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A star-based method for precise wavelength calibration of the Chinese Space Station Telescope(CSST) slitless spectroscopic survey

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Research in Astronomy and Astrophysics 2021年第3期21卷 235-242页

作者： hai-Bo yuan Ding-Shan Deng yang Sun Department of Astronomy Beijing Normal UniversityBeijing 100875China

The Chinese Space Station Telescope(CSST)spectroscopic survey aims to deliver high-quality low-resolution(R>200)slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag,distributed within a large survey area(17500 deg2)and covering a wide wavelength range(255-1000 nm by three bands GU,GV,and GI).As slitless spectroscopy precludes the usage of wavelength calibration lamps,wavelength calibration is one of the most challenging issues in the reduction of slitless spectra,yet it plays a key role in measuring precise radial velocities of stars and redshifts of galaxies.In this work,we propose a star-based method that can monitor and correct for possible errors in the CSST wavelength calibration using normal scientific observations,taking advantage of the facts that(ⅰ)there are about ten million stars with reliable radial velocities now available thanks to spectroscopic surveys like LAMOST,(ⅱ)the large field of view of CSST enables efficient observations of such stars in a short period of time,and(ⅲ)radial velocities of such stars can be reliably measured using only a narrow segment of CSST spectra.We demonstrate that it is possible to achieve a wavelength calibration precision of a few km s^(-1) for the GU band,and about 10 to 20 kms^(-1) for the GV and GI bands,with only a few hundred velocity standard stars.Implementations of the method to other surveys are also discussed.

关键词： methods:data analysis methods:statistical techniques:spectroscopic techniques:radial velocities stars:fundamental parameters stars:kinematics and dynamics

Precision of the Chinese Space Station Telescope(CSST)stellar radial velocities

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Research in Astronomy and Astrophysics 2021年第4期21卷 207-215页

作者： yang Sun Ding-Shan Deng hai-Bo yuan Department of Astronomy Beijing Normal UniversityBeijing 100875China

The Chinese Space Station Telescope(CSST)spectroscopic survey plans to deliver high-quality low-resolution(R>200)slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag,covering a large survey area(17500 deg^(2))and a wide wavelength range(255-1000 nm by three bands GU,GV,and GI).In this work,we use empirical spectra of the Next Generation Spectral Library to simulate the CSST stellar spectra at R=250,and investigate their capabilities in measuring radial velocities.We find that velocity uncertainties depend strongly on effective temperature,weakly on metallicity for only FGK stars,and hardly on surface gravity.It is possible to deliver stellar radial velocities to a precision of about 3 kms^(-1)for AFGKM stars,and about 10 km s^(-1)for OB stars,at signal-to-noise ratio(SNR)of 100.Velocity uncertainties using single GU/GV/GI band spectra are also explored.Given the same SNR,the GU band performs best,the GV band the second best,and then the GI band.The effects of spectral normalization and the imperfect template on velocity measurements are investigated and found to be very weak.The uncertainties caused by wavelength calibration are considered and found to be moderate.Given the possible precision of radial velocities,the CSST spectroscopic survey can enable interesting science such as searching for hyper-velocity stars.Limitations of our results are also discussed.

关键词： methods:data analysis methods:statistical stars:fundamental parameters stars:kinematics and dynamics

New photometric studies for two deep,low-mass ratio overcontact binaries:Y Sex and V1363Ori

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Research in Astronomy and Astrophysics 2021年第11期21卷 189-201页

作者： yuan-Gui yang Shuang Wang Hui-Yu yuan hai-Geng Dai School of Physics and Electronic Information Huaibei Normal UniversityHuaibei 235000China

We present new photometry for two contact binaries,Y Sex and V1363 Ori,which were observed by three small telescopes in China.By using the W-D method,the absolute parameters are updated from new BVR light curves and previous radial velocity curves.Results identify that two binaries are deep,lowmass ratio(DLMR)overcontact binaries with q≤0.25 and f≥50%.From the temperature-luminosity diagram,the primary components are slightly evolved main-sequence stars,whose evolutionary ages are~2.51 Gyr for Y Sex and~3.56 Gyr for V 1363 Ori,respectively.From the(O-C)curves,it is found that the orbital periods may be undergoing secular increase with cyclic variations,which may be interpreted either by magnetic activity cycles or by the light-time orbit effect.With period increasing,this kind of DLMR overcontact binaries,such as Y Sex and V1363 Ori,will evolve into the rapid-rotating single stars.

