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Effect of Poly-Alkylene-Glycol Quenchant on the Distortion, Hardness, and Microstructure of 65Mn Steel

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Computers, Materials & Continua 2021年第6期67卷 3249-3264页

作者： Thi Xuan tran Xuan phuong Nguyen Duong Nam Nguyen Dinh Toai Vu Minh Quang Chau Osamah Ibrahim Khalaf Anh Tuan Hoang Hanoi University of Science and Technology HanoiVietnam Ho Chi Minh City University of transport Ho Chi Minh CityVietnam Vietnam Maritime University HaiphongVietnam Industrial University of Ho Chi Minh City(IUH) Ho Chi Minh CityVietnam Al-Nahrain Nanorenewable Energy Research Center Al-Nahrain UniversityBaghdadIraq Ho Chi Minh city University of Technology(HUTECH) Ho Chi Minh CityVietnam

Currently,the 65Mn steel is quenched mainly by oil *** though the lower cooling rate of oil compared to water reduces the hardness of steel post quenching,the deforming and cracking of parts are often *** the other hand,the oil media also has the disadvantage of being ammable,creating smoke that adversely affects the *** poly alkylene glycol(PAG)polymer quenchant is commonly used for quenching a variety of steels based on its advantages such as non-ammability and exible cooling rate subjected to varying concentration and stirring *** article examines the effect of PAG polymer quenching solution(with concentrations of 10%and 20%)on deformation,hardness,and microstructure of C-ring samples made of 65Mn ***,the performance of PAG polymer quenchant is also compared with those of two common quenching solutions:Water and *** cooling in water,the C-ring samples had the largest deformation and 2 times higher than the results obtained when a 10%PAG solution was *** particular,similar levels of deformation on the C-ring samples were observed in both cases of 20%PAG solution and oil as the primary quenching ***,the hardness level measured between the sampled parts quenched in the 20%PAG solution appeared to be more uniform than that obtained from the oil-quenched *** study of the microscopic structure of steel by optical microscopy combined with X-ray diffraction showed that the water hardened sample exhibited cracks and comprised of two phases,martensite and retained *** to the results of Electron Back Scattering Diffraction(EBSD)analysis and backscattering electronic image(BSE),the content of austenite residue in the sample when the sample was cooled in PAG 10 and 20%solution was 3.21%and 4.73%,respectively and smaller than the measurements obtained from oil quenching ***,the 65Mn steel is cooled in 20%PAG solution for high hardness and more evenly distributed than when it is q

关键词： Polyethylene glycol electron backscattering diffraction quenching media cooling rate backscattering electronic image

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

Thermodynamic Simulation on the Change in Phase for Carburizing Process

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Computers, Materials & Continua 2021年第7期68卷 1129-1145页

作者： Anh Tuan Hoang Xuan phuong Nguyen Osamah Ibrahim Khalaf Thi Xuan tran Minh Quang Chau Thi Minh Hao Dong Duong Nam Nguyen Ho Chi Minh city University of Technology(HUTECH) HoVietnam Ho Chi Minh city University of transport Ho Chi Minh cityVietnam Al-Nahrain University Al-Nahrain Nanorenewable Energy Research CenterBaghdadIraq Hanoi University of Science and Technology HanoiVietnam Industrial University of Ho Chi Minh City(IUH) Ho Chi Minh cityVietnam Vietnam Maritime University HaiphongVietnam

The type of technology used to strengthen the surface structure of machine parts,typically by carbon-permeation,has made a great contribution to the mechanical engineering industry because of its outstanding advantages in corrosion resistance and enhanced mechanical and physical ***,carbon permeation is considered as an optimal method of heat treatment through the diffusion of carbon atoms into the surface of alloy *** study presented research results on the thermodynamic calculation and simulation of the carbon permeability *** Fick’s law,the paper calculated the distribution of carbon concentration in the alloy steel after it is absorbed from the surface into the internal of the *** the SYSWELD software,an analysis was performed on the carbon permeability process to determine the distribution of carbon concentrations in 20CrMo steel that was then followed by a detailed analysis of the microstructure of the sample post the carburizing *** to the calculation results,the surface carbon content was 0.9%and steadily decreased into the *** 3 hours,the depth of the absorbent layer was measured at 0.5 mm for both the cylindrical and cubic *** analyzing the phase,the distribution of martensite phases such as ferrite/pearlite and residual austenite was also determined after the carburizing process.

