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Growth of the tropical Pinus kesiya as influenced by climate and nutrient availability along an elevational gradient

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Journal of Plant Ecology 2020年第1期13卷 97-106页

作者： le tuan Ho Raimund Schneider Frank M.Thomas Department of Geobotany University of TrierFaculty of Regional and Environmental SciencesBehringstraße 2154296 TrierGermany Department of Forest Resources Management Faculty of ForestryNong Lam University HCMCThu Duc DistrictHo Chi Minh CityVietnam Department of Soil Science University of TrierFaculty of Regional and Environmental SciencesBehringstraße 2154296 TrierGermany

与温带地区相比,人们对在热带山脉中,尤其是热带针叶林中,沿海拔梯度的个体树种生长减少的原因知之甚少。我们的研究目的是检验气候或土壤条件是否会导致在高海拔分布的卡西亚松(Pinus kesiya,一种在南亚和东南亚广泛分布的松树)的生长... 详细信息

与温带地区相比,人们对在热带山脉中,尤其是热带针叶林中,沿海拔梯度的个体树种生长减少的原因知之甚少。我们的研究目的是检验气候或土壤条件是否会导致在高海拔分布的卡西亚松(Pinus kesiya,一种在南亚和东南亚广泛分布的松树)的生长减少。我们对越南中南部山脉中沿海拔梯度约在900~2000米之间的卡西亚松的树干直径增量和其年轮中^(13)C(△^(13)C)的同位素判别进行分析。同时确定其生长与△^(13)C、气候和土壤变量的关系。研究发现,树木的断面积生长量(BAI)与温度或降水之间没有一致的相关关系。相反,沿海拔梯度,我们发现BAI与△^(13)C以及与上层矿质土壤的C/N比和δ^(15)N特征呈显著负相关。BAI与土壤中有效磷(P_(a))和“碱性”阳离子(钙、镁、钾)的浓度呈正相关。我们的结论是,较高海拔下的较低温度会对树木生长产生间接影响,主要通过产生较高的C/N比并降低氮(N)和P矿化率而产生作用,而这些影响因其他负面反馈而进一步受到阻碍。主要包括:降水增加的淋溶作用而导致较低浓度的“碱性”阳离子以及较高海拔土壤矿化的N和P的有效性降低。本研究结果可以进一步解释卡西亚松的最高生长极限以及该物种在其他山区出现的情况。

关键词：树木生态学松树指示年土壤养分稳定同位素

Nutritional status of Vietnamese infants assessed by Fenton growth chart and related factors:A cross-sectional study

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Pediatric Investigation 2023年第4期7卷 254-262页

作者： Lieu Thu Thi Nguyen Cuong Danh Tran Ha Thu Thi Nguyen Hai Thanh Phan Linh Thuy Nguyen Huong Lan Thi Nguyen anh Hoai Thi Ta Chau Quynh Thi Pho Khanh Nam Do anh Kim Dang Huong Thi le School of Preventive Medicine and Public Health Hanoi Medical UniversityHanoiVietnam Department of Nutrition National Hospital of Obstetrics and GynecologyHanoiVietnam Department of General Obstetrics National Hospital of Obstetrics and GynecologyHanoiVietnam Department of Nutrition and Dietetics Hanoi Medical University HospitalHanoiVietnam Queensland Alliance for Environmental Health Sciences(QAEHS) The University of QueenslandBrisbaneAustralia

Importance:Nutritional status of infants,measured by birth weight and length,is an essential factor in neonatal *** in newborns may lead to a higher risk of mortality,neurological and cognitive impairment,and poor language ***:This study aims to assess the nutritional status of infants and related factors regarding maternal anthropometric characteristics and medical ***:A cross-sectional study was conducted at the National Hospital of Obstetrics and Gynecology,Vietnam from May 2021 to May 2022 on 340 infants and *** birth weight was defined following the Intergrowth-21 *** was evaluated using the Fenton growth chart when the length was below the 10%percentile line of the gestational *** regression models were applied to identify factors associated with the nutritional status of ***:We found that 12.4%and 14.1%of infants in our study fell into stunted and underweight categories,*** of mothers over 35 years old,having a height lower than 150 cm or experiencing anemia during pregnancy were more likely to be stunted or have low birth *** albumin deficiency during pregnancy was strongly associated with the infant being underweight(odds ratio[OR]=2.8,95%confidence interval[95%CI]1.1–7.3).Newborns were more likely to be stunted if their mothers had a history of preterm birth(OR=3.3,95%CI 1.1–10.2).Interpretation:Maternal nutritional status is closely related to infant malnutrition,particularly in preterm *** the understanding of mothers regarding prenatal care,reproductive healthcare,adequate nutritional diet,and multi-micronutrient supplements during pregnancy is therefore important.

