This paper aims to explore the effects of market-oriented reforms on industrial technology progress.Based on a theoretical analysis,we performed an empirical study with a marketization index and panel data of high-tec...This paper aims to explore the effects of market-oriented reforms on industrial technology progress.Based on a theoretical analysis,we performed an empirical study with a marketization index and panel data of high-tech sectors in China.We found that market-oriented reforms had significantly propelled technology progress in China’s high-tech sectors,and the effects became more evident after China’s WTO entry.Market-oriented reforms induced technology progress by increasing capital allocation efficiency,R&D input,and technology diffusion.Among various aspects of market-oriented reforms,the institutional environment exerted the most significant effects,followed by the economy’s non-state sector,product market development,and factor market development;the government-market relationship index influenced technology’s progress the least.The effects are heterogeneous across sectors with different technology attributes and more significant for technology-intensive sectors.Our findings offer policy implications for China’s ongoing market-oriented reforms and policy design for technology progress in high-tech sectors.展开更多
Crude oil imports in China are mainly carried out by state-owned entities with non state-owned entities as compliment. Crude imported by 5 state-owned entities accounts for 90% of the total imports, while non state-ow...Crude oil imports in China are mainly carried out by state-owned entities with non state-owned entities as compliment. Crude imported by 5 state-owned entities accounts for 90% of the total imports, while non state-owned entities are about given more freedom in using and importing crude. In 2015 only, there were 13 companies granted with access to imported crude oil and 6 were qualified to import rights. Currently, there are 29 non-state-owned companies engaging in crude import business. China oil market is faced with severe challenges. The growth rate of oil demand declined, and dependence upon imported oil increased and reached as high as 61.26% in 2015. Refined oil demand growth also slowed down, and oil refining overcapacity got prominent and completion would become fiercer in future. Overcapacity was about 140 million tons per year in 2015. Consumption ratio of diesel to gasoline went on declining, and the task of product structure adjustment was heavy. China oil market is undergoing great transformation, and institutional mechanism will go ahead, on the basis of centering on orderly release of limitations on crude oil and refined oil import and export, orderly release of competitive business and government pricing of oil/gas downstream links, vigorous resolving of overcapacity, strengthening low-carbon development, and laying a solid foundation for guarantee.展开更多
As global municipal solid waste(MSW)quantities continue to escalate,serious socio-environmental challenges arise,necessitating innovative solutions.Waste-to-hydrogen(WTH)via two-stage gasification-reforming(TSGR)prese...As global municipal solid waste(MSW)quantities continue to escalate,serious socio-environmental challenges arise,necessitating innovative solutions.Waste-to-hydrogen(WTH)via two-stage gasification-reforming(TSGR)presents an emergent technology for MSW upcycling,offering to ease waste management burdens and bolster the burgeoning hydrogen economy.Despite early initiatives to advance TSGR technology,a cohesive and critical analysis of cutting-edge knowledge and strategies to enhance hydrogen production remains lacking.This review aggregates literature on MSW upcycling to hydrogen via TSGR,with a focus on optimizing process control and catalytic efficiency.It underscores technological avenues to augment hydrogen output,curtail catalyst costs,and refine system performance.Particularly,the review illuminates the potential for integrating chemical and calcium looping into TSGR processes,identifying opportunities,and pinpointing challenges.The review concludes with a summary of the current state of techno-economic analysis for this technology,presenting outstanding challenges and future research directions,with the ultimate goal of transitioning WTH from theoretical to practical application.展开更多
To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification process.The decoupling s...To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification process.The decoupling strategy was adopted to decouple the biomass gasification process,and the composite oxygen carrier was prepared by embedding Fe_(2)O_(3) in molecular sieve SBA-16 for the chemical looping reforming process of pyrolysis micromolecular model compound methane,which was expected to realize the directional reforming of pyrolysis volatiles to prepare hydrogen-rich syngas.Thermodynamic analysis of the reaction system was carried out based on the Gibbs free energy minimization method,and the reforming performance was evaluated by a fixed bed reactor,and the kinetic parameters were solved based on the gas–solid reaction model.Thermodynamic analysis verified the feasibility of the reaction and provided theoretical guidance for experimental design.The experimental results showed that the reaction performance of Fe_(2)O_(3)@SBA-16 was compared with that of pure Fe_(2)O_(3) and Fe_(2)O_(3)@SBA-15,and the syngas yield was increased by 55.3%and 20.7%respectively,and it had good cycle stability.Kinetic analysis showed that the kinetic model changed from three-dimensional diffusion to first-order reaction with the increase of temperature.The activation energy was 192.79 kJ/mol by fitting.This paper provides basic data for the directional preparation of hydrogen-rich syngas from biomass and the design of oxygen carriers for pyrolysis of all-component chemical looping reforming.展开更多
Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane,but they are easily inactivated by the presence of trace H_(2)S.Here,we propose to modu...Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane,but they are easily inactivated by the presence of trace H_(2)S.Here,we propose to modulate both the activity and resistance to sulfur poisoning by dual substitution of Mo and Ni ions with the Fe-sites of LaFeO_(3)perovskite.It is found that partial substitution of Ni for Fe substantially improves the activity of LaFeO_(3)perovskite,while Ni particles prefer to grow and react with H_(2)S during the long-term successive redox process,resulting in the deactivation of oxygen carriers.With the presence of Mo in LaNi_(0.05)Fe_(0.95)O_(3−σ)perovskite,H_(2)S preferentially reacts with Mo to generate MoS_(2),and then the CO_(2)oxidation can regenerate Mo via removing sulfur.In addition,Mo can inhibit the accumulation and growth of Ni,which helps to improve the redox stability of oxygen carriers.The LaNi_(0.05)Mo_(0.07)Fe_(0.88)O_(3−σ)oxygen carrier exhibits stable and excellent performance,with the CH_(4)conversion higher than 90%during the 50 redox cycles in the presence of 50 ppm H_(2)S at 800℃.This work highlights a synergistic effect in the perovskite oxides induced by dual substitution of different cations for the development of high-performance oxygen carriers with excellent sulfur tolerance.展开更多
This study investigates the dry reformation of methane(DRM)over Ni/Al_(2)O_(3)catalysts in a dielectric barrier discharge(DBD)non-thermal plasma reactor.A novel hybrid machine learning(ML)model is developed to optimiz...This study investigates the dry reformation of methane(DRM)over Ni/Al_(2)O_(3)catalysts in a dielectric barrier discharge(DBD)non-thermal plasma reactor.A novel hybrid machine learning(ML)model is developed to optimize the plasma-catalytic DRM reaction with limited experimental data.To address the non-linear and complex nature of the plasma-catalytic DRM process,the hybrid ML model integrates three well-established algorithms:regression trees,support vector regression,and artificial neural networks.A genetic algorithm(GA)is then used to optimize the hyperparameters of each algorithm within the hybrid ML model.The ML model achieved excellent agreement with the experimental data,demonstrating its efficacy in accurately predicting and optimizing the DRM process.The model was subsequently used to investigate the impact of various operating parameters on the plasma-catalytic DRM performance.We found that the optimal discharge power(20 W),CO_(2)/CH_(4)molar ratio(1.5),and Ni loading(7.8 wt%)resulted in the maximum energy yield at a total flow rate of∼51 mL/min.Furthermore,we investigated the relative significance of each operating parameter on the performance of the plasma-catalytic DRM process.The results show that the total flow rate had the greatest influence on the conversion,with a significance exceeding 35%for each output,while the Ni loading had the least impact on the overall reaction performance.This hybrid model demonstrates a remarkable ability to extract valuable insights from limited datasets,enabling the development and optimization of more efficient and selective plasma-catalytic chemical processes.展开更多
Steam reforming of long-chain hydrocarbon fuels for hydrogen production has received great attention for thermal management of the hypersonic vehicle and fuel-cell application.In this work,Pt catalysts supported on Ce...Steam reforming of long-chain hydrocarbon fuels for hydrogen production has received great attention for thermal management of the hypersonic vehicle and fuel-cell application.In this work,Pt catalysts supported on CeO_(2)and Tb-doped CeO_(2)were prepared by a precipitation method.The physical structure and chemical properties of the as-prepared catalysts were characterized by powder X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Raman spectroscopy,H_(2)temperature programmed reduction,and X-ray photoelectron spectroscopy.The results show that Tb-doped CeO_(2)supported Pt possesses abundant surface oxygen vacancies,good inhibition of ceria sintering,and strong metal-support interaction compared with CeO_(2)supported Pt.The catalytic performance of hydrogen production via steam reforming of long-chain hydrocarbon fuels(n-dodecane)was tested.Compared with 2Pt/CeO_(2),2Pt/Ce_(0.9)Tb_(0.1)O_(2),and 2Pt/Ce_(0.5)Tb_(0.5)O_(2),the 2Pt/Ce_(0.7)Tb_(0.3)O_(2)has higher activity and stability for hydrogen production,on which the conversion of n-dodecane was maintained at about 53.2%after 600 min reaction under 700℃at liquid space velocity of 9 ml·g^(-1)·h^(-1).2Pt/CeO_(2)rapidly deactivated,the conversion of n-dodecane was reduced to only 41.6%after 600 min.展开更多
With the deepening of reform and opening up,the rural land system has experienced the evolution from contracting to transfer to the current rural revitalization strategy,and has always been closely linked to the well-...With the deepening of reform and opening up,the rural land system has experienced the evolution from contracting to transfer to the current rural revitalization strategy,and has always been closely linked to the well-being of farmers and the vigorous development of the rural economy.The reform of this system is not only a key driving force for rural economic development,but also an important cornerstone for realizing the rural revitalization strategy.Through in-depth analysis of the connotation of rural revitalization and rural land system reform,this study discusses in detail the internal dynamic mechanism of rural land system reform driving rural revitalization,and comprehensively analyzes the current implementation of rural land system reform.On this basis,this study puts forward the strategic concept of promoting the rural land system reform in the context of rural revitalization.Studies have shown that the rural land system reform has mainly played a positive role in the following four aspects in promoting rural revitalization:providing a solid material foundation for rural revitalization,optimizing the allocation of rural resources,promoting the transformation and upgrading of rural industrial structure,and promoting rural social harmony and stability.In the context of the current rural revitalization,the rural land system reform is undoubtedly one of the core issues of China s rural development.In order to further improve this system,we need to continue to optimize and innovate the rural land transfer system,the homestead reform system,and the rural collective construction land market entry system.展开更多
