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Transient response of doubly-curved bio-inspired composite shells resting on viscoelastic foundation subject to blast load using improved first-order shear theory and isogeometric approach

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Defence Technology（防务技术） 2024年第8期38卷 171-193页

作者： thuy Tran thi thu Tu Nguyen anh Hue Nguyen thi Hong Nguyen thi School of Mechanical and Automotive Engineering Hanoi University of IndustryHanoiViet Nam Faculty of Technical Fundamental University of Transport TechnologyHanoiViet Nam Faculty of Mechanical Engineering Thuyloi University175 Tay SonDong DaHanoiViet Nam

Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.

关键词： Blast load Modified first-order shear theory Biological composite structures

越南广宁省私立汉语培训机构学习者学习现状调查及分析

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越南广宁省私立汉语培训机构学习者学习现状调查及分析

作者：梁降秋英（LUONG GIANG thu anh）大理大学

学位级别：硕士

随着经济的发展,中国早已成长为世界第二大经济体,越来越多的国家开始向往投入中国市场,与中国开展系列经济合作。越南与中国相接壤,与中国开展经济合作,推动越南经济发展具有天然的地理优势,再加上越南从古到今受到中国文化的熏陶,越... 详细信息

随着经济的发展,中国早已成长为世界第二大经济体,越来越多的国家开始向往投入中国市场,与中国开展系列经济合作。越南与中国相接壤,与中国开展经济合作,推动越南经济发展具有天然的地理优势,再加上越南从古到今受到中国文化的熏陶,越南全国上下已经掀起“汉语热”,甚至在公立学校、私立学校都开设了汉语课程,学习汉语的越南人也逐渐增多。除此之外,越来越多的以汉语教学为主的私立培训机构纷纷出现,已经形成产业,成为越南汉语教育的主力军之一。本文以越南广宁省私立培训机构中的汉语学习者为研究对象,集中对广宁省内的私立汉语培训机构开展研究,通过采用观察、问卷、访谈的方法,对广宁省私立汉语培训机构的学员、教师、机构整体进行全方位、多层次的研究和了解,并结合文献综述的方法,对调查结果进行梳理,明晰越南广宁省汉语教学情况,找到广宁省私立汉语培训机构存在的问题,并一一提出优化建议,希望为广宁省私立汉语培训机构的进一步发展,提升汉语教学质量提出有价值的建议。

关键词：越南广宁省私立培训机构汉语学习者

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

Fabrication and characterization of YVO_4:Eu^(3+) nanomaterials by the microwave technique

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Journal of Rare Earths 2011年第12期29卷 1137-1141页

作者： Tran thu Huong Vu Duc Tu Tran Kim anh Le thi Vinh Le Quoc Minh Institute of Materials Science Vietnamese Academy of Science and Technology University of Engineering and Technology National University Hanoi Departments of Chemistry Hanoi University of Mining and Geology

Fabrication and characterization of YVO4：Eu^3＋ nanophosphors prepared by microwave （MW） irradiation assisted soft template synthesis were reported. The effects of synthesis conditions such as different powers of MW irradiation, pH values and concentration of reac- tion materials on properties of nanophosphor were also investigated to obtain the controllable size, morphology and high luminescence efficiency. Morphology, crystalline structure, and optical properties were characterized by field emission scanning electron microscopy （FE-SEM）, X-ray diffraction （XRD） and fluorescence spectroscopy, respectively. The results showed that YVOa：Eu^3＋ nanophosphors were obtained by using diethyleneglycol （DEG） as soft template, with pH values in the range of 4 to 12, upon microwave irradiation from 300 to 900 W, at temperature of 80 ℃. The high fluorescent YVOa：Eu^3＋ nanocrystals obtained with size from 15 nm down to 8 nm are more effective to develop an ultrahigh sensitive fluorescent label for biomolecule, cell and tissue.

