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Fault diagnosis method of link control system for gravitational wave detection
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作者 GAO Ai XU Shengnan +2 位作者 ZHAO Zichen SHANG Haibin XU Rui 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期922-931,共10页
To maintain the stability of the inter-satellite link for gravitational wave detection,an intelligent learning monitoring and fast warning method of the inter-satellite link control system failure is proposed.Differen... To maintain the stability of the inter-satellite link for gravitational wave detection,an intelligent learning monitoring and fast warning method of the inter-satellite link control system failure is proposed.Different from the traditional fault diagnosis optimization algorithms,the fault intelligent learning method pro-posed in this paper is able to quickly identify the faults of inter-satellite link control system despite the existence of strong cou-pling nonlinearity.By constructing a two-layer learning network,the method enables efficient joint diagnosis of fault areas and fault parameters.The simulation results show that the average identification time of the system fault area and fault parameters is 0.27 s,and the fault diagnosis efficiency is improved by 99.8%compared with the traditional algorithm. 展开更多
关键词 large scale multi-satellite formation gravitational wave detection laser link monitoring fault diagnosis deep learning
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Rapid Detection of Accelerants in Fire Debris Using a Field Portable Mid-Infrared Quantum Cascade Laser Based Analyzer
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作者 Hao Huang Yongfeng Zhang +6 位作者 Fuqiang Dai Xiaobo Yan Altayeb Hamdalnile Liyun Wu Tingting Zhang Haowen Li Frank Inscore 《Open Journal of Applied Sciences》 CAS 2023年第5期746-757,共12页
Arson presents a challenging crime scene for fire investigators worldwide. Key to the investigation of suspected arson cases is the analysis of fire debris for the presence of accelerants or ignitable liquids. This st... Arson presents a challenging crime scene for fire investigators worldwide. Key to the investigation of suspected arson cases is the analysis of fire debris for the presence of accelerants or ignitable liquids. This study has investigated the application and method development of vapor phase mid-Infrared (mid-IR) spectroscopy using a field portable quantum cascade laser (QCL) based system for the detection and identification of accelerant residues such as gasoline, diesel, and ethanol in fire debris. A searchable spectral library of various ignitable fluids and fuel components measured in the vapor phase was constructed that allowed for real-time identification of accelerants present in samples using software developed in-house. Measurement of vapors collected from paper material that had been doused with an accelerant followed by controlled burning and then extinguished with water showed that positive identification could be achieved for gasoline, diesel, and ethanol. This vapor phase mid-IR QCL method is rapid, easy to use, and has the sensitivity and discrimination capability that make it well suited for non-destructive crime scene sample analysis. Sampling and measurement can be performed in minutes with this 7.5 kg instrument. This vibrational spectroscopic method required no time-consuming sample pretreatment or complicated solvent extraction procedure. The results of this initial feasibility study demonstrate that this portable fire debris analyzer would greatly benefit arson investigators performing analysis on-site. 展开更多
关键词 Quantum Cascade laser (QCL) Mid-Infrared Spectroscopy Fire Debris Analysis Gasoline Vapor detection Ignitable Liquids
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Application of Laser Speckle Technology on the Detection of Agricultural Products
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作者 毕昆 王成 《Agricultural Science & Technology》 CAS 2011年第9期1376-1380,1384,共6页
[Objective] The research aimed at investigating the application of laser speckle technology in agricultural products detection.[Method] This article described the basic principle of the laser speckle technology,provid... [Objective] The research aimed at investigating the application of laser speckle technology in agricultural products detection.[Method] This article described the basic principle of the laser speckle technology,provided a review of application development of the laser speckle technology in agricultural products detection,analyzed the problems in agriculture products detection using laser speckle technology and described the prospects of laser speckle technology in agricultural products detection.[Result] The laser speckle technology is a non-destructive detection technology for quality determination of agricultural products,which can be used to classify the agricultural products reasonably according to the quality of agricultural products.[Conclusion] The article provided reference and consult for laser speckle detection technology research. 展开更多
关键词 laser speckle detection of agricultural products Image processing Nondestructive detection
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Influence of laser intensity in second-harmonic detection with tunable diode laser multi-pass absorption spectroscopy 被引量:9
