Preparation of ZrO2 nano-particles by the hydrolysis of ZrOCl2 solution in the reverse micelles

Zirconia nano-particles have been produced by the hydrolysis of ZrOCl2 solution in the reverse micelles of a liquid-liquid two-phase system, in which sodium bis（2-ethylhexyl） sulfosuccinite （AOT） and toluene were chosen as the surfactant and organic phase, respectively. The reverse micelles prevented the aggregation of primary particles and reduced the diameters of zirconia nanoparticles. Superfine zirconia powders soft-aggregated by the zirconia nano-particles were obtained. The diameters of zirconia nanoparticles were influenced by the quantity of the surfactant.     

Reliability of paste fill system of the Jinchuan No.2mine

Bacause of poor ground conditions,stoping methods of underhand headings with cemented fill were used in the Jinchuan No.2 mine,a paste fill system was set up.In order to evaluate the reliability of the new system,investigations and trial running have been done,More than 20 items of modification or improvements related to paste preparation subsystem,pump and pipe subsystem,auto-controlling and monitoring subsystem were finished.The reliability of the paste fill system was analyzed by using the theory of large complex system,and it is useful in reliability study on paste fill system.     

Effect of Electron Beam on the Structure and Crystallization Features of BaO-SrO-TiO_2-SiO_2 Glass

Glasses of BaO-SrO-TiO2-SiO2 after electronic radiation treatment of 50 - 1000 kgy were studied by means of IR spectra, DTA and visible light absorption method. The result shows that the glass structure is changed due to the formation of structure defect from oxygen vacancy and E' color center, which resultsd in the crystallization process and new precursors, and decreasement of Tg temperature and crystallization peaks by 20 -50℃.     

Effect of Electron Beam on the Structure and Crystallization Features of BaO-SrO-TiO2-SiO2 Glass

Glasses of BaO-SrO-TiO2-SiO2 after electronic radiation treatment of 50-1000 kgy were studied by means of IR spectra, DTA and visible light absorption method. The result shows that the glass structure is changed due to the formation of structue defect from oxygen vacancy and E‘color center, which resultsd in the crystallization process and new precursors, and decreasement of Tg temperature and crystallization peaks by 20 -50℃.     

Laser oscillation of the lowest triplet-triplet transition in_2

The laser oscillation of the lowest triplet-triplet transition in Na2 is reported for the first time and its kinetic process is tentatively discussed.     

Theoretical Analysis of the Effect of Mediator on the Reaction of the Enzyme Electrode

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Effect of La Dopant on the Structure and Electrochemical Properties of LiCoO_2

1Introduction AgreatdealofdevelopmenthasbeenmadeforLi ionsecondarybatterysinceitwasinventedin1990[1].As apartofpowersources,thecathodeplaysacriticalrole foritsproperties.Lithiatedtransitionmetaloxidessuchas LiCoO2,LiMn2O4andLiNiO2areusuallyusedascathode m…     

Influence of TiO_2 on the Alkali Resistance and Structure of Invert Glass

1　IntroductionTheinvertglassisakindofglasswhosenumberofbridgeoxygenyisnotbiggerthan 3.WhenthereisonlyoneglassformerSiO2 ,itsmolarcontentisnomorethan66 .7% .Onthisoccasion ,theglassstructuremaychangefromthree dimensionalconsecutivenetworktolaminarnetwork (y =3) ,chainstructure (y =2 ) ,andislandstructure (y =0 ) [1].TheinfluenceofTiO2 onthealkaliresistanceandstructureintheinvertglasshasnotbeenreported .Thispaperwilldiscussitindetail.2　ExperimentalThematerialsusedwerechemicalpureSiO2 ,TiO…     

