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Timing and Spectral Analysis of the Black Hole X-Ray Binary MAXI J1803-298 with Insight-HXMT Data

Research in Astronomy and Astrophysics 2024年第6期24卷 209-224页

作者： ying-chen xu Jin-Lu Qu MMéndez Rui-Can Ma Long Ji Liang Zhang Yue Huang Qing-Cui Bu Li-Ming Song Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Kapteyn Astronomical Institute University of GroningenP.O.BOX 8009700 AV GroningenThe Netherlands Dongguan Neutron Science Center Dongguan 523808China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls UniversitätSand 1D-72076 TübingenGermany

We present a comprehensive analysis of the 2021 outburst of MAXI J1803–298 utilizing observations of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT)spanning from the low hard state to the high soft *** the Insight-HXMT data set,compared to the previous work,we identify a more prolonged presence of typeC quasi-periodic oscillations(QPOs)with centroid frequencies ranging from~0.16 to 6.3 Hz,which present correlations with the hardness ratio and the photon index of the Comptonized *** QPO frequencies less than~2 Hz,the QPO phase lags are hard(photons of 10–19 keV arrive later than those of 1–4 keV),while at higher frequencies,the lags become soft at and above~4 ***,the spectra in all Insight-HXMT observations consist of a multi-color blackbody component and a Comptonized component,as commonly observed in classical black hole X-ray *** analyze state transitions and the evolution of accretion geometry in this *** fitted inner disk radius increases abnormally during the low hard state,hypothesized to result from the corona condensing onto the inner ***,two significant drops in flux are observed during the soft intermediate state,maybe implying changes in the corona/jet and the disk,respectively.

关键词： X-rays:binaries accretion accretion disks stars:black holes

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Temporal and Spectral Characteristics of Persistent Emission and Special Bursts of Magnetar SGR J1935+2154 Based on Insight-HXMT

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Research in Astronomy and Astrophysics 2024年第6期24卷 225-233页

作者： xue-Feng Lu Li-Ming Song Ming-Yu Ge Shuang-Nan Zhang Jin-Lu Qu Ce Cai Cong-Zhan Liu cheng-Kui Li Yu-Cong Fu ying-chen xu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China College of Physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal UniversityShijiazhuang 050024China Department of Astronomy Beijing Normal UniversityBeijing 100875China

In October 2022,the magnetar SGR J1935+2154 entered the active outburst *** the episode,the InsightHXMT satellite carried out a long observation that lasted for 20 *** than 300 bursts were detected,and a certain amount of persistent radiation signals were also *** paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT *** the same time,the burst phase distribution characteristics,spectral lag results of burst,the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are *** found that there is no significant delay feature during different energy bands for the bursts of SGR J1935+*** observed zero-lag burst does not have a unique *** time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the *** also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.

关键词： radiation mechanisms:general dense matter magnetic fields

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Characterization of Phenol Biodegradation by Comamonas testosteroni ZD4-1 and Pseudomonas aeruginosa ZD4-3

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Biomedical and Environmental Sciences 2003年第2期16卷 163-172页

作者： ying-xu chen HE LIU HUA-LIN chen Department of Environmental Engineering Zhejiang UniversityHangzhou 310029China

To investigate the characteristic and biochemical mechanism about the phenol biodegradation by bacterial strains ZD 4-1 and ZD 4-3. Methods Bacterial strains ZD 4-1 and ZD 4-3 were isolated by using phenol as the sole source of carbon and energy, and identified by 16S rDNA sequence analysis. The concentrations of phenol and total organic carbon (TOC) were monitored to explore the degradation mechanism. The biodegradation intermediates were scanned at 375 nm by using a uv-vis spectrophotometer. The enzyme assays were performed to detect the activities of dioxygenases. Results Bacterial strains ZD 4-1 and ZD 4-3 were identified as Comamonas testosteroni and Pseudomonas aeruginosa by 16S rDNA sequence analysis, respectively. The growth of the two strains was observed on a variety of aromatic hydrocarbons. The strains ZD 4-1 and ZD 4-3 metabolized phenol via ortho-pathways and meta-pathways, respectively. In addition, the results of enzyme assays showed that the biodegradation efficiency of phenol by meta-pathways was higher than that by ortho-pathways. Finally, the results of induction experiment indicated that the catechol dioxygenases, both catechol 1,2-dioxygenase (C12O) and catechol 2,3-dioxygenase (C23O), were all inducible. Conclusion The strains ZD 4-1 and ZD 4-3 metabolize phenol through ortho-pathways and meta-pathway, respectively. Furthermore, the biodegradation efficiency of phenol by meta-pathways is higher than that by ortho-pathways.

