团（伊斯兰发展中八国集团）反洗钱金融行动特别工作组国际货币基金组织南方银行加勒比石油计划国际标准化组织泛美开发银行集团科技、文化世界卫生组织 (世卫组织)第三世界科学院世界民主青年联盟国际足球联合会国际科学理事会世界基督教会联合会亚洲奥林匹克理事会国际档案理事会国际自由工会联合会国际奥林匹克委员会世界文化和自然遗产政府间委员会（世界遗产委员会）国际交流发展计划万国邮政联盟国际军事体育理事会世界汉语教学学会世界盲人联盟国际音乐理事会国际信息处理联合会世界厕所组织（也简称WTO）国际世界语协会(国际世协）国际新闻工作者协会国际新闻学会国际战略研究所国际新闻工作者联合会国际大学协会国际奥比斯组织国际图书馆协会联合会（国际图联）世界穆斯林大会无国界医生组织国际翻译家联盟 (国际译联)世界土著人理事会国际新闻电影协会国际自然及自然资源保护联盟世界佛教徒联谊会世界科技城市联盟国际志愿服务协调委员会国际会计师联合会世界休闲组织国际红十字会与红新月会联合会亚太空间合作组织世界医护人员联盟国际反贪局联合会国际捕鲸委员会世界知识产权组织世界动物卫生组织非洲性别平等集团世界气象组织国际博物馆协会世界移动通信大会和全球移动通信系统协会国际人类学与民族学联合会世界技能组织亚欧会议亚洲相互协作与信任措施会议（亚信会议）东亚峰会国际反贪污大会世界经济论坛世界社会论坛世界经济论坛世界社会论坛世界卫生大会世界妇女大会世界华商大会世界石油大会世界青年大会法非首脑会议日内瓦裁军谈判会议 (裁谈会)东盟外长会议上海合作组织峰会世界粮食首脑会议二十国集团峰会世界大城市首脑会议巴尔干国家首脑会议非洲－欧洲首脑会议联合国小岛屿国家会议联合国千年首脑会议联合国反对种族主义世界大会联合国国际人口与发展大会世界妇女峰会世界城市论坛亚洲政党国际会议东盟地区论坛世界水资源论坛世界月球会议世界知识论坛世界湖泊大会亚太经合组织领导人非正式会议东盟与中国（“１０＋１”）领导人会议东盟与中日韩（１０＋３）领导人会议东南欧稳定公约魏玛三角“北美安全与繁荣联盟”首脑会议（北美峰会）政治类组织European Union -- EUCommonwealth of Independent States -- CISShanghai Cooperation Organization -- SCOArab Inter-Parliamentary Union -- AIPULeague of Arab States -- LASWestern European Union -- WEULatin-American ParliamentUnion of the Arab Maghreb；Union du Maghreb Arabe -- UMA African Union -- AUOrganization for Security and Co-operation in Europe -- OSCE Organization of American States -- OASOrganisation Internationale de la Francophoniethe Rio GroupInternational Organization for Migration -- IOMIbero-American SummitZangger Committee -- ZACThe Association of Asian Parliaments for Peace—AAPP Organization for the Prohibition of Chemical Weapons -- OPCW Council of Europe -- COESouth Asian Association for Regional Cooperation -- SAARC Council of the Baltic Sea States -- CBSSOrganization of African Unity -- OAUInter-Parliamentary Union -- IPUVisegrad GroupIntergovernmental Committee for Migration -- ICMCo-Ordinating Committee for Export ControlThe Asia-Pacific Parliamentary Forum — APPFGulf Cooperation Council -- GCCWorld Federation of United Nations Association -- WFUNA Amnesty International -- AIInternational Criminal Police Organization -- TERPOL Organization of the Islamic Conference -- OICInter Action Council of Former Heads of Government -- ICFHG The CommonwealthInternational Criminal Court -- ICCAssociation of Caribbean States -- ACSSouth American Community of Nations — CSNSocialist International -- SINuclear Suppliers Group -- NSGCommunity of Portuguese-Speaking Countries -- CPLPCentral European Initiative -- CEINon-Aligned Movement -- NAMANZUS councilLiberal International -- LIGUAM Organization for Democracy and Economic DevelopmentParis Club (Group-10)Group of 77 -- G77International Labor Organization -- ILOChina-Arab Cooperation ForumMediterranean UnionAmerican Parliamentary UnionCommunity of Sahel - Saharan StatesSouth CentreＢＲＩＣｓCentral American ParliamentBolivarian alliance经济类组织World Trade Organization -- WTOAsia-Pacific Economic Cooperation -- APECOrganization of Petroleum Exporting Countries -- OPECIntergovernmental Authority on Development -- IGADOrganization for Economic Cooperation and Development -- OECDAsian Development Bank -- ADBWorld BankOrganization of Arab Petroleum Exporting Countries -- OAPECGroup 15（Summit Level Group for South-South Consultation and Cooperation）African Development Bank -- ADBEuropean Bank for Reconstruction and Development -- EBRDIndian Ocean Rim Association for Regional Cooperation -- IOR-ARCGroup of TwentyInter-American Development Bank -- IDBCaribbean Development Bank -- CDBEconomic Community of Central African States -- ECCASGroup of Twenty Four -- G2European Central Bank -- ECBEuropean Free Trade Association -- EFTASouthern African Development Community -- SADCBureau of International Expositions -- BIESouth American Common Market-- MERCOSURUnion Economique BeneluxEconomic Community of West African States --ECOWASGeneral Agreement on Tariffs and Trade -- GATTAndean CommunityPacific Islands ForumEconomic Community of the Great Lakes CountriesBoao Forum for Asia -- BFAPacific Community -- PCCommon Market for Eastern and Southern Africa -- COMESAthe New Partnership for Africa's Development -- NEPADWorld Tourism OrganizationEast African Community -- EACUnion Economique et Monétaire Ouest-Africaine -- UEMOACaribbean Community and Common Market -- CARICOMInternational Energy Agency -- IEALatin Aamerican Economic System -- LAESCentral American Integration System -- SICAGreater Mekong Subregion Economic CooperationWorld Energy Council -- WECLatin American Integration Association -- LAIAInternational Air Transport Association -- IATAGroup of African, Caribbean and Pacific Region Countries -- Group of the ACP Bangladesh Steel & Engineering Corporation--BSECthe Group of the developing G8 (Group of Eight Islamic Developing)Financial Action Task Force on Money Laundering -- FATFInternational Monetary Fund -- IMFSouth BankCaribbean oil planInternational Organization for Standardization--ISOInter-American Development Bank Group、文化、体育等专业类组织World Health Organization -- WHOThird World Academy of Sciences -- TWASWorld Federation of Democratic Youth -- WFDYFederation Internationale de Football Association -- FIFAInternational Council for Science -- ICSUWorld Council of Churches -- WCCOlympic Council of Asia -- OCAInternational Council on Archives -- ICAInternational Confederation of Free Trade Unions -- ICFTUInternational Olympic Committee -- IOCWorld Heritage CommitteeInternational Programme for the Development of Communication — IPDCUniversal Postal Union -- UPUInternational Military Sports Council -- CISMInternational Society for Chinese Language TeachingWorld Blind UnionInternational Music Council -- IMCInternational Federation for Information Processing -- IFIPWorld Toilet OrganizationUniversal Esperanto Association -- UEAInternational Organization of JournalistsInternational Press Institute -- IPIInternational Institute for Strategic Studies -- IISSInternational Federation of Journalists -- IFJInternational Association of Universities -- IAUProject Orbis -- ORBISInternational Federation of Library Associations and Institutions -- IFLAWorld Muslim Congress -- WMCDoctors Without Borders, Medecins Sans Frontiers -- MSFInternational Federation of Translators；Federation International des Traducteurs -- FIT World Council of Indigenous PeoplesInternational Newsreel and News Film Association -- INNAInternational Union for Conservation of Nature and Natural Resources -- IUCNWorld Fellowship of Buddhists -- WFBWorld Technoplis Association -- WTACoordinating Committee for International Voluntary Service -- CCIVSInternational Federation of Accountants -- IFACWorld Leisure OrganizationInternational Federation of Red Cross and Red Crescent SocietiesAsia-Pacific Space Cooperation Organization--APSCOWorld allience of heakth careInternational Association of Anti-Corruption Authorities --IAACAInternational Whaling CommissionWorld Intellectual Property Organization -- WIPOOffice International Des Epizooties --OIEAfrican Gender Equality GroupWorld Meteorological Organization -- WMOInternational Council of MuseumsMobile World Congress and Global System for Mobile Associationthe International Union of Anthropological and Ethnological Sciiences--ＩＵＡＥＳWorldSkills International国际会议Asia-Europe Meeting -- ASEMConference on Interaction and Confidence-Building Measures in Asia -- CICAEast Asia SummitInternational Anti-Corruption Conference -- IACCWorld Economic Forum -- WEFWorld Social Forum — WSFWorld Economic Forum -- WEFWorld Social Forum — WSFWorld Health Assembly -- WHAWorld Conference on WomenWorld Chinese Entrepreneurs Convention -- WCECWorld Petroleum Congress -- WPCWorld Assembly of Youth -- WAYFranco-African SummitConference on Disarmament in GenevaASEAN Foreign Ministers MeetingShanghai Cooperation Organization SummitWorld Food SummitSummit of the Group of TwentySummit Conference of Major Cities of the World -- SCMCWBalkan SummitAfrica-Europe SummitUnited Natiosn Global Conference on the Sustainable Development of Small Island Developing United Nations Millennium SummitWorld Conference Against Racism of United NationsInternational Conference on Population and DevelopmentGlobal summit of womenWorld Urban ForumInternational Conference of Asian Political PartiesASEAN Regional ForumWorld Water ForumGlobal summit of moonWorld Knowledge ForumWorld Lake ConferenceAPEC Informal Leadership MeetingASEAN-China High- level SymposiumASEAN, China, Japan and ROK （10 ＋ 3 ） High- level SymposiumStability Pact for South Eastern EuropeWeimar Triangle summitSecurity and Prosperity Partnership of North America --SPPurs -- FIT ＩＵＡＥＳd Developing States。

