Using a special Painleve-Baecklund transformation as well as the extended mapping approach and the linear superposition theorem, we obtain new families of variable separation solutions to the （2＋1）-dimensional gene...Using a special Painleve-Baecklund transformation as well as the extended mapping approach and the linear superposition theorem, we obtain new families of variable separation solutions to the （2＋1）-dimensional generalized Broer-Kaup （GBK） system. Based on the derived exact solution, we reveal some novel evolutional behaviors of localized excitations, i.e. fission and fusion phenomena in the （2＋1）-dimensional GBK system.展开更多
The development of metal sulfide catalysts with remarkable activity toward efficient overall photocatalytic water splitting remains challenging owing to the dominant charge recombination and deficient catalytic active...The development of metal sulfide catalysts with remarkable activity toward efficient overall photocatalytic water splitting remains challenging owing to the dominant charge recombination and deficient catalytic active sites.Moreover,in the process of water oxidation catalysis,the inhibition of severe photocorrosion is an immense task,requiring effective photogenic hole-transfer kinetics.Herein,stratified Co-MnO_(2)@CdS/CoS hollow cubes with spatially separated catalytic sites were rationally designed and fabricated as highly efficient controllable catalysts for photocatalytic overall water splitting.The unique self-templated method,including a continuous anion/cation-exchange reaction,integrates a Co-doped oxidation co-catalyst(Co-MnO_(2))and a reduction co-catalyst(CoS)on the nanocubes with uniform interface contact and ultrathin two-dimensional(2D)nanometer sheets.We demonstrate that the stratified Co-MnO_(2)@CdS/CoS hollow cubes can provide an abundance of active sites for surface redox reactions and contribute to the separation and migration of the photoionization charge carriers.In particular,CoS nanoparticles dispersed on the walls of CdS hollow cubes were identified as reduction co-catalysts accelerating hydrogen generation,while Co-MnO_(2) nanosheets attached to the inner walls of the CdS hollow cube were oxidation co-catalysts,promoting oxygen evolution dynamics.Benefiting from the desirable structural and compositional advantages,optimized stratification of Co-MnO_(2)@CdS/CoS nanocubes provided a catalytic system devoid of precious metals,which exhibited a remarkable overall photocatalytic water-splitting rate(735.4(H_(2))and 361.1(O_(2))μmol h^(−1) g^(−1)),being among the highest values reported thus far for CdS-based catalysts.Moreover,an apparent quantum efficiency(AQE)of 1.32%was achieved for hydrogen evolution at 420 nm.This study emphasizes the importance of rational design on the structure and composition of photocatalysts for overall water splitting.展开更多
Scaffolded DNA origami, a versatile method to construct high yield self- assembled DNA nanostructures, has been investigated to develop water-soluble nanoarrays for label free RNA detection, drug delivery, molecular p...Scaffolded DNA origami, a versatile method to construct high yield self- assembled DNA nanostructures, has been investigated to develop water-soluble nanoarrays for label free RNA detection, drug delivery, molecular positioning and recognition, and spatially ordered catalysis of single molecule chemical reactions. Its attributes that facilitate these applications suggest DNA origami as a candidate platform for intracellular targeting. After the interaction with targeted proteins in cell lysate, it is critical to separate and concentrate DNA origami nanoarrays from the crude cell lysate for further analysis. The recent development of microchip isotachophoresis （ITP） provides an alternative robust sample preconcentration and electrophoretic separation method. In this study, we present online ITP for stacking, separation and identification of aptamer-functionalized DNA origami and its thrombin complex in a simple cross-channel fused silica microfluidic chip. In particular, the method achieved separation of a binding complex in less than 5 min and 150-fold signal enhancement. We successfully separated and analyzed the thrombin bound origami-aptamer spiked into cell lysate using on-chip ITP. Our results demonstrate that origami/thrombin nanostructures can be effectively separated from cell lysate using this method and that the structural integrity of the concentrated binding complex is maintained as confirmed by atomic force microscopy （AFM）. An ITP-based separation module can be easily coupled to other microchip pre- and post-processing steps to provide an integrated proteomics analysis platform for diagnostic applications.展开更多
A closed orientable Haken 3-manifold containing a non separating incompressible closed surface has two canonical Heegaard splittings, which are called self-amalgamation and bilateral self-amalgamation.Heegaard distanc...A closed orientable Haken 3-manifold containing a non separating incompressible closed surface has two canonical Heegaard splittings, which are called self-amalgamation and bilateral self-amalgamation.Heegaard distance introduced by Hempel is a useful index in studying Heegaard splitting. This paper studies the stabilization problem for the bilateral self-amalgamation, and proves that if the distance of bilateral selfamalgamation of a Heegaard splitting is at least 9, then it is unstabilized, weakly reducible and irreducible.展开更多
基金The project supported by the Natural Science Foundation of Zhejiang Province of China under Grant No. Y604106, the Foundation of ＂New Century 151 Talent Engineering＂ of Zhejiang Province, and the Key Academic Discipline Foundation of Zhejiang Province .The authors would like to thank Profs. J.F. Zhang, L.Q. Chen, and J.P. Fang for their fruitful discussions.