关键词： Fenton chart Infant Low birth weight Stunting Underweight

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

Examining unobserved factors associated with red light running in Vietnam:A latent class model analysis

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Transportation Safety and Environment 2022年第1期4卷 110-122页

作者： Tien Dung Chu Tomio Miwa tuan anh Bui Quang Phuc Nguyen Quang Huy Vu Department of Highway and Traffic Engineering University of Transport and CommunicationsNo.3 Cau Giay StreetLang Thuong WardDong Da DistrictHanoi 10001Vietnam Institute of Materials and Systems for Sustainability Nagoya UniversityFuro-choChikusa-kuNagoya cityAichi Prefecture464-8603Japan

Red-light running(RLR)is a crucial violation that causes traffic accidents and *** factors that affect RLR is very significant to reduce the potential of this *** studies have paid considerable attention to the observable factors,but not to unobservable *** study aims to examine the effects of observable and unobservable factors on *** study uses a latent class model(LCM)to assign individuals into two classes—red-light-respectful and red-light-disrespectful road users—by surveying 751 respondents who use private transportation *** study incorporates psychological determinants into the LCM to account for unobservable *** contribution of this study is the in-depth investigation into law-respectful and law-disrespectful behaviours and intentional and unintentional *** a study has not yet been conducted in the existing *** addition,a comprehensive comparison of the LCM and a traditional ordered probit model was ***,the results suggest that the LCM is superior to the model that does not consider latent *** estimation results are in alignment with previous studies on RLR:males,younger drivers/riders,less educated road users and motorcyclists are more likely to run red *** analysis of the latent variables shows that surrounding conditions—the behaviour of other violators,the absence of traffic police,and long waiting times—increase the possibility of *** on these results,we provide suggestions to policymakers and traffic engineers:the implementation of enforcement cameras and penalties for violators are critical countermeasures to minimize the potential of RLR.

关键词： red light running(RLR) developing country latent class model(LCM) multiple indicator multiple cause(MIMIC)model latent variables(LVs) motorcycles(MCs) traffic violation

Fabrication and properties of high efficiency luminescent nanorods EuPO_4·H_2O by soft template method

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Journal of Rare Earths 2011年第12期29卷 1174-1177页

作者： Tran Thu Huong Tran Kim anh le Thi Vinh W.Strek Hoang Thi Khuyen le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology Department of Chemistry Hanoi University of Mining and Geology Institute of Low Temperature and Structure Research University of Engineering and Technology National University Hanoi

Europium orthophosphate monohydrate （EuPO4·H2O） nanorods with typical dimensions of about 10-30 nm in diameter and 300-500 nm in length were prepared by using the soft template method. The effects of using diethylene glycol （DEG） and polyethylene glycol （PEG） polymers as well as the pH values on the size, crystalline structure and morphology of EuPO4·H2O nanorods were investigated. Field emission scanning electron microscopy （FESEM） and X-ray diffraction （XRD） data of the prepared samples were elucidated. The nanorods were highly uniform and their mean length was reduced by using DEG and PEG as soft template agents. For all prepared samples, the rhabdophanetype hexagonal EuPO4·H2O was the dominated phase. The photoluminescence （PL） spectroscopy measurements of EuPO4·H2O nanorods revealed that, under UV excitation, EuPO4·H2O nanorods exhibited strong luminescence with narrow bands corresponding to the intra-4f transitions of ^5D0→^7Fj （j=1, 2, 3, 4） of Eu^3＋ ions. The peaks were found at 594 nm （^5D0→^7F1）, 619 nm （^5D0→^7F2）, 652 nm （^5D0→^7F3）, and 697 nm （^5D0→^7F4）, with the strongest emission at 594 nm.

关键词： soft template method EuPO4·H2O nanorods fluorescence rare earths

Preliminary Study of Photometric Redshifts Based on the Wide Field Survey Telescope

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Research in Astronomy and Astrophysics 2023年第12期23卷 138-152页

作者： Yu Liu Xiao-Zhi Lin Yong-Quan Xue Huynh anh N.le CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

The Wide Field Survey Telescope(WFST)is a dedicated time-domain multi-band(u,g,r,i,and z)photometric survey facility under *** this paper,we present a preliminary study that assesses the quality of photometric redshifts based on WFST by utilizing mock observations derived with the galaxy catalog in the COSMOS/UltraVISTA *** apply the template fitting technique to estimate photometric redshifts by using the ZEBRA photometric-redshift code and adopting a modified set of adaptive *** evaluate the bias(median relative offset between the output photometric redshifts and input redshifts),normalized median absolute deviation(σ_(NMAD))and outlier fraction(f_(outlier))of photometric redshifts in two typical WFST observational cases,the single 30 s exposure observations(hereafter shallow mode)and co-added 50 minutes exposure observations(hereafter deep mode).We find bias≲0.006,σ_(NMAD)≲0.03,and f_(outlier)≲5%in the shallow mode and bias≈0.005,σ_(NMAD)≈0.06,and f_(outlier)≈17%–27%in the deep mode,respectively,under various lunar *** the WFST mock observational data with that from the upcoming CSST and Euclid surveys,we demonstrate that the zphot results can be significantly improved,with f_(outlier)≈1%andσ_(NMAD)≈0.02.

