Non-isothermal Kinetics of Pyrolysis of Three Kinds of Fresh Biomass

The pyrolysis kinetics of three different kinds of fresh biomass （grass： triple A, wheat straw, corn straw） in nitrogen flow were studied by thermogravimetric analysis at five different heating rates. The kinetic parameters of the pyrolysis process were calculated using the method of Ozawa-Flynn-Wall and the mechanism of reactions were investigated using the method of Popescu. It was found that the values of activation energy varied in different temperature ranges. The pyrolysis processes are well described by the models of Zhuravlev （Zh） and valid for diffusion-controlled between 200 ℃ and 280 ℃, by Ginstling-Brounshtein （G-B）, valid for diffusion-control between 280 ℃ and 310 ℃, for first-order chemical reaction between 310℃ and 350 ℃. by Zhuravlev （Zh） valid for diffusion-control between 350 ℃ and 430 ℃ and by the one-way transport model when temperatures are over 430 ℃.     

Electrochemical determination of Gibbs free energy of formation of magnesium ferrite

The standard Gibbs free energy of formation of magnesium ferrite was determined by means of two types of solid state electrochemical cells: one using MgZr4(PO4)6 (MZP) as the solid electrolyte and the other using CaF2 as the solid electrolyte. The first cell was operated in the range of 950 to 1100 K. The second cell was operated in the range of 1125 to 1200 K. The reversibility of the cell EMFs was confirmed by microcoulometric titration. The Gibbs energy changes of magnesium ferrite relative to component oxides were calculated based on EMF measurements and are given by following expressions, respectively: △G(o)Ⅰ = -3579-15 T (J/mol) and △G(o)Ⅱ =6258-24.3 T (J/mol). The results obtained from two different cells are consistent with each other. The results also are in agreement with Rao's and Tretjakov's data in the measured temperature range. When the Gibbs free energies of formation of MgO and Fe2O3 were substituted in the reaction, the Gibbs free energies of formation of MgFe2O4 was obtained in two temperature ranges and the formations are shown as follows: △G(o)Ⅰ Formation = -1427394 360.5 T (J/mol) and △G(o)Ⅱ Formation = -1417557 351.2 T (J/mol).     

Influence of Lithological Characters of Coal Bearing Formation on Stability of Roof of Coal Seams

Lithology is one of the important factors influencing the stability of roof of coal seams. In order to investigate this, the phenomenon of underground pressure and distribution of pressure were studied by using the local observation and simulation test with similar materials. The observation results show that the distance of initial weighting and periodic weighting of the mudstone roof is shorter than that of sandstone roofs. The sandstone roof with a high strength has a longer distance of initial weighting and periodic weighting, the abutment stress on the working face is big and the height of caving and fracture zone is high. The peak point of abutment stress in the sandstone roof is near to the working face and the pressure bump is inclined to occur. The result is contrary to that in case of the mudstone roof with a low strength. While in the transition zone of nipped sandstone, roof rock-mass is broken and is poor in stability, therefore, it is difficult to hold the roof.     

Effects of synthetic conditions of pulse galvanostatic method on electroactivity of polyaniline

1　INTRODUCTIONConducting polymers, due to their potentialapplication prospects, have been investigated ex tensively during the past decade[1 10]. Conductingpolyaniline (PANI), on account of its excellent op tical and electronic properties, is promising inmany fields, such as electronic devices, electro chromic devices, and ion switching devices[11 16].The morphology of conductive PANI can varygreatly with the preparation methods and condi tions. Gene…     

Journal of Huaihai Institute of Technology General Table of Contents,2002

Vol.1 1　No.1　 ( Sum No.36)The Generalized Degree for Multi- valued Compact Perturbations of m- accretive Operators　　 L I Yu- qiang,L IU L i- wei(1)……………………………………………………………………………………………………A Hybrid Algorithm for the Optimization of Multi- peak Continuous Function XU Shi- gang,ZHAO Shu- yu(5 )……………A Study on the Design of L ong and Thin Metal's Bending Machine YOU Zhuan(8)…………………………………………Design Methods of Fast Ethernet…     

Mechanism of reaction synthesis of Li-B alloys

Li-B alloy[1] has greater specific capacity, more negative potential and greater specific power than the well-known anode materials of thermal battery[24]. As a promising anode material for the thermal battery, the Li-B alloy is in nature a composite that consists of porous and refractory Li-B compound frame and metal Li filled in the porosity. That is why it can be kept in solid state at above 600℃, with the electrochemical properties very similar to those of pure Li. Though its applicati…     

Evaluation of Security of Mine Ventilation Systems

A mine ventilation system has a deterministic function for the ~fety of coal production and for the control of mine accidents. So, it has an important meaning to evaluate the security of a mine ventilation system. This paper studied the evaluation index system of the security of a mine ventilation system, and the security of a mine ventilation system was dc,described quantitatively in the safety degree. Finally, an example of the seurity evaluation was given.     

