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Autohydrolysis treatment of bamboo and potassium oxalate(K_(2)C_(2)O_(4))activation of bamboo product for CO_(2) capture utilization

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 63-72页

作者： Dang Duc Viet Doan thi thao Khuong Duy Anh Toshiki Tsubota Department of Materials Science Faculty of EngineeringKyushu Institute of TechnologyFukuoka 804-8550Japan Vietnamese Academy of Forest Sciences Hanoi 10000Vietnam Collaborative Research Centre for Green Materials on Environmental Technology Kyushu Institute of TechnologyFukuoka 808-0196Japan

Typically,the hydroxide agents,such as sodium hydroxide and potassium hydroxide,which have corrosive properties,are used in the carbon activation *** this study,potassium oxalate(K_(2)C_(2)O_(4)),a less toxic and non-corrosive activating reagent,was used to synthesize activated carbon from the solid residue after autohydrolysis *** effect of the autohydrolysis treatment and the ratio of the K_(2)C_(2)O_(4)/solid residue are presented in this ***,the comparison between the activated carbon from bamboo and biochar from the solid residue are also *** resulting activated carbon from the solid residue exhibited a high surface area of up to 1432 m^(2)·g^(-1) and a total pore volume of up to 0.88 cm^(3)·g^(-1).The autohydrolysis treatment enhanced the microporosity properties compared to those without pretreatment of the activated *** microporosity of the activated carbon from the solid residue was dominated by the pore width at 0.7 nm,which is excellent for CO_(2) *** 25℃ and 1.013×10^(5) Pa,the CO_(2) captured reached up to 4.1 mmol·g^(-1).On the other hand,the ratio between K_(2)C_(2)O_(4) and the solid residue has not played a critical role in determining the porosity *** ratio of the K_(2)C_(2)O_(4)/solid residue of 2 could help the carbon material reach a highly microporous textural property that produces a high carbon capture *** finding proved the benefit of using the solid residue from the autohydrolysis treatment as a precursor material and offering a more friendly and sustainable activation carbon process.

关键词： activated carbon bamboo biochar CO_(2)capture potassium oxalate

Prevalence and risk factors associated with long COVID symptoms in children and adolescents in a southern province of Vietnam

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Asian Pacific Journal of Tropical Medicine 2024年第3期17卷 119-128,I0001,I0002页

作者： Huynh Ngoc Linh Nguyen The Tan Le thi Minh Thu Nguyen Tu Loan Nguyen thi To Uyen Le Thanh thao Trang Truong Thanh Nam Doan hoang Phu Faculty of Medicine Ca Mau Medical CollegeCa Mau 98000Vietnam Ca Mau Obstetrics and Pediatrics Hospital Ca Mau 98000Vietnam Faculty of Basic Science and Public Health Dong Thap Medical CollegeDong Thap 81000Vietnam Graduate University of Sciences and Technology Vietnam Academy of Science and TechnologyHa Noi 10000Vietnam Community Public Health Research Program School of Public HealthWalailak UniversityNakhon Si Thammarat 80160Thailand Faculty Public Health Can Tho University of Medicine and PharmacyCan Tho City 94000Vietnam Doctoral Program in Health Sciences College of Graduate StudiesWalailak UniversityNakhon Si Thammarat 80160Thailand

Objective:To investigate the prevalence and risk factors associated with long COVID symptoms among children and adolescents who have recovered from ***:this study applied a cross-sectional approach within community settings in a southern province of Vietnam.A structured questionnaire featuring socio-demographic information and common long COVID symptoms was *** correlation coefficients assessed associations among pairs of long COVID ***,multivariable logistic regression models were performed to investigate the risk factors of long COVID in recovered COVID-19 children and ***:Among 422 participants,39.3%reported long COVID symptoms,with a prevalence of 45.2%(SD=0.5)in children and 22.2%(SD=0.4)in *** symptoms reported were cough 34.6%(SD=0.5),fatigue 20.6%(SD=0.4),shortness of breath 10.9%(SD=0.3),and lack of appetite 6.6%(SD=0.3).Concerning risk factors of long COVID,a higher risk was observed among demographic groups,including girls(OR 1.25,95%CI 1.15-1.37;Pthis study provide crucial guidance for predicting the factors associated with the occurrence of long COVID in pediatric patients,contributing to strategic interventions aimed at mitigating the long COVID risks among children and adolescents in Vietnam.