关键词： Carburizing process 20CrMo steel thermodynamic analysis microstructure formation carbon concentration

越南媒体中两岸关系图景研究——以《VnExpress》为例

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越南媒体中两岸关系图景研究——以《VnExpress》为例

作者： HOANG THI phuong thao 厦门大学

学位级别：硕士

两岸关系是当前大陆和台湾较为迫切的问题,在一定程度上会直接或间接影响到两岸与其他国家的关系。因此、对两岸关系进行研究有着重要意义。笔者对前人的研究结果进行梳理发现:1.从媒体的角度对两岸关系进行研究大多为大陆学者和台湾学... 详细信息

两岸关系是当前大陆和台湾较为迫切的问题,在一定程度上会直接或间接影响到两岸与其他国家的关系。因此、对两岸关系进行研究有着重要意义。笔者对前人的研究结果进行梳理发现:1.从媒体的角度对两岸关系进行研究大多为大陆学者和台湾学者,越南学者的研究几乎没有,而从越南媒体视角看两岸关系更是一个空白点。2.研究对象集中在传统媒体,研究新媒体的文献很少。3.以往研究主要是以大陆和台湾媒体的视角看待两岸关系,或多或少会不够客观。本论文将以越南媒体为研究对象。基于框架理论,选择越南阅读量最高的电子报——《VnExpress》从2014年到2017年所有涉及两岸关系的报道作为研究样本。通过内容分析法对其报道数量、报道议题、消息来源以及报道倾向进行整体分析,并深入描述《VnExpress》在国际关系、政治、军事、社会、经济五大方面所建构的两岸关系图景。通过研究发现1.报道数量在201.6年猛增,其主要集中在七月和十二月。2.《VnExpress》中以两岸关系作为核心问题的报道占据最大比例,其关注点主要在两岸的国际关系、政治和军事三大方面,呈现出复杂国际关系、变动的政治局面以及动荡不安的军事图景。3.《VnExpress》的信息来源大多是来自于外国主流媒体。4.从整体看报道倾向以中立为主,细致分析发现在针对两岸相关的报道中,内容比例以台湾地区的相关内容为主,对于大陆地区的内容篇幅占较少比例。越南媒体承认“一个中国”原则,在涉及台湾地区的相关报道中会以非官方词语进行报道,例如对中国大陆越南媒体会用“中国政府”、“中国外交部”等词语。但是对于台湾,越南媒体则把其视为地区,并采用“台湾当局”、“台湾外交机构”等词语代替。

关键词：两岸关系内容分析 VnExpress

RASSFIA Promoter Hypermethylation as a Prognosis and Diagnosis for Breast Cancer in Vietnamese Population

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Journal of Life Sciences 2014年第4期8卷 316-321页

作者： Truong Kim phuong Lao Duc Thuan Doan Thi phuong thao Le Huyen Ai Thuy Falculty of Biotechnology Ho Chi Minh City Open University Ho Chi Minh City 70000 Vietnam Falculty of Medicine Ho Chi Minh City Medical University Ho Chi Minh City 70000 Vietnam

Aberrant tumor suppressor gene promoter methylation was associated with the several cancers, including breast cancer, which was the common female deaths in most countries involved in Vietnam. The methylation in tumor suppressor genes, including RASSFIA, were the key targets of establishing the potential biomarkers for prognosis and early diagnosis of breast cancer. In present study, with the aim towards using the hypermethylation at CpG islands of promoter of RASSFIA as the biomarker for breast cancer in Vietnamese population, MSP （methyl specific PCR） was carried out to analyze the hypermethylation status ofRASSFIA gene in 115 samples including 95 breast cancer specimens and 20 normal breast tissues from another disease （not breast cancer）. All samples were obtained from Ho Chi Minh City Medical Hospital, Vietnam. The known predictive and prognostic factors： HER2/neu overexpression was immunohistochemistry stained as input value for breast cancer specimens. For input value confirmed, the overexpression of p53 protein was also analyzed together with prior immunochemical assay. The results indicated that the hypermethylation of frequencies for methylation of given gene reached 42.1% （P 〈 0.05）. In addition, the DNA hypermethylation of RASSFIA gene increased the possibility to be breast cancer with high incidence via calculated of odd ratio （P 〈 0.05）. In conclusion, the hypermethylation of candidate genes could be used as the promising biomarkers applying in Vietnamese breast cancer patients.