Compared to reforming reactions using hydrocarbons,ethanol steam reforming(ESR)is a sustainable alternative for hydrogen(H_(2))production since ethanol can be produced sustainably using biomass.This work explores the ...Compared to reforming reactions using hydrocarbons,ethanol steam reforming(ESR)is a sustainable alternative for hydrogen(H_(2))production since ethanol can be produced sustainably using biomass.This work explores the catalyst design strategies for preparing the Ni supported on ZSM-5 zeolite catalysts to promote ESR.Specifically,two-dimensional ZSM-5 nanosheet and conventional ZSM-5 crystal were used as the catalyst carriers and two synthesis strategies,i.e.,in situ encapsulation and wet impregnation method,were employed to prepare the catalysts.Based on the comparative characterization of the catalysts and comparative catalytic assessments,it was found that the combination of the in situ encapsulation synthesis and the ZSM-5 nanosheet carrier was the effective strategy to develop catalysts for promoting H_(2) production via ESR due to the improved mass transfer(through the 2-D structure of ZSM-5 nanosheet)and formation of confined small Ni nanoparticles(resulted via the in situ encapsulation synthesis).In addition,the resulting ZSM-5 nanosheet supported Ni catalyst also showed high Ni dispersion and high accessibility to Ni sites by the reactants,being able to improve the activity and stability of catalysts and suppress metal sintering and coking during ESR at high reaction temperatures.Thus,the Ni supported on ZSM-5 nanosheet catalyst prepared by encapsulation showed the stable performance with~88% ethanol conversion and~65% H_(2) yield achieved during a 48-h longevity test at 550-C.展开更多
Biochar is a reactive carrier as it may be partially gasified with steam in steam reforming,which could influence the formation of reaction intermediates and modify catalytic behaviors.Herein,the Ni/biochar as well as...Biochar is a reactive carrier as it may be partially gasified with steam in steam reforming,which could influence the formation of reaction intermediates and modify catalytic behaviors.Herein,the Ni/biochar as well as two comparative catalysts,Ni/Al_(2)O_(3) and Ni/SiO_(2),with low nickel loading(2%(mass))was conducted to probe involvement of the varied carriers in the steam reforming.The results indicated that the Ni/biochar performed excellent catalytic activity than Ni/SiO_(2) and Ni/Al_(2)O_(3),as the biochar carrier facilitated quick conversion of the -OH from dissociation of steam to gasify the oxygen-rich carbonaceous intermediates like C=O and C-O-C,resulting in low coverage while high exposure of nickel species for maintaining the superior catalytic performance.In converse,strong adsorption of aliphatic intermediates over Ni/Al_(2)O_(3) and Ni/SiO_(2) induced serious coking with polymeric coke as the main type(21.5%and 32.1%,respectively),which was significantly higher than that over Ni/biochar(3.9%).The coke over Ni/biochar was mainly aromatic or catalytic type with nanotube morphology and high crystallinity.The high resistivity of Ni/biochar towards coking was due to the balance between formation of coke and gasification of coke and partially biochar with steam,which created developed mesopores in spent Ni/biochar while the coke blocked pores in Ni/Al_(2)O_(3) and Ni/SiO_(2) catalysts.展开更多
For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild conditions.Much attention has been paid to gC_(3)N_(4)as a...For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild conditions.Much attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of hydrogen.To improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced reduction.This catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes effectively.In addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and formate.This study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.展开更多
In recent years,the problem of farmland fragmentation has become a major obstacle to the development of modern agriculture,and the reform of“one field for one household”can effectively sort out cultivated land resou...In recent years,the problem of farmland fragmentation has become a major obstacle to the development of modern agriculture,and the reform of“one field for one household”can effectively sort out cultivated land resources,increase contracted land area,improve land utilization rate,and effectively solve the problems of contracted land dispersion and farmland fragmentation in rural areas.This paper systematically anatomized the practice and effects of“one household,one field”reform in Guoyang County,analyzed the problems existing in the implementation process,and put forward corresponding suggestions and countermeasures,in order to provide experience and reference for the reform of one field in other regions.展开更多
As two major Great Powers in the geopolitics of the Balkans,the relationship between Austria-Hungary and Russia directly affected the stability of the political situation in Europe and the Balkans.At the beginning of ...As two major Great Powers in the geopolitics of the Balkans,the relationship between Austria-Hungary and Russia directly affected the stability of the political situation in Europe and the Balkans.At the beginning of the 20th century,the Austro-Russian cooperation dominated the Macedonian reforms,but with the deepening of the reforms,the structural contradictions between the two countries were fully exposed,and the original cooperative relationship went to a rupture.This drastically changed relationship became an important factor in the restructuring of relations between the Great Powers and the Balkan states before the First World War.展开更多
