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Co-variability Between the Broad Absorption Lines and Narrow Absorption Lines
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作者 Bo-Lin Qin Jing Li Wei-Jian Lu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第9期99-105,共7页
We investigate the relationship between the variability of broad absorption lines(BALs)or narrow absorption lines(NALs)and that of continuum using a data set of two-epoch SDSS spectra containing 134 C IV NAL-BAL pairs... We investigate the relationship between the variability of broad absorption lines(BALs)or narrow absorption lines(NALs)and that of continuum using a data set of two-epoch SDSS spectra containing 134 C IV NAL-BAL pairs.Our analysis reveals an anti-correlation between the fractional equivalent width(EW)variations in NALs(or BALs)and the fractional flux variations of the continuum,with Spearman rank correlation coefficients of r=-0.47(p=1E-08)and r=-0.58(p=1E-13),respectively.In addition,we find a positive correlation between the fractional EW variations in NALs and BALs(r=0.72,p=1E-22),and derive a regression equation ΔEW_(NAL)/<EW_(NAL)>=0.803ΔEW_(BAL)/<EW_(BAL)>+0.008,with an intrinsic scatter of 0.14.These results suggest that the variability in the ionizing continuum may play a significant role in the observed changes in C IV NALs and BALs,supporting the idea of photoionization-driven variability.The co-variability between C IV NALs and BALs may imply that they originate from outflows with similar physical conditions. 展开更多
关键词 (galaxies:)quasars:absorption lines (galaxies:)quasars:general galaxies:active
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Strong optical and UV intermediate-width emission lines in the quasar SDSS J232444.80–094600.3:dust-free and intermediate-density gas at the skin of dusty torus?
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作者 Zhen-Zhen Li Hong-Yan Zhou +3 位作者 Lei Hao Shu-Fen Wang Tuo Ji Bo Liu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第9期107-116,共10页
Emission lines from the broad emission line region (BELR) and the narrow emission line region (NELR) of active galactic nuclei (AGNs) have been extensively studied. However, emission lines are rarely detected be... Emission lines from the broad emission line region (BELR) and the narrow emission line region (NELR) of active galactic nuclei (AGNs) have been extensively studied. However, emission lines are rarely detected between these two regions. We present a detailed analysis of quasar SDSS J232444.80-094600.3 (SDSS J2324-0946), which is remarkable for its strong intermediate-width emission lines (IELs) with FWHM ≈ 1800 km s^-1. The IEL component is present in different emission lines, including the permitted lines Lyαλ1216, CⅣ λ1549, semiforbidden line C Ⅲ] λ1909, and forbidden lines [OⅢ] ss4959, 5007. With the aid of photo-ionization models, we found that the IELs are produced by gas with a hydrogen density of nH - 10^6.2 -- 10^6.3 cm^-3, a distance from the central ionizing source of R - 35 - 50 pc, a covering factor of - 6%, and a dust-to-gas ratio of ≤ 4% that of the SMC. We suggest that the strong IELs of this quasar are produced by nearly dust-free and intermediate-density gas located at the skin of the dusty torus. Such strong IELs, which serve as a useful diagnostic, can provide an avenue to study the properties of gas between the BELR and the NELR. 展开更多
