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CSS J075415.6+191052 and NW Leo: Two Contact Binaries at Different Evolutionary Stages

Research in Astronomy and Astrophysics 2022年第2期22卷 118-127页

作者： Xu-Dong Zhang sheng-bang qian Er-Gang Zhao Qi-Jun Zhi Ai-Jun Dong Bin Zhang School of Physics and Electronic Science Guizhou Normal University550025 GuiyangChina Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550025 GuiyangChina Yunnan Observatories Chinese Academy of Sciences(CAS)650216 KunmingChina University of Chinese Academy of Sciences(UCAS) 100049 BeijingChina

Multi-color light curves of CSS J075415.6+191052 and NW Leo are presented and the photometric solutions suggest that CSS J075415.6+191052 is an A-subtype contact binary with low mass ratio(q = 0.178) while NW Leo has a high mass ratio(q = 0.707). For CSS J075415.6+191052, the RI light curves show weakening around the left shoulder of the secondary minimum, which indicates that there may be a dark spot on the secondary component. However, the light curves of BV bands are totally symmetric. It is unreasonable if the dark spot is caused by magnetic activity or mass transfer between the two components. Therefore, weakening of the light curves in this contact binary is caused by something else. A possible explanation is mass transferring from the primary component to the common convective envelope through the inner Lagrangian point, and this part of the mass, for some reason, weakens the RI bands of light from the secondary component. O-C analysis of NW Leo reveals a cyclic period change with a modulation period of 4.7 yr, which may be caused by the light travel time effect of a third body. The positions of CSS J075415.6+191052 and NW Leo in the P–J′_(orb)diagram indicate that CSS J075415.6+191052 mainly abides by the angular momentum loss theory while NW Leo is dominated by the thermal relaxation oscillation theory.

关键词： (stars:)binaries:eclipsing stars:evolution stars:individual(CSS J075415.6+191052 NW Leo)

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Electroacupuncture Promotes Angiogenesis in Mice with Cerebral Ischemia by Inhibiting miR-7

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Chinese Journal of Integrative Medicine 2024年第6期30卷 543-550页

作者： YU qian SHU Shi JU Xin-yao PENG Wei REN Xue-qi SI Shu-han SONG Shi-zhen XIE Xue-yun FANG bang-jiang ZHOU Shuang School of Acupuncture-Moxibustion and Tuina Shanghai University of Traditional Chinese MedicineShanghai201203China College of Basic Medicine Shanghai University of Traditional Chinese MedicineShanghai201203China Department of Emergency Longhua HospitalShanghai University of Traditional Chinese MedicineShanghai200032China

Objective To observe the angiogenesis effect of electroacupuncture(EA)at Shuigou acupoint(GV 26)in the treatment of cerebral ischemia,and explore the value of miRNA-7(miR-7)in it.Methods First,48 mice were randomly divided into sham operation,middle cerebral artery occlusion(MCAO)model,and EA treatment groups.Then 9 mice were divided into carrier control group,miR-7 knockout group and miR-7 overexpression group(n=3 each group).Finally,20 mice were divided into model and carrier control group,model and miR-7 knockout group,EA treatment and carrier control group and EA treatment and miR-7 overexpression group,with 3–6 mice in each group.The MCAO model was established in the MCAO and EA groups.Neurological deficit score and 2,3,5-triphenyltetrazolium chloride(TTC)staining were used to evaluate the severity of cerebral ischemia.Hematoxylin-eosin staining was used to describe basic pathological changes.Immunohistochemistry was used to quantify cerebral microvessel density.Real-time PCR and Western blot were used to detect the expression of miR-7 and its downstream target genes Krüppel-like factor 4/vascular endothelial growth factor(KLF4/VEGF)and angiopoietin-2(ANG-2)in the ischemic cerebral cortex.Results After EA,neurological deficit scores and infarction volumes decreased,and the density of cerebral microvessels increased.In the MCAO group,miR-7 expression was higher than that in the sham group(P<0.01).After EA at GV 26,miR-7 expression decreased(P<0.01)and the expression of downstream target genes KLF4/VEGF and ANG-2 increased as compared with the MCAO group(P<0.01).After EA combined with overexpression of miR-7,the expression of downstream target genes KLF4/VEGF and ANG-2 decreased compared to the control EA group(P<0.01).After miR-7 knockdown,the expression of KLF4/VEGF and ANG-2 increased(P<0.05 or P<0.01).Conclusions EA could promote angiogenesis in MCAO mice likely by inhibiting the expression of miR-7 and relieving inhibition of downstream target genes KLF4/VEGF and ANG-2.