关键词： Aromatic compounds Phenol Biodegradation Ortho-pathways Meta-pathways C12O C23O

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Depolymerization of Poly(bisphenol A carbonate) in Subcritical and Supercritical Toluene

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Chinese Chemical Letters 2006年第4期17卷 545-548页

作者： Zhi Yan PAN Zhen BAO ying xu chen Department of Environmental Engineering Zhejiang University Hangzhou 310027 College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310032

The depolymerization of poly（bisphenol A carbonate）（PC） in subcritical and supercritical toluene was studied. The experimental parameters, which influence the depolymerization reaction such as temperature （570-633 K）, pressure （4.0-7.0 MPa）, reaction time （5-60 min）, and toluene to PC weight ratio （3.0-11.0）, were investigated, and the reaction products were determined by CrC, GC/MS and FT-IR spectrometer. It was found that the main product of the depolymerization reaction was bisphenol A（BPA）. BPA accounted for over 55.7% of the depolymerization products at reaction temperature 613 K, pressure 5.0-6.0 MPa, reaction time 15 min and toluene/PC weight ratio of around 7.0.

关键词： Depolymerization poly(bisphenol A carbonate) supercritical toluene.

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Effects of 60-day NO_2 fumigation on growth,oxidative stress and antioxidative response in Cinnamomum camphora seedlings

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第3期11卷 190-199页

作者： Zhuo-mei chen ying-xu chen Guo-jian DU Xi-lin WU Feng LI College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 China Zhejiang Forestry Academy Hangzhou 310023 China Department of Geography Minjiang University Fuzhou 350108 China

Objective： To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide （NO2） fumigation. Methods： Measurements were made up of the growth, chlorophyll content, chlorophyll fluorescence, antioxidant system and lipid peroxidation of one-year-old C. camphora seedlings exposed to NO2 （0.1, 0.5, and 4 μl/L） fumigation in open top chambers over a period of 60 d. Results： After the first 30 d, 0.5 and 4.0 μl/L NO2 showed insignificant effects on the growth of C. camphora seedlings. However, exposure to 0.5 and 4.0 pilL NO2 for 15 d significantly reduced their chlorophyll content （P〈0.05）, enhanced their malondialdehyde （MDA） content and superoxide dismutase （SOD） activity （P〈0.05）, and also significantly reduced the maximal quantum yield of PSII in the dark [the ratio of variable fluorescence to maximal fluorescence （Fv/Fm）] （P〈0.05）. In the latter 30 d, 0.5μl/L NO2 showed a positive effect on the vitality of the seedlings, which was reflected by a recovery in the ratio of Fv/Fm and chlorophyll content, and obviously enhanced growth, SOD activity, ascorbate （AsA） content and glutathione reductase （GR） activity （P〈0.05）; 4.0 pilL NO2 then showed a negative effect, indicated by significant reductions in chlorophyll content and the ratio of Fv/Fm, and inhibited growth （P〈0.05）. Conclusion： The results suggest adaptation of C. camphora seedlings to 60-d exposure to 0.1 and 0.5 μl/L NO2, but not to 60-d exposure to 4.0 pilL NO2 C. camphora seedlings may protect themselves from injury by strengthening their antioxidant system in response to NO2-induced oxidative stress.

