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Compensation of Zn substitution and secondary phase controls effective mass and weighted mobility in In and Ga co-doped ZnO material

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Journal of Materiomics 2021年第4期7卷 742-755页

作者： Oanh Kieu Truong Le Anh Tuan Thanh Pham Ngoc Kim Pham Trang Huyen Cao Pham Truong Huu nguyen Dung Van Hoang hanh Kieu thi Ta Dai Cao Truong Hoa thi Lai Thuy Dieu thi Ung Vinh Cao Tran Thang Bach Phan aboratory of Advanced Materials University of ScienceHoChiMinh City700000Viet Nam Vietnam National University HoChiMinh City700000Viet Nam Faculty of Physics and Engineering Physics University of ScienceHoChiMinh City700000Viet Nam Faculty of Materials Science and Technology University of ScienceHoChiMinh City700000Viet Nam Center for Innovative Materials and Architectures(INOMAR) HoChiMinh CityViet Nam Institute of Materials Science Vietnam Academy of Science and TechnologyHanoi100000Viet Nam

Conductivity s and thermal conductivity k are directly related to carrier concentration while Seebeck coefficient S is inversely proportional to carrier ***,improving thermoelectric(TE)performance is ***,the first-time analysis of secondary phase-controlled TE performance in terms of density-of-state effective mass m*d,weighted mobility mw and quality factor B is discussed in ZnO *** results show that the secondary spinel phase Ga2O_(3)(ZnO)9 not only impacts on k but also on s and S at high temperature,while the effect of carrier concentration seem to be dominant at low *** the high-spinel-segregation sample,a compensation of dopant atoms from the spinel to substitutional sites in the ZnO matrix at high temperature leads to a low decreased rate of temperaturedependent m**** compensation process also induces a band sharpening,a small mw reduction,and a large B *** a result,In and Ga co-doped ZnO bulk with the highest spinel segregation achieves the greatest PF improvement by 112.8%,owing to enhanced Seebeck coefficient by 110%as compared to the good Zn-substitution sample.

关键词： Thermoelectrics In and Ga co-Doped ZnO Secondary phase Zn substitution DOS effective Mass Weighted mobility

Understanding bike trip patterns leveraging bike sharing system open data

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Frontiers of Computer Science 2017年第1期11卷 38-48页

作者： Longbiao CHEN Xiaojuan MA thi-Mai-Trang nguyen Gang PAN Jeremie JAKUBOWICZ Institut Mines-Telecom Telecom SudParis UMR CNRS Samovar Evry 91000 France Laboratoire d'Informatique de Paris 6 (LIP6) University of Paris 6 Paris 75005 France College of Computer Science Zhejiang University Hangzhou 310027 China Department of Computer Science and Engineering Hong Kong University of Science and Technology Hong Kong China

Bike sharing systems are booming globally as a green and flexible transportation mode, but the flexibility also brings difficulties in keeping the bike stations balanced with enough bikes and docks. Understanding the spatio-temporal bike trip patterns in a bike sharing system, such as the popular trip origins and destinations during rush hours, is important for researchers to design models for bike scheduling and sta- tion management. However, due to privacy and operational concerns, bike trip data are usually not publicly available in many cities. Instead, the station feeds about real-time bike and dock number in stations are usually public, which we refer to as bike sharing system open data. In this paper, we propose an approach to infer the spatio-temporal bike trip patterns from the public station feeds. Since the number of possible trips （i.e., origin-destination station pairs） is much larger than the number of stations, we define the trip infer- ence as an ill-posed inverse problem. To solve this problem, we identify the sparsity and locality properties of bike trip patterns, and propose a sparse and weighted regularization model to impose both properties in the solution. We evaluate our method using real-world data from Washington, D.C. and New York City. Results show that our method can effectively infer the spatio-temporal bike trip patterns and outperform the baselines in both cities.

