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Morphology and kinematics of the gas envelope of the Mira binary W Aquilae

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Research in Astronomy and Astrophysics 2016年第7期16卷 47-54页

作者： Do thi Hoai Pham Tuyet Nhung Pham Ngoc Diep nguyen thi Phuong Pham Tuan-Anh nguyen thi thao Pierre Darriulat Department of Astrophysics Vietnam National Satellite CenterVAST

We analyse ALMA observations of the12CO（3-2） emission of the circumstellar envelope（CSE）of the Mira variable binary star W Aql. These provide, for the first time, spatially resolved Doppler velocity spectra of the CSE up to angular distances to the central star ofy nature of the observations（only five minutes in each of～5′′（meaning some 2000 AU）. The explorator two different configurations） does not allow for a detailed modelling of the properties of the CSE but provides important qualitative information on its morphology and kinematics. Emission is found to be enhanced along an axis moving from east/west to north-east/south-west when the angular distance from the central star projected on the plane of the sky increases from zero to four arcseconds. In parallel, the Doppler velocity distribution displays asymmetry along an axis moving from east/west to north-west/south-east. The results are discussed in the context of earlier observations, in particular of the dust morphology.

关键词： stars AGB and post-AGB (stars ) circumstellar matter stars individual(W Aql) stars mass-loss radio lines stars

^(12)CO emission from the Red Rectangle

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Research in Astronomy and Astrophysics 2015年第12期15卷 2213-2228页

作者： Pham Tuan Anh Pham Ngoc Diep Do thi Hoai Pham Tuyet Nhung nguyen thi Phuong nguyen thi thao Pierre Darriulat Department of Astrophysics Vietnam National Satellite CenterVAST

Observations of an unprecedented quality made by ALMA on the Red Rectangle of CO（3-2） and CO（6-5） emissions are analysed jointly with the aim of obtaining as simple as possible a description of the gas morphology and kinematics. Evidence is found for polar conical outflows and for a broad equatorial torus in rotation and expansion. Simple models of both are proposed. Comparing CO（6-5） and CO（3-2） emissions provides evidence for a strong temperature enhancement over the polar outflows. Continuum emission （dust） is seen to be enhanced in the equatorial region. Observed asymmetries are briefly discussed.

关键词： stars: AGB and post-AGB -- circumstellar matter -- radio-lines: stars-- planetary nebulae: individual (Red Rectangle)

Morphology and kinematics of the gas envelope of the variable AGB star π^1 Gruis

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Research in Astronomy and Astrophysics 2016年第7期16卷 97-104页

作者： Pham Tuyet Nhung Do thi Hoai Pham Ngoc Diep nguyen thi Phuong nguyen thi thao Pham Tuan Anh Pierre Darriulat Department of Astrophysics Vietnam National Satellite CenterVAST

Observations of the ^12CO（3–2） emission from the circumstellar envelope（CSE） of the variable star π1Gru using the compact array of the ALMA observatory have been recently made accessible to the public. An analysis of the morphology and kinematics of the CSE is presented with a result very similar to that obtained earlier for ^12CO（2–1） emission using the Submillimeter Array. A quantitative comparison is made using their flared disk model. A new model is presented that provides a significantly better description of the data, using radial winds and smooth evolutions of the radio emission and wind velocity from the stellar equator to the poles.

关键词： stars AGB and post-AGB circumstellar matter star individual(π1Gru) stars massloss radio lines stars

ALMA observations of the circumstellar envelope around EP Aqr

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Research in Astronomy and Astrophysics 2019年第3期19卷 97-110页

作者： Pham thi Tuyet Nhung Do thi Hoai Pham Tuan-Anh thibaut Le Bertre Pierre Darriulat Pham Ngoc Diep nguyen thi Phuong nguyen thi thao Jan Martin Winters Department of Astrophysics Vietnam National Space CenterVAST LERMA UMR 8112 CNRS and Observatoire de Paris PSL Research University Graduate University of Science and Technology VAST IRAM 300 rue de la Piscine Domaine Universitaire

Atacama Large Millimetre/sub-millimetre Array(ALMA) observations of CO(1–0) and CO(2–1) emissions from the circumstellar envelope of the asymptotic giant branch(AGB) star EP Aqr have been made with four times better spatial resolution than previously available. They are analysed with emphasis on the de-projection in space of the effective emissivity and flux of matter using as input a prescribed configuration of the velocity field, assumed to be radial. The data are found to display an intrinsic axisymmetry with respect to an axis making a small angle with respect to the line of sight. A broad range of wind configurations, from prolate(bipolar) to oblate(equatorial) has been studied and found to be accompanied by significant equatorial emission. Qualitatively, the effective emissivity is enhanced near the equator to produce the central narrow component observed in the Doppler velocity spectra and its dependence on star latitude generally follows that of the wind velocity with the exception of an omni-present depression near the poles. In particular, large equatorial expansion velocities produce a flared disc or a ring of effective emissivity and mass loss. The effect on the determination of the orientation of the star axis of radial velocity gradients, and possibly competing rotation and expansion in the equatorial disc, is discussed. In general,the flux of matter is found to reach a broad maximum at distances of the order of 500 AU from the *** are given that may be used to favour one wind velocity distribution over another. As a result of the improved quality of the data, a deeper understanding of the constraints imposed on morphology and kinematics has been obtained.

