提出了一种基于PiReformer的风功率预测模型。首先,针对海量高维传感器捕获的数据,提出融合F检验、互信息与方差分析的特征筛选方法,将3类方法提取的特征融合后输入后续预测模型。进一步,在现有Reformer模型的基础上,对嵌入层进行转置...提出了一种基于PiReformer的风功率预测模型。首先,针对海量高维传感器捕获的数据,提出融合F检验、互信息与方差分析的特征筛选方法,将3类方法提取的特征融合后输入后续预测模型。进一步,在现有Reformer模型的基础上,对嵌入层进行转置改进并引入随机噪声,显著提升了模型性能;同时,提出改进的前馈层网络,基于门控线性单元(gated linear unit,GLU)改进单一全连接层,增强对非线性特征的提取能力。此外,模型具备反向残差结构及局部敏感哈希(locality sensitive Hashing,LSH)注意力模块。将所提方法应用于实际风电场的风功率预测,相较于现有模型,取得了更高精度的预测结果。展开更多
The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer （IIR-SOFC） fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coa...The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer （IIR-SOFC） fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coated wall reformer, a catalytic annular reformer, and a novel catalytic annular-coated wall reformer were investigated with an aim to determine the most efficient internal reformer system. Among the four reformer designs, IIR-SOFC containing an annular-coated wall reformer exhibited the highest performance in terms of cell power density （0.67 W.cm 2） and electrical efficiency （68%） with an acceptable temperature gradient and a moderate pressure drop across the reformer （3.53 × 10 5 kPa）. IIR-SOFC with an annular-coated wall reformer was then studied over a range of operating conditions： inlet fuel temperature, operating pressure, steam to carbon （S ： C） ratio, gas flow pattern （co-flow and counter-flow pattern）, and natural gas compositions. The simulation results showed that the temperature gradient across the reformer could not be decreased using a lower fuel inlet temperature （1223 K-1173 K） and both the power density and electrical efficiency of the cell also decreased by lowering fuel inlet temperature. Operating in higher pressure mode （1-10 bar） improved the temperature gradient and cell performance. Increasing the S ： C ratio from 2 ： 1 to 4：1 could decrease the temperature drop across the reformer but also decrease the cell performance. The average temperature gradient was higher and smoother in IIR-SOFC under a co-flow pattern than that under a counter-flow pattern, leading to lower overpotential and higher cell performance. Natural gas compositions significantly affected the cell performance and temperature gradient. Natural gas containing lower methane content provided smoother temperature gradient in the system but showed lower power density and electrical efficiency.展开更多
Stack-integrated methanol steam reformer(MSR)/high-temperature proton exchange membrane fuel cell(HT-PEMFC)systems enable simultaneous hydrogen production and power generation within monolithic devices,significantly r...Stack-integrated methanol steam reformer(MSR)/high-temperature proton exchange membrane fuel cell(HT-PEMFC)systems enable simultaneous hydrogen production and power generation within monolithic devices,significantly reducing system complexity and costs.However,in situ heat exchange between endothermic reforming layers and exothermic fuel cell layers creates complex thermal interactions under variable loads,posing a critical challenge to stable operation.Here,we systematically evaluate the adiabatic operational limits of a fully coupled stack-integrated MSR/HT-PEMFC using three-dimensional computational fluid dynamics.Although thermoneutral operation can be achieved at 0.4 A/cm^(2) under isothermal conditions,adiabatic operation introduces temperature gradients exceeding 30℃ and elevates reformate carbon monoxide(CO)concentrations beyond 2000×10^(−6),which can irreversibly degrade fuel cell performance.Parametric analysis reveals a critical trade-off:reducing voltage or increasing methanol feed rates lowers CO levels by 38%but degrades system efficiency by 15%,highlighting an inherent safety–efficiency conflict in adiabatic systems.These findings underscore the necessity of coordinated voltage and methanol feed flow regulation,as well as strategic decoupling of MSR and PEMFC for practical implementation.展开更多
A new continuous catalytic reforming model was configured by using a molecule-based reactor module. Themodel was based on the Sinopec Research Institute of Petroleum Processing Co., Ltd. continuous catalytic reformer ...A new continuous catalytic reforming model was configured by using a molecule-based reactor module. Themodel was based on the Sinopec Research Institute of Petroleum Processing Co., Ltd. continuous catalytic reformer fullmodel, and was reduced to a size of 157 naphtha molecules (C1−C12) that underwent 764 reactions. The new model inheritedthe advantages of the original model, and had better solving performance and flexibility owing to support by the AspenHYSYS environment. Typical commercial plant data were selected for model validation, which showed advantages in theaccuracy of detailed predictions and the range of its application. In addition, the solving time was reduced from minutes toseconds. Therefore, the simplified model proved to be feasible for industrial application.展开更多
Rome was famous because of its strong military force and it dominate the Mediterranean Sea.However,it was facing severe shortage of soldiers for a long time during 150 BCE.This problem had enormously effect on the Rom...Rome was famous because of its strong military force and it dominate the Mediterranean Sea.However,it was facing severe shortage of soldiers for a long time during 150 BCE.This problem had enormously effect on the Roman society and political life such as the appearance of slavery in Rome and the use of violence in Rome.The reasons why Rome had shortage f soldiers were related to its own military system and political system.The three great reformers,Tiberius Gracchus,Caius Gracchus and Caius Marius tried their best to solve the problem.Gracchus brothers failed but Marius succeed.Experiences we can learn from these reforms will also be mentioned.展开更多