关键词： Cinnamomum camphora Fumigation Growth Chlorophyll content Chlorophyll fluorescence Antioxidant Lipid peroxidation

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Protein Changes in Response to Pyrene Stress in Maize （Zea mays L.） Leaves

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Journal of Integrative Plant Biology 2007年第2期49卷 187-195页

作者： Sheng-You xu ying-xu chen Wei-Xiang Wu Shao-Jian Zheng Sheng-Guo xue Shi-ying Yang Yi-Jin Peng Department of Environmental Engineering Zhejiang University Hangzhou 310029 China Department of Resource and Environment Huangshan University Huangshan 245000 China College of Environmental Science and Engineering Ocean University of China Qingdao 266003 China

Phytoremedlation is a relatively new approach to remove polycyclic aromatic hydrocarbons （PAHs） from the environment. When plants are grown under pyrene treatment, they respond by synthesizing a set of protective proteins. To learn more about protein changes in response to pyrene treatment, we extracted total proteins from the leaves of maize （Zea mays L.） 1 week after pyrene treatment. The proteins extracted were separated with twodimensional gel electrophoresis. In total, approximately 54 protein spots were found by comparing gels from treated and control groups. According to the Isoelectric point, molecular weight, and abundance of these protein spots, 20 pyrene-lnduced proteins were found to have changed abundance. Of these, 15 protein spots were Increased and five protein spots were newly appeared in pyrene-treated plant leaves. Six model upregulated protein spots of different molecular weights were excised from the gels and subjected to trypsin digestion followed by peptide separation using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Peptlde masses were used to search the matrix-science database for protein Identification. Two of the proteins were Identified on the basis of the homology of their peptide profiles with existing protein sequences as pyruvate orthophosphate diklnase and the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunlt. These proteins are Involved in the regulation of carbohydrate and energy metabolism. The present study gives new Insights into the pyrene stress response In maize leaves and demonstrates the power of the proteomlc approach in phytoremedlation of PAHs.

关键词： maize mass spectrometry proteomic pyrene stress.

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Interaction of Photoactive[Fe(CN)_6]^(4-) with TiO_2 Anatase(101) Surface:A Periodic Density Functional Theory Study

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Chinese Journal of Structural Chemistry 2007年第3期26卷 361-366页

作者： xu ying chen Wen-Kai CAO Mei-Juan LIU Shu-Hong LI Jun-Qian Department of Chemistry Fuzhou University Fuzhou Fujian 350002 China

The plane-wave pseudopotential function method, based on density-functional theory, has been used to calculate the adsorption, electronic band structures, orbitals and optical absorption spectrum of [Fe（CN）6]^4- on TiOz anatase（101） surface. Our calculations reveal that the surface-modified anatase system has large adsorption energy and a much narrower band gap. [Fe（CN）6]^4- adsorption on the （101） surface could lead to a large red shift of the anatase optical absorption threshold, which extends into a visible region significantly. The calculated results are in agreement with the experiment and other theoretical studies reasonably. It is very important for the understanding and further development ofphotovoltaic materials that are active under visible light.

关键词： density functional theory (DFT) [Fe(CN)6]^4- anatase(101) surface adsorption absorption

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Synthesis and Cytotoxic Activity of Novel Water-soluble Prodrugs of Combretastatin A-4

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Chinese Chemical Letters 2006年第1期17卷 23-26页

作者： Zhi Quart YONG Xiao Ping xu ying Chun chen xu BAO Ling Ling WENG Hu ZHENG Department of Medicinal Chemistry West China School of Pharmacy Sichuan University Chengdu 610041

Novel water-soluble prodrugs of combretastatin A-4 （5-8） were synthesized and evaluated for their in vitro cytotoxicity against lung carcinoma A549. Compound 5, bearing phosphoryl choline （PC） moiety, showed 90% inhibition at 32 ktg/mL concentration after 24 h. The findings showed the PC derivative would be a promising candidate for the development of new water-soluble prodrug of cytotoxic combretastatin A-4,

关键词： Combretastafin A-4 cytotoxicity phosphoryl choline water-soluble prodrug.

