The resonator fiber optic gyro (R-FOG) ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-F...The resonator fiber optic gyro (R-FOG) ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-FOG is set up using phase modulation spectroscopy. First,the demodulation curve is obtained using a lock-in amplifier. From the demodulation signal,a gyro dynamic range of ± 4.2rad/s is obtained. Then,using different phase modulation frequencies,the open-loop gyro output signal is measured when the gyro is rotated clockwise or counterclockwise. The bias drift as a function of time is also measured. The fluctuation of the output over 5s is about 0.02rad/s. The drift can be reduced by taking countermeasures against system noise.展开更多
A new photodetector--bipolar junction photogate transistor is presented for CMOS image sensor and its analytical model is also established.With the technical parameter of the 0.6μm CMOS process,the bipolar junction p...A new photodetector--bipolar junction photogate transistor is presented for CMOS image sensor and its analytical model is also established.With the technical parameter of the 0.6μm CMOS process,the bipolar junction photogate transistor is analyzed and simulated.The simulated results illustrate that the bipolar junction photogate transistor has the similar characteristics of the traditional photogate transistor.The photocurrent density of the bipolar junction photogate transistor increases exponentially with the incidence light power due to introducing the injection p+n junction.Its characteristic of blue response is rather improved compared to the traditional photogate transistor that benefits to increase the color photograph made up of the red,the green,and the blue.展开更多
Dynamic detection based on optics sensors and ranging radars is a new method to detect the luminous intensity of flight aid lights. The optics sensors can get the illumination information of each light, the ranging ra...Dynamic detection based on optics sensors and ranging radars is a new method to detect the luminous intensity of flight aid lights. The optics sensors can get the illumination information of each light, the ranging radar gets the distance information, and then data amalgamation technology is used to compute the luminous intensity of each light. A method to modify the errors of this dynamic detection system is presented. It avoids the accumulation error and measurement carrier’s excursion error by using peak value detection based on optics sensors to estimate the accurate position of each light, then to modify the lights’ lengthways distance information and transverse position information. The performance of the detection and ranging system is validated by some experiments and shown in pictures.展开更多
Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h: to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class curren...Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h: to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class current collection performance evaluation methods that have been developed and demonstrated by Korea. Specifically, this paper reports details of the video-based monitoring techniques that have been adopted to inspect the stability of overhead contact line (OCL) components at 400 km.h-1 without direct contact with any components of the power supply system. Unlike conventional OCL monitoring systems, which detect contact wire positions using either laser sensors or line cameras, the developed system measures parameters in the active state by video data. According to experimental results that were obtained at a field-test site established at a commercial line, it is claimed that the proposed mea- surement system is capable of effectively measuring OCL parameters.展开更多
An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are...An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber. The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback,the system is available with high reliable, outstanding accuracy and repeatability.展开更多
An all optical fiber gas sensor is presented to detect the concentration of NH3 and CO. Based on the spectral absorption, The wideband light source is used to reflect two narrowband spectra by fiber grating of differe...An all optical fiber gas sensor is presented to detect the concentration of NH3 and CO. Based on the spectral absorption, The wideband light source is used to reflect two narrowband spectra by fiber grating of different duty. and piezoelectric ceramics to obtain narrowband output light. The high sensitivity detection can be measured from the second harmonic signal. The two narrowband spectra are corresponding to the absorption spectra of NH3 and CO. Concentration detection are realized by the detection of variety of light intensity. Sensitivity is proved and cost is reduced.展开更多
