Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, t...Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, the process, weld combinations, laser-CMT hybrid welding and applications of CMT welding are critically reviewed. Microstructure and other weld characteristics have been discussed at length for various base metal combinations. Particularly, the welding of aluminium and steel with better results has been possible with CMT Welding. The results reviewed in this article indicate that the CMT-Laser hybrid welding is more preferable to Laser or Laser hybrid welding. CMT welding has found applications in automobile industries, defence sectors and power plants as a method of additive manufacturing.展开更多
1.Introduction Artificial intelligence(AI)is a rapidly growing field of technol-ogy,which“will enliven inert objects,much as electricity did more than a century ago.Everything that we formerly electrified will now co...1.Introduction Artificial intelligence(AI)is a rapidly growing field of technol-ogy,which“will enliven inert objects,much as electricity did more than a century ago.Everything that we formerly electrified will now cognitize”[1].AI advances are constantly pushing the frontier of what machines can do.Increased attention is being placed on AI research,as well as its development and deployment by commer-cial investors,defense strategists,and policy makers[2].展开更多
In this work, a simulated aircraft fuel tank inerting system has been successfully estab- lished based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the...In this work, a simulated aircraft fuel tank inerting system has been successfully estab- lished based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the inerting effectiveness of the system, including flow rate of the inert gas （nitrogen-enriched air）, inert gas concentration, fuel load of the tank and different inerting approaches. The experimental results show that under the same operating conditions, the time span of a complete inerting process decreased as the flow rate of inert gas was increased; the time span using the inert gas with 5% oxygen concentration was much longer than that using pure nitrogen; when the fuel tank was inerted using the ullage washing approach, the time span increased as the fuel load was decreased; the ullage washing approach showed the best inerting performance when the time span of a complete inerting process was the evaluation criterion, but when the decrease of dissolved oxygen concentration in the fuel was also considered to characterize the inerting effective- ness, the approach of ullage washing and fuel scrubbing at the same time was the most effective.展开更多
Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generati...Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.展开更多
To clearly elucidate the oxidative roasting behaviors of the bastnaesite, the thermal decomposition and oxidation of the bastnaesite concentrate in inert and oxidative atmosphere have been investigated in detail. Expe...To clearly elucidate the oxidative roasting behaviors of the bastnaesite, the thermal decomposition and oxidation of the bastnaesite concentrate in inert and oxidative atmosphere have been investigated in detail. Experimental data indicated that the initial decomposition temperature of the concentrate under N2 atmosphere is 150 ℃ higher than that under O2 atmosphere,most likely because the oxidation of the cerium induces the decomposition of the concentrate. For the roasted samples under N2 atmosphere at500 ℃ and above,the oxidation efficiency of the cerium is 19.8%-26.8% because of the fact that rareearth fluorocarbonate is first decomposed to form rare-earth oxyfluoride and CO2, and the cerium oxyfluoride is then partially oxidized by the CO2 gas. The rest cerium in these samples can be further oxidized in air at room temperature, with the oxidation efficiency of the cerium gradually increasing to above 80% in 7 d. This can be attributed to the obvious changes in the inner morphology of the roasted samples under N2 atmosphere at high temperatures, which largely induce the diffusion of the air and improves the oxidation activity of CeOF, and further induces the oxidation of CeOF by the air. XRD and XPS techniques were used to further verify the significant differences in the thermal decomposition behaviors of the bastnaesite concentrate under N2 and O2 atmosphere. Moreover, no oxidation of Pr^（3＋） to Pr^（4＋） in the roasted samples under both N2 and O2 atmosphere is observed. This gives an overall understanding of the oxidative roasting of the bastnaesite concentrate without additives.展开更多
Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and ...Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. So with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water(SCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20—70℃ proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid.展开更多