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作者 阚瑞峰 董凤忠 +5 位作者 张玉钧 刘建国 刘诚 王敏 高山虎 陈军 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第9期1904-1909,共6页
Tunable diode laser absorption spectroscopy (TDLAS) has been widely employed in atmospheric trace gases detection. The ratio of the second-harmonic signal to the intensity of laser beam incident to the multi-pass ce... Tunable diode laser absorption spectroscopy (TDLAS) has been widely employed in atmospheric trace gases detection. The ratio of the second-harmonic signal to the intensity of laser beam incident to the multi-pass cell is proved to be proportional to the product of the path length and the gas concentration under any condition. A new calibration method based on this relation in TDLAS system for the measurement of trace gas concentration is proposed for the first time. The detection limit and the sensitivity of the system are below 110 and 31ppbv (parts-per-billion in volume), respectively. 展开更多
关键词 tunable diode laser absorption spectroscopy multi-pass cell harmonic detection wavelength modulation
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Damage Detection and Material Property Reconstruction of Composite Laminates Using Laser Ultrasonic Technique 被引量:4
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作者 QIU Jinhao TAO Chongcong +2 位作者 JI Hongli ZHANG Chao ZHAO Jinling 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2019年第1期1-16,共16页
Laser ultrasonic technique has received increasing attentions in the past decade due to its contactless nature and a wide range of applications have been reported. In this review,applications of laser ultrasonic techn... Laser ultrasonic technique has received increasing attentions in the past decade due to its contactless nature and a wide range of applications have been reported. In this review,applications of laser ultrasonic technique developed at Nanjing University of Aeronautics and Astronautics(NUAA)as well as elsewhere for non-destructive testing in composite laminates are presented. The principles of generating and detecting in a laser ultrasonic system are introduced,three different system configurations are also introduced with each configuration's advantages and disadvantages explained. More importantly,two major applications developed at NUAA for composite laminates are presented including damage detection,stiffness reconstruction and fatigue life prediction. Both applications are realized by a fixed-point PZT sensor and scanning pulse laser based on the linear reciprocal theorem. Analytical method and numerical models are employed and developed to realize the functionalities. 展开更多
关键词 laser ULTRASONIC COMPOSITE LAMINATES DAMAGE detection STIFFNESS RECONSTRUCTION
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Heavy Metal Detection in Soils by Laser Induced Breakdown Spectroscopy Using Hemispherical Spatial Confinement 被引量:6
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作者 孟德硕 赵南京 +5 位作者 马明俊 王寅 胡丽 余洋 方丽 刘文清 《Plasma Science and Technology》 SCIE EI CAS CSCD 2015年第8期632-637,共6页
Spatial confinement has great potential for Laser Induced Breakdown Spectroscopy (LIBS) instruments after it has been proven that it has the ability to enhance the LIBS signal strength and repeatability. In order to... Spatial confinement has great potential for Laser Induced Breakdown Spectroscopy (LIBS) instruments after it has been proven that it has the ability to enhance the LIBS signal strength and repeatability. In order to achieve in-situ measurement of heavy metals in farmland soils by LIBS, a hemispherical spatial confinement device is designed and used to collect plasma spectra, in which the optical fibers directly collect the breakdown spectroscopy of the soil samples. This device could effectively increase the stability of the spectrum intensity of soil. It also has other advantages, such as ease of installation, and its small and compact size. The relationship between the spectrum intensity and the laser pulse energy is studied for this device. It is found that the breakdown threshold is 160 cm-2, and when the laser fluence increases to 250 J/cm2, the spectrum intensity reaches its maximum. Four different kinds of laser pulse energy were set up and in each case the limits of detection of Cd, Cu, Ni, Pb and Zn were calculated. The results show that when the laser pulse fluence was 2.12 GW/cm2, we obtained the smallest limits of detection of these heavy metals, which are all under 10 mg/kg. This device can satisfy the needs of heavy metal in-situ detection, and in the next step it will be integrated into a portable LIBS instrument. 展开更多
关键词 laser induced breakdown spectroscopy hemispherical spatial confinement laser fiuence limit of detection
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Photoelectric detection technology of laser seeker signals 被引量:4
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作者 ZHU Likun JIA Fangxiu +1 位作者 JIANG Xiaodong LI Xinglong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第6期1064-1073,共10页
The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, t... The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals. 展开更多
关键词 laser seeker rolling angle error of position signal-to noise ratio(SNR) photoelectric detection.
