In recent years, the Cavally River has been subject to multiple activities, <span style="font-family:;" "="">including the construction of diversion channels and a bridge that makes it v...In recent years, the Cavally River has been subject to multiple activities, <span style="font-family:;" "="">including the construction of diversion channels and a bridge that makes it vulnerable to flooding. In order to assess the impact of these hydraulic structures on the <span>river hydrodynamic functioning, a 1D-2D model was realized. The</span> implementation of the 1D-2D model consisted </span><span style="font-family:;" "="">of </span><span style="font-family:;" "="">first </span><span style="font-family:;" "="">running</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">the 1D model, then the 2D model, and finally in coupling them. The 1D-2D model was designed with <span>the 1988 flood hydrograph, a Manning’s coefficient of 0.052 m<sup>1/3</sup>/s for the </span>minor bed and 0.06 m<sup>1/3</sup>/s for the major bed. The results of the hydraulic model show that the velocities are almost identical to those of the Cavally in natural operation. The values of the velocities are included between 0.4 m/s and 1.3 m/s at the level of the minor bed of the river and between 0.06 m/s and 0.71 m/s at the level of the floodplains. The average water level for flood propagation is 262.37 ± 0.44 m before construction of the structures and 262.23 ± <span>0.85 m after construction of the structures. The 0.41 m reduction in water</span> level due to the diversion canal and bridge is negligible compared to the total fluctuations of the Cavally River, which vary from 6 to 7 m over the year.</span>展开更多
TiO_(2)is a promising photocatalyst with limited use in practical applications owing to its wide bandgap,narrow light response range,and rapid recombination of photoexcited carriers.To address these limitations,a nove...TiO_(2)is a promising photocatalyst with limited use in practical applications owing to its wide bandgap,narrow light response range,and rapid recombination of photoexcited carriers.To address these limitations,a novel 1D/2D TiO_(2)/ZnIn_(2)S_(4)heterostructure was designed according to the principles of the S-scheme heterojunction.The TiO_(2)/ZnIn_(2)S_(4)(TZISx)hybrids prepared via a hydrothermal method afforded significant improvement in photocatalytic hydrogen evolution(PHE)in comparison to pristine TiO_(2)and ZnIn_(2)S_(4).In particular,the optimal TZIS2 sample(mass ratio of ZnIn_(2)S_(4)to TiO_(2)was 0.4)exhibited the highest PHE activity(6.03 mmol/h/g),which was approximately 3.7 and 2.0 times higher than those of pristine TiO_(2)and ZnIn_(2)S_(4),respectively.This improvement in the PHE of the TZIS2 sample could be attributed to the formation of an intimate heterojunction interface,high-efficiency separation of charge carriers,abundant reactive sites,and enhanced light absorption capacity.Notably,theoretical and experimental results demonstrated that the S-scheme mechanism of interfacial electron transfer in the TZISx composites facilitated the transfer and separation of photoexcited charge carriers,resulting in more isolated photoexcited electrons for the PHE reaction.展开更多
In this study, 1D and 2D shallow-water models were coupled to simulate unsteady flow in channel networks and embayment. The 1D model solved the 1D shallow-water equations (St. Venant) using the Preissmann box method a...In this study, 1D and 2D shallow-water models were coupled to simulate unsteady flow in channel networks and embayment. The 1D model solved the 1D shallow-water equations (St. Venant) using the Preissmann box method and targeted long narrow reaches of the river networks, while the 2D model targeted broad channels and embayment and solved the 2D shallow-water equations using a semi-implicit scheme applied to an unstructured grid of triangular cells. The 1D and 2D models were solved simultaneously by building a matrix for the free surface elevation at every 1D junction and 2D cell center. Velocities were then computed explicitly based on the results at the previous time step and the updated water level. The originality of the scheme arose from a novel coupling method. The results showed that the coupled 1D/2D model produced identical results as the full 2D model in classical to benchmark problems with considerable savings in computational effort. Application of the model to the Pearl River Estuary in southern China showed that complex patterns of tidal wave propagation could be efficiently modeled.展开更多