关键词： stars: AGB and post-AGB (stars:) circumstellar matter stars: individual: EP Aqr stars:mass-loss radio lines: stars

Gravitationally lensed extended sources: the case of QSO RXJ0911

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Research in Astronomy and Astrophysics 2013年第7期13卷 803-814页

作者： Do thi Hoai Pham Tuyet Nhung Pham Tuan Anh Frederic Boone Pierre Darriulat Pham Ngoc Diep Pham Ngoc Dong nguyen Van Hiep nguyen thi thao VATLY INST179Hoang Quoc VietCau GiayHanoiVietnam IRAP 14avenue Edouard BelinF31400 ToulouseFrance

After a brief reminder of the mechanism of gravitational lensing of ex- tended sources, the particular case of the host galaxy of QSO RXJ0911, a high red-shift （z - 2.8） quadruply imaged quasar, is explored. The non linearity of the problem, together with the proximity of the source to a cusp of the lens inner caustic, has impor-tant consequences on the dependence of the image appearance on the size and shape of the source. Their expected main features and their interpretation in terms of source extension and shape are investigated in a spirit of simplicity and in preparation for the analysis of high sensitivity and spatial resolution images that will soon be within reach with the completion of the Atacama Large Millimeter/submillimeter Array （ALMA）. In particular, the information on source size carded by relative image brightness is dis-cussed. Extension of the results to other types of quadruply imaged quasars is briefly considered.

关键词： gravitational lensing - galaxies: high-redshift

Morphology of the ^(13)CO(3–2) millimetre emission across the gas disc surrounding the triple protostar GG Tau A using ALMA observations

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Research in Astronomy and Astrophysics 2018年第3期18卷 63-76页

作者： nguyen thi Phuong Pham Ngoc Diep Anne Dutrey Edwige Chapillon Pierre Darriulat Stéphane Guilloteau Do thi Hoai Pham Tuyet Nhung Ya-Wen Tang nguyen thi thao Pham Tuan-Anh Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology Graduate University of Science and Technology Vietnam Academy of Science and Technology Laboratoire d’Astrophysique de Bordeaux Université de Bordeaux IRAM F-38406 Saint Martin d’Hères Cedex Academia Sinica Institute of Astronomy and Astrophysics

Observations by the Atacama Large Millimetre/sub-millimetre Array of the dust continuum and ^13 CO（3–2） millimetre emissions of the triple stellar system GG Tau A are analysed,giving evidence for a rotating gas disc and a concentric and coplanar dust ring. The present work complements an earlier analysis（Tang et al.） by exploring detailed properties of the gas disc. A 95% confidence level upper limit of 0.24＂（34 au） is placed on the disc scale height at a distance of 1＂（140 au） from the central stars. Evidence for Keplerian rotation of the gas disc is presented,with the rotation velocity reaching-3.1 km s^-1 at 1＂ from the central stars,and a 99% confidence level upper limit of 9% is placed on relative contribution from a possible in-fall velocity. Variations of the intensity across the disc area are studied in detail and confirm the presence of a hot spot in the south-eastern quadrant. However several other significant intensity variations,in particular a depression in the northern direction,are also revealed. Variations of the intensity are found to be positively correlated to variations of the line width. Possible contributions to the measured line width are reviewed,suggesting an increase of the disc temperature and opacity with decreasing distance from the stars.

关键词： protoplanetary disks - stars low-mass - stars individual (GG Tau A)

中国手机品牌形象对越南大学生购买倾向的影响因素实证研究

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中国手机品牌形象对越南大学生购买倾向的影响因素实证研究

作者： nguyen thi thao 华南理工大学

学位级别：硕士

如今,沟通是人类生活中最重要和最不可或缺的需求之一。而手机是一种帮助人们快速捕获信息及其了解周围世界的工具。之前,我们使用手机只为了拨打电话或写短信。现如今,智能手机已经彻底的改变了以前那些单一的使用方式。游戏、社交网... 详细信息

