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.

Chinese medical service and medical education in urgent need of reform in the context of public welfare-based medical reform

After six years＇medical reform,about 7.8 billion person-times of medical service has been achieved by2014,and the number of persons covered by basic medical insurance for urban employees,basic medical insurance for urban residents,and new rural cooperative medical insurance exceeded 1.3 billion,of which the coverage ratio reached as high as over 95%,establishing the largest basic medical security network in the world.

Review on Innovative Catalytic Reforming of Natural Gas to Syngas

Decreasing supplies of high quality crude oil and increasing demand for high quality distillates have motivated the interest in converting natural gas to liquid fuels, especially with the present boom in natural gas proven reserves. Nevertheless, one major issue is the curtailment of costs incurred in producing synthesis gas from natural gas, which account for approximately 60% of the costs used in producing liquid fuels. While there are three main routes to convert natural gas to syngas: steam reforming (SMR), partial Oxidation (POX) and auto-thermal reforming (ATR). Significant new developments and improvements in these technologies, established innovative processes to minimize greenhouse gases emission, minimize energy consumption, enhance syngas processes, adjust the desired H2/CO ratio and change the baseline economics. This article reviews the state of the art for the reforming of natural gas to synthesis gas taking into consideration all the new innovations in both processes and catalysis.

Thermodynamic analysis of mixed and dry reforming of methane for solar thermal applications

Thermodynamic analysis of the reforming of methane with carbon dioxide alone （＂dry reforming＂） and with carbon dioxide and steam together （＂mixed reforming＂） is performed as part of a project which investigates the suitability of these endothermic reactions for the storage of solar thermal energy. The Gibbs free energy minimization method was employed to identify thermodynamically optimal operating conditions for dry reforming as well as mixed reforming with a desired H2/CO molar ratio of 2. The non-stoichiometric equilibrium model was developed using FactSage software to conduct the thermodynamic calculations for carbon formation, H2/CO ratio, CH4 conversion and H2 yield as a function of reaction temperature, pressure and reactant molar ratios. Thermodynamic calculations demonstrate that in the mixed reforming process, optimal operating conditions in a carbon-free zone are under H2O/CH4 /CO2 =1.0/1.0/0.5, p = 1 to 10 bar and T = 800 to 850℃ for the production of syngas with a H2 /CO molar ratio of 2. Under the optimal conditions, the maximum H2 yield of 88.0% is achieved at 1 bar and 850℃ with a maximum CH4 conversion of 99.3%. In the dry reforming process, a carbon formation regime is always present at a CO2/CH4 molar ratio of 1 for T = 700 1000℃ and p = 1-30 bar, whereas a carbon-free regime can be obtained at a CO2/CH4 molar ratio greater than 1.5 and T≥800℃.

To Accomplish the Unaccomplished Reform： Lessons and Options of RMB Exchange Rate Reform

The exchange rate reform initiated on August 11,2015 is an important attempt by the PBoC to transform China's exchange rate regime from the "crawl-like arrangement" to a floating regime.However,after a three-day experiment,the PBoC abandoned the original goal of the reform.Since then,the central bank has implemented a new exchange rate-setting mechanism.Under this mechanism,the central parity of the renminbi(RMB) against the US dollar is decided by the arithmetic average of the RMB exchange rate that keeps the index of a currency basket unchanged over the past 24 hours and the previous day's closing price of USD/CNY.Due to the introduction of the index of a currency basket,additional uncertainty has been introduced into the determination of the RMB exchange rate,because of the uncertainty of the dollar index(USDX).As a result,to a certain extent,the one-way bet on the RMB expectations is weakened.However,the current exchange rate formation mechanism cannot reverse the trend of devaluation of the RMB,nor can it eliminate depreciation expectations.Meanwhile,it hinders the effectiveness of central bank's independent monetary policy based on the domestic economic fundamentals.And also,the "two-way float" created by the new price-setting mechanism is artificial and has led to significant losses of foreign exchange reserve.The paper explains how the new price-setting mechanism works,and identifies the important features of the mechanism and its pros and cons.The paper argues that despite some advantages,the new exchange rate regime as a soft peg regime is not sustainable and the PBoC should stop foreign exchange market intervention as soon as possible.We hope that the PBoC can learn the lessons from the failure of the "August 11 reform" and accomplish the unaccomplished reform in an urgent manner.

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.

