The seafloor vector magnetometer is an effective tool for marine geomagnetic surveys and seafloor magnetotelluric(MT)detection.However,the noise,power consumption,cost,and volume characteristics of existing seafloor v...The seafloor vector magnetometer is an effective tool for marine geomagnetic surveys and seafloor magnetotelluric(MT)detection.However,the noise,power consumption,cost,and volume characteristics of existing seafloor vector magnetometers are insufficient for practical use.Therefore,a low-noise,low-power-consumption seafloor vector magnetometer that can be used for data acquisition of deep-ocean geomagnetic vector components is developed and presented.A seafloor vector magnetometer mainly consists of a fluxgate sensor,data acquisition module,acoustic release module,glass sphere,frame,burn-wire release,and anchor.A new low-noise data acquisition module and a fluxgate sensor greatly reduce power consumption.Furthermore,compact size is achieved by integrating an acoustic telemetry module and replacing the acoustic release with an external burn-wire release.The new design and magnetometer characteristics reduce the volume of the instrument and the cost of hardware considerably,thereby improving the integrity and deployment efficiency of the equipment.Theoretically,it can operate for 90 days underwater at a maximum depth of 6000 m.The seafloor vector magnetometer was tested in the South China Sea and the Philippine Sea and obtained high-quality geomagnetic data.The deep-water environment facilitates magnetic field data measurements,and the magnetometer has an approximate noise level of 10 pT/rt(Hz)@1 Hz,a peak-to-peak value error of 0.2 nT,and approximate power consumption of 200 mW.The fluxgate sensor can measure the magnetic field in the lower frequency band and realize geomagnetic field measurements over prolonged periods.展开更多
A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT appli...A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT applications by introducing a comparative between different low power wireless communication techniques such as ZigBee, Low Power Wi-Fi, 6LowPAN, LPWA and their modules to conserve power and longing the life for the IoT network sensors. The approach of the study is in term of protocol used and the particular module that achieve that protocol. The candidate protocols are classified according to the range of connectivity between sensor nodes. For short ranges connectivity the candidate protocols are ZigBee, 6LoWPAN and low power Wi-Fi. For long connectivity the candidate is LoRaWAN protocol. The results of the study demonstrate that the choice of module for each protocol plays a vital role in battery life due to the difference of power consumption for each module/protocol. So, the evaluation of protocols with each other depends on the module used.展开更多
According to the transit-time difference measurement method,we proposed a design scheme of ultrasonic heat meter based on TDC-GP21.The measurement unit TDC-GP21 mainly completes transit-time measurement and inlet,outl...According to the transit-time difference measurement method,we proposed a design scheme of ultrasonic heat meter based on TDC-GP21.The measurement unit TDC-GP21 mainly completes transit-time measurement and inlet,outlet temperature measurement functions.Control unit and data processing unit based on MSP430F4152 of TI corporation complete functions including peripherals control,data analysis,temperature compensation algorithm,flow pattern compensation algorithm and low power consumption control.The design meets the Town Construction Professional Standard CJ 128-2007,and furthermore,some performances can be improved.展开更多
The miniaturization and endurance of wearable devices have been the research direction for a long time.With the development of nanotechnology and the emergence of microelectronics products,people have explored many ne...The miniaturization and endurance of wearable devices have been the research direction for a long time.With the development of nanotechnology and the emergence of microelectronics products,people have explored many new strategies that may be applied to wearable devices.In this overview,we will summarize the recent research of wearable devices in these two directions,and summarize some available related technologies.展开更多
There is a great demand for high-performance hydrogen sulfide(H_(2)S)sensors with low operating temperatures.Ag/In_(2)O_(3)hexagonal tubes with different proportions were prepared by the calcination of Ag+-impregnated...There is a great demand for high-performance hydrogen sulfide(H_(2)S)sensors with low operating temperatures.Ag/In_(2)O_(3)hexagonal tubes with different proportions were prepared by the calcination of Ag+-impregnated indium-organic frameworks(CPP-3(In)),and the developed sensors exhibit enhanced gas-sensing performance toward H_(2)S.Gas sensing measurements indicate that the response of Ag/In_(2)O_(3)(2.5 wt%)sensor to 5 ppm H_(2)S has the highest response(119),operated at 70℃.The Ag/In_(2)O_(3)(2.5 wt%)based sensor exhibits short response time(20 s),low detection limit(300 ppb),and good selectivity toward H_(2)S gas,which imply that the CPP-3(In)-derived Ag/In_(2)O_(3)hexagonal tube is a promising candidate to be constructed a low power-consumption H_(2)S sensor.展开更多
