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S1280 and S1284: Two Oscillating Blue Stragglers in the Open Cluster M67

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Chinese Journal of Astronomy and Astrophysics 2005年第6期5卷 579-586页

作者： xiao-bin zhang Rong-Xian zhang Zhi-Ping Li National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

We present results of a time-series CCD photometry of two blue stragglers in the open cluster M67 that are also oscillating variables, S1280 and S1284. The observations obtained on 11 nights confirmed the δ Scuti-like variability of the two stars. Four and five main pulsating frequencies are detected for S1280 and S1284, respectively, through a power spectral analysis. A preliminary mode identification indicates that the two stars are both in radial oscillation. Based on the nature of oscillation, the physical parameters of the two stars are determined, and their evolutionary status discussed.

关键词： blue straggler - open cluster individual (M67) - stars oscillation - stars individual (S1280, S1284)

The semi-detached binary system IU Per and its intrinsic oscillation

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Chinese Journal of Astronomy and Astrophysics 2009年第4期9卷 422-430页

作者： xiao-bin zhang Rong-Xian zhang Qi-Sheng Li National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

We present a long-term time-resolved photometry of the short-period eclipsing binary IU Per. It confirms the intrinsic 6 Scuti-like pulsation of the system reported by Kim et al.. With the obtained data, an orbital period study and an eclipsing light curve synthesis based on the Wilson-Devinney method were carded out. The photometric solution reveals a semi-detached configuration with the less-massive component filling its own Roche-lobe. By subtracting the eclipsing light changes from the data, we obtained the pure pulsating light curve of the mass-accreting primary component. A Fourier analysis reveals four pulsation modes with confidence larger than 99%. A mode identification based on the results of the photometric solution was made. It suggests that the star may be in radial pulsation with a fundamental period of about 0.0628 d. A brief discussion concerning the evolutionary status and the pulsation nature is finally given.

关键词： stars binaries eclipsing-stars oscillations-stars individual (IU Per)

Modeling blue stragglers in young clusters

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Research in Astronomy and Astrophysics 2011年第11期11卷 1336-1350页

作者： Pin Lu Li-Cai Deng xiao-bin zhang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academyof Sciences Beijing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

A grid of binary evolution models are calculated for the study of a blue straggler （BS） population in intermediate age （log Age = 7.85 - 8.95） star clusters. The BS formation via mass transfer and merging is studied systematically using our models. Both Case A and B close binary evolutionary tracks are calculated for a large range of parameters. The results show that BSs formed via Case B are generally bluer and even more luminous than those produced by Case A. Furthermore, the larger range in orbital separations of Case B models provides a probability of producing more BSs than in Case A. Based on the grid of models, several Monte-Carlo simulations of BS populations in the clusters in the age range are carded out. The results show that BSs formed via different channels populate different areas in the color magnitude diagram （CMD）. The locations of BSs in CMD for a number of clusters are compared to our simulations as well. In order to investigate the influence of mass transfer efficiency in the models and simulations, a set of models is also calculated by implementing a constant mass transfer efficiency,β=0.5, during Roche lobe overflow （Case A binary evolution excluded）. The result shows BSs can be formed via mass transfer at any given age in both cases. However, the distributions of the BS populations on CMD are different.

关键词： stars blue stragglers-stars binaries close

Solubility study of hydrogen in direct coal liquefaction solvent based on quantitative structure–property relationships model

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Chinese Journal of Chemical Engineering 2023年第12期64卷 250-258页

作者： xiao-bin zhang A.Rajendran Xing-Bao Wang Wen-Ying Li State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China Department of Chemistry Mepco Schlenk Engineering College(Autonomous)Sivakasi 626005Tamil NaduIndia

Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel *** DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature and pre-hydrogenation of the DCLS are critical ***,studying the dissolution of hydrogen in DCLS under liquefaction conditions gains ***,it is difficult to precisely determine hydrogen solubility only by experiments,especially under the actual DCL *** address this issue,we developed a prediction model of hydrogen solubility in a single solvent based on the machine-learning quantitative structure–property relationship(ML-QSPR)*** results showed that the squared correlation coefficient R^(2)=0.92 and root mean square error RMSE=0.095,indicating the model’s good statistical *** external validation of the model also reveals excellent accuracy and predictive *** polarization(a)is the main factor affecting the dissolution of hydrogen in *** hydrogen solubility in acyclic alkanes increases with increasing carbon *** in polycyclic aromatics,it decreases with increasing ring number,and in hydrogenated aromatics,it increases with hydrogenation *** work provides a new reference for the selection and proportioning of DCLS,i.e.,a solvent with higher hydrogen solubility can be added to provide active hydrogen for the reaction and thus reduce the hydrogen ***,it brings important insight into the theoretical significance and practical value of the DCL.

