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	Optimization of focusing position in laser induced breakdown spectroscopy system based on quantitative analysis internal standard method of steel 会议论文 OAI收割 Kunming, China, 2021-12-07 作者: Li, Zhicong; Yang, Jianfeng; Wang, Zhiyuan; Zhao, Yiyi; Huang, Shuaidong \| 收藏 \| 浏览/下载：53/0 \| 提交时间：2022/04/27 Laser induced breakdown spectroscopy(LIBS) Quantitative analysis Focus position Detection sensitivity Limit of detection(LOD)
	No pulsed radio emission during a bursting phase of a Galactic magnetar 期刊论文 OAI收割 Nature, 2020, 卷号: 587, 页码: 63-65 作者: HXMT \| 收藏 \| 浏览/下载：51/0 \| 提交时间：2022/02/08 Astrophysics - High Energy Astrophysical Phenomena Abstract: Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft íray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft íray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-íray repeater (SGR) bursts were detected in íray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.
	Constraining the X-Ray-Infrared Spectral Index of Second-timescale Flares from SGR 1935+2154 with Palomar Gattini-IR 期刊论文 OAI收割 The Astrophysical Journal, 2020, 卷号: 901, 页码: L7 作者: HXMT \| 收藏 \| 浏览/下载：27/0 \| 提交时间：2022/02/08 Radio transient sources Magnetars Soft gamma-ray repeaters 2008 992 1471 Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Instrumentation and Methods for Astrophysics Abstract: The Galactic magnetar SGR 1935+2154 has been reported to produce the first example of a bright millisecond-duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs). The detection of a coincident bright X-ray burst represents the first observed multiwavelength counterpart of an FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared (NIR) wavelengths using the Palomar Gattini-IR observing system in the J band, enabled by a novel detector readout mode that allows short exposure times of ?0.84 s with 99.9% observing efficiency. With a total observing time of ?12 hr (?47,728 images) during its 2020 outburst, we place median 3Ҡlimits on the second-timescale NIR fluence of ?18 Jy ms (13.1 AB mag). The corresponding extinction-corrected limit is ?125 Jy ms for an estimated extinction of A_J = 2.0 mag. Our observations were sensitive enough to easily detect an NIR counterpart of FRB 200428 if the NIR emission falls on the same power law as observed across its radio to X-ray spectrum. We report nondetection limits from epochs of four simultaneous X-ray bursts detected by the Insight-HXMT and NuSTAR telescopes during our observations. These limits provide the most stringent constraints to date on fluence of flares at 10¹⁴ Hz, and constrain the fluence ratio of the NIR emission to coincident X-ray bursts to R_NIR ? 0.025 (fluence index ?0.35).
	Laser Induced Breakdown Spectroscopy for Comparative Quantitative Analysis of Betel Leaves from Pakistan 期刊论文 OAI收割 SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 卷号: 38, 期号: 10, 页码: 3295-3302 作者: Rehan, K.; Muhammad, R.; Sultana, S.; Rehan, I \| 收藏 \| 浏览/下载：46/0 \| 提交时间：2018/12/17 Laser induced breakdown spectroscopy (LIBS) Spectral analysis Inductively coupled plasma-optical emission spectrometry Limit of detection (LOD)
	LIBS Detection of Heavy Metal Elements in Liquid Solutions by Using Wood Pellet as Sample Matrix 期刊论文 OAI收割 PLASMA SCIENCE & TECHNOLOGY, 2014, 卷号: 16, 页码: 598-601 作者: Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong \| 收藏 \| 浏览/下载：19/0 \| 提交时间：2018/07/05 Libs Limit Of Detection Cr Element
	液体射流双脉冲激光诱导Ca等离子体发射光谱研究期刊论文 OAI收割中国激光, 2013, 卷号: 40 作者: 张巧; 胡振华; 丁蕾; 王颖萍; 郑海洋 \| 收藏 \| 浏览/下载：8/0 \| 提交时间：2023/11/10 laser technology dual pulse laser laser-induced breakdown spectroscopy laser plasma liquid jet limit of detection 激光技术双脉冲激光激光诱导击穿光谱激光等离子体液体射流检测限
	Study on the detection sensitivity of APS star tracker (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Li J.; Li J.; Li J.; Liu J.; Liu J. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 Detection sensitivity is an important parameter of star tracker which can express detection limit of the weakest detected visual star magnitude. Detection sensitivity of APS star tracker is related to APS parameters optical system aperture and lens permeance rate SNR and so on. This paper the expressions of APS star detected signal and APS noise are given so signal-noise ratio (SNR) of star tracker can be obtained. And based on the theory inspecting signal from noise and optimal SNR threshold detection principle the detection sensitivity model can be obtained. The corresponding APS star tracker detection limit is obtain based on APS IBIS5 and general optical system parameter design. When SNR threshold is 8.1 which can obtain 99.9% detection probability we can calculate that the detection sensitivity is 6.5 visual magnitude.
	The Information acquirement of hyperspectral detection system with harmonic diffractive element in infrared dual band (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China 作者: Zhang Y.; Gao Y. 收藏 \| 浏览/下载：22/0 \| 提交时间：2013/03/25 A novel design of combination of hybrid system and zoom system in hyperspectral detection imaging is discribed based on the application of harmonic diffractive element (HDE) compared with conventional system. The principles of HDE and infrared zoom hyspectral detection system are presented and the results of a example design are given. It is show that the resolution of this hybrid system is improved and the light power received by Cassegrain system is enlarged. Wavefront aberrations are less than 1/4 wavelength and Modulation Transfer Function in the dual band on each zoom focus location approaches or attains the diffraction limit on 20 cycles/mm.
	A study of interaction between FITC- labeled antibody and optical fiber surface (EI CONFERENCE) 会议论文 OAI收割 ICO20: Materials and Nanostructures, August 21, 2005 - August 26, 2005, Changchun, China 作者: Wang X.; Wang X.; Wang X. 收藏 \| 浏览/下载：44/0 \| 提交时间：2013/03/25 The immobilization of antibodies on solid surface has been widely studied in elucidating immunoassay and in developing immunosensor. In this paper FITC-labeled goat anti-human IgG were covalently immobilized on 3-aminopropyltriethoxysilane (APTES) and glutaraldehyde (Glu) to modify the distal end of a fiber-optic probe. The higher density and stability of FITC-labeled goat anti-human IgG could be obtained on the fiber surface modified with APTES-Glu than that on the non-modified fiber surface by evanescent excited fluorescence spectroscopy. Furthermore red shift of the FITC fluorescence dye emission peak was observed on different fiber surface exhibiting different interaction between FITC- labeled antibody and surface. Finally under these conditions antigen-antibody reaction was investigated as an immunosensor. Detection limit of the evanescent wave optic-fiber biosensor is 10ng/ml.