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The first photometric investigations of the G-type shallow contact binary IO Cnc
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作者 Wen-Ping Liao Lin-Jia Li +1 位作者 Xiao Zhou qi-shan wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第2期133-141,共9页
IO Cnc was classified to be a new G-type(G0)W UMa-type eclipsing binary system.Our first multicolor photometric solutions show that IO Cnc is a new W-subtype shallow contact binary with a fill-out factor of f=16.1%and... IO Cnc was classified to be a new G-type(G0)W UMa-type eclipsing binary system.Our first multicolor photometric solutions show that IO Cnc is a new W-subtype shallow contact binary with a fill-out factor of f=16.1%and a low mass ratio of q=3.12(or 1/q=0.32).During orbital period investigations,a cyclic variation and a downward parabolic variation with a rate of(-1.28±0.43)×10^(-7) d yr^(-1) was discovered in the observed–calculated(O-C)curve.The cyclic variation was analyzed by the light travel time effect(LTTE)via a potential red dwarf companion star,an orbital semi-major axis shorter than 4.88±0.82 AU was obtained.Finally,we collect physical parameters of a sample of 50 G-type shallow contact binaries(f≤20%),it is suggested that most of the G-type shallow contact binaries are undergoing a longterm and periodic orbital period changes,especially more systems show long-term decreases.The long-term orbital period decrease indicates that IO Cnc is in a mass transferring from the more massive component to the less massive one.With the long-term decrease of the orbital period,this shallow contact binary will evolve into a deeper contact one. 展开更多
关键词 STARS BINARIES close-stars BINARIES eclipsing-stars individual(IOCnc)-stars solar-type-stars evolution
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Photometric analysis of the eclipsing polar MN Hya
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作者 qi-shan wang Sheng-Bang Qian +3 位作者 Zhong-Tao Han Miloslav Zejda Eduardo Fernandez-Lajus Li-Ying Zhu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第7期11-20,共10页
As an eclipsing polar with a 3.39 h orbital period, MN Hya was going through a state change when we observed it during 2009-2016. Ten new mid-eclipse times, along with others obtained from literature, allow us to give... As an eclipsing polar with a 3.39 h orbital period, MN Hya was going through a state change when we observed it during 2009-2016. Ten new mid-eclipse times, along with others obtained from literature, allow us to give a new ephemeris. The residuals of a linear fit show that period decreased during the phase of state change, which means angular momentum was lost during this phase. The associated X-ray observation indicates the mass accretion rate was about 3.6 x 10^-9 Mo yr^-1. The period decrease indicates that at least 60% of mass being transferred from the secondary was lost, maybe in the form of spherically symmetric stellar wind. In the high state, the data show the intensity of flickering reduced when the system had a higher accretion rate, and that flickering sticks out with a primary timescale of about 2 min, which implies the position of the threading point was about 30 white dwarf radii above its surface. The trend of light curves for the system in its high state follows that of the low state for a large fraction of the phase interval from phase 0 to phase 0.4 since, starting at phase 0.4, the cyclotron feature is visible, and the primary intensity hump of the light curves near phase 0.7 when the system is in the high state did not appear on the curve when it was in the low state. Those facts contradict predictions of the two-pole model. 展开更多
关键词 TECHNIQUES photometric-stars cataclysmic variables eclipsing polars-stars individ-ual (MN Hya)
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Gastric Metastasis of Atypical Medullary Carcinoma from Breast:a Case Report
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作者 Bo Jin Yan-ping Liu +1 位作者 Hai-jiang wang qi-shan wang 《Chinese Medical Sciences Journal》 CAS CSCD 2012年第2期121-124,共4页
METASTATIC gastric tumors are clinically uncommon,and metastatic gastric cancer from breast cancer was rarely reported.Here we report a case of gastric metastasis of atypical medullary carcinoma from breast.
关键词 gastric metastasis breast cancer atypical medullary carcinoma
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Revisiting the X-ray emission of the asynchronous polar V1432 Aql
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作者 qi-shan wang Sheng-Bang Qian Li-Ying Zhu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第12期499-508,共10页
As the only eclipsing asynchronous polar,V1432 Aql provides an excellent laboratory to study the interaction between the accreted matter and the magnetic field.Here,we report an analysis of the X-ray data from the con... As the only eclipsing asynchronous polar,V1432 Aql provides an excellent laboratory to study the interaction between the accreted matter and the magnetic field.Here,we report an analysis of the X-ray data from the contemporaneous NuSTAR and Swift-XRT observations.The X-ray data present a profile with a low-intensity state for almost half an orbital period,a dip at 0.6 phase,and a peak at 0.75 phase,which suggests that there was only one accretion region during the observation and the claim is supported by the spectral analysis.The comparison with the previous data indicates that the X-ray data have an orbital modulation,as the case in BeppoSAX,rather than a spin one observed in ROSAT.We attribute the orbit and spin modulations to the different accretion geometries at work.The spectral analysis of the wide-band data presents a significant reflection effect,a commonly observed soft X-ray temperature,and the energy balance in V1432 Aql.Additionally,we obtained a low total accretion rate of 1.3×10~(-10)M yr~(-1)and a high specific accretion rate of 3.8 g cm~(-2)s~(-1)which explains the strong reflection from the surface of the white dwarf.However,due to its complex emission,a more physical understanding of its accretion geometry is still outstanding. 展开更多
关键词 stars:individual(V1432 Aql) cataclysmic variables:asynchronous polars
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