关键词： Long COVID Prevalence Risk factors Children Adolescent Vietnam

Influence of different land-use types on selected soil properties related to soil fertility in A Luoi District,Thua thien Hue,Vietnam

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Soil Ecology Letters 2024年第1期6卷 131-140页

作者： Khoa Phuc Nguyen Tan Trong Tran Huy Dinh Le Phuong Thuy Nguyen Hien thao thi Pham Dien Thanh Nguyen Ngu Huu Nguyen University of Agriculture and Forestry Hue UniversityHue CityThua Thien Hue 52000Vietnam School of Biotechnology Tan Tao UniversityTan Duc ECityDuc HoaLong An850000Vietnam

Land use type affects the physicochemical properties of *** value of OM and TN is high in acacia *** acidity of soil is considered a serious constraint for *** cash crops are acacia,cassava,banana,rice and *** fertility is affected by land-use types and land management,which exacerbates soil erosion and various other forms of soil degradation in the mountainous regions of *** study was conducted in A Luoi District,Thua thien Hue,Vietnam to identify the effects of land-use types on specific soil physicochemical characteristics related to soil *** physicochemical properties,such as organic matter(OM),total nitrogen(TN),total phosphorous(TP),and K+were significantly affected by land-use *** results showed that the soils were sandy in rice but clay loam for acacia and *** mean bulk density value of acacia soil was significantly greater than that of other *** were higher in the acacia soils than those in the rice,maize,and banana *** OM content was significantly higher in the acacia,cassava,and banana soils than those in the rice and maize *** mean of exchangeable K+in the rice soil was higher compared to those in other soils and was affected by land-use *** high exchangeable acidity content in the soils was probably due to intensive ***,both land use type and management did not affect the CEC ***,the inappropriate land use caused the disturbance of soil physicochemical properties,indicating that the conditions of rice and maize soils are becoming worse than acacia ***,lowering the intensity of cultivation,adopting incorporated soil fertility management,and applying organic fertilizer should preserve the existing conditions and enhance soil properties.

关键词： Land-use types soil characteristics soil frility suitable crop Vietnam

越南初级非汉语专业学习者汉语口语自我效能与口语成绩的相关性研究

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越南初级非汉语专业学习者汉语口语自我效能与口语成绩的相关性研...

作者：陈氏芳草（TRAN thi PHUONG thao）广西大学

学位级别：硕士

初中级越南汉语学习者状态补语习得偏误研究及建议 ——以胡志明市师范大学中文系为例

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初中级越南汉语学习者状态补语习得偏误研究及建议 ——以胡志明...

作者：陈氏清草（Tran thi Thanh thao）河北大学

学位级别：硕士

补语是中文语法中的一个重要知识点,也是一个相对难的语法学习点,特别是对于越南学习者,因为在越南语中没有相似的结构,所以对于他们来说补语的难度更大。中文有着丰富而复杂的补语系统,其中,状态补语在汉语中使用频率高、结构复杂、语... 详细信息

