期刊文献+
共找到120篇文章
< 1 2 6 >
每页显示 20 50 100
Detecting land subsidence near metro lines in the Baoshan district of Shanghai with multi-temporal interferometric synthetic aperture radar 被引量:4
1
作者 Tao Li Guoxiang Liu +3 位作者 Hui Lin Rui Zhang Hongguo Jia Bing Yu 《Journal of Modern Transportation》 2014年第3期137-147,共11页
Land subsidence is a major factor that affects metro line (ML) stability. In this study, an improved multi- temporal interferometric synthetic aperture radar (InSAR) (MTI) method to detect land subsidence near M... Land subsidence is a major factor that affects metro line (ML) stability. In this study, an improved multi- temporal interferometric synthetic aperture radar (InSAR) (MTI) method to detect land subsidence near MLs is presented. In particular, our multi-temporal InSAR method provides surface subsidence measurements with high observation density. The MTI method tracks both point-like targets and distributed targets with temporal radar back- scattering steadiness. First, subsidence rates at the point targets with low-amplitude dispersion index (ADI) values are extracted by applying a least-squared estimator on an optimized freely connected network. Second, to reduce error propagation, the pixels with high-ADI values are classified into several groups according to ADI intervals and processed using a Pearson correlation coefficient and hierarchical analysis strategy to obtain the distributed targets. Then, nonlinear subsidence components at all point-like and distributed targets are estimated using phase unwrapping and spatiotemporal filtering on the phase residuals. The proposed MTI method was applied to detect land subsidence near MLs of No. 1 and 3 in the Baoshan district of Shanghai using 18 TerraSAR-X images acquired between April 21, 2008 and October 30, 2010. The results show that the mean subsidence rates of the stations distributed along the two MLs are -12.9 and -14.0 ram/year. Furthermore, three subsidence funnels near the MLs are discovered through the hierarchical analysis. The testing results demonstrate the satisfactory capacity of the proposed MTI method in providing detailed subsidence information near MLs. 展开更多
关键词 Multi-temporal InSAR - Subsidence Baoshan district - Shanghai Metro lines
下载PDF
MiR-25-3p attenuates the proliferation of tongue squamous cell carcinoma cell line Tca8113 被引量:3
2
作者 Jia-Ying Xu Li-Li Yang +3 位作者 Chao Ma Yuan-Liang Huang Gui-Xiang Zhu Qi-Lin Chen 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第9期743-747,共5页
Objective:To investigate the effects of miR-25-3p on the occurrence,development and proliferation of tongue squamous cell carcinoma cells.Methods:To establish tongue squamous cell carcinoma cell line Tca8113 that stab... Objective:To investigate the effects of miR-25-3p on the occurrence,development and proliferation of tongue squamous cell carcinoma cells.Methods:To establish tongue squamous cell carcinoma cell line Tca8113 that stably and highly express miR-25-3p using recombinant reiroviral vector-mediated gene transfer method.The proliferation of transfected Tca8113 was detected by thiazolyl blue tetrazolium bromide(MTT)and cell colony formation assays.eyclnD1,p21^(cipt)and p27^(kipt)mRNA expressions in the transfected Tca-8113 were detected by quantitative PCR.cyclinD1,p21^(cipt),p27^(kipt),AKT,p-AKT,FOXOt and p-FOX01 expressions in the transfected Tca8113 were detected by western blot analysis.In addition,miR-25-3p expression in the tongue squamous cell carcinoma cell line and tissue specimen was also detected by quantitative PCR.Results:Quantitative PCR showed that mitt-25-3p expression in the tongue squamous cell carcinoma cell lines and tissue specimen was significantly lower than that in the adjacent tissue.MTT and cell colony formation assays showed that after miR-25-3p overexpression,the proliferation of transfected Tca8113 was obviously attenuated.Western blot analysis and quantitative PCR showed that after miR-25-3p overexpression.p21^(cipt)and p27^(kipt)expressions were upregulated,while cyclinD1,AKT,FOXO1 expressions were downregulated,and AKT and FOXO1 phosphorylation was inactivated in the transfected Tca8113 cells.Conclusions:MiR-25-3p inhibited the proliferation of tongue squamous cell carcinoma cells and regulated cell cycle-related protein expression,playing an important role in the occurrence and development of squamous cell carcinoma of the tongue. 展开更多
关键词 MiR-25-3p Tongue SQUAMOUS CELL carcinoma Cellular PROLIFERATION RETROVIRUS Stable CELL line AKT/FOXO1
下载PDF
Discovery of a variable broad absorption line in the BL Lac object PKS B0138-097 被引量:1
3
作者 Shao-Hua Zhang Hui-Yuan Wang +2 位作者 Hong-Yan Zhou Ting-Gui Wang Peng Jiang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第10期1163-1170,共8页
