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High-chromium vanadium-titanium magnetite all-pellet integrated burden optimization and softening-melting behavior based on flux pellets
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作者 Bojian Chen Tao Jiang +4 位作者 Jing Wen Guangdong Yang Tangxia Yu Fengxiang Zhu Peng Hu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第3期498-507,共10页
High-chromium vanadium-titanium magnetite(HVTM)is a crucial polymetallic-associated resource to be developed.The allpellet operation is a blast furnace trend that aims to reduce carbon dioxide emissions in the future.... High-chromium vanadium-titanium magnetite(HVTM)is a crucial polymetallic-associated resource to be developed.The allpellet operation is a blast furnace trend that aims to reduce carbon dioxide emissions in the future.By referencing the production data of vanadium-titanium magnetite blast furnaces,this study explored the softening-melting behavior of high-chromium vanadium-titanium magnetite and obtained the optimal integrated burden based on flux pellets.The results show that the burden with a composition of 70wt%flux pellets and 30wt%acid pellets exhibits the best softening-melting properties.In comparison to that of the single burden,the softening-melting characteristic temperature of this burden composition was higher.The melting interval first increased from 307 to 362℃and then decreased to 282℃.The maximum pressure drop(ΔPmax)decreased from 26.76 to 19.01 kPa.The permeability index(S)dropped from 4643.5 to 2446.8 kPa·℃.The softening-melting properties of the integrated burden were apparently improved.The acid pellets played a role in withstanding load during the softening process.The flux pellets in the integrated burden exhibited a higher slag melting point,which increased the melting temperature during the melting process.The slag homogeneity and the TiC produced by over-reduction led to the gas permeability deterioration of the single burden.The segregation of the flux and acid pellets in the HVTM proportion and basicity mainly led to the better softening-melting properties of the integrated burden. 展开更多
关键词 high-chromium vanadium-titanium magnetite softening-melting properties all pellets integrated burden flux pellets
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Synthesis and Characterization of Magnetite/Carbon Nanocomposite Thin Films for Electrochemical Applications
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作者 Suh Cem Pang Wai Hwa Khoh Suk Fun Chin 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2011年第10期873-878,共6页
Stable colloidal suspension of magnetite/starch nanocomposite was prepared by a facile and aqueous-based chemical precipitation method, Magnetite/carbon nanocomposite thin films were subsequently formed upon carboniza... Stable colloidal suspension of magnetite/starch nanocomposite was prepared by a facile and aqueous-based chemical precipitation method, Magnetite/carbon nanocomposite thin films were subsequently formed upon carbonization of the starch component by heat treatment under controlled conditions. The initial content of native sago starch as the carbon source was found to affect the microstructure and electrochemical properties of the resulted magnetite/carbon nanocomposite thin films, A specific capacitance of 124 F/g was achieved for the magnetite/carbon nanocomposite thin films as compared to that of 82 F/g for pure magnetite thin films in Na2SO4 aqueous electrolyte. 展开更多
关键词 magnetite magnetite/carbon nanocomposite Native sago starch Specific capacitance
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Novel blast furnace operation process involving charging with low-titanium vanadium–titanium magnetite carbon composite hot briquette 被引量:1
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作者 Wei Zhao Man-sheng Chu +2 位作者 Hong-tao Wang Zheng-gen Liu Ya-ting Tang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第5期501-510,共10页