2-巯基苯并噻唑的合成与固体吸附剂对合成反应的影响

第38卷第3期河北工业大学学报2009年6月V ol.38No.3JOURNAL OF HEBEI UNIVERSITY OF TECHNOLOGY June2009文章编号：1007-2373(2009)03-0029-04Ïõ»ù±½»ìºÏ·¨´úÌæ´«Í³µÄ±½°··¨ºÏ³É2-巯基苯并噻唑（促进剂M），确定了最佳的合成条件：反应温度为240~260℃，反应时间为4h，产品收率大于80%．以活性氧化铝、二氧化硅和活性炭3种常见的固体吸附剂为催化剂，考察了固体吸附剂对合成反应的影响，催化效果明显：2-巯基苯并噻唑的收率由原来的80.6%提高到了85%以上，最高达到86.7%；反应时间由原来4h缩短为3h．关键词2-巯基苯并噻唑；促进剂M；合成；活性氧化铝；二氧化硅；活性炭中图分类号TQ251.2文献标识码ASynthesis of2-Mercaptobenzothiazole and Effects of SolidAdsorbents on the Synthetic ReactionHAN Jin-ping1，WANG Nong-yue2，FENG Xiao-gen2，PAN Ming-wang1(1.Institute of Polymer Science and Engineering,Hebei University of Technology,Tianjin300130,China; 2.Shanghai Sinorgchem(Group)Co.Ltd.,Shanghai200136,China)Abstract An improved process for the preparation of2-mercaptobenzothiazole(accelerator M)by reacting aniline,nit-robenzene,and carbon disulfide was disclosed.The reaction was optimal conducted at240℃to260℃for4hours withthe yield more than80percentage.Activated alumina,silica dioxide and activated carbon,which are three commonsolid adsorbents,were applied as catalyst,respectively.The yield of2-mercaptobenzothiazole was improved from theoriginal80.6%to more than85%,even up to86.7%.And the reaction time had been shortened from the original4hoursto3hours.Key words2-mercaptobenzothiazole;accelerator M;synthesis;activated alumina;silica dioxide;activated carbon2-巯基苯并噻唑在工业上简称促进剂M，它既是一种重要的硫化促进剂，是产量最大的促进剂品种，又是合成噻唑类和次磺酰胺类促进剂的中间体．2-巯基苯并噻唑的合成方法很多[1]，其中工业生产上比较成熟的合成路线是苯胺法．苯胺法是以苯胺、二硫化碳和硫磺为原料，在200~300℃，9.0~10.0MPa条件下反应，生成的粗品再经精制得到成品2-巯基苯并噻唑的方法[2-4]．Akzo等[5]发现某些酸、酸性物质或成酸物质可做催化剂．由于此法反应压力高，危险性大，反应后的副产物H2S又难以处理，因此寻找更可靠且废气排放量小的方法一直是助剂行业研讨的热门课题．苯胺法改进的硝基苯-苯胺混合法[6-8]是合成2-巯基苯并噻唑的一种新方法，也是近年来研究的热点．硝基苯与苯胺混合法不但成本低，而且副产物H2S的量比苯胺法降低1/3，但该法反应复杂、副产物多、产品纯度低，且对反应器的材料要求也较高．固体吸附剂是一些多孔、大比表面积、具有吸附活性的固体物质．本文采用硝基苯与苯胺混合法，以3种固体吸附剂活性氧化铝、二氧化硅和活性炭为催化剂合成2-巯基苯并噻唑，着重研究了它们对合成反应时间和产品收率的影响．1实验部分1.1主要原料与仪器设备原料：苯胺、硝基苯、二硫化碳（分析纯，国药集团化学试剂有限公司）；活性氧化铝、二氧化硅、收稿日期：2009-03-10作者简介：韩金平（1984-），女（汉族），硕士生；导师简介：潘明旺（1964-），男（汉族），教授．30河北工业大学学报第38卷活性炭（化学纯，天津市天大化工试验厂）；其他试剂均为国产化学纯．粉末活性氧化铝是孔体积为300~800mm 3/g 、比表面积为100~300m 2/g的ｍ、比表面积为200~400m 2/g ；活性炭比表面积为500~1000m 2/g （比表面积测试采用全自动F-Sorb2400比表面积分析仪，BET 法进行）．反应设备：GCF-1型高压釜（威海祥威化工机械厂生产）．1.2合成反应方程式2-巯基苯并噻唑合成的化学反应式如下主要副反应的反应式如下1.32-巯基苯并噻唑的合成与处理向高压釜中加入苯胺149.0g ，硝基苯98.5g ，二硫化碳292.4g 及适量吸附剂为催化剂，密闭，搅拌下加热升温，控制反应温度在设定温度范围内．待反应结束后，冷却降温，并用30%氢氧化钠溶液吸收反应产生的硫化氢气体，釜内固体物即为反应生成的粗产品2-巯基苯并噻唑．粗品2-巯基苯并噻唑经精制后得到成品．精制过程参照文献[8]方法进行，主要包括以下步骤：氢氧化钠碱液溶解、过滤、鼓风氧化、过滤、硫酸酸化、过滤、洗涤、真空干燥等．2结果与讨论2.1反应温度对产品收率的影响苯胺法合成2-巯基苯并噻唑的最低反应温度为200℃，最高温度为300℃[10]．参考上述反应温度，以确定本合成路线的最佳反应温度，实验过程如1.3所述，反应时间拟定为4h ．改变反应温度，考察不同反应温度对产品收率的影响，结果如图1所示．从图1可以看出：反应温度为240~260℃时，2-巯基苯并噻唑的收率较高，达到80%左右．从实验现象来看，反应温度越高，反应速度越快；温度越低，反应速度越慢．当反应温度过低时，反应速度较慢，副反应较多，生成的杂质较多，对产品的收率影响较大；而反应温度过高时，产物易碳化颜色发黑，产生较多的焦油副产物，从而使产品2-巯基苯并噻唑的含量降低；同时实验也发现：反应温度较高时，反应温度和压力较难控制，容易造成超压现象．因此，较佳的反应温度范围为240~260℃，最佳反应温度为250℃．2.2反应时间对产品收率的影响反应时间也是合成反应的重要影响因素，反应时间过长会引起副反应增多，反应时间过短则会导致反应不完全．按1.3所述的操作，设定反应温度为250℃，改变反应时间，考察不同反应时间对产品收率的影响，结果如图2所示．从图2中可以看出，在反应时间少于4h 范围内，随反应时间的增加，产品2-巯基苯并噻唑的收率逐步提高，原因可能是在此范围合成反应进行不够充分；当反应时间达到4h 左右时，2-巯基苯并噻唑的收率达到最大值；而后随反应时间延长，副产物增多，产品收率降低．因此，较佳的反应时间为4h ．(1)++++(2)图1反应温度对2-巯基苯并噻唑收率的影响Fig.1Effect of reaction temperature on the yield of 2-mercaptobenzothiazole 2002202402602808278747068/h收率/%第3期韩金平，等：2-巯基苯并噻唑的合成与固体吸附剂对合成反应的影响31 2.3合成原理分析苯胺／ｍｉｎ／ｍｉｎ32河北工业大学学报第38卷面积，使反应迅速、充分发生，从而显著提高反应速率，减少副反应发生的机会．在这3种吸附剂中活性炭的比表面积最大，吸附效果最好，所以反应时间最短；二氧化硅表面存在活性硅羟基（Si-OH ）[11]，是质子酸性表面，有利于产品2-巯基苯并噻唑的合成[5]，因此反应收率最高．2.5固体吸附剂用量对反应的影响固定其它反应条件，改变吸附剂用量，考察吸附剂用量对2-巯基苯并噻唑收率的影响，结果如图6所示．其中吸附剂活性氧化铝、二氧化硅、活性炭用量分别为反应物料总质量的0.5%、1%、1.5%、2%；添加活性氧化铝的合成反应时间为3.5h ，添加二氧化硅、活性炭的合成反应时间为3h ．由图6可以看出，随着吸附剂用量的增加，2-巯基苯并噻唑的收率有先升高再降低的趋势．说明加入一定量的吸附剂有助于加快反应，提高反应产物的收率，但吸附剂加入量过多，不但会使原料成本增加，同时会导致反应的选择性下降，副产物含量增加，产品的收率降低．由图6可以看出，吸附剂的选用量分别为：活性氧化铝3.1~4.7g ，约为反应物料总质量的1%~1.5%；二氧化硅3.1~6.3g ，约为反应物料总质量的1%~2%；活性炭1.5~4.7g ，约为反应物料总质量的0.5%~1.5%，合成的2-巯基苯并噻唑收率可达到85%左右．3结论采用苯胺-硝基苯混合法合成2-巯基苯并噻唑工艺，本文分别考察了反应温度和时间对产品收率的影响，确定了较佳反应温度为240~260℃（最佳250℃），反应时间为4h ，产品收率能达到80%左右．通过加入活性氧化铝、二氧化硅或活性炭固体吸附剂，获得了良好的催化效果：首先提高了产品2-巯基苯并噻唑的收率，由不加吸附剂时的80.6%提高到了85%以上，其中加入二氧化硅的反应收率最高，达到86.7%．其次缩短了反应时间，分别加入这3种吸附剂反应3h ，产品收率即能达到或超过不加吸附剂反应4h 的收率．由于活性氧化铝、二氧化硅、活性炭是3种常用的固体吸附剂，价廉易得，这将有利于苯胺-硝基苯混合法制备2-巯基苯并噻唑在工业生产中的推广应用．参考文献：[1]尹志刚，陈培同，钱恒玉．促进剂M 的合成及其应用进展[J ]．合成橡胶工业，2007，30（5）：398-402．[2]Makoto S ，Kenjiro M ，Morisue N ．Process for the rapid production of 2-mercaptobenzothiazole [P ]．US Patent ：3818025，1974-06-18．[3]Shaw C K ．Purification of mercaptobenzothiazole [P ]．US Patent ：4515957，1985-05-07．[4]奚国辉，王晓华．2-巯基苯并噻唑合成反应工艺研究[J ]．石化技术与应用，2003，21（4）：259-261．[5]Cobb A ，Peemans R ，Coenegrachts P ，et al ．Acid catalysed process for preparing 2-mercaptobenzothiazole and derivatives thereof [P ]．WO ：1997/046544，1997-12-11．[6]Reynolds ，Malz ．Method for the production of 2-mercaptobenzothiazole [P ]．US ：6222041，2001-04-24．[7]吴举祥．连续化合成粗品硫化促进剂M 工艺的改进[J ]．江苏化工，2007，35（1）：49-51．[8]李薇，吴凯涛．正交试验研究生产促进剂M 的主反应工艺条件[J ]．内蒙古石油化工，2005，9：12-13．[9]兰毅浩，李建州．高压M 后处理工艺分析[J ]．甘肃科技，2007，23（5）：76-77，80．[10]金福盛，甄中华．2-巯基苯并噻唑制造技术的进步[J ]．精细化工，1995，8（1）：39-41，52．[11]谢海安，戴宏程．超微细二氧化硅的改性研究及其应用[J ]．湖北化工，2001（5）：23-25．［责任编辑田丰］图5不同反应时间下吸附剂对2-巯基苯并噻唑收率的影响Fig.5Effects of adsorbent on the yield of 2-mercaptobenzothiazole at different reaction time Al 2O 3SiO 2活性C 对照9080706050收率/% 2.5h 3h 3.5h 4h 图6吸附剂用量对2-巯基苯并噻唑收率的影响Fig.6Effects of amount of adsorbents on the yield of2-mercaptobenzothiazole Al 2O 3SiO 2活性C 8880706050收率/%00.5%1%1.5%2%。

精细化工

The world fine chemical industry the most developed to push the United States, the federal republic of Germany and Japan, its product output, one of the world's first, two, three.
Development Status
According to statistics, there are 17 chemical enterprises in the global 500, before a few of them are the United States dupont, Germany basf, hurst and bayer company, the way of the companies in the United States and Switzerland ciba - fine base company, etc. They have more than hundred years of history, in the 1970 s used to develop the petrochemical industry, then turning to fine chemical industry. Germany is the country of the earliest development of fine chemical industry.
Development Direction
The 21st century is the era of knowledge economy, a biological engineering, information science and new material science mainly three frontier science of new technology revolution will have a significant impact on chemical industry. The development trend of traditional industries such as fine chemical industry is more and more increase intensive technical knowledge, and with the high and new technology complement each other.

表面化学官能团改性多孔碳(英文)

