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Mid-infrared Period-Luminosity Relations of Gaia DR3 Long Period Variables

Research in Astronomy and Astrophysics 2024年第7期24卷 56-70页

作者： Xiaohan chen Xiaodian chen Licai Deng Shu Wang tianlu chen Department of Physics College of ScienceTibet UniversityLhasa 850000China Key Laboratory of Cosmic Rays(Tibet University) Ministry of EducationLhasa 850000China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of the Chinese Academy of SciencesBeijing 100049China Department of Astronomy China West Normal UniversityNanchong 637009China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China

Long period variable(LPV)stars are very promising distance indicators in the infrared *** selected asymptotic giant branch(AGB)stars in the Large and Small Magellanic Cloud(LMC and SMC)from the Gaia Data Release 3 LPV catalog,and classified them into oxygen-rich(O-rich)and carbon-rich(C-rich)AGB *** the Wide-field Infrared Survey Explorer database,we determined the W1-and W2-band period-luminosity relations(PLRs)for each pulsation-mode sequence of AGB *** dispersion of the PLRs of O-rich AGB stars in sequences C'and C is relatively small,around 0.14 *** PLRs of LMC and SMC are consistent in each *** the W2 band,the PLR of large-amplitude C-rich AGB stars is steeper than that of small-amplitude C-rich AGB stars,due to their more circumstellar *** two methods,we find that some PLR sequences of O-rich AGB stars in the LMC are dependent on *** coefficients of the metallicity effect areβ=-0.533±0.213 mag dex~1andβ=-0.767±0.158 mag dex~1for sequence C in W1 and W2 bands,*** significance of the metallicity effect in W1 band for the four sequences is 2.2-3.5σ.Both of these imply that distance measurements using O-rich Mira may need to take the metallicity effect into account.

关键词： stars variables general-stars distances-infrared stars

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Microphysical Characteristics of Rainfall Based on Long-Term Observations with a 2DVD in Yangbajain,Tibet

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Advances in Atmospheric Sciences 2024年第9期41卷 1721-1734页

作者： Ming LI Yongheng BI Yonghai SHEN Yinan WANG Ciren Nima tianlu chen Daren LYU Key Laboratory for Cosmic Rays of the Ministry of Education Tibet UniversityLhasa 850000China Key Laboratory of Middle Atmosphere and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChinese Academy of ScienceBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Raindrop size distribution(DSD)plays a crucial role in enhancing the accuracy of radar quantitative precipitation estimates in the Tibetan Plateau(TP).However,there is a notable scarcity of long-term,high-resolution observations in this *** address this issue,long-term observations from a two-dimensional video disdrometer(2DVD)were leveraged to refine the radar and satellite-based algorithms for quantifying precipitation in the hinterland of the *** was observed that weak precipitation(R<1,mm h-1)accounts for 86%of the total precipitation time,while small raindrops(D<2 mm)comprise 99%of the total raindrop ***,the average spectral width of the DSD increases with increasing rain *** DSD characteristics of convective and stratiform precipitation were discussed across five different rain rates,revealing that convective precipitation in Yangbajain(YBJ)exhibits characteristics similar to maritime-like *** constrained relationships between the slopeΛand shapeμ,D_(m)and N_(w)of gamma DSDs were ***,we established a correlation between the equivalent diameter and drop axis ratio and found that raindrops on the TP attain a nearly spherical ***,the application of the rainfall retrieval algorithms of the dual-frequency precipitation radar in the TP is improved based on the statistical results of the DSD.