关键词： RASSFIA hypermethylation MSP bisulfite modification breast cancer.

Effects of Sowing Time on the Growth, Development and Productivity of Sweet Sorghum

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Journal of Sustainable Bioenergy Systems 2015年第4期5卷 127-135页

作者： Hoang Thi Bich thao tran Van Dien tran Dang Xuan Thai Nguyen University of Agriculture and Forestry Thai Nguyen City Vietnam Graduate School for International Development and Cooperation (IDEC) Hiroshima University Hiroshima Prefecture Japan

The experiments were conducted to determine suitable sowing time in order to achieve high plant biomass and sugar content of sweet sorghum for bioethanol manufacture. The results showed that germination rate reached > 80% in all trial times (p > 0.05). The growth and development speed of sweet sorghum reduced when seeds were sowed in August and was significantly different from other sowing times (p < 0.05). Sowing from March to June obtained the highest plant height during all growth and development stages. Lodging and diseases observed in all periods of sowing, and planting began in July and August had lower percentage. In contrast, the productivity of fresh weight (1310.4 g/whole plant), sugar content (14.9% Brix), biomass yield (122.4 tons/ha) and theoretical converted ethanol yield (5 tons/ha) were the highest when sweet sorghum planted from March to June. It was observed that sowing sweet sorghum in four periods of month from March to June had the desirable biomass for bioethanol production.

关键词： Bioethanol Biomass Sowing Sugar Content Sweet Sorghum

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越南旅游业中国游客市场开发策略研究

越南旅游业中国游客市场开发策略研究

作者： PHAM THI phuong thao（范氏芳草）上海工程技术大学

学位级别：硕士

随着中国经济的发展,中国游客赴越南旅游人数呈现增长趋势。中国作为越南最大的客源国,对于越南的旅游产业有着很大的影响。为促进更多中国游客赴越南旅游,制定有效的开发策略具有十分重要的意义。本文的研究内容主要分为以下几部分:首... 详细信息

随着中国经济的发展,中国游客赴越南旅游人数呈现增长趋势。中国作为越南最大的客源国,对于越南的旅游产业有着很大的影响。为促进更多中国游客赴越南旅游,制定有效的开发策略具有十分重要的意义。本文的研究内容主要分为以下几部分:首先,分析本文的研究背景,通过对越南旅游业、中国赴越以及东盟十国的旅游现状进行详细分析,从理论与现实的角度提出本文的研究意义,借鉴学者对越南旅游业的研究基础,构建本文的研究内容与思路。其次,通过分析中国赴越南的旅游现状,全面分析越南旅游业自身所处的资源及价值。针对中国赴越旅游市场进行STP分析,将中国游客市场细分为三部分:边境旅游、内地旅游、商务旅游。其中,内地旅游细分市场具有很大的潜力;然后,从经济、文化以及社会的角度分析了中国游客赴越南旅游的优势与劣势,并基于SWOT分析法对越南入境旅游市场进行详细分析。选取东盟具有旅游竞争力的三个国家,分析其对中国市场开发策略的成功之处,借鉴、应用于越南旅游业针对中国市场开发对策建议制定中。最后,对中国游客赴越旅游进行实证分析。本部分分别从中国与越南两个地方选取调查对象,并将对象分为三类:正在越南旅游的中国游客、已经赴越旅游过的中国游客、未到过越南旅游的中国游客。通过分析有旅游意愿但未到越南旅游的人群对越南旅游市场的认知、与去越南旅游过的中国游客对市场的认知,分析越南旅游业存在的优势与不足之处,然后向越南旅游业提出相关整改意见与开发策略,以促进越南旅游业发展。

关键词：越南旅游业市场开发中国游客

Antidiabetic and antioxidant activities of red seaweed Laurencia dendroidea

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Asian Pacific Journal of Tropical Biomedicine 2019年第12期9卷 501-509页

