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Journal of Analytical Sciences, Methods and Instrumentation 2019年第2期9卷 22-29页

作者： dang Hong Ngoc Quy Pham Ngoc Tuan nguyen Nhi Dien Nuclear Research Institute DaLat Viet Nam

The outstanding advantage of digital signal processing (DSP) techniques and Field Programmable Gate Array (FPGA) technology is capable of improving the quality of the experimental measurements for nuclear radiation. In this article, a compact DMCA 8 K was designed and manufactured using DSP technique based on FPGA technology. In particular, the output of the preamplifier is completely processed by digital techniques which are obtained from the analog-to-digital converter (ADC) to calculate the baseline, DC offset, energy peaks, pile up, threshold discrimination and then the form of energy spectrum. The Spartan-6 board is used as a hardware for the development of the digital multichannel analyzer (DMCA), which is equipped with the 14-bit AD6645 with 62.5 Msps sample rate. The application software for instrument control, data acquisition and data processing was written under C++ builder via the RS-232 interface. The designed DMCA system has been tested with a HPGe detector using gamma sources of 60Co and 137Cs and a reference pulser.

关键词： Field Programmable Gate Arrays Digital Multichannel Analyzer Integral Nonlinearity Digital Signal Processing

Soil Gas Radon Measurement for Identifying Active Faults in Thua Thien Hue (Vietnam)

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Journal of Geoscience and Environment Protection 2020年第7期8卷 44-64页

作者： Pham Tich Xuan nguyen Anh Duong Vu Van Chinh Pham Thanh dang nguyen Xuan Qua nguyen Van Pho Institute of Geological Sciences Vietnam Academy of Science and Technology Hanoi Vietnam Institute of Geophysics Vietnam Academy of Science and Technology Hanoi Vietnam

The solid-state nuclear track detectors have long been applied to assess the activity of tectonic faults. We measured the Radon (Rn) concentration in soil gas on 09 profiles with a total of 245 measurement points in Thua Thien Hue area (Vietnam). Measurement results show that the Rn concentration in soil gas ranges from ~10 Bq/m3 to 144,570 Bq/m3. There is a clear difference in the Rn concentration on the granite rock of Dai Loc complex compared to the remaining rocks. The calculated background value and anomaly threshold of Rn concentration on the granite rock of Dai Loc complex and on the remaining rocks are 33,488 Bq/m3, 82,839 Bq/m3 and 5313 Bq/m3, 24,850 Bq/m3 respectively. Spatial distribution of Rn concentration in soil gas reflects the existence of faults since Rn concentration increases at the points above or near fault lines. The level of expression of fault activity is assessed by radon activity index (KRn), which is calculated by the ratio of anomaly value to background value of Rn concentration. According to KRn, in Thua Thien Hue area, only the Dakrong-Hue fault shows a strong expression of activity with high and very high KRn (the maximum KRn = 27.21). The Truong Son, Huu Trach River, Ta Trach River and Bo River fault zones do not show clear activity with low and medium KRn. There is no Rn anomaly value recorded on the Rao Trang fault, demonstrating that it is likely to be inactive at present. The study results indicate that the Rn concentration in soil gas is a strong evidence of the existence of faults or tectonic fracture zones as the Rn concentration always increases at the points above or near the fault line.

关键词： Radon Active Fault Radon Activity Index Thua Thien Hue Vietnam

Vulnerability to Flood in the Vietnamese Mekong Delta： Mapping and Uncertainty Assessment

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Journal of Environmental Science and Engineering(B) 2013年第4期2卷 229-237页

作者： Van Pham dang Tri nguyen Hieu Trung Vo Quoc Thanh College of Environment and Natural Resources Can Tho University Can Tho City Vietnam

The Vietnamese Mekong Delta is located at the end of the Mekong River, one of the 10 largest rivers in the world. It plays an important role, especially in terms of food security for not only Vietnam but also the world. However, the Vietnamese Mekong Delta is projected to be heavily affected by：（1） the annual （fluvial） flood, which would be changed in terms of time and spatial distribution after impacts of climate change scenarios （i.e., sharper hydrograph with shorter flood period）; and （2） sea level rise. Such combination would result in significant changes of surface water resources, leading to consequent impacts on the existing fanning systems in the Vietnamese Mekong Delta. Therefore, this paper presents a new approach of integrating a one-dimensional hydrodynamic model （ISIS-1 D） with GIS （Geographic Information System ） analyses to：（1） identify priority areas for flood adaptation and mitigation; （2） provide an insight to local decision-makers in the Vietnamese Mekong Delta in changes of future floods.