In this paper, the effect of catalyst shape and characteristics has been investigated where five types of a catalyst were examined under the same operation conditions, where catalysts are similar in the chemical prope...In this paper, the effect of catalyst shape and characteristics has been investigated where five types of a catalyst were examined under the same operation conditions, where catalysts are similar in the chemical properties (Ni/MgOAl2O3) but it's different in their physical properties in the catalyst section of secondary reformer. The secondary reformer involves continuation of the methane reforming reaction that began in the primary reformer to produce Nitrogen and Hydrogen in the ammonia plant. In order to evaluate performance of various types of catalysts in the secondary reformer reactor, mathematical model have been created. The mathematical model covers all aspects of major chemical kinetics, heat and mass transfer phenomena in the secondary reformer in the ammonia plant at steady state conditions. It aims to optimize the best catalyst from five types of catalyst of the secondary reformer reactor in the State Company of Fertilizers South Region in the Basra/Iraq. The mathematical model allows calculating the axial variations of compositions, temperature and pressure of the gases inside two reactors in series by using the atomic molar balance and adiabatic flame temperature in the combustion section while, in the catalyst section, they are predicted by using a one-dimensional heterogeneous catalytic reaction model. The analysis evaluation performance of the catalyst (RKS-2-7H') have good results than other the catalyst types (RKS - 2, ICI 54 - 2, RKS-2-7H”, RKS-2-7H”’) in catalyst zone of the secondary reformer.展开更多
For syngas production, the combustion of fossil fuels produces large amounts of CO2 as a greenhouse gas annually which intensifies global warming. In this study, chemical looping combustion （CLC） has been utilized f...For syngas production, the combustion of fossil fuels produces large amounts of CO2 as a greenhouse gas annually which intensifies global warming. In this study, chemical looping combustion （CLC） has been utilized for the elimination of CO2 emission to atmosphere during simultaneous syngas production with different H2/CO ratio in steam reforming of methane （SR） and dry reforming of methane （DR） in a CLC-SR-DR configuration. In CLC-SR-DR with 184 reformer tubes （similar to an industrial scale steam reformer in Zagros Petrochemical Company, Assaluyeh, Iran）, DR reaction occurs over Rh-based catalysts in 31 tubes. Also, SR reaction is happened over Ni-based catalysts in 153 tubes. CLC via employment of Mn-based oxygen carriers supplies heat for DR and SR reactions and produces CO2 and H2O as raw materials simultaneously. A steady state heterogeneous catalytic reaction model is applied to analyze the performance and applicability of the proposed CLC-SR-DR configuration. Simulation results show that combustion efficiency reached 1 at the outlet of fuel reactor （FR）. Therefore, pure CO2 and H2O can be recycled to DR and SR sides, respectively. Also, CH4 conversion reached 0.2803 and 0.7275 at the outlet of SR and DR sides, respectively. Simulation results indicate that, 3223 kmol.h-l syngas with a H2/CO ratio equal to 9.826 was produced in SR side of CLC-SR-DR. After that, 1844 kmol.h-1 syngas with a H2/CO ratio equal to 0.986 was achieved in DR side of CLC-SR-DR. Results illustrate that by increasing the number of DR tubes to 50 tubes and considering 184 fixed total tubes in CLC-SR-DR, CH4 conversions in SR and DR sides decreased 2.69% and 3.31%, respectively. However, this subject caused total syngas production in SR and DR sides （in all of 184 tubes） enhance to 5427 kmol-h-1. Finally, thermal and molar behaviors of the proposed configuration demonstrate that CLC-SR-DR is applicable for simultaneous syngas production with high and low Hx/CO ratios in an environmental friendly process.展开更多
In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether （DME） by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plas...In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether （DME） by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plasma and catalyst reactors is designed.A spark discharge is used as a non-equilibrium plasma source,and it is used to ionize the mixture of DME and air.The performances of the reformer are characterized experimentally in terms of gas concentrations,hydrogen yield,DME conversion ratio,and specific energy consumption.The effects of discharge frequency,reaction temperature,air-to-DME ratio and space velocity are investigated.The experimental results show that the plasma-catalyst hybrid reformer enhances hydrogen yield when reaction temperature drops below 620 ℃.At 450 ℃,hydrogen yield of hybrid reforming is almost three times that of catalyst reforming.When space velocity is 510 h-1,hydrogen yield is 67.7%,and specific energy consumption is 12.2 k J/L-H2.展开更多
Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting t...Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases(methane and carbon dioxide)into syngas and its promising industrial applications.Nickel(Ni)-based catalysts,with high catalytic activity,low cost,and abundant resources,are considered ideal candidates for industrial applications.In this article,three reaction kinetic models were briefly introduced,namely the Power-Law(PL)model,the Eley-Rideal(ER)model,and the Langmuir-Hinshelwood-Hougen-Watson(LHHW)model.Based on the LHHW model,the reaction kinetics and mechanisms of different catalytic systems were systematically discussed,including the properties of supports,the doping of noble metals and transition metals,the role of promoters,and the influence of the geometric and electronic structures of Ni on the reaction mechanism.Furthermore,the kinetics of carbon deposition and elimination on various catalysts were analyzed.Based on the reaction rate expressions for carbon elimination,the reasons for the high activity of transition metal iron(Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained.Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems,a theoretical guidance for the designing of high-performance catalysts was provided in this work.展开更多