In the new era of building a socialist modernization country with the goal of promoting high-quality development,we deeply analyze the knowledge system of the Introduction to Architecture course.This analysis is based...In the new era of building a socialist modernization country with the goal of promoting high-quality development,we deeply analyze the knowledge system of the Introduction to Architecture course.This analysis is based on the cross-disciplinary specialties of local applied universities and the orientation of prioritizing employment and integrating industry and education.We propose the teaching reform of“theory-practice alternation”which is adapted to the current times and societal needs.Finally,we comprehensively summarize the effectiveness of curriculum construction,in order to provide theoretical references for the implementation of fostering character and civic virtue and deepening the reform of collaborative education mechanisms.展开更多
In order to cultivate excellent clinical medical talents with a solid foundation, strong literacy, refined skills, excellent communication abilities, innovative thinking, and a strong focus on practicality, functional...In order to cultivate excellent clinical medical talents with a solid foundation, strong literacy, refined skills, excellent communication abilities, innovative thinking, and a strong focus on practicality, functional experiments have undergone a series of reforms in areas such as constructing new curriculum systems, improving teaching content, updating teaching equipment, introducing new teaching models, and enhancing teaching evaluation systems.展开更多
Medical Functional Experiment Science, a bridge between basic medicine and clinical medicine, integrates classical experimental teaching contents of three courses including physiology, pathophysiology and pharmacology...Medical Functional Experiment Science, a bridge between basic medicine and clinical medicine, integrates classical experimental teaching contents of three courses including physiology, pathophysiology and pharmacology. This course not only helps students to verify and reinforce theoretical knowledge, but also cultivates their capability of scientific thinking to discover and solve problems. Based on the characteristics of international students and current situation of the teaching platform in the laboratory at Yangtze University, this paper discusses a series of problems in the Medical Functional Experiment Science teaching for international students and puts forward some measures for teaching reform including optimizing experimental content, innovating experimental teaching methods and establishing effective experimental evaluation mode, in order to cultivate more international medical students with innovative ability.展开更多
With the rapid development of science and technology,the face of human society has undergone great changes;with the emergence of the Internet era,all kinds of educational technology,equipment,and software in vocationa...With the rapid development of science and technology,the face of human society has undergone great changes;with the emergence of the Internet era,all kinds of educational technology,equipment,and software in vocational colleges have been widely used to carry out education and teaching,and has achieved remarkable results.Based on this,colleges and universities’electronic commerce(e-commerce)professional teachers should try to rely on the Internet to build information teaching classrooms,introduce advanced methods to build efficient classrooms by integrating teaching resources,and optimize the top-level design,so as to activate the classroom atmosphere,mobilize students’emotions,make them immersed in the teaching of electronic commerce courses.In view of this,this paper combines the existing theory and experience,first analyzes the dilemma faced by the current teaching of e-commerce in vocational colleges,then discusses the practical significance of teaching reform based on the Internet era,and lastly puts forward the specific practice path.展开更多
As the core course of finance and accounting major,the study of financial management knowledge plays a positive role in promoting students’understanding of the whole financial work and enriching financial knowledge.T...As the core course of finance and accounting major,the study of financial management knowledge plays a positive role in promoting students’understanding of the whole financial work and enriching financial knowledge.This paper analyzes the necessity of financial management curriculum reform,from the design ideas,teaching content,teaching mode,and teaching methods of several aspects of vocational college financial management curriculum reform work carried on the preliminary thinking,hoping to improve the teaching quality of this course will be helpful.展开更多
The theoretical and applied characteristics of educational psychology courses in colleges and universities are prominent,and actively promoting curriculum reform is more conducive to promoting the implementation of ta...The theoretical and applied characteristics of educational psychology courses in colleges and universities are prominent,and actively promoting curriculum reform is more conducive to promoting the implementation of talent training goals,which is in line with the practical needs of social development for high-quality talents.However,curriculum reform is a systematic project,which involves the innovation of curriculum content systems,teaching methods,teaching evaluations,and so on.This paper mainly expounds on the curriculum reform path in the period of high-quality development of educational psychology in colleges and universities,hoping to play a reference role in improving the level of education management.展开更多
基金by the General Program of the National Science Foundation of China(NSFC)“Study on the Effects of Factor Price Distortion on the Technology Sophistication of Exports from High-tech Sectors and Policy Response”(Grant No.71773107).