A Zn（Ⅱ） supramolecular coordination polymer, {[Zn2（L）2（m-bix）（H20）]6H2O}n（1）, with an interesting 1D→2D polythreading array from a flexible and angular organic aromaticpolycarboxylate ligand 5-（4-hydroxyp...A Zn（Ⅱ） supramolecular coordination polymer, {[Zn2（L）2（m-bix）（H20）]6H2O}n（1）, with an interesting 1D→2D polythreading array from a flexible and angular organic aromaticpolycarboxylate ligand 5-（4-hydroxypyridinium-l-ylmethyl）isophthalic acid （H2L）, and N-donorligand 1,3-bis（imidazol-l-ylmethyl）benzene （m-bix）, has been obtained under hydrothermalconditions and characterized by elemental analysis, powder X-ray diffraction （PXRD）, IR, thermalgravimetric analyses （TGA） and single-crystal X-ray diffraction. In 1, the Zn（Ⅱ） center has twocoordination geometries. One exhibits a trigonal bipyramidal coordination sphere, and the other isa tetrahedral geometry; L2- has two different coordination modes, with one connecting three Zn（Ⅱ）ions through two monodentate carboxylate groups and the monodentate hydroxyl group, and theother bridging two Zn（Ⅱ） ions through two carboxylate groups. The L2- anions connect the Zn（Ⅱ）centers forming an infinite 1D tubular structure. These 1D tubes are interconnected by the m-bixspacers to form a 2D framework. Such 2D layers are further assembled into a 3D supramolecularnetwork via hydrogen bonds. Meanwhile, the luminescent property of 1 has also been investigatedin detail.展开更多
The physical objective of solving for eigen-modes of a 1D quasiperiodic structure in photonics has been achieved. This was achieved thru considering this structure as a 1D projection or cut of a 2D periodic structure....The physical objective of solving for eigen-modes of a 1D quasiperiodic structure in photonics has been achieved. This was achieved thru considering this structure as a 1D projection or cut of a 2D periodic structure. And the problem is solved in a manner similar to 2D periodic photonic structures. A mechanical analogy (quasiperiodic orbits) helps to bring conceptual clarity.展开更多
文摘In recent years, the Cavally River has been subject to multiple activities, <span style="font-family:;" "="">including the construction of diversion channels and a bridge that makes it vulnerable to flooding. In order to assess the impact of these hydraulic structures on the <span>river hydrodynamic functioning, a 1D-2D model was realized. The</span> implementation of the 1D-2D model consisted </span><span style="font-family:;" "="">of </span><span style="font-family:;" "="">first </span><span style="font-family:;" "="">running</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">the 1D model, then the 2D model, and finally in coupling them. The 1D-2D model was designed with <span>the 1988 flood hydrograph, a Manning’s coefficient of 0.052 m<sup>1/3</sup>/s for the </span>minor bed and 0.06 m<sup>1/3</sup>/s for the major bed. The results of the hydraulic model show that the velocities are almost identical to those of the Cavally in natural operation. The values of the velocities are included between 0.4 m/s and 1.3 m/s at the level of the minor bed of the river and between 0.06 m/s and 0.71 m/s at the level of the floodplains. The average water level for flood propagation is 262.37 ± 0.44 m before construction of the structures and 262.23 ± <span>0.85 m after construction of the structures. The 0.41 m reduction in water</span> level due to the diversion canal and bridge is negligible compared to the total fluctuations of the Cavally River, which vary from 6 to 7 m over the year.</span>
文摘TiO_(2)is a promising photocatalyst with limited use in practical applications owing to its wide bandgap,narrow light response range,and rapid recombination of photoexcited carriers.To address these limitations,a novel 1D/2D TiO_(2)/ZnIn_(2)S_(4)heterostructure was designed according to the principles of the S-scheme heterojunction.The TiO_(2)/ZnIn_(2)S_(4)(TZISx)hybrids prepared via a hydrothermal method afforded significant improvement in photocatalytic hydrogen evolution(PHE)in comparison to pristine TiO_(2)and ZnIn_(2)S_(4).In particular,the optimal TZIS2 sample(mass ratio of ZnIn_(2)S_(4)to TiO_(2)was 0.4)exhibited the highest PHE activity(6.03 mmol/h/g),which was approximately 3.7 and 2.0 times higher than those of pristine TiO_(2)and ZnIn_(2)S_(4),respectively.This improvement in the PHE of the TZIS2 sample could be attributed to the formation of an intimate heterojunction interface,high-efficiency separation of charge carriers,abundant reactive sites,and enhanced light absorption capacity.Notably,theoretical and experimental results demonstrated that the S-scheme mechanism of interfacial electron transfer in the TZISx composites facilitated the transfer and separation of photoexcited charge carriers,resulting in more isolated photoexcited electrons for the PHE reaction.