Decomposition of hydroxylammonium nitrate (HAN) solution with electrolytic decomposition method has attracted much attention in recent years due to its efficiencies and practicability.However,the phenomenon has not be...Decomposition of hydroxylammonium nitrate (HAN) solution with electrolytic decomposition method has attracted much attention in recent years due to its efficiencies and practicability.However,the phenomenon has not been well-studied till now. By utilizing mathematical model currently available,the effect of water content and power used for decomposition was studied. Experiment data shows that sacrificial material such as copper or aluminum outperforms inert electrodes in the decomposition of HAN solution. In the case of using copper wire to electrolyse HAN solutions, approximately 10 seconds is required to reach 100℃ regardless of concentration of HAN. In tem of power consumption,100W-300W was found to be the range in which decomposition could be triggered effectively using copper wire as electrodes.展开更多
Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness t...Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone （HAZ） increases and grains in the fusion zone （FZ） coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175℃ for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.展开更多
Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within th...Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within this field. Molten salt CO_2 capture and electrochemical transformation(MSCC-ET) process is a desirable method due to a high CO_2 solubility, a wide potential window of molten salts and easily-controlled electrode reactions. Generally, electro-splitting CO_2 in molten salts begins with CO_2 absorption reactions to form CO_3^(2-), which is then followed by the carbon deposition at the cathode and O_2 evolution at the anode. As a result, CO_2 is electro-converted to O_2 and carbon with different morphologies, compositions, microstructures and functional properties. This report introduces the MSCC-ET process, summarizes the reactions occurring in the molten salts and at the electrode surfaces, as well as the morphological variations of the cathodic products. The inert anode materials, cost estimation and scale-up evaluation of the process are then discussed. It is presumed that with a comprehensive understanding of the electrode reactions during electrolysis and the functional properties of carbon materials obtained during CO_2 electro-splitting can provide a foundation for further developing this environmentally friendly process.展开更多
LiFePO4/C was synthesized by high temperature solid-state method with cheap Fe2O3, LiH2PO4 and glucose as raw materials in absence of inert gas. The sample had ordered olivine-type structure other impurities character...LiFePO4/C was synthesized by high temperature solid-state method with cheap Fe2O3, LiH2PO4 and glucose as raw materials in absence of inert gas. The sample had ordered olivine-type structure other impurities characterized by the test of X-ray diffraction （XRD）. The charge-discharge test showed the sample could demonstrate 120.5 mAh/g at 0.2C rate with good cyclic capability. The powder microeleetrode cyclic voltammetry test indicated that the redox process of the sample had good reversibility.展开更多
In order to study the welding process,microstructure and properties of Al-Mg-Mn-Sc-Zr alloy,comparative methods of friction stir welding（FSW） and tungsten inert gas（TIG） were applied to the two conditions of this ...In order to study the welding process,microstructure and properties of Al-Mg-Mn-Sc-Zr alloy,comparative methods of friction stir welding（FSW） and tungsten inert gas（TIG） were applied to the two conditions of this alloy,namely hot rolled plate and cold rolled-annealed plate.The relationships between microstructures and properties of the welded joints were investigated by means of optical microscopy and transmission electron microscopy.Compared with the base metal,the strength of FSW and TIG welded joints decreased,and the FSW welding coefficients were higher than the TIG welding coefficients.The loss of substructure strengthening and a very little loss of precipitation strengthening of Al3（Sc,Zr） cause the decreased strength of FSW welded joint.But for the TIG welded joint,the disappearance of both the strain hardening and most precipitation strengthening effect of Al3（Sc,Zr） particles contributed to its softening.At the same time,the grains in weld nugget zone of FSW welded joints were finer than those in the molten zone of TIG welded joints.展开更多
ZnFe 2O 4 and ZnFe 2O 4 based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni 2O 3...ZnFe 2O 4 and ZnFe 2O 4 based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni 2O 3 CuO, Cu, ZnO and CeO 2 would increase the electrical conductivity, and the ZnFe 2O 4 based anodes with these additives were of good corrosion resistance. The current density on anode, the mole ratio of NaF/AlF 3 (MR) and the content of alumina in the bath effect the anode corrosion rate in different way.展开更多