文摘This paper aims to explore the effects of market-oriented reforms on industrial technology progress.Based on a theoretical analysis,we performed an empirical study with a marketization index and panel data of high-tech sectors in China.We found that market-oriented reforms had significantly propelled technology progress in China’s high-tech sectors,and the effects became more evident after China’s WTO entry.Market-oriented reforms induced technology progress by increasing capital allocation efficiency,R&D input,and technology diffusion.Among various aspects of market-oriented reforms,the institutional environment exerted the most significant effects,followed by the economy’s non-state sector,product market development,and factor market development;the government-market relationship index influenced technology’s progress the least.The effects are heterogeneous across sectors with different technology attributes and more significant for technology-intensive sectors.Our findings offer policy implications for China’s ongoing market-oriented reforms and policy design for technology progress in high-tech sectors.
文摘Crude oil imports in China are mainly carried out by state-owned entities with non state-owned entities as compliment. Crude imported by 5 state-owned entities accounts for 90% of the total imports, while non state-owned entities are about given more freedom in using and importing crude. In 2015 only, there were 13 companies granted with access to imported crude oil and 6 were qualified to import rights. Currently, there are 29 non-state-owned companies engaging in crude import business. China oil market is faced with severe challenges. The growth rate of oil demand declined, and dependence upon imported oil increased and reached as high as 61.26% in 2015. Refined oil demand growth also slowed down, and oil refining overcapacity got prominent and completion would become fiercer in future. Overcapacity was about 140 million tons per year in 2015. Consumption ratio of diesel to gasoline went on declining, and the task of product structure adjustment was heavy. China oil market is undergoing great transformation, and institutional mechanism will go ahead, on the basis of centering on orderly release of limitations on crude oil and refined oil import and export, orderly release of competitive business and government pricing of oil/gas downstream links, vigorous resolving of overcapacity, strengthening low-carbon development, and laying a solid foundation for guarantee.
基金supported by the National Natural Science Foundation of China(52276202)the Tsinghua-Toyota Joint Research Fund.
文摘As global municipal solid waste(MSW)quantities continue to escalate,serious socio-environmental challenges arise,necessitating innovative solutions.Waste-to-hydrogen(WTH)via two-stage gasification-reforming(TSGR)presents an emergent technology for MSW upcycling,offering to ease waste management burdens and bolster the burgeoning hydrogen economy.Despite early initiatives to advance TSGR technology,a cohesive and critical analysis of cutting-edge knowledge and strategies to enhance hydrogen production remains lacking.This review aggregates literature on MSW upcycling to hydrogen via TSGR,with a focus on optimizing process control and catalytic efficiency.It underscores technological avenues to augment hydrogen output,curtail catalyst costs,and refine system performance.Particularly,the review illuminates the potential for integrating chemical and calcium looping into TSGR processes,identifying opportunities,and pinpointing challenges.The review concludes with a summary of the current state of techno-economic analysis for this technology,presenting outstanding challenges and future research directions,with the ultimate goal of transitioning WTH from theoretical to practical application.
基金National Natural Science Foundation of China(Grant Nos:22038011,51976168)K.C.Wong Education Foundation,the Natural Science Basic Research Program of Shaanxi(Program No.2021JLM-17)+1 种基金Programme of Introducing Talents of Discipline to Universities(B23025)Innovation Capability Support Program of Shaanxi(Program Nos:2023KJXX-004,2023-CX-TD-26,2022KXJ-126).
文摘To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification process.The decoupling strategy was adopted to decouple the biomass gasification process,and the composite oxygen carrier was prepared by embedding Fe_(2)O_(3) in molecular sieve SBA-16 for the chemical looping reforming process of pyrolysis micromolecular model compound methane,which was expected to realize the directional reforming of pyrolysis volatiles to prepare hydrogen-rich syngas.Thermodynamic analysis of the reaction system was carried out based on the Gibbs free energy minimization method,and the reforming performance was evaluated by a fixed bed reactor,and the kinetic parameters were solved based on the gas–solid reaction model.Thermodynamic analysis verified the feasibility of the reaction and provided theoretical guidance for experimental design.The experimental results showed that the reaction performance of Fe_(2)O_(3)@SBA-16 was compared with that of pure Fe_(2)O_(3) and Fe_(2)O_(3)@SBA-15,and the syngas yield was increased by 55.3%and 20.7%respectively,and it had good cycle stability.Kinetic analysis showed that the kinetic model changed from three-dimensional diffusion to first-order reaction with the increase of temperature.The activation energy was 192.79 kJ/mol by fitting.This paper provides basic data for the directional preparation of hydrogen-rich syngas from biomass and the design of oxygen carriers for pyrolysis of all-component chemical looping reforming.