Effect of La Dopant on the Structure and Electrochemical Properties of LiCoO2

The cathode material LiCo1-xLaxO2（x=0,0.01,0.02,0.05）for Li-ion battery was prepared in solid phase,Effects of La dopant on the structure were analyzed by X-ray diffraction.and the morphology of the samples was observed by scanning electron microscopy.The results show that the structure of LiCoO2 becomes more and more non-perfect with the4 increasing comtent of La and some impurity peaks appear in the XRD pattern when the La content reaches 0.05.Meamchile,a high synthesis temperature is advantageous to the intact and unitary compound,The initial discharge capacity of doped material containing La（x=0.01）synthesized at 900℃ reaches 160 mAh/g by charge-discharge test.which prior to that of non-doped material synthesized under the same condition.However,the increasing La content deteriorates the cycling performance.Therefore,the appropriate content of La is 0.01 and the optimum synthesis temperature is 900℃.     

Effect of the Cool System on Internal Stress of CaO-Al_2O_3-SiO_2 Glass-ceramic System

The samples were attained through altering the cooling system of producing glass-ceramics. The X-ray diffraction was used to test the stress value of different samples.The relation of the cooling system and internal stress were also investigated.The experimental results show that the stress of glass-ceramic had a close relation with starting cool temperature.Above 800℃,glass-ceramic could be accelerated cooling and did not bring stress.Temperature between 500℃and 800℃was an important temperature range of the formation of stress in glass-ceramic,in which the glass-ceramic stress would change obviously.Cool system was the key on how to control and eliminate internal stress in order to reduce the destroy of materials crated by internal stress.In addition,glass particles size increase,glass-ceramic stress increase in consequent.     

Numerical Simulation of the Temperature Field in Sintering of TiB2-BN by SPS

1 IntroductionWiththe extensive application of the Spark PlasmaSintering (SPS) method,people have gained deeper un-derstanding of it .SPSis capable of sintering various con-ductors as well as insulation materials rapidly, both ofwhich have a high degree of density after being SPS sin-tered. Yet the mechanismof sintering conductors differsfromthat of sinteringinsulation materials inthe enormousdistinctionsinthe heating-up patterns and contraction dis-placement fromsintering[1].Different ph…     

Initial corrosion behaviors of AZ91 magnesium alloy in the presence of SO2

The effects of SO2 on the initial atmospheric corrosion of AZ91D magnesium alloy were investigated in laboratory. Met-allographic observation, SEM (Scanning Electron Microscopy), XRD (X-ray Diffraction) and XPS (X-ray Proton Spectrograph) were used to analyze and discuss the initial surface morphology of corrosion layers and corrosion products. The corrosion rate of the alloy increases with increasing the content of SO2. The initial attack has the characteristics of localized corrosion and preferentially concentrates on a phase. MgO and Mg(OH)2 form at first, which provide a protective layer, then the existence of SO2 decreases the pH of the thin solution on the alloy, accelerates dissolution process, and promotes the formation of MgSO3·6H2O and MgSO4·6H2O, meanwhile cracks were found on the corrosion products with corrosion continuation. These soluble corrosion products and the cracks provide the paths for filtering oxygen and corrosion pollutants into the matrix, which results in severe localized co     

Microstructure and Thermal Properties of the GeS2-In2S3-CsI Glasses

The-homogeneous GeS2-In2 S3-CsI glassy samples were prepared by conventional melt-quenching method. When the molar ratio of In2 S3 to Csl remains 1, the non-crystalline region can extend to the composition 0.4GeS2-0.3In2S3-0.3 CsI. And with the addition of CsI, the glass-forming ability of this serial glass reaches its maximum at the composition 0.8GeS2-0.1 In2 S3 -0.1CsI. According to the Raman spectra, the microstructure of these glasses is mainly constituted by [ GeS4 ] and [ InS4-xIx ] tetrahedra, which are interconnected by the bridging sulfur atoms ; meanwhile, the ethane-liked structural units [ S3 Ge-GeS3 ] can be formed because of the lacking of sulfur ; Cs ^＋ ion, which is added from CsI , exists as the nearest neighbor of I-ion in the glassy network.     