We report the discovery of a broad absorption line (BAL) of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of... We report the discovery of a broad absorption line (BAL) of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of a BAL, which is sometimes seen in powerful quasars with high accretion rates, in a BL Lac object. The BAL was clearly detected in its spectra spanning two epochs at a high luminosity state taken in the Sloan Digital Sky Survey (SDSS), while it disappeared in three SDSS spectra taken at a low luminosity state. The BAL and its variability pattern were also found in its historical multi-epoch spectra in the literature, but have been overlooked previously. In its high resolution radio maps, PKS 0138-097 shows a core plus a one- sided parsec-scale jet. The BAL variability can be interpreted as follows: The optical emission is dominated by the core in a high state and by the jet in a low state and the BAL material is located between the core and jet so that the BAL appears only when the core is shining. Our discovery suggests that outflows may also be produced in active galactic nuclei at a low accreting state. 展开更多
关键词 GALAXIES active -- galaxies absorption lines -- BL Lacertae objects individual (PKS 0138-097)
下载PDF
Magneto-induced Line Broadening of Magneto-sensitive Lines in Solar Magnetized Atmospheres 被引量:1
4
作者 Zhong-Quan Qu Shuai Wang +3 位作者 Cheng-Lin Xu Xiao-Yu Zhang Ming-Guo Sun Chun-Lan Jin 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第4期426-432,共7页
We analyze the spectral line broadening of those magneto-sensitive lines in solar magnetized atmospheres. The broadening at the line wings is due to the increase of the effective width of energy levels involved in Zee... We analyze the spectral line broadening of those magneto-sensitive lines in solar magnetized atmospheres. The broadening at the line wings is due to the increase of the effective width of energy levels involved in Zeeman splitting,and the broadening at the line core also originated in Zeeman splitting under the condition that the Zeeman components are mixed. Therefore, the magneto-induced or Zeeman broadening take effects on the whole line. The observed Stokes parameter data in a sunspot and outside it acquired by Solar Stokes Spectrum Telescope (S^3T) are analyzed for the demonstration of this mechanism, and the Zeeman broadening rates are calculated for Fe16302.5 under some assumptions.Our result shows that the broadening is increased as the magnetic field strength becomes stronger, but the rate of increase at the line core is decreased as the field strength increases, while the rate at the wing does not show such an obvious regularity. The broadening is more effective in the line core than in the wings. 展开更多
关键词 sunspots - line profiles-magnetic fields - radiative transfer-polarization
下载PDF
Line Broadening in a Limb Flare: Derivation of Macro-turbulent Velocity Fields 被引量:1
5
作者 Ying Liu and Ming-De DingDepartment of Astronomy, Nanjing University, Nanjing 210093 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2002年第3期277-286,共10页
The line profiles of Ha in a limb flare on 1998 November 11 appear to be unusually broadened. It is considered that macro-turbulence (or macroscopic mass motions) may be one of the main causes. We use an inversion tec... The line profiles of Ha in a limb flare on 1998 November 11 appear to be unusually broadened. It is considered that macro-turbulence (or macroscopic mass motions) may be one of the main causes. We use an inversion technique to extract the probability distribution of the line-of-sight velocity in the flare. There exist some differences between the velocity distributions deduced from Ha and from Ca II λ8542, which may be because the two lines depend differently on the temperature and velocity. Since the loop density is high, we obtain a rather short cooling time (several tens of seconds) from the hot X-ray loops to the cool loops visible in Ha. Possible origins of the large scale motions are discussed. 展开更多
关键词 Sun: flares - Sun: atmospheric motions - line: profiles
下载PDF
THE DIFFERENTIATION OF HUMAN GASTRIC ADENOCAR-CINOMA CELL LINE MGc80-3 INDUCED BY DIBUTYRYL cAMP IN VITRO 被引量:2
6
作者 李祺福 汪德耀 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1991年第1期7-13,共7页
