Soft polymer optical fiber(SPOF)has shown great potential in optical-based wearable and implantable biosensors due to its excellent mechanical properties and optical guiding characteristics.However,the multimodality c...Soft polymer optical fiber(SPOF)has shown great potential in optical-based wearable and implantable biosensors due to its excellent mechanical properties and optical guiding characteristics.However,the multimodality characteristics of SPOF limit their integration with traditional fiber optic sensors.This article introduces for the first time a flexible fiber optic vibration sensor based on laser interference technology,which can be applied to vibration measurement under high stretch conditions.This sensor utilizes elastic optical fibers made of polydimethylsiloxane(PDMS)as sensing elements,combined with phase generating carrier technology,to achieve vibration measurement at 50−260 Hz within the stretch range of 0−42%.展开更多
A recyclable mercury(Ⅱ)optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction.The obtained multifunctional microspheres display...A recyclable mercury(Ⅱ)optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction.The obtained multifunctional microspheres displayed excellent fluorescence sensitivity and selectivity towards Hg^(2+)over other competing metal ions.A good linearity Stern-Volmer working plot(R2=0.9983)between the fluorescence intensity of multifunctional microspheres and the concentration of Hg^(2+)was constructed with a satisfactory detection limit of 2.3×10^(-8)mol·L^(-1).Their fluorescence response in the presence of Hg^(2+)is found to be almost reversible when treated by EDTA solution.Moreover,these pyrene-functionalized magnetic silica nanospheres can efficiently remove Hg^(2+)in aqueous solution and easily separated by appling an external magnetic field.These results indicate that functionalized core-shell magnetic silica microspheres are potentially promising materials for simultaneously detecting and removing environmental pollutants.展开更多
A novel technique of immobilizing indicator dyes by electrostatic adsorption and covalent bonding to fabricate optical sensors was developed.3-Amino-9-ethylcarbazole(AEC)was attached to the outmost surface of quartz g...A novel technique of immobilizing indicator dyes by electrostatic adsorption and covalent bonding to fabricate optical sensors was developed.3-Amino-9-ethylcarbazole(AEC)was attached to the outmost surface of quartz glass slide via aminosilanizing the slide,crosslinking chitosan,adsorbing Au nanoparticle,self-assembling HS(CH2)11OH,and coupling AEC.Thus, an AEC-immobilized optical sensor was obtained.The sensor exhibits a wide linear response range from 7.0×10- 7to 1.0×10 -4 mol/L and a correlation coefficient of 0.995 9 for the detection of 2-nitrophenol.The detection limit and response time of the sensor are 1.0×10- 7mol/L and less than 10 s,respectively.The fluorescence intensity of the used sensor can be restored to the blank value by simply rinsing with blank buffer.A very effective matrix for immobilizing indicator dye is provided by the proposed technique, which is adaptable to other indicator dyes with amino groups besides AEC.展开更多
In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space divis...In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space division multiple access, and a sensor node uses a modulating retro-reflector for communication. Thus while a random sampling matrix is used to guide the establishment of links between head cluster and sensor nodes, the random linear projection is accomplished. To establish multiple links at the same time, an optical space division multiple access antenna is designed. It works in fixed beams switching mode and consists of optic lens with a large field of view（FOV）, fiber array on the focal plane which is used to realize virtual channels segmentation, direction of arrival sensor, optical matrix switch and controller. Based on the angles of nodes＇ laser beams, by dynamically changing the route, optical matrix switch actualizes the multi-beam full duplex tracking receiving and transmission. Due to the structure of fiber array, there will be several fade zones both in the focal plane and in lens＇ FOV. In order to lower the impact of fade zones and harmonize multibeam, a fiber array adjustment is designed. By theoretical, simulated and experimental study, the antenna＇s qualitative feasibility is validated.展开更多
