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A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy 被引量:3
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作者 Sun Qian Li Dayong +1 位作者 Wang Lihua Zhang Jianlei 《China Foundry》 SCIE CAS 2011年第1期1-4,共4页
Hydrogen partial pressure is an important parameter to calculate hydrogen concentration levels in molten aluminum alloy. A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy is studied... Hydrogen partial pressure is an important parameter to calculate hydrogen concentration levels in molten aluminum alloy. A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy is studied. Dynamic and rapid measurement is realized through changing the volume of the vacuum chamber and calculating the pressure difference ΔP between the theoretical and measured pressures in the vacuum chamber. Positive ΔP indicates hydrogen transmits from melt to vacuum chamber and negative ΔP means the reverse. When ΔP is equal to zero, hydrogen transmitted from both sides reached a state of dynamical equilibrium and the pressure in the vacuum chamber is equal to the hydrogen partial pressure in the molten aluminum alloy. Compared with other existing measuring methods, the new method can significantly shorten the testing time and reduce measuring cost. 展开更多
关键词 molten aluminum alloy hydrogen partial pressure dynamic measurement rapid measurement
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HYDROGEN DISTRIBUTION AND DIFFUSION BEHAVIOUR IN HIGH PRESSURE HYDROGEN CHARGED AUSTENITIC STEEL BY IMMA
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《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1989年第9期195-201,共7页
The hydrogen distribution curve along cross-section of high pressure hydrogen charged spec- imens of 21Cr-7Ni-9Mn-N austenitic steel was obtained quantitatively by IMMA(Ion Microprobe Mass Analyzer).Thus the hydrogen ... The hydrogen distribution curve along cross-section of high pressure hydrogen charged spec- imens of 21Cr-7Ni-9Mn-N austenitic steel was obtained quantitatively by IMMA(Ion Microprobe Mass Analyzer).Thus the hydrogen solubility and diffusivity may be measured, and the hydrogen permeability and other parameters may be calculated indirectly.The hydrogen distribution in specimens either long-term aged in air or in electron beam weld seam after high pressure hydrogen charging was also examined. 展开更多
关键词 ion microprobe analysis high pressure hydrogen charging hydrogen distribution DIFFUSION austenitic steel
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Direct Production of High Pressure Hydrogen at Great Rate from Glycerol/Water/Metal Mixture
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作者 Seiichi Deguchi Norifumi Isu +1 位作者 Noriyuki Kobayashi Hajime Ohtani 《Green and Sustainable Chemistry》 2016年第3期136-142,共7页
One of the key issues facing the global society today is to find renewable and sustainable energy sources. Hydrogen has gained much attention in recent years since it is one of fuels for fuel cells. It emits no carbon... One of the key issues facing the global society today is to find renewable and sustainable energy sources. Hydrogen has gained much attention in recent years since it is one of fuels for fuel cells. It emits no carbon dioxide when it is used and so on. In this study, a great rate production of high pressure hydrogen rich gas from glycerol/water/metal mixtures was developed since glycerol has become one of the enormous industrial by-products, especially from biodiesel processing plants. It was found that cobalt was the optimum metal additive among tested metals of aluminum, cobalt, magnesium and nickel in terms of a hydrogen producing rate, a hydrogen partial pressure and a conversion ratio from 50 mol% glycerol/water mixtures under an operating temperature of 723 K. Concretely, hydrogen rich gas with concentration about 64%<sub>H<sub>2</sub></sub> and high partial pressure about 4 MPa<sub>N,H<sub>2</sub></sub> could be produced at the great producing rate of 42.9 L<sub>N,H<sub>2</sub></sub> dm<sup>-2</sup>min<sup>-1</sup> and high conversion ratio about 60%<sub>H<sub>2</sub></sub>. All the produced hydrogen rich gases from glycerol/water/metal mixtures were by no means inferior to pure hydrogen as a fuel for the polymer elec-trolyte fuel cell. 展开更多
关键词 Great-Rate hydrogen Production High Pressure hydrogen Glycerol Reforming Sustainable Energy
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Effects of Hydrogen Charging Time and Pressure on the Hydrogen Embrittlement Susceptibility of X52 Pipeline Steel Material 被引量:1
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作者 Hong-Jiang Wan Xiao-Qi Wu +2 位作者 Hong-Liang Ming Jian-Qiu Wang En-Hou Han 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2024年第2期293-307,共15页
The effects of hydrogen charging time and pressure on the hydrogen embrittlement(HE)susceptibility of X52 pipeline steel material are studied by slow strain rate tensile tests.The fracture morphologies of the specimen... The effects of hydrogen charging time and pressure on the hydrogen embrittlement(HE)susceptibility of X52 pipeline steel material are studied by slow strain rate tensile tests.The fracture morphologies of the specimens are observed by scanning electron microscopy.The HE susceptibility of the X52 pipeline steel material increases with an increase in both hydrogen charging time and hydrogen pressure.At a charging time of 96 h,the HE susceptibility index reaches 45.86%,approximately 3.6 times that at a charging time of 0 h.Similarly,a charging pressure of 4 MPa results in a HE susceptibility index of 31.61%,approximately 2.5 times higher than that at a charging pressure of 0.3 MPa. 展开更多
