A rescuing archaeological excavation in Area H of the Hutian kiln-site was carried out in July-October 1999 by the Jiangxi Provincial Institute of Cultural Relics and Archaeology. The work covered an area of more than...A rescuing archaeological excavation in Area H of the Hutian kiln-site was carried out in July-October 1999 by the Jiangxi Provincial Institute of Cultural Relics and Archaeology. The work covered an area of more than 1,300 sq m, revealed 11 spots of house-foundation, well, small yard,clay-refining pool and ash-pit remains, and discovered above 600 intact and restorable articles of greenish-white-glazed, egg-white-glazed, black-glazed and blue-and-white porcelain wares from the Song, Yuan and Ming periods. The excavation clarified relatively direct stratigraphic evidence on the typological evolution of the vessels typical of the Song and Yuan periods and threw light on a batch of egg-white-glazed “shu fu” porcelain objects of the early Yuan and some inscribed porcelain-making implements.展开更多
A sequential design and global optimization method is proposed to coordinately design local and widearea controllers to enhance the overall stability of largescale power system.The sequential design is used to assign ...A sequential design and global optimization method is proposed to coordinately design local and widearea controllers to enhance the overall stability of largescale power system.The sequential design is used to assign the distributed local power system stabilizer (LPSS) and high-voltage direct current (HVDC) wide-area stabilizing controller (HVDC-WASC) to the concerned damping modes.The global optimization is used to simultaneously optimize all the overall control gains of LPSSs and HVDCWASC.Moreover,the optimization model,which has an adaptive ability of searching and updating dominant oscillation modes,is established.Both the linear analysis and nonlinear simulation results verify the effectiveness of the proposed design method in enhancing the stability of large-scale power systems.展开更多
Energy conservation and emissions reduction have become increasingly significant for automobiles due to the severity of the current energy situation.Hybrid electric vehicle(HEV)technology is one of the most promising ...Energy conservation and emissions reduction have become increasingly significant for automobiles due to the severity of the current energy situation.Hybrid electric vehicle(HEV)technology is one of the most promising solutions.This study investigated the total efficiency of a HEV powertrain.To improve the total efficiency,the engine should be regulated to work at its highest efficiency and drive the wheels directly as much as possible.To accomplish this,we developed an energy management strategy based on the direct drive area(DDA)of the engine’s efficiency map.Several typical HEV models were built to compare the fuel consumption using DDA and rule-based strategies.Furthermore,the function of the HEV transmission system with DDA was considered.The transmission in a HEV should regulate the engine to work at its highest efficiency as much as possible,which is rather different than the regulation in an internal combustion engine vehicle.The functional change may lead to transmission systems with fewer gears but optimal gear ratios.If this trend is realized,the manufacturing cost of HEVs could be largely reduced.展开更多
A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach inv...A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach involving Resistivity and IP methods. This investigation was allowed to collect data on forty-five (45) profiling lines at three acquisition levels (AB = 100 m, MN = 10 m;AB = 200 m, MN = 20 m and AB = 500 m, MN = 50 m) and two electric panels L1 and L4, using the Schlumberger array. Processing, modeling and interpretation of data collected using the Winsev, Res2Dinv and Surfer software helped in highlighting a conductive and strongly mineralized discontinuity in granite formations, which lined up with the NE-SW Kadei tectonic line. It extends beyond 100 m depth over an average width of 600 m. The mineralization associated with this discontinuity is identified by a high concentration of disseminated metalliferous minerals in quartz or pegmatite veins. The mining reconnaissance works in the study area and those of several authors have characterized this anomaly to a lode gold quartz or large pegmatite. The results of this study correlate with geological and tectonic data for the region marked by NE-SW Kadei tectonic line. Therefore, they confirm the reliability of a geoelectrical DC investigation method combining Resistivity and IP to the identification of ore bodies.展开更多