关键词 GALAXIES active -- galaxies nuclei -- quasars emission lines -- individual (SDSSJ2324-0946)
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Variations of broad emission lines from periodicity QSOs under the interpretation of supermassive binary black holes with misaligned circumbinary broad line regions
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作者 Xiang Ji Jun-Qiang Ge +1 位作者 You-Jun Lu Chang-Shuo Yan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第9期63-74,共12页
Quasars with periodic light curves are considered as candidates of supermassive binary black hole(BBH)systems.One way for further confirmations may be searching for other characteristic signatures,such as those in the... Quasars with periodic light curves are considered as candidates of supermassive binary black hole(BBH)systems.One way for further confirmations may be searching for other characteristic signatures,such as those in their broad emission lines(BELs),if any,which require a thorough understanding on the response of BELs to the BBH systems.In Ji et al.(2021),we have investigated the response of circumbinary broad line region(BLR)to the central active secondary black hole under the relativistic Doppler boosting(BBH-DB)and intrinsic variation(BBH-IntDB)dominant mechanisms for continuum variation by assuming the middle plane of the BLR aligned with the BBH orbital plane.In this paper,we explore how the BEL profiles vary when the BLR is misaligned from the BBH orbital plane with different offset angles under both the BBH-DB and BBH-IntDB scenarios.Given a fixed inclination angle of the BBH orbital plane viewed in edge-on and similar continuum light curves produced by the two scenarios,increasing offset angles make the initial opening angle of the circumbinary BLR enlarged due to orbital precession caused by the BBH system,especially for clouds in the inner region,which result in Lorentzlike BEL profiles for the BBH-DB model but still Gaussion-like profiles for the BBH-IntDB model at the vertical BLR case.The amplitude of profile variations decreases with increasing offset angles for the BBHDB scenario,while keeps nearly constant for the BBH-IntDB scenario,since the Doppler boosting effect is motion direction preferred but the intrinsic variation is radiated isotropically.If the circumbinary BLR is composed of a coplanar and a vertical components with their number of clouds following the mass ratio of the BBHs,then the bi-BLR features are more significant for the BBH-IntDB model that requires larger mass ratio to generate similar continuum variation than the BBH-DB model. 展开更多
关键词 black hole physics quasars supermassive black holes emission lines profiles
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SDSS J1042-0018:a Broad Line AGN but Misclassified as an HⅡGalaxy in the BPT Diagram by Flux Ratios of Narrow Emission Lines
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作者 Yi Cao Si-Dan Zhao +3 位作者 Xing-Yu Zhu Hai-Chao Yu Yi-Wei Wang Xue-Guang Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第4期114-122,共9页
