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Simultaneous optical g, r, i monitoring and IDV periodic analysis for quasar 3C 454.3

Research in Astronomy and Astrophysics 2019年第10期19卷 43-50页

作者： Jun-hui fan Yu-Hai Yuan Hong Wu feng Wang Jun Tao Min-feng Gu Center for Astrophysics Guangzhou University Guangzhou 510006 China Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province Guangzhou 510006 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100101 China Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China

With the 1.26 m National Astronomical Observatory-Guangzhou University Infrared/Optical Telescope(NAGIOT) at Xinglong Station of National Astronomical Observatories, Chinese Academy of Sciences, we obtained 419 groups of simultaneous observations at g, r and i bands, for the first time,targeting quasar 3 C 454.3 during 15 nights from 2016 October 23 to 2016 December 15. Based on our observations, we investigate the optical variabilities, the relation between brightness and color index, and the periodicity variability. The presented analyses demonstrate that: 1. The maximum variations at the g, r and i bands are △mg|max= 1.015 ± 0.042 mag,△mr|max= 1.188 ± 0.050 mag and △mi|max= 1.305 ± 0.057 mag respectively. 2. During our 15 night monitoring program, intra-day variability was detected on one night(Nov. 2). Also, the brightness increased by A = 15.86% over 50.8 min,then decreased by A = 22.42% over 40.1 min. After a small bright state, its brightness increased again by18.1% over 55 min at the g band. Similar phenomena happened at r and i bands. The intra-day variabilities at the three bands on 2016 November 2 indicate a period of 105 min, which implies a black hole mass of MBH =(0.3 ~ 1.85)× 10^9 M⊙. 3. There is an anti-correlation between color index and magnitude,suggesting the source becomes redder when it brightens.

关键词： galaxies quasars individual (3C 454.3)

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Evolution of isolated G-band bright points: size, intensity and velocity

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Research in Astronomy and Astrophysics 2014年第6期14卷 741-752页

作者： Yun-Fei Yang Jia-Ben Lin Song feng Kai-fan Ji hui Deng feng Wang Faculty of Information Engineering and Automation/Yunnan Key Laboratory of Computer Technology Application Kunming University of Science and Technology Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Modern Astronomy and Astrophysics Nanjing University Ministry of Education

We study the evolution pattern of isolated G-band bright points （GBPs） in terms of their size, intensity and velocity. Using a high resolution image sequence taken with the Hinode/Solar Optical Telescope （SOT）, we detect GBPs in each image by the Laplacian and Morphological Dilation algorithm, and track their evolutions by a 26-adjacent method in a three-dimensional space-time cube. For quantifying the evolution, we propose a quantification method based on lifetime normalization which aligns the different lifetimes to common stages. The quantification results show that, on average, the diameter of isolated GBPs changes from 166 to 173 km, then down to 165 km; the maximum intensity contrast changes from 1.012 to 1.027, then down to 1.011; however, the velocity changes from 1.709 to 1.593 km s-1, then up to 1.703 km s-i. The results indicate that the evolution follows a pattern such that the GBP is small, faint and fast-moving at the birth stage, becomes big, bright and slow-moving at the middle stage, then gets small, faint and fast-moving at the decay stage until disappearance. Although the differences are very small, a two-sample t-test is used to demonstrate there are significant differences in means between the distri- butions of the different stages. Furthermore, we quantify the relationship between the lifetimes of GBPs and their properties. It is found that there are positive correlations between the lifetimes and their sizes and intensities with correlation coefficients of 0.83 and 0.65, respectively; however, there is a negative correlation between the life- times and velocities with a correlation coefficient of-0.49. In summary, the longer the GBP persists, the bigger, brighter and slower it will be.

