期刊文献+
共找到13,189篇文章
< 1 2 250 >
每页显示 20 50 100
Treadmill exercise in combination with acousto-optic and olfactory stimulation improves cognitive function in APP/PS1 mice through the brain-derived neurotrophic factor-and Cygb-associated signaling pathways
1
作者 Biao Xiao Chaoyang Chu +6 位作者 Zhicheng Lin Tianyuan Fang Yuyu Zhou Chuxia Zhang Jianghui Shan Shiyu Chen Liping Li 《Neural Regeneration Research》 SCIE CAS 2025年第9期2706-2726,共21页
A reduction in adult neurogenesis is associated with behavioral abnormalities in patients with Alzheimer's disease.Consequently,enhancing adult neurogenesis represents a promising therapeutic approach for mitigati... A reduction in adult neurogenesis is associated with behavioral abnormalities in patients with Alzheimer's disease.Consequently,enhancing adult neurogenesis represents a promising therapeutic approach for mitigating disease symptoms and progression.Nonetheless,nonpharmacological interventions aimed at inducing adult neurogenesis are currently limited.Although individual non-pharmacological interventions,such as aerobic exercise,acousto-optic stimulation,and olfactory stimulation,have shown limited capacity to improve neurogenesis and cognitive function in patients with Alzheimer's disease,the therapeutic effect of a strategy that combines these interventions has not been fully explored.In this study,we observed an age-dependent decrease in adult neurogenesis and a concurrent increase in amyloid-beta accumulation in the hippocampus of amyloid precursor protein/presenilin 1 mice aged 2-8 months.Amyloid deposition became evident at 4 months,while neurogenesis declined by 6 months,further deteriorating as the disease progressed.However,following a 4-week multifactor stimulation protocol,which encompassed treadmill running(46 min/d,10 m/min,6 days per week),40 Hz acousto-optic stimulation(1 hour/day,6 days/week),and olfactory stimulation(1 hour/day,6 days/week),we found a significant increase in the number of newborn cells(5'-bromo-2'-deoxyuridine-positive cells),immature neurons(doublecortin-positive cells),newborn immature neurons(5'-bromo-2'-deoxyuridine-positive/doublecortin-positive cells),and newborn astrocytes(5'-bromo-2'-deoxyuridine-positive/glial fibrillary acidic protein-positive cells).Additionally,the amyloid-beta load in the hippocampus decreased.These findings suggest that multifactor stimulation can enhance adult hippocampal neurogenesis and mitigate amyloid-beta neuropathology in amyloid precursor protein/presenilin 1 mice.Furthermore,cognitive abilities were improved,and depressive symptoms were alleviated in amyloid precursor protein/presenilin 1 mice following multifactor stimulation,as evidenced by Morris water maze,novel object recognition,forced swimming test,and tail suspension test results.Notably,the efficacy of multifactor stimulation in consolidating immature neurons persisted for at least 2weeks after treatment cessation.At the molecular level,multifactor stimulation upregulated the expression of neuron-related proteins(NeuN,doublecortin,postsynaptic density protein-95,and synaptophysin),anti-apoptosis-related proteins(Bcl-2 and PARP),and an autophagyassociated protein(LC3B),while decreasing the expression of apoptosis-related proteins(BAX and caspase-9),in the hippocampus of amyloid precursor protein/presenilin 1 mice.These observations might be attributable to both the brain-derived neurotrophic factor-mediated signaling pathway and antioxidant pathways.Furthermore,serum metabolomics analysis indicated that multifactor stimulation regulated differentially expressed metabolites associated with cell apoptosis,oxidative damage,and cognition.Collectively,these findings suggest that multifactor stimulation is a novel non-invasive approach for the prevention and treatment of Alzheimer's disease. 展开更多
关键词 acousto-optic stimulation adult neurogenesis Alzheimer's disease amyloid precursor protein/presenilin 1 mice amyloid-beta deposition brain cell apoptosis cognitive impairment depression-like behavior involuntary treadmill exercise olfactory stimulation serum metabolites
下载PDF
Feature extraction and damage alarming using time series analysis 被引量:4
2
作者 刘毅 李爱群 +1 位作者 费庆国 丁幼亮 《Journal of Southeast University(English Edition)》 EI CAS 2007年第1期86-91,共6页