An innovative process of blast furnace (BF) operation involving charging with low-titanium vanadium-titanium magnetite carbon composite hot briquette (LVTM-CCB) was proposed for utilizing LVTM and conserving energ... An innovative process of blast furnace (BF) operation involving charging with low-titanium vanadium-titanium magnetite carbon composite hot briquette (LVTM-CCB) was proposed for utilizing LVTM and conserving energy, In this study, the effect of LVTM-CCB charging ratio on the softening, melting, and dripping behaviors of the mixed burden was explored systemically, and the migration of valu- able elements V and Cr was extensively investigated. The results show that with increasing LVTM-CCB charging ratio, the softening inter- val T40 - T4 increases from 146.1℃ to 266.1℃, and the melting interval To - Ts first decreases from 137.2℃ to 129.5℃ and then increases from 129.5℃ to 133.2℃. Moreover, the cohesive zone becomes narrower and then wider, and its location shifts slightly downward. In addi- tion, the recovery ratios of V and Cr in dripped iron first increase and then decrease, reaching maximum values of 14.552% and 28.163%, respectively, when the charging ratio is 25%. A proper LVTM-CCB charging ratio would improve the softening--melting behavior of the mixed burden; however, Ti(C,N) would be generated rapidly in slag when the charging ratio exceeds 25%, which is not favorable for BF op- eration. When considering the comprehensive softening-melting behavior of the mixed burden and the recovery ratios of V and Cr, the rec- ommended LVTM-CCB charging ratio is 20%. 展开更多
关键词 blast furnace practice CHARGING magnetite briquets
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Production and Characterization of Green Biosorbent Based on Modified Corn Cob Decorated Magnetite Nanoparticles
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作者 N’guadi Blaise Allou N’goran Sévérin Eroi +2 位作者 Mougo André Tigori Patrick Atheba Albert Trokourey 《Journal of Materials Science and Chemical Engineering》 CAS 2023年第2期1-12,共12页
In most developing countries, particularly in the countries of sub-Saharan Africa, corn cobs are considered as waste polluting the environment during the harvest period of this cereal. In order to valorize this agricu... In most developing countries, particularly in the countries of sub-Saharan Africa, corn cobs are considered as waste polluting the environment during the harvest period of this cereal. In order to valorize this agricultural waste, high-performance, inexpensive and low-energy consumption magnetic bioadsorbents were prepared from corn cobs. The chemically activated raw corn cob was magnetized by coating the surface with magnetite nanoparticles. The prepared biosorbents were characterized by FT-IR, XRD, FE-SEM associated with EDX, HR-TEM, TG analysis, BET surface area analysis and XPS. The maximum specific surface area of 35.22 m<sup>2</sup>/g was reached. An attempt to use of these magnetic biosorbents for the removal of heavy metal like Cr(VI) from aqueous solution was envisaged. 展开更多
关键词 Green Biosorbent Corn Cob magnetite Nanoparticles Surface Chemistry NaOH Activation
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Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020 被引量:1
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作者 ZHU Yuanyuan ZHANG Yan ZHU Xiaohua 《Chinese Geographical Science》 SCIE CSCD 2024年第1期181-194,共14页
Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research ob... Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern. 展开更多
关键词 dietary structure structural evolution carbon emission effects carbon neutrality China
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Construction and Application of a Regional Kilometer-Scale Carbon Source and Sink Assimilation Inversion System(CCMVS-R) 被引量:1
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作者 Lifeng Guo Xiaoye Zhang +8 位作者 Junting Zhong Deying Wang Changhong Miao Licheng Zhao Zijiang Zhou Jie Liao Bo Hu Lingyun Zhu Yan Chen 《Engineering》 SCIE EI CAS CSCD 2024年第2期263-275,共13页
CO_(2)is one of the most important greenhouse gases(GHGs)in the earth’s atmosphere.Since the industrial era,anthropogenic activities have emitted excessive quantities of GHGs into the atmosphere,resulting in climate ... CO_(2)is one of the most important greenhouse gases(GHGs)in the earth’s atmosphere.Since the industrial era,anthropogenic activities have emitted excessive quantities of GHGs into the atmosphere,resulting in climate warming since the 1950s and leading to an increased frequency of extreme weather and climate events.In 2020,China committed to striving for carbon neutrality by 2060.This commitment and China’s consequent actions will result in significant changes in global and regional anthropogenic carbon emissions and therefore require timely,comprehensive,and objective monitoring and verification support(MVS)systems.The MVS approach relies on the top-down assimilation and inversion of atmospheric CO_(2)concentrations,as recommended by the Intergovernmental Panel on Climate Change(IPCC)Inventory Guidelines in 2019.However,the regional high-resolution assimilation and inversion method is still in its initial stage of development.Here,we have constructed an