基金supported by the National Natural Science Foundation of China(Nos.52174279,U2202251,and 52266008)Applied Basic Research Program of Yunnan Province for Distinguished Young Scholars(No.202201AV070004)+1 种基金Central Guiding Local Science and Technology Development Fund(No.202207AA110001)the Yunnan Fundamental Research Projects(No.202301AU070027,202401AT070388).
文摘Perovskite oxides has been attracted much attention as high-performance oxygen carriers for chemical looping reforming of methane,but they are easily inactivated by the presence of trace H_(2)S.Here,we propose to modulate both the activity and resistance to sulfur poisoning by dual substitution of Mo and Ni ions with the Fe-sites of LaFeO_(3)perovskite.It is found that partial substitution of Ni for Fe substantially improves the activity of LaFeO_(3)perovskite,while Ni particles prefer to grow and react with H_(2)S during the long-term successive redox process,resulting in the deactivation of oxygen carriers.With the presence of Mo in LaNi_(0.05)Fe_(0.95)O_(3−σ)perovskite,H_(2)S preferentially reacts with Mo to generate MoS_(2),and then the CO_(2)oxidation can regenerate Mo via removing sulfur.In addition,Mo can inhibit the accumulation and growth of Ni,which helps to improve the redox stability of oxygen carriers.The LaNi_(0.05)Mo_(0.07)Fe_(0.88)O_(3−σ)oxygen carrier exhibits stable and excellent performance,with the CH_(4)conversion higher than 90%during the 50 redox cycles in the presence of 50 ppm H_(2)S at 800℃.This work highlights a synergistic effect in the perovskite oxides induced by dual substitution of different cations for the development of high-performance oxygen carriers with excellent sulfur tolerance.
基金funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No.813393D.Mei acknowledges the funding from the National Natural Science Foundation of China(No.52177149).
文摘This study investigates the dry reformation of methane(DRM)over Ni/Al_(2)O_(3)catalysts in a dielectric barrier discharge(DBD)non-thermal plasma reactor.A novel hybrid machine learning(ML)model is developed to optimize the plasma-catalytic DRM reaction with limited experimental data.To address the non-linear and complex nature of the plasma-catalytic DRM process,the hybrid ML model integrates three well-established algorithms:regression trees,support vector regression,and artificial neural networks.A genetic algorithm(GA)is then used to optimize the hyperparameters of each algorithm within the hybrid ML model.The ML model achieved excellent agreement with the experimental data,demonstrating its efficacy in accurately predicting and optimizing the DRM process.The model was subsequently used to investigate the impact of various operating parameters on the plasma-catalytic DRM performance.We found that the optimal discharge power(20 W),CO_(2)/CH_(4)molar ratio(1.5),and Ni loading(7.8 wt%)resulted in the maximum energy yield at a total flow rate of∼51 mL/min.Furthermore,we investigated the relative significance of each operating parameter on the performance of the plasma-catalytic DRM process.The results show that the total flow rate had the greatest influence on the conversion,with a significance exceeding 35%for each output,while the Ni loading had the least impact on the overall reaction performance.This hybrid model demonstrates a remarkable ability to extract valuable insights from limited datasets,enabling the development and optimization of more efficient and selective plasma-catalytic chemical processes.
基金supported by the Key Research and Design Program of Qinhuangdao(202101A005)the Science and Technology Project of Hebei Education Department(QN2023094)+2 种基金the Cultivation Project for Basic Research and Innovation of Yanshan University(2021LGQN028)the Project for Research and Development of Metal Catalysts for Photo-thermal Decomposition of Waste Plastics to Prepare Value-added Chemicals(x2023322)the Subsidy for Hebei Key Laboratory of Applied Chemistry after Operation Performance(22567616H).
文摘Steam reforming of long-chain hydrocarbon fuels for hydrogen production has received great attention for thermal management of the hypersonic vehicle and fuel-cell application.In this work,Pt catalysts supported on CeO_(2)and Tb-doped CeO_(2)were prepared by a precipitation method.The physical structure and chemical properties of the as-prepared catalysts were characterized by powder X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Raman spectroscopy,H_(2)temperature programmed reduction,and X-ray photoelectron spectroscopy.The results show that Tb-doped CeO_(2)supported Pt possesses abundant surface oxygen vacancies,good inhibition of ceria sintering,and strong metal-support interaction compared with CeO_(2)supported Pt.The catalytic performance of hydrogen production via steam reforming of long-chain hydrocarbon fuels(n-dodecane)was tested.Compared with 2Pt/CeO_(2),2Pt/Ce_(0.9)Tb_(0.1)O_(2),and 2Pt/Ce_(0.5)Tb_(0.5)O_(2),the 2Pt/Ce_(0.7)Tb_(0.3)O_(2)has higher activity and stability for hydrogen production,on which the conversion of n-dodecane was maintained at about 53.2%after 600 min reaction under 700℃at liquid space velocity of 9 ml·g^(-1)·h^(-1).2Pt/CeO_(2)rapidly deactivated,the conversion of n-dodecane was reduced to only 41.6%after 600 min.