关键词： Hydrogen solubility Liquefied solvents Predictive model Density generalized function theory Quantitative structure-property relationship

Viewing the current situation of pig model application in China’s medical field from the application and funding of NSFC

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Journal of Otology 2021年第1期16卷 34-39页

作者： xiao bin zhang Shi-Ming Yang Department of Health Sciences National Natural Science Foundation of ChinaChina College of Otolaryngology Head and Neck Surgery Chinese PLA General HospitalChinese PLA Medical SchoolNo.28 Fuxing RoadBeijing100853China National Clinical Research Center for Otolaryngologic Diseases Beijing100853China State Key Lab of Hearing Science Ministry of EducationBeijing100853China Beijing Key Lab of Hearing Impairment Prevention and Treatment Beijing100853China

Background:The National Natural Science Foundation of China(NSFC)is an important part of China’s innovation *** the last decade,the pig has become more and more widely used in the field of medical science,especially in otology ***:By analyzing and summarizing the funding information over recent years,we intend to identify the characteristics and trends of funding for research using pig models and provide references for future *** and methods:This is a comprehensive analysis of features in funding for research projects involving pig models by the NSFC in the past 10 years,with a focus on projects in the field of otolaryngology/head and neck ***:Both the number and amount of funding provided by the NSFC for research involving pig models are on the rise with each passing *** at the PLA General Hospital have completed a number of studies using miniature pigs in cochlear morphology,electrophysiology,cochlear implantation,cochlear transcription analysis,gene therapy,inner ear disease modeling and Eustachian tube pathology ***:Pigs as an ideal large mammal model are well suited in the current national basic research strategy in China,and can help further strengthen China’s leading position in basic research in the world.

关键词： Animal model National natural science foundation Otolaryngology

Cavitation erosion behavior of WC coatings on CrNiMo stainless steel by laser alloying

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International Journal of Minerals,Metallurgy and Materials 2009年第2期16卷 203-207页

作者： xiao-bin zhang Chang-sheng Liu xiao-dong Liu Jiang Dong Bo Yu School of Materials and Metallurgy Northeastern University Shenyang 110004 China School of Material Science and Engineering Chongqing Institute of Technology Chongqing 400050 China Shenyang Research Institute of Foundry Shenyang 110022 China

The WC powder was precoated on the surface of CrNiMo stainless steel and then made into an alloying layer by using the laser alloying technique. Phases in the layers were investigated by X-ray diffraction （XRD） analysis and surface morphologies after cavitation erosion were observed with the help of scanning electron microscopy （SEM）. The cavitation erosion behavior of the CrNiMo stainless steel and WC laser alloying layer in distilled water was tested with the help of ultrasonic vibration cavitation erosion equipment. The results showed that the thickness of the laser alloying layer was about 0.13 mm. The layer had a dense microstructure, metallurgically bonded to the substrate, and no crack had been found. The cavitation erosion mass loss rate of the laser alloying layer was only 2/5 that of the CrNiMo stainless steel. The layer had better cavitation resistance properties because of its metallurgical combination and the strengthening effects of the precipitate phases.

关键词： martensite stainless steel laser surface alloying cavitation erosion WC

Photometric Monitoring of ROSAT-Selected Weak Line T Tauri Stars

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Chinese Journal of Astronomy and Astrophysics 2006年第6期6卷 716-722页

作者： Li-Feng Xing xiao-bin zhang Jian-Yan Wei National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Department of Technology and Physics Zhengzhou University of Light Industry Zhengzhou 450002

We monitored the light curves of 22 weak-line T Tauri stars （WTTSs） discovered among the X-ray sources in the field of the Taurus-Auriga cloud. For 12 of the 22 WTTSs photometric periodic variability is confirmed and their rational periods are determined using Phase Dispersion Minimization （PDM） and Fourier analysis. Most of them are found to have periods shorter than one day. This gives further evidence for the spin up of solar-type stars predicted by the models of angular momentum evolution of pre-main sequence stars.

关键词： stars late-type- stars pre-main sequence- stars rotation

V551 Aur,an oEA binary with g-mode pulsations?

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Research in Astronomy and Astrophysics 2012年第6期12卷 671-677页

作者： Nian Liu xiao-bin zhang An-bin Ren Li-Cai Deng Zhi-Quan Luo Institute of Theoretical Physics China West Normal University Nanchong 637002 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

We present time-series CCD photometry of V551 Aur, an eclipsing binary located in the open cluster NGC 2126 that shows δ Scuti-like pulsations. Complete covered light curves in theBand V bands were obtained with high-precision over nine nights. Based on them, a revised orbital period and the first photometric solutions were determined. Our eclipsing light-curve synthesis reveals a detached configura- tion for the binary system with a mass-ratio of about 0.73, and the mean density of the pulsating primary component was deduced to be about （0.532±0.005）ρ. A fre- quency analysis of the eclipse-subtracted light curve yields two reliable frequencies at f1=7.727013（c/d） and f2=15.45403（c/d）, respectively. With the help of the derived mean density, mode identification was performed. The result suggests that the primary component of V551 Aur is very probably g-mode oscillations.

关键词： stars: binaries: eclipsing -- stars: oscillations -- stars: individual (V551Aur) -- open cluster: individual (NGC 2126)

Computational fluid dynamic simulation of an inter-phasing pulse tube cooler

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 93-98页

作者： xiao-bin zhang Zhi-hua GAN Li-min QIU Hua-xiang LIU Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China College of Science Guangdong Ocean University Zhanjiang 524088 China

An inter-phasing pulse tube cooler (IPPTC) consists of two pulse tube units, which are connected to each other at hot ends of the pulse tubes through a needle valve. This paper presents the computational fluid dynamic (CFD) results of an IPPTC using a 2D axis-symmetrical model. General results such as the phase difference between pressure and velocity at cold end and hot end, the temperature profiles along the wall, the available lowest temperature as well as its oscillations and the coefficient of performance (COP) for IPPTC are presented. The formation of DC flow and its effects on the performance of the cooler are investigated and analyzed in detail. Turbulence, which is partially responsible for the poor overall performance of a single orifice pulse tube cooler (OPTC), is found to be much reduced in IPPTC and its performance is improved significantly compared with the single OPTC.

关键词： Inner-phasing Pulse tube cooler (PTC) Computational fluid dynamic (CFD)