The most important topics in the world todav are environmental and resource issues.Ihe development of green and clean enerev is still one of the ereat challenges of social sustainable development.Two-dimensiona(2D)met...The most important topics in the world todav are environmental and resource issues.Ihe development of green and clean enerev is still one of the ereat challenges of social sustainable development.Two-dimensiona(2D)metal-organic frameworks(MOFs)and derivatives have exceptional potential as high-efhiciency electrocatalvsts for clean enerey technologies.This review summarizes various synthesis strategies and applications of 2D MOFs and derivatives in electrocatalysis.Firstly,we will outline the advantages and uniqueness of 2D MOFs and derivatives.as well as their applicable areas.Secondly,the svnthetic strategies of 2D MOFs and derivatives are briefly classified Fach category is summarized and we list classic representative fabrication methods,including specific fabrication methods and mechanisms,corresponding structural characteristics.and insights into the advantages and limitations of the svnthesis method.Thirdly,we separately classify and summarize the application of 2D MOFs and derivatives in electrocatalysis,including electrocatalytic water splitting,oxygen reduction reaction(ORR),CO reduction reaction(CO.RR),and other electrocatalvtic applications.Finally.the development prospects and existing challenges to 2D MOEs and derivatives are discussed.展开更多
This paper focuses on two cases of two-dimensional wave equations with fractal boundaries. The first case is the equation with classical derivative. The formal solution is obtained. And a definition of the solution is...This paper focuses on two cases of two-dimensional wave equations with fractal boundaries. The first case is the equation with classical derivative. The formal solution is obtained. And a definition of the solution is given. Then we prove that under certain conditions, the solution is a kind of fractal function, which is continuous, differentiable nowhere in its domain. Next, for specific given initial position and 3 different initial velocities, the graphs of solutions are sketched. By computing the box dimensions of boundaries of cross-sections for solution surfaces, we evaluate the range of box dimension of the vibrating membrane. The second case is the equation with p-type derivative. The corresponding solution is shown and numerical example is given.展开更多
Several global conclusions about an Ebenman's model of a population with competing juveniles and adults are derived in this paper. The problems about the number of non-trivial fixed points, the number of synchrono...Several global conclusions about an Ebenman's model of a population with competing juveniles and adults are derived in this paper. The problems about the number of non-trivial fixed points, the number of synchronous 2-cycles, and the number of attracting synchronous cycles are resolved. In a special case, the twice iteration of the 2-dimensional map can be reduced to a 1-dimensional map, and the existence of one or more continua of non-synchronous 2-cycles is pointed out. Numerical calculations are used to draw orbit diagrams which show complicated dynamics of this non-invertible 2-dimensional map. Experimental and field observational evidence is also discussed.展开更多
In this study,a convenient method using multi-step infrared spectroscopy,including Fourier transform infrared spectroscopy（FT-IR）,second derivative infrared spectroscopy（SD-IR） and two-dimensional correlation infr...In this study,a convenient method using multi-step infrared spectroscopy,including Fourier transform infrared spectroscopy（FT-IR）,second derivative infrared spectroscopy（SD-IR） and two-dimensional correlation infrared spectroscopy（2DCOS-IR）,was employed to analyze and discriminate ten marine sponges from two classes collected from the Xisha Islands in the South China Sea.Each sponge had an exclusive macroscopic fingerprint.From the IR spectra,it was noted that the main ingredient of calcareous sponges was calcium carbonate,but that of demosponges was proteins.For sponges from the same genus or having highly similar chemical profile（IR spectral profile）,SD-IR and 2DCOS-IR were applied to successfully reveal the tiny differences.It was demonstrated that the multi-step infrared spectroscopy was a feasible and objective approach for marine sponge identification.展开更多
基金Supported by the Zheiiang Provincial Natural Science Foundation,China(No.LY20E020001)the National Natural Science Foundation of China(Nos.51602301,51672251)the Fundamental Research Funds of Zhejiang Sci-Tech University,China(No.20190007)。
文摘The most important topics in the world todav are environmental and resource issues.Ihe development of green and clean enerev is still one of the ereat challenges of social sustainable development.Two-dimensiona(2D)metal-organic frameworks(MOFs)and derivatives have exceptional potential as high-efhiciency electrocatalvsts for clean enerey technologies.This review summarizes various synthesis strategies and applications of 2D MOFs and derivatives in electrocatalysis.Firstly,we will outline the advantages and uniqueness of 2D MOFs and derivatives.as well as their applicable areas.Secondly,the svnthetic strategies of 2D MOFs and derivatives are briefly classified Fach category is summarized and we list classic representative fabrication methods,including specific fabrication methods and mechanisms,corresponding structural characteristics.and insights into the advantages and limitations of the svnthesis method.Thirdly,we separately classify and summarize the application of 2D MOFs and derivatives in electrocatalysis,including electrocatalytic water splitting,oxygen reduction reaction(ORR),CO reduction reaction(CO.RR),and other electrocatalvtic applications.Finally.the development prospects and existing challenges to 2D MOEs and derivatives are discussed.
基金Supported by National Natural Science Foundation of China(Grant No.10571084)
文摘This paper focuses on two cases of two-dimensional wave equations with fractal boundaries. The first case is the equation with classical derivative. The formal solution is obtained. And a definition of the solution is given. Then we prove that under certain conditions, the solution is a kind of fractal function, which is continuous, differentiable nowhere in its domain. Next, for specific given initial position and 3 different initial velocities, the graphs of solutions are sketched. By computing the box dimensions of boundaries of cross-sections for solution surfaces, we evaluate the range of box dimension of the vibrating membrane. The second case is the equation with p-type derivative. The corresponding solution is shown and numerical example is given.
文摘Several global conclusions about an Ebenman's model of a population with competing juveniles and adults are derived in this paper. The problems about the number of non-trivial fixed points, the number of synchronous 2-cycles, and the number of attracting synchronous cycles are resolved. In a special case, the twice iteration of the 2-dimensional map can be reduced to a 1-dimensional map, and the existence of one or more continua of non-synchronous 2-cycles is pointed out. Numerical calculations are used to draw orbit diagrams which show complicated dynamics of this non-invertible 2-dimensional map. Experimental and field observational evidence is also discussed.
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China(No.81225023)the National Natural Science Fund of China(Nos.41476121, 81302691,81172978)+2 种基金the Innovation Program of Shanghai Municipal Education Commission(No.14YZ037)partially supported by Shanghai Subject Chief Scientist(No.12XD1400200)the financial support of the National High Technology Research and Development Program of China(863 Projects,No.2013AA092902)
文摘In this study,a convenient method using multi-step infrared spectroscopy,including Fourier transform infrared spectroscopy（FT-IR）,second derivative infrared spectroscopy（SD-IR） and two-dimensional correlation infrared spectroscopy（2DCOS-IR）,was employed to analyze and discriminate ten marine sponges from two classes collected from the Xisha Islands in the South China Sea.Each sponge had an exclusive macroscopic fingerprint.From the IR spectra,it was noted that the main ingredient of calcareous sponges was calcium carbonate,but that of demosponges was proteins.For sponges from the same genus or having highly similar chemical profile（IR spectral profile）,SD-IR and 2DCOS-IR were applied to successfully reveal the tiny differences.It was demonstrated that the multi-step infrared spectroscopy was a feasible and objective approach for marine sponge identification.