Recent Patents on Chemical Engineering 2008, 1, 27-40271874-4788/08 $100.00+.00© 2008 Bentham Science Publishers Ltd.Surface Chemical Functional Groups Modification of Porous CarbonWenzhong Shen*,1, Zhijie Li 2 and Yihong Liu 11State Key Laboratory of Heavy Oil, China University of Petroleum, Dongying, Shandong, 257061, P. R. China2Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054, P. R. ChinaReceived: August 29, 2007; Accepted: September 11, 2007; Revised: November 2, 2007Abstract: The surface chemistry and pore structure of porous carbons determine its application. The surface chemistry could be modified by various methods, such as, acid treatment, oxidization, ammonization, plasma, microwave treatment, and so on. In this paper, the modification methods were illustrated and compared, some new methods also reviewed. The surface chemical functional groups were determined by the treatment methods, the amminization could increase its basic property while the oxidization commonly improved its acids. In the end, the commonly characterization methods were also mentioned. Some interesting patents are also discussed in this article.Keywords: Porous carbon, surface chemical groups, modification, characterization. 1. INTRODUCTIONPorous carbons had been widely used as adsorbents, catalyst/catalyst supports, electronic material and energy storage material due to its higher surface area and larger pore volume.The specific surface area, pore structure and surface chemical functional groups of porous carbon determined its applications [1-2]. The pore structure of porous carbon could be controlled by various routes, such as, activation conditions (activation agent, temperature and time), precursor, templates, etc. The surface chemical functional groups mainly derived from activation process, precursor, heat treatment and post chemical treatment.The surface functional groups anchored on/within carbons were found to be responsible for the variety in physicochemical and catalytic properties of the matters considered [3-5]. So, many researchers focused on how to modify as well as to characterize the surface functional groups of carbon materials in order to improve or extend their practical applications [5-7]. Ljubisa R. Radovic reviewed the carbon materials as adsorbents in aqueous solution and pointed out that the control of chemical and physical conditions might be harnessed to produce carbon surfaces suitable for particular adsorption applications [8]. Carlos Moreno-Castilla compared the surface chemistry of the carbon has a great influence on both electrostatic and non-electrostatic interactions, and can be considered the main factor in the adsorption mechanism from dilute aqueous solutions [9].Modification of the surface chemistry of porous carbons might be a viable attractive route toward novel applications of these materials. A modified activated carbon containing*Address correspondence to this author at the State Key Laboratory of Heavy Oil, China University of Petroleum, Dongying, Shandong, 257061, P. R. China; Tel: +86-546-8395341; Fax: +86-546-8395395; E-mail: shenwzh2000@ different functional groups could be used for technological applications such as extracting metallic cations from aqueous and nonaqueous solutions, in catalysis, for treatment of waste and toxic effluents produced by a variety of chemical processes, and so on.The heteroatoms on the surface of activated carbon took significant role on its application. The heteroatoms of porous carbon surface mainly contained oxygen, nitrogen, hydrogen, halogen, etc, which bonded to the edges of the carbon layers and governed the surface chemistry of activated carbon [10]. Among these heteroatoms, the oxygen-containing functional groups (also denoted as surface oxides) were the widely recognized and the most common species formed on the surface of carbons, which significantly influenced their performance in sensors [11], energy storage and conversion systems [12-14], catalytic reactions [15], and adsorptions [16-18]. The surface oxygen-containing functional groups could be introduced by mechanical [19, 20], chemical [21, 22], and electrochemical routes [23]. The employment of oxidizing agents in wet or dry methods was reported to generate three types of oxygen-containing groups: acidic, basic, and neutral [24-27]. Based on the above modifications, a continuous supply of suitable oxidizing agents into the pores of a carbon matrix was believed to be a key factor determining the successful introduction of reliable oxygen-containing functional groups onto the surface of carbon materials.In addition, the nitrogen-containing groups generally provide basic property, which could enhance the interaction between porous carbon and acid molecules, such as, dipole-dipole, H-bonding, covalent bonding, and so on. The nitrogen groups were introduced by ammine treatment, nitric acid treatment and some containing nitrogen molecule reaction.In this review, we focused on the introducing oxygen and nitrogen heteroatoms on traditional porous carbon (activated carbon and activated carbon fiber) by various methods; the improved application property of modified porous carbon28 Recent Patents on Chemical Engineering, 2008, Vol. 1, No. 1 Shen et al. was also illustrated. In the end, the ordinarily character-rization means of oxygen and nitrogen groups were listed.2. METHODS FOR SURFACE MODIFICATIONThe nature and concentration of surface functionalgroups might be modified by suitable thermal or chemicalpost-treatments. Oxidation in the gas or liquid phase couldbe used to increase the concentration of surface oxygengroups; while heating under inert atmosphere might be usedto selectively remove some of these functions. It was shownthat gas phase oxidation of the carbon mainly increased theconcentration of hydroxyl and carbonyl surface groups,while oxidations in the liquid phase increased especially theconcentration of carboxylic acids [2]. Carboxyl, carbonyl,phenol, quinone and lactone groups on carbon surfaces wereshown in Fig. (1) [28].While, the ammonization could introduce the basicgroups, such as, C-H, C=N groups, amino, cyclic amides,nitrile groups, pyrrole-like structure [29]; which were shownin Fig. (2) [30]. In addition, the halogen-containing groupscould produce through porous carbon reacted with halogen atmoderate temperature, this modified porous carbon showedpotential application in electrochemistry or batteries [31].2.1. Acid TreatmentAcid treatment was generally used to oxidize the porouscarbon surface; it enhanced the acidic property, removed themineral elements and improved the hydrophilic of surface.The acid used in this case should be oxidization in nature;the nitric acid and sulfuric acid were the most selected.Liu et al. reported that coconut-based activated carbonwas modified by nitric acid and sodium hydroxide; it showedexcellent adsorption performance for Cr (VI) [32].Modification caused specific surface area to decrease and thetotal number of surface oxygen acidicgroups to increase. Nitric acid oxidization produced positiveacid groups, and subsequently sodium hydroxide treatmentreplaced H+ of surface acid groups by Na+, and the acidity ofactivated carbon decreased. The adsorption capacity of Cr(VI) was increased from 7.61mg/g to 13.88mg/g due to thepresence of more oxygen surface acidic groups and suitablesurface acidity after modification.Shim et al. also modified the pitch-based activatedcarbon fibers with nitric acid and sodium hydroxide [6]. Thespecific surface area of the activated carbon fibers decreasedafter oxidation with 1 M nitric acid, but the total acidityincreased three times compared to the untreated activatedcarbon fibers, resulting in an improved ion-exchangecapacity of the activated carbon fibers. The points of zerocharge of the activated carbon fibers that affect theselectivity for the ionic species changed from pH 6 to pH 4by 1 M nitric acid and to pH 10 by 1 M sodium hydroxidetreatment. The carboxyl acid and quinine groups wereintroduced after nitric acid oxidation. The carboxyl groups ofactivated carbon fibers decreased, while the lactone andketone groups increased after the sodium hydroxidetreatment. The adsorption capacity of copper and nickel ionis mainly influenced by the lactone groups on the carbonsurface, pH and by the total acidic groups.Coal-based activated carbons were modified by chemicaltreatment with nitric acid and thermal treatment undernitrogen flow [33]. The treatment with nitric acid caused theintroduction of a significant number of oxygenated acidicsurface groups onto the carbon surface, while the heattreatment increases the basicity of carbon. The porecharacteristics were not significantly changed after these Fig. (1). Simplified schematic of some acidic surface groups bonded to aromatic rings on AC [28].Fig. (2). The nitrogen functional forms possibly present in carbonaceous materials [30].H HO-Pyrrole Pyridine Pyridinium Pyridone Pyridine-N-oxideHCarboxyl Quinone HydroxylCarbonyl Carboxylic anhyride LactoneSurface Chemical Modification of Porous Carbon Recent Patents on Chemical Engineering, 2008, Vol. 1, No. 1 29modifications. The dispersive interactions are the most important factor in this adsorption process. Activated carbon with low oxygenated acidic surface groups has the best adsorption capacity for benzene and toluene.The coconut-based activated carbon was pretreated with different concentrations of nitric acid (from 0.5 to 67%) and was selected as palladium catalyst support [34], the result showed that the amount of oxygen-containing groups and the total acidity on the activated carbons, the Pd particle size and catalytic activity of Pd/C catalysts are highly dependent upon the nitric acid concentration used in the pretreatment. The pretreatment of activated carbon with a low concentration of nitric acid could increase the structure parameters due to removal of the impurities, would be beneficial to create an appropriate density of total acidity environment, and would further improve the Pd dispersion and the catalytic activity of Pd/C catalysts. Meanwhile, a too-large amount of oxygen-containing groups assembling densely on the activated carbon could influence the Pd dispersion on the activated carbon well.Peach stone shells were pretreated by H3PO4 and pyrolysis at 500o C for 2 h, then, it was prepared by changing the gas atmosphere during thermal treatment (no external gas, flowing of nitrogen, carbon dioxide, steam or air [35]. High uptake of p-nitrophenol appears, affected to low extent with gaseous atmosphere except steam which raises adsorption considerably. Flowing air was the most effective in enhancing the adsorption of methylene blue, which was attributed to the formation of oxygen-functionalities with acidic nature, and to enhancement of wider microporosity. The removal of lead ions was considerably enhanced by running air during thermal treatment (two-fold increase) due to the formation of acidic oxygen-functionalities associated with metal exchange by the negatively charged carbon surface. Li describes the method of eliminating residual carbon from flow able oxide [36].The activated carbon derived from poly(VDC/MA) was treated with HNO3/H2SO4 solutions and heat-treatment in Ar [37]. Acid-treatment increased the adsorption of methyl mercaptan compared with the original activated carbon, and the adsorbed amounts increased with ratio of H2SO4 in HNO3/H2SO4 solutions. Hydrogen bonding between acidic groups formed by acid-treatment and thiol-groups methyl mercaptan played a role in adsorption of methyl mercaptan on activated carbon. Hasenberg et al. shows a process and catalyst blend for selectively producing mercaptans and sulfides from alcohols [38].Surface modification of a coal-based activated carbon was performed using thermal and chemical methods [39]. Nitric acid oxidation of the conventional sample produced samples with weakly acidic functional groups. There was a significant loss in microporosity of the oxidized samples which was caused by humic substances that were formed as a by-product during the oxidation process. However, thermal treatment produced a carbon with some basic character while amination of the thermally treated carbon gave a sample containing some amino (-NH2) groups.The formation of the weakly acidic functional groups on porous carbon surface were thought to be similar to the reaction involving the oxidation of 9,10-dihydrophen-anthrene and diphenylmethane with nitric acid [40], and the mechanism was displayed in Fig. (3). The formation of the dicarboxylic group was thought to occur on the aliphatic side of the molecule especially if the side chains consisted of more than one carbon atom (reaction (a)). The reaction was initiated by the splitting of the C-C at the a-position of the benzylic carbon atom. Oxidation involving a methylene (-CH2-) group would result in the formation of a ketone as shown in reaction (b). Nitrogen could be added to the carbon by a similar reaction as in the nitration of benzene. The mechanism would involve the formation of the highly reactive nitronium ion (NO2-), which would ultimately form the nitrated product as shown in reaction (c).The amination reaction was achieved via a two stage process. The first stage was the nitration stage where the nitric acid was mixed with concentrated sulphuric acid to form the nitronium ions which then reacted via electrophilic substitution of the hydrogen ion of the carbon matrix as shown in reaction (d). The formed nitro-species formed was reduced using a suitable reducing agent and in this case sodium dithionite was employed. This result then showed the effectiveness of the reduction reaction shown in reaction (e). This modification process was another example of the application of a classic organic reaction on activated carbon modification. The reaction was shown in the illustration of the amination of phenanthrene.Calvo et al. reported that the surface chemistry of commercial activated carbon was one of the factors determining the metallic dispersion and the resistance to sintering, being relevant the role of surface oxygen groups [41]. The surface oxygen groups were considered to act as anchoring sites that interacted with metallic precursors and metals increasing the dispersion, with CO-evolving complexes significantly implied in this effect. On the other hand, CO2-evolving complexes, mainly carboxylic groups, seemed to decrease the hydrophobicity of the support improving the accessibility of the metal precursor during the impregnation step. The treatment of activated carbons with nitric acid led to a higher content in oxygen surface groups, whereas the porous structure was only slightly modified. As a result of oxidation, the dispersion of Pd on the surface of activated carbon was improved.Santiagoet al. compared several activated carbons for the catalytic wet air oxidation of phenol solutions [42]. Two commercial activated carbons were modified by HNO3, (NH4)2S2O8, or H2O2 and by demineralisation with HCl. The treatments increased the acidic sites, mostly creating lactones and carboxyls though some phenolic and carbonyl groups were also generated. Characterisation of the used activated carbon evidenced that chemisorbed phenolic polymers formed through oxidative coupling and oxygen radicals played a major role in the catalytic wet air oxidation over activated carbon.Also, citric acid was used to modify a commercially available activated carbon to