关键词： Tibetan Plateau raindrop size distribution 2DVD dual frequency radar microphysical features

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Consensus on rapid screening for prodromal Alzheimer's disease in China

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General Psychiatry 2024年第1期37卷 1-16页

作者： Lin Huang Qinjie Li Yao Lu Fengfeng Pan Liang Cui Ying Wang Ya Miao tianlu chen Yatian Li Jingnan Wu Xiaochun chen Jianping Jia Qihao Guo Department of Gerontology Shanghai Sixth People's Hospital Afiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina Center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina shanghai BestCovered ShanghaiChina ADepartment of Neurology Fujan Medical University Union HospitalFuzhouChina Department of Neurology National Clinical Research Center for Geriatric DiseasesBeijingChina

Alzheimer's disease(AD)is a common cause of dementia,characterised by cerebral amyloid-βdeposition,pathological tau and *** prodromal stage of AD(pAD)refers to patients with mild cognitive impairment(MCl)and evidence of AD's *** this stage,disease-modifying interventions should be used to prevent the progression to *** the inherent heterogeneity of MCl,more specific biomarkers are needed to elucidate the underlying AD's *** the uses of cerebrospinal fluid and positron emission tomography are widely accepted methods for detecting AD's pathology,their clinical applications are limited by their high costs and invasiveness,particularly in low-income areas in ***,to improve the early detection of Alzheimer's disease(AD)pathology through cost-effective screening methods,a panel of 45neurologists,psychiatrists andgerontologistswas invited to establish a formal consensus on the screening of pAD in *** supportive evidence and grades of recommendations are based on a systematic literature review andfocus group *** meetings were held to allow participants to review,vote and provide their expert opinions to reach a consensus.A majority(two-thirds)decision was used for questions for which consensus could not be *** screening methods are presented in this publication,including neuropsychological assessment,peripheral biomarkers and brain *** addition,a general workflow for Screening pAD in China is established,which will help clinicians identify individuals at high risk and determine therapeutic targets.

关键词： Alzheimer income screening

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The electrical design of a membrane antenna for a lunar-based low-frequency radio telescope

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Astronomical Techniques and Instruments 2024年第4期1卷 227-238页

作者： Suonanben Fengquan Wu Kai He Shijie Sun Wei Zhou Minquan Zhou Cong Zhang Jiaqin Xu Qisen Yan Shenzhe Xu Jiacong Zhu Zhao Wang Ke Zhang Haitao Miao Jixia Li Yougang Wang tianlu chen Xuelei chen Key Laboratory of Cosmic Rays(Tibet University) Ministry of EducationLhasa 850000China Department of Physics College of ScienceTibet UniversityLhasa 850000China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Shanxi University Taiyuan 030000China School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China Center for Astronomy and Space Sciences China Three Gorges UniversityYichang 443002China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center of High Energy Physics Peking UniversityBeijing 100871China

Detecting primordial fluctuations from the cosmic dark ages requires extremely large low-frequency radio telescope arrays deployed on the far side of the *** antenna of such an array must be lightweight,easily storable and transportable,deployable on a large scale,durable,and capable of good electrical performance.A membrane antenna is an excellent candidate to meet these *** study the design of a low-frequency membrane antenna for a lunar-based low-frequency(<30 MHz)radio telescope constructed from polyimide film widely used in aerospace applications,owing to its excellent dielectric properties and high stability as a substrate *** first design and optimize an antenna in free space through dipole deformation and coupling principles,then simulate an antenna on the lunar surface with a simple lunar soil model,yielding an efficiency greater than 90%in the range of 12-19 MHz and greater than 10%in the range of 5-35 *** antenna inherits the omni-directional radiation pattern of a simple dipole antenna in the 5-30 MHz frequency band,giving a large field of view and allowing detection of the 21 cm global signal when used alone.A demonstration prototype is constructed,and its measured electrical property is found to be consistent with simulated results using|S11|*** membrane antenna can potentially fulfill the requirements of a lunar low-frequency array,establishing a solid technical foundation for future large-scale arrays for exploring the cosmic dark ages.

关键词： Membrane antenna Lunar-based radio array Cosmic dark ages

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Target recognition based on modified combination rule

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Journal of Systems Engineering and Electronics 2006年第2期17卷 279-283页

作者： chen tianlu Que Peiwen Inst. of Automatic Detection Shanghai Jiaotong Univ. Shanghai 200030 China

Evidence theory is widely used in the field of target recognition. The invalidation problem of this theory when dealing with highly conflict evidences is a research hotspot. Several alternatives of the combination rule are analyzed and compared. A new combination approach is proposed. Calculate the reliabilities of evidence sources using existing evidences. Construct reliabilities judge matrixes and get the weights of each evidence source. Weight average all inputted evidences. Combine processed evidences with D-S combination rule repeatedly to identify a target. The application in multi-sensor target reeognition as well as the comparison with typical alternatives all validated that this approach can dispose highly conflict evidences efficiently and get reasonable reeognition results rapidly.