This work proposes a novel tubular structure of high-temperature proton exchange membrane fuel cell(PEMFC)integrated with a built-in packed-bed methanol steam reformer to provide hydrogen for power output.A two-dimens...This work proposes a novel tubular structure of high-temperature proton exchange membrane fuel cell(PEMFC)integrated with a built-in packed-bed methanol steam reformer to provide hydrogen for power output.A two-dimensional axisymmetric non-isothermal model was developed in COMSOL Multiphysics 5.4 to simulate the performance of a tubular high temperature proton membrane fuel cell and a packed bed methanol reformer.The model considers the coupling multi-physical processes,including methanol reforming reaction,water gas shift reaction,methanol cracking reaction as well as the heat,mass and momentum transport processes.The sub-model of the tubular packed-bed methanol reformer is validated between 433 K and 493 K with the experimental data reported in the literature.The sub-model of the high temperature proton exchange fuel cell is validated between 393 K and 433 K with the published literature.Our results show that power output and temperature distribution of the integrated unit depend on methanol flow rates and working voltages.It was suggested that stable power generation performance of 0.14 W/cm_(2)and temperature drop in methanol steam reformer of≤10 K could be achieved by controlling the methanol space-time ratio of≥250 kg·s/mol with working voltage at 0.6 V,even in the absence of an external heat source.展开更多
China Outlines 2026 Economic Agenda with Focus on Demand and Reform Fol lowing the an nual Cent ral Economic Work Conference in December,multiple Chinese government depar tments rolled out key priorities for 2026.The ...China Outlines 2026 Economic Agenda with Focus on Demand and Reform Fol lowing the an nual Cent ral Economic Work Conference in December,multiple Chinese government depar tments rolled out key priorities for 2026.The National Development and Reform Commission(NDRC)pledged measures to stabilize investment growth,including leveraging government funds and increasing central budget investment.展开更多
This study intends to address the advent of higher education massification in Eritrea following the restructuring of higher education in 2004-2005. The study applied both qualitative and quantitative research methods....This study intends to address the advent of higher education massification in Eritrea following the restructuring of higher education in 2004-2005. The study applied both qualitative and quantitative research methods. The target respondents of the survey questionnaire in the study were instructors, graduates, students, administrative personnel of all higher education institutions. The findings reveal that, institutes of higher education in Eritrea are currently confronting low quality of education, shortage of senior national faculties, dependence on fixed government budget, lack of digitalized governance and weak technology infrastructure. The study concludes that, the higher education institutions after reform achieved commendable results in human resource development, narrowing gender inequality, linkage with domestic and external stakeholders in various areas of cooperation. Moreover, students’ admission rate and enrollment rate increased steadily, academic programs, departments, courses, research projects and consultancy services flourished and the advent of massification in general brought positive returns to Eritrea.展开更多
The fast-changing trajectory of energy systems toward renewables requires flexible,low-emission technologies that can buffer supply intermittently and offer large-scale energy storage systems.Moreso,hydrogen is increa...The fast-changing trajectory of energy systems toward renewables requires flexible,low-emission technologies that can buffer supply intermittently and offer large-scale energy storage systems.Moreso,hydrogen is increasingly viewed as a multi-scale flexibility resource capable of supporting deep decarbonization in renewable-dominated power systems,yet existing reviews often treat production,storage,and conversion technologies in isolation.Hydrogen offers the ability to convert,store and reconvert energy on various timescales.This review critically analyses the current literature of hydrogen production and storage in relation to power systems integration,synthesizing technical,economic and operational advances.The study synthesizes recent advances in electrolysis,particularly PEM and high-temperature SOEC systems,together with emerging PEC routes,biomass-to-hydrogen processes,and long-duration storage technologies.It considers,for storage,the performance and maturity of compressed gas,liquid hydrogen,metal and complex hydrides,liquid organic hydrogen carriers,and geological formations.Integration studies show that the value of hydrogen is enhanced as the share of renewables increases,providing seasonal storage,grid balancing,and sector coupling via power-to-hydrogen-to-power configurations.Yet technical,economic and other hurdles such as conversion losses,infrastructure requirements,and safety considerations are still holding back widespread implementation.The review also underlines the value of policy frameworks,such as country-level hydrogen strategies,carbon pricing,tax incentives,and harmonized safety standards to speed up adoption and reduce barriers to costs.The review synthesizes offer planners,operators,and policymakers a clear roadmap for aligning hydrogen deployment strategies with evolving technical requirements and high-renewable power-system conditions.By summarizing what is known and discussing opportunities for the future,this review is intended to be a roadmap towards maximizing hydrogen in reaching a flexible,resilient and carbon free power system.展开更多