inverse system for carbon sources and sinks at the kilometer level by coupling proper orthogonal decomposition(POD)with four-dimensional variational(4DVar)data assimilation based on the weather research and forecasting-greenhouse gas(WRF-GHG)model.Our China Carbon Monito ring and Verification Support at the Regional level(CCMVS-R)system can continuously assimilate information on atmospheric CO_(2)and other related information and realize the inversion of regional and local anthropogenic carbon emissions and natural terrestrial ecosystem carbon exchange.Atmospheric CO_(2)data were collected from six ground-based monito ring sites in Shanxi Province,China to verify the inversion effect of regio nal anthropogenic carbon emissions by setting ideal and real experiments using a two-layer nesting method(at 27 and 9 km).The uncertainty of the simulated atmospheric CO_(2)decreased significantly,with a root-mean-square error of CO_(2)concentration values between the ideal value and the simulated after assimilation was close to 0.The total anthropogenic carbon emissions in Shanxi Province in 2019 from the assimilated inversions were approximately 28.6%(17%-38%)higher than the mean of five emission inventories using the bottomup method,showing that the top-down CCMVS-R system can obtain more comprehensive information on anthropogenic carbon emissions. 展开更多
关键词 CCMVS-R Regional carbon assimilation system Anthropogenic carbon emissions CO_(2) POD 4DVar
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Oxygen functionalization-assisted anionic exchange toward unique construction of flower-like transition metal chalcogenide embedded carbon fabric for ultra-long life flexible energy storage and conversion 被引量:1
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作者 Roshan M.Bhattarai Kisan Chhetri +5 位作者 Nghia Le Debendra Acharya Shirjana Saud Mai Cao Hoang Phuong Lan Nguyen Sang Jae Kim Young Sun Mok 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期72-93,共22页
The metal-organic framework(MOF)derived Ni–Co–C–N composite alloys(NiCCZ)were“embedded”inside the carbon cloth(CC)strands as opposed to the popular idea of growing them upward to realize ultrastable energy storag... The metal-organic framework(MOF)derived Ni–Co–C–N composite alloys(NiCCZ)were“embedded”inside the carbon cloth(CC)strands as opposed to the popular idea of growing them upward to realize ultrastable energy storage and conversion application.The NiCCZ was then oxygen functionalized,facilitating the next step of stoichiometric sulfur anion diffusion during hydrothermal sulfurization,generating a flower-like metal hydroxysulfide structure(NiCCZOS)with strong partial implantation inside CC.Thus obtained NiCCZOS shows an excellent capacity when tested as a supercapacitor electrode in a three-electrode configuration.Moreover,when paired with the biomass-derived nitrogen-rich activated carbon,the asymmetric supercapacitor device shows almost 100%capacity retention even after 45,000 charge–discharge cycles with remarkable energy density(59.4 Wh kg^(-1)/263.8μWh cm^(–2))owing to a uniquely designed cathode.Furthermore,the same electrode performed as an excellent bifunctional water-splitting electrocatalyst with an overpotential of 271 mV for oxygen evolution reaction(OER)and 168.4 mV for hydrogen evolution reaction(HER)at 10 mA cm−2 current density along with 30 h of unhinged chronopotentiometric stability performance for both HER and OER.Hence,a unique metal chalcogenide composite electrode/substrate configuration has been proposed as a highly stable electrode material for flexible energy storage and conversion applications. 展开更多
关键词 carbon cloth energy conversion energy storage FLEXIBLE metal embedding ultra-stable
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Industrial Carbon Emission Distribution and Regional Joint Emission Reduction:A Case Study of Cities in the Pearl River Basin,China 被引量:1
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作者 JIANG Hongtao YIN Jian +4 位作者 ZHANG Bin WEI Danqi LUO Xinyuan DING Yi XIA Ruici 《Chinese Geographical Science》 SCIE CSCD 2024年第2期210-229,共20页