In order to achieve the manipulator's soft grasp function, the key is to have slip sensors with fine performance. Depending on the elastomer and photoelectric elements installed in the hand, the sensor transforms ...In order to achieve the manipulator's soft grasp function, the key is to have slip sensors with fine performance. Depending on the elastomer and photoelectric elements installed in the hand, the sensor transforms the slippage between the grasped object and the robot's hand to electric signal, thus the slippage can be detected. It will cause elastomers' micro-vibration when the object is slippage. Based on the vibration theory, dynamic theory, light intensity theory and elastic deformation theory, derived is the conclusion that the object's slippage acceleration relativing to the robot's hand has linear relationship with the photoelectric elements' output voltage's differential, and then the model for slippage distinguishing is set up.展开更多
A novel type of two-dimensional damage assessment system for real time monitoring the structural health of composite structure is described. The configuration of the embedded fiberoptic sensor array and the model of t...A novel type of two-dimensional damage assessment system for real time monitoring the structural health of composite structure is described. The configuration of the embedded fiberoptic sensor array and the model of the artificial neural network (ANN) are discussed. The experimental system and results show that the system can monitor a damage of structures with potential application in areas such as space aeronautics, civil engineering, etc.展开更多
Herein we report a highly sensitive filter-less fluorescence detection method using an APD (avalanche photodiode). Experimental measurements using the proposed APD-based highly sensitive fluorescence detection metho...Herein we report a highly sensitive filter-less fluorescence detection method using an APD (avalanche photodiode). Experimental measurements using the proposed APD-based highly sensitive fluorescence detection method exhibits the sensing capability to detect an excitation light and a fluorescence light without band pass filter or grating. The principle of this APD-based highly fluorescence detection method is used the varying multiplication ratio that is decided by wavelength. The wavelength controls running distance of photo-excited carrier by absorption coefficients, and this element decide multiplication ratio on fixed high electrical field. In fluorescence detection, they use two types of light: excitation light and fluorescence light. These lights have different wavelengths and make different multiplication ratio as well. Thus this method can separate two types of light easily by using multiplication ratios of APD without band pass filters/gratings. In this experiment, the excitation light is LED (light emitting diode) and fluorescence light occurs from FITC (fluorescein isothiocyanate) with ethanol. The FITC concentration changes from 0.1 μmol/L to 10 mmol/L. In this measurement circuit, we employ APD (S2385), power supply voltage, and pico ampere current meter. As a result, these lights are correctly separated by using multiplication ratio with calculation at every concentration FITCs.展开更多
Objective To explore the relationship between the receptor temperature and moxibustion distance of mild moxibustion, and provide evidence for clinical moxibustion distance. Methods Mild moxibustion was carried out for...Objective To explore the relationship between the receptor temperature and moxibustion distance of mild moxibustion, and provide evidence for clinical moxibustion distance. Methods Mild moxibustion was carried out for 15min by adopting moxibustion shelf, and the moxibustion ash was shook off automatically for once every 3 min. The distance between moxa stick and temperature sensor was set as 2 cm, 3 cm, 4 cm and 5 cm, respectively, by ruler. The temperature was recorded for once every 2 s with photothermal detection system for moxibustion combustion to form a temperature profile. The initial temperature, maximum temperature and average temperature were observed, and the experimental data were analyzed via SPSS18.0 statistical software. Results The initial receptor temperature was (25.33±0.29) ℃ when the moxibustion distance was 2 cm, (25.29±0.05) ℃ when the moxibustion distance was 3 cm, (25.43±0.17) ℃ when the moxibustion distance was 4cm, and (25.16±0.22) ℃ when the moxibustion distance was 5 cm, respectively. The maximum temperature was (74.96±1.20) ℃ when the moxibustion distance was 2 cm, (51.70±0.74) ℃ when the moxibustion distance was 3 cm, (49.33±0.40) ℃ when the moxibustion distance was 4 cm, and (42.50±0.26) ℃ when the moxibustion distance was 5 cm, respectively. The average temperature was (62.40±7.84) ℃-(62.68±7.58) ℃ when the moxibustion distance was 2 cm, (44.77±3.31) ℃-(45.11±3.21) ℃ when the moxibustion distance was 3 cm, (42.72+3.86) ℃-(43.12±3.54) ℃ when the moxibust-ion distance was 4 cm, and (38.45±1.67) ℃-(38.50±1.63) ℃ when the moxibustion distance was 5 cm, respectively. The temperature curve showed that the fluctuation range was the maximum when the moxibustion distance was 2 cm, larger when the moxibustion distance was 3 cm, smaller when the moxibustion distance was 4 cm, and minimum when the moxibustion distance was 5 cmo There was no significant difference in the initial temperature of mild moxibustion at different distances, however, the maximum temperature, average temperature and the fluctuation range of temperature curve were closely related to the moxibustion distance. Conclusion The nearer the distance is, the higher the maximum temperature and average temperature as well as the larger the fluctuation range will be, and the farther the distance is, the lower the maximum temperature and average temperature as well as the smaller the fluctuation range will be. Accordin8 to preliminary analysis, the temperature will be the most suitable when the moxibust-ion distance is 3 cm-4 cm.展开更多