In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures...In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures with flexible base(S1),combined base(S2),and semi-rigid base(S3)were selected to perform field strain tests under static and dynamic load using the fiber Bragg grating optical sensing technology.The changing characteristics of the strain field along the horizontal and depth directions of pavements were analyzed.The results indicate that the most unfavorable asphalt pavement layers were the upper-middle surface layer and the lower base layer.In addition,the most unfavorable loading positions on the surface layer and the base layer were the center of wheel load and the gap center between two wheels,respectively.The most unfavorable layer of the surface layers gradually moved from the lower layer to the upper layer with the increase of base layer modulus.The power function relationships between structural layer strain and vehicle speed were revealed.The semi-rigid base asphalt pavement was the most durable pavement type,since its strain value was lower compared to those of the other structures.展开更多
Magneto optic(MO) fiber current sensors utility the Faraday effect of magneto op tic materials to sensing the magnetic(current)fields.The optical fiber sensors(O FS)offer great advantages of simple structure,high reli...Magneto optic(MO) fiber current sensors utility the Faraday effect of magneto op tic materials to sensing the magnetic(current)fields.The optical fiber sensors(O FS)offer great advantages of simple structure,high reliability,high accuracy and sensibility,immunity to electromagnetic interference.They are the most promised method to substitute the conventional current transducers(CTs),much attentions were focused on both domestic and abroad.Magneto optic properties of Faraday se n sing element have much affect on the performance of the optical fiber current se nsor.For used in the sensor system,MO materials with magneto optic characterist i cs of large Faraday rotation(FR)angle θ f ,low temperature sensibility,and suitable saturation field were general demanded. Development of MO materials is one of the most important problems of optical fiber current sensor research. In this paper,one mixed doped Bi substituted yttrium iron garnet crystal BiYb:Y I G, which has large and temperature stable FR angle,was grown from high temperatu re flux.By taking PbO+PbF 2 as the main flux,under the compositions of molar ra tio Y 2O 3:Yb 2O 3:Bi 2O 3:Fe 2O 3:(PbO+PbF 2+B 2O 3+CaCO 3)=7.64:1. 04:1.74:20.78:78:68.8,crystals of quite good quality were grown from melt flux,t he largest one has the size of 22mm×15mm×12mm.Magneto optic proprieties of Fa raday rotation angle and optical absorption spectrum of the BiYb:YIG crystal,expecial ly Y 2.289 Yb 0.246 Bi 0.465 Fe 5O 12 ,in the range of 0.7 1.9 μm waveband were measured.At λ =1.55μm,the BiYb:YIG crystal has special Fa raday rotation angle of -404deg/cm,temperature coefficient 4.2×10 -6 K -1 ,optical absorption coefficient 3.6cm -1 ,and figure of merit 25.8deg/dB . The results indicate that substituted with Bi 3+ can largely improve the Fa raday rotation of rear earth iron garnets.Because Faraday rotation angles of Yb 3Fe 5O 12 and Y 3Fe 5O 12 have opposite temperature dependency,ut ility the compensation effect of mix doped,co doped with some other ions,such a s Yb 3+ ,would decrease the temperature dependency of Bi substituted garnet. So the garnet crystal BiYb:YIG has high and temperature stable Faraday rotation an gle,very suitable to be used as Faraday effect materials for high sensibility an d temperature stable Optical fiber current sensors.Using BiYb:YIG as Faraday rot ation cell,a hybrid bulk crystal optical fiber current sensor was proposed and t ests under direct current(DC) and 50Hz alternating current(AC).The performance c haracteristics of the sensors system were:DC measurement,sensibility 0.01A, l inea rity 1.1%;AC measurement,sensibility 9.5A/mV ,accuracy ±1%,linearity 1.1%,dynam ic range 40dB.In conclusion,Faraday effect magneto optic optical fiber current sensors have higher sensibility and accuracy than conventional CTs.展开更多
文摘Soft polymer optical fiber(SPOF)has shown great potential in optical-based wearable and implantable biosensors due to its excellent mechanical properties and optical guiding characteristics.However,the multimodality characteristics of SPOF limit their integration with traditional fiber optic sensors.This article introduces for the first time a flexible fiber optic vibration sensor based on laser interference technology,which can be applied to vibration measurement under high stretch conditions.This sensor utilizes elastic optical fibers made of polydimethylsiloxane(PDMS)as sensing elements,combined with phase generating carrier technology,to achieve vibration measurement at 50−260 Hz within the stretch range of 0−42%.