关键词： microwave synthesis method DEG soft template YVO4:Eu^3+ nanophosphor luminescence rare earths

Twin reversed arterial perfusion sequence-a rare and dangerous complication form of monochorionic twins:A case report

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World Journal of Clinical Cases 2022年第28期10卷 10214-10219页

作者： Nguyen Duy anh Nguyen-thi thu Ha Nguyen-thi Sim Nguyen Khac Toan Phan-thi Huyen thuong Nguyen Minh Duc Fetal Medicine Center Hanoi Obstetrics and Gynecology HospitalHanoi 100000Vietnam Department of Assisted Reproduction Hanoi Obstetrics and Gynecology HospitalHanoi 100000Vietnam Department of Obstetrics and Gynecology Hanoi University of Medicine and PharmacyHanoi 100000Vietnam Department of Radiology Pham Ngoc Thach University of MedicineHo Chi Minh City 700000Vietnam

BACKGROUND Twin reversed arterial perfusion(TRAP) sequence is an extremely rare congenital anomaly in monochorionic(MC) *** condition is characterized by a malformed fetus(acardiac twin) without cardiac activities being perfused by a structurally normal one(pump twin) via an artery-to-artery anastomosis in a reverse *** SUMMARY We described the first case of TRAP to receive laser surgery in *** 26-wk pregnancy was originally misdiagnosed in another hospital as MC twins with single intrauterine fetal *** admission to our center,the diagnosis was amended to a 26-wk TRAP sequence stage *** acardiac twin was 7.5 cm at the longest length,the ratio of the weight of the acardiac twin to the weight of the pump twin was more than 90%,the pump twin showed fetal distress with absent diastolic flow in umbilical artery of pump twin,and the peak systolic velocity in the middle cerebral artery = 1.6 Mo *** performed emergency laser photocoagulation of the acardiac twin’s umbilical *** surgery,we successfully maintained the pregnancy for 8 wk and ended it electively by cesarean section at 34 wk of gestation due to rupture of *** TRAP should be appropriately diagnosed and treated early to avoid complications of the pump *** laser photocoagulation is a new and effective treatment for this condition.

关键词： Twin reversed arterial perfusion Acardiac twin Pump twin Laser Case report

Physical activity and immunity in obese older adults:A systematic bibliographic analysis

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Sports Medicine and Health Science 2023年第3期5卷 181-189页

作者： Novita Intan Arovah Dang thi anh thu Juni Kurniawaty Hartiah Haroen Department of Sports Science Faculty of Sports ScienceUniversitas Negeri YogyakartaJalan Colombo No 1 KarangmalangYogyakarta55228Indonesia School of Science Faculty of Public HealthHue University of Medicine and Pharmacy06 Ngo QuyenVinh Ninh WardHue CityViet Nam Department of Anaesthesiology Faculty of MedicineUniversitas Gadjah MadaDepartemen Anestesiologi dan Terapi Intensif RSUP Dr.SardjitoJln.Kesehatan No.1SekipYogyakarta55231Indonesia Department of Nursing Faculty of NursingUniversitas PadjajaranHegarmanahKec.JatinangorKabupaten SumedangBandungJawa Barat45363Indonesia

Extensive research has been conducted on the roles of physical activity in immune ***,reviews on the effect of physical activity on immune function among obese older adults are *** study aimed to map the trend and development of the key terms and prominent sources to identify potential research opportunities through a systematic bibliographic analysis.A systematic search was conducted in the Scopus database on the following query:(sport^(*)OR“physical activity”OR exercise)AND(elderly OR“older adult^(*)”OR aging)AND(immun^(*))AND(obes^(*))AND NOT(animal),in March *** timing and citation were descriptively analyzed,followed by the bibliographic coupling and the term co-occurrence analyses for generating network and overlay visualization mapping using the VOSviewers *** search resulted in 426 articles dating back from 1991 to the present and were dominated by authors from Western *** thematic clusters of this research area were generated,covering(1)the impact of physical activity or inactivity on health,(2)physical activity assessments and the use of association and cross-sectional study as the primary type of research,and(3)the physical activity impacts at the population *** future research,more intervention studies are needed to understand how exercise affects immune response in older obese adults and to explore optimal duration,type,and intensity of the exercise,using a multi-omics *** in non-Western populations and systematic reviews are recommended to complement this bibliographic analysis.