关键词 hydrogen embrittlement X52 pipeline steel material Tubular specimen hydrogen charging time hydrogen charging pressure
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Pore structure of unidirectional solidified lotus-type porous silicon
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作者 杨倩倩 刘源 +1 位作者 李言祥 张言 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3517-3523,共7页
Lotus-type porous silicon with elongated pores was fabricated by unidirectional solidification under pressurized hydrogen. Porosity, pore diameter, and pore length can be adjusted by changing solidification speed and ... Lotus-type porous silicon with elongated pores was fabricated by unidirectional solidification under pressurized hydrogen. Porosity, pore diameter, and pore length can be adjusted by changing solidification speed and hydrogen pressure. The porosity of the ingot is nearly constant under different solidification speeds, but decreases with the increase of hydrogen pressure. The overall porosities of ingots fabricated at different hydrogen pressures were evaluated through a theoretical model. Findings are in good agreement with experimental values. The average pore diameter and pore length increase simultaneously while the average pore aspect ratio changes slightly with the decreases of solidification speed and hydrogen pressure. The average pore length is raised from 7 to 24 mm and the pore aspect ratio is raised from 8 to 20 respectively with the average pore diameter promoted by about 0.3 mm through improving the superheat degree of the melt from 200 to 300 K. 展开更多
关键词 lotus-type porous silicon solidification speed hydrogen pressure superheat degree pore length
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Deep insight of unique phase transition behaviors and mechanism in Zr_(2)Co-H isotope system with ultra-low equilibrium pressure 被引量:1
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作者 Yang Liu Pan-Pan Zhou +7 位作者 Xue-Zhang Xiao Jia-Cheng Qi Jia-Peng Bi Tiao Ying Xing-Wen Feng Yan Shi Wen-Hua Luo Li-Xin Chen 《Rare Metals》 SCIE EI CAS CSCD 2024年第1期212-224,共13页
Efficient capture,safe storage and release of tritium from the international thermonuclear experimental reactor(ITER) reaction exhaust gas is a perplexing problem,and the development of an efficient tritium-getter mat... Efficient capture,safe storage and release of tritium from the international thermonuclear experimental reactor(ITER) reaction exhaust gas is a perplexing problem,and the development of an efficient tritium-getter material with ultra-low hydrogenation equilibrium pressure is considered as a reliable way.In this work,Zr_(2)Co alloy was selected as a tritium-getter material and prepared through induction levitation melting.Fundamental performance test results show that Zr_(2)Co exhibits an ultra-low hydrogenation equilibrium pressure of 3.22 × 10^(-6) Pa at 25℃ and excellent hydriding kinetics under a low hydrogen pressure of 0.005 MPa.Interestingly,unique phase transition behaviors were presented in Zr_(2)Co-H system.Specifically,Zr_(2)CoH_(5) formed by Zr_(2)Co hydrogenated at room temperature is initially decomposed into ZrH_(2) and ZrCoH_(3) at200 ℃.With the temperature increasing to 350 ℃,ZrCoH_(3)is dehydrogenated to ZrCo,and then ZrCo further reacts with ZrH_(2) at 650 ℃ to reform Zr_(2)Co and hydrogen.Among the staged phase transition pathways during dehydrogenation,the decomposition of Zr_(2)CoH_(5) occurs preferentially,which is well accordance with both the smallest reaction energy barrier and the maximum reaction spontaneity that are determined respectively from kinetics activation energy and thermodynamics Gibbs free energy.Furthermore,first principles calculation results indicate that the stronger binding of hydrogen in interstitial environments of ZrCoH_(3)and ZrH_(2) triggers the hydrogen-stabilized phase transformation of Zr_(2)CoH_(5).The unique phase transition mechanisms in Zr_(2)Co-H system can shed light on the further exploration and regulation of analogous staged phase transition of hydrogen storage materials. 展开更多
关键词 Zr_(2)Co alloy Tritium-getter materials Ultralow equilibrium hydrogen pressure Phase transition mechanism
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Selective butyric acid production from CO_(2)and its upgrade to butanol in microbial electrosynthesis cells
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作者 Meritxell Romans-Casas Laura Feliu-Paradeda +5 位作者 Michele Tedesco Hubertus V.M.Hamelers Lluis Bañeras M.Dolors Balaguer SebastiàPuig Paolo Dessì 《Environmental Science and Ecotechnology》 SCIE 2024年第1期119-127,共9页