China’s low-carbon development path will make significant contributions to achieving global sustainable development goals.Due to the diverse natural and economic conditions across different regions in China,there exi... China’s low-carbon development path will make significant contributions to achieving global sustainable development goals.Due to the diverse natural and economic conditions across different regions in China,there exists an imbalance in the distribution of car-bon emissions.Therefore,regional cooperation serves as an effective means to attain low-carbon development.This study examined the pattern of carbon emissions and proposed a potential joint emission reduction strategy by utilizing the industrial carbon emission intens-ity(ICEI)as a crucial factor.We utilized social network analysis and Local Indicators of Spatial Association(LISA)space-time trans-ition matrix to investigate the spatiotemporal connections and discrepancies of ICEI in the cities of the Pearl River Basin(PRB),China from 2010 to 2020.The primary drivers of the ICEI were determined through geographical detectors and multi-scale geographically weighted regression.The results were as follows:1)the overall ICEI in the Pearl River Basin is showing a downward trend,and there is a significant spatial imbalance.2)There are numerous network connections between cities regarding the ICEI,but the network structure is relatively fragile and unstable.3)Economically developed cities such as Guangzhou,Foshan,and Dongguan are in the center of the network while playing an intermediary role.4)Energy consumption,industrialization,per capita GDP,urbanization,science and techno-logy,and productivity are found to be the most influential variables in the spatial differentiation of ICEI,and their combination in-creased the explanatory power of the geographic variation of ICEI.Finally,through the analysis of differences and connections in urban carbon emissions under different economic levels and ICEI,the study suggests joint carbon reduction strategies,which are centered on carbon transfer,financial support,and technological assistance among cities. 展开更多
关键词 industrial carbon emission intensity carbon emission social network analysis Location Indicators of Spatial Association(LISA) geographical detector multi-scale geographically weighted regression Pearl River Basin(PRB) China
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Carbothermic reduction of vanadium titanomagnetite with the assistance of sodium carbonate 被引量:5
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作者 Luming Chen Yulan Zhen +5 位作者 Guohua Zhang Desheng Chen Lina Wang Hongxin Zhao Fancheng Meng Tao Qi 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第2期239-247,共9页
The carbothermic reduction of vanadium titanomagnetite concentrate(VTC)with the assistance of Na_(2)CO_(3)was conducted in an argon atmosphere between 1073 and 1473 K.X-ray diffraction and scanning electron microscopy... The carbothermic reduction of vanadium titanomagnetite concentrate(VTC)with the assistance of Na_(2)CO_(3)was conducted in an argon atmosphere between 1073 and 1473 K.X-ray diffraction and scanning electron microscopy were used to investigate the phase transformations during the reaction.By investigating the reaction between VTC and Na_(2)CO_(3),it was concluded that molten Na_(2)CO_(3)broke the structure of titanomagnetite by combining with the acidic oxides(Fe_(2)O_(3),TiO_(2),Al_(2)O_(3),and SiO_(2))to form a Na-rich melt and release FeO and MgO.Therefore,Na_(2)CO_(3)accelerated the reduction rate.In addition,adding Na_(2)CO_(3)also benefited the agglomeration of iron particles and the slag–metal separation by decreasing the viscosity of the slag.Thus,Na_(2)CO_(3)assisted carbothermic reduction is a promising method for treating VTC at low temperatures. 展开更多
关键词 vanadium titanomagnetite sodium carbonate phase transformation carbothermic reduction slag–metal separation
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Structural properties of residual carbon in coal gasification fine slag and their influence on flotation separation and resource utilization:A review 被引量:2
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作者 Rui Han Anning Zhou +4 位作者 Ningning Zhang Kaiqiang Guo Mengyan Cheng Heng Chen Cuicui Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第2期217-230,共14页
Coal gasification fine slag(FS)is a typical solid waste generated in coal gasification.Its current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological hazards.Separation recovery a... Coal gasification fine slag(FS)is a typical solid waste generated in coal gasification.Its current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological hazards.Separation recovery and the high-value utilization of residual carbon(RC)in FS are the keys to realizing the win-win situation of the coal chemical industry in terms of economic and environmental benefits.The structural properties,such as pore,surface functional group,and microcrystalline structures,of RC in FS(FS-RC)not only affect the flotation recovery efficiency of FS-RC