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Acoustic wave detection of laser shock peening 被引量:5
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作者 Jiajun Wu Jibin Zhao +3 位作者 Hongchao Qiao Xuejun Liu Yinuo Zhang Taiyou Hu 《Opto-Electronic Advances》 2018年第9期11-15,共5页
In order to overcome the existing disadvantages of offline laser shock peening detection methods, an online detection method based on acoustic wave signals energy is provided. During the laser shock peening, an acoust... In order to overcome the existing disadvantages of offline laser shock peening detection methods, an online detection method based on acoustic wave signals energy is provided. During the laser shock peening, an acoustic emission sen- sor at a defined position is used to collect the acoustic wave signals that propagate in the air. The acoustic wave signal is sampled, stored, digitally filtered and analyzed by the online laser shock peening detection system. Then the system gets the acoustic wave signal energy to measure the quality of the laser shock peening by establishing the correspondence between the acoustic wave signal energy and the laser pulse energy. The surface residual stresses of the samples are measured by X-ray stress analysis instrument to verify the reliability. The results show that both the surface residual stress and acoustic wave signal energy are increased with the laser pulse energy, and their growth trends are consistent. Finally, the empirical formula between the surface residual stress and the acoustic wave signal energy is established by the cubic equation fitting, which will provide a theoretical basis for the real-time online detection of laser shock peening. 展开更多
关键词 laser shock PEENING ACOUSTIC WAVE laser pulse ENERGY surface residual stress ACOUSTIC WAVE signal ENERGY online detection
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Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate 被引量:5
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作者 Jyun-Yi Wu Chia-Hsin Chen +3 位作者 Li-Yin Yeh Ming-Long Yeh Chun-Chan Ting Yan-Hsiung Wang 《International Journal of Oral Science》 SCIE CAS CSCD 2013年第2期85-91,共7页
Retaining or improving periodontal ligament (PDL) function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation (LPLI) on the... Retaining or improving periodontal ligament (PDL) function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation (LPLI) on the proliferation and osteogenic differentiation of human PDL (hPDL) cells. Cultured hPDL cel Is were irradiated (660 nm) daily with doses of O, 1, 2 or 4 J .cm-2. Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase (ALP) activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR). Our data showed that LPLI at a dose of 2 J.cm-2 significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J.cm-2 showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate (cAMP) is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration. 展开更多
关键词 cell proliferation cyclic adenosine monophosphate human periodontal ligament cells low-power laser irradiation osteogenic differentiation
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Underwater four-quadrant dual-beam circumferential scanning laser fuze using nonlinear adaptive backscatter filter based on pauseable SAF-LMS algorithm 被引量:1
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作者 Guangbo Xu Bingting Zha +2 位作者 Hailu Yuan Zhen Zheng He Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第7期1-13,共13页
The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser fuzes.To overcome this issue,we propose a four-quadrant ... The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser fuzes.To overcome this issue,we propose a four-quadrant dual-beam circumferential scanning laser fuze to distinguish various interference signals and provide more real-time data for the backscatter filtering algorithm.This enhances the algorithm loading capability of the fuze.In order to address the problem of insufficient filtering capacity in existing linear backscatter filtering algorithms,we develop a nonlinear backscattering adaptive filter based on the spline adaptive filter least mean square(SAF-LMS)algorithm.We also designed an algorithm pause module to retain the original trend of the target echo peak,improving the time discrimination accuracy and anti-interference capability of the fuze.Finally,experiments are conducted with varying signal-to-noise ratios of the original underwater target echo signals.The experimental results show that the average signal-to-noise ratio before and after filtering can be improved by more than31 d B,with an increase of up to 76%in extreme detection distance. 展开更多
关键词 laser fuze Underwater laser detection Backscatter adaptive filter Spline least mean square algorithm Nonlinear filtering algorithm
