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Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests

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Journal of Forestry Research 2020年第5期31卷 1713-1722页

作者： Tran Van Do Mamoru Yamamoto Osamu Kozan Vo Dai Hai Phung Dinh Trung Nguyen Toan Thang Lai Thanh Hai Vu Thanh Nam Trieu Thai Hung hoang Van Thang Tran Duc Manh Cao Chi Khiem Vu Tien Lam Nguyen Quang Hung Tran hoang Quy Pham Quang Tuyen Trinh Ngoc Bon Nguyen thi Thu Phuong Ninh Viet Khuong Nguyen Van Tuan Dang thi Hai Ha Tran Hai Long Dang Van Thuyet Dang thinh Trieu Nguyen Van thinh Tran Anh Hai Duong Quang Trung Nguyen Van Bich Dinh Hai Dang Pham Tien Dung Nguyen Huy hoang Le thi Hanh Phan Minh Quang Nguyen thi Thuy Huong hoang Thanh Son Nguyen Thanh Son Nguyen thi Van Anh Nguyen thi Hoai Anh Pham Dinh Sam hoang thi nhung hoang Van Thanh Nguyen Huu thinh Tran Hong Van Ho Trung Luong Bui Kieu Hung Research Institute for Sustainable Humanosphere Kyoto UniversityUjiKyotoJapan Silviculture Research Institute Vietnamese Academy of Forest SciencesNorth Tu LiemHanoiVietnam Center for Southeast Asian Studies Kyoto UniversityKyotoJapan Vietnamese Academy of Forest Sciences North Tu LiemHanoiVietnam Vietnam Administration of Forestry No.2 Ngoc HaBa DinhHanoiVietnam

Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest *** study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was *** results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of *** area and AGB are positively correlated with trees>30 cm *** areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-*** percent of the areas surveyed had stand densities of 300–600 ***^-1,and 64%had basal areas of 20–40 m^2 ha^-*** is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in *** causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density.

关键词： Aboveground biomass Carbon storage Climatic variables Ecoregion Edaphic variables Oldgrowth forest

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中越会计准则比较研究

中越会计准则比较研究

作者：黄氏红绒（hoang thi Hong nhung）重庆理工大学

学位级别：硕士

经济全球化推动了资本市场全球化,投资者需要具有国际可比性和透明度的会计信息,这就要求世界各国都采用可比性高的会计标准,进而产生了会计准则等技术标准的区域趋同和国际趋同。目前,很多国家在制定本国会计准则时都会参考国际会计准... 详细信息

经济全球化推动了资本市场全球化,投资者需要具有国际可比性和透明度的会计信息,这就要求世界各国都采用可比性高的会计标准,进而产生了会计准则等技术标准的区域趋同和国际趋同。目前,很多国家在制定本国会计准则时都会参考国际会计准则和国际财务报告准则(IAS和IFRS)。无论是全部采用国际会计准则还是制定具备国际趋同特征的本国会计准则,都将有助于使本国的会计准则或技术标准更加完善。中越两国是邻国,同属东方文化体系,在经济制度、社会国情等方面均具有共同点,经贸合作前景巨大。因此,探索中国会计准则(CAS)与越南会计准则(VAS)之间的差异和趋同程度,不仅有利于两国投资者深入理解对方的会计准则,也有利于两国会计准则的协调。本文的结构安排如下:第一章为绪论,包括研究背景、问题与文献综述等;第二章介绍中越两国会计准则的发展历程和现状;第三章是中越两国会计准则的总体比较分析;第四章是中越两国具体会计准则存在的差异分析;第五章是越南会计准则的国际化与国家协调;第六章是结论与展望。通过分析发现:(1)虽然中、越两国的会计改革都在走国际趋同的道路,基本准则的制定也都借鉴了国际会计准则概念框架的内容,但由于受本国的经济和法律环境的影响,仍然存在差异。比如:为满足会计信息客观性与相关性的质量要求,中国采用多种计量属性,而越南只有历史成本一种计量属性。(2)具体会计准则中,中国规定无形资产的取得方式有企业自行开发、外购、投资者投入、债务重组、政府补助、合并和非货币性资产交换;越南会计准则规定无形资产的取得方式包括单项购买、有期限土地使用权、国家拨给或赠予、并购购买的、换入和自行开发。对比发现,越南比中国少了投资者投入和债务重组两种取得无形资产的方式。(3)在固定资产方面,两国在确认条件、成本构成、后续计量方面(包括增值税、非货币性资产交换业务取得资产、资产放置处理)都存在一些差异。(4)在会计报告方面,中、越两国大同小异,这与两国的经济发展和社会环境的异同有一定关系。

