The numerical solution of the stable basic flow on a 3-D boundary layer is obtained by using local ejection, local suction, and combination of local ejection and suction to simulate the local rough wall. The evolution...The numerical solution of the stable basic flow on a 3-D boundary layer is obtained by using local ejection, local suction, and combination of local ejection and suction to simulate the local rough wall. The evolution of 3-D disturbance T-S wave is studied in the spatial processes, and the effects of form and distribution structure of local roughness on the growth rate of the 3-D disturbance wave and the flow stability are discussed. Numerical results show that the growth of the disturbance wave and the form of vortices are accelerated by the 3-D local roughness. The modification of basic flow owing to the evolvement of the finite amplitude disturbance wave and the existence of spanwise velocity induced by the 3-D local roughness affects the stability of boundary layer. Propagation direction and phase of the disturbance wave shift obviously for the 3-D local roughness of the wall. The flow stability characteristics change if the form of the 2-D local roughness varies.展开更多
A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes p...A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.展开更多
The limited CO_(2)content in aqueous solution and low adsorption amount of CO_(2)on catalyst surface lead to poor photocatalytic CO_(2)reduction activity and selectivity.Herein,the design and fabrication of a novel ph...The limited CO_(2)content in aqueous solution and low adsorption amount of CO_(2)on catalyst surface lead to poor photocatalytic CO_(2)reduction activity and selectivity.Herein,the design and fabrication of a novel photocatalytic architecture is reported,accomplished via chemical vapor deposition of polymeric carbon nitride on carbon paper.The as-obtained samples with a hydrophobic surface exhibit excellent CO_(2)transport and adsorption ability,as well as the building of triphase air-liquid-solid(CO_(2)-H_(2)O-catalyst)joint interfaces,eventually resulting in the inhibition of H2 evolution and great promotion of CO_(2)reduction with a selectivity of 78.6%.The addition of phosphate to reaction environment makes further improvement of CO_(2)photoreduction into carbon fuels with a selectivity of 93.8%and an apparent quantum yield of 0.4%.This work provides new insight for constructing efficient photocatalytic architecture of CO_(2)photoreduction in aqueous solution and demonstrates that phosphate could play a key role in this process.展开更多
La（0.6）Sr（0.4）Co（0.2）Fe（0.8）O（3-δ）（LSCF） anodes were infiltrated by Gd（0.2）Ce（0.8）O（1.9）GDC） nanoparticles to improve the oxygen evolution reaction（OER） performance of solid oxide electrolysis ce...La（0.6）Sr（0.4）Co（0.2）Fe（0.8）O（3-δ）（LSCF） anodes were infiltrated by Gd（0.2）Ce（0.8）O（1.9）GDC） nanoparticles to improve the oxygen evolution reaction（OER） performance of solid oxide electrolysis cells（SOECs） in CO2 electroreduction. The effect of GDC loading was investigated, and 10 wt% GDC nanoparticle infiltration of the LSCF（10 GDC/LSCF） anode results in the highest OER performance. Electrochemical impedance spectra measurements indicate that the infiltration by GDC nanoparticles greatly decreases the polarization resistance of the SOECs with the 10 GDC/LSCF anodes. The following distribution of relaxation time analysis suggests that four individual electrode processes are involved in the OER and that all of them are accelerated on the 10 GDC/LSCF anode. Three phase boundaries, surface oxygen vacancies, and bulk oxygen mobility increased, based on scanning electron microscopy and temperature-programmed desorption of O2 characterizations, and contributed to the enhancement of the four electrode processes of the OER and electrochemical performance of SOECs.展开更多
Globalization, which is characterized by the escalating mobility of capital, people, ideas and information on a universal scale, has become a sweeping theme in the contemporary world. Tourism and its associated econom...Globalization, which is characterized by the escalating mobility of capital, people, ideas and information on a universal scale, has become a sweeping theme in the contemporary world. Tourism and its associated economic activities are evidently not immune to such a wider context of the world economy. In the past one or two decades, a stable increase has been witnessed in international tourist flows, inter-regional and inter-organizational alliances, and foreign direct investment. These trends are especially prevalent in the developing world, largely because of their pristine nature, di- verse culture, inexpensive goods and services, cheap labours, and other resources. However, it has been cautioned by some scholars, especially those from the Third World countries, that tourism is an industry run by and for the rich, more powerful nations and their corresponding multinational corporations. This article, from the perspective of political economy, supplemented with views from development studies, made a normative analysis on the impacts of the glob- alization of tourism on the Third World destination countries. Specifically, these impacts have been detailed in terms of economic, sociocultural, and ecological domains. It was demonstrated that without appropriate planning and manage- ment, the costs of Third World tourism development may accrue to the extent that its benefits are burned out. To avoid this happening, some suggestions have been made.展开更多
