Droplets generation in Y-junctions and anti-Yjunctions microchannels are experimentally studied using a high speed digital microscopic system and numerical simulation.Geometric configuration of a microchannel,such as ...Droplets generation in Y-junctions and anti-Yjunctions microchannels are experimentally studied using a high speed digital microscopic system and numerical simulation.Geometric configuration of a microchannel,such as Y-angle（90°,135°,-90° and-135°）,channel depth and other factors have been taken into consideration.It is found that droplets generated in anti-Y-junctions have a smaller size and a shorter generation cycle compared with those in Yjunctions under the same experimental conditions.Through observing the internal velocity field,the vortex appearing in continuous phase in anti-Y-junctions is one of the key factors for the difference of droplet size and generation cycle.It is found that droplet size is bigger and generation cycle is longer when the absolute angle value of the intersection between the continuous and the dispersed phases（i.e.,the angle between the main channel and the continuous phase or the dispersed phase channel） increases.The droplet＇s size is influenced by the Y-angle,which varies with the channel depth in Y-junctions.The Y-angle has a positive effect on the droplet generation cycle,but a smaller height-width ratio will enhance the impact of a continuous and dispersed phase＇s intersection angle on the droplet generation cycle in Y-junctions microchannels.展开更多
In this communication,we report a synthetic approach to fabricate Y-junction Co nanowires and Y-junction Cu nanowires by AC electrodeposition using a hierarchically designed anodized aluminum oxide template.Morphology...In this communication,we report a synthetic approach to fabricate Y-junction Co nanowires and Y-junction Cu nanowires by AC electrodeposition using a hierarchically designed anodized aluminum oxide template.Morphology study showe that diameters of the stems and branches of the Y-junction nanowires were about 40 nm and 20 nm respectively.Structural analysis indicates that Co nanowires had a mixture of face-center-cubic and hexagonal-close-packed structures,whereas Cu nanowires had a face-center-cubic structure with a <110> texture.The Y-junction Co nanowires exhibited a longitudinal coercivity of 1300 Oe and remnant magnetization of 56%,which was affected by the growth direction and microstructure.The present method can be extended to other metallic systems and thus provides a simple and efficient way to fabricate Y-junction metal nanowires.展开更多
Optical couplers are the key components for signal distribution in optoelectronic transmitters and receivers. A new low-loss, large-angle Y-junction hybrid polymer optical coupler with an integrated microprism has bee...Optical couplers are the key components for signal distribution in optoelectronic transmitters and receivers. A new low-loss, large-angle Y-junction hybrid polymer optical coupler with an integrated microprism has been fabricated and demonstrated experimentally for use in a mixed-signal module environment. The results show that the radiation loss is small with relatively wide branching angle as compared to a conventional Y-junction coupler.展开更多
The flow field in junction is complicated due to the ripple property of oil flow velocity and different frequencies of two pumps in aircraft. In this study, the flow fields of T-junction and Y-junction were analyzed u...The flow field in junction is complicated due to the ripple property of oil flow velocity and different frequencies of two pumps in aircraft. In this study, the flow fields of T-junction and Y-junction were analyzed using shear stress transport （SST） model in ANSYS/CFX software. The simulation results identified the variation rule of velocity peak in T-junction with different frequencies and phase-differences, meanwhile, the eddy and velocity shock existed in the corner of the T-junction, and the limit working state was obtained. Although the eddy disappeared in Y-junction, the velocity shock and pressure loss were still too big. To address these faults, an arc-junction was designed. Based on the flow fields of arc-junction, the eddy in the junction corner disappeared and the maximum of velocity peak declined compared to T-and Y-junction. Additionally, 8 series of arc-junction with different radiuses were tested to get the variation rule of velocity peak. Through the computation of the pressure loss of three junctions, the arc-junction had a lowest loss value, and its pressure loss reached the minimum value when the curvature radius is 35.42 mm, meanwhile, the velocity shock has decreased in a low phase.展开更多
Y-junction photonic power splitters are essential in photonic integrated circuits.In this paper,a tunable Y-junction splitter is introduced using a standard silicon-on-insulator platform.It features a single-point con...Y-junction photonic power splitters are essential in photonic integrated circuits.In this paper,a tunable Y-junction splitter is introduced using a standard silicon-on-insulator platform.It features a single-point control mechanism of both the turnability of power splitting ratios and the non-volatility with optical phase change materials(O-PCMs).This nonvolatile Yjunction splitter has a broadband of 350 nm(from 1300 to 1650 nm)with an about 0.7 dB low insertion loss.Using the direct binary search(DBS)inverse design algorithm,a circular point was identified to fill the phase change material Sb_(2)S_(3)within the coupling area of the Y-junction photonic power splitter.Six example power splitting ratios of 1.86,1.70,1.50,1.34,1.21,and 1.14 were realized under single-point control using phase changes at 1550 nm with a 0.35 dB low insertion loss.Furthermore,we also implemented a five-stage cascaded array,with the final stage consisting of 16 Y-junction splitters.These results are useful for significantly simplifying the control of photonic circuits.展开更多
基金supported by the National Natural Science Foundation of China(Grants 11072011 and 11002007)
文摘Droplets generation in Y-junctions and anti-Yjunctions microchannels are experimentally studied using a high speed digital microscopic system and numerical simulation.Geometric configuration of a microchannel,such as Y-angle（90°,135°,-90° and-135°）,channel depth and other factors have been taken into consideration.It is found that droplets generated in anti-Y-junctions have a smaller size and a shorter generation cycle compared with those in Yjunctions under the same experimental conditions.Through observing the internal velocity field,the vortex appearing in continuous phase in anti-Y-junctions is one of the key factors for the difference of droplet size and generation cycle.It is found that droplet size is bigger and generation cycle is longer when the absolute angle value of the intersection between the continuous and the dispersed phases（i.e.,the angle between the main channel and the continuous phase or the dispersed phase channel） increases.The droplet＇s size is influenced by the Y-angle,which varies with the channel depth in Y-junctions.The Y-angle has a positive effect on the droplet generation cycle,but a smaller height-width ratio will enhance the impact of a continuous and dispersed phase＇s intersection angle on the droplet generation cycle in Y-junctions microchannels.