The dissimilar joints of AZ61 and ZK60 magnesium alloys were obtained by tungsten inert gas arc(TIG)welding and activating tungsten inert gas arc(A-TIG)welding processes.Microstructure characterization shows that,the ...The dissimilar joints of AZ61 and ZK60 magnesium alloys were obtained by tungsten inert gas arc(TIG)welding and activating tungsten inert gas arc(A-TIG)welding processes.Microstructure characterization shows that,the fineα-Mg equiaxed dendrite crystals contained Mg17Al12 and MgZn2 particles in the fusion zone.The average size of theα-Mg grains in the fusion zone was refined to 19μm at welding current of 80 A,which resulted in the largest tensile strength of 207 MPa.The tensile strength and the width of the beam of the A-TIG welded AZ61/ZK60 joints showed strong dependence on the amount of TiO2.However,the inhomogeneity of the heat-affected zone near different base metals presented no significant effect on the mechanical properties of the welded joint.展开更多
Metal powders of superlative quality, i.e. high cleanliness, rapidly solidified and spherical shape, have seen an increasing demand in the market. The leading technology for the production of such powders is the inert...Metal powders of superlative quality, i.e. high cleanliness, rapidly solidified and spherical shape, have seen an increasing demand in the market. The leading technology for the production of such powders is the inert gas atomization of metal alloy melts. To fulfill these requirements, the metal alloy is usually produced in a vacuum induction melting furnace (VI-GA = vacuum induction melting/gas atomization) and poured by means of a preheated tundish system into a gas nozzle where the metal stream is disintegrated by a high kinetic energy inert gas jet. The produced micro-droplets solidify in a free fall inside the atomization tower. For special applications, super-clean and ceramic-free metal powders can be produced by using the EIGA (electrode induction melting/gas atomization) melting- and atomizing system. As an alternative to the metal powder route, the sprayforming technology allows to produce semi-finished products in one step. In this case, the metal droplets produced by the high-energy inert gas nozzle system are directly solidified on a substrate, allowing to form billets, rolls and tubes.展开更多
17（Cu-10Ni）-（NiFe2O4-10NiO） cermets were prepared by cold pressing and sintering in nitrogen atmosphere, and tested as inert anode for aluminum electrolysis at 960 °C for 10 and 40 h, respectively. Microstruc...17（Cu-10Ni）-（NiFe2O4-10NiO） cermets were prepared by cold pressing and sintering in nitrogen atmosphere, and tested as inert anode for aluminum electrolysis at 960 °C for 10 and 40 h, respectively. Microstructures and phase compositions of the as-sintered and post-electrolyzed samples were investigated. The impurity contents in the electrolyte and the cathode metal were detected in order to investigate the corrosion characteristic of the elements of Fe, Ni and Cu in the anode. A dense NiFe2O4 layer was observed on the surface of anode and thickened with prolonging the electrolysis time. In the newly formed dense ceramic layer, NiO phase disappeared as a result of being swallowed by NiFe2O4 phase, and the metal phase was oxidized during the electrolysis in which Cu element showed a higher dissolution rate than Fe and Ni elements. The formation process of the dense ceramic layer during the electrolysis was presented and explained by using the corrosion mode of the metal phase and the transformation mechanism from NiO phase to NiFe2O4 phase.展开更多
建立气相色谱法测定氟苯尼考中二乙胺和三乙胺残留的方法。采用Inert Cap for Amines毛细管胺类测试柱,经惰性处理的衬管,载气为氮气,流速3.0 mL/min,分流比为5∶1,检测器为FID。结果表明:该方法中二乙胺、三乙胺与其相邻峰完全分离;对...建立气相色谱法测定氟苯尼考中二乙胺和三乙胺残留的方法。采用Inert Cap for Amines毛细管胺类测试柱,经惰性处理的衬管,载气为氮气,流速3.0 mL/min,分流比为5∶1,检测器为FID。结果表明:该方法中二乙胺、三乙胺与其相邻峰完全分离;对照峰面积RSD均小于2%;二乙胺的检测限浓度为1.84μg/mL,定量限浓度为3.67μg/mL,在3.67~13.76μg/mL浓度范围内线性相关系数r为0.995 9;三乙胺的检测限浓度为0.50μg/mL,定量限浓度为1.50μg/mL,在1.50~374.63μg/mL浓度范围内线性相关系数r为0.998 6;二乙胺的回收率90.7%~103.0%,三乙胺的回收率90.8%~97.3%;小幅改变色谱条件,耐用性良好。方法操作简单、准确度高、重复性好,适用于氟苯尼考中二乙胺、三乙胺残留的测定。展开更多
文摘Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, the process, weld combinations, laser-CMT hybrid welding and applications of CMT welding are critically reviewed. Microstructure and other weld characteristics have been discussed at length for various base metal combinations. Particularly, the welding of aluminium and steel with better results has been possible with CMT Welding. The results reviewed in this article indicate that the CMT-Laser hybrid welding is more preferable to Laser or Laser hybrid welding. CMT welding has found applications in automobile industries, defence sectors and power plants as a method of additive manufacturing.
