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Structural, Optical and Photocatalytic Properties of Cu²⁺ Doped ZnO Nanorods with Using HMTA Solvent Prepared by Hydrothermal Method

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Journal of Materials Science and Chemical Engineering 2023年第7期11卷 20-30页

作者： nguyen Thi Tuyet Mai nguyen Thi Lan Trinh Xuan Anh Ta Ngoc Dung Huynh dang Chinh School of Chemical Engineering Hanoi University of Science and Technology Hanoi Vietnam

In this experiment, Cu2+ doped ZnO (Cu-ZnO) nanorods materials have been fabricated by hydrothermal method. Cu2+ ions were doped into ZnO with ratios of 2, 5 and 7 mol.% (compared to the mole’s number of Zn2+). The hexamethylenetetramine (HMTA) solvent used for the fabrication of Cu-ZnO nanorods with the mole ratio of Zn2+:HMTA = 1:4. The characteristics of the materials were analyzed by techniques, such as XRD, Raman shift, SEM and UV-vis diffuse reflectance spectra (DRS). The photocatalytic properties of the materials were investigated by the decomposition of the methylene blue (MB) dye solution under ultraviolet light. The results show that the size of Cu-ZnO nanorods was reduced when the Cu2+ doping ratio increased from 2 mol.% to 7 mol.%. The decomposition efficiency of the MB dye solution reached 92% - 97%, corresponding to the Cu2+ doping ratio changed from 2 - 7 mol.% (after 40 minutes of ultraviolet irradiation). The highest efficiency for the decomposition of the MB solution was obtained at a Cu2+ doping ratio of 2 mol.%.

关键词： Cu2+ Doped ZnO Nanorods ZnO Nanomaterials Hexamethylenetetramine (HMTA) Photocatalytics Methylene Blue Hydrothermal Method UV Irradiation

Structure, Plastic Deformation of Polyethylene: A Molecular Dynamics Method

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Advances in Materials Physics and Chemistry 2020年第6期10卷 125-150页

作者： Dung nguyen Trong Tuan Tran Quoc Hue dang Thi Minh Cuong nguyen Chinh Van Duong Quoc Faculty of Physics Hanoi National University of Education Ha Noi Vietnam Faculty of Basic Science University of Transport Technology Ha Noi Vietnam Faculty of Electrical and Electronics Engineering Thuyloi University Ha Noi Vietnam

This paper studies the influence factors of atoms number (N) at temperature (T) and after annealing time (t) on the structure shape and the plastic deformation of Polyethylene C2H4 (PE) by the Molecular Dynamics (MD) method with Dreading pair interaction, cyclic boundary conditions and plastic deformation of Polyethylene (PE) be done by stretching method according to the z-axis. The results of structure, plastic deformation of PE are analyzed through size (l), the total energy of the system (Etot), shape and associated energy (Ebond), angular binding energy (Eangle), energy Edihedral, interactive energy Vander Walls (Enon-bonding). When increasing N, t leads to the number of structural units of Face-Centred Cubic (FCC), Body-Centered Cubic (BCC) and Hexagonal Close-Packed (HCP) increasing, but Amorphous (Amor) decreases while the angle between the atoms is a constant corresponding to 109.5°. Besides, the length of the link (r) increases from r = 1.529 Å to r = 1.558 Å while the plastic deformation energy of PE gets an enormous change and the bonding angle at 109.27°. The length of the link r = 1.529 Å and the size (l) of the PE material increase from l = 3.7

关键词： Molecular Dynamics Atoms Number Annealing Time Polyethylene Plastic Deformation

Novel Mn-doped Ge： From Basis to Application

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材料科学与工程（中英文A版） 2012年第2期2卷 248-271页

作者： dang Duc Dung nguyen Thi Mua Hoang Vu Chung Sunglae Cho Department of Physics University of Ulsan Ulsan 680-749 Republic of Korea Department of General Physics School of Engineering Physics Ha Noi University of Science and Technology 1 Dai Co Viet roadHa Noi Viet Nam Hanoi Univerisity of Frevention and Fight Fire Vietnam WPI Center for Material Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan

Spintronic materials were promised to application to real devices, especially in half-metallic materials. Ge-based magnetic semiconductors have attracted a great deal of attention cause of compatibility with the current Si-based processing technology. Around 10 years from discovery of the magnetic semiconductor Mn-doped Ge, a lot of studies have been paid to give insight into these systems. In this work, we first review the current efforts on the experimental observation of the ferromagnetism of Mn-doped Ge and also some theoretical predictions such as the band structure, magnetic properties etc. The methods to grow Mn-doped Ge from three-dimension to zero-dimension were described and some parameters of the growth which will be also considered. Besides that, the clusters and theirs properties will be summarized. Finally, the co-doping effect of Mn-doped Ge and some applications will be discussed in details.

关键词： Mn掺杂应用磁性半导体基础自旋电子材料半金属材料加工技术能带结构

A Design Configuration of an FPGA-Based Coincident Spectrometry System

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Journal of Analytical Sciences, Methods and Instrumentation 2013年第3期3卷 158-162页

作者： Pham Dinh Khang nguyen Nhi Dien dang Lanh nguyen Xuan Hai Pham Ngoc Tuan nguyen Duc Hoa nguyen An Son Nuclear Research Institute Dalat Vietnam Nuclear Training Center Hanoi Vietnam University of Dalat Dalat Vietnam University of Dalat Dalat Vietnam.

In the past, most of popular coincidence spectrometers were normally based on traditional electronics techniques such as time to amplitude conversion or logic selecting coincidence unit. They were complicated and it is not convenient for us to use them. This paper deals with a new design of a contemporary coincidence spectrometer which is based on Field Programmable Gate Arrays (FPGA) devices via Digital Signal Processing (DSP) techniques with Hardware Description Language (VHDL). The outstanding advantage of DSP techniques and FPGA technology is capable of enhancement of the quality of the experimental measurements for nuclear radiation. The designed configuration of the traditional system was tested on the PCI 7811R board of National Instruments while the digital systems were establishing with FPGA devices. The purpose of this work is referring to the principle for construction of an FPGA-based system capable of replacing a conventional system. Therefore, a novel approach for in-house development of digital techniques is presented. The method for designing the system is utilization of slow-fast coincidence configurations with two HPGe detectors obtaining a pair of coincidence events, processing data in DSP algorithms. The significant and noticeable results are the operating frequency of 80 MHz and system timestamp window of approximately 10 ns.

关键词： Digital Signal Processing FPGA VHDL

Preparation and Characterization of Reduced Graphene-P3HT Composite Thin Films for Use as Transparent Conducting Electrodes

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Materials Sciences and Applications 2018年第5期9卷 464-472页

作者： Lam Minh Long dang Dinh Long nguyen Phuong Hoai Nam nguyen Trong Tinh Sergei Antonovic Chizhik nguyen Nang Dinh University of Engineering and Technology VNU in Hanoi Hanoi Vietnam Institute of Applied Physics and Scientific Instrument Vietnamese Academy of Science and Technology Hanoi Vietnam A.V. Luikov Heat and Mass Transfer Institute National Academy of Sciences of Belarus Minsk Belarus

With the aim of producing simple and effective transparent conducting electrodes, the conducting polymer poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide film (rGO) (called rGO-P3HT) was prepared by spin-coating method. Structural, electrical and optical characterization showed that rGO-P3HT films 9.0 wt% P3HT exhibited good stability when exposed to the ambient atmosphere. These composite films of 200 nm thickness possess a sheet resistance and transparency of R□~ 17Ω and T ~ 72%, respectively. Owing to containing conducting polymer, rGO-P3HT-coated glass could be efficiently used in photovoltaic applications, in organic solar cells in particular, with the replacement of the indium tin oxide (ITO) and fluorine tin oxide (FTO) electrodes.