关键词： techniques: image processing -- Sun: photosphere -- methods: dataanalysis -- methods: statistical

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Modal Parameter Identification Method of Jacket Platform Structure Based on AFDD and Optimized FBFFT

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China Ocean Engineering 2023年第3期37卷 393-407页

作者： LENG Jian-cheng MA Jin-yong fan Zong-heng QIAN Wan-dong feng hui-yu School of Mechanical Science and Engineering Northeast Petroleum UniversityDaqing 163318China

Offshore platforms are susceptible to structural damage due to prolonged exposure to random loads,such as wind,waves,and *** is particularly true for platforms that have been in service for an extended *** the modal parameters of offshore platforms is crucial for damage diagno sis,as it serves as a prerequisite and foundation for the ***,it holds great significance to prioritize the identification of these *** at the shortcomings of the traditional Fast Bayesian Fast Fourier Transform(FBFFT) method,this paper proposes a modal parameter identification method based on Automatic Frequency Domain Decomposition(AFDD) and optimized *** introducing the AFDD method and Powell optimization algorithm,this method can automatically identify the initial value of natural frequency and solve the objective function efficiently and *** order to verify the feasibility and effectiveness of the proposed method,it is used to identify the modal parameters of the IASC-ASCE benchmark model and the j acket platform structure model,and the Most Probable Value(MPV) of the modal parameters and their respective posterior uncertainties are successfully *** identification results of the IASC-ASCE benc hmark model are compared with the identification re sults of the MODE-ID method,which verifies the effectivene ss and accuracy of the proposed method for identifying modal *** provides a simple and feasible method for quantifying the influence of uncertain factors such as environmental parameters on the identification results,and also provide s a reference for modal parameter identification of other large structures.

关键词： jacket platform uncertain modal parameter identification FBFFT method environmental excitation AFDD method Powell optimization

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SDSS spectroscopy for blazars in the Fermi LAT bright AGN sample

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Research in Astronomy and Astrophysics 2009年第11期9卷 1192-1204页

作者： Zhao-Yu Chen Min-feng Gu Zhong-hui fan Xin-Wu Cao Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of Sciences Shanghai 200030 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Physics Yunnan University Kunming 650091 China

We have collected all available spectra and photometric data from the SDSS catalog for bright AGNs complied from the first three months of the Fermi large area telescope all-sky survey. Based on the 106 high-confidence and 11 low-confidence associated bright AGN list, the photometry data are collected from SDSS DR7 for 28 sources （12 BL Lacs and 16 FSRQs）, two of which are low-confidence associated bright AGNs. Among these 28 SDSS photometric sources, SDSS spectra are available for 20 sources （6 BL Lacs and 14 FSRQs）. The black hole masses MBH and the broad line region （BLR） luminosity were obtained for 14 FSRQs by measuring the line-widths and strengths of broad emission lines from the SDSS spectra. The broad emission line measurements of five FSRQs are presented for the first time in this work. The optical continuum emission of these 14 FSRQs is found to be likely dominated by the non-thermal jet emission by comparing the relationship between the broad Mg II line and continuum luminosity to that of radio-quiet AGNs. The black hole mass of the 14 FSRQs ranges from 10^8.2 M⊙ to 10^9.9 M⊙, with most of the sources larger than 10^9 M⊙. The Eddington ratio Lbol/LEdd ranges from 10-1＇5 to - 1. This implies that an optically thin, geometrically thick accretion disk may exist in these FSRQs.

关键词： galaxies active -- galaxies nuclei -- gamma rays observations -- quasars emission lines -- BL Lacertae objects general

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Synthesis of 5-vinyl-2-norbornene through Diels-Alder reaction of cyclopentadiene with 1,3-butadiene in supercritical carbon dioxide

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Chinese Chemical Letters 2017年第4期28卷 900-904页

作者： fan-Qiang Meng Xiu-Juan feng Wan-hui Wang Ming Bao State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116023 China School of Petroleum and Chemical Engineering Dalian University of Technology Panjin 124221 China

An efficient method for the synthesis of 5-vinyl-2-norbornene from cyclopentadiene and 1,3-butadiene was *** Diels-Alder reaction of cyclopentadiene with 1,3-butadiene proceeded smoothly in supercritical carbon dioxide in the absence of any polymerization inhibitor to produce the corresponding5-vinyl-2-norbornene in satisfactory yield with high selectivity.