improve copper ion adsorption from aqueous solutions [25]. It was found that the surface modification by citric acid reduced the specific surface area by 34% and point of zero charge (pH) of the carbon by 0.5 units. But the modification did not change both external diffusion and intraparticle diffusion.30 Recent Patents on Chemical Engineering, 2008, Vol. 1, No. 1 Shen et al.2.2. Ammonia TreatmentIt was well known that nitrogen-containing surfacegroups gave to activated carbons increased ability to adsorb acidic gases [43]. Practically, nitrogen was introduced intostructure of activated carbon according to several proceduresincluding treatment with ammonia or preparation of theadsorbent from nitrogen-containing polymers (Acrylictextile, polyaryamide or Nomex aramid fibers) [44-46].Heating of phenol-formaldehyde-based activated carbon fiber in the atmosphere of dry ammonia at severaltemperatures ranged from 500o C to 800o C resulted in aformation of new nitrogen-containing groups in the structureof the fiber including C-N and C=N groups, cyclic amides,nitrile groups (C N) [47], and pyrrole-like surface structures with N-H groups [48]. Despite the changes in the surface chemistry, an outcome of heating of activatedcarbons in ammonia atmosphere might also be changed inporosity of the treated carbon. As it reported, extensive heat-treatment with gaseous ammonia might cause changes in therelative amounts of macropore, mesopore and micropores ofcommercial activated carbon [42].In any case, since introducing of nitrogen-containingsurface groups made activated carbon more alkaline and soincreased adsorption of acidic agents is expected.The commercial activated carbons were treated by gaseous NH3 ranging from 400o C to 800o C for 2 h [49]. The CH and CN groups appeared after NH3 treatment. It demonstrated enhanced adsorption of phenol from water due to the formation of nitrogen-containing groups during ammonia-treated, which could form hydrogen bond with phenol.A series of activated carbon fibers were produced by treatment with ammonia to yield a basic surface [47]. The adsorption isotherms of an acidic gas (HCl) showed a great improvement in capacity over an untreated acidic fiber. The adsorption was completely reversible and therefore involved the enhanced physical adsorption instead of chemisorption. This demonstrated that activated carbon fibers could be tailored to selectively remove a specific contaminant (acidic gas) based on the chemical modification of their pore surfaces.Commercial activated carbon and activated carbon fiber were modified by high temperature helium or ammonia treatment, or iron impregnation followed by high temperature ammonia treatment [50]. Iron-impregnated and ammonia-treated activated carbons showed significantly higher dissolved organic matter uptakes than the virgin activated carbon. The enhanced dissolved organic matter uptake by iron-impregnated was due to the presence of iron species on the carbon surface. The higher uptake of ammonia treated was attributed to the enlarged carbon pores and basic surface created during ammonia treatment.A commercial raw granular activated carbon was modified by polyaniline to improve arsenate adsorption [51].Fig. (3). The formation of acidic functional groups by nitric acid and amination reaction by thermal treatment [38].5HNO32HNO3HNO3HNO3NH3NO22HNO2+++++H2O24+OHH2OHH(a)(b)(c)(d)(e)224OOHO++Surface Chemical Modification of Porous Carbon Recent Patents on Chemical Engineering, 2008, Vol. 1, No. 1 31It was found that the modification did not change the specific surface area. The content of the aromatic ring structures and nitrogen-containing functional groups on the modified granular activated carbon was increased. The surface positive charge density was dramatically increased in acidic solutions. The presence of humic acid did not have a great impact on the arsenic adsorption dynamics. The modification significantly enhanced the adsorption of humic acid onto the carbon. Meanwhile, the arsenate was reduced to arsenite during the process.Lin et al. provided a method for minute deposition of polyaniline onto microporous activated carbon fabric could enhance the capacitance of the carbon serving as electrodes for electrochemical capacitors [52]. The result demonstrated that a capacitance enhancement of 50% in comparison with bare carbon could be achieved with minute polyaniline deposition (5wt%) using the deposition method, while only 22% was reached using the conventional method.2.3. Heat TreatmentThe nature and concentration of surface functional groups might be modified by suitable thermal or chemical post-treatments. Heating oxidation in the gas or liquid phase could be used to increase the concentration of surface oxygen groups, while heating under inert atmosphere might be used to selectively remove some of these functions. Thermal treatments had been used to produce activated carbons with basic character and such carbons were effective in the treatment of some organic hydrocarbons [53].Heat treatment of carbon in an inert atmosphere or under inert atmospheres (hydrogen, nitrogen or argon) flow could increase carbon hydrophobicity by removing hydrophilic surface functionalities, particularly various acidic groups [54-57]. It had been shown that H2 was more effective than inert atmospheres because it could also effectively stabilize the carbon surface by deactivation of active sites (i.e., forming stable C-H bonds and/or gasification of unstable and reactive carbon atoms) found at the edges of the crystallites. H2 treatment at 900o C could produce highly stably and basic carbons [52, 55], and the presence of a platinum catalyst could considerably lower the treatment temperature [56]. H2-treated carbons were expected to demonstrate much lower reactivity toward oxygen or chemical agents compared to carbons that were heat-treated in an inert atmosphere. The hydrophobic porous carbon effectively removed the non-polar organic molecules from aqueous solution. However, in order to prepare hydrophobic porous carbon, it needed high temperature and inert/reductive atmospheres to remove the heteroatoms on the surface of porous carbon.The wood, coal-based activated carbons and a commer-cial activated carbon fiber with different physicochemical characteristics were subjected to heat treatment at 900o C under vacuum or hydrogen flow [58]. Oxygen sorption experiments showed lower amounts of oxygen uptake by the H2-treated than by the vacuum-treated carbons, indicating that H2 treatment effectively stabilized the surfaces of various carbons. At low pressures, from 0.001 mmHg to 5 mmHg, adsorption of oxygen was governed by irreversible chemisorption, which was well described by the Langmuir equation. At higher pressures oxygen uptake occurred as a result of physisorption, which was in agreement with Henry’s law. Kinetic studies showed that oxygen chemisorp-tion was affected by both carbon surface chemistry and porosity. The results indicated that oxygen chemisorption initially started in the mesopore region from the high energetic sites without any mass transfer limitation; thus a constant oxygen uptake rate was observed. Once the majo-rity of these sites were utilized, chemisorption proceeded toward the less energetic sites in mesopores as well as all the sites located in micropores. As a result, an exponential decrease in the oxygen uptake rate was observed.Different precursors resulted in various elemental compositions and imposed diverse influence upon surface functionalities after heat treatment. The surface of heat-treated activated carbon fibers became more graphitic and hydrophobic. Polyacrylonitrile- and rayon-based activated carbon fibers subjected to heat treatment [59]. The presence of nitride-like species, aromatic nitrogen-imines, or chemi-sorbed nitrogen oxides was found to be of great advantage to adsorption of water vapor or benzene, but the pyridine-N was not. Unstable complexes on the surface would hinder the fibers from adsorption of carbon tetrachloride. The rise in total ash content or hydrogen composition was of benefit to the access of water vapor.2.4. Microwave TreatmentThe main advantage of using microwave heating was that the treatment time could be considerably reduced, which in many cases represented a reduction in the energy con-sumption. It was reported that microwave energy was derived from electrical energy with a conversion efficiency of approximately 50% for 2450 MHz and 85% for 915 MHz [60].Thermal treatment of polyacrylnitrile activated carbon fibers had been carried out using a microwave device [61]. Microwave treatment affected the porosity of the activated carbon fibers, causing a reduction in micropore volume and micropore size. Moreover, the microwave treatment was a very effective method for modifying the surface chemistry of the activated carbon fibers with the production of pyrone groups. As a result very basic carbons, with points of zero charge approximately equal to 11, were obtained.Microwave heating offered apparent advantages for activated carbon regeneration, including rapid and precise temperature control, small space requirements and greater efficiency in intermittent use [62]. Quan et al. investigated the adsorption property of acid orange 7 by microwave regeneration coconut-based activated carbons[63]. It was found that after several adsorption-microwave regeneration cycles, the adsorption rates and capacities of granular activated carbons could maintain relatively high levels, even higher than those of virgin Granular activated carbons. The improvement of granular activated carbons adsorption properties resulted from the modification of pore size distribution and surface chemistry by microwave irradiation.2.5. Ozone TreatmentOzone as a strong oxidization agent was widely applied in organic degradation; it could also oxidize the carbon material surface to introduce oxygen-containing groups. The32 Recent Patents on Chemical Engineering, 2008, Vol. 1, No. 1 Shen et al.ozone dose and oxidization time affected the resultant oxygen-containing groups and the oxygen concentration on the carbon surface. The result of bituminous origin-based activated carbon oxidization with ozone showed that the higher the ozone dose, the higher was the oxidation of the carbon and the greater was the number of acid groups present on the carbon surface, especially carboxylic groups, whereas the pH of the point of zero charge decreased [64]. The surface area, micropore volume, and methylene blue adsorption all reduced with higher doses. These results were explained by the ozone attack on the carbon and the fixation of oxygen groups on its surface. Jackson introduces a method for supercritical ozone treatment of a substrate [65].The impact of ozonation on textural and chemical surface characteristics of two coal-based activated carbons and their ability to adsorb phenol, p-nitrophenol, and p-chlorophenol from aqueous solutions had been investigated by Alvarez et al. [66]. The porous structure of the ozone-treated carbons remained practically unchanged with regard to the virgin activated carbon. At 25o C primarily carboxylic acids were formed while a more homogeneous distribution of carboxylic, lactonic, hydroxyl, and carbonyl groups was obtained at 100o C.2.6. Plasma TreatmentThe plasma treatment was regarded as a promising technique to modify the surface chemical property of porous carbon since it produced chemically active species affecting the adsorbability. During the plasma treatment, the slower chemical reaction by chemically active species took place only on the surface of activated carbon without changing its bulk properties at low pressure by long time treatments. It was possible to create any ambiance for oxidative, reductive, or inactive reaction by changing the plasma gas [67]. Plasma could introduce basic and acid functional groups that were determined by the gaseous resource. The semi-quantitative analysis of the surface acidic functional groups showed that a difference in treatment conditions affected the quality and quantity of the functional groups [68].Some experimental efforts had been reported on activated carbon treatment with oxygen-included plasmas. The negative charge of activated carbon was brought after the plasma treatment was due to dissociation of newly formed acidic groups. The hydrophilicity of plasma-treated carbons did not change significantly. The oxygen plasma appeared not to reach the smallest micropores of the carbon, indicating that the reaction took place only near the external surfaces of the particles [69, 70]. The surface area of activated carbon that was treated by oxygen non-thermal plasma was decreased, and the concentrations of acidic functional groupsat the surface were increased and the saturated adsorption amount of copper and zinc ion was considerably increased [71-74]. Oxygen species produced during the discharge react on the activated carbon surface resulting in the creation of weakly acidic functional groups that played an important role in adsorbing metal cations. Improvement in the adsorbability was attributed to the change in the surface chemical structure of the commercial activated carbon rather than the modification of the surface physical structure [75]. For example, the CF4 plasma treatment could effectively improve the hydrophobic property, polarization and power density of the activated carbon fibers [76]. The activation of the carbon-surface by the nitrogen radio frequency plasma yielded a significant increase in adhesion for Cu-coatings [77]. The submicron vapor grown carbon fibers preserved their general smoothness upon plasma oxidation and the structural changes brought about by this treatment essentially took place only at the atomic scale [78]. The vapor grown carbon fibers were modified using NH3, O2, CO2, H2O and HCOOH plasma gases to increase the wettability and the results show that the oxidation strength was O2>CO2>H2O>HCOOH [79]. The polyacrylonitrile fibers were treated with the nitrogen glow discharge plasma and the hydrophilic groups (N-H, C=N) were introduced on the fiber surfaces [80]. The air and nitrogen glow discharge were usedto modify the activated carbon fibers, their surface became rough and several types of polar oxygen groups were introduced into the carbon fiber surface [81].The invention by Miller et al. induces the steps of evaporation for regeneration of commercial activated carbon[82].Viscose-based activated carbon fibers were treated by a dielectric-barrier discharge plasma and nitrogen as deed gas at different conditions [83]. It showed that the nitrogen plasma modification could remarkably change the distribution of the oxygen functional groups on the activated carbon fibers surface and there were more nitrogen atoms incorporated into the aromatic ring.Different plasma treatment and the changes of related chemical functional groups were listed in Table 1.In addition, space charge density could be improved by nitrogen plasma surface treatment of carbon materials [84].Recently, atmospheric pressure plasma could treat various materials even those which were low temperatureTable 1. The Related Chemical Groups Change at Different Plasma Treatment ConditionsPlasma gaseous Increased chemical groups Decreased chemical groups O2– C-OOH, C=O – C-OH, C-O-C [72]N2– C-OH, C-O-C–, O=C-O, pyridine and quaternary nitrogen – C=O (aromatic ring) [79]NH3 N-H[70]CO2– C-OOH, C=O [76]H2O – C-OOH, C=O [76]。

