Through reviewing different development phases of transportation and communication facilities as well as their profound influence on the evolution of urban spatial pattern,it was disclosed that the development and imp...Through reviewing different development phases of transportation and communication facilities as well as their profound influence on the evolution of urban spatial pattern,it was disclosed that the development and improvement of information network communication would bring fundamental transformation of urban basic functions which would take effect through the usage of urban land,and finally lead to the spatial pattern reform of the whole city.展开更多
Methanol is regarded as an important liquid fuel for hydrogen storage, transportation, and in-situ generation due to its convenient conveyance, high energy density, and low conversion temperature. In this work, an ove...Methanol is regarded as an important liquid fuel for hydrogen storage, transportation, and in-situ generation due to its convenient conveyance, high energy density, and low conversion temperature. In this work, an overview of state-of-the-art investigations on methanol reforming is critically summarized, including the detailed introduction of methanol conversion pathways from the perspective of fuel cell applications, various advanced materials design for catalytic methanol conversion, as well as the development of steam methanol reformers. For the section of utilization pathways, reactions such as steam reforming of methanol, partial oxidation of methanol, oxidative steam reforming of methanol, and sorption-enhanced steam methanol reforming were elaborated;For the catalyst section, the strategies to enhance the catalytic activity and other comprehensive performances were summarized;For the reactor section, the newly designed steam methanol reformers were thoroughly described. This review will benefit researchers from both fundamental research and fuel cell applications in the field of catalyzing methanol to hydrogen.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
This article aims to investigate the transient behavior of a planar direct internal reforming solid oxide fuel cell (DIR-SOFC) comprehensively. A one-dimensional dynamic model of a planar D1R-SOFC is first developed...This article aims to investigate the transient behavior of a planar direct internal reforming solid oxide fuel cell (DIR-SOFC) comprehensively. A one-dimensional dynamic model of a planar D1R-SOFC is first developed based on mass and energy balances, and electrochemical principles. Further, a solution strategy is presented to solve the model, and the International Energy Agency (IEA) benchmark test is used to validate the model. Then, through model-based simulations, the steady-state performance of a co-flow planar DIR-SOFC under specified initial operating conditions and its dynamic response to introduced operating parameter disturbances are studied. The dynamic responses of important SOFC variables, such as cell temperature, current density, and cell voltage are all investigated when the SOFC is subjected to the step-changes in various operating parameters including both the load current and the inlet fuel and air flow rates. The results indicate that the rapid dynamics of the current density and the cell voltage are mainly influenced by the gas composition, particularly the H2 molar fraction in anode gas channels, while their slow dynamics are both dominated by the SOLID (including the PEN and interconnects) temperature. As the load current increases, the SOLID temperature and the maximum SOLID temperature gradient both increase, and thereby, the cell breakdown is apt to occur because of excessive thermal stresses. Changing the inlet fuel flow rate might lead to the change in the anode gas composition and the consequent change in the current density distribution and cell voltage. The inlet air flow rate has a great impact on the cell temperature distribution along the cell, and thus, is a suitable manipulated variable to control the cell temperature.展开更多
Copper-indium-gallium-diselenide(CIGS)is a fast-evolving commercial solar cell.The firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGS solar cell recycling.In...Copper-indium-gallium-diselenide(CIGS)is a fast-evolving commercial solar cell.The firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGS solar cell recycling.In this paper,the sources and characteristics of valuable metals in spent CIGS solar cells were reviewed.The potential environmental impacts of CIGS,including service life,critical material,and material toxicity,were outlined.The main recovery methods of valuable metals in the various types of spent CIGS,including hydrometallurgy,pyrometallurgy,and comprehensive treatment processes,were compared and discussed.The mechanism of different recovery processes was summarized.The challenges faced by different recycling processes of spent CIGS were also covered in this review.Finally,the economic viability of the recycling process was assessed.The purpose of this review is to provide reasonable suggestions for the sustainable development of CIGS and the harmless disposal of spent CIGS.展开更多
New and distinctive regions of economic interaction and growth, known as Extended Metropolitan Regions (EMRs), are emerging in China. This paper will examine the role of the various levels of the Chinese governments a...New and distinctive regions of economic interaction and growth, known as Extended Metropolitan Regions (EMRs), are emerging in China. This paper will examine the role of the various levels of the Chinese governments and their administrative reforms in the development of one of the urbanising regions in China: the Shenyang Dalian EMR, Liaoning Province. It is primarily concerned with to what extent EMR's spatial growth pattern is influenced by governmental policies and how the changes in administrative boundaries have impacted rural urban relations.展开更多