如今,沟通是人类生活中最重要和最不可或缺的需求之一。而手机是一种帮助人们快速捕获信息及其了解周围世界的工具。之前,我们使用手机只为了拨打电话或写短信。现如今,智能手机已经彻底的改变了以前那些单一的使用方式。游戏、社交网络、电子邮件、天气预报、地图和搜索等是常见的智能手机基本功能。移动网络已经实现了巨大的增长,这也是得益于智能手机的广泛使用。书籍、音乐、视频和新闻是当今移动用户最关心的事情。可以说,智能手机或智能手机的推出是满足这些需求的重大发明,每一个人都对智能手机的使用消费已经是大势所趋。随着社会不断地发展,21世纪的消费者有越来越来高的购买需求。在对手机的选择中,影响消费者的决定取决于诸多因素,因为市场上的信息来源提供了消费者多种多样的选择。再说,企业想要征服今天的市场,它规模不仅仅是在国内,而且还要有跨国发展的潜力。作为中国近邻的越南市场,对智能手机的消费需求十分巨大,特别是对于年轻追求时尚的越南大学生来说,他们对智能手机的市场需求巨大,他们也非常在意所使用的手机品牌形象,一定程度上影响到他们购买手机的倾向。近年来,中国以华为、小米、OPPO等手机品牌在国际市场上不断获得消费者的肯定,特别是以中国华为手机品牌为代表的手机品牌运营商,在手机技术方面不断进步,逐渐缩短与国外三星、苹果等手机品牌的距离。越南大学生是中国手机品牌消费的引导军,他们对手机品牌形象十分注重,开发好这个市场,才能够更好地获得越南其他消费者的认可。本文以越南大学生为调查调查,通过模型构建、研究假设、研究设计及调研设计,构建了4个主要变量及6个假设,对中国手机品牌对越南大学生购买倾向影响进行实证分析,通过相关性及回归分析,对假设进行验证,主要得出以下几点结论:中国手机品牌形象三个维度正向影响越南大学生的购买倾向;中国手机企业形象正向影响产品或服务形象;中国手机企业形象和产品或服务形象正向影响使用者形象。研究得到的几点对中国手机品牌企业在越南市场进行营销的启示有:注重塑造清晰的产品或服务形象;注重树立清晰的企业形象;注重品牌支持者培养。

关键词：品牌形象购买倾向企业形象

The Outcome of 40 Patients Becoming Pregnancy after Conservative Treatment of Cesarean Scar Pregnancy

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Case Reports in Clinical Medicine 2020年第12期9卷 376-384页

作者： nguyen Hong Hoa nguyen thi Thanh thao Hoang thi Diem Tuyet Van Phung Thong Department of Obstetrics & Gynecology Faculty of Medicine University of Medicine and Pharmacy at Ho Chi Minh City Ho Chi Minh City Vietnam Department of Obstetrics Hung Vuong Hospital Ho Chi Minh City Vietnam Department of Obstetrics Tu Du Hospital Ho Chi Minh City Vietnam

Background: The rate of uterus is successfully conserved following the treatment of scar pregnancy which is high so pregnancy outcome following caesarean scar ectopics is getting more and more attention. Objectives: To assess pregnancy course and outcome after conservative treatment of cesarean scar pregnancy. Methods: A retrospective case series of 40 patients become pregnancy after conservative treatment of cesarean scar pregnancy by Foley or Methotrexate and aspiration. Patients in present study were treated at Hung Vuong and Tu Du Hospital between 2015 and 2017. A telephone follow-up was conducted after cesarean scar pregnancy (CSP) treatment. The outcomes of these subsequent pregnancies and mode of delivery were all recorded. Results: In 40 pregnancies, there are 22 cases of intrauterine pregnancy with childbirth (55%);all babies were born healthy, with no complications recorded in pregnancy. 12 Women had recurrent scar ectopic (30%). There were 2 abortion cases, 2 cases of ectopic pregnancy, and 2 cases of early miscarriage. Conclusions: Our study shows that reproductive outcomes following treatment of caesarean scar ectopic pregnancies are favourable. The risk of recurrent caesarean scar ectopic pregnancy is a concern.

关键词： Caesarean Scar Pregnancy Reproductive Outcomes

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越南学生学习汉语声母的障碍及克服方法

越南学生学习汉语声母的障碍及克服方法

作者： nguyen thi thao（阮氏草）西北大学

学位级别：硕士

立足于越南留学生学习汉语声母时的难点与障碍,文章考察了越南留学生学习声母时的发音、听音、辨音问题并提出了相应的解决办法。在语音知识和教学理论的指导下,文章对汉语和越南语作了简单的比较性分析,在此基础上分析了越南学生语音... 详细信息

立足于越南留学生学习汉语声母时的难点与障碍,文章考察了越南留学生学习声母时的发音、听音、辨音问题并提出了相应的解决办法。在语音知识和教学理论的指导下,文章对汉语和越南语作了简单的比较性分析,在此基础上分析了越南学生语音学习上的难点,并且考察了难点之所以存在的原因。具体而言,文章重点研究了b、p、d、t、k、z、c、zh、ch, sh、r、j、q、x这十五个声母的发音、听音与辨音问题。首先,列举了越南学生学习上述十五个声母时的障碍;其次,分析了障碍形成的原因;最后,尝试性提出了克服障碍的方法。

关键词：学习障碍偏误分析克服策略