O436.1 94063864离焦散斑照相术的错位干涉特性及其应用=Characteristicof shearing inteference in defocusedspeckle photography and its application[刊,中]/陆福一,张朝晖(西安工业大学应用物理系.陕西,西安(710072))//光子学报.-1...O436.1 94063864离焦散斑照相术的错位干涉特性及其应用=Characteristicof shearing inteference in defocusedspeckle photography and its application[刊,中]/陆福一,张朝晖(西安工业大学应用物理系.陕西,西安(710072))//光子学报.-1994,23(1).-54-58通过相关计算和滤波分析,得出了错位干涉特性。展开更多
Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow ch...Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow characteristics and performances of the generic hypersonic inlets by numerical simulation under the design conditions of a flight Mach number of 6 and an altitude of 26 km.The results show that the local shock interference patterns in the vicinity of the blunted cowl-lips have a substantial influence on the flow characteristics of the hypersonic inlets even though the blunting radius is very small,which contribute to a pronounced degradation of the inlet performance.The Equal Length blunting Manner(ELM)is the most optimal in that a nearly even reflection of the ramp shock produces an approximately straight and weak cowl reflection shock.The minimal total pressure loss,the lowest cowl drag,maximum mass-capture and the minimal aeroheating are achieved for the hypersonic inlet.For the other blunting manners,the ramp shock cannot reflect evenly and produces more curved cowl reflection shock.The Type V shock interference pattern occurs for the Cross Section Cutting blunting Manner(CSCM)and the strongest cowl reflection shock gives rise to the largest flow loss and drag.The cowl-lip blunted by the other two blunting manners is subjected to the shock interference pattern that transits with an increase in the blunting radius.Accordingly,the peak heat flux does not fall monotonously with the blunting radius increasing.Moreover,the cowl-lip surface suffers from severe aerothermal load when the shear layer or the supersonic jet impinges on the wall.展开更多
A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presen...A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring.展开更多
The origin of the anomalous transport feature appearing at a conductance G 0.7× （2e2/h） in quasi-lD ballistic devices-the so-called 0.7 anomaly-represents a long standing puzzle. Several mechanisms have been pr...The origin of the anomalous transport feature appearing at a conductance G 0.7× （2e2/h） in quasi-lD ballistic devices-the so-called 0.7 anomaly-represents a long standing puzzle. Several mechanisms have been proposed to explain it, but a general consensus has not been achieved. Proposed explanations have been based on quantum interference, the Kondo effect, Wigner crystallization, and other phenomena. A key open issue is whether the point defects that can occur in these low-dimensional devices are the physical cause behind this conductance anomaly. Here we adopt a scanning gate microscopy technique to map individual impurity positions in several quasi-lD constrictions and correlate these with conductance characteristics. Our data demonstrate that the 0.7 anomaly can be observed irrespective of the presence of localized defects, and we conclude that the 0.7 anomaly is a fundamental property of low-dimensional systems.展开更多
文摘O436.1 94063864离焦散斑照相术的错位干涉特性及其应用=Characteristicof shearing inteference in defocusedspeckle photography and its application[刊,中]/陆福一,张朝晖(西安工业大学应用物理系.陕西,西安(710072))//光子学报.-1994,23(1).-54-58通过相关计算和滤波分析,得出了错位干涉特性。
基金supported by the National Natural Science Foundation of China(Grant Nos.90716014 and 91216115)
文摘Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow characteristics and performances of the generic hypersonic inlets by numerical simulation under the design conditions of a flight Mach number of 6 and an altitude of 26 km.The results show that the local shock interference patterns in the vicinity of the blunted cowl-lips have a substantial influence on the flow characteristics of the hypersonic inlets even though the blunting radius is very small,which contribute to a pronounced degradation of the inlet performance.The Equal Length blunting Manner(ELM)is the most optimal in that a nearly even reflection of the ramp shock produces an approximately straight and weak cowl reflection shock.The minimal total pressure loss,the lowest cowl drag,maximum mass-capture and the minimal aeroheating are achieved for the hypersonic inlet.For the other blunting manners,the ramp shock cannot reflect evenly and produces more curved cowl reflection shock.The Type V shock interference pattern occurs for the Cross Section Cutting blunting Manner(CSCM)and the strongest cowl reflection shock gives rise to the largest flow loss and drag.The cowl-lip blunted by the other two blunting manners is subjected to the shock interference pattern that transits with an increase in the blunting radius.Accordingly,the peak heat flux does not fall monotonously with the blunting radius increasing.Moreover,the cowl-lip surface suffers from severe aerothermal load when the shear layer or the supersonic jet impinges on the wall.
文摘A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring.
基金This work was supported by the Italian Ministry of Research （Ministero dell＇Istruzione, dell＇Universitae della Ricerca （MIUR）-Fondo per gli Investimenti della Ricerca di Base （FIRB） project No. RBID08B3FM） and by the Italian Ministry of Foreign Affairs （Ministero degli Affari Esteri, Direzione Generale per la Promozione del Sistema Paese, progetto： Nanoelettronica quantistica per le tecnologie delle informazioni）. Two of us （C.R. and W.W.） thank the Swiss National Science Foundation （SNSF） financial support.
文摘The origin of the anomalous transport feature appearing at a conductance G 0.7× （2e2/h） in quasi-lD ballistic devices-the so-called 0.7 anomaly-represents a long standing puzzle. Several mechanisms have been proposed to explain it, but a general consensus has not been achieved. Proposed explanations have been based on quantum interference, the Kondo effect, Wigner crystallization, and other phenomena. A key open issue is whether the point defects that can occur in these low-dimensional devices are the physical cause behind this conductance anomaly. Here we adopt a scanning gate microscopy technique to map individual impurity positions in several quasi-lD constrictions and correlate these with conductance characteristics. Our data demonstrate that the 0.7 anomaly can be observed irrespective of the presence of localized defects, and we conclude that the 0.7 anomaly is a fundamental property of low-dimensional systems.