In this paper,we discuss properties of SDSS J1042-0018 which is a broad line active galactic nucleus(AGN)but misclassified as an H II galaxy in the BPT diagram(SDSS J1042-0018 is called a misclassified broad line AGN)... In this paper,we discuss properties of SDSS J1042-0018 which is a broad line active galactic nucleus(AGN)but misclassified as an H II galaxy in the BPT diagram(SDSS J1042-0018 is called a misclassified broad line AGN).The emission lines around Hαand around Hβare well described by different model functions,considering broad Balmer lines to be described by Gaussian or Lorentz functions.Different model functions lead to different determined narrow emission line fiuxes,but the different narrow emission line fiux ratios lead SDSS J1042-0018 as an H II galaxy in the BPT diagram.In order to explain the unique properties of the misclassified broad line AGN SDSS J1042-0018,two methods are proposed,the star-forming contributions and the compressed narrow emission line regions with high electron densities near to critical densities of forbidden emission lines.Fortunately,the strong star-forming contributions can be preferred in SDSS J1042-0018.The misclassified broad line AGN SDSS J1042-0018,well explained by star-forming contributions,could provide further clues on the applications of BPT diagrams to the normal broad line AGNs. 展开更多
关键词 active galaxies active galactic nuclei emission line galaxies quasars
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Simulation of the emission lines radiated from cataclysmic variables
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作者 Lin He Guo-Liang Lü Yong-Heng Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第10期1213-1218,共6页
Cataclysmic variables are special celestial bodies because they have particular light curves and spectra.The mechanisms for generating emission lines radiated from dwarf novae in their quiescent phases are studied.We ... Cataclysmic variables are special celestial bodies because they have particular light curves and spectra.The mechanisms for generating emission lines radiated from dwarf novae in their quiescent phases are studied.We assume that the incident radiation field which is emitted by a hot source(white dwarf and boundary layer)irradiates the gaseous layer evaporated from the accretion disk,and the emission lines are radiated from the gas.We model the fluxes of emission lines by using the photoionization code CLOUDY.Using this method,we input some reasonable parameters and get a series of simulated spectra.In order to find a simulated spectrum which is the best fit to an observed spectrum,we use a cross-correlation method to match them.After the calculation,we use the approximation that the parameters of the simulated spectrum can simulate the observed spectrum.Finally,we learn more about the physical conditions of the system. 展开更多
关键词 stars:cataclysmic variables accretion disk:emission lines emission lines:photoionization
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Relations between the IR-UV-X-ray Continuum and Emission Lines for a Large Composite Sample of Narrow Line and Normal Seyfert 1 Galaxies
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作者 You-JunLu Chong-ShanZhao 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2001年第1期39-45,共7页