Accurate salt dome detection from 3D seismic data is crucial to different seismic data analysis applications. We present a new edge based approach for salt dome detection in migrated 3D seismic data. The proposed algo...Accurate salt dome detection from 3D seismic data is crucial to different seismic data analysis applications. We present a new edge based approach for salt dome detection in migrated 3D seismic data. The proposed algorithm overcomes the drawbacks of existing edge-based techniques which only consider edges in the x （crossline） and y （inline） directions in 2D data and the x （crossline）, y （inline）, and z （time） directions in 3D data. The algorithm works by combining 3D gradient maps computed along diagonal directions and those computed in x, y, and z directions to accurately detect the boundaries of salt regions. The combination of x, y, and z directions and diagonal edges ensures that the proposed algorithm works well even if the dips along the salt boundary are represented only by weak reflectors. Contrary to other edge and texture based salt dome detection techniques, the proposed algorithm is independent of the amplitude variations in seismic data. We tested the proposed algorithm on the publicly available Netherlands offshore F3 block. The results suggest that the proposed algorithm can detect salt bodies with high accuracy than existing gradient based and texture-based techniques when used separately. More importantly, the proposed approach is shown to be computationally efficient allowing for real time implementation and deployment.展开更多
The existence of solutions for second order three-point boundary value problems with nonlinear growth at resonance is studied by using Mawhin continuation theorem. The result shows that theorem 1 and 2 at least have o...The existence of solutions for second order three-point boundary value problems with nonlinear growth at resonance is studied by using Mawhin continuation theorem. The result shows that theorem 1 and 2 at least have one solution in c1[0,1]展开更多
It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages o...It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages obtained from the marine deposits of Northeast Russia,Sakhalin,Kuril,and Hokkaido Islands,dated by ammonites,foraminifers and other invertebrates. Based on detail correlation,the geological age of the terrestrial beds was defined. The guide fossils are recognized Marsypiletes cretacea,Tricolpites variexi- nus,Aquilapollenites conatus,A. stelkii,A. rombicus,Integricorpus bellum,Pseudointegricorpus clarireticula- tus,Triprojectus amoenus,Orbiculapollis lucidus,Wodehouseia aspera,Quercoidites minor,which had last oc- currence in the late Maastrichtian. The Danian palynofloras usually are dominated by Triatriopollenites plicoides and T. confusus. The species Anacolosidites subtrudens,Aquilapollenites proceros,A. spinulosus have last occurrence in the Danian. The K-T (K-Pg) boundary in the terrestrial deposits is defined in the base of the Upper Tsagayan Subformation and the base of the lower part of the Wuyun Formation. The latter is represented by aleuropelite to fine-grained sandstones. The change of taxonomical composition of palynospectra in similar environments could be determined by real change of flora at the Mesozoic and Cenozoic boundary,but not by changes of lithological facies or depositional environment,generally.展开更多
文摘The numerical solution of the stable basic flow on a 3-D boundary layer is obtained by using local ejection, local suction, and combination of local ejection and suction to simulate the local rough wall. The evolution of 3-D disturbance T-S wave is studied in the spatial processes, and the effects of form and distribution structure of local roughness on the growth rate of the 3-D disturbance wave and the flow stability are discussed. Numerical results show that the growth of the disturbance wave and the form of vortices are accelerated by the 3-D local roughness. The modification of basic flow owing to the evolvement of the finite amplitude disturbance wave and the existence of spanwise velocity induced by the 3-D local roughness affects the stability of boundary layer. Propagation direction and phase of the disturbance wave shift obviously for the 3-D local roughness of the wall. The flow stability characteristics change if the form of the 2-D local roughness varies.
基金Project(BA2006067)supported by Achievement Transitional Foundation of Jiangsu Province,China
文摘A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.
文摘The limited CO_(2)content in aqueous solution and low adsorption amount of CO_(2)on catalyst surface lead to poor photocatalytic CO_(2)reduction activity and selectivity.Herein,the design and fabrication of a novel photocatalytic architecture is reported,accomplished via chemical vapor deposition of polymeric carbon nitride on carbon paper.The as-obtained samples with a hydrophobic surface exhibit excellent CO_(2)transport and adsorption ability,as well as the building of triphase air-liquid-solid(CO_(2)-H_(2)O-catalyst)joint interfaces,eventually resulting in the inhibition of H2 evolution and great promotion of CO_(2)reduction with a selectivity of 78.6%.The addition of phosphate to reaction environment makes further improvement of CO_(2)photoreduction into carbon fuels with a selectivity of 93.8%and an apparent quantum yield of 0.4%.This work provides new insight for constructing efficient photocatalytic architecture of CO_(2)photoreduction in aqueous solution and demonstrates that phosphate could play a key role in this process.