关键词： bike sharing system open data ill-posed inverse problems urban computing

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中国企业在越南跨国经营战略研究

中国企业在越南跨国经营战略研究

作者： nguyen thi hanh（阮氏幸）西北农林科技大学

学位级别：硕士

经济全球化是当今世界经济的趋势,也是我们最值得关注的外部环境。在经济全球化趋势、中国加入世界贸易组织(WTO)新形势下以及中国——东盟自由贸易区的建立使中国企业有了更多的进入国际市场的机会,因此,越来越多中国企业走出国门进入... 详细信息

经济全球化是当今世界经济的趋势,也是我们最值得关注的外部环境。在经济全球化趋势、中国加入世界贸易组织(WTO)新形势下以及中国——东盟自由贸易区的建立使中国企业有了更多的进入国际市场的机会,因此,越来越多中国企业走出国门进入了国际市场,开始了国际化经营。中国企业国际化初期选择“由近而远”的区位选择,而越南是中国重要邻邦,也是东南亚地区的重要国家,步入经济快速发展阶段,越南的快速发展引起了外部世界的广泛关注,自然成为中国企业跨国经营的理想国家。越南作为一个发展中国家,以其优越的地理位置、强劲的发展势头、低廉的劳动力成本、日趋完备的政策以及不断优化的投资环境成为中国企业实现“走出去”战略所瞄准的潜力市场。本研究共分为五章。第一章导论主要阐述了论文研究的背景、意义,回顾了国内外文献综述,并对文章思路、方法以及创新之处做了说明。第二章介绍了跨国经营战略相关理论:经济全球化理论、直接投资理论、企业跨国经营理论、垄断优势理论、市场内部化理论、国际生产折衷理论、边际产业扩张理论、企业跨国文化管理。第三章介绍外国企业在越南跨国经营总体情况及中国企业在越南跨国经营现状,从而指出中国企业在越南展开跨国经营过程中所取得的成果及存在的问题。第四章运用SWOT方法分析了中国企业在越南跨国经营的优势、劣势、机会、威胁四个方面。第五章研究中国企业在越南跨国经营战略选择及对策建议。研究结果显示,中国投资越南的主要形式有:对越直接投资、工程承包与劳务合作、双边贸易。中国企业对越南投资开始于1988年,截止2014年底,中国对越南投资的项目总数为1082个、注册投资总额为79.4亿美元。目前,中国在越南全国63个省市中的55个进行投资,主要集中于胡志明市、河内、海防和广宁等。中国企业在越南所选择的跨国经营战略主要有市场进入战略、创新战略、营本土化战略、价格战略、推进品牌战略。

关键词：中国企业越南跨国经营战略

Studying on Tyrosinase Inhibition Activity of Some Vietnamese Folk Plants Aims to Use in Skin-Whitening Cosmetics

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American Journal of Plant Sciences 2017年第6期8卷 1319-1328页

作者： nguyen thi My hanh nguyen Kim Phi Phung Quach Ngo Diem Phuong Department of Plant Biotech and Biotransformation Faculty of Biology-Biotechnology University of Science Vietnam National University-Ho Chi Minh City Ho Chi Minh City Vietnam Department of Organic Chemistry Faculty of Chemistry University of Science Vietnam National University-Ho Chi Minh City Ho Chi Minh City Vietnam

White mulberry Morus alba and jackfruit Artocarpus heterophyllus are two of seven chosen Vietnamese folk plants which showed the highest tyrosinase inhibition activity. Besides, both of them showed antioxidant and antibacterial activities. Especially, the Sulforhodamine B (SRB) assay test result of the root core extract of M. alba figured out its non-toxicity on foreskin fibroblasts.

关键词： Morus alba Tyrosinase Inhibition Activity Antibacterial Antioxidant

Shear strength model of the reinforced concrete beams with embedded through-section strengthening bars

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Frontiers of Structural and Civil Engineering 2022年第7期16卷 843-857页

作者： Linh Van hong BUI Phuoc Trong nguyen Faculty of Civil Engineering Ho Chi Minh City Open UniversityHo Chi Minh City 700000Vietnam