For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocar-cinoma cell line MGc80-3 was induced by dBcAMP in vitro to appraise the ef... For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocar-cinoma cell line MGc80-3 was induced by dBcAMP in vitro to appraise the effect of gastric carcinoma cell differentiation by chemical inducers.Under light microscope, MGc80-3 cells, after treated with 1 mM dBcAMP, tended to be flat and disperse, and their volume gradually enlarged, with their uncleus relatively smaller and their shape rather regular. Morphological changes, like norma differentiated epithelial cells, were observed. The cells attached firmly, grew slowly, their growth curve showed inhibitory rate amounted to 52.87%, and cellular division exponent displayed their peak value 1.5 times less than that of MGc80-3 cells. It was clear that dBcAMP could effectively inhibit the multiplication activity of MGc80-3 cells. After dBcAMP treatment, remarkable changes of cell surface charges was indicated by cell electrophoresis, the ratio dropped to 3.043 from 3.988, and their re-tardant ratio reached up to 31.2%. cAMP content in cells after this treatment, detected by cAMP and cGMP radioimmunoassay, was enhanced by 2.42 times, and cAMP/cGMP ratio, by 1.73 times. Thus, cAMP level within MGc80-3 cells was raised obviously by dBcAMP. Heterotransplantation experiments showed that tuntorigenic rate of MGc80-5 cells (transplanted subcutaneously to BALB/c mice) amounted to 100%, and that of the cells after this treatment was only 5.6%. Their tumorigenic ability was extremely reduced.These results confirmed that dBcAMP was able to change malignant phenotypic characteristics of MGc80-3 cells and produce a reversed alteration: Thus, it has a remarkable inductive effect in differentiating gastric carcinoma cells. All these characteristics were also considered as the reference indexes in appraising reversed effect for the homologous cancer cells. 展开更多
关键词 THE DIFFERENTIATION OF HUMAN GASTRIC ADENOCAR-CINOMA CELL line MGc80-3 INDUCED BY DIBUTYRYL cAMP IN VITRO
下载PDF
A search for evidence of small-scale inhomogeneities in dense cores from line profile analysis
7
作者 Lev Pirogov 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第8期97-102,共6页
In order to search for intensity fluctuations on the HCN(1-0) and HCO+(1-0) line pro- files, which could arise due to possible small-scale inhomogeneous structure, long-term observations of high-mass star-forming... In order to search for intensity fluctuations on the HCN(1-0) and HCO+(1-0) line pro- files, which could arise due to possible small-scale inhomogeneous structure, long-term observations of high-mass star-forming cores S140 and S199 were carried out. The data were processed by the Fourier filtering method. Line temperature fluctuations that exceed the noise level were detected. Assuming the cores consist of a large number of randomly moving small thermal fragments, the total number of frag- ments is - 4 × 106 for the region with linear size - 0.1 pc in S140 and - 106 for the region with linear size - 0.3 pc in S 199. Physical parameters of fragments in S 140 were obtained from detailed modeling of the HCN emission in the framework of the clumpy cloud model. 展开更多
关键词 lineS profiles - molecular data - methods data analysis - ISM clouds - ISM molecules - ISM structure - ISM individual objects (S 140)
下载PDF
ESTABLISHMENT OF A MAMMARY CANCER CELL LINE Ca 761-86 AND ITS BIOLOGICAL CHARACTERISTICS IN INBRED 615 MICE
8
作者 程一棹 黄敏 +5 位作者 王明俭 郑怀祖 袁保和 许广源 程佳 钱振超 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1989年第4期43-48,共6页
A cell line designated as Ca 761-86 has been established from the solid mouse mammary cancer (Ca 761) by suspension culture. It has been passaged for more than 212 generations. Moderate round cells were predominant an... A cell line designated as Ca 761-86 has been established from the solid mouse mammary cancer (Ca 761) by suspension culture. It has been passaged for more than 212 generations. Moderate round cells were predominant and most of them were mononuclear. Some characteristics of malignant cells and A-type viral-like particles were observed by electron microscopy. The results of cytochemical studies (DNA, RNA, SDH, 5' AMPase, ACP etc.) were comparable to the ultramicroscopic results. It multiplied approximately 27.4 fold on day 5 with mitotic index reaching 1.8% on day 3. This cell line was a hyperdiploid with karyotype of 45 or 45, -2X, tril2, tri17, +M1-5. Cell agglutination was observed when treated with ConA (≥7 fig, ml). Spontaneous agglutination might also take place without adding any ConA. After 5×106 cells of Ca 761-86 suspension were transplanted into the normal inbred 615 mice by different ways (subcutan eous, intrafoot-pad or intraperitoneal), the transplan lability rate reached 100%. Spontaneous remission was never observed and its metastatic ability reserved. PPLO were not detected. Ca 761-86 may be of value for practical purposes. 展开更多
关键词 line ESTABLISHMENT OF A MAMMARY CANCER CELL line Ca 761-86 AND ITS BIOLOGICAL CHARACTERISTICS IN INBRED 615 MICE RER ConA CA
下载PDF
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?