Acoustic emission monitoring is often used in the diagnosis of electrical and mechanical incipient faults in the high voltage apparatus. Partial discharges are a major source of insulation failure in electric power tr...Acoustic emission monitoring is often used in the diagnosis of electrical and mechanical incipient faults in the high voltage apparatus. Partial discharges are a major source of insulation failure in electric power transformers, and the differentiation from other sources of acoustic emission is of the utmost importance. This paper reports the development of a new sensor concept - a fiber laser sensor based on a phase-shifted chirped fiber grating - for the acoustic emission detection of incipient faults in oil-filled power transformers. These sensors can be placed in the inner surface of the transformer tank wall, not affecting the insulation integrity of the structure and improving fault detection and location. The performance of the sensing head is characterized and compared for different surrounding media: air, water, and oil. The results obtained indicate the feasibility of this sensing approach for the industrial development of practical solutions.展开更多
To realize highly selective relay recognition of Fe3+ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor (L) was designed and synthesized. Sensor L displays rapid, highly selective, and sensitiv...To realize highly selective relay recognition of Fe3+ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor (L) was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3+ in H2O/DMSO (1:1, v/v) solutions. The in stitu-generated L-Fe^3+ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3+ displacement approach. The detection limits of sensor L to Fe^3+ and L-Fe^3+complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3+, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3+ and H2PO4 anion detection in aqueous media.展开更多
The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The result...The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The results showed that the FBG strain sensor with the wide measuring range could measure the stress variation accurately during the support process of the gateway retained along the goaf and could provide the basis to further optimize the support structure and to determine the support plan of the gateway retained along the goaf. The FBG micro-seismic sensors were used in Xinglong Mine to detect the micro-seismic signal. The signals were well received and analyzed to determine the location and energy level of the source of the micro-seismic event warning. The FBG sensors and detecting system show a significant potential for micro-seismic detection and geological disasters detection.展开更多
The development of sensors for selective detection of cyanide ion(CN^-) is an important mission to accomplish because of the versatility and toxicity of CN^-. In the present work, an "ensemble"-based colorim...The development of sensors for selective detection of cyanide ion(CN^-) is an important mission to accomplish because of the versatility and toxicity of CN^-. In the present work, an "ensemble"-based colorimetric and fluorescent sensor(L2-Zn^(2+)) for CN^-ion has been developed. The addition of cyanide ions removed Zn^(2+) from the ensemble(L2-Zn^(2+)) in aqueous medium, resulting in a color change of the solution from red to buff and a "turn-on" fluorescent response. Also, the sensitivity of both the fluorescenceand colorimetric-based assay is below the maximum allowable level of cyanide ions in drinking water set by the World Health Organization. In addition, test strips, which served as convenient and efficient CN^- test kits, were fabricated based on the sensor.Notably, the selective detection of cyanide with L2-Zn^(2+) for practical application was also performed in sprouting potatoes.展开更多
In this paper, a partial discharge detection system is proposed using an optical fiber Fabry-Perot(FP) interferometric sensor, which is fabricated by photolithography. SU-8 photoresist is employed due to its low Young...In this paper, a partial discharge detection system is proposed using an optical fiber Fabry-Perot(FP) interferometric sensor, which is fabricated by photolithography. SU-8 photoresist is employed due to its low Young's modulus and potentially high sensitivity for ultrasound detection. The FP cavity is formed by coating the fiber end face with two layers of SU-8 so that the cavity can be controlled by the thickness of the middle layer of SU-8. Static pressure measurement experiments are done to estimate the sensing performance. The results show that the SU-8 based sensor has a sensitivity of 154.8 nm/kP a, which is much higher than that of silica based sensor under the same condition. Moreover, the sensor is demonstrated successfully to detect ultrasound from electrode discharge.展开更多