关键词： electroacupuncture cerebral ischemia miRNA-7 angiogenesis Shuigou(GV 26) acupuncture points

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Orbital period correction and light curve modeling of the W-subtype shallow contact binary OW Leo

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Research in Astronomy and Astrophysics 2021年第2期21卷 24-30页

作者： Xiao Zhou sheng-bang qian Yunnan Observatories Chinese Academy of Sciences(CAS)Kunming 650216China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China University of the Chinese Academy of Sciences Beijing 100049China

Orbital period and multi-color light curves’investigation of OW Leo are presented for the first time.The orbital period of OW Leo is corrected from P=0.325545 days to P=0.32554052 days in our work,and the observational data from the All-Sky Automated Survey for Super Novae(ASAS-SN)are used to test the newly determined orbital period.Then,the phased light curves are calculated with the new period and the Wilson-Devinney program is applied to model the light curves,which reveal that OW Leo is a W-subtype shallow contact binary system(q=3.05,f=12.8%).The absolute physical parameters of the two component stars are estimated to be M_(1)=0.31(1)M_(⊙),M_(2)=0.95(3)M_(⊙),R_(1)=0.63(1)R⊙,R_(2)=1.04(1)R_(⊙),L_(1)=0.43(1)L_(⊙)and L_(2)=1.01(2)L_(⊙).The evolutionary status shows that the more massive star is less evolved than the less massive star.OW Leo has very low metal abundance,which means its formation and evolution are hardly influenced by any additional component.It is formed from an initially detached binary system through nuclear evolution and angular momentum loss via magnetic braking,and has passed a very long time of main sequence evolution.

关键词： techniques photometric-binaries eclipsing-stars evolution

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Two particular EA-type binaries in the globular cluster ω Centauri

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Research in Astronomy and Astrophysics 2013年第7期13卷 827-834页

作者： Kai Li sheng-bang qian National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences

We analyzed the B and V light curves of two EA-type binaries V211 and NV358 for the first time using the Wilson-Devinney code. Our analysis shows that V211 is a typical Algol-type binary and NV358 is a well detached binary system. As the two binaries are definite members of ω Centauri due to their proper motion, we estimated their physical parameters, obtaining M1 = 1.13 4±0.03 M⊙, R1 = 0.98±0.01 R⊙, M2 = 0.33 ±0.01 M⊙ and R2 = 0.92 ±0.01 R⊙ forV211; M1 = 1.304-0.05 M⊙, R1 = 1.03±0.01 R⊙, M2 = 0.58±0.02 M⊙ and R2 = 0.78±0.01 R⊙ for NV358. On the color-magnitude diagram of ω Centauri, V211 is located in the faint blue straggler region and its primary component is more massive than a star at the main-sequence turnoff. Therefore, V211 is a blue straggler and was formed by mass transfer from the secondary component to the primary. The age of NV358 is less than 1.93 Gyr, indicating that it is much younger than the first generation of stars in ω Centaufi. Like NV364 in ω Centaufi, NV358 should be a second-generation binary.

