Nanoscale two-dimensional(2D)organic materials have attracted significant interest on account of their unique properties,which result from their ultrathin and flat morphology.Supramolecular 2D nanomaterials prepared b...Nanoscale two-dimensional(2D)organic materials have attracted significant interest on account of their unique properties,which result from their ultrathin and flat morphology.Supramolecular 2D nanomaterials prepared by bottom-up approaches have great potential in the creation of nanoscale devices with various applications,each controlled by the properties of its single-molecular components.Here,we report a uniform and controllable 2D rhombic micelles formed by block copolymers(BCPs)with poly(p-phenylenevinylene)(PPV)as core blocks.The supramolecular 2D nanostructures created in this way and driven byπ-πinteractions realize the precise separation of the semiconducting and insulating constituents of the constructed BCPs.With a vertical tunneling device design,the 2D rhombic micelles exhibited an on-off current ratio of>10^(4)and a high on-state current density of 6000 A cm^(−2)as the insulating layer was compressed by a conductive atomic force microscopy(C-AFM)probe.The tunneling device also shows a reproducible sensitivity on a flexible substrate,opening up potential flexible pressure sensor applications for such novel supramolecular 2D nanostructures.展开更多
Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive ...Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive control system （a cavity covered by a perforated plate） on a rotor blade should reduce the noise created by a moving shock. This article covers the numerical implementation of the Bohning/Doerffer transpiration law into the SPARC code and includes an extended validation against the experimental data for relatively simple geometries of transonic nozzles. It is a first step towards a full simulation of a helicopter rotor equipped with a noise reducing passive control device in hover and in forward flight conditions.展开更多
基金This studywas supported financially by the National Natural Science Foundation of China(nos.21975115,21733005,and 11674150)the Shenzhen Fundamental Research Programs(nos.JCYJ20180302180238419,JCYJ20190809161413310,and KQJSCX20180319114442157)+4 种基金the Shenzhen Nobel Prize Scientists Laboratory Project(no.C17213101)the Guangdong Provincial Key Laboratory of Catalysis(no.2020B121201002)the Key-Area Research and Development Program of Guangdong Province(no.2019B010931001)the Guangdong Innovative and Entrepreneurial Research Team Program(under contract nos.2016ZT06G587 and 2016ZT06D348)the“Shenzhen Sci-Tech Fund”(no.KYTDPT20181011104007).
文摘Nanoscale two-dimensional(2D)organic materials have attracted significant interest on account of their unique properties,which result from their ultrathin and flat morphology.Supramolecular 2D nanomaterials prepared by bottom-up approaches have great potential in the creation of nanoscale devices with various applications,each controlled by the properties of its single-molecular components.Here,we report a uniform and controllable 2D rhombic micelles formed by block copolymers(BCPs)with poly(p-phenylenevinylene)(PPV)as core blocks.The supramolecular 2D nanostructures created in this way and driven byπ-πinteractions realize the precise separation of the semiconducting and insulating constituents of the constructed BCPs.With a vertical tunneling device design,the 2D rhombic micelles exhibited an on-off current ratio of>10^(4)and a high on-state current density of 6000 A cm^(−2)as the insulating layer was compressed by a conductive atomic force microscopy(C-AFM)probe.The tunneling device also shows a reproducible sensitivity on a flexible substrate,opening up potential flexible pressure sensor applications for such novel supramolecular 2D nanostructures.
文摘Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive control system （a cavity covered by a perforated plate） on a rotor blade should reduce the noise created by a moving shock. This article covers the numerical implementation of the Bohning/Doerffer transpiration law into the SPARC code and includes an extended validation against the experimental data for relatively simple geometries of transonic nozzles. It is a first step towards a full simulation of a helicopter rotor equipped with a noise reducing passive control device in hover and in forward flight conditions.