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Transplantation of low-power laser-irradiated olfactory ensheathing cells to promote repair of spinal cord injury in rats 被引量:3
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作者 Haoxian Chen Xinfeng Zheng +3 位作者 Weibin Sheng Qin Wei Tao Jiang Gele Jin 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第3期171-177,共7页
BACKGROUND: Previous studies have demonstrated that low-power laser (LPL) irradiation can promote the regeneration of peripheral nerves and central nerves, as well as influence cellular proliferation. Therefore, it... BACKGROUND: Previous studies have demonstrated that low-power laser (LPL) irradiation can promote the regeneration of peripheral nerves and central nerves, as well as influence cellular proliferation. Therefore, it is thought to be a potential treatment for spinal cord injury. OBJECTIVE: Utilizing histological observations and behavioral evaluations, the aim of this study was to investigate the influence of transplanted olfactory ensheathing cells (OECs), irradiated by LPL, on functional repair of rats following transversal spinal cord injury. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the animal experimental center in the First Affiliated Hospital of Xinjiang Medical University between January 2007 and February 2008. MATERIALS: A total of 52 Sprague Dawley rats were included in this experiment. Twelve rats were used to harvest OECs, some of which were irradiated by LPL on days 3, 5, and 7 in culture. The remaining 40 rats were used to establish T12 complete spinal cord transection injury. DMEM/F12 medium was purchased from Sigma, USA, Fluorogold was provided by Chemicon, USA, and the LY/JG650-D500-16 low-power laser was produced by Xi'an Lingyue Electromechanical Science And Technology Co., Ltd., China. METHODS: The successful rat models were randomly divided into three groups: OEC transplantation, LPL-irradiated OEC transplantation, and control. These animals were microinjected with OEC suspension, LPL-irradiated OEC suspension, and DMEM/F12 medium (10μL) respectively 4 weeks after spinal cord was completely transected at the T12 level. MAIN OUTCOME MEASURES: Spinal cord injury was observed using hematoxylin-eosin staining Expression of nerve growth factor receptor p75 and glial fibrillary acidic protein were determined using immunohistochemical staining. Regeneration of spinal nerve fibers in rats was assayed by Fluorogold retrograde labeling method. Basso, Beattie and Bresnahan (BBB) scores were used to evaluate motor functions of rat lower limbs. RESULTS: Structural disturbances were observed following spinal cord injury in each group, and a large amount of scar tissue covered the broken ends, accompanied by porosis and inflammatory cell infiltration. Following OEC transplantation, the distal end connected to the proximal end. nerve growth factor receptor p75 and glial fibrillary acidic protein immunohistochemistry revealed positive OECs in the cephalad and caudal area of rats that received LPL-irradiated OEC transplantation. In the OECs group, only glial fibrillary acidic protein staining was observed. No staining was found in the control group. Neural fibers labeled with Fluorogold extended across the lesion area and into the cephalad and caudal area in the OECs and LPL-irradiated OECs groups, but were not present in the control group. BBB scores revealed statistically significant differences among the three groups (P 〈 0.05): OECs irradiated by LPL group 〉 OECs group 〉 control group. CONCLUSION: Transplantation of OECs and LPL-irradiated OECs promoted functional repair in the injured spinal cord of rats, although LPL-irradiated OECs resulted in greater beneficial effects. 展开更多
关键词 olfactory ensheathing cells spinal cord injury cell transplantation low-power laser irradiationn
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EXPERIMENTAL STUDY ON MACRO AND MICRO-STRUCTURE OF METALLIC PARTS BUILT BY LOW-POWER LASER CLADDING 被引量:2
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作者 LiuJichang LiLijun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第2期263-266,共4页
A low-power CO_2 laser is used to deposit Fe powder and mixture of Fe andcarbon powder on substrates respectively, and the macro and micro-structure of the formed samplesare investigated. It is demonstrated that most ... A low-power CO_2 laser is used to deposit Fe powder and mixture of Fe andcarbon powder on substrates respectively, and the macro and micro-structure of the formed samplesare investigated. It is demonstrated that most grains of these samples are equi-axed. This isderived from the high nucleation velocity in the shallow melt pool besides rapid solidification ofthe liquid-state alloy or metal. Bainitic structure, combination of pearlite and ferrite structureand ferrite structure are seen respectively in the samples involving various amounts of carbon owingto no martensitic transformation in these small samples. 展开更多