We report on our research on the UV, optical line parameters and the infrared through UV to soft X-ray continuum parameters for a composite sample of narrow line and normal Seyfert 1 galaxies. The strong correlations ... We report on our research on the UV, optical line parameters and the infrared through UV to soft X-ray continuum parameters for a composite sample of narrow line and normal Seyfert 1 galaxies. The strong correlations among the line width of HB, optical line strength of Fell and the soft X-ray slope are confirmed. We found no correlations between the UV line parameters, the equivalent widths of Lya and CIV and their ratio on one hand and the optical line parameters on the other. The UV and X-ray luminosities strongly correlate with the line widths of HB and the Fe II/HB ratio. No significant correlation is found between the infrared-soft X-my continuum slope aix and the line width of HB. 展开更多
关键词 galaxies: active galactic nuclei (AGN) - emission lines - Ultraviolet: galaxies - galaxies: X-rays
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中国碳排放全要素生产率的区域演进及其影响机制——基于胡焕庸线的实证分析
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作者 吴旭晓 《生态经济》 北大核心 2024年第2期13-21,共9页
提升碳排放全要素生产率是全面建设中国式现代化的内在要求。运用NCSE-EBM与Malmquist Luenberger指数相结合的模型测度和分析2011—2020年我国30个省份碳排放全要素生产率及其区域动态演进特征,并采用灰色关联方法探讨区域碳排放全要... 提升碳排放全要素生产率是全面建设中国式现代化的内在要求。运用NCSE-EBM与Malmquist Luenberger指数相结合的模型测度和分析2011—2020年我国30个省份碳排放全要素生产率及其区域动态演进特征,并采用灰色关联方法探讨区域碳排放全要素生产率演变的影响机制。结果显示:碳排放全要素生产率在空间上表现为胡焕庸线西北和东南区域高、沿线区域低的“V”型分布态势;三大区域碳排放全要素生产率均不存在严格收敛;效率改善指数是碳排放全要素生产率提升的内在主导性因素;产业结构是我国三大区域碳排放全要素生产率的最主要影响因素,技术创新与胡焕庸线西北区域和东南区域碳排放全要素生产率的关联度最低,而数字化与胡焕庸线沿线区域碳排放全要素生产率关联度最小。 展开更多
关键词 碳排放全要素生产率 EBM-Malmquist Luenberger指数模型 灰色综合关联度 胡焕庸线
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Effects of sonic speed on location accuracy of acoustic emission source in rocks 被引量:12
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作者 李启月 董陇军 +2 位作者 李夕兵 殷志强 刘希灵 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第12期2719-2726,共8页
To quantitatively study the location errors induced by deviation of sonic speed, the line and plane location tests were carried out. A broken pencil was simulated as acoustic emission source in the rocks. The line and... To quantitatively study the location errors induced by deviation of sonic speed, the line and plane location tests were carried out. A broken pencil was simulated as acoustic emission source in the rocks. The line and plane location tests were carried out in the granite rod using two sensors and the cube of marble using four sensors, respectively. To compare the position accuracy between line and plane positions, the line poison test was also carried out on the marble surface. The results show that for line positioning, the maximum error of absolute distance is about 0.8 cm. With the speed difference of 200 m/s, the average value of absolute difference from the position error is about 0.4 cm. For the plane positioning, in the case of the sensor array of 30 cm, the absolute positioning distance is up to 8.7 cm. It can be seen that the sonic speed seriously impacts on the plane positioning accuracy. The plane positioning error is lager than the line positioning error, which means that when the line position can satisfy the need in practical engineering, it is better to use the line position instead of the plane location. The plane positioning error with the diagonal speed is the minimum one. 展开更多
关键词 acoustic emission source sonic speed line location plane positioning ROCK
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油田集输站库储罐甲烷逸散规律的连续监测分析
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作者 叶文婷 姚彬 +4 位作者 徐梦瑶 张欣 孙辉 王敏 唐宇嘉 《环境污染与防治》 CAS CSCD 北大核心 2024年第9期1295-1300,1308,共7页
