Modelling of a tubular solid oxide fuel cell with different designs of indirect internal reformer

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.

基于Reformer模型的文本情感分析

为提高中文文本情感分析任务的准确率,优化训练时长,提出基于Reformer的文本情感分析模型。利用Reformer模型的上下文语义编码能力,充分获得文本上下文的特征,提高文本分类准确率;在Transformer模型的基础上,引入局部敏感哈希注意力机制及可逆残差,降低模型的复杂度及内存的占用。在3个公开数据集上进行实验,实验结果表明,该模型在准确率及训练时间上均优于其它模型。

Three Great Reformers of the Roman Army

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.

Evaluation Performance of Different Types Catalysts of an Industrial Secondary Reformer Reactor in the Ammonia Plants

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.

Simultaneous syngas production with different H_2/CO ratio in a multi-tubular methane steam and dry reformer by utilizing of CLC

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.

Modeling of Packed Bed Methanol Steam Reformer Integrated with Tubular High Temperature Proton Exchange Membrane Fuel Cell

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.

Ethanol steam reforming over Ni/ZSM-5 nanosheet for hydrogen production

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.

State-Owned Capital Participation in Private Enterprises:A Perspective of Debt Financing

This study takes debt financing as the entry point and explores the impact of state-owned capital participation in private enterprises from the perspectives of“unarticulated rules”and“articulated rules”.The study finds that state-owned capital participation significantly reduces the debt financing costs of private enterprises and expands the scale of their debt financing.This conclusion remains valid after a series of endogeneity and robustness tests.Further analysis of the mechanism reveals that state-owned capital participation improves the debt financing of private enterprises through multiple channels:Enhancing their social reputation,mitigating the“statistical bias”they face,optimizing their information quality,and reducing the“shareholder-creditor”agency problems.This paper conceptualizes these benefits as the“complementary advantages of heterogeneous shareholders”.This not only constructs a theoretical framework for“reverse mixed-ownership reform”but also better narrates the Chinese story of“mixed-ownership reform”by adopting a more universally applicable theory of equity structure.Additionally,the paper supplements existing research on the macro-and meso-level relationship between the government and the market by exploring the government’s positive role at the micro-level.

Pt nanoclusters modified porous g-C_(3)N_(4)nanosheets to significantly enhance hydrogen production by photocatalytic water reforming of methanol

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.

Aims & Scope

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.

Congenital absence of the lateral meniscus:A case report

BACKGROUND Congenital absence of the menisci is a rare anatomical variation characterized by the absence or underdevelopment of one or both menisci in the knee joint.The menisci are crucial in load distribution,joint stability,and shock absorption.Understanding the clinical presentation,diagnosis,and management of this condition is important for optimal patient care.CASE SUMMARY A 27-year-old male with a long-standing history of knee pain underwent diagnostic arthroscopy,revealing a congenital absence of the meniscus.The patient's clinical findings,imaging results,surgical procedures,and pertinent images are detailed.This case presents a unique aspect with the congenital absence of the meniscus,contributing valuable insights to the literature on rare anatomical anomalies.CONCLUSION This case of congenital absence of the menisci highlights the diagnostic challenges posed by rare anomalies.The diagnostic arthroscopy played a crucial role in identifying the absence of the meniscus and providing an explanation for the patient's persistent knee pain.The case underscores the importance of individualized treatment approaches,including physical therapy,for optimal management of rare meniscal anomalies.Further research is warranted to explore effective management strategies for the aforementioned cases and to expand our knowledge of these rare conditions.

Practical Research on Promoting the Reform of“One Field for One Household”in Guoyang County

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.

Reform of Theory-practice Alternating Teaching of the Introduction to Architecture Course Oriented to“Employment Priority and Integration of Industry and Education”

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.

Research on Professional Teaching Reform of the E-Commerce Major in Vocational Colleges Under the Internet Era

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.

Exploration and Practice of“Guiding Interactive”Teaching in Advanced Geochemistry Courses from the Perspective of Constructivist Theory

The construction of geochemical disciplines has brought new vitality to the development of traditional geology.In the new round of“Double First-Class”discipline construction at Central South University,the course of Advanced Geochemistry has effectively stimulated students’interest in learning and further improved their scientific thinking and research innovation skills through the implementation of“Guiding Interactive”teaching reform measures,which has important theoretical significance and practical value.

Research and Practice of Course Reform in English Majors of Colleges and Universities from the Ideological and Political Perspective

There is an urgent need for high-quality talents with ideological and moral character for the development of higher education and the cultivation of English majors who meet the requirements of the times.The course reform in English majors from the ideological and political perspective is an important way to improve the comprehensive quality and moral values of students,which helps to cultivate English talents with social responsibility and innovative abilities.This paper analyzes the problems in the current courses through literature review and field research,such as the lack of ideological and political perspective and low interest of students in ideological and political content.Based on these issues,taking the course“Comprehensive English”as an example,various teaching stages were practiced from the aspects of learning objectives,learning content,learning situation,implementation ideas,implementation effects,and teaching evaluation.Additionally,some suggestions are proposed,such as integrating ideological and political content into the entire process of teaching.The teaching staff needs to possess high-level English teaching ability and ideological and political perspective,standardize the evaluation system,and integrate epistemology into the evaluation process of ideological and political education,in order to promote in-depth research and exploration of ideological and political education of English majors.

Exploration of Financial Management Curriculum Reform in Vocational College

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.

Research on the Teaching Reform of Building Information Modeling Course Based on“Post,Course,Competition,and Certificate”Integration

With the rapid development of information technology,the utilization of building information modeling(BIM)is increasingly prevalent in the construction industry.In order to cultivate BIM application-oriented talents capable of effectively addressing industry development demands,this study proposes a reform plan for BIM courses that integrates post,course,competition,and certificate.The reform plan implements the teaching methods of post-course integration,competition-based teaching integration,and course certificate integration in the BIM course.It also carries out curriculum reform from four aspects:curriculum system,teaching mode,teaching content,and assessment method.Reform should be implemented to enhance students’professional and practical skills,thereby enabling them to secure improved employment opportunities and prospects for career development.

Research on the PDSIPE Teaching Mode for English Teaching in Applied Undergraduate Colleges

PDSIPE(Planning,Design,Scene,Implementation,Product,Evaluation)is the teaching concept and teaching operation mode implemented by Professor Jungang Duo,which is promoted and tested in Heilongjiang University of Finance and Economics since 2022.The teaching mode meets the needs of application-oriented professional personnel training,and is compatible with local undergraduate colleges in terms of educational positioning,development strategic objectives,and teaching reform.It plays an important role in promoting the teaching reform of application-oriented undergraduate colleges,which is discussed from three aspects:teaching idea,practical operation,and overall evaluation mechanism.

Exploration of Curriculum Reform in the Context of Digital Empowerment:Taking the“Class Management”Course in the Primary Education Major of Higher Vocational Normal School as an Example

In the era of digital empowerment,the digital reform of higher vocational courses has become an inevitable trend.To explore professional curriculum reform,this study takes the“Class Management”course in the primary education major of higher vocational teachers as the research object,analyzes the importance of digital empowerment to curriculum reform,and discusses the teaching of the“Class Management”course new model and content reform plan.Digital technology empowering traditional courses is a new trend,which is both an opportunity and a challenge.This study aims to explore the application of digital technology in courses and provide certain guidelines for curriculum reform in the field of education.