Aiming at the problem of on-line damage diagnosis in structural health monitoring (SHM), an algorithm of feature extraction and damage alarming based on auto-regressive moving-average (ARMA) time series analysis i... Aiming at the problem of on-line damage diagnosis in structural health monitoring (SHM), an algorithm of feature extraction and damage alarming based on auto-regressive moving-average (ARMA) time series analysis is presented. The monitoring data were first modeled as ARMA models, while a principalcomponent matrix derived from the AR coefficients of these models was utilized to establish the Mahalanobisdistance criterion functions. Then, a new damage-sensitive feature index DDSF is proposed. A hypothesis test involving the t-test method is further applied to obtain a decision of damage alarming as the mean value of DDSF had significantly changed after damage. The numerical results of a three-span-girder model shows that the defined index is sensitive to subtle structural damage, and the proposed algorithm can be applied to the on-line damage alarming in SHM. 展开更多
关键词 feature extraction damage alarming time series analysis structural health monitoring
下载PDF
Theoretical research on structural damage alarming of long-span bridges using wavelet packet analysis 被引量:5
3
作者 丁幼亮 李爱群 缪长青 《Journal of Southeast University(English Edition)》 EI CAS 2005年第4期459-462,共4页
The state equation and observation equation of the structural dynamic systems under various analysis scales are derived based on wavelet packet analysis. The time-frequency properties of structural dynamic response un... The state equation and observation equation of the structural dynamic systems under various analysis scales are derived based on wavelet packet analysis. The time-frequency properties of structural dynamic response under various scales are further formulated. The theoretical analysis results reveal that the wavelet packet energy spectrum (WPES) obtained from wavelet packet decomposition of structural dynamic response will detect the presence of structural damage. The sensitivity analysis of the WPES to structural damage and measurement noise is also performed. The transfer properties of the structural system matrix and the observation noise under various analysis scales are formulated, which verify the damage alarming reliability using the proposed WPES with preferable damage sensitivity and noise robusticity. 展开更多
关键词 structural damage alarming wavelet packet analysis wavelet packet energy spectrum long-span bridge
下载PDF
Controlling and synchronizing spatiotemporal chaos of the coupled Bragg acousto-optical bistable map system using nonlinear feedback 被引量:12
4
作者 岳立娟 沈柯 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第9期1760-1765,共6页
In this paper we present the control and synchronization of a coupled Bragg acousto-optic bistable map system using nonlinear feedback technology. This nonlinear feedback technology is useful to control a temporally c... In this paper we present the control and synchronization of a coupled Bragg acousto-optic bistable map system using nonlinear feedback technology. This nonlinear feedback technology is useful to control a temporally chaotic system as well as a spatiotemporally chaotic system. It can be extended to synchronize the spatiotemporal chaos. It can work in a wide range of the controlled and synchronized signals, so it can decrease the sensitivity down to a noise level. The synchronization can be obtained by the analysis of the largest conditional Lyapunov exponent spectrum, and easily implemented in practical systems just by adjusting the coupled strength without any pre-knowledge of the dynamic system required. 展开更多
关键词 synchronization and control spatiotemporal chaos nonlinear feedback acousto-optic bistable map system
下载PDF
Acousto-optic scanning spatial-switching multiphoton lithography 被引量:5
5
作者 Binzhang Jiao Fayu Chen +6 位作者 Yuncheng Liu Xuhao Fan Shaoqun Zeng Qi Dong Leimin Deng Hui Gao Wei Xiong 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2023年第3期597-606,共10页