With the advent of the AI era,how can students effectively utilize generative AI large models to assist in course learning?At the same time,how can teachers utilize generative AI tools and the teaching concept of OBE ...With the advent of the AI era,how can students effectively utilize generative AI large models to assist in course learning?At the same time,how can teachers utilize generative AI tools and the teaching concept of OBE to stimulate students’innovative consciousness and teamwork ability,enabling students to identify some problems in a certain industry or field and creatively propose feasible solutions,and truly achieve the cultivation of new models in software engineering course teaching with the assistance of generative AI tools?This paper presents research and practice on a new model for cultivating software engineering courses that integrates generative AI and OBE,introduces the specific process of teaching reform and practice,and finally explains the achievements of teaching reform.展开更多
To meet the need for cultivating application-oriented talents in local universities,this study introduced a project-based learning approach into the reform of bioinformatics experimental teaching.The course was struct...To meet the need for cultivating application-oriented talents in local universities,this study introduced a project-based learning approach into the reform of bioinformatics experimental teaching.The course was structured around a project titled"Influenza Virus Analysis",comprising four progressive modules:database utilization and information retrieval,sequence alignment and phylogenetic analysis,functional and structural prediction,and omics data analysis.These modules were integrated into a coherent research workflow that connected fragmented knowledge and technical skills.During implementation,flipped classroom and group collaboration methods were employed,alongside the establishment of a diversified assessment system emphasizing process evaluation.Teaching practice indicates that the reform effectively enhances students professional application skills,learning experience,and scientific literacy,facilitating a shift from"tool operation"to"problem-solving"capabilities.This study provides a reference model for the reform of bioinformatics experimental teaching in local universities.展开更多
Contemporary Social Sciences publishes outstanding research in the field of social sciences in China and also includes high-quality research work by foreign scholars on the development of China’s western regions and ...Contemporary Social Sciences publishes outstanding research in the field of social sciences in China and also includes high-quality research work by foreign scholars on the development of China’s western regions and its reform and opening up.The aim is to help promote China’s academic achievements to the world and give China a stronger voice in the global community of social sciences.The scopes of research fields for consideration include,but not limited to political science,economics,literature,linguistics,journalism and communication,education,sociology,philosophy,history,law,and interdisciplinary research.展开更多
Methanol steam reforming(MSR)represents a promising route for hydrogen production,leveraging the high energy density and liquid-phase storage advantages of methanol.Copper-based catalysts have become indispensable for...Methanol steam reforming(MSR)represents a promising route for hydrogen production,leveraging the high energy density and liquid-phase storage advantages of methanol.Copper-based catalysts have become indispensable for MSR due to their cost-effectiveness,exceptional catalytic activity,and tunable selectivity.However,persistent challenges such as thermal sintering,undesirable CO byproduct formation,diminished low-temperature reactivity,and long-term catalyst deactivation limit their broad industrial deployment.This review comprehensively examines the mechanistic pathways of MSR over Cu-based catalysts,with particular focus on differentiating catalyst formulations optimized for high-temperature(>200°C)versus low-temperature(<200°C)operation.It highlights the decisive influence of Cu nanoparticle size,electronic structure,and crystal structure on catalytic performance.Cutting-edge design strategies,including multi-element engineering,innovative synthesis techniques,and deactivation mitigation,are critically evaluated to elucidate mechanistic connections between atomic-scale structure and catalytic performance enhancement.Finally,industrial applications of commercial Cu/ZnO/Al_(2)O_(3)variants and their scalability challenges are discussed,alongside prospective strategies for catalyst innovation and engineering to advance next-generation hydrogen production.展开更多
The rapid development of artificial intelligence(AI)has placed significant pressure on universities to rethink how they train software engineering students.Tools like GitHub Copilot can now generate basic code in seco...The rapid development of artificial intelligence(AI)has placed significant pressure on universities to rethink how they train software engineering students.Tools like GitHub Copilot can now generate basic code in seconds.This raises important questions:What is the value of traditional programming education?What role should instructors play when AI becomes a powerful teaching assistant?How should the goals of software engineering programs change as companies increasingly use AI to handle coding tasks?This paper explores the key challenges AI brings to software engineering education and proposes practical strategies for updating talent development models to meet these changes.展开更多