关键词： galaxies： globular clusters： individual （ω Centauri） - stars： binaries：close - stars： binaries： eclipsing - stars： blue stragglers - stars： individual （V211,NV358）

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Mechanical property and thermal shock behavior of tungsten-yttria-stabilized zirconia cermet fabricated by spark plasma sintering

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Tungsten 2024年第1期6卷 134-140页

作者： Lin-Chao Zhang Ke Jing Rui Liu Zhuo-Ming Xie Jun-Feng Yang Gang Li Xian-Ping Wang Xue-bang Wu qian-Feng Fang Chang-Song Liu Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610041China

The cermet fuels have been considered as a potential key component for the nuclear thermal propulsion,and the homogeneity of the fuel particles in the metal matrix plays a crucial role in stabilizing the structure at extremely high temperatures.In this work,liquid paraffin was used as additive to improve the distribution of yttria-stabilized zirconia(YSZ,an appropriate surrogate for UO_(2) fuel)microspheres in the tungsten(W)matrix,and the W-YSZ cermet wafers(volume ratio 1:1)with a relative density of 97.6%were fabricated by spark plasma sintering with a specifically designed program.The effects of the paraffin dosage(0-5 wt.%)on the homogeneity,microstructure,mechanical properties,and the thermal conductivity of W-YSZ cermet were investigated.The W-YSZ sample with 2 wt.%paraffin shows the highest homogeneity and exhibits the best comprehensive properties,including the ultimate tensile strength of 132.2 MPa at 600℃,the bending strength of455 MPa and thermal conductivity of 50 W·m^(-1)·K^(-1)at room temperature.Moreover,the cermet could keep structurally sound after thermal shocked at a heat load of 20 MW·m^(-2).These results would be helpful for the design and optimization of the cermet fuels in the nuclear thermal propulsion.

关键词： Nuclear thermal propulsion Tungsten Cermet Liquid paraffin Thermal shock

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A Photometric Study of the W UMa-Type Contact Binary RZ Com

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Chinese Journal of Astronomy and Astrophysics 2008年第4期8卷 465-471页

作者： Jia-Jia He sheng-bang qian National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China United Laboratory of Optical Astronomy Chinese Academy of Sciences （ULOAC） Beijing 100012 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

We present results of CCD photometric observations of the short-period W UMatype contact binary system, RZ Com. The light curve of the binary has changed from Wsubtype to A-subtype from 1998 to 2003, then back to W-subtype in 2004. An analysis was carried out using the 2003 version of the Wilson-Devinney code. It is confirmed that RZ Com is a low-degree, overcontact f = 20.1% （±7.4%） binary system with a high inclination of i = 81.°40 （＋0.°40）, and a mass ratio q = 2.351 （＋0.031）. Combining four newly determined times of light minimum with others in the literature, the variations in orbital period is examined. A small-amplitude oscillation （A=0.0065d）, with a period of 41.5 year, is discovered superimposed on a long-term increase at rate dP/dt = ＋3.97 × 10^-8d yr^-1. The period oscillation can be explained either by the light-time effect due to the presence of an unseen third body, or by cycles of magnetic activity on the components. Combining our photometric solution with the spectroscopic elements obtained by Mclean ＆ Hilditch, the absolute dimensions ofRZ Com are： M1 = 1.14 （±0.19）M⊙, M2 = 0.50 （±0.09）M⊙, R1 = 1.12 （±0.01）R⊙, R2 = 0.78 （＋0.01）R⊙ and A = 2.41 （±0.02）R⊙.

关键词： stars binaries close - stars binaries eclipsing - stars individual RZ Com

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Investigations into the thermal non-equilibrium of W UMa-type contact binaries

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Research in Astronomy and Astrophysics 2018年第5期18卷 83-92页

作者： Xiao Xiong Liang Liu sheng-bang qian Yunnan Observatories Chinese Academy of Sciences Kunming 650011 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Traditionally, some physical details（e.g., magnetic braking, energy transfer, angular momentum loss, etc.） have to be taken into consideration during investigations into the evolution of contact binaries. However, the real evolutionary processes which usually contain several of these physical mechanisms are very complicated as a result of strong interaction between components. To avoid dealing with these factors, a linear relationship is applied to the temperatures of components. It is found that the higher the mass ratio（M2/M1） of a contact system, the weaker the deviation from thermal equilibrium.On this basis, a variation trend of fill-out factor（f） changing with mass ratio can be inferred, which is consistent with observations. Moreover, if we stick to this point of view, it should be natural that the number of semi-detached binaries in the predicted broken-contact phase of relaxation oscillations is less than the number in the contact phase.