China's 30-year Industrial Reform in Retrospect

Industrial reform in China truly embodies the rich content and hard experience of exploration along the path of socialism with Chinese characteristics. At the first stage of industrial reform,a thought revolution was started,which laid the foundation for the development of the market economy,i.e. "to get away from poverty,we have to help ourselves and pursue self-interests". Society then began to realize that the action of individuals and enterprises to pursue income,profit and wealth was not only a proper and rational behavior of discrete entities,but also a reasonable behavior bene cial to society. This profound thought revolution played a decisive role in the transformation from a planned to market economy. At the second stage of industrial reform,some bold assaults were launched on every aspect of the planned economy,while the socialist market economy was identified as the objective of system reform. In this process,Chinese industry courageously,boldly and confidently moved towards an open market economy. As a result,China can now proclaim to the world:"we are not afraid of market competition,but rather,we look forward to it!" At the third stage of industrial reform,the focus has shifted from resolving issues of the transition from a planned to market economy into addressing common institutional and policy issues facing countries worldwide with regard to the effective operation of the market economy. From then on,industrial reform in China was no longer the business of China alone,but the business of the whole world.

Profitability Analysis of Selected Steam Methane Reforming Methods for Hydrogen Production

One of the matured methods for producing hydrogen in bulk is steam methane reforming (SMR). The two commercial aspects of producing hydrogen from SMR are SMR with shift reactor (SR) and SMR with dry methane reforming (DRM). Although SMR with SR produces high hydrogen yield, it emits a large quantity of carbon dioxide (CO2). On the contrary, SMR and DRM produce low hydrogen yield but favorably emit a low quantity of CO2. However, it is not obvious which of these methods is more favourable economically. Consequently, using UNISIM Software Package, this study investigates three SMR methods namely SMR with SR, SMR with DRM and SMR with the combination of DRM and SR for the purpose of determining the most favourable route for producing hydrogen. This was done on the basis of feedstock rate of 100 kmol/hr of methane which reacted with 250 kmol/hr of steam for 8000 hrs annually using the rate of CO2 and CO emissions (COx) and the plant net profit percentage as performance indices. The profitability analysis shows that SMR/SR process is the most profitable process with a net profit percentage of 41.3%. Moreover, SMR/SR process has the highest yield and interestingly lowest COx emission rate. It is therefore concluded that the most favourable process route, technically and economically, is SMR/SR for the production of hydrogen using methane as feedstock.

Cyclical Patterns of China’s Reform and Their Implications for the New Era

After taking stock of China's four-decade reforms, this paper identifies the cyclical patterns of China's reforms, which consist of an intermediate cycle and three short cycles. The purpose of reform is to adjust the changing relations of production to changing productivity. China has adopted a gradualist approach of reform, and reform cycles have coincided with economic cycles. The cyclical changes of reform are of great significance to comprehensively deepening reforms in the new era: Downward pressures of the economy present the best window period for reform;a new cycle of reform will unveil a new economic cycle as well;the people's support is essential to pushing forward the cyclical movements of reform;and top-down design is essential to deepen reforms on all fronts.

农村宅基地制度改革的现实需求、主要困境与应对策略

基于江西省农村宅基地制度改革实践经验,采用演绎归纳法分析农村宅基地制度改革的现实需求和面临的主要困境,并提出应对策略,为稳慎推进农村宅基地制度改革、促进乡村振兴提供实践参考。结果表明:1)农村宅基地制度改革有助于策应“三产融合”发展用地保障、农村人居环境改善、新时代文明乡风建设、农村社会治理提升等多维现实需求。2)改革面临村庄差异难以形成可推广的统一模式,村集体自组织能力偏弱使得改革内生动力形成难,政策稳定性不足导致宅基地历史问题处置难,退出宅基地再次利用优势不足使得闲置宅基地盘活难等现实困境。据此,深化农村宅基地制度改革,应坚持需求导向、系统思维、农民主体地位,以及先立后破的原则,对待历史遗留问题保持历史耐心,充分发挥村民的主人翁精神,把农村宅基地制度改革与乡村振兴战略融合,因村施策精准推进。

地方改革试点的实践样态与行动逻辑--基于“激励-问责”协同性框架的多案例分析

改革试点是一种重要的治国理政机制。中国的改革试点不仅是一种纵向的分级制政策实验,在横向上地方改革试点还表现出明显的地方性差异。改革试点对应的是宽泛的政策指导与政策的灵活性,政策执行的条件将直接影响地方改革效能。在地方改革试点中,激励结构与问责力度是影响政策执行的两个关键要素。基于全国农村产权制度改革的多案例研究结果表明,地方政府的激励结构、问责强度和资源禀赋构成了地方改革试点的使动条件,地方主政者的行动态度、行动空间和行动能力构成了地方改革试点的能动条件,两者协同促使地方政府采取争先创新、稳妥有序、应付避责与象征执行的行动策略。因此,在地方改革试点中,要营造更具包容性的政策环境,建立相对均衡的制度结构,激发地方改革创新的积极性和能动性,以提升地方治理效能。