文摘提出了一种基于PiReformer的风功率预测模型。首先,针对海量高维传感器捕获的数据,提出融合F检验、互信息与方差分析的特征筛选方法,将3类方法提取的特征融合后输入后续预测模型。进一步,在现有Reformer模型的基础上,对嵌入层进行转置改进并引入随机噪声,显著提升了模型性能;同时,提出改进的前馈层网络,基于门控线性单元(gated linear unit,GLU)改进单一全连接层,增强对非线性特征的提取能力。此外,模型具备反向残差结构及局部敏感哈希(locality sensitive Hashing,LSH)注意力模块。将所提方法应用于实际风电场的风功率预测,相较于现有模型,取得了更高精度的预测结果。
基金supported by the Thailand Research Fund(TRG 5680051)
文摘The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer （IIR-SOFC） fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coated wall reformer, a catalytic annular reformer, and a novel catalytic annular-coated wall reformer were investigated with an aim to determine the most efficient internal reformer system. Among the four reformer designs, IIR-SOFC containing an annular-coated wall reformer exhibited the highest performance in terms of cell power density （0.67 W.cm 2） and electrical efficiency （68%） with an acceptable temperature gradient and a moderate pressure drop across the reformer （3.53 × 10 5 kPa）. IIR-SOFC with an annular-coated wall reformer was then studied over a range of operating conditions： inlet fuel temperature, operating pressure, steam to carbon （S ： C） ratio, gas flow pattern （co-flow and counter-flow pattern）, and natural gas compositions. The simulation results showed that the temperature gradient across the reformer could not be decreased using a lower fuel inlet temperature （1223 K-1173 K） and both the power density and electrical efficiency of the cell also decreased by lowering fuel inlet temperature. Operating in higher pressure mode （1-10 bar） improved the temperature gradient and cell performance. Increasing the S ： C ratio from 2 ： 1 to 4：1 could decrease the temperature drop across the reformer but also decrease the cell performance. The average temperature gradient was higher and smoother in IIR-SOFC under a co-flow pattern than that under a counter-flow pattern, leading to lower overpotential and higher cell performance. Natural gas compositions significantly affected the cell performance and temperature gradient. Natural gas containing lower methane content provided smoother temperature gradient in the system but showed lower power density and electrical efficiency.
基金the National Key R&D Program of China(No.2022YFB3805504)Shanghai Pilot Program for Basic Research(No.22TQ1400100-7)+2 种基金the Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.22JC1400600)the Fundamental Research Funds for the Central Universities.C.Cao acknowledges the funding from Natural Science Foundation of Shanghai(No.24ZR1414900)the State Key Laboratory of Industrial Control Technology(No.ICT2024A27).
文摘Stack-integrated methanol steam reformer(MSR)/high-temperature proton exchange membrane fuel cell(HT-PEMFC)systems enable simultaneous hydrogen production and power generation within monolithic devices,significantly reducing system complexity and costs.However,in situ heat exchange between endothermic reforming layers and exothermic fuel cell layers creates complex thermal interactions under variable loads,posing a critical challenge to stable operation.Here,we systematically evaluate the adiabatic operational limits of a fully coupled stack-integrated MSR/HT-PEMFC using three-dimensional computational fluid dynamics.Although thermoneutral operation can be achieved at 0.4 A/cm^(2) under isothermal conditions,adiabatic operation introduces temperature gradients exceeding 30℃ and elevates reformate carbon monoxide(CO)concentrations beyond 2000×10^(−6),which can irreversibly degrade fuel cell performance.Parametric analysis reveals a critical trade-off:reducing voltage or increasing methanol feed rates lowers CO levels by 38%but degrades system efficiency by 15%,highlighting an inherent safety–efficiency conflict in adiabatic systems.These findings underscore the necessity of coordinated voltage and methanol feed flow regulation,as well as strategic decoupling of MSR and PEMFC for practical implementation.
基金The authors acknowledge collaboration with and support from AspenTech via the National Key R&D Program of China(2021YFA1501201).
文摘A new continuous catalytic reforming model was configured by using a molecule-based reactor module. Themodel was based on the Sinopec Research Institute of Petroleum Processing Co., Ltd. continuous catalytic reformer fullmodel, and was reduced to a size of 157 naphtha molecules (C1−C12) that underwent 764 reactions. The new model inheritedthe advantages of the original model, and had better solving performance and flexibility owing to support by the AspenHYSYS environment. Typical commercial plant data were selected for model validation, which showed advantages in theaccuracy of detailed predictions and the range of its application. In addition, the solving time was reduced from minutes toseconds. Therefore, the simplified model proved to be feasible for industrial application.
文摘Rome was famous because of its strong military force and it dominate the Mediterranean Sea.However,it was facing severe shortage of soldiers for a long time during 150 BCE.This problem had enormously effect on the Roman society and political life such as the appearance of slavery in Rome and the use of violence in Rome.The reasons why Rome had shortage f soldiers were related to its own military system and political system.The three great reformers,Tiberius Gracchus,Caius Gracchus and Caius Marius tried their best to solve the problem.Gracchus brothers failed but Marius succeed.Experiences we can learn from these reforms will also be mentioned.