关键词： evidence theory combination rule conflict evidences target recognition data fusion.

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星暴矮星系NGC 5253周围的中性氢气体分布

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中国科学院大学学报（中英文） 2024年第2期41卷 188-194页

作者：沃佳怡蔡肇伟左沛陈天禄西藏大学宇宙线教育部重点实验室拉萨850000 西藏大学理学院物理系拉萨850000 中国科学院国家天文台北京100101 中国科学院大学天文与空间科学学院北京101408 中国科学院FAST重点实验室北京100101 北京大学科维理天文与天体物理研究所北京100871

中性氢(HI)气体是恒星形成的基本物质,驱动着星系的演化。对于星暴矮星系NGC 5253,过去的研究利用射电干涉阵观测到的HI气体呈不对称分布,向东北方向延伸约7 kpc。这一延展结构可能表明NGC 5253与其附近的旋涡星系M 83之间存在动力学联... 详细信息

中性氢(HI)气体是恒星形成的基本物质,驱动着星系的演化。对于星暴矮星系NGC 5253,过去的研究利用射电干涉阵观测到的HI气体呈不对称分布,向东北方向延伸约7 kpc。这一延展结构可能表明NGC 5253与其附近的旋涡星系M 83之间存在动力学联系。为研究这两个星系之间可能存在的HI气体连接,从绿岸望远镜获得了射电L波段对NGC 5253周围的HI成图数据,探测到NGC 5253和M 83之间可能存在的7个HI气体云团。这些HI气体云团候选体主要分布在东北方向,由NGC 5253延展至距离超过60 kpc外。这些气体云团可能在触发矮星系NGC 5253剧烈的恒星形成活动中发挥重要作用。

关键词：星系相互作用恒星形成中性氢气体 NGC 5253

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空腹血糖升高与认知功能恶化的代谢关联研究

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上海交通大学学报（医学版） 2024年第2期44卷 212-222页

作者：吴丽蓉陈瑞华晁筱雯郭雨槐孙涛李梦慈陈天璐上海交通大学医学院附属第六人民医院转化医学中心上海200233 上海交通大学医学院附属第六人民医院样本库上海200233

目的·分析探讨空腹血糖(fasting blood glucose,FBG)升高人群中导致认知功能恶化的影响因素和导致认知功能恶化风险变化的代谢线索。方法·从阿尔茨海默病神经影像学计划数据库中下载阿尔茨海默病队列数据,并筛选出具有FBG数据和随访... 详细信息