Microbial electrosynthesis(MES)is a promising carbon utilization technology,but the low-value products(i.e.,acetate or methane)and the high electric power demand hinder its industrial adoption.In this study,electrical... Microbial electrosynthesis(MES)is a promising carbon utilization technology,but the low-value products(i.e.,acetate or methane)and the high electric power demand hinder its industrial adoption.In this study,electrically efficient MES cells with a low ohmic resistance of 15.7 mU m^(2)were operated galvanostatically in fed-batch mode,alternating periods of high CO_(2)and H2 availability.This promoted acetic acid and ethanol production,ultimately triggering selective(78%on a carbon basis)butyric acid production via chain elongation.An average production rate of 14.5 g m^(-2)d^(-1)was obtained at an applied current of 1.0 or 1.5 mA cm^(-2),being Megasphaera sp.the key chain elongating player.Inoculating a second cell with the catholyte containing the enriched community resulted in butyric acid production at the same rate as the previous cell,but the lag phase was reduced by 82%.Furthermore,interrupting the CO_(2)feeding and setting a constant pH2 of 1.7e1.8 atm in the cathode compartment triggered solventogenic butanol production at a pH below 4.8.The efficient cell design resulted in average cell voltages of 2.6e2.8 V and a remarkably low electric energy requirement of 34.6 kWhel kg1 of butyric acid produced,despite coulombic efficiencies being restricted to 45%due to the cross-over of O_(2)and H2 through the membrane.In conclusion,this study revealed the optimal operating conditions to achieve energy-efficient butyric acid production from CO_(2)and suggested a strategy to further upgrade it to valuable butanol. 展开更多
关键词 BIOCATHODE Bioelectrochemical system Chain elongation hydrogen partial pressure Megasphaera
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Effect of different gas releasing methods on anaerobic fermentative hydrogen production in batch cultures 被引量:2
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作者 Sheng CHANG Jianzheng LI +1 位作者 Feng LIU Ze YU 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2012年第6期901-906,共6页
Decreasing hydrogen partial pressure can not only increase the activity of the hydrogen enzyme but also decrease the products inhibition, so it is an appropriate method to enhance the fermentative hydrogen production ... Decreasing hydrogen partial pressure can not only increase the activity of the hydrogen enzyme but also decrease the products inhibition, so it is an appropriate method to enhance the fermentative hydrogen production from anaerobic mixed culture. The effect ofbiogas release method on anaerobic fermentative hydrogen production in batch culture system was compared, i.e., Owen method with intermediately release, continuous releasing method, and continuous releasing + CO2 absorbing. The experi- mental results showed that, at 35℃, initial pH 7.0 and glucose concentration of 10 g.L-1, the hydrogen produc- tion was only 28 mL when releasing gas by Owen method, while it increased two times when releasing the biogas continuously. The cumulative hydrogen production could reach 155 mL when carbon dioxide in the gas stream was continuously absorbed by 1 mol.L-1 NaOH. The results showed that acetate was dominated, accounting for 43% in the dissolved fermentation products in Owen method, whereas the butyrate predominated and reached 47%-53% of the total liquid end products when releasing gas continuously. It is concluded that the homoacetogenesis could be suppressed when absorbing CO2 in the gas phase in fermentative hydrogen production system. 展开更多
关键词 batch fermentation hydrogen production biogas releasing hydrogen pressure homoacetogenesis
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Modeling and Decentralized Predictive Control of Ejector Circulation‑Based PEM Fuel Cell Anode System for Vehicular Application 被引量:4
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作者 Bo Zhang Dong Hao +4 位作者 Jinrui Chen Caizhi Zhang Bin Chen Zhongbao Wei Yaxiong Wang 《Automotive Innovation》 EI CSCD 2022年第3期333-345,共13页
The dynamic response of fuel cell vehicle is greatly affected by the pressure of reactants.Besides,the pressure difference between anode and cathode will also cause mechanical damage to proton exchange membrane.For ma... The dynamic response of fuel cell vehicle is greatly affected by the pressure of reactants.Besides,the pressure difference between anode and cathode will also cause mechanical damage to proton exchange membrane.For maintaining the relative stability of anode pressure,this study proposes a decentralized model predictive controller(DMPC)to control the anodic supply system composed of a feeding and returning ejector assembly.Considering the important influence of load current on the system,the piecewise linearization approach and state space with current-induced disturbance compensation are com-paratively analyzed.Then,an innovative switching strategy is proposed to prevent frequent switching of the sub-model-based controllers and to ensure the most appropriate predictive model is applied.Finally,simulation results demonstrate the better stability and robustness of the proposed control schemes compared with the traditional proportion integration differentia-tion controller under the step load current,variable target and purge disturbance conditions.In particular,in the case of the DC bus load current of a fuel cell hybrid vehicle,the DMPC controller with current-induced disturbance compensation has better stability and target tracking performance with an average error of 0.15 kPa and root mean square error of 1.07 kPa. 展开更多
关键词 Proton exchange membrane fuel cell hydrogen ejector System disturbance Decentralized model predictive control hydrogen pressure control
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