文摘A recyclable mercury(Ⅱ)optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction.The obtained multifunctional microspheres displayed excellent fluorescence sensitivity and selectivity towards Hg^(2+)over other competing metal ions.A good linearity Stern-Volmer working plot(R2=0.9983)between the fluorescence intensity of multifunctional microspheres and the concentration of Hg^(2+)was constructed with a satisfactory detection limit of 2.3×10^(-8)mol·L^(-1).Their fluorescence response in the presence of Hg^(2+)is found to be almost reversible when treated by EDTA solution.Moreover,these pyrene-functionalized magnetic silica nanospheres can efficiently remove Hg^(2+)in aqueous solution and easily separated by appling an external magnetic field.These results indicate that functionalized core-shell magnetic silica microspheres are potentially promising materials for simultaneously detecting and removing environmental pollutants.
基金Project(20775010)supported by the National Natural Science Foundation of ChinaProject(208095)supported by the Key Project ofMinistry of Education,China+1 种基金Project(07A006)supported by the Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(07JJ3020)supported by Hunan Provincial Natural Science Foundation of China
文摘A novel technique of immobilizing indicator dyes by electrostatic adsorption and covalent bonding to fabricate optical sensors was developed.3-Amino-9-ethylcarbazole(AEC)was attached to the outmost surface of quartz glass slide via aminosilanizing the slide,crosslinking chitosan,adsorbing Au nanoparticle,self-assembling HS(CH2)11OH,and coupling AEC.Thus, an AEC-immobilized optical sensor was obtained.The sensor exhibits a wide linear response range from 7.0×10- 7to 1.0×10 -4 mol/L and a correlation coefficient of 0.995 9 for the detection of 2-nitrophenol.The detection limit and response time of the sensor are 1.0×10- 7mol/L and less than 10 s,respectively.The fluorescence intensity of the used sensor can be restored to the blank value by simply rinsing with blank buffer.A very effective matrix for immobilizing indicator dye is provided by the proposed technique, which is adaptable to other indicator dyes with amino groups besides AEC.
基金supported by the National Natural Science Foundation of China(61372069)and the"111"Project(B08038)
文摘In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space division multiple access, and a sensor node uses a modulating retro-reflector for communication. Thus while a random sampling matrix is used to guide the establishment of links between head cluster and sensor nodes, the random linear projection is accomplished. To establish multiple links at the same time, an optical space division multiple access antenna is designed. It works in fixed beams switching mode and consists of optic lens with a large field of view（FOV）, fiber array on the focal plane which is used to realize virtual channels segmentation, direction of arrival sensor, optical matrix switch and controller. Based on the angles of nodes＇ laser beams, by dynamically changing the route, optical matrix switch actualizes the multi-beam full duplex tracking receiving and transmission. Due to the structure of fiber array, there will be several fade zones both in the focal plane and in lens＇ FOV. In order to lower the impact of fade zones and harmonize multibeam, a fiber array adjustment is designed. By theoretical, simulated and experimental study, the antenna＇s qualitative feasibility is validated.