关键词： binaries(including multiple):close binaries:eclipsing stars:fundamental parameters stars:individual(Y Sex,V1363 Ori)

Weathering geochemistry and palaeoclimate implication of the Early Permian mudstones from eastern Henan Province, North China

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Journal of Palaeogeography 2017年第4期6卷 370-380页

作者： Jiang-hai yang yuan-Sheng Du State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences

Terrigenous clastic sediments are generated by the integration of the Earth surface processes and their deep-time counterparts provide a valuable archive for regional/global climatic, geographic and landscape evolution. It is thus important to read and interpret these deep-time sedimentary records, especially for reconstructing continent climate. Previous studies on the Early Permian sequences from the North China document a dominant control of source chemical weathering on mudstone compositions and its linkage with continent climate conditions. Based on the weathering geochemical data of these mudstones, element mobility during weathering can be ordered as Ca 〉 Na ≥ Mg 〉 Sr 〉 K ≥ Ba 〉 Rb. The weathering regime in the source area is inferred to be supply-limited according to the estimated continent physical erosion rate and regional tectonic evolution, sedimentation in North China. Further exploration of palaeoclimate implication is presented in terms of variation of high-to-low latitudinal temperature gradient across the Early Permian glacial to post-glacial climate transition.

关键词： Chemical weathering Weathering geochemistry Mudstones Early Permian North China

Protective effects of Wuwei Xiaodu Drink against chronic osteomyelitis through Foxp3^(+)CD25^(+)CD4^(+) Treg cells via the IL-2/STAT5 signaling pathway

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Chinese Journal of Natural Medicines 2022年第3期20卷 185-193页

作者： HUANG Kai REN hai-Yong LIN Bing-yuan LIU Yi-yang GUO Qiao-Feng Department of Orthopedics Tongde Hospital of Zhejiang ProvinceHangzhou 310012China

To explore the effectiveness and safety of a Chinese medicinal decoction Wuwei Xiaodu Drink(WWXDD)in inhibiting chronic osteomyelitis via regulatory T cells signaling.The effective constitutes of WWXDD and osteomyelitis related genes were screened.Target proteins were cross-validated using the Venny database.GO function and KEGG pathway analysis were performed for target proteins,while pharmacological network was constructed.The bone properties were analyzed by HE staining and the concentrations of immune factors were measured by ELISA.The expression of CTLA-4 and Foxp3 mRNA and STAT5,p-STAT5,CTLA-4 and Foxp3 protein were detected using Real-time PCR and Western blot,respectively.FACS was used to analyze the percentages of cells.A total of 117 genes overlapped between 785 target genes of the active compounds of WWXDD and 912 osteomyelitis related genes.Inflammation-related genes,including IL-6,TNFα,IL-1βand IL-2 showed high connection degree in the drug-compound-disease-target network.GO function and KEGG pathway analysis revealed that 117 intersection genes mainly enriched in virus infection related pathways,immune related pathways and chemokine signaling pathway.Furthermore,the development of chronic osteomyelitis was suppressed in model rats after treatment with WWXDD.Meanwhile,the concentrations of IL-2 and CD4^(+)CD25^(+)Foxp3 Treg perr centages together with the levels of p-STAT5,CTLA-4 and Foxp3 were also down-regulated.Furthermore,IL-2 and WWXDD drug-containing serum exhibited opposite effects on regulating IL-2,IL-10,TGF-β1,Foxp3,CTLA4 and STAT5.In addition,a STAT5 phosphorylation inhibitor suppressed the expression of Foxp3 and CTLA-4.WWXDD can treat chronic osteomyelitis through suppressing the main regulating factors of Tregs and interfere its immunodepression.Our results bring a new solution for chronic osteomyelitis.

关键词： Chronic osteomyelitis Tregs Immunodepression Wuwei Xiaodu Drink

PS Vir:a short-period solar-like contact binary

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Research in Astronomy and Astrophysics 2018年第7期18卷 45-52页

作者： Hui-Yu yuan hai-Feng Dai yuan-Gui yang Information College Huaibei Normal University School of Physics and Electronic Information Huaibei Normal University

We present multi-color photometric observations and a one-dimensional spectrum, acquired from March 2016 to May 2017, for the short-period eclipsing binary PS Vir, by using the 2.16-m, 85-cm and 60-cm telescopes at Xinglong station, which is administered by National Astronomical Observatories, Chinese Academy of Sciences. The spectral type was determined as G2V from the one-dimensional spectrum. The photometric solution was reduced from BVRc light curves. The results imply that PS Vir is a W-subtype contact binary with a mass ratio of q - 0.305（zk0.008） and a fill-out factor of f = 14.4（＋1.8）%. The orbital period may be undergoing a cyclic oscillation with an ampli-tude of A = 0.0027（~0.0001）d and a modulated period of 11.7（4-0.2） yr, which may result from the light-time effect due to a third body. The lower limit on mass for the assumed component is 0.12 Me. Moreover, the more massive component of PS Vir may be a bit more evolved star as determined from the mass-luminosity diagram.

