The RPS method,which integrates the real numerical solution, the perturbation solution and the shooting solution reasonably,can obtain the complex solution of a slab waveguide with small gain/loss regions without sear...The RPS method,which integrates the real numerical solution, the perturbation solution and the shooting solution reasonably,can obtain the complex solution of a slab waveguide with small gain/loss regions without searching the root in the entire complex plan.A revision to the RPS method is presented so that it can deal with the waveguide including large gain/loss regions.The application indicated that the simulation results are precise.展开更多
In the present work, an ideal Quadra-pole field has been realized by circular concave electrodes with a proper electrode angle The potential distribution in such an electrode system has been analyzed by assuming a sim...In the present work, an ideal Quadra-pole field has been realized by circular concave electrodes with a proper electrode angle The potential distribution in such an electrode system has been analyzed by assuming a simple boundary condition. The effect of the gap angle between the electrodes of the Quadra-pole lens on the optical properties has been studied such as the focal lengths, magnification and the chromatic aberration coefficient in the convergence and divergence planes.展开更多
As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers...As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers with tailorable morphologies and functions from a multi-injection microfluidic approach.The microfibers were generated by introducing PeQDs precursors into each barrel of the inner capillary array and mixing them in the spindle middle channel,where the poly(vinylidene fluoride)(PVDF)dissolved in N,N-dimethyl formamide(DMF)was also injected as their sheath fluid.During this process,the PeQDs were in situ synthesized with the connection of precursor cations and anions in the core fluid;while the PVDF formed solidified microfibers to encapsulate PeQDs with the fast dispersion of DMF into the outer aqueous solution.Thus,the good encapsulation of PeQDs was achieved in PVDF microfibers,which effectively protected them from different hostile environments.Because of the highly tunable spinning processes,the microfibers exhibited controllable diameters and helical geometric structures,and the encapsulated PeQDs could yield adjustable emission peaks.Based on the PeQDs microfibers,we have explored their potential as luminescent materials in barcodes and as flexible photodetectors,which make such microfibers highly versatile for different areas.展开更多
Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of o...Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of overdetermined partial differential equations: Given a system of quasi-linear PDEs of first order for one unknown function we find a necessary and sufficient condition for the existence of solutions in terms of the second jet of the coefficients. This generalizes to certain quasi-linear systems of first order for several unknown functions.展开更多
文摘The RPS method,which integrates the real numerical solution, the perturbation solution and the shooting solution reasonably,can obtain the complex solution of a slab waveguide with small gain/loss regions without searching the root in the entire complex plan.A revision to the RPS method is presented so that it can deal with the waveguide including large gain/loss regions.The application indicated that the simulation results are precise.
文摘In the present work, an ideal Quadra-pole field has been realized by circular concave electrodes with a proper electrode angle The potential distribution in such an electrode system has been analyzed by assuming a simple boundary condition. The effect of the gap angle between the electrodes of the Quadra-pole lens on the optical properties has been studied such as the focal lengths, magnification and the chromatic aberration coefficient in the convergence and divergence planes.
基金the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(52073060 and 61927805)+2 种基金the Natural Science Foundation of Jiangsu(BE2018707)Shenzhen Fundamental Research Program(JCYJ20190813152616459)China Postdoctoral Science Foundation(2020M680652)。
文摘As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers with tailorable morphologies and functions from a multi-injection microfluidic approach.The microfibers were generated by introducing PeQDs precursors into each barrel of the inner capillary array and mixing them in the spindle middle channel,where the poly(vinylidene fluoride)(PVDF)dissolved in N,N-dimethyl formamide(DMF)was also injected as their sheath fluid.During this process,the PeQDs were in situ synthesized with the connection of precursor cations and anions in the core fluid;while the PVDF formed solidified microfibers to encapsulate PeQDs with the fast dispersion of DMF into the outer aqueous solution.Thus,the good encapsulation of PeQDs was achieved in PVDF microfibers,which effectively protected them from different hostile environments.Because of the highly tunable spinning processes,the microfibers exhibited controllable diameters and helical geometric structures,and the encapsulated PeQDs could yield adjustable emission peaks.Based on the PeQDs microfibers,we have explored their potential as luminescent materials in barcodes and as flexible photodetectors,which make such microfibers highly versatile for different areas.
基金supported by National Research Foundation of Republic of Korea(Grant Nos.2011-0008976 and 2010-0011841)
文摘Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of overdetermined partial differential equations: Given a system of quasi-linear PDEs of first order for one unknown function we find a necessary and sufficient condition for the existence of solutions in terms of the second jet of the coefficients. This generalizes to certain quasi-linear systems of first order for several unknown functions.
