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Optical properties and dynamic process in metal ions doped on CdSe quantum dots sensitized solar cells

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Chinese Optics Letters 2018年第7期16卷 71-77页

作者： Ha Thanh Tung Dang Huu phuc Institute of Research and Development Duy Tan University Theoretical Physics Research Group Advanced Institute of Materials Science Ton Duc Thang University Faculty of Applied Sciences Ton Duc Thang University

In recent years, the nanostructure for solar cells have attracted considerable attention from scientists as a result of a promising candidate for low cost devices. In this work, quantum dots sensitized solar cells with effective performance based on a co-sensitized Cd S∕Cd Se：Mn2＋（or Cu2＋） nanocrystal, which was made by successive ionic layer absorption and reaction, are discussed. The optical, physical, chemical, and photovoltaic properties of quantum dots sensitized solar cells were sensitized to Mn2＋and Cu2＋dopants. Therefore, the short current（JSC）of the quantum dot sensitized solar cells is boosted dramatically from 12.351 mA∕cm2 for pure Cd Se nanoparticles to 18.990 mA∕cm2 for Mn2＋ions and 19.915 mA∕cm2 for Cu2＋ions. Actually, metal dopant extended the band gap of pure Cd Se nanoparticles, reduced recombination, enhanced the efficiency of devices, and improved the charge transfer and collection. In addition, Mn2＋and Cu2＋dopants rose to the level of the conduction band of pure Cd Se nanoparticles, which leads to the reduction of the charge recombination, enhances the lightharvesting efficiency, and improves the charge diffusion and collection. The results also were confirmed by the obtained experimental data of photoluminescence decay and electrochemical impedance spectroscopy.

关键词： CdS Cu Mn FTO Optical properties and dynamic process in metal ions doped on CdSe quantum dots sensitized solar cells

Using Visual MODFLOW Model to Assess the Efficiency of Subsurface Barrier Wall for Groundwater Flow Regulation and Reduction of Saline Intrution

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Journal of Environmental Science and Engineering(A) 2021年第3期10卷 104-115页

作者： Nguyen Minh Khuyen Doan Van Long Nguyen Tien Bach Tang Huu Dong bui Cong Du Dang Dinh phuc Department of Water Resources Management Ministry of Natural Resources and EnvironmentHanoi 100000Vietnam Vietnam Association of Hyhrogeology Hanoi 100000Vietnam

Barrier walls effectively store water,regulate underground flows,improve exploitable reserves and prevent saltwater *** effectiveness of the underground barrier wall depends not only on the hydrogeological structure,the technical parameters of the wall but also on the layout scheme of the exploitation well *** results showed that in natural conditions,the ground water level upstream of the barrier wall rose in the presence of a barrier *** wells located downstream of high barrier walls,the water level *** amount of underground current flowing into the sea decreased,the annual average value of the whole region decreased was 316 m3/day and *** presence of a wall,both the water level and the amount of evaporation *** average increase in evaporation volume during the calculation period of ten thousand days with walls was 4.114 m3/*** in presence of a wall,the amount of water that can be exploited increases by the total amount of evaporation plus the decrease in discharge to the sea and is equal to 4,424 m3/*** the exploitation condition,if the water level in the presence of wall is kept as low as in the absence of wall,the exploitation flow will increase to about 4,400 m3/day and *** the calculated water level values when there is a wall and without a wall,we can see that if the exploitation flow in presence of a wall and in the absence of wall is the same,the water level drop at the calculated observation wells upstream of the wall will decrease from 0.21 m to 3.97 *** condition of effective exploitation of the wall depends on the mining *** exploitation scheme is reasonable,the exploitation flow of the wells does not exceed the allowable flow so as not to cause the drying of the aquifer at the location of the *** upstream area of the wall reflects quite clearly as the Total dissolved solids content in observation wells upstream of the wall at the end of the calculation time is significantly reduced c

关键词： Subsurface barrier wall store water regulate underground flows.