作为油气上游业务的集输站库,其储罐甲烷逸散状况在“碳达峰、碳中和”背景下受到广泛关注。目前通过模型估算的储罐甲烷逸散结果误差大,采样监测因随机性也导致结果不可靠。采用新型有机气体监测仪,对集输站库典型储罐的呼吸和甲烷逸... 作为油气上游业务的集输站库,其储罐甲烷逸散状况在“碳达峰、碳中和”背景下受到广泛关注。目前通过模型估算的储罐甲烷逸散结果误差大,采样监测因随机性也导致结果不可靠。采用新型有机气体监测仪,对集输站库典型储罐的呼吸和甲烷逸散进行了连续监测分析,结果表明:(1)拱顶罐呼吸和甲烷逸散明显,无油气回收系统的拱顶罐最大日呼气累计流量达97.7 m^(3)/d,最大日甲烷逸散量83.05 m^(3)/d;有油气回收系统的拱顶罐日呼气累计流量<1.0 m^(3),日甲烷逸散量≤0.2 m^(3)/d;安装节能呼吸阀后拱顶罐日呼气累计流量和日甲烷逸散量分别降低至原来的20.9%和9.6%;浮顶罐几乎无甲烷逸散。(2)集输站库储罐呼吸日进程和季节特征明显。拱顶罐呼吸活动集中在12:00—18:00时段,高温季节呼吸量明显上升。 展开更多
关键词 甲烷排放 逸散排放 油田集输站库 在线监测
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长江干线“零排放”政策下船舶防污染面临问题及对策研究 被引量:1
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作者 郭锦怡 吴震 +1 位作者 曹立新 田红薇 《交通节能与环保》 2024年第2期20-23,共4页
长江干线船舶往来频繁,常年运营船舶20万条左右,船舶在航行过程产生的污染物对水域环境产生潜在影响。为从源头上防治船舶污染,自2020年起,重庆地区率先实施船舶水污染物“船上储存、交岸处置”的“零排放”治理模式,取得了一定的成效,... 长江干线船舶往来频繁,常年运营船舶20万条左右,船舶在航行过程产生的污染物对水域环境产生潜在影响。为从源头上防治船舶污染,自2020年起,重庆地区率先实施船舶水污染物“船上储存、交岸处置”的“零排放”治理模式,取得了一定的成效,目前“零排放”治理模式已基本覆盖长江干线。本文梳理了长江干线船舶防污染法律法规、“零排放”实施背景和现状,提出“零排放”政策下船舶污染面临的问题并给出了对策建议,为下一步船舶防污染工作提供借鉴和思路。 展开更多
关键词 船舶防污染 零排放 问题及对策 长江干线
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高能X射线光谱分析工具——SasalPy
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作者 郝明月 梁贵云 +1 位作者 王凯 毛俊捷 《原子与分子物理学报》 北大核心 2024年第4期99-113,共15页
等离子体模型是天文学家解析高能天体观测数据的重要工具,发展精确便利的等离子体模型有助于研究者高效的进行高能X射线光谱分析工作.在现有的SASAL等离子体模型的基础上进一步提出一种新的基于Python语言的高能X射线光谱分析工具包Sasa... 等离子体模型是天文学家解析高能天体观测数据的重要工具,发展精确便利的等离子体模型有助于研究者高效的进行高能X射线光谱分析工作.在现有的SASAL等离子体模型的基础上进一步提出一种新的基于Python语言的高能X射线光谱分析工具包SasalPy,并从理论框架、功能性和差异性方面阐述SasalPy的可靠性和精确性.线辐射和连续辐射计算结果表明,原子参数如跃迁速率、碰撞强度等会对合成光谱产生明显地影响.以Capella星冕的体微分发射度为基础开展了三个温度的光谱合成应用,并通过与其他等离子体模型辐射损失结果的对比,说明SasalPy在X射线能段比较精确可靠. 展开更多
关键词 等离子体模型 高能X射线 线辐射 连续辐射 合成光谱 辐射损失
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液体火箭发动机尾焰金属发射光谱仿真与实验研究
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作者 苏童 雷庆春 范玮 《推进技术》 EI CAS CSCD 北大核心 2024年第2期105-113,共9页
液体火箭发动机尾焰包含丰富的光谱信息,可以作为检测发动机运行状态与故障情况的重要依据。本文建立了高精度的液体火箭发动机尾焰金属发射光谱数值模拟方法,该方法以逐线法(Line-by-Line,LBL)为基础,考虑介质的光学厚度影响。利用该方... 液体火箭发动机尾焰包含丰富的光谱信息,可以作为检测发动机运行状态与故障情况的重要依据。本文建立了高精度的液体火箭发动机尾焰金属发射光谱数值模拟方法,该方法以逐线法(Line-by-Line,LBL)为基础,考虑介质的光学厚度影响。利用该方法,对液体火箭发动机发生故障时,尾焰中可能存在的铁、镍、钾发射光谱进行了数值模拟,模拟结果与NASA光谱模拟程序所得结果相吻合。最后,在甲烷-氧气、乙烯-氧气预混火焰开展了铁、钾发射光谱的实验验证,结果表明,以光谱面积与特征峰强度为对比参数,光谱模拟结果和实验结果的相对误差在2.5%以下,利用实验数据,进一步讨论了光学薄和光学厚两种模型的适用性。 展开更多
关键词 液体火箭发动机 原子发射光谱 数值模拟 光学厚度 逐线法
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部分拆装线平衡问题的多目标人工蜂群算法
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作者 杨琬琳 李梓响 +3 位作者 郑晨昱 张子凯 张利平 唐秋华 《组合机床与自动化加工技术》 北大核心 2024年第10期181-186,192,共7页
拆卸线广泛应用于拆解报废产品,当前大多数的研究关注于废弃产品的完全拆卸,缺乏对拆卸利润和节省碳排放量等的研究。针对部分拆装线平衡,构建了面向利润、节省碳排放量和线平衡的多目标数学模型。为实现问题的高效求解,设计了改进多目... 拆卸线广泛应用于拆解报废产品,当前大多数的研究关注于废弃产品的完全拆卸,缺乏对拆卸利润和节省碳排放量等的研究。针对部分拆装线平衡,构建了面向利润、节省碳排放量和线平衡的多目标数学模型。为实现问题的高效求解,设计了改进多目标人工蜂群算法。该算法采取操作排序向量和拆卸零部件数量的双层编码,同时设计双层解码以分别处理优先关系约束和节拍约束。该算法雇佣蜂阶段采取邻域操作、跟随蜂阶段采取交叉操作以获得差异化的种群,同时侦察蜂阶段采取从永久帕累托前沿选择一个解来替换抛弃的个体以获得高性能的新解。为了测试改进算法的性能,该算法与原始多目标人工蜂群算法、多目标模拟退火算法、快速非支配遗传算法进行对比。测试结果表明改进策略有效提升了人工蜂群算法的性能,同时改进人工蜂群算法优于对比的算法,可实现多目标拆卸线平衡问题的高效求解。 展开更多
关键词 部分拆卸线平衡 碳排放 多目标优化 多目标人工蜂群算法
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Summary of a Life in Observational Ultraviolet/Optical Astronomy
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作者 Donald G.York 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期1-43,共43页