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Knockdown of Decoy Receptor 3 Impairs Growth and Invasiveness of Hepatocellular Carcinoma Cell Line of HepG2

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Chinese Medical Journal 2016年第21期129卷 2623-2629页

作者： Xiao-Na Zhou Guang-Ming Li ying-chen xu Tuan-Jie Zhao Ji-Xiang Wu Department of General Surgery Beijing Tongren Hospital Capital Medical University Beijing 100730 China Department of General Surgery Beijing Er Long Lu Hospital Beijing 100032 China

Background：Decoy receptor 3 （DcR3） binds to Fas ligand （FasL） and inhibits FasL-induced *** receptor is overexpressed in hepatocellular carcinoma （HCC）,and it is associated with the growth and metastatic spread of ***3 holds promises as a new target for the treatment of HCC,but little is known regarding the molecular mechanisms underlying the oncogenic properties of *** present work,therefore,examined the role of DcR3 in regulating the growth and invasive property of liver cancer cell ***：HepG2 cells were stably transfected with lentivirus-based short hairpin RNA vector targeting *** the knockdown of DcR3 was confirmed,cell proliferation,clone formation,ability of migrating across transwell membrane,and wound healing were assessed in *** metalloproteinase-9 （MMP 9） and vascular epithelial growth factor （VEGF）-C and D expressions of the DcR3 knockdown were also *** between multiple groups were done using one-way analysis of variance （ANOVA）,while pairwise comparisons were performed using Student＇s t test.P 〈 0.05 was regarded statistically ***：DcR3 was overexpressed in HepG2 compared to other HCC cell lines and normal hepatocyte *** knockdown of DcR3 slowed down the growth of HepG2 （P 〈 0.05） and reduced the number of clones formed by 50% compared to those without DcR3 knockdown （P 〈 0.05）.The knockdown also reduced the migration of HepG2 across transwell matrix membrane by five folds compared to the control （P 〈 0.05） and suppressed the closure of scratch wound （P 〈 0.05）.In addition,the messenger RNA levels of MMP 9,VEGF-C,and VEGF-D were significantly suppressed by DcR3 knockdown by 90% when compared with the mock control （P 〈 0.05）.Conclusions：Loss of DcR3 impaired the growth and invasive property of HCC cell line of *** DcR3 may be a potential therapeutic approach for the treatment of HCC.

关键词： Decoy Receptor 3 Hepatocellular Carcinonia Matrix Metalloproteinase 9 Neoplasm Metastasis Vascular Endothelial Growth Factor C Vascular Endothelial Growth Factor D

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N-doping offering higher photodegradation performance of dissolved black carbon for organic pollutants: experimental and theoretical studies

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第4期25卷 340-356页

作者： Yong GUO Mengxia chen Ting chen ying GUO Zixuan xu Guowei xu Soukthakhane SINSONESACK Keophoungeun KANMANY Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of EducationCollege of EnvironmentHohai UniversityNanjing 210093China Key Laboratory of Environmental Engineering of Jiangsu Province Jiangsu Provincial Academy of Environmental ScienceNanjing 210036China State Key Laboratory of Pollution Control and Resource Reuse Nanjing UniversityNanjing 210023China Central Environmental Laboratory Natural Resources and Environment Research InstituteMinistry of Natural Resources and EnvironmentVientiane 999012Laos

We investigated the influence mechanism of N-doping for dissolved black carbon(DBC)photodegradation of organic *** degradation performance of N-doped dissolved black carbon(NDBC)for tetracycline(TC)(71%)is better than that for methylene blue(MB)(28%)under *** levels are both better than DBC degradation performances for TC(68%)and MB(18%)under *** species quenching experiments suggest that h and-O,are the main reactive species for NDBC photodegraded TC,while-OH and h*are the main reactive species for NDBC photodegraded MB.-OH is not observed during DBC photodegradation of *** is likely because N-doping increases valence-band(VB)energy from 1.55 eV in DBC to 2.04 eV in NDBC;the latter is strong enough to oxidize water to ***,N-doping increases the DBC band gap of 2.29 to 2.62 eV in NDBC,resulting in a higher separation efficiency of photo-generated electrons-holes in NDBC than in *** these factors give NDBC stronger photodegradation performance for TC and MB than ***-performance liquid chromatography-mass spectrometry(HPLC-MS)characterization and toxicity evaluation with the quantitative structure-activity relationship(QSAR)method suggest that TC photodegradation intermediates produced by NDBC have less aromatic structure and are less toxic than those produced by *** adopted a theoretical approach to clarify the relationship between the surface groups of NDBC and the photoactive species *** results add to the understanding of the photochemical behavior of NDBC.

关键词： Dissolved black carbon(DBC) N-doping Organic pollutants Band gap Photodegradation

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