补语是中文语法中的一个重要知识点,也是一个相对难的语法学习点,特别是对于越南学习者,因为在越南语中没有相似的结构,所以对于他们来说补语的难度更大。中文有着丰富而复杂的补语系统,其中,状态补语在汉语中使用频率高、结构复杂、语义繁多、语境因素强,被汉语教学界视为汉语教学的重点和难点。笔者是越南留学习者,也曾经经历过汉语学习初中级这段时间,因此特别理解初中级汉语学习者习得过程中的困难与学习过程中的需求。本文主要收集了越南胡志明市师范大学中文系初中级汉语学习者在使用汉语状态补语时产生的偏误,并进行了详细的偏误研究和分析。通过调查与分析,笔者旨在找出更科学有效的汉语状态补语教学方法。本文先对研究背景、研究目的和意义、研究方法等进行说明,对状态补语的语料搜集情况进行概述,本文选择《HSK标准教材2、3》中的状态补语为考察对象,以偏误分析理论、中介语理论和对比分析理论为指导,并采用调查分析、个别访谈等方法进行研究。其次对国际中文教学中的状态补语进行研究综述与相关界定,主要总结了状态补语的本体研究和国际中文教学中的状态补语研究,分析了状态补语研究现状。笔者还对初中级越南学习者的调查问卷和试题进行整理和分析,主要针对胡志明市师范大学中文系的初中级学习者,通过调查问卷与访谈进行状态补语偏误语料的搜集与统计。第四部分对初中级越南学习者学习状态补语的偏误进行了分类,共分为五类。随后,对初中级越南学习者学习汉语状态补语产生偏误的原因进行了分析,分为客观因素和主观因素,并探讨了学习者们回避状态补语学习的现象及其原因。最后是对状态补语的教学思考,针对引起偏误的原因提出具体的教学建议,并设计了部分教学计划,同时提供了《HSK标准教程1、2、3》中状态补语动词相关的参考例句和练习。希望本文研究成果能为越南初中级汉语语法教学提供启示,并能在实际教学中提高教学效果、降低学习难度、减轻教学压力,从而找到最佳的汉语状态补语教学途径。同时,也期望本研究能够为国际中文教学和研究贡献一份力量。

关键词：初中级越南学习者状态补语习得偏误

Localized Exponential Time Differencing Method for Shallow Water Equations: Algorithms and Numerical Study

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Communications in Computational Physics 2021年第1期29卷 80-110页

作者： Xucheng Meng thi-thao-Phuong hoang Zhu Wang Lili Ju Department of Mathematics University of South CarolinaColumbiaSC 29208USA Department of Mathematics and Statistics Auburn UniversityAuburnAL 36849USA SUSTech International Center for Mathematics Southern University of Science and TechnologyShenzhenGuangdong 518055China Center for Mathematical studies Advanced Institute of Natural SciencesBeijing Normal University at ZhuhaiZhuhaiGuangdong 519087China

In this paper,we investigate the performance of the exponential time differencing(ETD)method applied to the rotating shallow water *** with explicit time stepping of the same order accuracy in time,the ETD algorithms could reduce the computational time in many cases by allowing the use of large time step sizes while still maintaining numerical *** accelerate the ETD simulations,we propose a localized approach that synthesizes the ETD method and overlapping domain *** dividing the original problem into many subdomain problems of smaller sizes and solving them locally,the proposed approach could speed up the calculation of matrix exponential vector *** standard test cases for shallow water equations of one or multiple layers are *** results show great potential of the localized ETD method for high-performance computing because each subdomain problem can be naturally solved in parallel at every time step.

关键词： Exponential time differencing domain decomposition rotating shallow water equa-tions finite volume discretization

Synthesis and characterization of NaYF4:Yb3+,Er3+@silica-N=folic acid nanocomplex for bioimaginable detecting MCF-7 breast cancer cells

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Journal of Rare Earths 2019年第11期37卷 1183-1187页

作者： Ha thi Phuong Tran Thu Huong Le thi Vinh hoang thi Khuyen Do thi thao Nguyen Thanh Huong Pham thi Lien Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Graduate University of Science and Technology-Vietnam Academy of Science and Technology 18 Hoang Quoc VietCau GiayHanoiViet Nam Department of Chemistry Hanoi Medical University1-Ton That TungDong DaHanoiViet Nam Department of Chemistry Hanoi University of Mining and Geology18-Pho LienBac Tu LiemHanoiViet Nam Institute of Biotechnology Vietnam Academy of Science and Technology18-Hoang Quoc VietCau GiayHanoiViet Nam Duy Tan University K7/25 Quang TrungDa NangViet Nam