Nano-3D printing has obtained widespread attention owing to its capacity to manufacture end-use components with nano-scale features in recent years.Multiphoton lithography(MPL)is one of the most promising 3D nanomanuf... Nano-3D printing has obtained widespread attention owing to its capacity to manufacture end-use components with nano-scale features in recent years.Multiphoton lithography(MPL)is one of the most promising 3D nanomanufacturing technologies,which has been widely used in manufacturing micro-optics,photonic crystals,microfluidics,meta-surface,and mechanical metamaterials.Despite of tremendous potential of MPL in laboratorial and industrial applications,simultaneous achievement of high throughput,high accuracy,high design freedom,and a broad range of material structuring capabilities remains a long-pending challenge.To address the issue,we propose an acousto-optic scanning with spatial-switching multispots(AOSS)method.Inertia-free acousto-optic scanning and nonlinear swept techniques have been developed for achieving ultrahigh-speed and aberration-free scanning.Moreover,a spatial optical switch concept has been implemented to significantly boost the lithography throughput while maintaining high resolution and high design freedom.An eight-foci AOSS system has demonstrated a record-high 3D printing rate of 7.6×10^(7)voxel s^(-1),which is nearly one order of magnitude higher than earlier scanning MPL,exhibiting its promise for future scalable 3D nanomanufacturing. 展开更多
关键词 3D nano-printing acousto-optic scanning aberration-free wavefront spatial-switching
下载PDF
An ECG Monitoring and Alarming System Based On Android Smart Phone 被引量:2
6
作者 Xiaoqiang Guo Xiaohui Duan +2 位作者 Hongqiao Gao Anpeng Huang Bingli Jiao 《Communications and Network》 2013年第3期584-589,共6页
ECG monitoring in daily life is an important means of treating heart disease. To make it easier for the medical to monitor the ECG of their patients outside the hospital, we designed and developed an ECG monitoring an... ECG monitoring in daily life is an important means of treating heart disease. To make it easier for the medical to monitor the ECG of their patients outside the hospital, we designed and developed an ECG monitoring and alarming system based on Android smart phone. In our system, an ECG device collects the ECG signal and transmits it to an Android phone. The Android phone detects alarms which come from the ECG devices. When alarms occur, Android phone will capture the ECG images and the details about the alarms, and sends them to the cloud Alarm Server (AS). Once received, AS push the messages to doctors’ phone, so the doctors could see the ECG images and alarm details on their mobile phone. In our system, high resolution ECG pictures are transmitted to doctors’ phone in a user-friendly way, which can help doctors keep track of their patient’s condition easily. 展开更多
关键词 ECG MONITORING System ANDROID SMART PHONE alarm
下载PDF
Damage alarming for bridge expansion joints using novelty detection technique based on long-term monitoring data 被引量:4
7
作者 缪长青 邓扬 +1 位作者 丁幼亮 李爱群 《Journal of Central South University》 SCIE EI CAS 2013年第1期226-235,共10页
Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for... Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for bridge expansion joints based on long-term monitoring data was developed. The effects of environmental factors on the expansion joint displacement were analyzed. Multiple linear regression models were obtained to describe the correlation between displacements and the dominant environmental factors. The damage alarming index was defined based on the multiple regression models. At last, the X-bar control chart was utilized to detect the abnormal change of the displacements. Analysis results reveal that temperature and traffic condition are the dominant environmental factors to influence the displacement. When the confidence level of X-bar control chart is set to be 0.003, the false-positive indications of damage can be avoided. The damage sensitivity analysis shows that the proper X-bar control chart can detect 0.1 cm damage-induced change of the expansion joint displacement. It is reasonably believed that the proposed technique is robust against false-positive indication of damage and suitable to alarm the possible future damage of the expansion joints. 展开更多
关键词 damage alarming expansion joint TEMPERATURE traffic condition control chart suspension bridge
下载PDF
A Modified Monte Carlo Model of Speckle Tracking of Shear Wave Induced by Acoustic Radiation Force for Acousto-Optic Elasticity Imaging 被引量:3
8
作者 李玉娇 黄伟骏 +3 位作者 马风超 王睿 陆明珠 万明习 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第11期54-57,共4页