9
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)
下载PDF
Effect of DRB on the Biological Characteristics of Human Laryngeal Carcinoma Hep-2 Cell Line
10
作者 王建亭 龚树生 +3 位作者 付勇 薛秋红 陈广理 刘英鹏 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2007年第1期104-106,共3页
In order to study the effect of 5, 6-Dichloro-l-13-D-ribofuranosyl-benzimidazole (DRB) on the biological characteristics of human laryngeal carcinoma Hep-2 cell line in vitro, Hep-2 cells cultured in vitro were trea... In order to study the effect of 5, 6-Dichloro-l-13-D-ribofuranosyl-benzimidazole (DRB) on the biological characteristics of human laryngeal carcinoma Hep-2 cell line in vitro, Hep-2 cells cultured in vitro were treated with different concentrations of DRB. Changes in cell proliferation, apoptotic rate and invasiveness were detected by MTT assay, flow cytometry (FCM) and matrigel in vitro invasion assay, respectively. It was found that DRB inhibited the proliferation of Hep-2 cells in a dose- and time-dependent manner. After being treated with 0, 10, 20, 40, 80 μmmol/L DRB for 24 h, the apoptotic rate in Hep-2 cells was (0.68±0.19)%, (1.95±0.12)%, (8.51±0.26)%, (11.26±0.17)% and (14.99±0.32)%, respectively. The matrigel in vitro invasion assay revealed that DRB began to inhibit the invasion of Hep-2 cells at the concentration of 5 μmmol/L, and with the increase of DRB concentration, the inhibitory effect was enhanced. It was suggested that DRB could influence the essential biological characteristics of Hep-2 cells, inhibit Hep-2 cells proliferation, reduce invasive ability and induce apoptosis of Hep-2 cells. 展开更多
关键词 protein-serine-threonine kinases 5 6-Dichloro-1-β-D-ribofuranosyl- benzimidazole laryngeal neoplasms Hep-2 cell line
下载PDF
Relation between Starlight and Nebular Emission Lines of Star-Forming Galaxies
11
作者 Hong-LinLu Hong-YanZhou +4 位作者 Ting-GuiWang Zhen-QuanZhuang Xiao-BoDong Jun-XianWang ChengLi 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2005年第3期221-228,共8页
We present an exercise that intends to establish a relationship between the strength of nebular emission lines and optical stellar features in the spectrum of a galaxy. After accurately subtracting the stellar continu... We present an exercise that intends to establish a relationship between the strength of nebular emission lines and optical stellar features in the spectrum of a galaxy. After accurately subtracting the stellar continuum and the underlying stellar absorption, we made reliable measurements of the emission lines of all the galaxies in the Sloan Digital Sky Survey Data Release 2 (SDSS DR2). More than 4000 star-forming galaxies with high S/N ratio of both the stellar spectrum and the emission lines are selected. These galaxy spectra are fitted with the 10 PCs of Yip et al., after all the emission line regions have been filtered out. We find that the flux of hydrogen Balmer emission lines, Ha and Hβ can be well recovered from the PCs, while the metal lines are not well reproduced. The fluxes of Ha and Hβ measured from the PC-reconstructed spectra and from the observed spectra agree well with an rms scatter of only - 0.1 dex. This result suggests that, with moderate spectral resolution and S/N ratio, the optical stellar spectrum of a galaxy can serve as an indicator of star formation rate. 展开更多
关键词 galaxies: fundamental parameters - galaxies: starburst - radiation: lines CONTINUUM
下载PDF
SMA molecular line survey towards the massive star-forming region G10.6-0.4in W31complex
12
作者 Wai-Ho Wong Tao An 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第11期29-42,共14页