基金financially supported partially by a NSF award CMMI-0825990
文摘In this communication,we report a synthetic approach to fabricate Y-junction Co nanowires and Y-junction Cu nanowires by AC electrodeposition using a hierarchically designed anodized aluminum oxide template.Morphology study showe that diameters of the stems and branches of the Y-junction nanowires were about 40 nm and 20 nm respectively.Structural analysis indicates that Co nanowires had a mixture of face-center-cubic and hexagonal-close-packed structures,whereas Cu nanowires had a face-center-cubic structure with a <110> texture.The Y-junction Co nanowires exhibited a longitudinal coercivity of 1300 Oe and remnant magnetization of 56%,which was affected by the growth direction and microstructure.The present method can be extended to other metallic systems and thus provides a simple and efficient way to fabricate Y-junction metal nanowires.
文摘Optical couplers are the key components for signal distribution in optoelectronic transmitters and receivers. A new low-loss, large-angle Y-junction hybrid polymer optical coupler with an integrated microprism has been fabricated and demonstrated experimentally for use in a mixed-signal module environment. The results show that the radiation loss is small with relatively wide branching angle as compared to a conventional Y-junction coupler.
基金supported by the National Natural Science Foundation of China(No.51175014)
文摘The flow field in junction is complicated due to the ripple property of oil flow velocity and different frequencies of two pumps in aircraft. In this study, the flow fields of T-junction and Y-junction were analyzed using shear stress transport （SST） model in ANSYS/CFX software. The simulation results identified the variation rule of velocity peak in T-junction with different frequencies and phase-differences, meanwhile, the eddy and velocity shock existed in the corner of the T-junction, and the limit working state was obtained. Although the eddy disappeared in Y-junction, the velocity shock and pressure loss were still too big. To address these faults, an arc-junction was designed. Based on the flow fields of arc-junction, the eddy in the junction corner disappeared and the maximum of velocity peak declined compared to T-and Y-junction. Additionally, 8 series of arc-junction with different radiuses were tested to get the variation rule of velocity peak. Through the computation of the pressure loss of three junctions, the arc-junction had a lowest loss value, and its pressure loss reached the minimum value when the curvature radius is 35.42 mm, meanwhile, the velocity shock has decreased in a low phase.
基金supported by the National Key R&D Program of China(No.2022YFF0706005)the National Natural Science Foundation of China(Nos.61805278,12272407,62275269,62275271,and 62305387)+4 种基金the Chongqing Natural Science Foundation(No.CSTB2024NSCQ-LZX0033)the China Postdoctoral Science Foundation(No.2018M633704)the Foundation of NUDT(No.ZK23-03)the Natural Science FoundationofHunanProvince(Nos.2023JJ40683,2022JJ40552,and 2020JJ5646)the Hunan Provincial InnovationFoundationforPostgraduate,China(No.CX20230009)。
文摘Y-junction photonic power splitters are essential in photonic integrated circuits.In this paper,a tunable Y-junction splitter is introduced using a standard silicon-on-insulator platform.It features a single-point control mechanism of both the turnability of power splitting ratios and the non-volatility with optical phase change materials(O-PCMs).This nonvolatile Yjunction splitter has a broadband of 350 nm(from 1300 to 1650 nm)with an about 0.7 dB low insertion loss.Using the direct binary search(DBS)inverse design algorithm,a circular point was identified to fill the phase change material Sb_(2)S_(3)within the coupling area of the Y-junction photonic power splitter.Six example power splitting ratios of 1.86,1.70,1.50,1.34,1.21,and 1.14 were realized under single-point control using phase changes at 1550 nm with a 0.35 dB low insertion loss.Furthermore,we also implemented a five-stage cascaded array,with the final stage consisting of 16 Y-junction splitters.These results are useful for significantly simplifying the control of photonic circuits.