A facile synthesis procedure is proposed to prepare homogeneous Zr and Ti co-doped SBA-15(Zr-Ti-SBA-15)with high specific surface area of 876.0m2 g−1.Based on“masking mechanism”from tanning,lactic acid was used as m...A facile synthesis procedure is proposed to prepare homogeneous Zr and Ti co-doped SBA-15(Zr-Ti-SBA-15)with high specific surface area of 876.0m2 g−1.Based on“masking mechanism”from tanning,lactic acid was used as masking agent to obtain the uniform distribution of Zr and Ti species in the SBA-15 framework.The obtained materials were characterized by powder X-ray diffraction(XRD),nitrogen adsorption-desorption isotherms,scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray photoelectron(XPS).The results reveal that in mesoporous materials,the presence of lactic acid gives rise to the uniform distribution of Zr and Ti species.The adsorption equilibrium and kinetic studies of Zr-Ti-SBA-15 materials show that the adsorption process conforms to the Langmuir isotherm and pseudo-second-order kinetic model,respectively.Regenerational experiments show that the Zr-Ti-SBA-15 displays a significant adsorption ability for methylene blue(MB)(up to 291.6 mg/g),along with good reusability,indicating promising potentials of commercialization.Methodologically,this work provides a wide range of possibilities for further development of SBA-15 based on bimetallic and sewage disposal.展开更多
For radiative direct exchange areas in three dimensional system, the Uniform Deterministic Discrete Method (UDDM) was adopted. The spherical surface dividing method for sending area element and the regular icosahedron...For radiative direct exchange areas in three dimensional system, the Uniform Deterministic Discrete Method (UDDM) was adopted. The spherical surface dividing method for sending area element and the regular icosahedron for sending volume element can meet with the direct exchange area computation of any kind of zone pairs. The numerical examples of direct exchange area in three dimensional system with nonhomogeneous attenuation coefficients indicated that the UDDM can give very high numerical accuracy.展开更多
ELECTROCORTICOGRAPHY (ECoG), the intraoperative recording of cortical potentials, has played an important role in the surgical management of patients with medically intractable epilepsy. This technique is useful in ep...ELECTROCORTICOGRAPHY (ECoG), the intraoperative recording of cortical potentials, has played an important role in the surgical management of patients with medically intractable epilepsy. This technique is useful in epilepsy surgery to delineate margins of epileptogenic zones, guide resection,展开更多
The dual-layer electrode for fuel cells is typically prepared by binding discrete catalyst nanoparticles onto a diffusion layer.Such a random packing forms a dense catalyst layer and thus creates a barrier for mass/io...The dual-layer electrode for fuel cells is typically prepared by binding discrete catalyst nanoparticles onto a diffusion layer.Such a random packing forms a dense catalyst layer and thus creates a barrier for mass/ion transport,particularly for direct liquid fuel cells.Three-dimensional porous electrodes,a thin nano-porous catalyst layer uniformly distributed on the matrix surface of a foam-like structure,are typically employed to improve the mass/ion transport.Such a three-dimensional porous structure brings two critical advantages:(i)reduced mass/ion transport resistance for the delivery of the reactants via shortening the transport distance and(ii)enlarged electrochemical surface area,via reducing the dead pores,isolated particles and severe aggregations,for interfacial reactions.Moreover,the three-dimensional design is capable of fabricating binder-free electrodes,thereby eliminating the use of ionomers/binders and simplifying the fabrication process.In this work,three types of three-dimensional porous electrode are fabricated,via different preparation methods,for direct formate fuel cells:(i)Pd/C nanoparticles coating on the nickel foam matrix surface(Pd-C/NF)via a dip-coating method,(ii)Pd nanoparticles depositing on the nickel foam matrix surface(Pd/NF)via reduction reaction deposition,and(iii)Pd nanoparticles embedding in the nickel foam matrix(Pd/(in)NF)via replacement reaction deposition.The latter two are binder-free three-dimensional porous electrodes.As a comparison,a conventional dual-layer design,Pd/C nanoparticles painting on the nickel foam layer(Pd-C//NF),is also prepared via direct painting method.It is shown that the use of the three-dimensional Pd-C/NF electrode as the anode in a direct formate fuel cell results in a peak power density of 45.0 mW cm^(-2)at 60℃,which is two times of that achieved by using a conventional dual-layer design(19.5 mW cm^(-2)).This performance improvement is mainly attributed to the unique three-dimensional structure design,which effectively enhances the mass/ion展开更多
文摘A rescuing archaeological excavation in Area H of the Hutian kiln-site was carried out in July-October 1999 by the Jiangxi Provincial Institute of Cultural Relics and Archaeology. The work covered an area of more than 1,300 sq m, revealed 11 spots of house-foundation, well, small yard,clay-refining pool and ash-pit remains, and discovered above 600 intact and restorable articles of greenish-white-glazed, egg-white-glazed, black-glazed and blue-and-white porcelain wares from the Song, Yuan and Ming periods. The excavation clarified relatively direct stratigraphic evidence on the typological evolution of the vessels typical of the Song and Yuan periods and threw light on a batch of egg-white-glazed “shu fu” porcelain objects of the early Yuan and some inscribed porcelain-making implements.