文摘In this paper, the effect of catalyst shape and characteristics has been investigated where five types of a catalyst were examined under the same operation conditions, where catalysts are similar in the chemical properties (Ni/MgOAl2O3) but it's different in their physical properties in the catalyst section of secondary reformer. The secondary reformer involves continuation of the methane reforming reaction that began in the primary reformer to produce Nitrogen and Hydrogen in the ammonia plant. In order to evaluate performance of various types of catalysts in the secondary reformer reactor, mathematical model have been created. The mathematical model covers all aspects of major chemical kinetics, heat and mass transfer phenomena in the secondary reformer in the ammonia plant at steady state conditions. It aims to optimize the best catalyst from five types of catalyst of the secondary reformer reactor in the State Company of Fertilizers South Region in the Basra/Iraq. The mathematical model allows calculating the axial variations of compositions, temperature and pressure of the gases inside two reactors in series by using the atomic molar balance and adiabatic flame temperature in the combustion section while, in the catalyst section, they are predicted by using a one-dimensional heterogeneous catalytic reaction model. The analysis evaluation performance of the catalyst (RKS-2-7H') have good results than other the catalyst types (RKS - 2, ICI 54 - 2, RKS-2-7H”, RKS-2-7H”’) in catalyst zone of the secondary reformer.
文摘For syngas production, the combustion of fossil fuels produces large amounts of CO2 as a greenhouse gas annually which intensifies global warming. In this study, chemical looping combustion （CLC） has been utilized for the elimination of CO2 emission to atmosphere during simultaneous syngas production with different H2/CO ratio in steam reforming of methane （SR） and dry reforming of methane （DR） in a CLC-SR-DR configuration. In CLC-SR-DR with 184 reformer tubes （similar to an industrial scale steam reformer in Zagros Petrochemical Company, Assaluyeh, Iran）, DR reaction occurs over Rh-based catalysts in 31 tubes. Also, SR reaction is happened over Ni-based catalysts in 153 tubes. CLC via employment of Mn-based oxygen carriers supplies heat for DR and SR reactions and produces CO2 and H2O as raw materials simultaneously. A steady state heterogeneous catalytic reaction model is applied to analyze the performance and applicability of the proposed CLC-SR-DR configuration. Simulation results show that combustion efficiency reached 1 at the outlet of fuel reactor （FR）. Therefore, pure CO2 and H2O can be recycled to DR and SR sides, respectively. Also, CH4 conversion reached 0.2803 and 0.7275 at the outlet of SR and DR sides, respectively. Simulation results indicate that, 3223 kmol.h-l syngas with a H2/CO ratio equal to 9.826 was produced in SR side of CLC-SR-DR. After that, 1844 kmol.h-1 syngas with a H2/CO ratio equal to 0.986 was achieved in DR side of CLC-SR-DR. Results illustrate that by increasing the number of DR tubes to 50 tubes and considering 184 fixed total tubes in CLC-SR-DR, CH4 conversions in SR and DR sides decreased 2.69% and 3.31%, respectively. However, this subject caused total syngas production in SR and DR sides （in all of 184 tubes） enhance to 5427 kmol-h-1. Finally, thermal and molar behaviors of the proposed configuration demonstrate that CLC-SR-DR is applicable for simultaneous syngas production with high and low Hx/CO ratios in an environmental friendly process.
基金Project(21106002)supported by the National Natural Science Foundation of ChinaProject(2010DFA72760)supported by Collaboration on Cutting-Edge Technology Development of Electric Vehicle,China
文摘In this work,hydrogen is produced from partial oxidation reforming of dimethyl ether （DME） by a plasma-catalyst hybrid reformer under atmospheric pressure.The plasma-catalyst hybrid reformer which includes both plasma and catalyst reactors is designed.A spark discharge is used as a non-equilibrium plasma source,and it is used to ionize the mixture of DME and air.The performances of the reformer are characterized experimentally in terms of gas concentrations,hydrogen yield,DME conversion ratio,and specific energy consumption.The effects of discharge frequency,reaction temperature,air-to-DME ratio and space velocity are investigated.The experimental results show that the plasma-catalyst hybrid reformer enhances hydrogen yield when reaction temperature drops below 620 ℃.At 450 ℃,hydrogen yield of hybrid reforming is almost three times that of catalyst reforming.When space velocity is 510 h-1,hydrogen yield is 67.7%,and specific energy consumption is 12.2 k J/L-H2.