but also form the basis for the high-value utilization of FS-RC.In this paper,the characteristics of FS-RC in terms of pore structure,surface functional groups,and microcrystalline structure are sorted out in accordance with gasification type and FS particle size.The reasons for the formation of the special structural properties of FS-RC are analyzed,and their influence on the flotation separation and high-value utilization of FS-RC is summarized.Separation methods based on the pore structural characterist-ics of FS-RC,such as ultrasonic pretreatment-pore-blocking flotation and pore breaking-flocculation flotation,are proposed to be the key development technologies for improving FS-RC recovery in the future.The design of low-cost,low-dose collectors containing polar bonds based on the surface and microcrystalline structures of FS-RC is proposed to be an important breakthrough point for strengthening the flotation efficiency of FS-RC in the future.The high-value utilization of FS should be based on the physicochemical structural proper-ties of FS-RC and should focus on the environmental impact of hazardous elements and the recyclability of chemical waste liquid to es-tablish an environmentally friendly utilization method.This review is of great theoretical importance for the comprehensive understand-ing of the unique structural properties of FS-RC,the breakthrough of the technological bottleneck in the efficient flotation separation of FS,and the expansion of the field of the high value-added utilization of FS-RC. 展开更多
关键词 coal gasification fine slag residual carbon pore structure surface functional groups microcrystalline structure flotation sep-aration resource utilization
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Effect of drying-wetting cycles on pore characteristics and mechanical properties of enzyme-induced carbonate precipitation-reinforced sea sand 被引量:1
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作者 Ming Huang Kai Xu +2 位作者 Zijian Liu Chaoshui Xu Mingjuan Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期291-302,共12页
Enzyme-induced carbonate precipitation(EICP)is an emanating,eco-friendly and potentially sound technique that has presented promise in various geotechnical applications.However,the durability and microscopic character... Enzyme-induced carbonate precipitation(EICP)is an emanating,eco-friendly and potentially sound technique that has presented promise in various geotechnical applications.However,the durability and microscopic characteristics of EICP-treated specimens against the impact of drying-wetting(D-W)cycles is under-explored yet.This study investigates the evolution of mechanical behavior and pore charac-teristics of EICP-treated sea sand subjected to D-W cycles.The uniaxial compressive strength(UCS)tests,synchrotron radiation micro-computed tomography(micro-CT),and three-dimensional(3D)recon-struction of CT images were performed to study the multiscale evolution characteristics of EICP-reinforced sea sand under the effect of D-W cycles.The potential correlations between microstructure characteristics and macro-mechanical property deterioration were investigated using gray relational analysis(GRA).Results showed that the UCS of EICP-treated specimens decreases by 63.7% after 15 D-W cycles.The proportion of mesopores gradually decreases whereas the proportion of macropores in-creases due to the exfoliated calcium carbonate with increasing number of D-W cycles.The micro-structure in EICP-reinforced sea sand was gradually disintegrated,resulting in increasing pore size and development of pore shape from ellipsoidal to columnar and branched.The gray relational degree suggested that the weight loss rate and UCS deterioration were attributed to the development of branched pores with a size of 100-1000 m m under the action of D-W cycles.Overall,the results in this study provide a useful guidancee for the long-term stability and evolution characteristics of EICP-reinforced sea sand under D-W weathering conditions. 展开更多
关键词 Enzyme-induced carbonate precipitation(EICP) Plant-based urease Drying-wetting(D-W)cycles Microstructure
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Selective reduction of carbon dioxide into amorphous carbon over activated natural magnetite
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作者 Zhong-qing Liu Jian Zheng +1 位作者 Yi Wang Xu Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第2期231-237,共7页