基金financially supporrted by the National Key Research and Development Program of China(Grant No.2017YFC1404200)the National Natural Science Foundation of China(Grant Nos.51779150 and 51979040)
文摘In this study, 1D and 2D shallow-water models were coupled to simulate unsteady flow in channel networks and embayment. The 1D model solved the 1D shallow-water equations (St. Venant) using the Preissmann box method and targeted long narrow reaches of the river networks, while the 2D model targeted broad channels and embayment and solved the 2D shallow-water equations using a semi-implicit scheme applied to an unstructured grid of triangular cells. The 1D and 2D models were solved simultaneously by building a matrix for the free surface elevation at every 1D junction and 2D cell center. Velocities were then computed explicitly based on the results at the previous time step and the updated water level. The originality of the scheme arose from a novel coupling method. The results showed that the coupled 1D/2D model produced identical results as the full 2D model in classical to benchmark problems with considerable savings in computational effort. Application of the model to the Pearl River Estuary in southern China showed that complex patterns of tidal wave propagation could be efficiently modeled.
基金supported by Education Chamber of Henan Province(No.15A150068)
文摘A Zn（Ⅱ） supramolecular coordination polymer, {[Zn2（L）2（m-bix）（H20）]6H2O}n（1）, with an interesting 1D→2D polythreading array from a flexible and angular organic aromaticpolycarboxylate ligand 5-（4-hydroxypyridinium-l-ylmethyl）isophthalic acid （H2L）, and N-donorligand 1,3-bis（imidazol-l-ylmethyl）benzene （m-bix）, has been obtained under hydrothermalconditions and characterized by elemental analysis, powder X-ray diffraction （PXRD）, IR, thermalgravimetric analyses （TGA） and single-crystal X-ray diffraction. In 1, the Zn（Ⅱ） center has twocoordination geometries. One exhibits a trigonal bipyramidal coordination sphere, and the other isa tetrahedral geometry; L2- has two different coordination modes, with one connecting three Zn（Ⅱ）ions through two monodentate carboxylate groups and the monodentate hydroxyl group, and theother bridging two Zn（Ⅱ） ions through two carboxylate groups. The L2- anions connect the Zn（Ⅱ）centers forming an infinite 1D tubular structure. These 1D tubes are interconnected by the m-bixspacers to form a 2D framework. Such 2D layers are further assembled into a 3D supramolecularnetwork via hydrogen bonds. Meanwhile, the luminescent property of 1 has also been investigatedin detail.
文摘The physical objective of solving for eigen-modes of a 1D quasiperiodic structure in photonics has been achieved. This was achieved thru considering this structure as a 1D projection or cut of a 2D periodic structure. And the problem is solved in a manner similar to 2D periodic photonic structures. A mechanical analogy (quasiperiodic orbits) helps to bring conceptual clarity.