Cu/ZnAlO catalysts derived from hydroxycarbonate precursors containinghydrotalcite-like layered double hydroxides (LDHs) were studied. The influence on the performanceof the catalysts was also studied when the Al in t...Cu/ZnAlO catalysts derived from hydroxycarbonate precursors containinghydrotalcite-like layered double hydroxides (LDHs) were studied. The influence on the performanceof the catalysts was also studied when the Al in the Cu/ZnAlO catalyst was partly or completelyreplaced by Zr or Ce.展开更多
In view of artificially high urbanization rate of China and possible causes,survey and data analysis methods were used to discuss reform of household registration system,and path for promoting rural land system reform...In view of artificially high urbanization rate of China and possible causes,survey and data analysis methods were used to discuss reform of household registration system,and path for promoting rural land system reform. Results show that it is required to eliminate bottlenecks of land system in the advance of new urbanization process. In line with land system bottlenecks of new urbanization,it is recommended to take following measures.( i) Promoting land right confirmation centered land system reform.( ii) Weakening rural land ownership and stressing land use right.( iii) Establishing urban and rural integrated land market and putting an end to low cost urbanization road.( iv) Realizing asset value of rural construction land and tackling the problem of insufficient construction land.( v) Reforming the land expropriation system and increasing the share of gain in land value to farmers.( vi) Implementing different land policies to promote coordinated development of regional social economy.( vii) Establishing land circulation access system to ensure unchanged land use purpose and high efficient use.展开更多
After a trial period between 2008 and 2010, the LTRP (Land Tenure Regularization Program) was implemented in Rwanda. The program is the consequent implementation of the National Land Policy (2004), which initiated...After a trial period between 2008 and 2010, the LTRP (Land Tenure Regularization Program) was implemented in Rwanda. The program is the consequent implementation of the National Land Policy (2004), which initiated the reform of the administration of land. With the LTRP, titles to land were registered in the name of every landholder to unlock the potentialities for sustainable growth based on a clear framework, equally valid to all landholders. This paper describes the changes in land and property market activity after the reforms and comments on increasing development pressure on land which can be observed. It recalls that this new market activity is intended and policy-made as a result of the Land Policy with the land tenure regularization and changed land tenure principles, the EDPRS2 which clearly focuses on enabling the private sector to participate in and drive economic development, and the new urbanization agenda coming with the Vision 2020 and the EDPRS2. Identified factors are also discussed which contribute to the new market values of land and a case study in Kigali is referenced which identified accessibility to an area as the most influencing factor, besides access to services and levels of investment on the land. The importance is now, to keep ensuring and enhancing the positive impact of the policy directions in a sustainable manner for their maximum positive impact on socio-economic progress. Provided are recommendations of how to strategically guide public policies and investment in support of sustainable land market activity and using geospatial technologies. The supportive application of technologies is explored.展开更多
A detailed mathematical model of a direct internal reforming solid oxide fuel cell(DIR-SOFC) incorporating with simulation of chemical and physical processes in the fuel cell is presented. The model is developed based...A detailed mathematical model of a direct internal reforming solid oxide fuel cell(DIR-SOFC) incorporating with simulation of chemical and physical processes in the fuel cell is presented. The model is developed based on the reforming and electrochemical reaction mechanisms,mass and energy conservation,and heat transfer. A computational fluid dynamics(CFD) method is used for solving the complicated multiple partial differential equations(PDEs) to obtain the numerical approximations. The resulting distributions of chemical species concentrations,temperature and current density in a cross-flow DIR-SOFC are given and analyzed in detail. Further,the influence between distributions of chemical species concentrations,temperature and current density during the simulation is illustrated and discussed. The heat and mass transfer,and the kinetics of reforming and electrochemical reactions have significant effects on the parameter distributions within the cell. The results show the particular characteristics of the DIR-SOFC among fuel cells,and can aid in stack design and control.展开更多