In this study,finite element(FE)analysis is utilized to investigate the shear capacity of reinforced concrete(RC)beams strengthened with embedded through-section(ETS)*** of critical variables on the beam shear strength,including the compressive strength of concrete,stiffness ratio between ETS bars and steel stirrups,and use of ETS strengthening system alone,are parametrically investigated.A promising method based on the bond mechanism between ETS strengthening and concrete is then proposed for predicting the shear resistance forces of the strengthened *** expression for the maximum bond stress of the ETS bars to concrete is *** new expression eliminates the difficulty in the search and selection of appropriate bond parameters from adhesion *** results obtained from the FE models and analytical models are validated by comparison with those measured from the ***,the model proposed in this study demonstrates better performance and more accuracy for prediction of the beam shear-carrying capacity than those of existing *** results obtained from this study can also serve researchers and engineers in selection of the proper shear strength models for design of ETS-strengthened RC beams.

关键词： embedded through-section strengthening fiber-reinforced polymer finite element shear strength model bond mechanism

Promote Combinational Researches, Training, and Applied Scientific Technology in Universities and Institutes in Vietnam

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Sociology Study 2016年第5期6卷 342-347页

作者： thi Dung nguyen hong Phuc nguyen University of Labour and Social Affairs Hanoi city Viemam Military Medical Chamber National Defense AcademyHanoi city Vietnam

To promote the combination of research, training, and scientific technology application is the main policy of the Vietnam Communist Party and State of their management to their meeting of the needs toward their radical and comprehensive renovation with educational and training processes. There are some solutions such as： To develop a national project on combination of research and scientific technology application in social science in Vietnam was administered, to develop a set of criteria to ensure effectiveness of combination of research and training which will be based on the needs of society was assessed, to increase self-control of research institutes and universities of social science sector in combination of research and scientific technology application was examined, to be continued of the renovation management mechanism was managed, the cost norm and means of providing finance research and scientific technology application in social science were founded. The comprehensive legal framework and criteria of combination of research and scientific technology application as a basic for evaluating activities of research and scientific technology application in social science were used. Suggestions that this study was to apply scientific technology in transferring national university and investigation of the key universities into universities＇ researches were provided.

关键词： Scientific train institute university social science

Unpredictable Placental Abruption: Case Series

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Case Reports in Clinical Medicine 2020年第6期9卷 165-175页

作者： nguyen hong Hoa nguyen thi Mong Tuyen Department of Obstetrics & Gynecology Faculty of Medicine University of Medicine and Pharmacy at Ho Chi Minh City Ho Chi Minh City Vietnam Department of Obstetrics Tu Du Hospital Ho Chi Minh City Vietnam

Background: The diagnosis of placental abruption is primarily clinical, but findings from imaging, laboratory, and postpartum pathologic studies can be used to support the clinical diagnosis. In patients with classic symptoms, fetal heart rate abnormalities, intrauterine fetal demise, and/or disseminated intravascular coagulation strongly support the clinical diagnosis and indicate extensive placental separation. In a few cases, placental separation has not been recognized and was only identified upon cesarean section as an incidental finding. Objectives: To describe the clinical presentations and pregnancy outcomes of placental abruption cases that are not diagnosed before cesarean delivery, termed “unpredictable placental abruption” and also cases diagnosed before cesarean delivery, termed “predictable placental abruption”. Methods: A retrospective analysis of 100 cases of placental abruption was identified by cesarean delivery at Tu Du hospital from September 2018 to May 2019. Clinical variables were compared between the unpredictable and predictable groups. The unpredictable group consists of cases that are not diagnosed before cesarean delivery, while the predictable cases were identified placental separation before cesarean delivery. The maternal and fetal outcomes were also studied. Results: In 100 cases of placental, abruption by gross clinical examination of the placenta at the time operation revealed that, 33% were unpredictable. Placental abruption attributed to maternal complications included one case of total hysterectomy (1%) with no cases of disseminated intravascular coagulation (DIC), shock or maternal death;specifically, this case of total hysterectomy appeared with predictable one. There were two cases of stillbirths. Among the 98 live neonates, 15 cases (14.7%) experienced severe birth asphyxia resulting in eight neonatal deaths;two of which were caused by heart disease and necrotizing enterocolitis. Sixty-thre