A modified Monte Carlo model of speckle tracking of shear wave propagation in scattering media is proposed. The established Monte Carlo model mainly concerns the variations of optical electric field and speckle. The t... A modified Monte Carlo model of speckle tracking of shear wave propagation in scattering media is proposed. The established Monte Carlo model mainly concerns the variations of optical electric field and speckle. The two- dimensional intensity distribution and the time evolution of speckles in different probe locations are obtained. The fluctuation of speckle intensity tracks the acoustic-radiation-force shear wave propagation, and especially the reduction of speckle intensity implies attenuation of shear wave. Then, the shear wave velocity is estimated quantitatively on the basis of the time-to-peak algorithm and linear regression processing. The results reveal that a smaller sampling interval yields higher estimation precision and the shear wave velocity is estimated more efficiently by using speckle intensity difference than by using speckle contrast difference according to the estimation error. Hence, the shear wave velocity is estimated to be 2.25 m/s with relatively high accuracy for the estimation error reaches the minimum (0.071). 展开更多
关键词 of on IS for A Modified Monte Carlo Model of Speckle Tracking of Shear Wave Induced by Acoustic Radiation Force for acousto-optic Elasticity Imaging by in
下载PDF
Acousto-Optically Q-Switched Operation of Yb:CNGG Disordered Crystal Laser 被引量:2
9
作者 司维 马衍骏 +3 位作者 王丽莎 苑华磊 孔伟金 刘均海 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第12期28-31,共4页
We report the repetitively Q-switched laser operation of the Yb-doped calcium niobium gallium garnet disordered garnet crystal, achieved with an acousto-optic modulator in a compact plano-concave resonator that is end... We report the repetitively Q-switched laser operation of the Yb-doped calcium niobium gallium garnet disordered garnet crystal, achieved with an acousto-optic modulator in a compact plano-concave resonator that is endpumped by a 935-nm diode laser. An average output power of 1.96 W is produced at pulse repetition rate of50 k Hz at emission wavelengths around 1035 nm, with a slope efficiency of 16%. The highest pulse energy of 269 μJ is generated at pulse repetition rate of 1 k Hz, with pulse width 12.1 ns and peak power 20.53 kW. 展开更多
关键词 YB acousto-optically Q-Switched Operation of Yb:CNGG Disordered Crystal Laser
下载PDF
Damage alarming of long-span suspension bridge based on GPS-RTK monitoring 被引量:7
10
作者 缪长青 王蔓 +2 位作者 田洪金 冯兆祥 陈策 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2800-2808,共9页
Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.Firs... Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.First,the effects of temperature on the main girder spatial position coordinates were analyzed from the transverse,longitudinal and vertical directions of bridge,and the correlation regression models were built between temperature and the position coordinates of main girder in the longitudinal and vertical directions;then the alarming indices of coordinate residuals were conducted,and the mean-value control chart was applied to making statistical pattern identification for abnormal changes of girder dynamic coordinates;and finally,the structural damage alarming method of main girder was established.Analysis results show that temperature has remarkable correlation with position coordinates in the longitudinal and vertical directions of bridge,and has weak correlation with the transverse coordinates.The 3%abnormal change of the longitudinal coordinates and 5%abnormal change of the vertical ones caused by structural damage are respectively identified by the mean-value control chart method based on GPS dynamic monitoring data and hence the structural abnormalities state identification and damage alarming for main girder of long-span suspension bridge can be realized in multiple directions. 展开更多
关键词 long-span suspension bridge damage alarming mean-value control chart GPS displacement temperature correlation
下载PDF
High-Resolution Broadband Millimeter-Wave Astrophysical Spectrometer with Triple Product Acousto-Optical Processor 被引量:1
11
作者 Miguel Chavez Dagostino Alexandre S. Shcherbakov +1 位作者 Adan Omar Arellanes Vahram Chavushyan 《International Journal of Astronomy and Astrophysics》 2013年第4期421-430,共10页