I reminisce on my early life in Section 1;on my education in Sections 2 and 3;on the years at Princeton as a research astronomer in Section 4;on the years on the faculty at Chicago in Section 5;on research on Diffuse ... I reminisce on my early life in Section 1;on my education in Sections 2 and 3;on the years at Princeton as a research astronomer in Section 4;on the years on the faculty at Chicago in Section 5;on research on Diffuse Interstellar Bands(DIBs) in Section 6;on construction of the 3.5 m telescope at Apache Point Observatory(APO)in Section 7;on work on the Sloan Digital Sky Survey(SDSS) in Section 8;on work in public education in Chicago in Section 9;and on my travels in Section 10. My main science research is of an observational nature,concerning Galactic and intergalactic interstellar gas. Highlights for me included my work on the orbiting telescope Copernicus, including the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxygen;and discoveries concerning the phases of gas in the local interstellar medium, based on previously unobservable interstellar UV spectral lines. With other instruments and collaborations, I extended interstellar UV studies to the intergalactic cool gas using quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morphological character of the source of absorption lines in QSO spectra;and pursued the identification of the unidentified DIBs. For several of these topics, extensive collaborations with many scientists were essential over many years. The conclusions developed slowly, as I moved from being a graduate student at Chicago, to a research scientist position at Princeton and then to a faculty position at Chicago. At each stage of life, I was exposed to new technologies adaptable to my science and to subsequent projects. From high school days, I encountered several management opportunities which were formative. I have been extremely fortunate both in scientific mentors I had and in experimental opportunities I encountered. 展开更多
关键词 Interstellar Medium(ISM) NEBULAE (galaxies:)quasars:absorption lines ultraviolet:stars
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Quantized Redshift and its Significance for Recent Observation
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作者 Arindam Mal Sarbani Palit +1 位作者 Christopher C.Fulton Sisir Roy 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第9期156-166,共11页
With the recent observational evidence in extragalactic astronomy,the interpretation of the nature of quasar redshift continues to be a research interest.Very high redshifts are being detected for extragalactic object... With the recent observational evidence in extragalactic astronomy,the interpretation of the nature of quasar redshift continues to be a research interest.Very high redshifts are being detected for extragalactic objects that are presumably very distant and young while also exhibiting properties that are characteristic of a more mature galaxy such as ours.According to Halton Arp and Geoffrey Burbidge,redshift disparities consist of an intrinsic component and are related to an evolutionary process.Karlsson observed redshift periodicity at integer multiples of0.089 in log scale and Burbidge observed redshift periodicity at integer multiples of 0.061 in linear scale.Since Singular Value Decomposition based periodicity estimation is known to be superior for noisy data sets,especially when the data contain multiple harmonics and overtones,mainly irregular in nature,we have chosen it to be our primary tool for analysis of the quasar-galaxy pair redshift data.We have observed a fundamental periodicity of0.051 with a confidence interval of 95%in linear scale with the site-available Sloan Digital Sky Survey Data Release 7(SDSS DR7)quasar-galaxy pair data set.We have independently generated quasar-galaxy pair data sets from both 2d F and SDSS and found fundamental periodicities of 0.077 and 0.089,respectively,in log scale with a confidence interval of 95%. 展开更多