A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polariz...A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polarization variation of signal light and only responses to rapid polarization change caused by external vibration interference. Based on the sensing signal characteristics, the location of polarization disturbance point can be detected accurately. Experiments on polarization controller simulation and actual vibration detection show that a higher localization accuracy better than 1% is successfully obtained in 13.8 kin, 21.2 km and 35.8 km sensing fibers systems.展开更多
A brief review on biconical tapered fiber sensors for biosensing applications is presented. A variety of configurations and formats of this sensor have been devised for label free biosensing based on measuring small r...A brief review on biconical tapered fiber sensors for biosensing applications is presented. A variety of configurations and formats of this sensor have been devised for label free biosensing based on measuring small refractive index changes. The biconical nonadiabatic tapered optical fiber offers a number of favorable properties for optical sensing, which have been exploited in several biosensing applications, including cell, protein, and DNA sensors. The types of these sensors present a low-cost fiber biosensor featuring a miniature sensing probe, label-free direct detection, and high sensitivity.展开更多
This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based biosensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed o...This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based biosensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed on the basis of the light addressable potentiometric sensor (LAPS), in which rat OSNs were cultured on the surface of LAPS chip and served as sensing elements. LY294002, the specific inhibitor of phosphatidylinositol 3-kinase (PI3K), was used to enhance the responses of OSNs to odorants. The responses of OSNs to odorants with and without the treatment of LY294002 were recorded by LAPS. The results show that the enhancive effect of LY294002 was recorded efficiently by LAPS and the responses of this OSNs-LAPS hybrid biosensor were enhanced by LY294002 by about 1.5-fold. We conclude that this method can enhance the responses of OSNs-LAPS hybrid biosensors, which may provide a novel strategy for the bioelectrical signal monitor of OSNs in biosensors. It is also suggested that this strategy may be applicable to other kinds of OSNs-based biosensors for cellular activity detection, such as microelectrode array (MEA) and field effect transistor (FET).展开更多
文摘The resonator fiber optic gyro (R-FOG) ,which utilizes a resonance frequency change due to the Sagnac effect,is a promising candidate for the next generation inertial rotation sensor. In this study, an open-loop R-FOG is set up using phase modulation spectroscopy. First,the demodulation curve is obtained using a lock-in amplifier. From the demodulation signal,a gyro dynamic range of ± 4.2rad/s is obtained. Then,using different phase modulation frequencies,the open-loop gyro output signal is measured when the gyro is rotated clockwise or counterclockwise. The bias drift as a function of time is also measured. The fluctuation of the output over 5s is about 0.02rad/s. The drift can be reduced by taking countermeasures against system noise.
文摘A new photodetector--bipolar junction photogate transistor is presented for CMOS image sensor and its analytical model is also established.With the technical parameter of the 0.6μm CMOS process,the bipolar junction photogate transistor is analyzed and simulated.The simulated results illustrate that the bipolar junction photogate transistor has the similar characteristics of the traditional photogate transistor.The photocurrent density of the bipolar junction photogate transistor increases exponentially with the incidence light power due to introducing the injection p+n junction.Its characteristic of blue response is rather improved compared to the traditional photogate transistor that benefits to increase the color photograph made up of the red,the green,and the blue.
基金Science and Technology Development Project Item of Tianjin(06YFGZGX00800)Science and Technology Item of CAAC(MY0517416)
文摘Dynamic detection based on optics sensors and ranging radars is a new method to detect the luminous intensity of flight aid lights. The optics sensors can get the illumination information of each light, the ranging radar gets the distance information, and then data amalgamation technology is used to compute the luminous intensity of each light. A method to modify the errors of this dynamic detection system is presented. It avoids the accumulation error and measurement carrier’s excursion error by using peak value detection based on optics sensors to estimate the accurate position of each light, then to modify the lights’ lengthways distance information and transverse position information. The performance of the detection and ranging system is validated by some experiments and shown in pictures.