The 19th century was a milestone for urban planning history of the Eastern Mediterranean region since the typology of the Ottoman city was reformed,more or less abruptly,by strong Western European influences as a cons...The 19th century was a milestone for urban planning history of the Eastern Mediterranean region since the typology of the Ottoman city was reformed,more or less abruptly,by strong Western European influences as a consequence of broader political,economic,and social transformations.From the very beginning of the 19th century,the Ottoman state confronted significant administrative issues that raised in the importance to institutionalise reforms over a long period of time,representing the foundation of later urban“modernisation reforms”.These challenges of the Ottoman cities at that period coincided with one crucial reform framework known as“Tanzimat”,which reflected the social willingness to inherit elements of European culture,technological innovations,and lifestyle.According to that direction,urban space was considered as a workshop of planning regulations and reforms adopting principles of contemporary,at that time,European urban planning,mostly applied in England and France.These social and urban reforms established by the Ottoman state marked the first attempt to relate Ottoman cities with European planning,urban infrastructures,building regulations,and public administration.During the period of Tanzimat(1839-1876),the economic role and impact of cities was strengthened reflecting a rising urbanisation of population.This article highlights this“Europeanisation”of Ottoman cities at the period of Tanzimat by investigating five case-study cities:Smyrna,Beirut,Alexandria,Thessaloniki,and Constantinople.All these cities were important ports-hubs of the Eastern Mediterranean whose urban development since the 1840s was a direct consequence of the modernisation reforms and,in general,an increase of European influence.These urban reforms,like in many European cities,included new transport infrastructures and communication networks,public services(water,gas,tramways,etc.),health and education,and new industrial patterns.展开更多
Thermal management in solid oxide fuel cells(SOFC)is a critical issue due to non-uniform electrochemical reactions and convective fl ows within the cells.Therefore,a 2D mathematical model is established herein to inve...Thermal management in solid oxide fuel cells(SOFC)is a critical issue due to non-uniform electrochemical reactions and convective fl ows within the cells.Therefore,a 2D mathematical model is established herein to investigate the thermal responses of a tubular methanol-fueled SOFC.Results show that unlike the low-temperature condition of 873 K,where the peak temperature gradient occurs at the cell center,it appears near the fuel inlet at 1073 K because of the rapid temperature rise induced by the elevated current density.Despite the large heat convection capacity,excessive air could not eff ectively eliminate the harmful temperature gradient caused by the large current density.Thus,optimal control of the current density by properly selecting the operating potential could generate a local thermal neutral state.Interestingly,the maximum axial temperature gradient could be reduced by about 18%at 973 K and 20%at 1073 K when the air with a 5 K higher temperature is supplied.Additionally,despite the higher electrochemical performance observed,the cell with a counter-fl ow arrange-ment featured by a larger hot area and higher maximum temperature gradients is not preferable for a ceramic SOFC system considering thermal durability.Overall,this study could provide insightful thermal information for the operating condition selection,structure design,and stability assessment of realistic SOFCs combined with their internal reforming process.展开更多
Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio...Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.展开更多
In China, household registration system has the problems of unreasonable standard setting and relevant supporting measures failure to keep pace with the development trend. From analysis of current problems and situati...In China, household registration system has the problems of unreasonable standard setting and relevant supporting measures failure to keep pace with the development trend. From analysis of current problems and situations, it is believed that household registration system should undertake reform and take a new road by means of informationization. Strengthening informationization management in land, population, education and labor market can better perform urban and rural integration.展开更多
Balancing urban and rural comprehensive reform is the major reform and developmental strategy of China. On the basis of the concept and theory of balancing rural and urban reform, the two national pilot cities Chengdu...Balancing urban and rural comprehensive reform is the major reform and developmental strategy of China. On the basis of the concept and theory of balancing rural and urban reform, the two national pilot cities Chengdu, Chongqing and several provincial pilot cities including Ningbo, Yangzhou, Shaoxing and Zigong are compared. The experiences and connotation of balancing urban and rural areas are concluded from the following four aspects. Firstly, scientific plan is a prerequisite; secondly, promoting "three collections" is the core; thirdly, developing people's livelihood is the basis; fourthly, organization security is the key.展开更多
文摘Through reviewing different development phases of transportation and communication facilities as well as their profound influence on the evolution of urban spatial pattern,it was disclosed that the development and improvement of information network communication would bring fundamental transformation of urban basic functions which would take effect through the usage of urban land,and finally lead to the spatial pattern reform of the whole city.