Product of spaces of doubly periodic arrays

A characterization of the space generated by the Hadamard product of doubly periodic arrays is presented, and the results of Zierler and Mills are extended to higher dimensions.     

Application of photobioreactors to cultivation of microalgae

0　INTRODUCTIONHighcelldensityandindustrialproductionofmi croalgaecanberealizedbyphotobioreactorswhichprovidenecessaryconditionsformicroalgaecellbreedingandvalu ablesubstanceaccumulation .Mostmicroalgaearephotoautotrophy ,sothecultureprocesscanbeaccomplishedinaphotobioreactor.Inor dertorealizehighcelldensitycultureofmicroalgae ,manyfactorsmustbeconsideredwhileaphotobioreactorisde signed :First ,highratiooflightsurfaceareaandvolumeforincreasinglightutilizationratioofmicroalgae .Second ,app…     

Journal of Central South University of Technology

1 Aims and scope Central South University (CSU) is one of Chinese key universities, which is affiliated with the Ministry of Education. "Journal of Central South University of Technology" (ISSN 1005-9784, CODEN JCSTFT) is sponsored by CSU.     

Two Classes of Models of Granular Computing

1 Introduction Basic ideasand methods of granularcomputing have been employed to problem solvingin many ap- plied fieldsfor a long time.In granularcomputing one usesgroups ofelements (calledgranules)instead of individualelements.Main reasonsfornecessityof…     

Optimal Control of Aeroelastic StochasticVibration of Aerocraft

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Iteration of the Composition of Entire Functions

Let P(x) be entire and g(x) = λe^x, λ∈C- {0｝. If f= P(g) has no wandering domain, then nei-ther does h = g(P). The normal sets of h = g(P) and f= P(g) have no Baker domain at the same time.     

Mechanism of influence of chloride ions on electrogenerative leaching of sulfide minerals

1 INTRODUCTIONElectrogenerative leaching process is a newtechnique in hydrometallurgy .ZHANG et al[1]in-troduced the principle and technique of electrogen-erative process to metallurgy field by the leachingof synthetic Ni3S2with FeCl3.In order to utilizethe chemical energy in leaching process reasonablyand si mplify the purifying process , Wang et al[2 8]studied the electrogenerative leaching of a series ofsulfide minerals through a dual cell system withFeCl3and acidic MnO2as oxidant…     

Preparation of Nanometric Particles of Aluminum Nitride by Pyrolysis of Diethylaluminun Azide

Thermal stabilities of diethylaluminum azide were studied by means of theoretical analysis and expriments.The results have shown that diethylaluminum and azid be heated to vigorous refluxing under vacuum(400 Pa) at temperature as high as 420℃ without incident of explosion and decomposes smoothly during 460 ～580℃ to form nanometric particles of aluminum nitride in the aerosol synthesis reactor. A new way of preparing nanometric parties of aluminum nitrideis found.     

Influence of austenitizing temperature on apparent morphologies of as-quenched microstructures of steels

1 INTRODUCTIONZackey et al[1]found that high austenitizingtemperatures can suppress plate martensite forma-tion,and canincrease the amount of lath martens-ite in structural steels ,and further suggested thatthe toughness of steels may bei mproved by raisingthe quenching temperature . Up to now, many re-searchers have studied the influence of hardeningtechnologies on martensitic morphologies andproperties , and have drawn the same conclusionthat the amount of lath martensite may be in-creas…     

Simulation of response of sodium layer to the propagation of gravity wave

Thegravitywaveisoneofthemostimportantphenomenaofatmosphericwaves.Owingtotheexponentialdecreaseintheatmosphericdensity,theamplitudeofgravitywaveincreasesasitpropagatesfromloweraltitudetohigheraltitude.Whenthegravitywavereachesmesopauseregion,insomecases,thegravitywavebreaksandproducesturbulence.Therefore,thegravitywaveisoneofthemostimportantatmosphericwaves.Thesodiumlayer,whichislocatedintheregionbetweenabout80kmtomorethan100km,isoftendisturbedbygravitywaveswhichpropagatefromlowerpartofatmosphe…