基金supported by the National Natural Science Foundation of China(NSFC)(No.51377001,No.61233008,No.61304092,)the International Science and Technology Cooperation Program of China(No.2015DFR70850)+1 种基金the State Grid Science and Technology Project of China(No.5216A014007V)the Science and Technology Project of Hunan Power Company of China(No.5216A213509X)
文摘A sequential design and global optimization method is proposed to coordinately design local and widearea controllers to enhance the overall stability of largescale power system.The sequential design is used to assign the distributed local power system stabilizer (LPSS) and high-voltage direct current (HVDC) wide-area stabilizing controller (HVDC-WASC) to the concerned damping modes.The global optimization is used to simultaneously optimize all the overall control gains of LPSSs and HVDCWASC.Moreover,the optimization model,which has an adaptive ability of searching and updating dominant oscillation modes,is established.Both the linear analysis and nonlinear simulation results verify the effectiveness of the proposed design method in enhancing the stability of large-scale power systems.
基金the National Natural Science Foundation of China(71403142,71774100,71690241)Young Elite Scientists Sponsorship Program of the Chinese Association for Science andTechnology(YESS20160140)BeijingNatural Science Foundation(9162008).
文摘Energy conservation and emissions reduction have become increasingly significant for automobiles due to the severity of the current energy situation.Hybrid electric vehicle(HEV)technology is one of the most promising solutions.This study investigated the total efficiency of a HEV powertrain.To improve the total efficiency,the engine should be regulated to work at its highest efficiency and drive the wheels directly as much as possible.To accomplish this,we developed an energy management strategy based on the direct drive area(DDA)of the engine’s efficiency map.Several typical HEV models were built to compare the fuel consumption using DDA and rule-based strategies.Furthermore,the function of the HEV transmission system with DDA was considered.The transmission in a HEV should regulate the engine to work at its highest efficiency as much as possible,which is rather different than the regulation in an internal combustion engine vehicle.The functional change may lead to transmission systems with fewer gears but optimal gear ratios.If this trend is realized,the manufacturing cost of HEVs could be largely reduced.
文摘A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach involving Resistivity and IP methods. This investigation was allowed to collect data on forty-five (45) profiling lines at three acquisition levels (AB = 100 m, MN = 10 m;AB = 200 m, MN = 20 m and AB = 500 m, MN = 50 m) and two electric panels L1 and L4, using the Schlumberger array. Processing, modeling and interpretation of data collected using the Winsev, Res2Dinv and Surfer software helped in highlighting a conductive and strongly mineralized discontinuity in granite formations, which lined up with the NE-SW Kadei tectonic line. It extends beyond 100 m depth over an average width of 600 m. The mineralization associated with this discontinuity is identified by a high concentration of disseminated metalliferous minerals in quartz or pegmatite veins. The mining reconnaissance works in the study area and those of several authors have characterized this anomaly to a lode gold quartz or large pegmatite. The results of this study correlate with geological and tectonic data for the region marked by NE-SW Kadei tectonic line. Therefore, they confirm the reliability of a geoelectrical DC investigation method combining Resistivity and IP to the identification of ore bodies.