新一轮机构改革的研究进展与未来展望

2023年新一轮机构改革是一场锚定中国式现代化的重要改革。既有研究阐释了改革的新特征,揭示了历次改革的演进逻辑,并阐明了自主性机构改革的基本行动路径,即调整结构、转变职能、理顺关系。未来研究可以沿着自主知识体系和“两个结合”的思路进一步拓展,重点关注规范议事协调机构、加快数字政府建设、厘清纵向职责划分、推进事业单位改革并保障机构改革实效。

革命传统“进高考”的理据、价值与原则——以高考语文为例

推动革命传统教育加快进入新课程、新教材,需要与各个学科评价的内在需求相结合,在高考内容改革中有所反映。以高考语文科为例展开讨论,在明晰革命传统“进高考”的政策和学理依据基础上,提出高考语文融入革命传统教育内容,具有为落实立德树人根本任务提供有效载体、重构革命文化融入课程体系的行动路径、实现革命文化思想内涵与情感价值的具象建构等独特的价值意蕴,进而提出以侧重缘文悟道、注重思维考查、引导知行统一为“进高考”的三大基本原则。

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.

高职院校“三教”改革协同机制探索

以协同学为理论基础,分析高职院校“三教”改革协同机制构建的必要性,探索高职院校“三教”改革协同机制构建的路径,建立改革理念认同机制、政策或制度协同机制、环境协同机制,提升人才培养质量。

“三高三难”背景下职业院校虚拟仿真实训改革初探

高职教育的高质量发展,需要进行实训教学改革来解决当前实训存在的“高投入高难度高风险、难实施难观摩难再现”问题。虚拟仿真实训改革应结合教学实际、企业生产、区域发展,以现有实训基地建设为基础,以多种信息技术为手段,聚焦行业需求,搭建企业和学生双向需求通道,科学构建实训课程评价体系,整合校企课程资源,构建共建共享共用机制,实现大范围资源共享,最终实现高技能人才培养的信息化、智能化和现代化的目标。

我国宅基地制度改革试点的演进逻辑与路径优化

宅基地制度改革是中国农村土地制度改革的重要内涵,是实施乡村振兴战略的重要举措。本文基于中国特色改革试点一般性模式,构建宅基地制度改革试点的分析框架,探析党的十八届三中全会以来两轮宅基地制度改革试点的基本逻辑、主要成效与未来路径。研究显示,一方面,遵循“目标制定—顶层设计—地方试点—成果总结”的一般模式,两轮宅基地制度改革试点明晰了“三权分置”的产权结构,形成了权责统一的所有权行使机制、多元化的资格权保障机制和因地制宜的使用权放活机制;另一方面,改革试点仍然面临着集体所有权主体认定不明晰、资格权认定口径不一、使用权放活机制存在缺陷等问题,难以适应中国式现代化进程中改善土地资源配置、推动乡村振兴的要求。未来,改革应坚持保障农民和农村集体组织利益、改进乡村治理能力和撬动要素联动配置三项基本取向,从加强制度改革系统性、央地联动性、地区与部门协调性三个维度出发,进一步推动宅基地制度改革试点,以期形成成熟经验,更好推动农业农村现代化进程。

职业技能竞赛背景下的单片机技术课程教学改革研究

对职业技能竞赛背景下的单片机技术课程教学改革进行了研究,探索了如何通过课程改革提高学生的技能水平和职业素养。首先分析了现有单片机技术课程的问题,包括教学内容过于抽象、理论知识与实践能力脱节等方面,然后提出了改革的思路和方法。具体来说,通过优化教学内容、改进教学方法、实施竞赛培训等手段,使学生能够更好地掌握单片机技术的基本原理和应用技巧,增强实践能力和创新意识,培养职业素养和团队协作精神。最后,通过实践教学,验证了课程改革的有效性和可行性,取得了一定的成果和效果。该研究成果可为其他相关领域的教学改革提供参考和借鉴。

高职院校“三课”改革的实践探索

“三教”改革是高职院校教学改革的重要内容,如何深化“三教”改革,提升教学质量,是高职教育增强适应性,高职院校提升关键办学能力,实现高质量发展的核心问题。文章坚持问题导向和成果导向,结合实践探索,创新性提出以教师主导的“三课”(课程、课堂、课业)改革为抓手,推进“三教”改革的策略,深刻分析了“三课”改革的动因,深入探讨了“三课”改革的目标、原则、内容和方法,为高职院校深化“三教”改革提供了新思路。

“三教改革”背景下高职院校市场营销专业人才培养模式改革实践——以安徽工贸职业技术学院为例

职业教育改革背景下,“三教”改革成为职业教育人才培养与评价改革的核心内容。安徽工贸职业技术学院实践“三教”改革,形成“校企合作,能力为上”的新人才培养模式。依据岗位职业能力要求重构课程体系、更新教学资源,丰富教学方式方法,改革考核评价机制。同时,强化教师队伍建设、深化校企合作,保障“三教”改革质量。