An advanced conceptual design of a high-bit-rate triple product acousto-optical processor is presented that can be applied in a number of astrophysical problems. We briefly describe the Large Millimeter Telescope as o... An advanced conceptual design of a high-bit-rate triple product acousto-optical processor is presented that can be applied in a number of astrophysical problems. We briefly describe the Large Millimeter Telescope as one of the potential observational infrastructures where the acousto-optical spectrometer can be successfully used. A summary on the study of molecular gas in relatively old (age > 10 Myr) disks around main sequence stars is provided. We have identified this as one of the science cases in which the proposed processor can have a big impact. Then we put forward triple product acousto-optical processor is able to realize algorithm of the space-and-time integrating, which is desirable for a wideband spectrum analysis of radio-wave signals with an improved resolution providing the resolution power of about 105 - 106. It includes 1D-acousto-optic cells as the input devices for a 2D-optical data processing. The importance of this algorithm is based on exploiting the chirp Z-transform technique providing a 2D-Fourier transform of the input signals. The system produces the folded spectrum, accumulating advantages of both space and time integrating. Its frequency bandwidth is practically equal to the bandwidth of transducers inherent in acousto-optical cells. Then, similar processor is able to provide really high frequency resolution, which is practically equal to the reciprocal of the CCD-matrix photo-detector integration time. Here, the current state of developing the triple product acousto-optical processor in frames of the astrophysical instrumentation is shortly discussed. 展开更多
关键词 Astrophysical Instrumentation Radio-Astronomy MILLIMETER-WAVE SPECTROMETER Space-and-Time Integrating acousto-optical Devices Optical Processing System
下载PDF
Acousto-optic Devices: Theory and Applications
12
作者 SHIJianjun SHIYongji 《Semiconductor Photonics and Technology》 CAS 1998年第3期135-145,共11页
The basics and applications of acousto-optic devices are described.The applications include acousto-optic spectrum analyzer,acousto-optic deflector,acousto-optic processors and acousto-optic digital matrix computer.
关键词 acousto-optic Deflector acousto-optic Digital Matrix Computer acousto-optic Modulator acousto-optic Processor acousto-optic Spectrum Analyzer
下载PDF
High-Power Continuous-Wave and Acousto-Optical Q-Switched Ho:(Sc_(0.5)Y_(0.5))_2SiO_5 Laser Pumped by Laser Diode
13
作者 Xiao-Ming Duan Guang-Peng Chen +2 位作者 Ying-Jie Shen Li-He Zheng Liang-Bi Su 《Chinese Physics Letters》 SCIE CAS CSCD 2019年第6期29-32,共4页
We experimentally investigate the continuous-wave(cw)and acousto-optical(AO)Q-switched performance of a diode-pumped Ho:(Sc_(0.5)Y_(0.5))_2SiO_5(Ho:SYSO)laser.A fiber-coupled laser diode at 1.91m is employed as the pu... We experimentally investigate the continuous-wave(cw)and acousto-optical(AO)Q-switched performance of a diode-pumped Ho:(Sc_(0.5)Y_(0.5))_2SiO_5(Ho:SYSO)laser.A fiber-coupled laser diode at 1.91m is employed as the pump source.The cw Ho:SYSO laser produces 13.0 W output power at 2097.9 nm and 56.0%slope efficiency with respect to the absorbed pump power.In the AO Q-switched regime,at a pulse repetition frequency of 5 kHz,the Ho:SYSO laser yields 2.1 mJ pulse energy and 21 ns pulse width,resulting in a calculated peak power of 100 k W.In addition,at the maximum output level,the beam quality factor of the Q-switched Ho:SYSO laser is measured to be about 1.6. 展开更多
关键词 HIGH-POWER CONTINUOUS-WAVE acousto-optical LASER Diode
下载PDF
Solution to reduce call drop based on alarming information in WCDMA networks
14
作者 范伶 张睿 韩慧莲 《Journal of Measurement Science and Instrumentation》 CAS 2012年第1期85-89,共5页