关键词 laser cladding forming MICRO-STRUCTURE low-power laser
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3D cavity detection technique and its application based on cavity auto scanning laser system 被引量:3
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作者 刘希灵 李夕兵 +2 位作者 李发本 赵国彦 秦豫辉 《Journal of Central South University of Technology》 EI 2008年第2期285-288,共4页
Ground constructions and mines are severely threatened by ones. Safe and precise cavity detection is vital for reasonable cavity underground cavities especially those unsafe or inaccessible evaluation and disposal. Th... Ground constructions and mines are severely threatened by ones. Safe and precise cavity detection is vital for reasonable cavity underground cavities especially those unsafe or inaccessible evaluation and disposal. The conventional cavity detection methods and their limitation were analyzed. Those methods cannot form 3D model of underground cavity which is used for instructing the cavity disposal; and their precisions in detection are always greatly affected by the geological circumstance. The importance of 3D cavity detection in metal mine for safe exploitation was pointed out; and the 3D cavity laser detection method and its principle were introduced. A cavity auto scanning laser system was recommended to actualize the cavity 3D detection after comparing with the other laser detection systems. Four boreholes were chosen to verify the validity of the cavity auto scanning laser system. The results show that the cavity auto scanning laser system is very suitable for underground 3D cavity detection, especially for those inaccessible ones. 展开更多
关键词 cavity detection 3D laser detection cavity auto scanning laser system
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Low-power laser irradiation inhibits arecoline-induced fibrosis:an in vitro study 被引量:2
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作者 Mei-Chun Yeh Ker-Kong Chen +4 位作者 Min-Hsuan Chiang Chia-Hsin Chen Ping-Ho Chen Huey-Er Lee Yan-Hsiung Wang 《International Journal of Oral Science》 SCIE CAS CSCD 2017年第1期38-42,共5页
Oral submucous fibrosis (OSF) is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major ae... Oral submucous fibrosis (OSF) is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major aetiological factor in the development of OSF. Low-power laser irradiation (LPLI) has been reported to be beneficial in fibrosis prevention in different damaged organs. The aim of this study was to investigate the potential therapeutic effects of LPLI on arecoline-induced fibrosis. Arecoline- stimulated human gingival fibroblasts (HGFs) were treated with or without LPLI. The expression levels of the fibrotic marker genes alpha-smooth muscle actin (a-SMA) and connective tissue growth factor (CTGF/CCN2) were analysed by quantitative real- time reverse transcription polymerase chain reaction (RT-PCR) and western blots. In addition, the transcriptional activity of CCN2 was further determined by a reporter assay. The results indicated that arecoline increased the messenger RNA and protein expression of CCN2 and a-SMA in HGF. Interestingly, both LPLI and forskolin, an adenylyl cyclase activator, reduced the expression of arecoline-mediated fibrotic marker genes and inhibited the transcriptional activity of CCN2. Moreover, pretreatment with SQ22536, an adenylyl cyclase inhibitor, blocked LPLI's inhibition of the expression of arecoline-mediated fibrotic marker genes. Our data suggest that LPLI may inhibit the expression of arecoline-mediated fibrotic marker genes via the cAMP signalling pathway. 展开更多
关键词 adenylate cyclase alpha-smooth muscle actin connective tissue growth factor FIBROSIS low-power laser irradiation
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Dynamic obstacles detection of tram based on laser radar 被引量:3
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作者 KUANG Wen-zhen WU Meng-luo XU Li 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第4期316-320,共5页
The detection of obstacles in a dynamic environment is a hot and difficult problem.A method of autonomously detecting obstacles based on laser radar is proposed as a safety auxiliary structure of tram.The nearest neig... The detection of obstacles in a dynamic environment is a hot and difficult problem.A method of autonomously detecting obstacles based on laser radar is proposed as a safety auxiliary structure of tram.The nearest neighbor method is used for spatial obstacles clustering from laser radar data.By analyzing the characteristics of obstacles,the types of obstacles are determined by time correlation.Experiments were carried out on the developed unmanned aerial vehicle(UAV),and the experimental results verify the effectiveness of the proposed method. 展开更多