文摘With the deepening of reform and opening up,the rural land system has experienced the evolution from contracting to transfer to the current rural revitalization strategy,and has always been closely linked to the well-being of farmers and the vigorous development of the rural economy.The reform of this system is not only a key driving force for rural economic development,but also an important cornerstone for realizing the rural revitalization strategy.Through in-depth analysis of the connotation of rural revitalization and rural land system reform,this study discusses in detail the internal dynamic mechanism of rural land system reform driving rural revitalization,and comprehensively analyzes the current implementation of rural land system reform.On this basis,this study puts forward the strategic concept of promoting the rural land system reform in the context of rural revitalization.Studies have shown that the rural land system reform has mainly played a positive role in the following four aspects in promoting rural revitalization:providing a solid material foundation for rural revitalization,optimizing the allocation of rural resources,promoting the transformation and upgrading of rural industrial structure,and promoting rural social harmony and stability.In the context of the current rural revitalization,the rural land system reform is undoubtedly one of the core issues of China s rural development.In order to further improve this system,we need to continue to optimize and innovate the rural land transfer system,the homestead reform system,and the rural collective construction land market entry system.
基金funding from the European Union's Horizon 2020 Research and Innovation Program(872102)P.S.thanks the Science Achievement Scholarship of Thailand(SAST)for her research secondment at The University of Manchester.Y.J.thanks the National Natural Science Foundation of China(22378407)for funding.
文摘Compared to reforming reactions using hydrocarbons,ethanol steam reforming(ESR)is a sustainable alternative for hydrogen(H_(2))production since ethanol can be produced sustainably using biomass.This work explores the catalyst design strategies for preparing the Ni supported on ZSM-5 zeolite catalysts to promote ESR.Specifically,two-dimensional ZSM-5 nanosheet and conventional ZSM-5 crystal were used as the catalyst carriers and two synthesis strategies,i.e.,in situ encapsulation and wet impregnation method,were employed to prepare the catalysts.Based on the comparative characterization of the catalysts and comparative catalytic assessments,it was found that the combination of the in situ encapsulation synthesis and the ZSM-5 nanosheet carrier was the effective strategy to develop catalysts for promoting H_(2) production via ESR due to the improved mass transfer(through the 2-D structure of ZSM-5 nanosheet)and formation of confined small Ni nanoparticles(resulted via the in situ encapsulation synthesis).In addition,the resulting ZSM-5 nanosheet supported Ni catalyst also showed high Ni dispersion and high accessibility to Ni sites by the reactants,being able to improve the activity and stability of catalysts and suppress metal sintering and coking during ESR at high reaction temperatures.Thus,the Ni supported on ZSM-5 nanosheet catalyst prepared by encapsulation showed the stable performance with~88% ethanol conversion and~65% H_(2) yield achieved during a 48-h longevity test at 550-C.
基金supported by National Natural Science Foundation of China(51876080)the Program for Taishan Scholars of Shandong Province Government,the Agricultural Innovation Program of Shandong Province(SD2019NJ015)+1 种基金the Research and Development program of Shandong Basan Graphite New Material Plant,National Natural Science Foundation of China(52076097)Key projects for inter-governmental cooperation in international science,technology and innovation(2018YFE0127500).
文摘Biochar is a reactive carrier as it may be partially gasified with steam in steam reforming,which could influence the formation of reaction intermediates and modify catalytic behaviors.Herein,the Ni/biochar as well as two comparative catalysts,Ni/Al_(2)O_(3) and Ni/SiO_(2),with low nickel loading(2%(mass))was conducted to probe involvement of the varied carriers in the steam reforming.The results indicated that the Ni/biochar performed excellent catalytic activity than Ni/SiO_(2) and Ni/Al_(2)O_(3),as the biochar carrier facilitated quick conversion of the -OH from dissociation of steam to gasify the oxygen-rich carbonaceous intermediates like C=O and C-O-C,resulting in low coverage while high exposure of nickel species for maintaining the superior catalytic performance.In converse,strong adsorption of aliphatic intermediates over Ni/Al_(2)O_(3) and Ni/SiO_(2) induced serious coking with polymeric coke as the main type(21.5%and 32.1%,respectively),which was significantly higher than that over Ni/biochar(3.9%).The coke over Ni/biochar was mainly aromatic or catalytic type with nanotube morphology and high crystallinity.The high resistivity of Ni/biochar towards coking was due to the balance between formation of coke and gasification of coke and partially biochar with steam,which created developed mesopores in spent Ni/biochar while the coke blocked pores in Ni/Al_(2)O_(3) and Ni/SiO_(2) catalysts.