文摘Various technologies have recently been developed for high-speed railways, in order to boost commercial speeds from 300 km.h: to 400 km.h-1. Among these technologies, this paper introduces the 400 km-h-1 class current collection performance evaluation methods that have been developed and demonstrated by Korea. Specifically, this paper reports details of the video-based monitoring techniques that have been adopted to inspect the stability of overhead contact line (OCL) components at 400 km.h-1 without direct contact with any components of the power supply system. Unlike conventional OCL monitoring systems, which detect contact wire positions using either laser sensors or line cameras, the developed system measures parameters in the active state by video data. According to experimental results that were obtained at a field-test site established at a commercial line, it is claimed that the proposed mea- surement system is capable of effectively measuring OCL parameters.
文摘An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber. The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback,the system is available with high reliable, outstanding accuracy and repeatability.
文摘An all optical fiber gas sensor is presented to detect the concentration of NH3 and CO. Based on the spectral absorption, The wideband light source is used to reflect two narrowband spectra by fiber grating of different duty. and piezoelectric ceramics to obtain narrowband output light. The high sensitivity detection can be measured from the second harmonic signal. The two narrowband spectra are corresponding to the absorption spectra of NH3 and CO. Concentration detection are realized by the detection of variety of light intensity. Sensitivity is proved and cost is reduced.
基金National Natural Science Foundation of China(50475060)
文摘In order to achieve the manipulator's soft grasp function, the key is to have slip sensors with fine performance. Depending on the elastomer and photoelectric elements installed in the hand, the sensor transforms the slippage between the grasped object and the robot's hand to electric signal, thus the slippage can be detected. It will cause elastomers' micro-vibration when the object is slippage. Based on the vibration theory, dynamic theory, light intensity theory and elastic deformation theory, derived is the conclusion that the object's slippage acceleration relativing to the robot's hand has linear relationship with the photoelectric elements' output voltage's differential, and then the model for slippage distinguishing is set up.
文摘A novel type of two-dimensional damage assessment system for real time monitoring the structural health of composite structure is described. The configuration of the embedded fiberoptic sensor array and the model of the artificial neural network (ANN) are discussed. The experimental system and results show that the system can monitor a damage of structures with potential application in areas such as space aeronautics, civil engineering, etc.
文摘Herein we report a highly sensitive filter-less fluorescence detection method using an APD (avalanche photodiode). Experimental measurements using the proposed APD-based highly sensitive fluorescence detection method exhibits the sensing capability to detect an excitation light and a fluorescence light without band pass filter or grating. The principle of this APD-based highly fluorescence detection method is used the varying multiplication ratio that is decided by wavelength. The wavelength controls running distance of photo-excited carrier by absorption coefficients, and this element decide multiplication ratio on fixed high electrical field. In fluorescence detection, they use two types of light: excitation light and fluorescence light. These lights have different wavelengths and make different multiplication ratio as well. Thus this method can separate two types of light easily by using multiplication ratios of APD without band pass filters/gratings. In this experiment, the excitation light is LED (light emitting diode) and fluorescence light occurs from FITC (fluorescein isothiocyanate) with ethanol. The FITC concentration changes from 0.1 μmol/L to 10 mmol/L. In this measurement circuit, we employ APD (S2385), power supply voltage, and pico ampere current meter. As a result, these lights are correctly separated by using multiplication ratio with calculation at every concentration FITCs.