目的·分析探讨空腹血糖(fasting blood glucose,FBG)升高人群中导致认知功能恶化的影响因素和导致认知功能恶化风险变化的代谢线索。方法·从阿尔茨海默病神经影像学计划数据库中下载阿尔茨海默病队列数据,并筛选出具有FBG数据和随访数据的样本,获得其临床资料[包括年龄、性别、身体质量指数、教育程度、载脂蛋白E4(apolipoprotein E4,APOE4)基因型、人种]和代谢指标数据(包括氨基酸、脂肪酸、蛋白质等)。根据受试者的FBG水平和认知障碍阶段诊断,将其分为正常FBG并无/有认知功能恶化组、FBG升高并无/有认知功能恶化组。采用单因素分析、Cox比例风险回归模型、正交偏最小二乘判别分析、Spearman相关性分析对数据进行分析。结果·共纳入1317例具有FBG数据且具有较为完整的临床资料与代谢物数据的受试者,其中FBG正常(>3.9 mmol/L且<6.1 mmol/L)共1153例,FBG升高(≥6.1 mmol/L)共164例。FBG正常的受试者中,275例有认知功能恶化;FBG升高的受试者中,53例有认知功能恶化。基线人口统计学特征分析结果显示,正常FBG组和高FBG组在性别、人种上差异有统计学意义,无认知功能恶化组和有认知功能恶化组在年龄、性别、APOE4基因携带率上差异有统计学意义(均P<0.05)。Cox回归分析表明,认知功能恶化的主要促进因素依次为APOE4基因阳性、FBG升高和年龄增长(HR=2.22,HR=1.38,HR=1.02;均P<0.05)。不同FBG水平下无认知功能恶化和有恶化组的基线代谢指标,以及认知功能恶化前与认知功能恶化后的代谢指标的差异分析结果显示:在认知功能恶化人群中,高密度脂蛋白(high-density lipoproteins,HDL)携带的磷脂在总脂质中的比值显著升高;低密度脂蛋白(low-density lipoprotein,LDL)颗粒浓度及其携带的脂质含量在认知功能恶化后显著升高。相关性分析结果显示,在认知功能恶化人群中,缬氨酸、亮氨酸不仅与FBG水平显著相关,还与血浆磷酸化tau蛋白(phosphorylated tau,pTau)水平显著相关;HDL携带的胆固醇含量、磷脂与总脂质的比值与脑脊液pTau水平显著相关。结论·相较于FBG正常的人群,FBG升高人群认知功能恶化风险显著增加;且不同FBG水平下,无认知功能恶化人群和有认知功能恶化的人群以及认知恶化前与认知恶化后显著差异的代谢指标有所不同。总体而言,LDL及其携带的脂质、HDL携带的磷脂在认知功能恶化过程中呈上升趋势,且支链氨基酸中的缬氨酸与亮氨酸与pTau水平有显著相关性,提示这几个代谢指标在认知功能恶化过程中或许起重要作用。

关键词：血糖升高认知障碍代谢组学危险因素脂蛋白

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Geminga TeV晕周围星际介质的湍动特性

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中国科学院大学学报（中英文） 2024年第3期41卷 306-311页

作者：程皓麟朱辉陈天禄田文武崔晓红吴丹高启西藏大学宇宙线教育部重点实验室拉萨850000 中国科学院国家天文台北京100101 西藏大学理学院物理系拉萨850000 中国科学院大学北京100049

空间功率谱分析是研究星际介质湍动特性的常用方法。以此方法利用GALFA HI巡天数据分析Geminga附近一块中性氢云的湍动特性,其21 cm谱线积分亮温度图的空间功率谱符合幂律分布,谱指数为-4.0±0.1。与银河系内本地星际介质的功率谱(谱指... 详细信息

空间功率谱分析是研究星际介质湍动特性的常用方法。以此方法利用GALFA HI巡天数据分析Geminga附近一块中性氢云的湍动特性,其21 cm谱线积分亮温度图的空间功率谱符合幂律分布,谱指数为-4.0±0.1。与银河系内本地星际介质的功率谱(谱指数大于-3.0)相比,该云的功率谱较陡。分析陡谱的成因,排除了中性氢云在视线方向所取的速度宽度不足、云周围存在垂直于视线方向的有序磁场、能量传递过程中有损失等因素的影响。这个结果暗示Geminga周围可能存在一个区域,其内部湍动特性与银河系其他区域的湍动特性不同,进而导致了Geminga TeV晕中较低的扩散系数。

关键词：星际介质湍动 Geminga 空间功率谱分析

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Effect of nano-CaO particle on the microstructure,mechanical properties and corrosion behavior of lean Mg-1Zn alloy

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Journal of Magnesium and Alloys 2024年第2期12卷 794-814页

作者： Guangxin Shen Shaoyuan Lyu Leiting Yu tianlu Li chen You Xuewei Wang Minfang chen Bin Jiang School of Materials Science and Engineering Tianjin University of TechnologyTianjin 300384China Key Laboratory of Display Materials and Photoelectric Device(Ministry of Education) Tianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Function Materials Education Tianjin University of TechnologyTianjin 300384China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