关键词： Placental Abruption Pregnancy Outcomes Concealed Placental Abruption Chronic Placental Abruption

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改善越南旅游行业的人力资源结构和素质

改善越南旅游行业的人力资源结构和素质

作者： nguyen hong hanh 宁波大学

学位级别：硕士

旅游是目前全球最大的产业和发展最快的新兴产业之一。对于世界个个国家乃至越南，旅游是重要的服务经济行业。越南具有丰富的旅游资源，因此旅游在成为越南的重点经济行业。旅游业是国家财政收入的主要资源并为了社会创造了大量的就业... 详细信息

旅游是目前全球最大的产业和发展最快的新兴产业之一。对于世界个个国家乃至越南，旅游是重要的服务经济行业。越南具有丰富的旅游资源，因此旅游在成为越南的重点经济行业。旅游业是国家财政收入的主要资源并为了社会创造了大量的就业机会。人力资源在生产过程中的重要投入力量。对于旅游行业，人力因素起了更大的作用，它决定本行业的质量以便吸引更多的游客。人力资源的能力和质量会决定开发以及保护国家的旅游资源潜力的效果。旅游行业包括很多经营形式以及不同的特点，但是主要形式是旅游公司，它在该行业起的重要作用。因此本论文集中研究越南旅游行业的直接劳动队伍。近期，旅游行业的人力资源还存在很多限制，数量缺少，质量不好，机构不平衡。因此为了更加发挥自然的便利条件，越南应该策划具有现代化趋向的发展战略。本论文主要研究越南旅游行业的人力资源。本论文的作者调查越南旅游行业和旅游公司的人力资源发展情况。本论文分析并评价越南旅游企业的职员数量，质量和结构以及国家的有关该行业的人力发展政策。从此，本论文提出一些关于越南旅游公司在世界化经济过程中的人力资源发展的观点和建议。为了能够符合国家政府的发展政策，本论文提出一些解决办法，如加强国家对人力资源开发的管理，完善培训中心以及旅游公司的人力资源培训。作者相信在国家和个企业的关照和投资下，越南人力资源会不断地改善并发展，越南的旅游行业会长期，持续和健康地发展。

关键词：人力资源结构人力资源素质旅游业越南

Quadruple[6]Helicene Featuring Pyrene Core:Unraveling Contorted Aromatic Core with Larger Effective Conjugation

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Precision Chemistry 2024年第9期2卷 488-494页

作者： Christopher Wallerius Otgonbayar Erdene-Ochir Eva Van Doeselar Ronald Alle Anh Tu nguyen Marvin F.Schumacher Arne Lützen Klaus Meerholz Sai Ho Pun Department of Chemistry University of CologneCologne 50939Germany Kekulé-Institute of Organic Chemistry and Biochemistry University of BonnBonn 53121Germany Department of Chemistry Hong Kong University of Science and TechnologyClean Water BayHong KongChina

Multiple helicenes display distinct aromatic cores characterized by highly twisted rings that are shared or fused with constituent helicene *** these aromatic cores unlocks avenues for creating multiple helicenes with distinct properties and *** we report the synthesis of a quadruple[6]helicene featuring pyrene as the aromatic *** synthesis involved key steps of the annulativeπ-extension reaction and Scholl *** extending multiple helicenes along the axial direction,the degree of contortion of the aromatic core can be controlled from nearly flat to highly ***,quadruple[6]-helicene exhibits a significant red-shift of 0.49 eV compared to quadruple[4]-helicenes,of which the red-shift arises from bothπ-extension and augmented effective conjugation due to enhanced *** chemical calculations demonstrate that the degree of contortion in the pyrene core adeptly governs the energy levels of the HOMO and LUMO,which offers an alternative strategy beyond mere enlargement of theπ*** intriguing serendipitous finding reveals the formation of one-molecule-thick supramolecular homochiral nanosheets through selfinterlocking interactions of enantiomers in single crystals,a rare packing motif for multiple helicenes.

关键词： Helicenes Polycyclic aromatics Pyrene Core contortion Effective conjugation