Natural magnetite formed by the isomorphism substitutions of transition metals,including Fe,Ti,Co,etc.,was activated by mechanical grinding followed by H2 reduction.The temperature-programmed reduction of hydrogen(H2-... Natural magnetite formed by the isomorphism substitutions of transition metals,including Fe,Ti,Co,etc.,was activated by mechanical grinding followed by H2 reduction.The temperature-programmed reduction of hydrogen(H2-TPR)and temperature-programmed surface reaction of carbon dioxide(CO2-TPSR)were carried out to investigate the processes of oxygen loss and CO2 reduction.The samples were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM),and energy-dispersive X-ray spectroscopy(EDS).The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H2 atmosphere.Meanwhile,the activity and selectivity of CO2 reduction into carbon were enhanced.The deposited carbon on the activated natural magnetite was confirmed as amorphous.The amount of carbon after CO2 reduction at 300°C for 90 min over the activated natural magnetite was 2.87wt%higher than that over the natural magnetite. 展开更多
关键词 carbon dioxide reduction natural magnetite isomorphism substitutions grind activation oxygen-deficient degree amorphous carbon
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Earth-abundant magnetite with carbon coatings as reversible cathodes for stretchable zinc-ion batteries
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作者 Zhao Wang Yurou Wang +2 位作者 Guoqi Wang Wei Wu Jian Zhu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第11期552-562,I0013,共12页
Earth-abundant magnetite(Fe_(3)O_(4))as cathode materials in aqueous zinc-ion batteries(ZIBs)is limited by its very low capacity and poor cycling.Here,a combined strategy based on carbon coating and electrolyte optimi... Earth-abundant magnetite(Fe_(3)O_(4))as cathode materials in aqueous zinc-ion batteries(ZIBs)is limited by its very low capacity and poor cycling.Here,a combined strategy based on carbon coating and electrolyte optimization is adopted to improve the performance of Fe_(3)O_(4).The Zn-Fe_(3)O_(4)@C batteries display specific capacities of 93 mAh g^(−1) and 81%capacity retention after 200 cycles.Such performance is attributed to the enhanced electrical conductivity and structural stability of Fe_(3)O_(4)@C nanocomposites with suppressed iron dissolution.Experimental analysis reveals that the charge storage is contributed by diffusion-limited redox reactions and surface-controlled pseudocapacitance.A stretchable Zn-Fe_(3)O_(4)@C battery is further fabricated,showing stable performance when it is bent or stretched.Fe_(3)O_(4) is a promising cathode material for cost-effective,safe,sustainable and wearable energy supplies. 展开更多
关键词 Zinc-ion batteries Stretchable batteries Earth-abundant cathodes magnetite carbon coatings
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Carbonation of Dicalcium Silicate Enhanced by Ammonia Bicarbonate and Its Mechanism
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作者 周浩 刘鹏 +1 位作者 WANG Fazhou HU Chuanlin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期69-74,共6页
The strength development law of γ-type dicalcium silicate (γ-C_(2)S) under different carbonation processes was investigated,and the carbonation mechanism of γ-C_(2)S under the action of NH_(4)HCO_(3) was clarified ... The strength development law of γ-type dicalcium silicate (γ-C_(2)S) under different carbonation processes was investigated,and the carbonation mechanism of γ-C_(2)S under the action of NH_(4)HCO_(3) was clarified by using a wide range of test methods,including XRD and SEM.A method of saturated NH_(4)HCO_(3) solution as a curing agent was identified to improve the carbonation efficiency and enhance the carbonation degree of γ-C_(2)S,and then a high-strength carbonated specimen was obtained.Microhardness analysis and SEM morphology analysis were conducted on the carbonised specimens obtained under atmospheric pressure carbonisation conditions using the curing agent.It was found that γ-C_(2)S could perform carbonisation well under atmospheric pressure,which promoted the carbonisation efficiency and decreased the carbonisation cost simultaneously.Therefore,a new carbonisation process solution was proposed for the rapid carbonisation of γ-C_(2)S. 展开更多
关键词 type dicalcium silicate carbonization process curing agent atmospheric carbonization
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Mechanical Property and Microstructure of Cement Mortar with Carbonated Recycled Powder
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作者 丁亚红 张美香 +3 位作者 YANG Xiaolin XU Ping SUN Bo GUO Shuqi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期689-697,共9页
Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbon... Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect. 展开更多