关键词： galaxies distances and redshifts-galaxies high-redshift-galaxies photometry

Contributions of Rotation,Expansion and Line Broadening to the Morphology and Kinematics of the Inner CSE of Oxygen-rich AGB Star R Hya

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Research in Astronomy and Astrophysics 2023年第1期23卷 40-47页

作者： Pham Tuyet Nhung Do Thi Hoai Pierre Darriulat Pham Ngoc Diep Nguyen Bich Ngoc Tran Thi Thai Pham tuan-anh Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa NoiVietnam

We use archival ALMA observations of the CO(2-1)and SiO(5-4)molecular line emissions of AGB star R Hya to illustrate the relative contributions of rotation,expansion and line broadening to the morphology and kinematics of the circumstellar envelope(CSE)within some~70 au(~0."5)from the centre of the *** give evidence for rotation and important line broadening to dominate the inner region,within~14 au(~100 mas)from the centre of the *** former is about an axis that projects a few degrees west of north and has a projected rotation velocity of a few km s^(-1).The latter occurs within some 7-14 au(50-100 mas)from the centre of the star,with the line width reaching two to three times its value outside this *** suggest that it is caused by shocks induced by stellar pulsations and convective cell *** show the importance of properly accounting for the observed line broadening when discussing rotation and evaluating the radial dependence of the rotation velocity.

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

Dealing with the Class Imbalance Problem in the Detection of Fake Job Descriptions

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Computers, Materials & Continua 2021年第7期68卷 521-535页

作者： Minh Thanh Vo anh H.Vo Trang Nguyen Rohit Sharma Tuong le Faculty of Information Technology Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh CityVietnam Faculty of Information Technology Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Information Technology Ho Chi Minh City Open UniversityHo Chi Minh CityVietnam Department of Electronics&Communication Engineering SRM Institute of Science and TechnologyNCR CampusGhaziabadIndia Informetrics Research Group Ton Duc Thang UniversityHo Chi Minh CityVietnam

In recent years,the detection of fake job descriptions has become increasingly necessary because social networking has changed the way people access burgeoning information in the internet *** fraud in job descriptions can help jobseekers to avoid many of the risks of job ***,the problem of detecting fake job descriptions comes up against the problem of class imbalance when the number of genuine jobs exceeds the number of fake *** causes a reduction in the predictability and performance of traditional machine learning *** therefore present an efficient framework that uses an oversampling technique called FJD-OT(Fake Job Description Detection Using Oversampling Techniques)to improve the predictability of detecting fake job *** the proposed framework,we apply several techniques including the removal of stop words and the use of a tokenizer to preprocess the text data in the first *** then use a bag of words in combination with the term frequency-inverse document frequency(TF-IDF)approach to extract the features from the text data to create the feature dataset in the second ***,our framework applies k-fold cross-validation,a commonly used technique to test the effectiveness of machine learning models,that splits the experimental dataset[the Employment Scam Aegean(ESA)dataset in our study]into training and test sets for *** training set is passed through the third module,an oversampling module in which the SVMSMOTE method is used to balance data before training the classifiers in the last *** experimental results indicate that the proposed approach significantly improves the predictability of fake job description detection on the ESA dataset based on several popular performance metrics.

关键词： Fake job description detection class imbalance problem oversampling techniques

An Efficient Viewport-Dependent 360 VR System Based on Adaptive Tiled Streaming

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Computers, Materials & Continua 2021年第3期66卷 2627-2643页

作者： tuan Thanh le Jong-Beom Jeong Sang Soon lee Jaehyoun Kim Eun-Seok Ryu Department of Computer Engineering Gachon UniversitySeongnam13120Korea Department of Computer Education Sungkyunkwan UniversitySeoul03063Korea

Recent advances in 360 video streaming technologies have enhanced the immersive experience of video streaming ***,there is immense potential for the application of 360 video encoding formats to achieve highly immersive virtual reality(VR)***,360 video streaming requires considerable bandwidth,and its performance depends on several ***,the optimization of 360 video bitstreams according to viewport texture is ***,we propose an adaptive solution for VR systems using viewport-dependent tiled 360 video *** increase the degrees of freedom of users,the moving picture experts group(MPEG)recently defined three degrees plus of freedom(3DoF+)and six degrees of freedom(6DoF)to support free user movement within camera-captured *** proposed method supports 6DoF to allow users to move their heads ***,we propose viewport-dependent tiled 360 video streaming based on users’head *** proposed system generates an adaptive bitstream using tile sets that are selected according to a parameter set of user’s viewport *** extracted bitstream is then transmitted to the user’s *** decoding,the user’s viewport is generated and rendered on VR head-mounted display(HMD).Furthermore,we introduce certain approaches to reduce the motion-to-photon *** experimental results demonstrated that,in contrast with non-tiled streaming,the proposed method achieved high-performance 360 video streaming for VR systems,with a 25.89%BD-rate saving for Y-PSNR and 61.16%for decoding time.

关键词： Virtual reality 360 video MPEGimmersive 6DoF MCTS viewportdependent