基金Supported by National Basic Research Program of China:2015CB554502Research Study and Innovative Experimental Planning Project of Hunan Province Undergraduates:NO221+2 种基金Doctor Scientific Research Fund Project of Hunan University of Chinese Medicine:9982-1001-014Popularizing Project of State Administration of Traditional Chinese Medicine of ChinaProject of China Postdoctoral Science Foundation:2015M580689
文摘Objective To explore the relationship between the receptor temperature and moxibustion distance of mild moxibustion, and provide evidence for clinical moxibustion distance. Methods Mild moxibustion was carried out for 15min by adopting moxibustion shelf, and the moxibustion ash was shook off automatically for once every 3 min. The distance between moxa stick and temperature sensor was set as 2 cm, 3 cm, 4 cm and 5 cm, respectively, by ruler. The temperature was recorded for once every 2 s with photothermal detection system for moxibustion combustion to form a temperature profile. The initial temperature, maximum temperature and average temperature were observed, and the experimental data were analyzed via SPSS18.0 statistical software. Results The initial receptor temperature was (25.33±0.29) ℃ when the moxibustion distance was 2 cm, (25.29±0.05) ℃ when the moxibustion distance was 3 cm, (25.43±0.17) ℃ when the moxibustion distance was 4cm, and (25.16±0.22) ℃ when the moxibustion distance was 5 cm, respectively. The maximum temperature was (74.96±1.20) ℃ when the moxibustion distance was 2 cm, (51.70±0.74) ℃ when the moxibustion distance was 3 cm, (49.33±0.40) ℃ when the moxibustion distance was 4 cm, and (42.50±0.26) ℃ when the moxibustion distance was 5 cm, respectively. The average temperature was (62.40±7.84) ℃-(62.68±7.58) ℃ when the moxibustion distance was 2 cm, (44.77±3.31) ℃-(45.11±3.21) ℃ when the moxibustion distance was 3 cm, (42.72+3.86) ℃-(43.12±3.54) ℃ when the moxibust-ion distance was 4 cm, and (38.45±1.67) ℃-(38.50±1.63) ℃ when the moxibustion distance was 5 cm, respectively. The temperature curve showed that the fluctuation range was the maximum when the moxibustion distance was 2 cm, larger when the moxibustion distance was 3 cm, smaller when the moxibustion distance was 4 cm, and minimum when the moxibustion distance was 5 cmo There was no significant difference in the initial temperature of mild moxibustion at different distances, however, the maximum temperature, average temperature and the fluctuation range of temperature curve were closely related to the moxibustion distance. Conclusion The nearer the distance is, the higher the maximum temperature and average temperature as well as the larger the fluctuation range will be, and the farther the distance is, the lower the maximum temperature and average temperature as well as the smaller the fluctuation range will be. Accordin8 to preliminary analysis, the temperature will be the most suitable when the moxibust-ion distance is 3 cm-4 cm.
文摘Acoustic emission monitoring is often used in the diagnosis of electrical and mechanical incipient faults in the high voltage apparatus. Partial discharges are a major source of insulation failure in electric power transformers, and the differentiation from other sources of acoustic emission is of the utmost importance. This paper reports the development of a new sensor concept - a fiber laser sensor based on a phase-shifted chirped fiber grating - for the acoustic emission detection of incipient faults in oil-filled power transformers. These sensors can be placed in the inner surface of the transformer tank wall, not affecting the insulation integrity of the structure and improving fault detection and location. The performance of the sensing head is characterized and compared for different surrounding media: air, water, and oil. The results obtained indicate the feasibility of this sensing approach for the industrial development of practical solutions.
基金supported by the National Natural Science Foundation of China(21064006,21161018,21262032)the Natural Science Foundation of Gansu Province(1010RJZA018)+1 种基金the Program for Changjiang ScholarsInnovative Research Teams in Universities of the Ministry of Education of China(IRT1177)
文摘To realize highly selective relay recognition of Fe3+ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor (L) was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3+ in H2O/DMSO (1:1, v/v) solutions. The in stitu-generated L-Fe^3+ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3+ displacement approach. The detection limits of sensor L to Fe^3+ and L-Fe^3+complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3+, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3+ and H2PO4 anion detection in aqueous media.
文摘The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The results showed that the FBG strain sensor with the wide measuring range could measure the stress variation accurately during the support process of the gateway retained along the goaf and could provide the basis to further optimize the support structure and to determine the support plan of the gateway retained along the goaf. The FBG micro-seismic sensors were used in Xinglong Mine to detect the micro-seismic signal. The signals were well received and analyzed to determine the location and energy level of the source of the micro-seismic event warning. The FBG sensors and detecting system show a significant potential for micro-seismic detection and geological disasters detection.