基金supported in part by the Shanghai Municipal Science and Technology Major Project (2021SHZDZX0100)Shanghai Municipal Commission of Science and Technology Project (19511132101)National Natural Science Foundation of China (62088101, 61720106011, and 62173034)
文摘1.Introduction Artificial intelligence(AI)is a rapidly growing field of technol-ogy,which“will enliven inert objects,much as electricity did more than a century ago.Everything that we formerly electrified will now cognitize”[1].AI advances are constantly pushing the frontier of what machines can do.Increased attention is being placed on AI research,as well as its development and deployment by commer-cial investors,defense strategists,and policy makers[2].
文摘In this work, a simulated aircraft fuel tank inerting system has been successfully estab- lished based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the inerting effectiveness of the system, including flow rate of the inert gas （nitrogen-enriched air）, inert gas concentration, fuel load of the tank and different inerting approaches. The experimental results show that under the same operating conditions, the time span of a complete inerting process decreased as the flow rate of inert gas was increased; the time span using the inert gas with 5% oxygen concentration was much longer than that using pure nitrogen; when the fuel tank was inerted using the ullage washing approach, the time span increased as the fuel load was decreased; the ullage washing approach showed the best inerting performance when the time span of a complete inerting process was the evaluation criterion, but when the decrease of dissolved oxygen concentration in the fuel was also considered to characterize the inerting effective- ness, the approach of ullage washing and fuel scrubbing at the same time was the most effective.
基金supported by Funding of Jiangsu Innovation Program for Graduate Education of China (No.KYLX15_0231)Postgraduate Research & Practice Innovation Program of Jiangsu Province of China (No.KYCX17_0279)+1 种基金the Fundamental Research Funds for the Central Universities,Aviation Industry Corporation of China Technology Innovation Fund for Fundamental Research (No.2014D60931R)Funding of Ministry of Industry and Information Technology for Civil Aircraft
文摘Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.
基金supported by the National Natural Science Foundation of China(51404035)Beijing Nova program(Z161100004916108)
文摘To clearly elucidate the oxidative roasting behaviors of the bastnaesite, the thermal decomposition and oxidation of the bastnaesite concentrate in inert and oxidative atmosphere have been investigated in detail. Experimental data indicated that the initial decomposition temperature of the concentrate under N2 atmosphere is 150 ℃ higher than that under O2 atmosphere,most likely because the oxidation of the cerium induces the decomposition of the concentrate. For the roasted samples under N2 atmosphere at500 ℃ and above,the oxidation efficiency of the cerium is 19.8%-26.8% because of the fact that rareearth fluorocarbonate is first decomposed to form rare-earth oxyfluoride and CO2, and the cerium oxyfluoride is then partially oxidized by the CO2 gas. The rest cerium in these samples can be further oxidized in air at room temperature, with the oxidation efficiency of the cerium gradually increasing to above 80% in 7 d. This can be attributed to the obvious changes in the inner morphology of the roasted samples under N2 atmosphere at high temperatures, which largely induce the diffusion of the air and improves the oxidation activity of CeOF, and further induces the oxidation of CeOF by the air. XRD and XPS techniques were used to further verify the significant differences in the thermal decomposition behaviors of the bastnaesite concentrate under N2 and O2 atmosphere. Moreover, no oxidation of Pr^（3＋） to Pr^（4＋） in the roasted samples under both N2 and O2 atmosphere is observed. This gives an overall understanding of the oxidative roasting of the bastnaesite concentrate without additives.