Effect of Rare Earth Oxides on the Microstructure and Microwave Dielectric Properties of CaO-MgO-Nb2Os-TiO2 System Ceramics

La2O3 and SrO-doped CaO-MgO-Nb2O3-TiO2 system ceramics were prepared by solid-state ceramic technique.The microstructure and microwave dielectric properties of CaO-MgO-Nb2O5-TiO2-La2O3 cermics can be adjusted by varying the amount of La^3＋ or Sr^2＋ ions respectively.The replacement of Ca^2＋ by La^3＋ at A-site of the ceramics increases the quality factor Q value（ at 7.6GHz）as well as the temperature coefficient of resonant frequency τf and decreases the dielectric constant εr and the substitution of Sr^2＋ at A-site in this ceramics system exhibits opposite characteristics.The microwave properties of La^3＋,Sr^2＋-doped CaO-MgO-Nb2O5-TiO2 system ceramics depend on the degree of octahedral distortion inside materials.     

Investigation on the thermal decomposition of aged La2O3

The thermal decomposition process of air-aged La203 in argon atmosphere was studied using nonisothermal TG-DSC. X-ray diffraction and TG-DSC analysis showed that the aged powder was composed of La（OH）3 with small amounts of oxycarbonate. The decomposition process of air-aged La2O3 involves the two-step decomposition of La（OH）3 and the decomposition of oxycarbonate. The kinetic analysis of the two-step decomposition of La（OH）3 was carried out using Coats-Redfern and isoconversion （Ozawa） methods. The kinetics of the two-step decomposition can be described in terms of the nucleation and growth model A （m=1.5, m is the model parameter） and A （m=2.5）, respectively. The apparent activation energy for the first step is 136-144 （Coats-Redfern） and 137-164 kJ/mol （isoconversion）. The apparent activation energy for the second step is 191-194 （Coats-Redfern） and 186-213 kJ/mol （isoconversion）.     

Effect of Nb on the Mechanical Properties of Ti／Al2O3 Composite

1　IntroductionMetallic Titanium and alloy are necessary to theaerospace materials because they have excellent propertiesof low density, high strength, and resistance to high tem perature and erosion. And alumina has fine properties ofcalorifics, m…     

The Characteristics of the Surface Topography of Excimer Laser Processed Al2O3 Ceramic

Surface of Al2O3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of thesystem(MEMS). It is indicated that the statistic pararueters of surface topography processed by the excimer laser have an obvioas regularity. The arithmeticmean value Ro and the root-mean square value Rq change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them. A simplified nuuIel is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore, the surfaces processed by excimer laser are greatly fiat. Skewness root-mean-square value Zq changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.     

Effect of the Cool System on Internal Stress of CaO-Al203-SiO2 Glass-ceramic System

The samples were attained through altering the cooling system of producing glass-ceramics. The X-ray diffraction was used to test the stress value of different samples. The relation of the cooling system and internal stress were also investigated. The experimental results show that the stress of glass-ceramic had a close relation with starting cool temperature. Above 800 ~C, glass-ceramic could be accelerated cooling and did not bring stress. Temperature between 500 ℃ and 800℃ was an important temperature range of the formation of stress in glass-ceramic, in which the glass-ceramic stress would change obviously. Cool system was the key on how to control and eliminate internal stress in order to reduce the destroy of materials crated by internal stress. In addition, glass particles size increase, glass-ceramic stress increase in consequent.     

Effects of NaNbO_3-Co_2O_3 Co-additive on the Properties of PZN-PZT Ceramics

NaNbO_3-Co_2O_3 co-added PZN-PZT(PZCNNT)ceramics were prepared using conventional solid state reaction.The piezoelectric and dielectric properties were measured.The experimental results show that the addition of 0.3mol% Co_2O_3 leads to low dielectric loss(tgδ)in PZCNNT ceramics and the proper addition of NaNbO_3 not only improves piezoelectric properties but also decreases intensively dielectric loss and mechanical loss.The optimal ceramic having d_(33)=310 pC/N,k_p=0.59,ε_r=985,tgδ=0.0034,Q_m=1380 was obtained.