作者： The Han Nguyen Thi Huyen Nguyen Van Minh Nguyen Thi Lan phuong Nguyen Thi Van Anh tran Anh Duy Do Sang Moo Kim Faculty of Food Technology Nha Trang University02 Nguyen Dinh Chieu StreetNha Trang CityKhanh HoaVietnam Quality Control Department Institute of Vaccines and Medical BiologicalsNha Trang CityKhanh HoaVietnam Faculty of Pharmacy University of Medicine and Pharmacy of Ho Chi Minh City41 Dinh Tien Hoang StreetHo Chi Minh CityVietnam Research Department of Marine Conservation Research Institute for Marine Fisheries224 Le Lai StreetHai Phong CityVietnam Department of Marine Food Science and Technology Gangneung-Wonju National University7 Jukheon-gilGangneung 25457Republic of Korea

Objective:To investigate antidiabetic and antioxidant activities of the extract and fractions from Vietnamese red seaweed Laurencia ***:The seaweed Laurencia dendroidea was extracted by using microwave-assisted extraction method in 80%*** seaweed extract was then fractionated using different solvents(n-hexane,chloroform,ethyl acetate,butanol and water).These obtained fractions were evaluated forα-glucosidase inhibitory and antioxidant *** activities were tested using DPPH,nitric oxide radical scavenging and metal chelating *** enzyme inhibition mode was determined using Lineweaver-Burk *** acidic and thermal stabilities,the ethyl acetate fraction was treated at pH 2.0 and 100℃,*** residual inhibitory activity of the fraction was calculated based on the initial inhibitory *** in vivo antidiabetic activity,mice were divided into four groups,including normal control,diabetic control,diabetic mice treated with ethyl acetate fraction and diabetic mice treated with *** glucose level of treated mice during acute and prolonged treatments was *** evaluate the toxicity of the ethyl acetate fraction,the body weight changes and activities of liver function enzymes(aspartate transaminase,alanine transaminase and gammaglutamyl transferase)were carried ***:The extract of Laurencia dendroidea showed strongα-glucosidase inhibitory and DPPH radical scavenging *** concentrations affected bothα-glucosidase inhibitory and antioxidant activities.A 80%aqueous methanol was the suitable solvent for extraction of enzyme inhibitors and *** solvent fractions,ethyl acetate fraction had the highest inhibitory activities againstα-glucosidase with a mixed type of inhibition and the strongest antioxidant activities,and was stable under acidic and thermal *** ethyl acetate fraction treated diabetic mice significantly reduced blood glucose level compare

关键词： α-Glucosidase inhibitor Antidiabetic Antioxidant Red seaweeds Vietnam

Xanthine oxidase inhibitors from Archidendron clypearia(Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants

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Asian Pacific Journal of Tropical Medicine 2017年第6期10卷 619-626页

作者： Nguyen Thuy Duong Pham Duc Vinh phuong Thien Thuong Nguyen Thi Hoai Le Nguyen Thanh tran The Bach Nguyen Hai Nam Nguyen Hoang Anh Department of Pharmacology Hanoi University of Pharmacy Department of Pharmaceutical Analysis and Standardization National Institute of Medicinal Materials Department of Pharmacognosy Hue University of Medicine and Pharmacy Institute of Marine Biochemistry Vietnam Academy of Science and Technology Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology Department of Medicinal Chemistry Hanoi University of Pharmacy

Objective: To screen Vietnamese medicinal plants for xanthine oxidase(XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant. Methods: The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. Results: Three hundreds and eleven methanol extracts(CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/m L with inhibition rates of over 50%. The extracts of Archidendron clypearia, Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC_(50) values below 30 μg/m L. Chemical study performed on the extract of Archidendron clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and(-)-7-O-galloyltricetiflavan. The compound(-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC_(50) value of 25.5 μmol/L. Conclusions: From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC_(50) values of the methanol extracts below 30 μg/m L. Compound(-)-7-O-galloyltricetiflavan was identified as an XO inhibitor from Archidendron clypearia with IC_(50) value of 25.5 μmol/L.

关键词： Xanthine oxidase Inhibitor Medicinal plants Vietnam