文摘Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. So with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water(SCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20—70℃ proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid.
基金The authors would like to acknowledge Ministry ofScience,Technology and Innovation Malaysia(MOSTI)eScience Fund for funding the research project(04-05-05-SF0008).
文摘Decomposition of hydroxylammonium nitrate (HAN) solution with electrolytic decomposition method has attracted much attention in recent years due to its efficiencies and practicability.However,the phenomenon has not been well-studied till now. By utilizing mathematical model currently available,the effect of water content and power used for decomposition was studied. Experiment data shows that sacrificial material such as copper or aluminum outperforms inert electrodes in the decomposition of HAN solution. In the case of using copper wire to electrolyse HAN solutions, approximately 10 seconds is required to reach 100℃ regardless of concentration of HAN. In tem of power consumption,100W-300W was found to be the range in which decomposition could be triggered effectively using copper wire as electrodes.
基金financially supported by the Natural Science Foundation Project of Chongqing City (No.cstc2012jjA50002)
文摘Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone （HAZ） increases and grains in the fusion zone （FZ） coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175℃ for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.
基金funding support from the National Natural Science Foundation of China (51722404 and 51674177)
文摘Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within this field. Molten salt CO_2 capture and electrochemical transformation(MSCC-ET) process is a desirable method due to a high CO_2 solubility, a wide potential window of molten salts and easily-controlled electrode reactions. Generally, electro-splitting CO_2 in molten salts begins with CO_2 absorption reactions to form CO_3^(2-), which is then followed by the carbon deposition at the cathode and O_2 evolution at the anode. As a result, CO_2 is electro-converted to O_2 and carbon with different morphologies, compositions, microstructures and functional properties. This report introduces the MSCC-ET process, summarizes the reactions occurring in the molten salts and at the electrode surfaces, as well as the morphological variations of the cathodic products. The inert anode materials, cost estimation and scale-up evaluation of the process are then discussed. It is presumed that with a comprehensive understanding of the electrode reactions during electrolysis and the functional properties of carbon materials obtained during CO_2 electro-splitting can provide a foundation for further developing this environmentally friendly process.
基金We are grateful for the financial support from the Natural Science Foundation of Hunan Province(Grant No.04JJ0388)and from Central South University.
文摘LiFePO4/C was synthesized by high temperature solid-state method with cheap Fe2O3, LiH2PO4 and glucose as raw materials in absence of inert gas. The sample had ordered olivine-type structure other impurities characterized by the test of X-ray diffraction （XRD）. The charge-discharge test showed the sample could demonstrate 120.5 mAh/g at 0.2C rate with good cyclic capability. The powder microeleetrode cyclic voltammetry test indicated that the redox process of the sample had good reversibility.
基金Project (MKPT-2005-16ZD) supported by the National Key Scientific and Technological Project of ChinaProject supported by the Postdoctoral Science Foundation of Central South University,China
文摘In order to study the welding process,microstructure and properties of Al-Mg-Mn-Sc-Zr alloy,comparative methods of friction stir welding（FSW） and tungsten inert gas（TIG） were applied to the two conditions of this alloy,namely hot rolled plate and cold rolled-annealed plate.The relationships between microstructures and properties of the welded joints were investigated by means of optical microscopy and transmission electron microscopy.Compared with the base metal,the strength of FSW and TIG welded joints decreased,and the FSW welding coefficients were higher than the TIG welding coefficients.The loss of substructure strengthening and a very little loss of precipitation strengthening of Al3（Sc,Zr） cause the decreased strength of FSW welded joint.But for the TIG welded joint,the disappearance of both the strain hardening and most precipitation strengthening effect of Al3（Sc,Zr） particles contributed to its softening.At the same time,the grains in weld nugget zone of FSW welded joints were finer than those in the molten zone of TIG welded joints.
文摘ZnFe 2O 4 and ZnFe 2O 4 based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni 2O 3 CuO, Cu, ZnO and CeO 2 would increase the electrical conductivity, and the ZnFe 2O 4 based anodes with these additives were of good corrosion resistance. The current density on anode, the mole ratio of NaF/AlF 3 (MR) and the content of alumina in the bath effect the anode corrosion rate in different way.