基金funded by National Natural Science Foundation of China grant number 51403210.
文摘A facile synthesis procedure is proposed to prepare homogeneous Zr and Ti co-doped SBA-15(Zr-Ti-SBA-15)with high specific surface area of 876.0m2 g−1.Based on“masking mechanism”from tanning,lactic acid was used as masking agent to obtain the uniform distribution of Zr and Ti species in the SBA-15 framework.The obtained materials were characterized by powder X-ray diffraction(XRD),nitrogen adsorption-desorption isotherms,scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray photoelectron(XPS).The results reveal that in mesoporous materials,the presence of lactic acid gives rise to the uniform distribution of Zr and Ti species.The adsorption equilibrium and kinetic studies of Zr-Ti-SBA-15 materials show that the adsorption process conforms to the Langmuir isotherm and pseudo-second-order kinetic model,respectively.Regenerational experiments show that the Zr-Ti-SBA-15 displays a significant adsorption ability for methylene blue(MB)(up to 291.6 mg/g),along with good reusability,indicating promising potentials of commercialization.Methodologically,this work provides a wide range of possibilities for further development of SBA-15 based on bimetallic and sewage disposal.
文摘For radiative direct exchange areas in three dimensional system, the Uniform Deterministic Discrete Method (UDDM) was adopted. The spherical surface dividing method for sending area element and the regular icosahedron for sending volume element can meet with the direct exchange area computation of any kind of zone pairs. The numerical examples of direct exchange area in three dimensional system with nonhomogeneous attenuation coefficients indicated that the UDDM can give very high numerical accuracy.
文摘ELECTROCORTICOGRAPHY (ECoG), the intraoperative recording of cortical potentials, has played an important role in the surgical management of patients with medically intractable epilepsy. This technique is useful in epilepsy surgery to delineate margins of epileptogenic zones, guide resection,
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(Grant No.25211817)。
文摘The dual-layer electrode for fuel cells is typically prepared by binding discrete catalyst nanoparticles onto a diffusion layer.Such a random packing forms a dense catalyst layer and thus creates a barrier for mass/ion transport,particularly for direct liquid fuel cells.Three-dimensional porous electrodes,a thin nano-porous catalyst layer uniformly distributed on the matrix surface of a foam-like structure,are typically employed to improve the mass/ion transport.Such a three-dimensional porous structure brings two critical advantages:(i)reduced mass/ion transport resistance for the delivery of the reactants via shortening the transport distance and(ii)enlarged electrochemical surface area,via reducing the dead pores,isolated particles and severe aggregations,for interfacial reactions.Moreover,the three-dimensional design is capable of fabricating binder-free electrodes,thereby eliminating the use of ionomers/binders and simplifying the fabrication process.In this work,three types of three-dimensional porous electrode are fabricated,via different preparation methods,for direct formate fuel cells:(i)Pd/C nanoparticles coating on the nickel foam matrix surface(Pd-C/NF)via a dip-coating method,(ii)Pd nanoparticles depositing on the nickel foam matrix surface(Pd/NF)via reduction reaction deposition,and(iii)Pd nanoparticles embedding in the nickel foam matrix(Pd/(in)NF)via replacement reaction deposition.The latter two are binder-free three-dimensional porous electrodes.As a comparison,a conventional dual-layer design,Pd/C nanoparticles painting on the nickel foam layer(Pd-C//NF),is also prepared via direct painting method.It is shown that the use of the three-dimensional Pd-C/NF electrode as the anode in a direct formate fuel cell results in a peak power density of 45.0 mW cm^(-2)at 60℃,which is two times of that achieved by using a conventional dual-layer design(19.5 mW cm^(-2)).This performance improvement is mainly attributed to the unique three-dimensional structure design,which effectively enhances the mass/ion