基金supported by the National Natural Science Foundation of China(21662031,21661028,21574104,21262032)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(IRT 15R56)
文摘The development of sensors for selective detection of cyanide ion(CN^-) is an important mission to accomplish because of the versatility and toxicity of CN^-. In the present work, an "ensemble"-based colorimetric and fluorescent sensor(L2-Zn^(2+)) for CN^-ion has been developed. The addition of cyanide ions removed Zn^(2+) from the ensemble(L2-Zn^(2+)) in aqueous medium, resulting in a color change of the solution from red to buff and a "turn-on" fluorescent response. Also, the sensitivity of both the fluorescenceand colorimetric-based assay is below the maximum allowable level of cyanide ions in drinking water set by the World Health Organization. In addition, test strips, which served as convenient and efficient CN^- test kits, were fabricated based on the sensor.Notably, the selective detection of cyanide with L2-Zn^(2+) for practical application was also performed in sprouting potatoes.
基金supported by the National Basic Research Program of China(No.2012CB723405)the Science and Technology Commission of Shanghai Municipality(Nos.13510500300,14DZ1201403 and 14511105602)
文摘In this paper, a partial discharge detection system is proposed using an optical fiber Fabry-Perot(FP) interferometric sensor, which is fabricated by photolithography. SU-8 photoresist is employed due to its low Young's modulus and potentially high sensitivity for ultrasound detection. The FP cavity is formed by coating the fiber end face with two layers of SU-8 so that the cavity can be controlled by the thickness of the middle layer of SU-8. Static pressure measurement experiments are done to estimate the sensing performance. The results show that the SU-8 based sensor has a sensitivity of 154.8 nm/kP a, which is much higher than that of silica based sensor under the same condition. Moreover, the sensor is demonstrated successfully to detect ultrasound from electrode discharge.
基金supported by the Natioral Natural Suience Foundation of China (No.60736035)the National Basic Research Program of China (No.2010CB327603)
文摘A novel distributed optical fiber vibration sensing system based on polarization detection is proposed and demonstrated. A Faraday rotator mirror is employed at the end of the system, which eliminates the slow polarization variation of signal light and only responses to rapid polarization change caused by external vibration interference. Based on the sensing signal characteristics, the location of polarization disturbance point can be detected accurately. Experiments on polarization controller simulation and actual vibration detection show that a higher localization accuracy better than 1% is successfully obtained in 13.8 kin, 21.2 km and 35.8 km sensing fibers systems.
文摘A brief review on biconical tapered fiber sensors for biosensing applications is presented. A variety of configurations and formats of this sensor have been devised for label free biosensing based on measuring small refractive index changes. The biconical nonadiabatic tapered optical fiber offers a number of favorable properties for optical sensing, which have been exploited in several biosensing applications, including cell, protein, and DNA sensors. The types of these sensors present a low-cost fiber biosensor featuring a miniature sensing probe, label-free direct detection, and high sensitivity.
基金supported by the National Natural Science Foundation ofChina (No. 60725102)the Natural Science Foundation of Zhejiang Province, China (No. R205505)
文摘This paper presents a novel strategy for the response enhancement of olfactory sensory neurons (OSNs)-based biosensors by monitoring the enhancive responses of OSNs to odorants. An OSNs-based biosensor was developed on the basis of the light addressable potentiometric sensor (LAPS), in which rat OSNs were cultured on the surface of LAPS chip and served as sensing elements. LY294002, the specific inhibitor of phosphatidylinositol 3-kinase (PI3K), was used to enhance the responses of OSNs to odorants. The responses of OSNs to odorants with and without the treatment of LY294002 were recorded by LAPS. The results show that the enhancive effect of LY294002 was recorded efficiently by LAPS and the responses of this OSNs-LAPS hybrid biosensor were enhanced by LY294002 by about 1.5-fold. We conclude that this method can enhance the responses of OSNs-LAPS hybrid biosensors, which may provide a novel strategy for the bioelectrical signal monitor of OSNs in biosensors. It is also suggested that this strategy may be applicable to other kinds of OSNs-based biosensors for cellular activity detection, such as microelectrode array (MEA) and field effect transistor (FET).