基金This work was supported by the National Key R&D Program of China(2017YFA0700102)the National Natural Science Foundation of China(21703237,21573222,91545202)+1 种基金Dalian Institute of Chemical Physics(DICP DMTO201702)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020200)and CAS Youth Innovation Promotion(2015145)~~
文摘La（0.6）Sr（0.4）Co（0.2）Fe（0.8）O（3-δ）（LSCF） anodes were infiltrated by Gd（0.2）Ce（0.8）O（1.9）GDC） nanoparticles to improve the oxygen evolution reaction（OER） performance of solid oxide electrolysis cells（SOECs） in CO2 electroreduction. The effect of GDC loading was investigated, and 10 wt% GDC nanoparticle infiltration of the LSCF（10 GDC/LSCF） anode results in the highest OER performance. Electrochemical impedance spectra measurements indicate that the infiltration by GDC nanoparticles greatly decreases the polarization resistance of the SOECs with the 10 GDC/LSCF anodes. The following distribution of relaxation time analysis suggests that four individual electrode processes are involved in the OER and that all of them are accelerated on the 10 GDC/LSCF anode. Three phase boundaries, surface oxygen vacancies, and bulk oxygen mobility increased, based on scanning electron microscopy and temperature-programmed desorption of O2 characterizations, and contributed to the enhancement of the four electrode processes of the OER and electrochemical performance of SOECs.
文摘Globalization, which is characterized by the escalating mobility of capital, people, ideas and information on a universal scale, has become a sweeping theme in the contemporary world. Tourism and its associated economic activities are evidently not immune to such a wider context of the world economy. In the past one or two decades, a stable increase has been witnessed in international tourist flows, inter-regional and inter-organizational alliances, and foreign direct investment. These trends are especially prevalent in the developing world, largely because of their pristine nature, di- verse culture, inexpensive goods and services, cheap labours, and other resources. However, it has been cautioned by some scholars, especially those from the Third World countries, that tourism is an industry run by and for the rich, more powerful nations and their corresponding multinational corporations. This article, from the perspective of political economy, supplemented with views from development studies, made a normative analysis on the impacts of the glob- alization of tourism on the Third World destination countries. Specifically, these impacts have been detailed in terms of economic, sociocultural, and ecological domains. It was demonstrated that without appropriate planning and manage- ment, the costs of Third World tourism development may accrue to the extent that its benefits are burned out. To avoid this happening, some suggestions have been made.
基金supported by the Center for Energy and Geo Processing(CeGP) at King Fahd University of Petroleum&Minerals(KFUPM),under Project no.GTEC 1401-1402
文摘Accurate salt dome detection from 3D seismic data is crucial to different seismic data analysis applications. We present a new edge based approach for salt dome detection in migrated 3D seismic data. The proposed algorithm overcomes the drawbacks of existing edge-based techniques which only consider edges in the x （crossline） and y （inline） directions in 2D data and the x （crossline）, y （inline）, and z （time） directions in 3D data. The algorithm works by combining 3D gradient maps computed along diagonal directions and those computed in x, y, and z directions to accurately detect the boundaries of salt regions. The combination of x, y, and z directions and diagonal edges ensures that the proposed algorithm works well even if the dips along the salt boundary are represented only by weak reflectors. Contrary to other edge and texture based salt dome detection techniques, the proposed algorithm is independent of the amplitude variations in seismic data. We tested the proposed algorithm on the publicly available Netherlands offshore F3 block. The results suggest that the proposed algorithm can detect salt bodies with high accuracy than existing gradient based and texture-based techniques when used separately. More importantly, the proposed approach is shown to be computationally efficient allowing for real time implementation and deployment.
文摘The existence of solutions for second order three-point boundary value problems with nonlinear growth at resonance is studied by using Mawhin continuation theorem. The result shows that theorem 1 and 2 at least have one solution in c1[0,1]
基金financial supports given by the NSFC(China,Projects 30220130698,40842002)the Presidium FEBRAS(grant#09-I-P15-02)
文摘It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages obtained from the marine deposits of Northeast Russia,Sakhalin,Kuril,and Hokkaido Islands,dated by ammonites,foraminifers and other invertebrates. Based on detail correlation,the geological age of the terrestrial beds was defined. The guide fossils are recognized Marsypiletes cretacea,Tricolpites variexi- nus,Aquilapollenites conatus,A. stelkii,A. rombicus,Integricorpus bellum,Pseudointegricorpus clarireticula- tus,Triprojectus amoenus,Orbiculapollis lucidus,Wodehouseia aspera,Quercoidites minor,which had last oc- currence in the late Maastrichtian. The Danian palynofloras usually are dominated by Triatriopollenites plicoides and T. confusus. The species Anacolosidites subtrudens,Aquilapollenites proceros,A. spinulosus have last occurrence in the Danian. The K-T (K-Pg) boundary in the terrestrial deposits is defined in the base of the Upper Tsagayan Subformation and the base of the lower part of the Wuyun Formation. The latter is represented by aleuropelite to fine-grained sandstones. The change of taxonomical composition of palynospectra in similar environments could be determined by real change of flora at the Mesozoic and Cenozoic boundary,but not by changes of lithological facies or depositional environment,generally.