关键词 galaxies:distances and redshifts (galaxies:)quasars:absorption lines cosmology:observations
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移动式钻井平台零排放技术浅析
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作者 杨志 李春 +1 位作者 陈国军 张居贵 《当代石油石化》 CAS 2024年第1期42-46,共5页
近年来,随着全民环保意识不断增强,政府相继出台了系列环保法规,加强对污染物的排放控制。根据渤海地区生态红线保护要求,以实现移动式钻井平台作业过程零污染为目标,定量分析了海洋钻探开发过程中固体污染物、生活污水、工业污水等排放... 近年来,随着全民环保意识不断增强,政府相继出台了系列环保法规,加强对污染物的排放控制。根据渤海地区生态红线保护要求,以实现移动式钻井平台作业过程零污染为目标,定量分析了海洋钻探开发过程中固体污染物、生活污水、工业污水等排放量,优化钻井平台原液舱功能分布,校核了钻井平台结构强度与稳性,实现海洋钻探过程中的污染物零排放技术方案。相关技术成果已成功应用于多个钻井平台,可推广至同类大型海洋作业装备。 展开更多
关键词 生态红线 移动式钻井平台 零排放 定量分析 结构校核
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恒星光谱数据弱特征识别方法
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作者 贺艳婷 周嘉炜 +3 位作者 杨雨晴 贾凯雪 唐文龙 杨海峰 《太原科技大学学报》 2024年第2期137-142,共6页
恒星光谱弱特征识别是LAMOST光谱数据分析的重要研究内容,能够为恒星光谱分类提供重要科学依据。目前,针对恒星光谱数据进行特征识别的方法较多,但是缺乏对某种特定特征谱线进行精确提取的算法。针对LAMOST低分辨光谱数据中Hα弱发射线... 恒星光谱弱特征识别是LAMOST光谱数据分析的重要研究内容,能够为恒星光谱分类提供重要科学依据。目前,针对恒星光谱数据进行特征识别的方法较多,但是缺乏对某种特定特征谱线进行精确提取的算法。针对LAMOST低分辨光谱数据中Hα弱发射线轮廓形态多样问题,提出了一种基于置信度的Hα弱发射线识别方法。首先,基于Hα弱发射线轮廓形态特征给出Hα弱发射线的置信度的度量方法。利用Hα发射线波长区间内峰值与发射线的偏移量建立距离置信度模型,根据高斯轮廓所含像素点个数建立高斯轮廓副信息模型,通过计算峰值左右波形的差异建立对称性评估模型,结合三个模型给出最终的Hα弱发射线的置信度,并基于此置信度进行第一轮筛选。为了提高精度,提出了借助其它发射线的特征给出了基于二分类的Hα发射线筛选策略。通过考察Hβ、NII、OIII以及SII发射线的特征,基于辅助信息的决策树进行第二轮筛选,进一步提高筛选的精度。实验结果表明:提出的Hα弱发射线的特征度量方法的准确度高达90%,并且速度较快,平均每1 k数据耗时仅三十多秒。 展开更多
关键词 决策树 二元分类 置信度 弱发射线 LAMOST光谱数据
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“三线一单”生态环境分区管控减污降碳协同控制技术路径实践 被引量:1
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作者 牛韧 于雷 +6 位作者 苗晓东 桑彦彦 薛强 王焕之 张南南 张旭亚 秦昌波 《环境影响评价》 2024年第3期13-20,共8页
开展“三线一单”生态环境分区管控减污降碳协同控制研究,对促进形成与碳达峰碳中和工作统筹协调的生态环境分区管控体系具有重要作用。参照《“三线一单”减污降碳协同管控试点工作方案》,梳理了技术思路与路线;通过分析临沂、广州、... 开展“三线一单”生态环境分区管控减污降碳协同控制研究,对促进形成与碳达峰碳中和工作统筹协调的生态环境分区管控体系具有重要作用。参照《“三线一单”减污降碳协同管控试点工作方案》,梳理了技术思路与路线;通过分析临沂、广州、烟台、福州等城市的试点实践成果,对“三线一单”生态环境分区管控减污降碳协同管控技术路径的关键环节进行了归纳总结,并从数据基础、技术规范和成果应用等方面提出了工作建议。研究成果可为完善“三线一单”生态环境分区管控技术规范提供科学参考。 展开更多
关键词 “三线一单” 生态环境分区管控 减污降碳协同管控
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一种CE102 能力验证方法及实例
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作者 米进才 宋俊 +2 位作者 陈辉 余海涛 张军马 《安全与电磁兼容》 2024年第2期91-97,共7页
文章给出了一种多样品并行传递的CE102能力验证方法及实例,自主研发并制备47套均匀性、稳定性符合要求的能力验证样品,在40家参加实验室中并行分发该样品,相比传统的单样品轮流传递的方式,极大缩短了测试时间,且消除了无备用样品带来的... 文章给出了一种多样品并行传递的CE102能力验证方法及实例,自主研发并制备47套均匀性、稳定性符合要求的能力验证样品,在40家参加实验室中并行分发该样品,相比传统的单样品轮流传递的方式,极大缩短了测试时间,且消除了无备用样品带来的风险。使用稳健算法计算稳健平均值并将其作为指定值,使用GB/T 6113.402-2018中给出的测量不确定度计算能力评定标准差,并将其用于评价参加实验室是否离群。最后对离群的原因进行了分析并提出了改进意见。 展开更多
关键词 电磁兼容 能力验证 CE102电源线传导发射 指定值 能力评定标准差
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金属疲劳损伤在线监测方法综述
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作者 张奎良 贾朋刚 +2 位作者 李海军 许佳丽 李婳 《上海大中型电机》 2024年第2期38-41,共4页
疲劳在线监测的主要目标是监测疲劳裂纹萌生及获得疲劳裂纹扩展速率,从而提供预警。声发射在线监测技术因其能实现对构件的疲劳失效历程开展实时、在线监测,而在疲劳失效在线监测方面得到了普遍的使用。本文简要介绍了应变片监测和光纤B... 疲劳在线监测的主要目标是监测疲劳裂纹萌生及获得疲劳裂纹扩展速率,从而提供预警。声发射在线监测技术因其能实现对构件的疲劳失效历程开展实时、在线监测,而在疲劳失效在线监测方面得到了普遍的使用。本文简要介绍了应变片监测和光纤Bragg光栅监测技术,重点介绍了声发射技术在发电设备方面的疲劳失效过程的在线监测研究进展。 展开更多
关键词 疲劳损伤 裂纹扩展 声发射 在线监测
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