关键词：越南会计准则中国会计准则比较分析会计趋同

Comparative Chemical Research in Essential Oils from Six Apiaceae Species Growing in the Northern Region of Vietnam

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1677-1687页

作者： Nguyen Quang Hung Nguyen Thanh Tung Nguyen Phuong Hanh Chu thi Thu Ha Nguyen thi nhung Nguyen Thai An Vu Xuan Giang Luong Van Hao Oleh Koshovyi Ain Raal Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology(VAST)Cau GiayHa Noi100000Viet Nam Graduate University of Science and Technology Vietnam Academy of Science and Technology(VAST)Cau GiayHa Noi100000Viet Nam Department of Pharmacognosy Faculty of Pharmacognosy and Traditional MedicineHanoi University of PharmacyHoan KiemHa Noi100000Viet Nam Sa Pa Research Center of Medicinal Materials National Institute of Medicinal MaterialsDien Bien PhuSa PaLao Cai330000Viet Nam Institute of Pharmacy Faculty of MedicineUniversity of TartuTartu50411Estonia

Our study aimed to compare the essential oil(EO)concentration and composition of several Apiaceae species growing in the Northern region of *** yields of EOs from materials ranged from 0.03%(root EO of Angelica acutiloba and aerial parts EO of Heracleum bivittatum)-0.27%(leaf EO of Xyloselinum vietnamense).Gas chromatography-mass spectrometry(GC-MS)allowed the identiﬁcation of 74 components in the EOs of six Apiaceae species,making up 94.4%–100.0%of the *** EO from Angelica acutiloba,(Z)-ligustilide accounted for an extremely large proportion(94.9%).EO of Angelica pubescens was dominated by six character-istic components includingα-pinene(21.5%),β-phellandrene(18.1%),p-cymene(12.2%),3-methylnonane(8.7%),o-cymene(8.1%),and D-sylvestrene(6.2%).The EO from Cryptotaenia japonica was characterized by high amounts ofα-selinene(48.7%),β-selinene(23.7%),and trans-β-farnesene(5.4%).The EOs from leaves and stems of Xyloselinum vietnamense were characterized by high concentrations of sabinene(69.8%and 33.8%),4-terpineol(8.7%and 7.4%)andβ-pinene(4.0%and 6.5%)while EOs from aerial parts and root of Xylo-selinum leonidii comprise four characteristic monoterpenes includingα-pinene(28.2%and 52.8%),β-pinene(7.9%and 10.3%),β-phellandrene(7.6%and 15.3%),and sabinene(3.0%and 4.1%).Additionally,cryptone is also one of the major components in the EO of Xyloselinum leonidii(13.2%in the aerial parts oil and 2.8%in the root oil).In the EOs isolated from the aerial parts and root of Heracleum bivittatum,α-pinene(22.5%and 70.2%)andβ-pinene(43.2%and 20.0%)were the predominant *** appeared in the EO from aerial parts of Heracleum bivittatum with a relatively high concentration(13.5%)while bornyl acetate(5.1%)was also one of the main components in the EO from its aerial parts but was not detected in other Apiaceae species in the present *** databases help identify and control the quality of plant material studied from the family Apiaceae growing in Vietnam.

关键词： Apiaceae essential oil terpenoids gaschromatography-mass spectrometry

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越南中学语文教材中的中华经典教学研究

越南中学语文教材中的中华经典教学研究

作者：阮氏红绒（thi Hong nhung Nguyen）扬州大学

学位级别：硕士

EP Aquarii:A New Picture of the Circumstellar Envelope

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Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： Pham T.nhung Do T.Hoai Pierre Darriulat Pham Tuan-Anh Pham N.Diep Nguyen B.Ngoc Tran T.Thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

关键词： stars AGB and post-AGB-(stars) circumstellar matter-radio lines stars

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