基金Project(51876224)supported by the National Natural Science Foundation of ChinaProject(2020CX008)supported by the Innovation-Driven Project of Central South University,China。
文摘Methanol is regarded as an important liquid fuel for hydrogen storage, transportation, and in-situ generation due to its convenient conveyance, high energy density, and low conversion temperature. In this work, an overview of state-of-the-art investigations on methanol reforming is critically summarized, including the detailed introduction of methanol conversion pathways from the perspective of fuel cell applications, various advanced materials design for catalytic methanol conversion, as well as the development of steam methanol reformers. For the section of utilization pathways, reactions such as steam reforming of methanol, partial oxidation of methanol, oxidative steam reforming of methanol, and sorption-enhanced steam methanol reforming were elaborated;For the catalyst section, the strategies to enhance the catalytic activity and other comprehensive performances were summarized;For the reactor section, the newly designed steam methanol reformers were thoroughly described. This review will benefit researchers from both fundamental research and fuel cell applications in the field of catalyzing methanol to hydrogen.
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Supported by the National High Technology Research and Development Program of China (2006AA05Z148)
文摘This article aims to investigate the transient behavior of a planar direct internal reforming solid oxide fuel cell (DIR-SOFC) comprehensively. A one-dimensional dynamic model of a planar D1R-SOFC is first developed based on mass and energy balances, and electrochemical principles. Further, a solution strategy is presented to solve the model, and the International Energy Agency (IEA) benchmark test is used to validate the model. Then, through model-based simulations, the steady-state performance of a co-flow planar DIR-SOFC under specified initial operating conditions and its dynamic response to introduced operating parameter disturbances are studied. The dynamic responses of important SOFC variables, such as cell temperature, current density, and cell voltage are all investigated when the SOFC is subjected to the step-changes in various operating parameters including both the load current and the inlet fuel and air flow rates. The results indicate that the rapid dynamics of the current density and the cell voltage are mainly influenced by the gas composition, particularly the H2 molar fraction in anode gas channels, while their slow dynamics are both dominated by the SOLID (including the PEN and interconnects) temperature. As the load current increases, the SOLID temperature and the maximum SOLID temperature gradient both increase, and thereby, the cell breakdown is apt to occur because of excessive thermal stresses. Changing the inlet fuel flow rate might lead to the change in the anode gas composition and the consequent change in the current density distribution and cell voltage. The inlet air flow rate has a great impact on the cell temperature distribution along the cell, and thus, is a suitable manipulated variable to control the cell temperature.
基金financially supported by the Beijing Natural Science Foundation of China (No. 2232038)the National Natural Science Foundation of China (Nos. 52034002 and U1802253)the Fundamental Research Funds for the Central Universities (No. FRF-TT-19-001)
文摘Copper-indium-gallium-diselenide(CIGS)is a fast-evolving commercial solar cell.The firm demand for global carbon reduction and the rise of potential environmental threats necessitate spent CIGS solar cell recycling.In this paper,the sources and characteristics of valuable metals in spent CIGS solar cells were reviewed.The potential environmental impacts of CIGS,including service life,critical material,and material toxicity,were outlined.The main recovery methods of valuable metals in the various types of spent CIGS,including hydrometallurgy,pyrometallurgy,and comprehensive treatment processes,were compared and discussed.The mechanism of different recovery processes was summarized.The challenges faced by different recycling processes of spent CIGS were also covered in this review.Finally,the economic viability of the recycling process was assessed.The purpose of this review is to provide reasonable suggestions for the sustainable development of CIGS and the harmless disposal of spent CIGS.