基金Projects(51908071,51708071)supported by National Natural Science Foundation of ChinaProject(2020JJ5975)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(18C0194)supported by the Scientific Research Project of Education Department of Hunan Province,ChinaProject(kfj190301)supported by Open Fund of Key Laboratory of Road Structure and Material of Ministry of Transport(Changsha University of Science&Technology),China。
文摘In order to reveal the changing law of the mechanical response of asphalt pavements under the action of vehicle load and provide references for the design of durable pavements,three typical asphalt pavement structures with flexible base(S1),combined base(S2),and semi-rigid base(S3)were selected to perform field strain tests under static and dynamic load using the fiber Bragg grating optical sensing technology.The changing characteristics of the strain field along the horizontal and depth directions of pavements were analyzed.The results indicate that the most unfavorable asphalt pavement layers were the upper-middle surface layer and the lower base layer.In addition,the most unfavorable loading positions on the surface layer and the base layer were the center of wheel load and the gap center between two wheels,respectively.The most unfavorable layer of the surface layers gradually moved from the lower layer to the upper layer with the increase of base layer modulus.The power function relationships between structural layer strain and vehicle speed were revealed.The semi-rigid base asphalt pavement was the most durable pavement type,since its strain value was lower compared to those of the other structures.
文摘Magneto optic(MO) fiber current sensors utility the Faraday effect of magneto op tic materials to sensing the magnetic(current)fields.The optical fiber sensors(O FS)offer great advantages of simple structure,high reliability,high accuracy and sensibility,immunity to electromagnetic interference.They are the most promised method to substitute the conventional current transducers(CTs),much attentions were focused on both domestic and abroad.Magneto optic properties of Faraday se n sing element have much affect on the performance of the optical fiber current se nsor.For used in the sensor system,MO materials with magneto optic characterist i cs of large Faraday rotation(FR)angle θ f ,low temperature sensibility,and suitable saturation field were general demanded. Development of MO materials is one of the most important problems of optical fiber current sensor research. In this paper,one mixed doped Bi substituted yttrium iron garnet crystal BiYb:Y I G, which has large and temperature stable FR angle,was grown from high temperatu re flux.By taking PbO+PbF 2 as the main flux,under the compositions of molar ra tio Y 2O 3:Yb 2O 3:Bi 2O 3:Fe 2O 3:(PbO+PbF 2+B 2O 3+CaCO 3)=7.64:1. 04:1.74:20.78:78:68.8,crystals of quite good quality were grown from melt flux,t he largest one has the size of 22mm×15mm×12mm.Magneto optic proprieties of Fa raday rotation angle and optical absorption spectrum of the BiYb:YIG crystal,expecial ly Y 2.289 Yb 0.246 Bi 0.465 Fe 5O 12 ,in the range of 0.7 1.9 μm waveband were measured.At λ =1.55μm,the BiYb:YIG crystal has special Fa raday rotation angle of -404deg/cm,temperature coefficient 4.2×10 -6 K -1 ,optical absorption coefficient 3.6cm -1 ,and figure of merit 25.8deg/dB . The results indicate that substituted with Bi 3+ can largely improve the Fa raday rotation of rear earth iron garnets.Because Faraday rotation angles of Yb 3Fe 5O 12 and Y 3Fe 5O 12 have opposite temperature dependency,ut ility the compensation effect of mix doped,co doped with some other ions,such a s Yb 3+ ,would decrease the temperature dependency of Bi substituted garnet. So the garnet crystal BiYb:YIG has high and temperature stable Faraday rotation an gle,very suitable to be used as Faraday effect materials for high sensibility an d temperature stable Optical fiber current sensors.Using BiYb:YIG as Faraday rot ation cell,a hybrid bulk crystal optical fiber current sensor was proposed and t ests under direct current(DC) and 50Hz alternating current(AC).The performance c haracteristics of the sensors system were:DC measurement,sensibility 0.01A, l inea rity 1.1%;AC measurement,sensibility 9.5A/mV ,accuracy ±1%,linearity 1.1%,dynam ic range 40dB.In conclusion,Faraday effect magneto optic optical fiber current sensors have higher sensibility and accuracy than conventional CTs.