Line surveys of complex molecules with millimeter and sub-millimeter telescopes are important for probing the physical and chemical environments of massive star forming regions(MSFRs).We present a molecular line surve... Line surveys of complex molecules with millimeter and sub-millimeter telescopes are important for probing the physical and chemical environments of massive star forming regions(MSFRs).We present a molecular line survey with the Submillimeter Array(SMA) in the frequency ranges of 220.3–222.3 GHz and 230.3–232.3 GHz toward G10.6-0.4, the brightest star forming core in the W31 complex. Ninety-nine transitions from 22 molecular species and their isotopologues are identified. The moment 0 images of typical molecules show a compact core which is concentrated at the continuum peak position. Based on the local thermodynamic equilibrium assumption, the molecular line data are modeled. The rotational temperatures of those molecular species range from 96 to 178 K and their column densities range from 2.0×1014to 3.7×1017cm-2. The observational data suggest that all complex molecules are located in a warm environment. Chemical environments of the molecules are discussed. We compared molecular abundances and gas temperatures in G10.6-0.4 with those in other MSFRs, and found that gas temperatures and fractional abundances of specific molecules in G10.6-0.4 are similar to the typical MSFR W51 North, suggesting that there are similar physical and chemical environments in these two MSFRs. 展开更多
关键词 stars: formation ISM: abundances ISM: individual objects: G10.6-0.4 ISM: molecules radio lines: ISM
下载PDF
Effects of 4-(3-Chloro-Benzyl)-6,7-Dimethoxy-Quinazoline on Kinetics of P120-Catenin and Periplakin in Human Buccal Mucosa Squamous Carcinoma Cell Line
13
作者 Isao Tamura Aiko Kamada +3 位作者 Seiji Goda Yoshihiro Yoshikawa Eisuke Domae Takashi Ikeo 《Open Journal of Stomatology》 2014年第5期249-257,共9页
In order to detect molecular markers for the epidermal growth factor inhibitor 4-(3-chloro-benzyl)- 6,7-dimethoxy-quinazoline (tyrphostin), we investigated the kinetics of p120-catenin and periplakin in the human bucc... In order to detect molecular markers for the epidermal growth factor inhibitor 4-(3-chloro-benzyl)- 6,7-dimethoxy-quinazoline (tyrphostin), we investigated the kinetics of p120-catenin and periplakin in the human buccal mucosa squamous cancer cell line BICR 10 treated with 3 nM tyrphostin. Growth of BICR 10 cells was inhibited by treatment with tyrphostin. Although changes were not observed in the expression of EGFR and p120-catenin, expression of Akt, Src and periplakin in BICR 10 treated with 3 nM tyrphostin tended to decrease. In addition, phosphorylation of EGFR, Akt and Src was inhibited by treatment with tyrphostin. On immunocytochemical staining, immunoreactions with phosphorylated EGFR, phosphorylated Akt and phosphorylated p120-catenin were weak in BICR 10 treated with tyrphostin. There was a slight immunocy to chemical reaction to periplakin in BICR 10 cells induced by tyrphostin. In conclusion, the decrease in phosphorylation in EGFR and p120-catenin by tyrphostin, following the decrease in Src or Akt phosphorylation, may inhibit expression of several growth factors associated with the proliferation and migration of cancer cells. 展开更多
关键词 4-(3-Chloro-Benzyl)-6 7-Dimethoxy-Quinazoline HUMAN Buccal Mucosa Squamous Cancer Cell line P120-CATENIN Periplakin
下载PDF
Relation between the “Double-Hump” Behavior in the Radio Band and the Broad-Line Luminosity for Blazars
14
作者 Zhao-Hua Xie Hong Dai +2 位作者 Jian-Ming Hao Lei-Ming Du Xiong Zhang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第2期209-214,共6页