关键词 recycled powder carbonation activation compound carbonation activity index mechanical property MICROSTRUCTURE
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High-efficiency Carbonation Modification Methods of Recycled Coarse Aggregates
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作者 张美香 YANG Xiaolin +3 位作者 丁亚红 SUN Bo ZHANG Xianggang LÜXiuwen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期386-398,共13页
To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put fo... To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put forward.The carbonation effect of modified recycled coarse aggregate with three different carbonation methods was evaluated,and water absorption,apparent density and crush index of modified recycled coarse aggregate were measured.Combined with XRD,SEM,and MIP microscopic analysis,the high-efficiency carbonation strengthening mechanism of modified recycled coarse aggregate was revealed.The experimental results show that,compared with the non-carbonated recycled coarse aggregate,the physical and microscopic properties of carbonated recycled coarse aggregate are improved.The method of carbonation with nano-SiO_(2) pre-soaking can realize the high-efficiency carbonation of recycled coarse aggregate,for modified recycled coarse aggregate with the method,water absorption is reduced by 23.03%,porosity is reduced by 44.06%,and the average pore diameter is 21.82 nm.The high-efficiency carbonation strengthening mechanism show that the pre-socked nano-SiO_(2) is bound to the hydration product Ca(OH)_(2) of the old mortar with nano-scale C-S-H,which can improve the CO_(2) absorption rate,accelerate the carbonation reaction,generate more stable CaCO_(3) and nano-scale silica gel,and bond to the dense three-dimensional network structure to realize the bidirectional enhancement of nano-materials and pressurized carbonation.It is concluded that the method of carbonation with nano-SiO_(2) pre-soaking is a novel high-efficiency carbonation modification of recycled coarse aggregate. 展开更多
关键词 recycled coarse aggregate pressurized carbonation high-efficiency carbonation NANO-SIO2 strengthening mechanism
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Aboveground carbon sequestration of Cunninghamia lanceolata forests:Magnitude and drivers
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作者 Chen Wang Shuguang Liu +3 位作者 Yu Zhu Andrew R.Smith Ying Ning Deming Deng 《Forest Ecosystems》 SCIE CSCD 2024年第1期32-41,共10页
Understanding the spatial variation,temporal changes,and their underlying driving forces of carbon sequestration in various forests is of great importance for understanding the carbon cycle and carbon management optio... Understanding the spatial variation,temporal changes,and their underlying driving forces of carbon sequestration in various forests is of great importance for understanding the carbon cycle and carbon management options.How carbon density and sequestration in various Cunninghamia lanceolata forests,extensively cultivated for timber production in subtropical China,vary with biodiversity,forest structure,environment,and cultural factors remain poorly explored,presenting a critical knowledge gap for realizing carbon sequestration supply potential through management.Based on a large-scale database of 449 permanent forest inventory plots,we quantified the spatial-temporal heterogeneity of aboveground carbon densities and carbon accumulation rates in Cunninghamia lanceolate forests in Hunan Province,China,and attributed the contributions of stand structure,environmental,and management factors to the heterogeneity using quantile age-sequence analysis,partial least squares path modeling(PLS-PM),and hot-spot analysis.The results showed lower values of carbon density and sequestration on average,in comparison with other forests in the same climate zone(i.e.,subtropics),with pronounced spatial and temporal variability.Specifically,quantile regression analysis using carbon accumulation rates along an age sequence showed large differences in carbon sequestration rates among underperformed and outperformed forests(0.50 and 1.80 Mg·ha^(-1)·yr^(-1)).PLS-PM demonstrated that maximum DBH and stand density were the main crucial drivers of aboveground carbon density from young to mature forests.Furthermore,species diversity and geotopographic factors were the significant factors causing the large discrepancy in aboveground carbon density change between low-and high-carbon-bearing forests.Hotspot analysis revealed the importance of culture attributes in shaping the geospatial patterns of carbon sequestration.Our work highlighted that retaining largesized DBH trees and increasing shade-tolerant tree species were important to enhance carbon sequestration in C.lanceolate forests. 展开更多