文摘New and distinctive regions of economic interaction and growth, known as Extended Metropolitan Regions (EMRs), are emerging in China. This paper will examine the role of the various levels of the Chinese governments and their administrative reforms in the development of one of the urbanising regions in China: the Shenyang Dalian EMR, Liaoning Province. It is primarily concerned with to what extent EMR's spatial growth pattern is influenced by governmental policies and how the changes in administrative boundaries have impacted rural urban relations.
基金Financial support from Guangdong Provincial Natural Science Foundation of China (000435), the Doctoral Program Foun- dation of the Ministry of Education (20010561003) Guangzhou Municipal Science and Technology project (2001J1-C0211).
文摘Cu/ZnAlO catalysts derived from hydroxycarbonate precursors containinghydrotalcite-like layered double hydroxides (LDHs) were studied. The influence on the performanceof the catalysts was also studied when the Al in the Cu/ZnAlO catalyst was partly or completelyreplaced by Zr or Ce.
基金Supported by Project of Anhui Development and Reform Commission "Study on Reform and Innovation of Rural Land System in Anhui Province"(20141121)
文摘In view of artificially high urbanization rate of China and possible causes,survey and data analysis methods were used to discuss reform of household registration system,and path for promoting rural land system reform. Results show that it is required to eliminate bottlenecks of land system in the advance of new urbanization process. In line with land system bottlenecks of new urbanization,it is recommended to take following measures.( i) Promoting land right confirmation centered land system reform.( ii) Weakening rural land ownership and stressing land use right.( iii) Establishing urban and rural integrated land market and putting an end to low cost urbanization road.( iv) Realizing asset value of rural construction land and tackling the problem of insufficient construction land.( v) Reforming the land expropriation system and increasing the share of gain in land value to farmers.( vi) Implementing different land policies to promote coordinated development of regional social economy.( vii) Establishing land circulation access system to ensure unchanged land use purpose and high efficient use.
文摘After a trial period between 2008 and 2010, the LTRP (Land Tenure Regularization Program) was implemented in Rwanda. The program is the consequent implementation of the National Land Policy (2004), which initiated the reform of the administration of land. With the LTRP, titles to land were registered in the name of every landholder to unlock the potentialities for sustainable growth based on a clear framework, equally valid to all landholders. This paper describes the changes in land and property market activity after the reforms and comments on increasing development pressure on land which can be observed. It recalls that this new market activity is intended and policy-made as a result of the Land Policy with the land tenure regularization and changed land tenure principles, the EDPRS2 which clearly focuses on enabling the private sector to participate in and drive economic development, and the new urbanization agenda coming with the Vision 2020 and the EDPRS2. Identified factors are also discussed which contribute to the new market values of land and a case study in Kigali is referenced which identified accessibility to an area as the most influencing factor, besides access to services and levels of investment on the land. The importance is now, to keep ensuring and enhancing the positive impact of the policy directions in a sustainable manner for their maximum positive impact on socio-economic progress. Provided are recommendations of how to strategically guide public policies and investment in support of sustainable land market activity and using geospatial technologies. The supportive application of technologies is explored.
基金Project (No. 2006AA05Z148) supported by the Hi-Tech Research and Development Program (863) of China
文摘A detailed mathematical model of a direct internal reforming solid oxide fuel cell(DIR-SOFC) incorporating with simulation of chemical and physical processes in the fuel cell is presented. The model is developed based on the reforming and electrochemical reaction mechanisms,mass and energy conservation,and heat transfer. A computational fluid dynamics(CFD) method is used for solving the complicated multiple partial differential equations(PDEs) to obtain the numerical approximations. The resulting distributions of chemical species concentrations,temperature and current density in a cross-flow DIR-SOFC are given and analyzed in detail. Further,the influence between distributions of chemical species concentrations,temperature and current density during the simulation is illustrated and discussed. The heat and mass transfer,and the kinetics of reforming and electrochemical reactions have significant effects on the parameter distributions within the cell. The results show the particular characteristics of the DIR-SOFC among fuel cells,and can aid in stack design and control.