The ACS Style Guide

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ix Contributors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiii
appendix 5-2: Key Features of Selected Online Submission Systems. . . . . . . . .68 6. Peer Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
appendix 3-1: Proofreaders’ Marks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4. Writing Style and Word Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5. Electronic Submission of Manuscripts Using Web-Based Systems. . . . . . . 59

宁波2024年05版小学六年级下册T卷英语上册试卷(含答案)

宁波2024年05版小学六年级下册英语上册试卷(含答案)考试时间：80分钟（总分:120）A卷考试人：_________题号一二三四五总分得分一、综合题(共计100题)1、填空题：I can ______ (定期) reflect on my progress.2、填空题：The turtle swims slowly in the _______ (水).3、填空题：A __________ (催化循环) enhances reaction efficiency in chemical processing.4、What do you call a person who plays a musical instrument?A. MusicianB. SingerC. ComposerD. Conductor答案:A5、听力题：The chemical formula for calcium hydroxide is _______.6、How do you say "hand" in Spanish?A. ManoB. MainC. HandD. Maño7、听力题：The main gas in the air we breathe is _____.8、填空题：The ________ was a significant period in the evolution of human rights.The ________ (jacket) keeps me warm.10、填空题：Certain plants can ______ (抵抗) pests naturally.11、听力题：A _______ can be a beautiful centerpiece for a table.12、听力题：We eat ______ (snacks) during recess.13、听力题：A liquid that can dissolve a solute is called a _______.14、What is 3 + 5?A. 6B. 7C. 8D. 9答案:C15、填空题：Julius Caesar was a famous Roman _______. (统治者)16、听力题：A solution that contains the maximum amount of solute is _____ (saturated).17、What is the name of the famous ancient city in Iraq?A. BabylonB. NinevehC. UrD. All of the above18、听力题：The Magna Carta was signed in _______.19、What do we call the process of a caterpillar becoming a butterfly?A. MetamorphosisB. TransformationC. EvolutionD. Development答案:A20、填空题：I can ______ (表达) my thoughts clearly.The chemical symbol for rubidium is __________.22、听力题：The study of chemicals and their reactions is known as _______.23、What is the name of the famous explorer who sailed across the ocean in 1492?A. Vasco da GamaB. Ferdinand MagellanC. Christopher ColumbusD. Marco Polo答案:C24、What is the name of the famous ancient city in Jordan?A. PetraB. BabylonC. AthensD. Rome答案:A25、填空题：I want to grow _____ (蔬菜) this year.26、填空题：We can play with a ________ outside.27、选择题：What do you call the part of the plant that absorbs water?A. LeafB. StemC. RootD. Flower28、听力题：We enjoy going to the ___. (beach) every summer.29、听力题：A mixture that contains two or more phases is called a ______.30、What is the capital of Canada?A. TorontoB. OttawaC. VancouverD. MontrealI like to _______ (与朋友一起)去健身房。