关键词： 5-Vinyl-2-norbornene Diels-Alder reaction Cyclopentadiene 1 3-Butadiene Supercritical carbon dioxide

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Simultaneous Determination of Two Types of Active Components with Different Physicochemical Properties in Kushen by HPLC-UV

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Chemical Research in Chinese Universities 2011年第3期27卷 375-379页

作者： ZHANG Yu-feng ZHAO Qin-qin SHAO Qin fan Xiao-hui Department of Chinese Medicine Science&Engineering Zhejiang UniversityHangzhou 310058P.R.China

A simple, reliable and accurate high performance liquid chromatography(HPLC) coupled with a UV detector at varied wavelength was developed for the quantitation of two types of anti-carcinogenic compounds, namely, Kushen alkaloids(KS-As) and Kushen flavonoids(KS-Fs), in Kushen. Their remarkable difference in physicochemical properties was circumvented by integrated optimization of column and mobile phase. The separation was achieved on an alkaline-resisting C18 column via gradient elution with acetonitrile(ACN) and 0.025%(volume ratio) diethylamine(DEA) in water as mobile phase. The flow rate was 0.7 mL/min, and the column temperature was maintained at 35 °C. UV detection wavelength was set at 225 nm to monitor KS-As, and then changed to 335 nm for KS-Fs at 26th min, which was kept for 30 min before returning to the original wavelength. All the calibration curves show good linearity(r20.999) within test ranges. The intra- and inter-day precision values of these components were less than 3.82%, and the average recovery rates obtained were in a range of 97.24%―102.64% for all the samples with RSD below 3.94%. This assay was successfully applied to determining the major active components in commercial herbal samples of Kushen. Moreover, the possible relationship between sample and the geographical region was visualized based on the contents of the 6 compounds in the light of principal component analysis(PCA). The results suggest that the proposed method facilitates the quality control of Kushen.

关键词： Column liquid chromatography Sophora flavescen Kushen alkaloid Kushen flavonoid

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Effect of cooling temperature on the microstructure and corrosion behavior of X80 pipeline steel

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International Journal of Minerals,Metallurgy and Materials 2020年第3期27卷 347-353页

作者： Jing Ma fan feng Bai-qing Yu Hai-feng Chen Li-feng fan School of Materials Hebei University of Science and TechnologyShijiazhuang 050018China Hebei Key Laboratory of Material Near-Net Forming Technology Shijiazhuang 050018China School of Transportation Inner Mongolia UniversityHohhot 010070China

Dual-phase accelerated cooling(DPAC) was applied to X80 pipeline steel to obtain its microstructure with different amounts of bainite and ferrite. The microstructure, hardness, and polarization behaviors of the steel, cooled to different temperatures, were investigated. Results showed that, with decreasing cooling temperature, the amount of polygon ferrite(PF) increased while that of acicular ferrite(AF) decreased. The amount of bainite correspondingly decreased, except when cooled to 760°C. Moreover, the grain size of ferrite increased. The corrosion behaviors of different phases were distinct. Martensite/austenite(M/A) islands presented at the grain boundary of the PF phase caused small pits. Numerous micro-corrosion cells were formed in the AF and bainite phases, where micropores were prone to form. X80 pipeline steel cooled to 700°C had the best corrosion resistance in the simulated seawater. The decreased amount of the PF phase reduced the area of cathode, resulting in slight corrosion. About 40 vol% of the bainite phase provided strength while the PF phase provided adequate ductility to the X80 steel. It was concluded that the appropriate cooling temperature was 700°C for ideal corrosion resistance and mechanical properties.