文摘The 19th century was a milestone for urban planning history of the Eastern Mediterranean region since the typology of the Ottoman city was reformed,more or less abruptly,by strong Western European influences as a consequence of broader political,economic,and social transformations.From the very beginning of the 19th century,the Ottoman state confronted significant administrative issues that raised in the importance to institutionalise reforms over a long period of time,representing the foundation of later urban“modernisation reforms”.These challenges of the Ottoman cities at that period coincided with one crucial reform framework known as“Tanzimat”,which reflected the social willingness to inherit elements of European culture,technological innovations,and lifestyle.According to that direction,urban space was considered as a workshop of planning regulations and reforms adopting principles of contemporary,at that time,European urban planning,mostly applied in England and France.These social and urban reforms established by the Ottoman state marked the first attempt to relate Ottoman cities with European planning,urban infrastructures,building regulations,and public administration.During the period of Tanzimat(1839-1876),the economic role and impact of cities was strengthened reflecting a rising urbanisation of population.This article highlights this“Europeanisation”of Ottoman cities at the period of Tanzimat by investigating five case-study cities:Smyrna,Beirut,Alexandria,Thessaloniki,and Constantinople.All these cities were important ports-hubs of the Eastern Mediterranean whose urban development since the 1840s was a direct consequence of the modernisation reforms and,in general,an increase of European influence.These urban reforms,like in many European cities,included new transport infrastructures and communication networks,public services(water,gas,tramways,etc.),health and education,and new industrial patterns.
基金by the Project of Strategic Importance Funding Scheme from The Hong Kong China Polytechnic University(No.P0035168)the National Natural Science Foundation of China(No.51806241).
文摘Thermal management in solid oxide fuel cells(SOFC)is a critical issue due to non-uniform electrochemical reactions and convective fl ows within the cells.Therefore,a 2D mathematical model is established herein to investigate the thermal responses of a tubular methanol-fueled SOFC.Results show that unlike the low-temperature condition of 873 K,where the peak temperature gradient occurs at the cell center,it appears near the fuel inlet at 1073 K because of the rapid temperature rise induced by the elevated current density.Despite the large heat convection capacity,excessive air could not eff ectively eliminate the harmful temperature gradient caused by the large current density.Thus,optimal control of the current density by properly selecting the operating potential could generate a local thermal neutral state.Interestingly,the maximum axial temperature gradient could be reduced by about 18%at 973 K and 20%at 1073 K when the air with a 5 K higher temperature is supplied.Additionally,despite the higher electrochemical performance observed,the cell with a counter-fl ow arrange-ment featured by a larger hot area and higher maximum temperature gradients is not preferable for a ceramic SOFC system considering thermal durability.Overall,this study could provide insightful thermal information for the operating condition selection,structure design,and stability assessment of realistic SOFCs combined with their internal reforming process.
基金supported by the National Natural Science Foundation of China(Nos.61805257,41905130)in part by the China Postdoctoral Science Foundation(Nos.2020M671383,2020M681517)in part by the Science and Technology Development Plan Foundation of Suzhou(No.SS202148).
文摘Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.
基金Supported by Key Project of National Soft Science Research Plan (Grant No.:2011GXS1D003 )Key Project of Soft Science Research Plan of Chongqing Municipality (Grant No.:cstc2011cx-rkxB00008)
文摘In China, household registration system has the problems of unreasonable standard setting and relevant supporting measures failure to keep pace with the development trend. From analysis of current problems and situations, it is believed that household registration system should undertake reform and take a new road by means of informationization. Strengthening informationization management in land, population, education and labor market can better perform urban and rural integration.
基金Supported by Social Science Plan Project of Zigong City,Sichuan Province (2010Y-01)
文摘Balancing urban and rural comprehensive reform is the major reform and developmental strategy of China. On the basis of the concept and theory of balancing rural and urban reform, the two national pilot cities Chengdu, Chongqing and several provincial pilot cities including Ningbo, Yangzhou, Shaoxing and Zigong are compared. The experiences and connotation of balancing urban and rural areas are concluded from the following four aspects. Firstly, scientific plan is a prerequisite; secondly, promoting "three collections" is the core; thirdly, developing people's livelihood is the basis; fourthly, organization security is the key.