关键词： Composite rGO-P3HT Thin Films Transparent Conducting Electrode Sheet Resistance Transmittance

It Takes Two to Tango： Entrepreneurship and Creativity in Troubled Times--Vietnam 2012

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Sociology Study 2012年第9期2卷 662-674页

作者： Nancy K. Napier dang Le nguyen Vu Quan Hoang Vuong Boise State University USA/Aalborg University Denmark Trung nguyen Coffee Group Vietnam Universite Libre de Bruxelles Belgium

This study focuses on perceived values of entrepreneurship and creativity within a turbulent environment. The initial hypothesis is that a typical entrepreneurial process carries with its ＂creativity-enabling elements＂. In a normal situation, businesses focus on optimizing their resources for commercial gains, thus perceptions about values of entrepreneurial creativity are usually vague. However, in difficult times, the difference between survival and failure may be creativity. This paper examines many previous findings on entrepreneurship and creativity, and suggests a highly possible ＂organic growth＂ of creativity in an entrepreneurial environment and reinforcing value of entrepreneurship when creativity power is present. In other words, the authors see each idea reinforcing the other. The authors survey Vietnamese firms during the chaotic year of 2012 to learn about the ＂entrepreneurship-creativity nexus＂, looking at influential cultural values, namely risk tolerance, relationship, and dependence on resources--to assess how they influence entrepreneurial decisions. A set of 137 qualified responses was obtained for this statistical examination. A categorical data analysis is performed to confirm that creativity and entrepreneurial spirit could hardly be separate, for both entrepreneurial and accomplished companies. Although the most important factor during implementation is still ＂relationship＂, business people are increasingly aware of the need of creativity/innovation in troubled times.

关键词： Creativity entrepreneurship economic transition Vietnam

Hip Tuberculosis at Stage IV: Outcomes and Some Conditions for Total Hip Replacement

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Open Journal of Orthopedics 2022年第4期12卷 183-194页

作者： Do dang Hoan Dao Xuan Thanh nguyen Khac Trang Ngo Van Toan Department of General Surgery National Lung Hospital Hanoi Vietam Hanoi Medical University Hanoi Vietam Department of Orthopaedic Hanoi Medical University Hospital Hanoi Vietam Hanoi Medical University Hospital Hanoi Vietam

Background: Treatment of hip disorders during active hip tuberculosis has long been a controversial issue. Some authors have reported performing hip replacement with different strategies with very good outcomes. This study aimed to describe the surgical outcomes and necessary conditions for total hip replacement in active hip tuberculosis. Methods: We conducted a quasi-experimental study. The study enrolled 40 patients with 42 active tuberculosis hips at stage IV treated by total hip replacement from October 2016 to December 2019 at the National Lung Hospital. We followed up with the patients for at least 12 months, evaluated surgical outcomes, and investigated the factors associated with these outcomes by logistic regression analysis. Results: Surgical outcomes showed that 37 patients (88.1%) had excellent hip function, no abscesses, and no sinus tract formation. Four cases (9.5%) had sinus tract formations. One case (2.4%) had good hip function. Binary logistic regression models revealed that sinus tract formation was associated with preoperative tuberculosis infection syndrome. The average time to obtain antituberculosis drug treatment preoperatively was 4.6 weeks. Conclusion: Total hip replacement for active hip tuberculosis is a practical and promising treatment method. Surgeons should consider improving patients’ conditions before performing total hip replacement, administering antitubercular drugs, and arthrotomy to eliminate all abscesses, and decrease the risk of tuberculosis infection syndrome and the inflammatory response.