Deep analysis of call detail log of the alarming information indicates that reasons except user equipment(UE)issue are usually ignored.To effectively reduce call drop rate in wideband code division multiple access(WCD... Deep analysis of call detail log of the alarming information indicates that reasons except user equipment(UE)issue are usually ignored.To effectively reduce call drop rate in wideband code division multiple access(WCDMA)mobile communication system,a novel method is presented.First,the reliable trace information is extracted to observe the distribution of all the exceptions from radio network controller(RNC)daily report.Then,the antenna angle of generalized clustering network in 024 base station’s c sector(GCN024C)for environmental test(ET)which is obtained from the radio frequency(RF)engineer is manually changed from 4° to 6°.Experimental results show that the proposed method can guarantee the key performance indicators(KPI)of WCDMA and have obvious effect on reducing call drop rate. 展开更多
关键词 alarming information call drop rate antenna angle radio frequency
下载PDF
High-power xenon lamp-pumped Er:YAP pulse laser operated in free-running and acousto-optical Q-switching modes
15
作者 权聪 孙敦陆 +7 位作者 张会丽 罗建乔 韩志远 乔阳 陈玙威 王镇涛 程毛杰 张庆礼 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期472-476,共5页
We demonstrate a high-energy and high-power pulse laser on a xenon lamp-pumped Er:YAP crystal. The laser performance and thermal focal lengths under different working frequencies are discussed. The results show that t... We demonstrate a high-energy and high-power pulse laser on a xenon lamp-pumped Er:YAP crystal. The laser performance and thermal focal lengths under different working frequencies are discussed. The results show that the thermal lens effect is gradually aggravated with the increase of working frequencies, and even working at 100 Hz, a single pulse energy of 234 m J can be achieved. A maximum average power of 41.5 W is achieved with a working frequency of 20 Hz and slope efficiency of 2.82%. This output power is much higher than other xenon lamp-pumped erbium laser devices.A Q-switched laser is demonstrated by using the TeO2crystal, the maximum output energies of 11.5 m J and 3.5 m J are obtained at 50 and 100 Hz, the corresponding peak powers are 93.4 k W and 17.2 kW, respectively.The laser wavelengths and beam quality factors are also characterized in the free-running and Q-switched modes. A higher pulse energy and peak power laser could be achieved further by improving the damage threshold of TeO2acousto-optical Q-switching. All the experimental results illustrate that the xenon lamp-pumped Er:YAP laser is a promising candidate for high-power and high-frequency mid-infrared laser devices. 展开更多
关键词 Er:YAP crystal xenon lamp-pumped mid-infrared laser acousto-optical Q-switching
下载PDF
Digital Acousto-optic Matrix Computer
16
作者 SHI Yong-ji, WU Xin,ZOU Hong-wen ((Luoyang Technology College, Louyang 471003,CHN) 《Semiconductor Photonics and Technology》 CAS 1999年第2期74-81,共8页
Acousto-optic system for performing basic operations of vector-matrix multiplication with digital(16-bit)accuracy are described.The system comprised of two multi-transducer Bragg cells that can perform at least 1×... Acousto-optic system for performing basic operations of vector-matrix multiplication with digital(16-bit)accuracy are described.The system comprised of two multi-transducer Bragg cells that can perform at least 1×10 8 operation/s of basic vector-matrix multiplication with digital (16-bit ) accuracy and which is simple and compact. 展开更多
关键词 acousto-optic Device acousto-optic Processor Analog Convolution Inner Product Multi-transducer Bragg Cell Vector-matrix Multiplication CLC number:TP302.1 Document code:A
下载PDF
THE DATA PROCESSING TECHNIQUE FOR INTEGRATED-OPTICS ACOUSTO-OPTIC RF SPECTRUM ANALYZER
17
作者 金圣经 朴燕 王瑞光 《Journal of Electronics(China)》 1993年第3期267-272,共6页
The system of Integrated-Optics Acousto-Optic RF Spectrum Analyzer (IOAOSA)consists of a laser diode, an Acousto-Optic (A-O) modulator, geodesic lenses and CCD detectorarray. The optical signal projected on the CCD ar... The system of Integrated-Optics Acousto-Optic RF Spectrum Analyzer (IOAOSA)consists of a laser diode, an Acousto-Optic (A-O) modulator, geodesic lenses and CCD detectorarray. The optical signal projected on the CCD array is converted into electrical signal andprocessed by the signal processing center which consists of a TMS 32010 system and an IBM-PC.The TMS 32010 with very high speed is used in a microcomputer system. A cycle sample methodis adopted to collect the data of the CCD video signal, sampling one per 40-point. After theprocessing, the frequency bandwidth, the resolution and the dynamic range of the system aremeasured to be 100 MHz, 8 MHz and 20 dB, respectively. 展开更多