基金Supported by Innovation Capability Support Program of Shaanxi(2024RS-CXTD-53,2024ZC-KJXX-096)the Key R&D Program of Shaanxi Province(2022QCY-LL-69)Xi’an Science and Technology Project(24GXFW0089)。
文摘Under the backdrop of“Carbon Peak and Carbon Neutrality”(dual carbon)goal in China,the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases(methane and carbon dioxide)into syngas and its promising industrial applications.Nickel(Ni)-based catalysts,with high catalytic activity,low cost,and abundant resources,are considered ideal candidates for industrial applications.In this article,three reaction kinetic models were briefly introduced,namely the Power-Law(PL)model,the Eley-Rideal(ER)model,and the Langmuir-Hinshelwood-Hougen-Watson(LHHW)model.Based on the LHHW model,the reaction kinetics and mechanisms of different catalytic systems were systematically discussed,including the properties of supports,the doping of noble metals and transition metals,the role of promoters,and the influence of the geometric and electronic structures of Ni on the reaction mechanism.Furthermore,the kinetics of carbon deposition and elimination on various catalysts were analyzed.Based on the reaction rate expressions for carbon elimination,the reasons for the high activity of transition metal iron(Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained.Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems,a theoretical guidance for the designing of high-performance catalysts was provided in this work.
文摘This work proposes a novel tubular structure of high-temperature proton exchange membrane fuel cell(PEMFC)integrated with a built-in packed-bed methanol steam reformer to provide hydrogen for power output.A two-dimensional axisymmetric non-isothermal model was developed in COMSOL Multiphysics 5.4 to simulate the performance of a tubular high temperature proton membrane fuel cell and a packed bed methanol reformer.The model considers the coupling multi-physical processes,including methanol reforming reaction,water gas shift reaction,methanol cracking reaction as well as the heat,mass and momentum transport processes.The sub-model of the tubular packed-bed methanol reformer is validated between 433 K and 493 K with the experimental data reported in the literature.The sub-model of the high temperature proton exchange fuel cell is validated between 393 K and 433 K with the published literature.Our results show that power output and temperature distribution of the integrated unit depend on methanol flow rates and working voltages.It was suggested that stable power generation performance of 0.14 W/cm_(2)and temperature drop in methanol steam reformer of≤10 K could be achieved by controlling the methanol space-time ratio of≥250 kg·s/mol with working voltage at 0.6 V,even in the absence of an external heat source.
文摘China Outlines 2026 Economic Agenda with Focus on Demand and Reform Fol lowing the an nual Cent ral Economic Work Conference in December,multiple Chinese government depar tments rolled out key priorities for 2026.The National Development and Reform Commission(NDRC)pledged measures to stabilize investment growth,including leveraging government funds and increasing central budget investment.
文摘This study intends to address the advent of higher education massification in Eritrea following the restructuring of higher education in 2004-2005. The study applied both qualitative and quantitative research methods. The target respondents of the survey questionnaire in the study were instructors, graduates, students, administrative personnel of all higher education institutions. The findings reveal that, institutes of higher education in Eritrea are currently confronting low quality of education, shortage of senior national faculties, dependence on fixed government budget, lack of digitalized governance and weak technology infrastructure. The study concludes that, the higher education institutions after reform achieved commendable results in human resource development, narrowing gender inequality, linkage with domestic and external stakeholders in various areas of cooperation. Moreover, students’ admission rate and enrollment rate increased steadily, academic programs, departments, courses, research projects and consultancy services flourished and the advent of massification in general brought positive returns to Eritrea.
基金funding this research work through the project number(PSAU/2025/01/38318).
文摘The fast-changing trajectory of energy systems toward renewables requires flexible,low-emission technologies that can buffer supply intermittently and offer large-scale energy storage systems.Moreso,hydrogen is increasingly viewed as a multi-scale flexibility resource capable of supporting deep decarbonization in renewable-dominated power systems,yet existing reviews often treat production,storage,and conversion technologies in isolation.Hydrogen offers the ability to convert,store and reconvert energy on various timescales.This review critically analyses the current literature of hydrogen production and storage in relation to power systems integration,synthesizing technical,economic and operational advances.The study synthesizes recent advances in electrolysis,particularly PEM and high-temperature SOEC systems,together with emerging PEC routes,biomass-to-hydrogen processes,and long-duration storage technologies.It considers,for storage,the performance and maturity of compressed gas,liquid hydrogen,metal and complex hydrides,liquid organic hydrogen carriers,and geological formations.Integration studies show that the value of hydrogen is enhanced as the share of renewables increases,providing seasonal storage,grid balancing,and sector coupling via power-to-hydrogen-to-power configurations.Yet technical,economic and other hurdles such as conversion losses,infrastructure requirements,and safety considerations are still holding back widespread implementation.The review also underlines the value of policy frameworks,such as country-level hydrogen strategies,carbon pricing,tax incentives,and harmonized safety standards to speed up adoption and reduce barriers to costs.The review synthesizes offer planners,operators,and policymakers a clear roadmap for aligning hydrogen deployment strategies with evolving technical requirements and high-renewable power-system conditions.By summarizing what is known and discussing opportunities for the future,this review is intended to be a roadmap towards maximizing hydrogen in reaching a flexible,resilient and carbon free power system.