基金Project(51771160)supported by the National Natural Science Foundation of ChinaProject(2018JJ4048)supported by the Provincial and Municipal Joint Fund for Natural Science of Hunan Province,China
文摘The dissimilar joints of AZ61 and ZK60 magnesium alloys were obtained by tungsten inert gas arc(TIG)welding and activating tungsten inert gas arc(A-TIG)welding processes.Microstructure characterization shows that,the fineα-Mg equiaxed dendrite crystals contained Mg17Al12 and MgZn2 particles in the fusion zone.The average size of theα-Mg grains in the fusion zone was refined to 19μm at welding current of 80 A,which resulted in the largest tensile strength of 207 MPa.The tensile strength and the width of the beam of the A-TIG welded AZ61/ZK60 joints showed strong dependence on the amount of TiO2.However,the inhomogeneity of the heat-affected zone near different base metals presented no significant effect on the mechanical properties of the welded joint.
文摘Metal powders of superlative quality, i.e. high cleanliness, rapidly solidified and spherical shape, have seen an increasing demand in the market. The leading technology for the production of such powders is the inert gas atomization of metal alloy melts. To fulfill these requirements, the metal alloy is usually produced in a vacuum induction melting furnace (VI-GA = vacuum induction melting/gas atomization) and poured by means of a preheated tundish system into a gas nozzle where the metal stream is disintegrated by a high kinetic energy inert gas jet. The produced micro-droplets solidify in a free fall inside the atomization tower. For special applications, super-clean and ceramic-free metal powders can be produced by using the EIGA (electrode induction melting/gas atomization) melting- and atomizing system. As an alternative to the metal powder route, the sprayforming technology allows to produce semi-finished products in one step. In this case, the metal droplets produced by the high-energy inert gas nozzle system are directly solidified on a substrate, allowing to form billets, rolls and tubes.
基金Project (2005CB623703) supported by the National Basic Research Program of ChinaProject (50721003) supported by the National Natural Science Fund for Innovation Group of ChinaProject (2008AA030501) supported by the National High-Tech Research and Development Program of China
文摘17（Cu-10Ni）-（NiFe2O4-10NiO） cermets were prepared by cold pressing and sintering in nitrogen atmosphere, and tested as inert anode for aluminum electrolysis at 960 °C for 10 and 40 h, respectively. Microstructures and phase compositions of the as-sintered and post-electrolyzed samples were investigated. The impurity contents in the electrolyte and the cathode metal were detected in order to investigate the corrosion characteristic of the elements of Fe, Ni and Cu in the anode. A dense NiFe2O4 layer was observed on the surface of anode and thickened with prolonging the electrolysis time. In the newly formed dense ceramic layer, NiO phase disappeared as a result of being swallowed by NiFe2O4 phase, and the metal phase was oxidized during the electrolysis in which Cu element showed a higher dissolution rate than Fe and Ni elements. The formation process of the dense ceramic layer during the electrolysis was presented and explained by using the corrosion mode of the metal phase and the transformation mechanism from NiO phase to NiFe2O4 phase.
文摘建立气相色谱法测定氟苯尼考中二乙胺和三乙胺残留的方法。采用Inert Cap for Amines毛细管胺类测试柱,经惰性处理的衬管,载气为氮气,流速3.0 mL/min,分流比为5∶1,检测器为FID。结果表明:该方法中二乙胺、三乙胺与其相邻峰完全分离;对照峰面积RSD均小于2%;二乙胺的检测限浓度为1.84μg/mL,定量限浓度为3.67μg/mL,在3.67~13.76μg/mL浓度范围内线性相关系数r为0.995 9;三乙胺的检测限浓度为0.50μg/mL,定量限浓度为1.50μg/mL,在1.50~374.63μg/mL浓度范围内线性相关系数r为0.998 6;二乙胺的回收率90.7%~103.0%,三乙胺的回收率90.8%~97.3%;小幅改变色谱条件,耐用性良好。方法操作简单、准确度高、重复性好,适用于氟苯尼考中二乙胺、三乙胺残留的测定。