The effects of nano-CaO contents on the microstructure,mechanical properties and corrosion resistance of lean Mg-1Zn alloy were *** results showed that the addition of nano-CaO significantly refined the grain size and improved mechanical properties of the Mg-1Zn *** the same time,CaO reacted with molten Mg in situ to form nano-MgO,whose corrosion product in SBF solution was the same with the degradation product of Mg matrix,resulting in the enhanced compactness of the Mg(OH)_(2) layer and reduced corrosion rate of *** Mg-1Zn alloy had lower corrosion resistance due to excessively large grain size and shedding of corrosion *** composite with 0.5 wt.%CaO had the best corrosion resistance with a weight loss of 9.875 mg·y^(-1)·mm^(-2)due to the small number of Ca_(2)Mg_(6)Zn_(3) phase and suitable grain *** for composites with high content of CaO(0.7 wt.%and 1.0 wt.%),they had lower corrosion resistance due to the coexistence of large number of Ca_(2)Mg_(6)Zn_(3) and Mg_(2)Ca at grain boundaries,especially for 1.0 wt.%CaO composite,resulting from the strong micro-galvanic corrosion.

关键词： Lean Mg alloy In situ MgO Nanoparticles Grain refinement Corrosion resistance

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基于临界氮浓度稀释曲线的内蒙古土默川平原滴灌玉米氮营养诊断

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北方农业学报 2024年第3期52卷 1-18页

作者：郝琪梁红伟王永强王富贵陈天陆王振白岚方王志刚内蒙古农业大学农学院内蒙古呼和浩特010019 内蒙古自治区农牧业科学院内蒙古呼和浩特010031

【目的】明确氮肥运筹对内蒙古土默川平原滴灌玉米产量和氮素利用效率的影响,探讨以氮营养指数为监测指标诊断土默川平原滴灌水肥一体化玉米氮营养状况的可行性。【方法】检测2022—2023年内蒙古包头市土默特右旗、呼和浩特市土默特左... 详细信息

【目的】明确氮肥运筹对内蒙古土默川平原滴灌玉米产量和氮素利用效率的影响,探讨以氮营养指数为监测指标诊断土默川平原滴灌水肥一体化玉米氮营养状况的可行性。【方法】检测2022—2023年内蒙古包头市土默特右旗、呼和浩特市土默特左旗两试验地中3个施氮量(0、270、360 kg/hm^(2))和全生育期3次、5次施氮下玉米氮营养含量,采用方差分析和统计建模的方法,研究玉米的产量和氮素利用效率,分析各时期玉米冠层氮浓度和地上部生物量的变化规律并构建玉米临界氮浓度稀释曲线模型。【结果】增加施氮量和施氮次数能显著提高玉米穗数、穗粒数和千粒重进而提高产量,增加施氮次数能显著提高玉米氮素利用效率(P<0.05);施氮量从270 kg/hm^(2)增加至360 kg/hm^(2),年平均产量提高5.79%;施氮次数从3次增加至5次,年平均产量和年平均氮素利用效率分别提高3.15%、22.25%。土默川平原滴灌玉米临界氮浓度稀释曲线模型为Nc=3.36W^(-0.22),R^(2)=0.94,P<0.05,验证精度RMSE、NRMSE和MAE分别为0.40%、11.50%和0.20%,模型稳定性较好。通过模型计算,施氮量270 kg/hm^(2)时,对应适宜施氮次数为5次,分别在4叶展期、8叶展期、大喇叭口期、吐丝期和乳熟期以15∶25∶35∶15∶10的比例追施氮肥,玉米产量最优,为14.09 t/hm^(2);玉米拔节期、9叶展期、大喇叭口期、吐丝期和乳熟期需氮量范围分别为-3.42~15.29、-16.80~22.90、-26.86~62.32、-54.65~85.14和-48.18~111.80 kg/hm^(2)。【结论】适当增加施氮量和施氮次数能显著提高内蒙古土默川平原滴灌玉米产量和氮素利用效率,玉米临界氮浓度稀释曲线模型可以有效识别内蒙古土默川平原玉米拔节期到乳熟期植株氮营养状况,通过该模型还可以计算、推荐合适的施肥量,能够实现玉米生长的按需作业。

关键词：土默川平原滴灌玉米临界氮浓度稀释曲线氮营养指数需氮量

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