基金supported by the Shanghai Municipal Education Research Project“Exploring the Practical Application of Generative Artificial Intelligence in Cultivating Innovative Thinking and Capabilities of Interdisciplinary Application Technology Talents‘Practice Path’”(C2025299)the university-level postgraduate course project“Software Process Management”(PX-2025251502)of Shanghai Sanda Universitythe key course project at the university level of Shanghai Sanda University,“Introduction to Software Engineering”(PX-5241216).
文摘With the advent of the AI era,how can students effectively utilize generative AI large models to assist in course learning?At the same time,how can teachers utilize generative AI tools and the teaching concept of OBE to stimulate students’innovative consciousness and teamwork ability,enabling students to identify some problems in a certain industry or field and creatively propose feasible solutions,and truly achieve the cultivation of new models in software engineering course teaching with the assistance of generative AI tools?This paper presents research and practice on a new model for cultivating software engineering courses that integrates generative AI and OBE,introduces the specific process of teaching reform and practice,and finally explains the achievements of teaching reform.
基金Supported by Undergraduate Higher Education Teaching Quality and Reform Projects of Guangdong Province(Yuejiao Gao Han[2024]No.9,Yuejiao Gao Han[2024]No.30)Guangdong Basic and Applied Basic Research Foundation(2023A1515110973)+1 种基金Guangdong Provincial Young Innovative Talents Project of General Colleges and Universities(2023KQNCX089)Quality Engineering and Teaching Reform Projects of Zhaoqing University(zlgc202239,zlgc202207,zlgc2024005,zlgc2024038).
文摘To meet the need for cultivating application-oriented talents in local universities,this study introduced a project-based learning approach into the reform of bioinformatics experimental teaching.The course was structured around a project titled"Influenza Virus Analysis",comprising four progressive modules:database utilization and information retrieval,sequence alignment and phylogenetic analysis,functional and structural prediction,and omics data analysis.These modules were integrated into a coherent research workflow that connected fragmented knowledge and technical skills.During implementation,flipped classroom and group collaboration methods were employed,alongside the establishment of a diversified assessment system emphasizing process evaluation.Teaching practice indicates that the reform effectively enhances students professional application skills,learning experience,and scientific literacy,facilitating a shift from"tool operation"to"problem-solving"capabilities.This study provides a reference model for the reform of bioinformatics experimental teaching in local universities.
文摘Contemporary Social Sciences publishes outstanding research in the field of social sciences in China and also includes high-quality research work by foreign scholars on the development of China’s western regions and its reform and opening up.The aim is to help promote China’s academic achievements to the world and give China a stronger voice in the global community of social sciences.The scopes of research fields for consideration include,but not limited to political science,economics,literature,linguistics,journalism and communication,education,sociology,philosophy,history,law,and interdisciplinary research.
基金supported by the National Natural Science Foundation of China(No.22208374)the Excellent Youth Scientist Award Foundation of Shandong Province(No.ZR2024YQ009)+2 种基金the Distinguished Young Scholars of the National Natural Science Foundation of China(No.22322814)CNPC Innovation Found(2022DQ02-0607)the Fundamental Research Funds for the Central Universities(No.24CX07006A).
文摘Methanol steam reforming(MSR)represents a promising route for hydrogen production,leveraging the high energy density and liquid-phase storage advantages of methanol.Copper-based catalysts have become indispensable for MSR due to their cost-effectiveness,exceptional catalytic activity,and tunable selectivity.However,persistent challenges such as thermal sintering,undesirable CO byproduct formation,diminished low-temperature reactivity,and long-term catalyst deactivation limit their broad industrial deployment.This review comprehensively examines the mechanistic pathways of MSR over Cu-based catalysts,with particular focus on differentiating catalyst formulations optimized for high-temperature(>200°C)versus low-temperature(<200°C)operation.It highlights the decisive influence of Cu nanoparticle size,electronic structure,and crystal structure on catalytic performance.Cutting-edge design strategies,including multi-element engineering,innovative synthesis techniques,and deactivation mitigation,are critically evaluated to elucidate mechanistic connections between atomic-scale structure and catalytic performance enhancement.Finally,industrial applications of commercial Cu/ZnO/Al_(2)O_(3)variants and their scalability challenges are discussed,alongside prospective strategies for catalyst innovation and engineering to advance next-generation hydrogen production.
基金supported in part by the Northeastern University’s 2024 Undergraduate Education and Teaching Reform Research Project:Innovation and Practice of Professional Course Teaching Paradigms in the Context of Digital Education.
文摘The rapid development of artificial intelligence(AI)has placed significant pressure on universities to rethink how they train software engineering students.Tools like GitHub Copilot can now generate basic code in seconds.This raises important questions:What is the value of traditional programming education?What role should instructors play when AI becomes a powerful teaching assistant?How should the goals of software engineering programs change as companies increasingly use AI to handle coding tasks?This paper explores the key challenges AI brings to software engineering education and proposes practical strategies for updating talent development models to meet these changes.