化学专业英语-Biochemistry

（2） Building molecules（构件分子）
（3） Biomacromolecules（生物大分子）
常见的功能基团
Functional groups
1) Functional groups are clusters of atoms with characteristic structure and functions. 2) Most biomolecules contain more than one functional group. 3) Different families of organic compounds result when hydrogen atoms on organic molecules are replaced by different functional groups. 4) The distinct chemical properties of each functional group contribute to the behavior of any molecule that contains it.
Fatty acids
Phospholipids 磷脂
Phospholipids are modified so that a phosphate group (PO4-) is added to one of the fatty acids. The addition of this group makes a polar "head" and two nonpolar "tails".
Polysaccharides
These classes perform a variety of

常见国际组织会议名称

常见国际组织会议名称政治类:不结盟运动Non-Aligned Movement - NAM各国议会联盟Inter-Parliamentary Union -- IPU阿拉伯国家联盟League of Arab States - LAS伊斯兰会议组织Organization of the Islamic Conference - OIC东南亚国家联盟Association of Southeast Asian Nations - ASEAN南亚区域合作联盟South Asian Association for Regional Cooperation - SAARC欧洲联盟European Union - EU西欧联盟Western European Union - WEU非洲联盟African Union - AU非洲统一组织Organization of African Unity - OAU美洲国家组织Organization of American States - OAS；Organizacion de los Estados Americanos - OEA亚洲议会和平协会The Association of Asian Parliaments for Peace - AAPP独联体Commonwealth of Independent States - CIS上海合作组织Shanghai Cooperation Organization - SCO海湾合作委员会Gulf Cooperation Council - GCC国际刑事法院International Criminal Court - ICC国际移民组织International Organization for Migration - IOM政府间移民委员会Intergovernmental Committee for Migration - ICM 英联邦The Commonwealth欧洲安全与合作组织Organization for Security and Co-operation in Europe - OSCE澳新美理事会ANZUS council巴黎俱乐部Paris Club前政府首脑国际行动理事会Inter Action Council of Former Heads of Government - ICFHG里约集团The Rio Group北大西洋公约组织（北约）North Atlantic Treaty Organization - NATO 七十七国集团Group of 77 - G77加勒比国家联盟Association of Caribbean States - ACS拉丁美洲议会Latin-American Parliament阿拉伯各国议会联盟Arab Inter-Parliamentary Union - AIPU巴黎统筹委员会（输出管制统筹委员会）Co-Ordinating Committee for Export Control社会党国际Socialist International - SI自由进步党国际Liberal International - LI国际刑事警察组织International Criminal Police Organization - INTERPOL联合国协会世界联合会World Federation of United NationsAssociation - WFUNA亚洲议会论坛The Asia-Pacific Parliamentary Forum - APPF葡语国家共同体Community of Portuguese-speaking Countries - CPLP 中欧倡议国组织Central European Initiative - CEI维谢格拉德集团Visegrad Group波罗的海国家理事会Council of the Baltic Sea States - CBSS阿拉伯马格里布联盟Union of the Arab Maghreb；Union du Maghreb Arabe - UMA桑戈委员会Zangger Committee - ZAC核供应国集团Nuclear Suppliers Group - NSG禁止化学武器组织Organization for the Prohibition of Chemical Weapons - OPCW法语国家国际组织Organisation Internationale de la Francophonie伊比利亚美洲国家首脑会议Ibero-American Summit华沙条约组织（华约）Warsaw Treaty Organization - WTO中国－阿拉伯国家合作论坛The China-Arab Cooperation Forum南美国家共同体South American Community of Nations - CSN经济类:世界贸易组织（世贸组织）World Trade Organization - WTO经济合作与发展组织（经合组织）Organization for EconomicCooperation and Development - OECD亚太经合组织Asia-Pacific Economic Cooperation - APEC世界旅游组织World Tourism Organization石油输出国组织Organization of Petroleum Exporting Countries - OPEC阿拉伯石油输出国组织Organization of Arab Petroleum Exporting Countries - OAPEC国际能源机构International Energy Agency - IEA世界能源理事会World Energy Council - WEC反洗钱金融行动特别工作组Financial Action Task Force on Money Laundering - FATF关税及贸易总协定（关贸总协定）General Agreement on Tariffs and Trade - GATT国际航空运输协会International Air Transport Association - IA TA亚洲开发银行Asian Development Bank - ADB非洲开发银行African Development Bank - ADB美洲开发银行Inter-American Development Bank - IDB加勒比开发银行Caribbean Development Bank - CDB欧洲复兴开发银行European Bank for Reconstruction and Development - EBRD欧洲中央银行European Central Bank - ECB国际复兴开发银行（世界银行）International Bank for Reconstructionand Development - IBRD (World Bank)比荷卢经济联盟Union Economique Benelux欧洲自由贸易联盟European Free Trade Association - EFTA环印度洋地区合作联盟Indian Ocean Rim Association for Regional Cooperation -- IOR-ARC太平洋共同体Pacific Community - PC太平洋岛国论坛Pacific Islands Forum东南非共同市场Common Market for Eastern and Southern Africa - COMESA南部非洲发展共同体Southern African Development Community - SADC大湖国家经济共同体Economic Community of the Great Lakes Countries非洲发展新伙伴计划The New Partnership for Africa's Development - NEPAD)西非国家经济共同体Economic Community of West African States - ECOW AS西非经济货币联盟West African Economic and Monetary Union东非合作组织East African Cooperation - EAC东非政府间发展组织（伊加特）Inter-Governmental Authority on Development - IGAD中部非洲国家经济共同体Economic Community of Central AfricanStates - ECCAS大湄公河次区域经济合作GMS Summit国际展览局Bureau of International Expositions - BIE安第斯共同体Andean Community南方共同市场South American Common Market- MERCOSUR拉丁美洲经济体系Latin Aamerican Economic System - LAES拉丁美洲一体化协会Latin American Integration Association - LAIA 拉丁美洲自由贸易协会Asociacion Latinoamericana de Libre Comercio - ALALC加勒比共同体和共同市场Caribbean Community and Common Market - CARICOM中美洲一体化体系Central American Integration System - SICA非洲、加勒比和太平洋地区国家集团（非加太集团）Group of African, Caribbean and Pacific Region Countries - Group of the ACP博鳌亚洲论坛Boao Forum for Asia - BFA十国集团（巴黎俱乐部）Group-10 (Paris Club)15国集团（南南磋商与合作首脑级集团）Group 15 (Summit Level Group for South-South Consultation and Cooperation)20国集团Group 2024国集团Group of Twenty Four - G24科技文化等专业类:国际战略研究所International Institute for Strategic Studies - IISS国际奥比斯组织Project Orbis - ORBIS第三世界科学院Third World Academy of Sciences - TW AS国际科学理事会International Council for Science - ICSU国际红十字会与红新月会联合会International Federation of Red Cross and Red Crescent Societies国际大学协会International Association of Universities - IAU国际档案理事会International Council on Archives - ICA国际图书馆协会联合会International Federation of Library Associations and Institutions - IFLA国际交流发展计划International Programme for the Development of Communication - IPDC国际世界语协会Universal Esperanto Association - UEA世界厕所组织World Toilet Organization国际新闻学会International Press Institute - IPI国际新闻工作者协会International Organization of Journalists - IOJ；Organisation Internationale des Journalistes - 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电化学二电子氧还原制备过氧化氢研究进展

物理化学学报Acta Phys. -Chim. Sin. 2024, 40 (2), 2304001 (1 of 11)Received: April 3, 2023; Revised: May 16, 2023; Accepted: May 17, 2023; Published online: May 29, 2023. *Correspondingauthors.Emails:**************.cn(N.H.);*****************.cn(Y.L.)The project was supported by the National Natural Science Foundation of China (U2002213, 52161160331, 2227090515). 国家自然科学基金(U2002213, 52161160331, 2227090515)资助项目© Editorial office of Acta Physico-Chimica Sinica[Perspective] doi: 10.3866/PKU.WHXB202304001 Recent Progress towards the Production of H 2O 2 by Electrochemical Two-Electron Oxygen Reduction ReactionZhaoyu Wen 1, Na Han 1,*, Yanguang Li 1,2,*1 Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, Jiangsu Province, China.2 Macao Institute of Materials Science and Engineering, Macau University of Science and Technology, Taipa 999078,Macau SAR, China.Abstract: Hydrogen peroxide (H 2O 2) is an important chemical and has been extensively used in various industrial and manufacturing applications, such as wastewater treatment, sterilization, energy storage, and oxidation of small molecules. With increasing demand in various fields, the global hydrogen peroxide market is expected to grow to $8.9 billion by 2031. Currently, over 90% of H 2O 2 is industrially synthesized by the anthraquinone process, which requires complex infrastructure and expensive catalysts. Additionally, the anthraquinone process is energy intensive and leads to increased levels of environmental pollution. Although the direct synthetic process, which involves mixing hydrogen and oxygen, can achieve high atomicutilization, its development is limited due to explosion risk and high cost. Thus, there is a pressing need for a safe, cost-effective, and efficient industrial method for the production of H 2O 2. The electrochemical synthesis of H 2O 2 via a two-electron oxygen reduction reaction (2e − ORR) has emerged as an attractive method for the decentralized production of H 2O 2, which could effectively address the issues associated with the indirect anthraquinone and direct synthetic processes. However, sluggish reaction kinetics and poor selectivity decrease the energy efficiency of electrochemical H 2O 2 synthesis. In this regard, developing electrocatalysts with high 2e − ORR selectivity is vital for the efficient production of H 2O 2. In the past decades, extensive efforts have been devoted to developing effective 2e − ORR electrocatalysts such as noble metals/alloys, carbon-based materials, single-atom catalysts, and molecular complexes. However, the reported catalysts still have unsatisfactory catalytic performances. Therefore, there is still a long way to realize the large-scale production of H 2O 2 via electrochemical 2e − ORR pathway. In this perspective, we systematically summarize recent developments regarding the direct production of H 2O 2 through electrochemical two-electron oxygen reaction. First, the fundamental aspects of electrochemical 2e − ORR are discussed, including their reaction mechanisms, possible reaction pathways, testing techniques and performance figures of merit. This introduction is followed by detailed discussions on the different types of 2e − ORR electrocatalysts, with an emphasis on the underlying material design principles used to promote reaction activity, selectivity, and stability. Subsequently, the applications of electrosynthetic hydrogen peroxide in various fields are briefly described, including pollutant degradation, water sterilization, energy storage, and small-molecule synthesis. Finally, potential future directions and prospects in 2e − ORR catalysts for electrochemically producing H 2O 2 are examined. Key Words: Electrochemical; 2e − oxygen reduction reaction; Hydrogen peroxide; Catalyst; Selectivity电化学二电子氧还原制备过氧化氢研究进展文兆宇1，韩娜1,*，李彦光1,2,*1苏州大学功能纳米与软物质研究院，江苏苏州 2151232澳门科技大学材料科学与工程研究院，澳门氹仔岛 999078摘要：利用电化学二电子氧还原(2e− Oxygen Reduction Reaction，2e− ORR)方法实现过氧化氢(H2O2)的分散式制备，被认为是具有广阔发展前景的技术之一。