关键词： stars binaries close - stars binaries eclipsing - stars evolution

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SDSS J012119.10 001949.9:a very short period M dwarf contact binary from SDSS stripe 82

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Research in Astronomy and Astrophysics 2015年第12期15卷 2237-2243页

作者： Lin-Qiao Jiang sheng-bang qian Jia Zhang Yunnan Observatories Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences

We present the first multicolor photometric observations of the short period low-mass eclipsing binary SDSS J012119.10-4301949.9. By using the 2013 version of the Wilson-Devinney code, the photometric solutions are derived. It is found that the system is in a contact configuration （f = 18.9± 6.0%） with a moderate mass ratio of 0.5 ± 0.01. A third light contributing about 6.1± 1.3% of the total luminosity in the V band was found, which may come from a cool tertiary component. The derived high orbital inclination （i - 83.9°± 0.5°） and the almost symmetric three light curves suggest that the determined parameters are reliable. Both the color class and spectral class of the system correspond to a spectral type of M0, which may indicate that SDSS J012119.10-001949.9 belongs to a very rare class of M dwarf contact binaries that are below the theoretical short period limit.

关键词： binaries： eclipsing -- stars： individual （SDSS J012119.10-001949.9） --techniques： photometric

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On properties of mass transfer in an Algol-type binary system:an example of VV Vir

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Research in Astronomy and Astrophysics 2014年第2期14卷 179-192页

作者： Jia Zhang sheng-bang qian Lin-Qiao Jiang Yunnan Observatories Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences

Some properties of mass transfer within a semi-detached binary system are discussed based on an example of VV Vir. The observations and analysis of VV Vir show that it is a semi-detached binary system with the less massive cooler component filling its Roche lobe, which is also called an Algol-type binary system. Based on the parameters of this semi-detached binary, a theoretical study on the mass flow is carded out, including the trajectory of the mass flow, the position, radius and temperature of the impact spot caused by the mass flow, the inconsistent form of the mass flow and the possibly huge rate of energy transfer carried by the mass flow. Humps and distortions in light curves of VV Vir are deemed to be weak evidence for the theoretical results.

关键词： binaries eclipsing -- stars individual （VV Vir） -- techniques photo-metric

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Candidates of eclipsing multiples based on extraneous eclipses on binary light curves： KIC 7622486, KIC 7668648, KIC 7670485 and KIC 8938628

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Research in Astronomy and Astrophysics 2017年第3期17卷 1-12页

作者： Jia Zhang sheng-bang qian Jian-Duo He Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China

Four candidates of eclipsing multiples, based on new extraneous eclipses found on Kepler binary light curves, are presented and studied. KIC 7622486 is a double eclipsing binary candidate with orbital periods of 2.2799960 d and 40.246503 d. The two binary systems do not eclipse each other in the line of sight, but there is mutual gravitational influence between them which leads to the small but definite eccentricity of 0.0035（0.0022） associated with the short 2.2799960 d period orbit. KIC 7668648 is a hierarchical quadruple system candidate, with two sets of solid 203 4- 5 d period extraneous eclipses and another independent set of extraneous eclipses. A clear and credible extraneous eclipse is found on the binary light curve of KIC 7670485 which makes it a triple system candidate. Two sets of extraneous eclipses with periods of about 390 d and 220 d are found on KIC 8938628 binary curves, which not only confirm the previous conclusion of the 388.5 4- 0.3 triple system, but also indicate new additional objects that make KIC 8938628 a hierarchical quadruple system candidate. The results from these four candidates will contribute to the field of eclipsing multiples.

关键词： binaries eclipsing - techniques photometric - methods observational

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