In an acousto-optic modulator,the electrode shape plays an important role in performance,since it affects the distribution of the acoustic field.The acousto-optic modulator based on the conventional rectangular electr...In an acousto-optic modulator,the electrode shape plays an important role in performance,since it affects the distribution of the acoustic field.The acousto-optic modulator based on the conventional rectangular electrode has the problems of low energy efficiency and small modulation bandwidth due to an imperfect acoustic field.In this paper,a new serrated periodic electrode has been proposed for using acousto-optic modulator transducers.The proposed electrode has the following advantages.By using serrated periodic electrodes to suppress the sidelobes,the collimation of the acoustic field in the direction perpendicular to the light incidence is improved.This makes the acousto-optic modulator have a stable diffraction efficiency fluctuation and high energy efficiency.In addition,the electrode has a large divergence angle in the direction of light incidence,so a large bandwidth can be obtained.The simulations and experiments demonstrate that the serrated periodic electrode has an increased bandwidth and high energy efficiency.展开更多
All-optical devices,which are utilized to process optical signals without electro-optical conversion,play an essential role in the next generation ultrafast,ultralow power-consumption optical information processing sy...All-optical devices,which are utilized to process optical signals without electro-optical conversion,play an essential role in the next generation ultrafast,ultralow power-consumption optical information processing systems.To satisfy the performance requirement,nonlinear optical materials that are associated with fast response,high nonlinearity,broad wavelength operation,low optical loss,low fabrication cost,and integration compatibility with optical components are required.Graphene is a promising candidate,particularly considering its electrically or optically tunable optical properties,ultrafast large nonlinearity,and high integration compatibility with various nanostructures.Thus far,three all-optical modulation systems utilize graphene,namely free-space modulators,fiber-based modulators,and on-chip modulators.This paper aims to provide a broad view of state-of-the-art researches on the graphene-based all-optical modulation systems.The performances of different devices are reviewed and compared to present a comprehensive analysis and perspective of graphene-based all-optical modulation devices.展开更多
基金Supported by the Guangdong Special Support Talent Team Program(No.2019BT02H594)the National Natural Science Foundation of China(Nos.42174081,41804071,U2244221)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515011526)。
文摘The seafloor vector magnetometer is an effective tool for marine geomagnetic surveys and seafloor magnetotelluric(MT)detection.However,the noise,power consumption,cost,and volume characteristics of existing seafloor vector magnetometers are insufficient for practical use.Therefore,a low-noise,low-power-consumption seafloor vector magnetometer that can be used for data acquisition of deep-ocean geomagnetic vector components is developed and presented.A seafloor vector magnetometer mainly consists of a fluxgate sensor,data acquisition module,acoustic release module,glass sphere,frame,burn-wire release,and anchor.A new low-noise data acquisition module and a fluxgate sensor greatly reduce power consumption.Furthermore,compact size is achieved by integrating an acoustic telemetry module and replacing the acoustic release with an external burn-wire release.The new design and magnetometer characteristics reduce the volume of the instrument and the cost of hardware considerably,thereby improving the integrity and deployment efficiency of the equipment.Theoretically,it can operate for 90 days underwater at a maximum depth of 6000 m.The seafloor vector magnetometer was tested in the South China Sea and the Philippine Sea and obtained high-quality geomagnetic data.The deep-water environment facilitates magnetic field data measurements,and the magnetometer has an approximate noise level of 10 pT/rt(Hz)@1 Hz,a peak-to-peak value error of 0.2 nT,and approximate power consumption of 200 mW.The fluxgate sensor can measure the magnetic field in the lower frequency band and realize geomagnetic field measurements over prolonged periods.