Upconversion nanophosphors are new promising nanomaterials to be used as biolabels for detection and imaging of cancer *** nanophosphors absorb long-wavelength excitation radiation in the infrared or near infrared region and emit shorter wavelength,higher energy radiation from ultraviolet to *** this paper,we studied the hydrothermal method and optical properties of the functionalized NaYF4:Yb^3+,Er^3+for biomedical *** synthesis,these NaYF4:Yb^3+,Er^3+nanophosphors were functionalized with aminosilanes and folic *** acid binds to the folate receptor on the surface of MCF-7 breast cancer cells and this binding promotes internalization of the nanophosphors via *** sizes of the functionalized NaYF4:Yb^3+,Er^3+@silica-N=FA(folic acid)nanophosphors can be controlled with length of the rod about 300-800 nm and diameter of the rod about 100-200 *** structure of NaYF4:Yb^3+,Er^3+is in hexagonal crystal *** photo luminescence(PL)spectra of the functionalized NaYF4:Yb^3+,Er^3+@silica-N=FA nanophosphors were *** nanophosphors emit in red color with the strongest band at 650 nm under 980 nm *** result can provide NaYF4:Er^3+,Yb^3+@silica-N=FA complex for developing fluorescence label and image tool in cancer biology and medicine.

关键词： Upconversion luminescence NaYF4:Yb^3+,Er^3+ Nanophosphors Bioimaging Cancer cell Rare earths

Operator Splitting and Local Time-Stepping Methods for Transport Problems in Fractured Porous Media

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Communications in Computational Physics 2023年第10期34卷 1215-1246页

作者： Phuoc-Toan Huynh Yanzhao Cao thi-thao-Phuong hoang Department of Mathematics and Statistics Auburn UniversityAuburn 36849AlabamaUSA

this paper is concerned with efficient numerical methods for the advectiondiffusion equation in a heterogeneous porous medium containing fractures.A dimensionally reduced fracture model is considered,in which the fracture is represented as an interface between subdomains and is assumed to have larger permeability than the surrounding *** develop three global-in-time domain decomposition methods coupled with operator splitting for the reduced fracture model,where the advection and the diffusion are treated separately by different numerical schemes and with different time ***,smaller time steps can be used in the fracture-interface than in the *** first two methods are based on the physical transmission conditions,while the third one is based on the optimized Schwarz waveform relaxation approach with Ventcel-Robin transmission conditions.A discrete space-time interface system is formulated for each method and is solved iteratively and globally in *** results for two-dimensional problems with various P′eclet numbers and different types of fracture are presented to illustrate and compare the convergence and accuracy in time of the proposed methods with local time stepping.

关键词： Domain decomposition reduced fracture model operator splitting nonconforming time grids time-dependent Steklov-Poincare operator optimized Schwarz waveform relaxation

Successful containment of a COVID-19 outbreak in Bach Mai Hospital by prompt and decisive responses

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Asian Pacific Journal of Tropical Medicine 2021年第5期14卷 234-235页

作者： Van Minh hoang thi Phuong thao Tran thi Ngoc Phuong Nguyen thi Hai Yen Nguyen Quang Tuan Nguyen Hanoi University of Public Health HanoiVietnam Bach Mai Hospital HanoiVietnam

In low-and middle-income countries,tertiary care hospitals frequently face an extremely heavy workload and shoulder an even heavier burden during the COVID-19 *** Mai Hospital(BMH),one of the leading tertiary hospitals in Vietnam,is on the frontline in the fierce battle against *** letter aims to describe how BMH tackles the COVID-19 outbreak in the hospitallevel battle,which could support policymakers in time-management and well-preparation for this unpredictable pandemic.

关键词： prompt income policy