The physics behind the spectral energy distribution (SED) of blazars remains open. We assembled 36 blazars to tackle the factors that control their SED. Now, many blazar spectra have the "double hump" feature in t... The physics behind the spectral energy distribution (SED) of blazars remains open. We assembled 36 blazars to tackle the factors that control their SED. Now, many blazar spectra have the "double hump" feature in the radio and far-IR frequencies. For these a parameter, △, is created to characterize the behavior of the SED. We found a significant correlation between the broad-line luminosity (LBLR) and △. Because L BLR is an indicator of the accreting power of the source in blazars, we derived a linear correlation, △ oc M1/3.18, which suggests that the SED of blazars may depend on the accretion rate, like that of BL Lac objects. We also found a significant correlation between m and △ for a sample of 11 blazars (out of one of 36) with available black hole masses. This implies the Eddington accretion ratio may influence the shape of the SED of blazars. 展开更多
关键词 accretion accretion disks - black hole physics - galaxies active - galaxies emission lines - galaxies nuclei
下载PDF
Relations between the IR-UV-X-ray Continuum and Emission Lines for a Large Composite Sample of Narrow Line and Normal Seyfert 1 Galaxies
15
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
下载PDF
SDSS J143030.22-001115.1: A Misclassified Narrow-line Seyfert 1 Galaxy with Flat X-ray Spectrum
16
作者 Wei-Hao Bian Quan-Ling Cui Li-Hua Chao 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第3期281-286,共6页
We used multi-component profiles to model the HE and [O Ⅲ]λλ4959,5007 lines of SDSS J143030.22-001115.1, a narrow-line Seyfert 1 galaxy (NLS1) in a sample of 150 NLS1 candidates selected from the Sloan Digital Sk... We used multi-component profiles to model the HE and [O Ⅲ]λλ4959,5007 lines of SDSS J143030.22-001115.1, a narrow-line Seyfert 1 galaxy (NLS1) in a sample of 150 NLS1 candidates selected from the Sloan Digital Sky Survey (SDSS), Early Data Release (EDR). After subtracting the HE contribution from narrow line regions (NLRs), we found that its full width half maximum (FWHM) of broad H/3 line is nearly 2900km s^-1, significantly larger than the customarily adopted criterion of 2000 km s^-1. With its weak Fe II multiples, we believe that SDSS J143030.22-001115.1 should not be classified as a genuine NLS1. When we calculate the virial black hole masses of NLSls, we should use the Hβ linewidth after subtracting the NLR component. 展开更多
关键词 galaxies: active - galaxies: emission lines - galaxies: nuclei - galaxies:Seyfert- galaxies:individual: J143030.22-001115.1
下载PDF
Correcting the Contamination of Second-order Spectra:Improving HαMeasurements in Reverberation Mapping Campaigns
17
作者 Wen-Zhe Xi Kai-Xing Lu +5 位作者 Hai-Cheng Feng Sha-Sha Li Jin-Ming Bai Rui-Lei Zhou Hong-Tao Liu Jian-Guo Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第12期242-251,共10页
Long-term spectroscopic monitoring campaigns on active galactic nuclei(AGNs)provide a wealth of information about its interior structure and kinematics.However,a number of the observations suffer from the contaminatio... Long-term spectroscopic monitoring campaigns on active galactic nuclei(AGNs)provide a wealth of information about its interior structure and kinematics.However,a number of the observations suffer from the contamination of second-order spectra(SOS)which will introduce some undesirable uncertainties at the red side of the spectra.In this paper,we test the effect of SOS and propose a method to correct it in the time domain spectroscopic data using the simultaneously observed comparison stars.Based on the reverberation mapping(RM)data of NGC 5548 in2019,one of the most intensively monitored AGNs by the Lijiang 2.4 m telescope,we find that the scientific object,comparison star,and spectrophotometric standard star can jointly introduce up to~30%SOS for Grism 14.This irregular but smooth SOS significantly affects the flux density and profile of the emission line,while having little effect on the light curve.After applying our method to each spectrum,we find that the SOS can be corrected effectively.The deviation between corrected and intrinsic spectra is~2%,and the impact of SOS on time lag is very minor.This method makes it possible to obtain the HαRM measurements from archival data provided that the spectral shape of the AGN under investigation does not have a large change. 展开更多