文摘A study of wireless technologies for IoT applications in terms of power consumption has been presented in this paper. The study focuses on the importance of using low power wireless techniques and modules in IoT applications by introducing a comparative between different low power wireless communication techniques such as ZigBee, Low Power Wi-Fi, 6LowPAN, LPWA and their modules to conserve power and longing the life for the IoT network sensors. The approach of the study is in term of protocol used and the particular module that achieve that protocol. The candidate protocols are classified according to the range of connectivity between sensor nodes. For short ranges connectivity the candidate protocols are ZigBee, 6LoWPAN and low power Wi-Fi. For long connectivity the candidate is LoRaWAN protocol. The results of the study demonstrate that the choice of module for each protocol plays a vital role in battery life due to the difference of power consumption for each module/protocol. So, the evaluation of protocols with each other depends on the module used.
基金National Natural Science Foundation of China(No.61071087)Natural Science Foundation of Shandong Province(No.ZR2011FM018)
文摘According to the transit-time difference measurement method,we proposed a design scheme of ultrasonic heat meter based on TDC-GP21.The measurement unit TDC-GP21 mainly completes transit-time measurement and inlet,outlet temperature measurement functions.Control unit and data processing unit based on MSP430F4152 of TI corporation complete functions including peripherals control,data analysis,temperature compensation algorithm,flow pattern compensation algorithm and low power consumption control.The design meets the Town Construction Professional Standard CJ 128-2007,and furthermore,some performances can be improved.
文摘The miniaturization and endurance of wearable devices have been the research direction for a long time.With the development of nanotechnology and the emergence of microelectronics products,people have explored many new strategies that may be applied to wearable devices.In this overview,we will summarize the recent research of wearable devices in these two directions,and summarize some available related technologies.
基金supported by the National Natural Science Foundation of China(No.61471233)Shanghai Sailing Program(No.21YF1431400)。
文摘There is a great demand for high-performance hydrogen sulfide(H_(2)S)sensors with low operating temperatures.Ag/In_(2)O_(3)hexagonal tubes with different proportions were prepared by the calcination of Ag+-impregnated indium-organic frameworks(CPP-3(In)),and the developed sensors exhibit enhanced gas-sensing performance toward H_(2)S.Gas sensing measurements indicate that the response of Ag/In_(2)O_(3)(2.5 wt%)sensor to 5 ppm H_(2)S has the highest response(119),operated at 70℃.The Ag/In_(2)O_(3)(2.5 wt%)based sensor exhibits short response time(20 s),low detection limit(300 ppb),and good selectivity toward H_(2)S gas,which imply that the CPP-3(In)-derived Ag/In_(2)O_(3)hexagonal tube is a promising candidate to be constructed a low power-consumption H_(2)S sensor.
基金supported by the National Key Research and Development Program of China(Nos.2021YFB3602500 and 2021YFB3602502)。
文摘In an acousto-optic modulator,the electrode shape plays an important role in performance,since it affects the distribution of the acoustic field.The acousto-optic modulator based on the conventional rectangular electrode has the problems of low energy efficiency and small modulation bandwidth due to an imperfect acoustic field.In this paper,a new serrated periodic electrode has been proposed for using acousto-optic modulator transducers.The proposed electrode has the following advantages.By using serrated periodic electrodes to suppress the sidelobes,the collimation of the acoustic field in the direction perpendicular to the light incidence is improved.This makes the acousto-optic modulator have a stable diffraction efficiency fluctuation and high energy efficiency.In addition,the electrode has a large divergence angle in the direction of light incidence,so a large bandwidth can be obtained.The simulations and experiments demonstrate that the serrated periodic electrode has an increased bandwidth and high energy efficiency.
基金supported by the National Natural Science Foundation of China(Grant Nos.91950204 and 61975179)the National Key Research and Development Program of China(No.2019YFB2203002)Shanghai Sailing Program(No.19YF1435400).
文摘All-optical devices,which are utilized to process optical signals without electro-optical conversion,play an essential role in the next generation ultrafast,ultralow power-consumption optical information processing systems.To satisfy the performance requirement,nonlinear optical materials that are associated with fast response,high nonlinearity,broad wavelength operation,low optical loss,low fabrication cost,and integration compatibility with optical components are required.Graphene is a promising candidate,particularly considering its electrically or optically tunable optical properties,ultrafast large nonlinearity,and high integration compatibility with various nanostructures.Thus far,three all-optical modulation systems utilize graphene,namely free-space modulators,fiber-based modulators,and on-chip modulators.This paper aims to provide a broad view of state-of-the-art researches on the graphene-based all-optical modulation systems.The performances of different devices are reviewed and compared to present a comprehensive analysis and perspective of graphene-based all-optical modulation devices.