中文翻译

Proceedings of the Combustion InstituteV olume 32, Issue 1, 2009, Pages 229-237doi:10.1016/j.proci.2008.05.005 | How to Cite or Link Using DOICopyright © 2009 Elsevier Inc. All rights reserved.Permissions & ReprintsA chemical kinetic study of n-butanol oxidation at elevated pressure in a jet stirred reactorP. Dagauta, S.M. Sarathyb and M.J. Thomsonb, ,aCNRS, 1C, Avenue de la recherche scientifique, 45071 Orléans Cedex 2, France bDepartment of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, Ont., Canada M5S 3G8Available online 20 September 2008.AbstractBiofuels are attractive alternatives to petroleum derived transportation fuels. n-Butanol,or biobutanol, is one alternative biofuel that can replace gasoline and diesel in transportation applications. Similar to ethanol, n-butanol can be produced via the fermentation of sugars, starches, and lignocelluloses obtained from agricultural feedstocks. n-Butanol has several advantages over ethanol, but the detailed combustion characteristics are not well understood. This paper studies the oxidation of n-butanol in a jet stirred reactor at 10 atm and a range of equivalence ratios. The profiles for CO, CO2, H2O, H2, C1–C4 hydrocarbons, and C1–C4 oxygenated compounds are presented herein. High levels of carbon monoxide, carbon dioxide, water, hydrogen, methane, formaldehyde, ethylene, and propene are detected. The experimental data are used to validate a novel detailed chemical kinetic mechanism for n-butanol oxidation. The proposed mechanism well predicts the concentration of major product species at all temperatures and equivalence ratios studied. Insights into the prediction of other species are presented herein. The proposed mechanism indicates that n-butanol consumption is dominated by H-atom abstraction from the α, β, and γ carbon atoms. A sensitivity analysis is also presented to show the effects of reaction kinetics on the concentration of several poorly predicted species. Keywords: n-Butanol; 1-Butanol; Jet stirred reactor; Kinetic modeling; Reaction mechanism Article Outline1.Introduction2.Experimental methods3.Computational methods4.Results and discussion5.ConclusionsAcknowledgementsAppendix A.Supplementary dataReferences1. IntroductionA potential biofuel for use in both gasoline and diesel engines is n-butanol.Historically, industrial scale production of n-butanol from biomass feedstocks was the second largest fermentation process, exceeded only by ethanol. However, its demise was brought about in the early 1960s when petroleum derived n-butanol became more economically feasible [1]. Recent advances in n-butanol production in the laboratory have spurred interest in commercial scale production of the n-butanol[2] and [3]. Recently, BP and Dupont announced that they would commercially produce n-butanol,which they call biobutanol, as a gasoline blending component for automotive fuels [4] and [5]. n-Butanol is produced via a fermentation process similar to that of ethanol, and therefore its feedstocks could include sugar beet, sugar cane, corn, wheat and also cellulosic biomass. n-Butanol has several advantages over ethanol including enhanced tolerance to water contamination allowing the use of existing distribution pipelines, the ability to blend at higher concentrations without retrofitting vehicles, and better fuel economy.Relatively few engine studies of n-butanol have been published. Yacoub et al. used gasoline blended with a range of C1–C5 alcohols (including n-butanol)to fuel a single-cylinder spark ignition (SI) engine [6]. They found that the n-butanol blends had less knock resistance than neat gasoline. The n-butanol blends also had reduced CO and hydrocarbon emissions but increased NOx emissions. This may be due to the n-butanol blends having a higher flame temperature and earlier spark timing. Of particular interest to the present study is that the primary oxygenated hydrocarbon emissions were n-butanol,formaldehyde and to a lesser extent, acetaldehyde. A study by Miller et al. successfully operated unmodified gasoline and diesel engines on blends containing 0–20% n-butanol in gasoline and 0–40% n-butanol in diesel fuel [7]. Another study successfully ran a compression ignition (CI) engine fueled with n-butanol and diesel fuel microemulsions [8].Predictive models provide a better understanding of the combustion performance and emissions characteristics of biofuel compositions and why they differ from petroleum derived materials. The development of an n-butanol model requires understanding of its fundamental pyrolysis and oxidation kinetics. However, few studies have examined the combustion chemistry of n-butanol, while none have developed a detailed chemical kinetic mechanism of the fuel. A 1959 study by Barnard examined the pyrolysis of n-butanol[9]. The experiments were carried out in a static reactor at temperatures between 579 and 629 °C. Barnard suggested that, in the absence of oxygen, n-butanol primarily reacts by the fission of the molecule at the C3H7–CH2OH bond. This produces formaldehyde, ethylene and a methyl radical, following the decomposition of the n-propyl radical. Barnard also conducted a similar study of t-butanol[10]. A study by Roberts measured the burning velocities of n-butanol using schlieren photographs of the flames [11], and found that the maximum burning velocity of n-butanol is similar to that of isopropyl alcohol and isopentyl alcohol. A recent study by McEnally and Pfefferle [12] measured the temperature and species in an atmospheric-pressure coflowing laminar nonpremixed flames. The fuels consisted of methane doped with one of the four isomers of butanol.They claimed that unimolecular dissociation was dominant, not H-atom abstraction. For n-butanol,this consisted of C–C fissionfollowed by β scission of the resulting radicals. In the case of n-butanol,complex fission involving four-center elimination of water was estimated to account for only 1% of n-butanol decomposition. The most important measured species included ethylene (C2H4) and propene (C3H6). More recently, Yang and co-workers [13] studied laminar premixed flames fuelled by one of four isomers of butanol(including n-butanol). Their results identify combustion intermediates in the butanol flames, but do not provide concentration profiles. The qualitative data provided lends support to the aforementioned dissociation mechanism proposed by McEnally and Pfefferle [12].In this paper, we report new experimental data obtained in a jet stirred reactor (JSR) for the oxidation of n-butanol at a pressure of 10 atm and a range of equivalence ratios (0.5–2.0) and temperatures (800–1150 K). In addition, a chemical kinetic model of n-butanol is developed using the JSR experiments as validation data. Both experimental and kinetic insights are offered below.2. Experimental methodsThe JSR experimental setup used in this study has been described earlier [14] and [15]. The JSR consists of a small sphere of 4 cm diameter (39 cm3) made of fused silica (to minimize wall catalytic reactions), equipped with four nozzles of 1 mm i.d. for the admission of the gases which achieve stirring. The reactants were diluted by high-purity nitrogen (<50 ppm O2, <1000 ppm Ar, <5 ppm H2) and mixed at the entrance of the injectors. A high degree of dilution (0.1% volume of fuel) was used, reducing temperature gradients and heat release in the JSR. High-purity oxygen (99.995% pure) was used in these experiments. All the gases were preheated before injection to minimize temperature gradients inside the reactor. A regulated heating wire of ca. 1.5 kW maintained the temperature of the reactor at the desired working temperature. The n-butanol was sonically degassed before use. A Shimadzu LC10 AD VP pump with an on-line degasser (Shimadzu DGU-20 A3) was used to deliver the fuel to an atomizer–vaporizer assembly maintained at 200 °C. Good thermal homogeneity along the vertical axis of the reactor (gradients of ca. 1 K/cm) was observed for each experiment by thermo-couple (0.1 mm Pt–Pt/Rh (10%) located inside a thin-wall silica tube) measurements. The reacting mixtures were probe sampled by means of a fused silica low pressure sonic probe. The samples were analyzed online by FT-IR and off-line after collection and storage in 1 L Pyrex bulbs. Off-line analysis was done using gas chromatographs equipped with capillary columns (DB-624 and Carboplot-P7), a TCD (thermal conductivity detector), and an FID (flame ionization detector).The experiments were performed at steady state, at a constant mean residence time of 0.7 s and a constant pressure of 10 atm. The reactants were continually flowing in the reactor while the temperature of the gases inside the JSR was increased stepwise. A good repeatability was observed in the experiments and reasonable good carbon balance of 100 ± 15% was achieved.3. Computational methodsThe kinetic modeling was performed using the PSR computer code [16] that computes species concentrations from the net rate of production of each species by chemical reactions and the difference between the input and output flow rates of the species. These rates are computed from the kinetic reaction mechanism and the rate constants of the elementary reactions calculated at the experimental temperature.The reaction mechanism used here is based on a previously proposed oxidation mechanism [17], [18] and [19] for C1–C4 chemistry. Additional reactions have been added to represent thebutanol mechanism and are listed in Table 1. The oxidation of n-butanol proceeds via unimolecular initiation and hydrogen abstraction reactions. The fuel radical species formed are consumed via unimolecular decomposition (β-scission) and biomolecular reactions. Isomerization of radical species is also included in the proposed model. Table 2 presents the structure of species produced during the oxidation of n-butanol.The rate expression for new reactions derives from tabulations for alkanes and alcohols [18] and [19]. This mechanism, including references and thermochemical data, is available as Supplementary material to this article. The rate constants for reverse reactions are computed from the corresponding forward rate constants and the appropriate equilibrium constants, calculated from thermochemistry [20] and [21].Table 1. Reactions representing the oxidation of n-butanolFull-size tableNote: X denotes a radical species (OH, H, CH3, O, HCO, HO2, CH2OH, CH3O, C2H5, C2H4, C4H7, aC3H5).View Within ArticleaC4H8OHbC4H8OHcC4H8OHdC4H8OHcC3H6OHaC3H6OHFull-size tableView Within Article4. Results and discussionMolecular species concentration profiles were measured by sonic probe sampling and GC and FT-IR analyses from the oxidation of n-butanol in a JSR: hydrogen (H2), water (H2O), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), acetylene (C2H2), ethylene (C2H4), ethane (C2H6), propene (C3H6), 1-butene (C4H8), acetaldehyde (CH3HCO), formaldehyde (CH2O), butyraldehyde (C3H7CHO), and n-butanol(C4H9OH). Figure 1 presents the experimental measurements and modeling results of n-butanol obtained at = 1.0. Theexperimental results (solid symbols) show that with increasing temperature, the n-butanol levels drop significantly between 800 and 900 K. This corresponds to a large increase in the concentrations of butyraldehyde, 1-butene, and propene, all of which are products of H abstraction pathways. The concentration of these compounds then quickly decreases as the temperature increases. Ethylene, ethane, acetaldehyde, and formaldehyde concentrations are also shown to increase between 800 and 900 K. However, as the temperature increases further, the concentrations of these species tends to diminish at a slower rate than the aforementioned species.Full-size image (63K)Fig. 1. Comparison of the experimental concentration profiles obtained from the oxidation of n-butanol in a JSR at = 1, P = 10 atm, τ = 0.7 s.View Within ArticleThe following oxygenated products were detected: butanal, ethyloxirane, propanal, 2-propenal, methyloxirane, oxirane, and acetaldehyde. The oxiranes, 2-propenal, and propanal are formed at low ppm levels, and therefore no concentration profiles are reported. Enols were not detected. A comparison with results obtained for ethanol in similar conditions and keeping the initial carbon content shows butanol oxidation produces less aldehydes overall. The maximum amount ofacetaldehyde production is reduced by ca. 70% when changing the fuel from ethanol to butanol. The model predictions (open symbols with line) for = 1.0 are also shown in Fig. 1. Reasonablygood agreement is obtained for all measured species. The major product species (i.e., CO, CO2, and H2O) are well predicted by the model. Methane, ethylene, hydrogen, and formaldehyde are also reasonably well predicted across the entire temperature range. The reactivity of n-butanol is well predicted between 800 and 950 K, but at greater temperatures the reactivity is overpredicted. Species concentrations of butyraldehyde, 1-butene, and acetaldehyde are well predicted until approximately 1000 K, above which they become underpredicted. The propene concentration is underpredicted across the entire temperature range, while ethane and acetylene concentrations are overpredicted across the entire temperature range.Figure 2 presents the experimental measurements and modeling results of n-butanol obtained at = 0.5. For the most part, the experimental results show a similar trend to that observed at= 1.0. The concentration of n-butanol is lower at = 0.5 than at = 1.0 due to the fact that agreater oxygen concentration exists in the oxygen–fuel mixture. The model better predicts the concentration of most species at = 0.5 than it does at = 1.0. 1-Butene, propene, butyraldehyde,carbon monoxide, carbon dioxide, methane, ethylene, acetaldehyde, formaldehyde, water, and hydrogen are well predicted across the entire temperature range. Similar to the case of = 1.0, thereactivity of n-butanol is overpredicted above 900 K. Again, the concentrations of acetylene and ethane are overpredicted across the entire temperature range.Full-size image (64K)Fig. 2. Comparison of the experimental concentration profiles obtained from the oxidation of n-butanol in a JSR at = 0.5, P = 10 atm, τ = 0.7 s.View Within ArticleFigure 3 presents the experimental measurements and modeling results of n-butanol obtained at = 2.0. Similar trends as those observed for other equivalence ratios are observed for theexperimental data at = 2.0. At = 2.0, the reactivity of n-butanol is well predicted across theentire temperature range, something which was not observed at other equivalence ratios In addition, there is good prediction of carbon monoxide, carbon dioxide, methane, ethylene, acetaldehyde, ethane, formaldehyde, water, and hydrogen. Qualitatively, the prediction of acetylene concentration is satisfactory. The butyraldehyde concentration is well predicted below 1000 K, while above 1000 K the model underpredicts the experimental data. The concentration of 1-butene is overpredicted above 900 K, while the concentration of propene is under underpredicted across the entire temperature range.Full-size image (63K)Fig. 3. Comparison of the experimental concentration profiles obtained from the oxidation of n-butanol in a JSR at = 2, P = 10 atm, τ = 0.7 s.View Within ArticleSome general trends are observed via analysis of the data across the three equivalence ratios. The model’s prediction of carbon monoxide, carbon dioxide, methane, ethylene, for maldehyde, water, and hydrogen concentrations is reasonably accurate across all equivalence ratios. The prediction of n-butanol,acetaldehyde, and acetylene concentrations tends to improve with increasing equivalence ratio. On the other hand, an increase in equivalence ratios results in poorer prediction of 1-butene, propene, butyraldehyde, and ethane concentrations.A reaction pathway analysis was performed at = 1.0 at T = 1000 K to determine the mostdominant pathways for n-butanol consumption. Figure 4 presents the results of the analysis in diagram format, wherein heavier weight arrows represent more dominant reaction pathways. According to the proposed model, n-butanol is consumed primarily via H-atom abstraction from the α, β, and γ carbon atoms, with each pathway accounting for approximately 22% of the total n-butanol consumption. The next most dominant pathway is H-atom abstraction from the hydroxyl group, which accounts for nearly 20% of n-butanol consumption. H-atom from the δ carbon atom accounts for nearly 14% while all the unimolecular decomposition pathways combined account for less than 0.5% of n-butanol consumption. Similarly, a reaction pathway analysis at T = 1200 K showed that unimolecular decomposition accounted for less than 4% of n-butanol consumption. Therefore, it is reasonable to conclude that n-butanol consumption in the JSR is dominated by H-atom abstraction.Full-size image (16K)Fig. 4. Reaction pathway diagram for n-butanol oxidation in the JSR at = 1, P = 10 atm,τ = 0.7 s, T = 1000 K.View Within ArticleThe pathways diagram in Fig. 4 indicates that the aC4H8OH radical primarily undergoes β-scission to form acetaldehyde and an ethyl radical (C2H5). The consumption of the bC4H8OH radical is also consumed primarily by β-scission to form a hydroxyl radical and 1-butene. The cC4H8OH radical primarily undergoes β-scission to form propene and a hydroxymethyl radical(CH2OH). The hydroxymethyl radical, which is also an intermediate in several n-butanol unimolecular decomposition pathways, undergoes β-scission to create formaldehyde. The C4H9O radical, which is formed primarily via H-atom abstraction from the n-butanol hydroxyl group, undergoes β-scission to form butyraldehyde. The least prominent n-butanol H-atom abstraction pathway leads to the formation of the dC4H8OH radical, which isomerizes to form the aC4H8OH radical. The n-butanol unimolecular dissociation reactions proceed to form radical species, which then undergo β-scission to form stable species such as acetylene, ethylene, and formaldehyde, and a number of radical species.Sensitivity analyses were conducted for n-butanol,propene, and acetylene as these compounds were not always well predicted by the model. n-Butanol was underpredicted above 900 K at both = 1.0 and = 0.5. Figure 5a displays the normalized sensitivity coefficients for the top 12reactions to which the n-butanol concentration is sensitive at T = 1050 K and all equivalence ratios. A positive sensitivity coefficient implies that an incre ase in the reaction’s forward rate will increase the n-butanol concentration at the specified temperature and equivalence ratio. At all equivalence ratios, the n-butanol concentration is very sensitive to the reaction producing OH radicals via the oxidation of H radicals. At = 0.5, the n-butanol concentration is mainlysensitive to elementary reactions between hydrogen and oxygen containing species. However, at = 1.0 and = 2.0, the n-butanol concentration is more sensitive to reactions involvinghydrocarbon radical species. This is because the pool of hydrocarbon radicals becomes more predominant as the fuel concentration in the oxygen–fuel mixture increases. Of all the n-butanol consumption reactions, the n-butanol concentration is most sensitive to those involving H-abstraction by OH radicals from the α and γ carbons.Full-size image (44K)Fig. 5. Sensitivity of n-butanol and propene to select reactions in the JSR at P = 10 atm, τ = 0.7 s.View Within ArticlePropene concentrations were not well predicted at = 1.0 and = 2.0. Figure 5b displays thenormalized sensitivity coefficients for the top 11 reactions to which the propene concentration is sensitive at T = 1000 K and all equivalence ratios. The propene concentration is sensitive to elementary reactions between hydrogen and oxygen containing species, as well as reactions involving small molecular weight hydrocarbon species. In addition, the propene concentration is sensitive to n-butanol consumption reactions involving H-abstraction from the α, β, and γ carbons.A sensitivity analysis on acetylene (not in figure) indicated the acetylene concentration is sensitive to reactions involving the C2H3 radical, and to elementary reactions between hydrogen and oxygen containing species. Adjusting the reaction rates of n-butanol consumption reactions hadlittle effect on the concentration of acetylene.5. ConclusionsNew experimental data for n-butanol oxidation in a JSR at 10 atm and equivalence ratios between 0.5 and 2.0 are compared to a novel chemical kinetic model for n-butanol oxidation. The most abundant measured product species were carbon monoxide, carbon dioxide, water, hydrogen, methane, formaldehyde, ethylene, and propene. Measured in lesser amounts were butyraldehyde, 1-butene, acetaldehyde, ethane, and acetylene. The model proposed herein provides good overall agreement with the experimental data obtained across various temperatures and equivalence ratios. It is shown that H-abstraction is the major pathway of n-butanol consumption in the JSR, while unimolecular decomposition is relatively insignificant. Further model validations are still needed; they are awaiting the availability of ongoing flame measurements.AcknowledgmentThis research acknowledges funding from NSERC.References[1] D.T. Jones and D.R. Woods, Microbiol. Rev. 50 (4) (1986), pp. 484–524. View Record in Scopus | Cited By in Scopus (326)[2] T.C. Ezeji, N. Qureshi and H.P. Blaschek, Curr. Opin. Biotechnol. 18 (2007), pp. 220–227.Article | PDF (327 K) | View Record in Scopus | Cited By in Scopus (79)[3] D. Ramey, S. Yang, Production of Butyric Acid and Butanol from Biomass, Report No. DE-F-G02-00ER86106. US Department of Energy, Morgantown, Washington, 2004.[4] G. Hess, Chem. Eng. News 84 (26) (2006), p. 9. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (7)[5] G. Hess, Chem. Eng. News 85 (27) (2007), p. 8. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1)[6] Y. Yacoub, R. Bata and M. Gautam, Proc. Inst. Mech. Eng. 212 (1998), pp. 363–379. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (15)[7] G.L. Miller, J.L. Smith and J.P. Workman, Trans. ASAE 24 (1981), pp. 538–540.[8] T.K. Bhattacharya, S. Chatterjee and T.N. Mishra, Appl. Eng. Agric. 20 (3) (2004), pp. 253–257. View Record in Scopus | Cited By in Scopus (10)[9] J.A. Barnard, Trans. Faraday Soc. 53 (11) (1957), pp. 1423–1430. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (11)[10] J.A. Barnard, Trans. Faraday Soc. 55 (6) (1959), pp. 947–951. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (4)[11] A.F. Roberts, J. Imp. Coll. Chem. Eng. Soc. 12 (1959), pp. 58–73.[12] C.S. McEnally and L.D. Pfefferle, Proc. Combust. Inst. 30 (2005), pp. 1363–1370. Article |PDF (389 K) | View Record in Scopus | Cited By in Scopus (41)[13] B. Yang, P. Oswald and Y. Li et al., Combust. Flame 148 (2007), pp. 198–209. Article | PDF (1138 K) | View Record in Scopus | Cited By in Scopus (54)[14] P. Dagaut and M. Cathonnet, Prog. Energy Combust. Sci. 32 (2006), pp. 48–92. Article |PDF (1414 K) | View Record in Scopus | Cited By in Scopus (77)[15] P. Dagaut and S. Gail, J. Phys. Chem. A 111 (19) (2007), pp. 3992–4000. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (27)[16] P. Glarborg, R.J. Kee, J.F. Grcar, J.A. Miller, PSR: A FORTRAN Program for Modeling Well-Stirred Reactors, Report No. SAND86-8209, Sandia National Laboratories, Livermore, CA, 1986.[17] T. Le Cong, P. Dagaut, Kinetics of natural gas, natural gas/syngas mixtures oxidation and effect of burnt gas recirculation: experimental and detailed modeling, in: Proceedings of the ASME Turbo Expo 2007: Power for Land, Sea and Air, Montréal, Canada, May 14–17, 2007, GT2007-27146, pp. 1–9.[18] P. Dagaut, Phys. Chem. Chem. Phys. 4 (2002), pp. 2079–2094. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (100)[19] F. Battin-Leclerc, R. Bounaceur, G.M. Côme, et al., EXGAS-ALKANES, a software for the automatic generation of mechanisms for the oxidation of alkanes, 2004, CNRS-DCPR.[20] Y. Tan, P. Dagaut, M. Cathonnet and J.C. Boettner, Combust. Sci. Technol. 102 (1994), pp. 21–55. Full Text via CrossRef[21] C. Muller, V. Michel, G. Scacchi and G.M. Côme, J. Chim. Phys. Phys.-Chim. Biol. 92 (5) (1995), pp. 1154–1178.Appendix A. Supplementary dataDownload this File (85 K)Supplementary data. The proposed n-butanol chemical kinetic mechanism in CHEMKIN format View Within ArticleDownload this File (160 K)Supplementary data. The proposed n-butanol thermochemical data in CHEMKIN formatView Within ArticleDownload this File (515 K)Supplementary data. An MS Excel data file with all the experimental and model dataView Within ArticleCorresponding author. Fax: +1 416 978 7753.Proceedings of the Combustion InstituteV olume 32, Issue 1, 2009, Pages 229-237。