关键词 carbon density carbon accumulation rate Forest age Spatial variation Cultural influence
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Electricity Carbon Quota Trading Scheme based on Certificateless Signature and Blockchain
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作者 Xiaodong Yang Runze Diao +2 位作者 Tao Liu Haoqi Wen Caifen Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1695-1712,共18页
The carbon tradingmarket can promote“carbon peaking”and“carbon neutrality”at low cost,but carbon emission quotas face attacks such as data forgery,tampering,counterfeiting,and replay in the electricity trading mar... The carbon tradingmarket can promote“carbon peaking”and“carbon neutrality”at low cost,but carbon emission quotas face attacks such as data forgery,tampering,counterfeiting,and replay in the electricity trading market.Certificateless signatures are a new cryptographic technology that can address traditional cryptography’s general essential certificate requirements and avoid the problem of crucial escrowbased on identity cryptography.However,most certificateless signatures still suffer fromvarious security flaws.We present a secure and efficient certificateless signing scheme by examining the security of existing certificateless signature schemes.To ensure the integrity and verifiability of electricity carbon quota trading,we propose an electricity carbon quota trading scheme based on a certificateless signature and blockchain.Our scheme utilizes certificateless signatures to ensure the validity and nonrepudiation of transactions and adopts blockchain technology to achieve immutability and traceability in electricity carbon quota transactions.In addition,validating electricity carbon quota transactions does not require time-consuming bilinear pairing operations.The results of the analysis indicate that our scheme meets existential unforgeability under adaptive selective message attacks,offers conditional identity privacy protection,resists replay attacks,and demonstrates high computing and communication performance. 展开更多
关键词 Electricity carbon trading certificateless signature blockchain forgery attack carbon quota
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Prospects for green steelmaking technology with low carbon emissions in China
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作者 Zhang Fucheng Hong Lukuo Xu Ying 《Carbon Energy》 SCIE EI CAS CSCD 2024年第2期1-24,共24页
The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel indu... The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is discussed.Additionally,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment strategies.Furthermore,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”relationship.Overall,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is discussed.In conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology. 展开更多
关键词 carbon capture and utilization carbon emission hydrogen metallurgy low-carbon technology steel industry
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Recent advances in nickel-based catalysts in eCO_(2)RR for carbon neutrality
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作者 Weikang Peng Fengfeng Li +6 位作者 Shuyi Kong Chenxi Guo Haotian Wu Jiacheng Wang Yi Shen Xianguang Meng Mingxi Zhang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第2期61-91,共31页
The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-... The excessive use of nonrenewable energy has brought about serious greenhouse effect.Converting CO_(2) into high-value-added chemicals is undoubtedly the best choice to solve energy problems.Due to the excellent cost-effectiveness and dramatic catalytic performance,nickel-based catalysts have been considered as the most promising candidates for the electrocatalytic CO_(2) reduction reaction(eCO_(2)RR).In this work,the electrocatalytic reduction mechanism of CO_(2) over Ni-based materials is reviewed.The strategies to improve the eCO_(2)RR performance are emphasized.Moreover,the research on Ni-based materials for syngas generation is briefly summarized.Finally,the prospects of nickel-based materials in the eCO_(2)RR are provided with the hope of improving transition-metal-based electrocatalysts for eCO_(2)RR in the future. 展开更多
关键词 carbon energy carbon neutrality CO_(2)reduction ELECTROCATALYSIS nickel-based materials
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