关键词： binaries close-binaries eclipsing-stars individual（PS Vir）-stars

Spliceosomal GTPase Eftud2 regulates microglial activation and polarization

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Neural Regeneration Research 2023年第4期18卷 856-862页

作者： Guo-Chao yang yuan Shi Chao-Nan Fan Ying Li Meng-Qi yuan Jie Pei Yan Wu hai-Tao Wu School of Basic Medicine Qingdao UniversityQingdaoShandong ProvinceChina Department of Neurobiology Beijing Institute of Basic Medical SciencesBeijingChina Institute of Neuroscience Hengyang Medical CollegeUniversity of South ChinaHengyangHunan ProvinceChina School of Basic Medicine Anhui Medical UniversityHefeiAnhui ProvinceChina Key Laboratory of Neuroregeneration Co-innovation Center of NeuroregenerationNantong UniversityNantongJiangsu ProvinceChina

Elongation factor Tu GTP binding domain protein 2(Eftud2)is a spliceosomal GTPase that serves as an innate immune modulator restricting virus infection.Microglia are the resident innate immune cells and the key players of immune response in the central nervous system.However,the role of Eftud2 in microglia has not been reported.In this study,we performed immunofluorescent staining and western blot assay and found that Eftud2 was upregulated in microglia of a 5xFAD transgenic mouse model of Alzheimer’s disease.Next,we generated an inducible microglia-specific Eftud2 conditional knockout mouse line(CX3CR1-CreER;Eftud2^(f/f) cKO)via Cre/loxP recombination and found that Eftud2 deficiency resulted in abnormal proliferation and promoted anti-inflammatory phenotype activation of microglia.Furthermore,we knocked down Eftud2 in BV2 microglia with siRNA specifically targeting Eftud2 and found that Eftud2-mediated regulation of microglial proinflammatory/anti-inflammatory phenotype activation in response to inflammation might be dependent on the NF-κB signaling pathway.Our findings suggest that Eftud2 plays a key role in regulating microglial polarization and homeostasis possibly through the NF-κB signaling pathway.

关键词： Alzheimer’s disease anti-inflammatory phenotype BV2 Eftud2 inflammation lipopolysaccharide microglia nuclear factor-kappaB proinflammatory phenotype spliceosomal GTPase

Peripheral Delivery of Ganglioside GM1 Exacerbates the Pathogenesis of Alzheimer’s Disease in a Mouse Model

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Neuroscience Bulletin 2022年第1期38卷 95-98页

作者： Chuang-Chuang yang yuan Cheng hai-Mei yang yang Chen Yan-Jiang Wang Zhi-Qiang Xu Ye-Ran Wang Department of Neurology and Clinical Center for Neuroscience Daping HospitalThird Military Medical UniversityChongqing400042China

Dear Editor,Alzheimer’s disease(AD)is the most common cause of dementia among the older population,and is characterized by amyloid-beta(Aβ)accumulation,hyperphosphorylation of tau,and finally neurodegeneration in the brain[1].Aβ is the major pathological agent in AD,thus currently most efforts in developing therapies for AD target this peptide.The most promising therapy for this disease is immunotherapy.

关键词： GM1 Alzheimer Aβ tau

A photometric-spectroscopic study of the infrared-excess eclipsing binary V2364 Cyg

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Research in Astronomy and Astrophysics 2020年第12期20卷 307-316页

作者： Hui-Yu yuan Lin-Qiao Jiang hai-Feng Dai Shuang Wang yuan-Gui yang Information College&School of Physics and Electronic Information Huaibei Normal UniversityHuaibei 235000China Artificial Intelligence Key Laboratory of Sichuan Province Sichuan University of Science&EngineeringZigong 643000China

The eclipsing binary V2364 Cyg is an A7 V-type contact binary with a period of 0.5921 d.We present six spectra from LAMOST and BVRc light curves(LCs),which are simultaneously analyzed to obtain the absolute physical parameters.The first light maxima are brighter than the second ones by up to 0.m038,0.m036 and 0.m024 for BVRc bands,respectively.These distorted LCs are modeled by a cool spot on the less massive component.Its mass ratio and over-contact degree are q=0.319(±0.004) and f=28.4%(±1.0) % respectively.From the mass-luminosity diagram,the primary component is a normal main-sequence star,while the secondary one is a subgiant star.From the(O-C) curve,the orbital period secularly decreases at a rate dP/dt=-1.62(±0.03) × 10^-7 dyr^-1,which is mainly attributed to mass loss via stellar wind from the binary system.This may result in the observed infrared excess in the W4 band.

关键词： stars:circumstellar matter stars:binaries:close stars:individual(V2364 Cyg) mass loss infrared excess