关键词： X80 pipeline steel Dual-phase accelerated cooling microstructure corrosion behavior

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Computing knots by quadratic and cubic polynomial curves

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Computational Visual Media 2020年第4期6卷 417-430页

作者： fan Zhang Jinjiang Li Peiqiang Liu hui fan School of Computer Science and Technology Shandong Technology and Business UniversityYantai 264005China Co-Innovation Center of Shandong Colleges and Universities:Future Intelligent Computing Yantai 264005China

A new method is presented to determine parameter values(knot)for data points for curve and surface *** four adjacent data points,a quadratic polynomial curve can be determined uniquely if the four points form a convex *** the four data points do not form a convex polygon,a cubic polynomial curve with one degree of freedom is used to interpolate the four points,so that the interpolant has better shape,approximating the polygon formed by the four data *** degree of freedom is determined by minimizing the cubic coefficient of the cubic polynomial *** advantages of the new method are,firstly,the knots computed have quadratic polynomial precision,i.e.,if the data points are sampled from a quadratic polynomial curve,and the knots are used to construct a quadratic polynomial,it reproduces the original quadratic ***,the new method is affine invariant,which is significant,as most parameterization methods do not have this ***,it computes knots using a local *** show that curves constructed using knots computed by the new method have better interpolation precision than for existing methods.

关键词： knot interpolation polynomial curve affine invariant

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Dynamic Regulation of Hydrogen Bonding Networks and Solvation Structures for Synergistic Solar‑Thermal Desalination of Seawater and Catalytic Degradation of Organic Pollutants

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Nano-Micro Letters 2025年第2期17卷 548-565页

作者： Ming‑Yuan Yu Jing Wu Guang Yin fan‑Zhen Jiao Zhong‑Zhen Yu Jin Qu Beijing Key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

Although solar steam generation strategy is efficient in desalinating seawater,it is still challenging to achieve continuous solar-thermal desalination of seawater and catalytic degradation of organic ***,dynamic regulations of hydrogen bonding networks and solvation structures are realized by designing an asymmetric bilayer membrane consisting of a bacterial cellulose/carbon nanotube/Co_(2)(OH)_(2)CO_(3)nanorod top layer and a bacterial cellulose/Co_(2)(OH)_(2)CO_(3)nanorod(BCH)bottom ***,the hydrogen bonding networks inside the membrane can be tuned by the rich surface–OH groups of the bacterial cellulose and Co_(2)(OH)_(2)CO_(3)as well as the ions and radicals in situ generated during the catalysis ***,both SO_(4)^(2−)and HSO_(5)−can regulate the solvation structure of Na^(+)and be adsorbed more preferentially on the evaporation surface than Cl^(−),thus hindering the de-solvation of the solvated Na^(+)and subsequent nucleation/growth of ***,the heat generated by the solar-thermal energy conversion can accelerate the reaction kinetics and enhance the catalytic degradation *** work provides a flow-bed water purification system with an asymmetric solar-thermal and catalytic membrane for synergistic solar thermal desalination of seawater/brine and catalytic degradation of organic pollutants.

关键词： Solar steam generation Seawater desalination Catalytic degradation Bacterial cellulose Cobalt hydroxycarbonate nanorods

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Development of sandwich joining piece to fabricate segmented half-Heusler/skutterudite thermoelectric joints

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Rare Metals 2021年第7期40卷 1966-1970页

作者： Wei-An Wang Xiao-Ya Li Yun-Fei Xing Ming Gu Long-hui fang Ye-feng Bao Jin-hui fan School of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022China The State Key Lab of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China School of Mechanical Engineering Donghua UniversityShanghai 201620China

Sn/Ni-Sn/Sn sandwich joining piece was developed and applied to fabricate segmented half-Heusler/skutterudite thermoelectric joints,and high-temperature service behavior of the joints was *** microstructure and contact resistance of the joint before and after aging were *** joints are well bonded and no cracks appear at the interfaces of the joint before and after aging,which can be attributed to the formation of high-melting point intermetallic *** electrical resistance crosses the joining layer smoothly and the contact resistance is *** results show that the sandwich joining piece is effective and flexible,and promising for the preparation of segmented thermoelectric devices.

关键词： Sandwich joining piece Segmented thermoelectric joint Microstructure Contact resistance

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