关键词 laser radar TRAM dynamic obstacle detection spatial obstacle clustering time correlation nearest neigbor method
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Laser ultrasonic technique for surface defects detection of 6061 aluminum alloy 被引量:2
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作者 LI Hai-yang WEI Zhuang-zhuang PAN Qiang-Hua 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第3期293-298,共6页
In order to estimate and detect the surface defect depth of metals, the transmission method of laser ultrasonic surface waves is used in this work. The laser ultrasonic detection platform taking use of thermoelastic m... In order to estimate and detect the surface defect depth of metals, the transmission method of laser ultrasonic surface waves is used in this work. The laser ultrasonic detection platform taking use of thermoelastic mechanism as acoustic signal excitation method and interference receiver as acoustic signal receiver method was built, by which B-scan images of detected specimens with surface defects were collected to establish the relationship between the transmission coefficient and depth of the surface defect. Experimental results show that the amplitude of transmitted acoustic signal is related to the depth of surface defect. At last, a fitted curve of transmission coefficient using measured experimental data is obtained to estimate depth of surface defect on the 6061 aluminum alloy. Furthermore, a surface defect depth of 0.3 mm is estimated by the fitting curve with an estimated error of 16%. Therefore, a experimental method using the transmission method by laser ultrasonic is presented in this paper. 展开更多
关键词 laser ultrasonics transmission method surface defect depth detection
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Implications of using two low-power continuous-wave lasers for polishing 被引量:4
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作者 Wenxuan Zhang Kiwan Wong +2 位作者 Miguel Morales Carlos Molpeceres Craig B Arnold 《International Journal of Extreme Manufacturing》 2020年第3期174-182,共9页
Laser polishing is widely employed to reduce the surface roughness of products with complex geometries.Traditional laser polishing techniques use a single high-power Gaussian beam to melt and smooth a thin layer of su... Laser polishing is widely employed to reduce the surface roughness of products with complex geometries.Traditional laser polishing techniques use a single high-power Gaussian beam to melt and smooth a thin layer of surface material.However,the reliance on high power lasers can present practical challenges such as minimizing surface evaporation or reducing overall cost.In this work,we combined two identical low-power laser beams with a spatial offset in between them to construct an elliptical beam.By changing the spatial offset,combined beams with different lengths along the major axis can be created.We observe over 20%improvement in line roughness reduction using this approach compared to a single Gaussian laser beam with the same total power.Additionally,both experiment and simulation results suggest such improvement is because this dual-laser set-up can create a longer molten pool compared to a single laser. 展开更多
关键词 laser polishing surface roughness dual lasers low-power
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A line laser detection screen design and projectile echo power calculation in detection screen area 被引量:1
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作者 Han-shan Li Xiao-qian Zhang +1 位作者 Xue-wei Zhang Quan-min Guo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第8期1405-1415,共11页
A line laser with high power as the background light source for the design of a new photoelectric detection target is proposed in this paper, aiming to improve the detection ability of the traditional photoelectric de... A line laser with high power as the background light source for the design of a new photoelectric detection target is proposed in this paper, aiming to improve the detection ability of the traditional photoelectric detection target under low background illumination. The laser emitted pulse waveform function and the laser echo pulse response function were used to establish the mathematical model of the reflected echo power of projectile in the detection area and derive the calculation function of minimum detectable echo power in the line laser detection screen, according to information of the line laser emitted power, incident angle of projectile, duration time and detection distance of projectile passing through the line laser detection screen. Calculations and experimental results showed that the design method of line laser detection screen and calculation model of laser echo power are reasonable, and the detection ability of line laser detection screen is obviously higher than that of traditional photoelectric detection screen, especially in low background illumination;at the same time, the designed line laser detection screen was used to combine a six line laser detection screen intersection test system, based on live ammunition for shooting. The test system is stable and able to obtain the dynamic parameters of the flying projectile, verifying that the design of the line laser detection screen in new photoelectric detection target can be suitable for shooting range test applications. 