关键词： Vulnerability uncertainty flood Vietnamese Mekong delta.

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越南广义省基础教育财政管理研究

越南广义省基础教育财政管理研究

作者： nguyen dang THUY THUY（阮登翠翠）华中师范大学

学位级别：硕士

进入21世纪后,教育愈加成为经济社会发展的源动力。越南政府、社会非常重视教育事业的发展,教育规模与教育投入增长迅速,极大地促进了越南教育事业的扩张。但是,受限于越南整体的经济社会发展水平,其教育投入经费始终相对有限,而教育规... 详细信息

进入21世纪后,教育愈加成为经济社会发展的源动力。越南政府、社会非常重视教育事业的发展,教育规模与教育投入增长迅速,极大地促进了越南教育事业的扩张。但是,受限于越南整体的经济社会发展水平,其教育投入经费始终相对有限,而教育规模始终持续扩张,对学校教育财政管理,提高财政投入的利用效率的提出了更高的要求。因此,本文以越南广义省为例,研究其基础教育财政管理工作的现状,分析财政管理工作存在的问题,并提出针对性的改善措施。广义省是越南中部地区的重点省市,但是其城镇化进程慢,80%以上的人口分布于农村,在一定程度上限制了广义省经济社会的发展。研究发现,广义省的教育财政管理存在一定的问题,主要表现为教育财政投入相对不足,用于个人支出的比例过高,教育财政更多的是表现为生存型财政,而发展相对乏力。对公立教育而言,公立教育的基础设施支出增长乏力,教育培训支出占比较少,学费收入逐年增加,对贫困生的负担日益增加;对外公立教育而言,外公立教育以学费收入为主,主要用于支付教师工资、租地费用以及日常运行经费,可用于教师培训的费用以及利润额度较低，限制了外公立学校教师的发展以及投资者投资的积极性。上述问题制约了广义省基础教育事业的发展,对此,笔者认为应当从以下几方面采取措施:加大越南政府对基础教育的投入、建立与完善专项财政转移支付制度、积极拓宽教育经费筹措渠道、完善越南广义省基础教育财政管理制度。本文主要由五大部分构成:第一的部分是分为研究背景及意义,介绍了研究背景,研究目的与意义,研究问题与方法,概念界定等;第二部分是从文献综述,分越南国内外视角梳理基础教育财政管理的相关文献,奠定文献资料基础;第三部分为越南广义省基础教育事业发展概况,从公立学校、外公立学校、师资、教室、教育质量等方面介绍了广义省基础教育事业的状况;第四部分为广义省基础教育财政管理概况,介绍了广义省基础教育财政管理的内容,从此分析了广义省基础教育财政管理的现状,指出其存在的问题;第五部分,针对广义省基础教育财政管理中存在的问题,提出相应的对策建议,以期能够改善广义省教育财政管理。

关键词：广义省基础教育教育财政管理

Optimum Determination of Partial Transmission Ratios of Mechanical Driven Systems Using a V-belt and a Three-Step Helical Gearbox

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Journal of Environmental Science and Engineering(B) 2017年第6期6卷 328-331页

作者： dang Anh Tuan nguyen Khac Tuan Vu Ngoc Pi Mechanical Engineering Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam Automotive and Power Machinery Faculty Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam

This paper introduces a new study on the optimum calculation of partial transmission ratios of a mechanical drive system using a V-belt and a three-step helical gearbox in order to get the minimum size of the system. The chosen objective function was the cross section dimension of the system. In solving the optimization problem, the design equation for pitting resistance of a gear set was investigated and equations on moment equilibrium condition of a mechanic system including a V-belt and three helical gear units and their regular resistance condition were analysed. From the results of the study, effective formulas for determination of the partial ratios of the V-belt and three-step helical gearboxes were introduced. As using explicit models, the partial ratios can be determined accurately and simply.

关键词： Transmission ratio gearbox design optimum design V-belt drive helical gearbox.

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

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

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

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