【免费下载】生物分离名词解释

Chapter 1Downstream processing(DSP)：The isolation and purification of a biotechnological product to a form suitable for its intended use. The separation and purification of products synthesized by bioprocesses:Biotechnology：the use of cultured microorganisms, animal cells, and plant cells to produce products useful to humans.Modern biotechnology：Built on genetic engineering to produce commercial products or processes.Chapter 2Coagulation：the chemical alteration of the colloidal particles to make them stick together凝聚值：表示电解质的凝聚能力，使胶粒发生凝聚作用的最小电解质浓度m mol/L. Flocculation: a process whereby particles are aggregated into clusters.Filtration separates solid from a liquid by forcing the liquid through a filter medium.滤浆（feed/ slurry）：悬浮液过滤介质(filter medium) ：多孔物质滤液(filtrate)：通过过滤介质的液体滤饼(filter cake)：被截留的固体物质Conventional or dead-end filtration: the fluid flows perpendicular to the medium which result in a cake of solids depositing on the filter medium.Crossflow filtration:The fluid flows parallel to the medium to minimize buildup to solids on the medium.Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures.分离因数（Z）：离心力与重力的比值。

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INTERNET-BASED PROCESS OPERATION:AN EDUCATIONAL APPROACHCarlos A. V. Junior, Cauê T.O.G. Costa, Ana M.C. Carreiro, Ofélia Q.F. Araújo*Escola de Química - Universidade Federal do Rio de JaneiroAbstract. The emerging Internet technologies offer unprecedented interconnection capability and ways ofdistributing collaborative work. Chemical engineering research will be impacted by IT in a number of ways,e.g., increased use of advanced computing to replace experimentation, access to digital libraries and use ofintelligent agents for literature searching, and the formation of networks of faculty, a virtual collaboratory(Edgar, 1999). Among all, process control shows evident benefits from IT. As information bridge speciallydeveloped for process control applications stands OPC. It allows connectivity of control hardware,supervisory control software for data acquisition and managing, man machine interface, data handling andvisualization software, etc. In the present work, MATLAB (Mathworks Inc) is employed as a central piecefor communication between the process control computer and remote users through the Internet, as well asdata mining. In this architecture, MATLAB transfers information to web-clients using IIS-Windows 2000Internet Server, and standard Internet browsers for data access. Such low-cost architecture transforms officePCs into remote interfaces to the real process. In addition, the web-clients can also receive real-time imagesfrom the process through low-cost web camera, as video interface is an important didactic resource forlearning tool. In this work, a web-based collaboratory in process operation is developed based on a bench-scale bioreactor, on-line process instrumentation, a software for supervisory control (FIX32). Data analysisand visualization (MATLAB) are distributed among intranet/internet-connected machines though OPC basedclient-server communication. The developed system uses ASP technology to generate forms that will serve asdata integration interface between web-client and real process. In conclusion, Internet promoted connectivityis unrivalled when it comes to process operation as it enables, for example, remote monitoring and adjustmentof plants; and collaboration between skilled plant managers situated in geographically diverse locations.Keywords: Web-based control, Process Control and Internet Technologies1. IntroductionInternet related technologies offer integration capabilities for education directed applications such as webminars, weblabs, among others. The web is no longer restricted to static pages where the user has an strictly contemplative role, and becomes a dynamic environment: personalized visualization resources, data transfer forms and interactive animations allows increased user interventions. Technologies such as ASP (Active Server Page), CGI (Common Gateway Interface), Java and Flash (Macromedia) are now available to explore this dynamic aspect. Nevertheless, the uses of such technologies are still rare in engineering education vis-à-vis to their educational benefits: experiments remote controlled through Internet technologies release geographical limits and the plant location looses its relevance, therefore promoting bridges for networked research and education.* To whom all correspondence should be addressed.Address: Escola de Química, UFRJ - Centro de Tecnologia, Bl.E, 21949-900 Rio de Janeiro – BrazilE-mail: ofelia@eq.ufrj.br2. Man-Machine-Interface for Internet-based ControlSchilling et al. (2002) developed a remotely controlled system for robot, accessed by a large number of users as part of a Virtual Laboratory. The Virtual Laboratory congregates 12 universities distributed in the US, Canada and Europe, while the system is physically located in the US and Europe. Bonastre et al. (2005) describe the implementation of a large scale water monitoring system. Data is received through GSM (Global System for Mobile communications) technology, and the conceived application involves mathematical processing and virtual sensors to be distributed and shared though the Internet.Supervisory control software (iFIX, LabView, etc) are being expanded towards remote access, integrating a plant to its corporation managing system. The inter-communication of these environment levels is crucial to the understanding of the complete production process, with consequent improvements on the process performance at both technical and managing levels.With the advancements in process control and automation, and, more recently, the consolidation of Information Technologies (IT), the role of am control engineer as well as the process operator have suffered dramatic changes. The later no longer plays the role of process control loop elements such as, opening and closing valves, and measuring process variables to becoming a process modification supervisor (Alty and Bergan, 1995). To fit into this new paradigm, operators need access to a new information level, which requires updated man-machine interfaces. The use of text boxes, graphics and colors offers the chance for improving operator performance (Alty and Bergan, 1995).The aerospace industry is perhaps the best example of dedication to developing efficient graphical interfaces (Sainthuile, 1999; Riley et al, 1999). In the past, the large data volume passed to a pilot required, besides a co-pilot, an engineer on board. At present, computer-based data processing sends to the pilot only abnormal operation information, freeing the pilot to the noble mission of safely flying.The central target in designing a internet-based man machine interface (iMMI), in an education application, is to allow critical analysis and fast understanding of the plant. On this ground, a web-based interface should not necessarily mimic the graphical screen of a conventional supervisory system, but should rather be its simplified version (Schilling et al, 2002). In spite of dynamic resources available, composition tools for developing web interfaces are more limited than those available for creating a control room supervisory system interface. To design the interface, one should bear in mind the limitations and particularities of such new media, not specific for process control environments and different tools should be combined: while forms and text boxes may be solved through ASP, animation resources require Flash or Java.2.1. Hierarchical Control Levels under a Web PerspectiveBesides technical limitations, the designer should be aware of other limitations such as time delay caused by the web information traffic, uncoordinated simultaneous access of multiple users and safety. The strategy VSPC – Virtual Supervision Parameter Control – adopted by Yang and Alty (2003), proposes a solution to approach time delays in process control applications via Internet. Such strategy only applies to operations where delay is not critical to system performance.The aforementioned limitation requires a local control system to be classified in hierarchical levels (Yang and Alty, 2003). A basic regulatory level deals with pressures, flow rates and temperatures. Its correct and continuous performance is critical to maintain safe plant operation. Above it, the monitoring and supervision level, where supervisory software is located, provides a process vision and not an equipment-oriented approach as opposed to the regulatory level. Last, the optimization level – with a global business vision, the inventories and interactions among production units – is fundamental to the efficient operation of the company but does not endanger operation safety. Any failure that could occur at this level does not interrupt plant operation, as opposed to prior levels. Internet, at principle, could be associated to any of these hierarchical levels but, in general, is not appropriate to the basic levels, which require fast responses, not compatible with Internet time delays. However, in academic applications, it may be advantageous to incorporate Internet to these basic levels. Nevertheless, Internet applications are not to substitute for classical supervisory systems, but i n stead, to complement them.In the VSPC strategy, the control loop is locally installed, while Internet acts whenever the user ask for changes in control parameters such as set-points and controller tuning (Yang and Alty, 2003). The new parameters remain active until a new set is required. Therefore, Internet delays do not affect system performance nor retard parameter modifications. Hence, VSPC operates in a safe manner.To deal with simultaneous access, a hierarchy should apply to users, who should hold different permissions and priorities (Yang and Alty, 2003).2.2. System SafetyThe advantages of Internet based control are undeniable: low cost integration of plant to strategic planing levels; academic research with simultaneous participation of scientists geographically distributed, education, etc. (Schilling et al, 2002). However, risks are brought about by Internet should systematically be identified and a safe architecture should be designed. The system should minimize attacks and be equipped with remote identification and authorization, as well as firewall to keep away eventual attacks. Communication failure is another risk potential and therefore, critical operations should be avoided to be performed via Internet.3. A Case StudyTo illustrate the methodology, a process for studying the growth of Saccharomyces cerevisiae under a batch operated process was employed. The experimental setup presents research interests for investigating stress responses to exogenous inputs such as electrical potential. On the other hand, the bench-scale process is applicable to control and process identification classes as the unit has on-line measurements under a supervisory control system.The bioreactor consists of a 4 liter cylindrical vessel, with mechanical agitation. Dissolved oxygen (OD-2000, Actron) is regulated through air intake (control valve CV-500B Hass Manufacturing Company) under PIDstrategy, configured in a supervisory control software (FIX32, GE). DO controller settings and set-point may be adjusted from the supervisory system. Besides the oxygen control loop, on-line monitoring is provided for: pH (PH-2000, Actron), redox potential (AR-2000, Actron) and culture absorbance (Spectronic 200, Bausch & Lomb). The absorbance, though a calibration curve allows reading of cell density. Process instrumentation is fed to a multi-loop controller (CD-600, SMAR) used for communication with the process control computer.In this work, the development of a web-based interface was pursued as an additional man-machine interface. The interface design aimed for simplicity, holding the minimum necessary information for process operation. Its main objective is to allow for remote tuning of the DO controller.To education applications, the use of web camera offers undeniable advantages and allows visual monitoring of reactors. Video images enhance interaction student-process, and remove the ultimate impression of participating of a video-game section instead of operating a real process. In the present application, a web camera was connected to a server to provide visual information of the process to remote clients. The architecture adopted distributed computer resources such that the video server was independent of the supervisor computer. The overall system was composed of an instrumented bioreactor, a process computer (running the supervisory control software), an Internet server and a video server. Web clients are allowed access to the system. In Fig.1, system’s architecture is presented.(A) (B)Fig. 1. Operation of Bioreactor. (A) Bench-scale Instrumented Process; (B) Network Architecture3.1 Internet-based Man Machine Interface (iMMI)Figure 2a displays the screen for Internet-based operation. It provides the same functions available to the local user, which employs the supervisory control software. In the right side, a static graphical representation of theprocess – a process flowsheet – is shown for educational purposes. During operation, this image can be replaced by a trend graph, shown in Fig. 2b.(A)(B)Fig.2: Web-based Interface. (A) Primary Screen. (B) Trend GraphThe interface allows for modifications on tuning parameters and set-point. As opposed to a classical web page, the site contents is regularly re-generated by the server and re-sent to the client. Automatically, at a preset frequency, the site is refreshed, providing the user with new process information. Alternatively, to deal with simultaneous accesses, should any system parameter be altered by any user, the page is immediately updated so that every user will have access to the new values.Images acquired by the web-cam is a third display option, which was coupled to a teleconference software – NetMeeting (/windows/netmeeting), available in Windows operation system. ActiveXwas employed to embody NetMeeting to the site architecture, therefore providing interactive resources such as chat, whiteboard and file transfer. The communication ensemble allows for enhanced interaction student-professor and student-student.3.2 Data ManagementMATLAB (The Mathwoks Inc) is the central manager of information transference. The iMMI starts a MATLAB application that establishes the connection between the browser and the supervisory system. ASP employs ActiveX to integrating functionalities of the various Windows applications to the web environment. Through the creation of ActiveX objects, MATLAB and NetMeeting functions are embodied into the site. The leading advantage of using ASP routines is that they run at the server level, therefore allowing update of versions at a unique location, easying the development effort and reducing the client machines tasks. The connection of the iMMI with MATLAB (installed in the server) is established through the following ActiveX command:set conn = Server.CreateObject("Matlab.Application")Once the connection is set, the function execute allows runing MATLAB commands though the interface.In this way, it is possible to request MATLAB to access the supervisory system database, and to transfer the necessary information, a two-way traffic resource. Figure 3 illustrates data management executed by MATLAB. In order to refresh the site information, a routine is run through VBScript, according to the following commands:<script language="VBScript">window.setTimeout "reload()",30000Sub reload()location.reload(True)end sub</script>Fig.3. Data Management SchemeM ATLAB Communication to Plant Instrumentation. In the proposed architecture, the most relevant MATLAB functions are establishing an OPC connection (OPC Foundation, 2005) and numerical data processing. It is worthnoting that, although MATLAB was launched as an academic software tool, many industries use it for prototyping and testing. The main drawback to use it in these industries is the reduced possibilities to connect it directly to the DCS/PLC and the plant. To fill this gap, IPCOS Belgium developed ISMC OPC for MATLAB (IPCOS, 2005). Once installed, this MATLAB add-in opens a communication channel through the command:hr=mxopc('open', 'matrikon.opc.dde', 'localhost')Following the establishment of the communication channel, reading (readstring) and writing (writestring) commands are used in a MATLAB application for a two-way transfer with the Supervisory Control software. The employed software version (FIX32) does not offer a native OPC technology but through DDE commands and OPC2DDE (Matrikon, 2005), this limitation was by-passed.4. ConclusionsThis work presents the architecture for internet-based operation aiming primarily at education applications. Data analysis and visualization (MATLAB) are distributed among intranet/internet-connected machines though OPC based client-server communication. The developed system uses ASP technology to generate forms that serve as data integration interface between web-client and real process. In conclusion, Internet promoted connectivity is unrivalled when it comes to process operation as it enables, for example, remote monitoring and adjustment of plants; and collaboration between skilled plant managers situated in geographically diverse locations.ReferencesAlty, J.L. Bergan, M. (1995). Multi-media Interfaces for Process Control: Matching Media to Tasks. Control Eng. Practice, 3(2), 241.Bonastre, A. Ors, R. Capella, J.V. Fabra, M.J., Peris M. (2005). In-line Chemical Analysis of Wastewater: Present and Future Trends. Trends in Analytical Chemistry, 24(2), 128.Carlson, M. (1999). Glucose repression in yeast. Current Opinion in Microbiology, 2(2), 202.Edgar, T. (1999). /computer/itc/intel/edgar/Missouri_july19-99.pdfInternet World Stats. IPCOS (2005). http://www.ipcos.be/products/generic/connectivity/opcformatlab.htmlMATRIKOM Inc. (2005). /OPC Foundation (2005). Riley, V. DeMers, B. Misiak, C. Schmalz, B. (1999). The Cockpit Control Language: a Pilot-Centered Avionics Interface.Air & Space Europe, 1(1), 48.Sainthuile, G.(1999). The Future Functionalities of the Flight Management System. Air & Space Europe, 1(1), 51. Schilling, K. Roth, H., Lieb R. (2002). Remote Control of a “Mars Rover” via Internet – To Support Education in Control and Teleoperations. Acta Astronáutica, 50(3), 173.Yang, S.H. Alty, J.L. (2003). Development of a Distributed Simulator for Control Experiments through the Internet. Future Generation Computer Systems, 18, 595.AcknowledgmentsThe authors gratefully acknowledges CNPq – Conselho Nacional de Desenvolvimento Científico for research grant and scholarships, and CAPES – Coordenação de Aperfeiçoamento de Pessoal de Nível Superior for scholarships.。