展开更多
关键词 Line laser detection screen Photoelectric detection target Photoelectric detection receiver Echo power PROJECTILE
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Sensitivity function analysis of gravitational wave detection with single-laser and large-momentum-transfer atomic sensors 被引量:2
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作者 Biao Tang Bao-Cheng Zhang +2 位作者 Lin Zhou Jin Wang Ming-Sheng Zhan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第3期333-347,共15页
Recently, a configuration using atomic interferometers (AIs) had been sug- gested for the detection of gravitational waves. A new AI with some additional laser pulses for implementing large momentum transfer was als... Recently, a configuration using atomic interferometers (AIs) had been sug- gested for the detection of gravitational waves. A new AI with some additional laser pulses for implementing large momentum transfer was also put forward, in order to reduce the effect of shot noise and laser frequency noise. We use a sensitivity function to analyze all possible configurations of the new AI and to distinguish how many mo- menta are transferred in a specific configuration. By analyzing the new configuration, we further explore a detection scheme for gravitational waves, in particular, that ame- liorates laser frequency noise. We find that the amelioration occurs in such a scheme, but novelly, in some cases, the frequency noise can be canceled completely by using a proper data processing method. 展开更多
关键词 gravitational wave detection -- atomic interferometer-- laser frequencynoise
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In-Line Inspection of Pipeline Defects Detection Using Ring-Type Laser 被引量:2
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作者 Mathivanan Durai Yang-Min Hsu Ho Chang 《World Journal of Engineering and Technology》 2021年第3期589-603,共15页
Pipeline plays a vital role in transporting fluids like oils, water, and petrochemical substances for longer distances. Based on the materials they carry</span><span style="white-space:normal;font-size:1... Pipeline plays a vital role in transporting fluids like oils, water, and petrochemical substances for longer distances. Based on the materials they carry</span><span style="white-space:normal;font-size:10pt;font-family:"">,</span><span style="white-space:normal;font-size:10pt;font-family:""> prolonged usage may cause the initiation of defects in the pipeline. These defects occur due to the formed salt deposits, chemical reaction happens between the inner surface and the transferring substance, prevailing environmental conditions, etc. These defects, if not identified earlier may lead to significant losses to the industry. In this work, an in-line inspection system utilizes the nondestructive way for analyzing the internal defects in the petrochemical pipeline. This system consists of a pipeline inspection robot having two major units namely the visual inspection unit and the power carrier unit. The visual inspection unit makes use of a ring-type laser diode and the camera. The laser diode serves as a light source for capturing good quality images of inspection. This unit is controlled by the Arduino in the power carrier unit which provides the necessary movement throughout the pipe. The inspected images captured by the camera are further processed with the aid of NI vision assistant software. After applying the processing function parameters provided by this software, the defect location can be clearly visualized with high precision. Three sets of defects are introduced in a Polylactide (PLA) pipe based on its position and angle along the circumference of the pipe. Further, this robot system serves as a real-time interactive image synchronization system for acquiring the inspected images. By comparing the actual and calculated defect size, the error percentage obtained was less than 5%. 展开更多
关键词 Pipeline Robotic System Ring-Type laser Vision Assistant Image Pro-cessing Leak Holes detection Nondestructive Testing
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