关键词 SIGNAL processing acousto-optic RF SPECTRUM analyzer(AOSA) CCD DETECTOR array
下载PDF
Designing of Acousto-optic Spectrum Analyzer
18
作者 WANGDan-zhi SHAODing-rong LIShu-jian 《Semiconductor Photonics and Technology》 CAS 2004年第4期237-239,共3页
The structure of the acousto-optic spectrum analyzer was investigated including the RF amplifying circuit, the optical structures and the postprocessing circuit, and the design idea of the module was applied to design... The structure of the acousto-optic spectrum analyzer was investigated including the RF amplifying circuit, the optical structures and the postprocessing circuit, and the design idea of the module was applied to design the spectrum analyzer. The modularization spectrum analyzer takes on the performance stabilization and higher reliability, and according to different demands, the different modules can be used. The spectrum analyzer had such performances as the detecting frequency precision of 1 MHz, the detecting frequency error of 0.58 MHz, detecting responsivity of 90 dBm and bandwidth of 50 MHz. 展开更多
关键词 acousto-optic signal processing Spectrum analyzer Structures designing
下载PDF
Mathematical Description of Acousto-Optic Tunable Filter Orthogonal Polarizing Method
19
作者 徐可欣 文慧智 +2 位作者 张浩 范国芳 杨吉生 《Transactions of Tianjin University》 EI CAS 2005年第4期295-298,共4页
The transfer function of the optical splitting system of the acousto-optic tunable filter (AOTF) is deduced to be a reference to optical design. The characteristic matrix ( transfer function) of AOTF is used to de... The transfer function of the optical splitting system of the acousto-optic tunable filter (AOTF) is deduced to be a reference to optical design. The characteristic matrix ( transfer function) of AOTF is used to describe quantitatively the characters of polarization elements in the orthogonal polarizing system. According to the characteristic matrix, the included angle of polarizer's transmission direction and polarization analyzer's transmission direction should be 90°. As a result the signal to noise ratio increased about 20 times though the light intensity was reduced to 54.3%,because both the transmittances of polarizer and polarization analyzer are 0. 74, which is an intrinsic character. The orthogonal polarizing method is an effective method to get rid of the influence of zero order light and improve the spectrum resolution and signal-to-noise ratio. 展开更多
关键词 acousto-optic tunable filter: characteristic matrix optical splitting system orthogonal polarizing method
下载PDF
Development of miniaturized SAF-LIBS with high repetition rate acousto-optic gating for quantitative analysis
20
作者 陈斐 侯佳佳 +10 位作者 王刚 赵洋 李佳轩 王树青 张雷 张婉飞 马晓飞 刘珍荣 罗学彬 尹王保 贾锁堂 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第1期157-164,共8页
The self-absorption effect in laser-induced breakdown spectroscopy(LIBS)reduces the accuracy of quantitative measurement results.The self-absorption-free LIBS(SAF-LIBS)has been proved to directly capture the optically... The self-absorption effect in laser-induced breakdown spectroscopy(LIBS)reduces the accuracy of quantitative measurement results.The self-absorption-free LIBS(SAF-LIBS)has been proved to directly capture the optically thin plasma spectra by setting an appropriate exposure time.In this work,a novel SAF-LIBS technique with high repetition rate acousto-optic gating is developed,in which an acousto-optic modulator is used as the shutter to diffract the optically thin fluorescence,and a high repetition rate laser is used to produce quasi-continuous plasmas to enhance the integral spectral intensity,so that the CCD spectrometer can replace an intensified CCD(ICCD)and echelle spectrometer in SAF-LIBS.Experimental results show that the average absolute prediction error of aluminum is reduced to 0.18%,which is equivalent to that of traditional SAF-LIBS.This technique not only effectively shields continuous background radiation and broadened spectral lines in optically thick plasma,but also has advantages of miniaturization,low cost,convenience and reliability. 展开更多
关键词 self-absorption-free LIBS(SAF-LIBS) self-absorption effect optically thin plasma high repetition rate laser acousto-optic gating
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部