关键词 techniques spectroscopic-methods data analysis-galaxies individual(NGC 5548)-(galaxies:)quasars emission lines
下载PDF
基于MI-BCI的上肢在线运动康复原型系统 被引量:7
18
作者 李明爱 罗新勇 +1 位作者 崔燕 杨金福 《北京生物医学工程》 2017年第3期273-278,共6页
目的为实现单侧肢体运动想象与实际运动康复的身体部位及运动模式的一致化,进一步改善康复效果,本文设计了一种基于MI-BCI的上肢在线运动功能康复原型系统。方法该系统主要包括以g.MOBIlab脑电仪为核心的运动想象脑电信号(motor imagery... 目的为实现单侧肢体运动想象与实际运动康复的身体部位及运动模式的一致化,进一步改善康复效果,本文设计了一种基于MI-BCI的上肢在线运动功能康复原型系统。方法该系统主要包括以g.MOBIlab脑电仪为核心的运动想象脑电信号(motor imagery electroencephalogram,MI-EEG)实时采集模块、在线处理模块及机械手臂控制模块等几部分。利用MATLAB和C语言混合编程及多线程技术完成对MI-EEG的实时采集、眼电伪迹去除、特征提取与分类,基于ARM9的S3C2440A微处理器设计机械手臂控制系统,控制模块与PC机间采用基于请求响应模式的通信协议,用手臂伸/屈MI-EEG的分类结果实现对机械手臂伸/屈同运动模式的实时控制。结果对5名受试者进行实际测试,对手臂伸/屈MI-EEG的平均识别率为76.75%,验证了系统的实用性。结论本系统具有良好的自适应性和实时性,为研制出更加自然、可临床应用的上肢运动康复系统奠定了基础。 展开更多
关键词 运动想象脑电信号 上肢 在线康复 脑机接口 原型系统
下载PDF
月球卫星CE-1三线阵影像数据的解算试验 被引量:2
19
作者 王涛 项琳 曹锋 《遥感信息》 CSCD 2010年第3期18-20,25,共4页
利用"嫦娥一号"卫星上搭载的CCD立体相机获取的月面三线阵影像数据,再配合激光高度计(LAM)数据,经过摄影测量解算可以制作月面数字高程模型(DEM)和数字正射影像图(DOM)。本文采用两种方法对月球卫星CE-1三线阵影像数据进行了... 利用"嫦娥一号"卫星上搭载的CCD立体相机获取的月面三线阵影像数据,再配合激光高度计(LAM)数据,经过摄影测量解算可以制作月面数字高程模型(DEM)和数字正射影像图(DOM)。本文采用两种方法对月球卫星CE-1三线阵影像数据进行了月面点坐标的解算试验,方法一是根据测控给出的外方位元素直接解算,方法二是对影像上提取的像点进行区域网平差解算,根据两种方法的解算结果,比较了各方法的精度,达到了预期目的。 展开更多
关键词 “嫦娥一号”卫星 月球 三线阵影像 区域网平差
下载PDF
Study on the method of optimal location on explosion events at near-source site 被引量:2
20
作者 LI Xue-zheng 《Acta Seismologica Sinica(English Edition)》 CSCD 2001年第3期349-355,共7页
IntroductionEarthquake location is one of the inverse problems in seismology. The accurate earthquake source location is the basis of studies of earthquake images, the relation analysis between seismicity and tectonic... IntroductionEarthquake location is one of the inverse problems in seismology. The accurate earthquake source location is the basis of studies of earthquake images, the relation analysis between seismicity and tectonics, and the important parameters of earthquakes. It is also the basic data used to study the space distribution of aftershocks after a strong earthquake. The earthquake location accuracy mainly depends on reliability of the velocity models for the earth¢s crust, the reasonable design of the seismograph network, the accuracy of arrival time, and the location method used (ZHAO, 1983; ZHU, ZHAO, 1997; LI, et al, 1999). The reliability of the velocity model directly influences loca-tion results. The reasonable seismograph network design can improve the location accuracy; otherwise it will in-troduce ill-conditioned equations and large location error. If arrival time is not accurate, for example, if the seismic phase is wrongly identified or the time service is inaccurate, large arrival time error will be produced, and the location results and real hypocenters will be discordant. Different location algorithms adopted will produce differ-ent location errors. The residual criterion chosen has influence on location results. Besides, whether the event is correctly associated also influences the location quality. In practice, it can often be seen that large location devia-tion introduced by wrong event association. 展开更多
关键词 explosion EARTHQUAKES EARTHQUAKE location SIMPLEX PEDAL point on RADIAL line 文章编号:1000-9116(2001)02-0349-07
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部