文摘Using a special Painleve-Baecklund transformation as well as the extended mapping approach and the linear superposition theorem, we obtain new families of variable separation solutions to the （2＋1）-dimensional generalized Broer-Kaup （GBK） system. Based on the derived exact solution, we reveal some novel evolutional behaviors of localized excitations, i.e. fission and fusion phenomena in the （2＋1）-dimensional GBK system.
文摘The development of metal sulfide catalysts with remarkable activity toward efficient overall photocatalytic water splitting remains challenging owing to the dominant charge recombination and deficient catalytic active sites.Moreover,in the process of water oxidation catalysis,the inhibition of severe photocorrosion is an immense task,requiring effective photogenic hole-transfer kinetics.Herein,stratified Co-MnO_(2)@CdS/CoS hollow cubes with spatially separated catalytic sites were rationally designed and fabricated as highly efficient controllable catalysts for photocatalytic overall water splitting.The unique self-templated method,including a continuous anion/cation-exchange reaction,integrates a Co-doped oxidation co-catalyst(Co-MnO_(2))and a reduction co-catalyst(CoS)on the nanocubes with uniform interface contact and ultrathin two-dimensional(2D)nanometer sheets.We demonstrate that the stratified Co-MnO_(2)@CdS/CoS hollow cubes can provide an abundance of active sites for surface redox reactions and contribute to the separation and migration of the photoionization charge carriers.In particular,CoS nanoparticles dispersed on the walls of CdS hollow cubes were identified as reduction co-catalysts accelerating hydrogen generation,while Co-MnO_(2) nanosheets attached to the inner walls of the CdS hollow cube were oxidation co-catalysts,promoting oxygen evolution dynamics.Benefiting from the desirable structural and compositional advantages,optimized stratification of Co-MnO_(2)@CdS/CoS nanocubes provided a catalytic system devoid of precious metals,which exhibited a remarkable overall photocatalytic water-splitting rate(735.4(H_(2))and 361.1(O_(2))μmol h^(−1) g^(−1)),being among the highest values reported thus far for CdS-based catalysts.Moreover,an apparent quantum efficiency(AQE)of 1.32%was achieved for hydrogen evolution at 420 nm.This study emphasizes the importance of rational design on the structure and composition of photocatalysts for overall water splitting.
文摘Scaffolded DNA origami, a versatile method to construct high yield self- assembled DNA nanostructures, has been investigated to develop water-soluble nanoarrays for label free RNA detection, drug delivery, molecular positioning and recognition, and spatially ordered catalysis of single molecule chemical reactions. Its attributes that facilitate these applications suggest DNA origami as a candidate platform for intracellular targeting. After the interaction with targeted proteins in cell lysate, it is critical to separate and concentrate DNA origami nanoarrays from the crude cell lysate for further analysis. The recent development of microchip isotachophoresis （ITP） provides an alternative robust sample preconcentration and electrophoretic separation method. In this study, we present online ITP for stacking, separation and identification of aptamer-functionalized DNA origami and its thrombin complex in a simple cross-channel fused silica microfluidic chip. In particular, the method achieved separation of a binding complex in less than 5 min and 150-fold signal enhancement. We successfully separated and analyzed the thrombin bound origami-aptamer spiked into cell lysate using on-chip ITP. Our results demonstrate that origami/thrombin nanostructures can be effectively separated from cell lysate using this method and that the structural integrity of the concentrated binding complex is maintained as confirmed by atomic force microscopy （AFM）. An ITP-based separation module can be easily coupled to other microchip pre- and post-processing steps to provide an integrated proteomics analysis platform for diagnostic applications.
基金supported by National Natural Science Foundation of China(Grant Nos.11271058 and 11371076)the Fundamental Research Funds for the Central Universities(Grant No.DUT14ZD208)
文摘A closed orientable Haken 3-manifold containing a non separating incompressible closed surface has two canonical Heegaard splittings, which are called self-amalgamation and bilateral self-amalgamation.Heegaard distance introduced by Hempel is a useful index in studying Heegaard splitting. This paper studies the stabilization problem for the bilateral self-amalgamation, and proves that if the distance of bilateral selfamalgamation of a Heegaard splitting is at least 9, then it is unstabilized, weakly reducible and irreducible.
