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Absorption Line Profile Recovery Based on TDLS and MEMS Micro-Mirror for Photoacoustic Gas Sensing
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作者 LI Li Norhana Arsad +3 位作者 George Stewart Deepak Uttamchandani Brian Culshaw WANG Yi-ding 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2011年第7期1814-1818,共5页
A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirr... A novel and efficient absorption line recovery technique is presented.A micro-electromechanical systems(MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection.Tunable diode laser spectroscopy(TDLS) and photoacoustic spectroscopy(PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile.The target gas is 0.01% acetylene(C2H2) in a nitrogen host gas.The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp,and an erbium-doped fibre amplifier(EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio(SNR).A SNR of about 35 is obtained with 100 mW laser power from the EDFA.Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile. 展开更多
关键词 micro-electro-mechanical-systems(MEMS) Laser intensity modulation Absorption line profile recovery Tunable diode laser spectroscopy Photo-acoustic gas sensing
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Particle Filter Data Fusion Enhancements for MEMS-IMU/GPS 被引量:2
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作者 Yafei Ren Xizhen Ke 《Intelligent Information Management》 2010年第7期417-421,共5页
This research aims at enhancing the accuracy of navigation systems by integrating GPS and Mi-cro-Electro-Mechanical-System (MEMS) based inertial measurement units (IMU). Because of the conditions re-quired by the larg... This research aims at enhancing the accuracy of navigation systems by integrating GPS and Mi-cro-Electro-Mechanical-System (MEMS) based inertial measurement units (IMU). Because of the conditions re-quired by the large number of restrictions on empirical data, a conventional Extended Kalman Filtering (EKF) is limited to apply in navigation systems by integrating MEMS-IMU/GPS. In response to non-linear non-Gaussian dynamic models of the inertial sensors, the methods rely on a particle cloud representation of the filtering distribution which evolves through time using importance sampling and resampling ideas. Then Particle Filtering (PF) can be used to data fusion of the inertial information and real-time updates from the GPS location and speed of information accurately. The experiments show that PF as opposed to EKF is more effective in raising MEMS-IMU/GPS navigation system’s data integration accuracy. 展开更多
关键词 micro-electro-mechanical-system Particle Filter Data Fusion Extended KALMAN FILTERING
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Capacitance Sensing and Software-Realized Lock-in Amplifier for the Electromagnetically Levitated Micro Gyroscope 被引量:1
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作者 黄晓刚 陈文元 +2 位作者 刘武 张卫平 吴校生 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第2期250-256,262,共8页
In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock... In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference.The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle.The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface.In the implementation of digital lock-in amplifier,a new routine which warranted the exactly matching of the reference phase to signal phase was proposed.The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal.The non linearity of the turn angle output is 2.3% and the minimum resolution of turn angle is 0.04 degrees.The application of the software demodulation in the signal detection of micro-electro-mechanical-system(MEMS)device is a new attempt,and it shows the prospective for a high-performance application. 展开更多
关键词 micro gyroscope capacitance sensing inertial sensor digital lock-in amplifier micro-electro-mechanical-system sensor
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Small MEMS smart antenna for software radio fuze
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作者 韩琦 徐立新 丛琳 《Journal of Beijing Institute of Technology》 EI CAS 2016年第2期159-163,共5页
The signal transceiver of the software radio fuze depends on the front-end radio frequency( RF) antenna. RF micro-electro-mechanical-system( MEMS) smart antennas have the capability of flexible beam rapid scanning... The signal transceiver of the software radio fuze depends on the front-end radio frequency( RF) antenna. RF micro-electro-mechanical-system( MEMS) smart antennas have the capability of flexible beam rapid scanning,multi-beam forming and so on,which can improve the ability of detecting,sensing and tracking multiple targets of the fuze. The small RF MEMS smart antenna consists of a 2 × 2 aperture coupled antenna array and six 1-bit MEMS phase shifters. Simulated results demonstrate that the antenna can complete beam steering angles of ± 30° in both X and Y plane at 17. 3 GHz. All components can be fabricated and monolithically integrated with MEMS technology which causes the system low cost and small volume. The RF MEMS smart antenna presents a good and important prospect for the development of the software radio fuze antenna. 展开更多
关键词 software radio fuze micro-electro-mechanical-system (MEMS) antenna smart anten-na monolithically-integrated
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A shoe-box-sized 3D laser nanoprinter based on two-step absorption
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作者 Tobias Messer Michael Hippe +1 位作者 Jingya(Lilyn)Gao Martin Wegener 《Light(Advanced Manufacturing)》 2024年第2期115-122,共8页
State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers,leading to fairly large and ex... State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers,leading to fairly large and expensive instruments.Lately,we have introduced photoresists based on two-step absorption instead of two-photon absorption,allowing for the use of small and inexpensive continuous-wave 405 nm wavelength GaN semiconductor laser diodes with light-output powers below 1 mW.Here,using the identical photoresist system and similar laser diodes,we report on the design,construction,and characterization of a 3D laser nanoprinter that fits into a shoe box.This shoe box contains all optical components,namely the mounted laser,the collimation-and beam-shaping optics,a miniature MEMS xy-scanner,a tube lens,the focusing microscope objective lens(NA=1.4,100×magnification),a piezo slip-stick z-stage,the sample holder,a camera monitoring system,LED sample illumination,as well as the miniaturized control electronics employing a microcontroller.We present a gallery of example 3D structures printed with this instrument.We achieve about 100 nm lateral spatial resolution and focus scan speeds of about 1 mm/s.Potentially,our shoe-box-sized system can be made orders of magnitude less expensive than today’s commercial systems. 展开更多
关键词 Two-step absorption Direct laser writing 3D laser nanoprinters micro-electro-mechanical-systems scanner 3D nanostructures
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