关键词： Active Hip Tuberculosis Stage IV Total Hip Replacement

Characterization of Electrochromic Properties of Polyaniline Thin Films Electropolymerized in H₂SO₄ Solution

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Open Journal of Organic Polymer Materials 2016年第1期6卷 30-37页

作者： dang Hai Ninh Tran Thi Thao Pham Duy Long nguyen Nang Dinh University of Engineering and Technology Vietnam National University Hanoi Hanoi Vietnam Institute of Materials Science Vietnamese Academy of Science and Technology Hanoi Vietnam

Polyaniline (PANI) onto indium-doped tin-oxide (ITO)-coated glass samples were prepared by electroopolymerization in 0.5 M H2SO4 solution. Structure and morphology characterization of the PANI films demonstrated that the films were grown onto ITO substrates in the form of polycrystalline microbelts separated by micropores. By analysing the UV-Vis absorption spectra of the PANI films, the energy bandgap was found to be approximately 2.75 eV. The PANI/ITO films exhibited a good reversible electrochromic display (ECD) performance when cycled in 0.1 M LiClO4 + pro-pylene carbonate. The response time of the ECD coloration was found to be as small as 15 s and the coloration efficiency was found to be 8.85 cm2 C-1. After 100 cycles of the ECD performance, the cyclic voltammetry curve of the working electrode maintained unchanged. This demonstrates that the electropolymerized PANI films can be served as a good candidate for ECD applications, taking advantage of their excellent properties in terms of chemical stability.

关键词： Polyaniline Thin Films UV-Vis Absorption Electrochromic Property

中国B2C电子商务模式研究及对越南电商的启示

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中国B2C电子商务模式研究及对越南电商的启示

作者：阮日英（nguyen nhat Anh）华北电力大学(北京)

学位级别：硕士

随着工业化进程的加快,信息技术蓬勃发展,电子商务已经成为客户与企业之间的桥梁,客户只需要简单的操作就可以预定几乎所有的全球产品线。20世纪90年代,EDI的电子商务在中国已经非常成熟,EDI的应用使企业能够显著提高工作效率,降低交易... 详细信息

随着工业化进程的加快,信息技术蓬勃发展,电子商务已经成为客户与企业之间的桥梁,客户只需要简单的操作就可以预定几乎所有的全球产品线。20世纪90年代,EDI的电子商务在中国已经非常成熟,EDI的应用使企业能够显著提高工作效率,降低交易成本,减少交易过程中所造成的错误,加强国际贸易交易的成功率。最近几年,中国在电子商务方面发展迅猛,已成为电子商务强国。其发展历程对越南电子商务有非常重要的影响。本文首先阐明了电子商务的研究意义,以及电子商务的运行模式、物流和分配模式以及盈利模式等方面的国内外研究现状。随后详细介绍了中国B2C电子商务从工具、渠道、基础设施到经济体这四个阶段的发展历程及中国B2C电子商务的发展现状,并从实际出发,概括性地介绍了包括天猫、京东等在内的中国几大B2C电子商务企业的发展现状。同时还提出了中国电子商务存在的一系列问题,如网络基础设施问题、安全问题、人才问题等。为了更好地理解B2C模式在中国是如何发展的,本文分别针对商务运营模式、物流配送模式、盈利模式三方面进行了深入分析。主要内容包括:商务运营模式的流程和要求;三种物流配送模式的定义及主要特征,并列举了各配送模式代表性网站,分析对比了其适用性及优缺点;根据价值创造结构的不同详细分析了三种不同盈利模式,对其特点进行了多方面的对比分析。并且本文以京东商城为具体案例,对其运营过程、配送模式、盈利方式进行了详细分析。论文的最后阐明了中国B2C电子商务模式对越南电商的启示,着重分析了在越南的电子商务环境中存在的客观影响因素,如国家的经济、社会和管理机制等,主观方面也有提及。通过评估和案例分析,循着企业的成长轨迹,在它们的成败得失之间总结经验和教训,寻找规律和对策,以期能够给企业成长和行业发展提供一些指导。本文通过对越南的电子商务市场的深入研究,发现了其在发展过程中,电子商务认知、相关法律法规、运营流程、物流模式、网上支付等方面存在的问题,并针对这些问题提出了营造良好电子商务环境、健全电子商务法律体系、完善电子商务支付体系等科学合理的可行性建议,希望可以为越南电子商务市场的发展提供充足的理论依据。

关键词： B2C电子商务模式 B2C商业模式越南电子商务