基金supported by the National Natural Science Foundation of China(51672081)the Program of Tri-three Talents Project of Hebei Province(China,A202110002)+1 种基金the Young Top Talents Fund Program of Higher Education Institutions of Heibei Province(BJ2020009)the Project of Science and Technology Innovation Team,Tangshan(20130203D)。
文摘For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild conditions.Much attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of hydrogen.To improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced reduction.This catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes effectively.In addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and formate.This study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.
文摘In recent years,the problem of farmland fragmentation has become a major obstacle to the development of modern agriculture,and the reform of“one field for one household”can effectively sort out cultivated land resources,increase contracted land area,improve land utilization rate,and effectively solve the problems of contracted land dispersion and farmland fragmentation in rural areas.This paper systematically anatomized the practice and effects of“one household,one field”reform in Guoyang County,analyzed the problems existing in the implementation process,and put forward corresponding suggestions and countermeasures,in order to provide experience and reference for the reform of one field in other regions.
文摘As two major Great Powers in the geopolitics of the Balkans,the relationship between Austria-Hungary and Russia directly affected the stability of the political situation in Europe and the Balkans.At the beginning of the 20th century,the Austro-Russian cooperation dominated the Macedonian reforms,but with the deepening of the reforms,the structural contradictions between the two countries were fully exposed,and the original cooperative relationship went to a rupture.This drastically changed relationship became an important factor in the restructuring of relations between the Great Powers and the Balkan states before the First World War.
基金by 2023 Research Topics of Hubei Education Science Planning(2023GB119)Provincial Teaching Reform Research Program for Undergraduate Colleges and Universities in Hubei in 2023(2023584)Pilot Curriculum Reform Project of College of Science and Technology of China Three Gorges University in 2023.
文摘In the new era of building a socialist modernization country with the goal of promoting high-quality development,we deeply analyze the knowledge system of the Introduction to Architecture course.This analysis is based on the cross-disciplinary specialties of local applied universities and the orientation of prioritizing employment and integrating industry and education.We propose the teaching reform of“theory-practice alternation”which is adapted to the current times and societal needs.Finally,we comprehensively summarize the effectiveness of curriculum construction,in order to provide theoretical references for the implementation of fostering character and civic virtue and deepening the reform of collaborative education mechanisms.
文摘In order to cultivate excellent clinical medical talents with a solid foundation, strong literacy, refined skills, excellent communication abilities, innovative thinking, and a strong focus on practicality, functional experiments have undergone a series of reforms in areas such as constructing new curriculum systems, improving teaching content, updating teaching equipment, introducing new teaching models, and enhancing teaching evaluation systems.
文摘Medical Functional Experiment Science, a bridge between basic medicine and clinical medicine, integrates classical experimental teaching contents of three courses including physiology, pathophysiology and pharmacology. This course not only helps students to verify and reinforce theoretical knowledge, but also cultivates their capability of scientific thinking to discover and solve problems. Based on the characteristics of international students and current situation of the teaching platform in the laboratory at Yangtze University, this paper discusses a series of problems in the Medical Functional Experiment Science teaching for international students and puts forward some measures for teaching reform including optimizing experimental content, innovating experimental teaching methods and establishing effective experimental evaluation mode, in order to cultivate more international medical students with innovative ability.
文摘With the rapid development of science and technology,the face of human society has undergone great changes;with the emergence of the Internet era,all kinds of educational technology,equipment,and software in vocational colleges have been widely used to carry out education and teaching,and has achieved remarkable results.Based on this,colleges and universities’electronic commerce(e-commerce)professional teachers should try to rely on the Internet to build information teaching classrooms,introduce advanced methods to build efficient classrooms by integrating teaching resources,and optimize the top-level design,so as to activate the classroom atmosphere,mobilize students’emotions,make them immersed in the teaching of electronic commerce courses.In view of this,this paper combines the existing theory and experience,first analyzes the dilemma faced by the current teaching of e-commerce in vocational colleges,then discusses the practical significance of teaching reform based on the Internet era,and lastly puts forward the specific practice path.
文摘As the core course of finance and accounting major,the study of financial management knowledge plays a positive role in promoting students’understanding of the whole financial work and enriching financial knowledge.This paper analyzes the necessity of financial management curriculum reform,from the design ideas,teaching content,teaching mode,and teaching methods of several aspects of vocational college financial management curriculum reform work carried on the preliminary thinking,hoping to improve the teaching quality of this course will be helpful.
文摘The theoretical and applied characteristics of educational psychology courses in colleges and universities are prominent,and actively promoting curriculum reform is more conducive to promoting the implementation of talent training goals,which is in line with the practical needs of social development for high-quality talents.However,curriculum reform is a systematic project,which involves the innovation of curriculum content systems,teaching methods,teaching evaluations,and so on.This paper mainly expounds on the curriculum reform path in the period of high-quality development of educational psychology in colleges and universities,hoping to play a reference role in improving the level of education management.