关键词： Aging Exercise Sports Obesity Immune responses

Synthesis and characterization of core/shell structured nanophosphors CePO_4:Tb@LaPO_4 by solvothermal method

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Journal of Rare Earths 2011年第12期29卷 1147-1151页

作者： Dinh Xuan Loc Tran thi Kim Chi Tran thu Huong Nguyen Vu Tran Kim anh Wieslaw Strek Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology Institute of Low Temperature and Structure Research Polish Academy of Sciences(PAN) University of Engineering and Technology

Core/shell structured CePO4：Tb（Ⅲ）@LaPO4 and CePOa：Tb（Ⅲ） were successfully synthesized in tris（2-ethylhexyl） phosphate （TEHP） and diethylene glycol （DEG） solvents for comparison of the two techniques in open air and closed reaction vessel. Morphology and crystal structure of the core/shell nanophosphors were determined by using X-ray diffraction （XRD） and transmission electron microscopy （TEM）, which showed that nanophosphors had diameter of about 5-10 nm with the monoclinic monazite phase. The nanophosphors obtained by close vessel procedure showed smaller size, more homogeneity and pure crystallite. The luminescent measurements were done upon the different excitation wavelengths in ultraviolet region and at room temperatm＇e to elucidate the influences of the used solvents and the reaction temperatures. It was found that CePO4：Tb@LaPO4 preparedby the close vessel synthesis showed the intensity of green band of the transfer from 5D4 to 7F5 energy level, which was strongly increased, and the luminescent decay time was 3.2 ms, which was longer than that of naked CePO4：Tb phosphor.

关键词： solvothermal synthesis luminescence CePOn:Tb CePOa:Tb@LaPO4 rare earths

草酸促进双酚A在黏土矿物悬浮液中光降解研究

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环境科学学报 2009年第12期29卷 2585-2590页

作者：刘延湘 Vu thi thu anh 吴峰江汉大学化学与环境工程学院武汉430056 越南科学与技术院海洋地质与地球物理研究所河内100803 武汉大学资源与环境学院武汉430072

选择两种常见的天然黏土矿物高岭石和蒙脱石,研究了有机污染物双酚A(BPA)在其表面的吸附及草酸对黏土矿物悬浮液中BPA光降解的影响.结果表明,BPA在两种黏土矿物表面的吸附量较小,吸附符合Langmuir等温式.在250W金属卤化物灯(λ≥360nm)... 详细信息

选择两种常见的天然黏土矿物高岭石和蒙脱石,研究了有机污染物双酚A(BPA)在其表面的吸附及草酸对黏土矿物悬浮液中BPA光降解的影响.结果表明,BPA在两种黏土矿物表面的吸附量较小,吸附符合Langmuir等温式.在250W金属卤化物灯(λ≥360nm)照射下,草酸可显著促进BPA在高岭石和蒙脱石悬浮液中的光降解,降解动力学符合Langmuir-Hinshelwood方程.降解速率受pH值的影响较大,pH=4.0时速度最快,光降解速率同时受草酸浓度的影响.最后,通过分析矿物中铁的化学环境及反应过程中铁浓度变化,分析了草酸促进BPA在黏土矿物悬浮液中光降解的可能机制.

关键词：草酸双酚A 天然高岭石天然蒙脱石光降解

New guidelines for fluorophore application in peroxisome targeting analyses in transient plant expression systems

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Journal of Integrative Plant Biology 2019年第7期61卷 884-899页

作者： Christian Falter Nguyen Binh anh thu Saugat Pokhrel Sigrun Reumann Plant Biochemistry and Infection Biology Institute of Plant Science and Microbiology University of Hamburg

Peroxisome research has been revolutionized by proteome studies combined with in vivo subcellular targeting analyses. Yellow and cyan fluorescent protein(YFP and CFP) are the classical fluorophores of plant peroxisome research. In the new transient expression system of Arabidopsis seedlings co-cultivated with Agrobacterium we detected the YFP fusion of one candidate protein in peroxisomes, but only upon co-transformation with the peroxisome marker, CFP-PTS1. The data suggested that the YFP fusion was directed to peroxisomes due to its weak heterodimerization ability with CFP-PTS1,allowing piggy-back import into peroxisomes. Indeed, if co-expressed with monomeric Cerulean-PTS1(mCer-PTS1),the YFP fusion was no longer matrix localized. We systematically investigated the occurrence and extent of dimerization-based piggy-back import for different fluorophore combinations in five major transient plant expression systems. In Arabidopsis seedlings and tobacco leaves both untagged YFP and monomeric Venus were imported into peroxisomes if co-expressed with CFP-PTS1 but not with mCer-PTS1. By contrast, piggy-back import of cytosolic proteins was not observed in Arabidopsis and tobacco protoplasts or in onion epidermal cells for any fluorophore combination at any time point. Based on these important results we formulate new guidelines for fluorophore usage and experimental design to guarantee reliable identification of novel plant peroxisomal proteins.

关键词： transient plant expression systems fluorophore