Alginate is a natural polysaccharide polymer.Hydrogel filtration membranes prepared from alginate show excellent fouling resistance and controllable separation performance,but poor mechanical properties limit the use ...Alginate is a natural polysaccharide polymer.Hydrogel filtration membranes prepared from alginate show excellent fouling resistance and controllable separation performance,but poor mechanical properties limit the use of algae hydrogels.In this study,Ba^(2+)/Ca^(2+)co-crosslinked alginate(Ba/CaAlg)hydrogel membrane was prepared by cross-linking sodium alginate with a blend aqueous solution of barium ions and calcium ions,and the membrane was applied to the separation of dyes/salts from dyeing wastewater.Compared with the CaAlg membrane,the Ba/CaAlg hydrogel membrane exhibited more stable structure,and the mechanical properties and salt tolerance of the membrane were significantly improved.The flux of Ba/CaAlg membrane for methyl blue/sodium chloride mixed solution reached 43.5 L m^(−2) h^(−1),which was significantly higher than that of CaAlg membrane.Besides,the Ba/CaAlg membrane showed higher dye rejection(>99.6%)and lower salt rejection(<8.2%).The structure of Ba/CaAlg membrane was preliminarily simulated by molecular dynamics,and the pore size and distribution of the membrane were calculated.The Ba/CaAlg membrane has a broad application prospect in dyes/salts separation.展开更多
Realization of the efficient steering for photons streams from nano sources is essential for further progress in integrated photonic circuits,especially when involving nonlinear sources.In general,steering for nonline...Realization of the efficient steering for photons streams from nano sources is essential for further progress in integrated photonic circuits,especially when involving nonlinear sources.In general,steering for nonlinear sources needs additional optical control elements,limiting their application occasions as photonic devices.Here,we propose a simple and efficient beam steering scheme for the second-harmonic(SH)emission in the hybrid waveguide(consisting of CdSe nanobelts on the Au film)by mode-selective excitation.Adjusting the position of the incident beam illuminating on the tapered waveguide,the excitation types of guided modes can be selected,realizing the directionality control of SH emission.Stable steering of 6.1°for the SH emission is observed when the interference modes change from TE_(00)&TE_(01)to TE_(00)&TE_(02),which is confirmed by SH Fourier imaging and simulations.Our approach gets rid of the complex structural design and provides a new idea for beam steering of nonlinear optical devices with various nonlinear wavefronts.展开更多
基金supported by the National Natural Science Foundation of China(No.22078244)Scientific research and development project of SINOPEC(No.222443)the Science and Technology Plans of Tianjin(No.20JCYBJC00120).
文摘Alginate is a natural polysaccharide polymer.Hydrogel filtration membranes prepared from alginate show excellent fouling resistance and controllable separation performance,but poor mechanical properties limit the use of algae hydrogels.In this study,Ba^(2+)/Ca^(2+)co-crosslinked alginate(Ba/CaAlg)hydrogel membrane was prepared by cross-linking sodium alginate with a blend aqueous solution of barium ions and calcium ions,and the membrane was applied to the separation of dyes/salts from dyeing wastewater.Compared with the CaAlg membrane,the Ba/CaAlg hydrogel membrane exhibited more stable structure,and the mechanical properties and salt tolerance of the membrane were significantly improved.The flux of Ba/CaAlg membrane for methyl blue/sodium chloride mixed solution reached 43.5 L m^(−2) h^(−1),which was significantly higher than that of CaAlg membrane.Besides,the Ba/CaAlg membrane showed higher dye rejection(>99.6%)and lower salt rejection(<8.2%).The structure of Ba/CaAlg membrane was preliminarily simulated by molecular dynamics,and the pore size and distribution of the membrane were calculated.The Ba/CaAlg membrane has a broad application prospect in dyes/salts separation.
基金National Natural Science Foundation of China(12004222,12004223,12104317,91850207)China Postdoctoral Science Foundation(2020M682223,2020M682224)Science and Technology Innovation Commission of Shenzhen(20200810143204002)。
文摘Realization of the efficient steering for photons streams from nano sources is essential for further progress in integrated photonic circuits,especially when involving nonlinear sources.In general,steering for nonlinear sources needs additional optical control elements,limiting their application occasions as photonic devices.Here,we propose a simple and efficient beam steering scheme for the second-harmonic(SH)emission in the hybrid waveguide(consisting of CdSe nanobelts on the Au film)by mode-selective excitation.Adjusting the position of the incident beam illuminating on the tapered waveguide,the excitation types of guided modes can be selected,realizing the directionality control of SH emission.Stable steering of 6.1°for the SH emission is observed when the interference modes change from TE_(00)&TE_(01)to TE_(00)&TE_(02),which is confirmed by SH Fourier imaging and simulations.Our approach gets rid of the complex structural design and provides a new idea for beam steering of nonlinear optical devices with various nonlinear wavefronts.