Predicting rock size distribution in mine blasting using various novel soft computing models based on meta-heuristics and machine learning algorithms

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Geoscience Frontiers 2021年第3期12卷 458-472页

作者： Chengyu Xie Hoang Nguyen Xuan-Nam bui Yosoon Choi Jian Zhou Thao Nguyen-Trang School of Environment and Resources Xiangtan UniversityXiangtan 411105China Institute of Research and Development Duy Tan UniversityDa Nang 550000Viet Nam Department of Surface Mining Mining FacultyHanoi University of Mining and Geology18 Pho VienDuc Thang wardBac Tu Liem districtHanoi 100000Viet Nam Center for Mining Electro-Mechanical researchHanoi University of Mining and Geology18 Pho VienDuc Thang wardBac Tu Liem districtHanoi 100000Viet Nam Department of Energy Resources Engineering Pukyong National UniversityBusan 48513Republic of Korea School of Resources and Safety Engineering Central South UniversityChangsha 410083HunanChina Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh City 700000Viet Nam Faculty of Mathematics and Statistics Ton Duc Thang UniversityHo Chi Minh City 700000Viet Nam

Blasting is well-known as an effective method for fragmenting or moving rock in open-pit *** evaluate the quality of blasting,the size of rock distribution is used as a critical criterion in blasting operations.A high percentage of oversized rocks generated by blasting operations can lead to economic and environmental ***,this study proposed four novel intelligent models to predict the size of rock distribution in mine blasting in order to optimize blasting parameters,as well as the efficiency of blasting operation in open ***,a nature-inspired algorithm(i.e.,firefly algorithm-FFA)and different machine learning algorithms(i.e.,gradient boosting machine(GBM),support vector machine(SVM),Gaussian process(GP),and artificial neural network(ANN))were combined for this aim,abbreviated as FFA-GBM,FFA-SVM,FFA-GP,and FFA-ANN,***,predicted results from the abovementioned models were compared with each other using three statistical indicators(e.g.,mean absolute error,root-mean-squared error,and correlation coefficient)and color intensity *** developing and simulating the size of rock in blasting operations,136 blasting events with their images were collected and analyzed by the Split-Desktop *** which,111 events were randomly selected for the development and optimization of the ***,the remaining 25 blasting events were applied to confirm the accuracy of the proposed ***,blast design parameters were regarded as input variables to predict the size of rock in blasting ***,the obtained results revealed that the FFA is a robust optimization algorithm for estimating rock fragmentation in bench *** the models developed in this study,FFA-GBM provided the highest accuracy in predicting the size of fragmented *** other techniques(i.e.,FFA-SVM,FFA-GP,and FFA-ANN)yielded lower computational stability and ***,the FFA-GBM model can be used as a powerful

关键词： Mine blasting Rock fragmentation Artificial intelligence Hybrid model Gradient boosting machine Meta-heuristic algorithm

Combining SnO_(2-x)and g-C_(3)N_(4)nanosheets toward S-scheme heterojunction for high selectivity into green products of NO degradation reaction under visible light

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Journal of Materiomics 2022年第1期8卷 1-8页

作者： Pham Van Viet Thanh-Dat Nguyen Dai-Phat bui Cao Minh Thi Faculty of Materials Science and Technology University of ScienceVNU-HCM227 Nguyen Van Cu StreetDistrict 5Ho Chi Minh City700000Viet Nam Vietnam National University-Ho Chi Minh City Thu Duc DistrictHo Chi Minh City700000Viet Nam Ho Chi Minh City University of Technology(HUTECH) 475A Dien Bien Phu StreetBinh Thanh DistrictHo Chi Minh City700000Viet Nam

NOx emissions cause many negative impacts on the living *** photocatalysis of semiconductors is superior for nitric oxide(NO)degradation due to their low redox *** this report,we combine SnO_(2-x)/g-C_(3)N_(4)heterojunction photocatalyst toward the high selectivity into green products under visible light *** show that SnO_(2-x)/g-C_(3)N_(4)heterojunction degraded 40.8%of NO,which is 1.6 times higher than that of g-C_(3)N_(4).In addition,the selectivity coefficient of SnO_(2-x)/g-C_(3)N_(4)is higher 3 times than both pure SnO_(2-x)and g-C_(3)N_(4).Furthermore,SnO_(2-x)/g-C_(3)N_(4)expresses a superior stability for NO photocatalytic-degradation after five *** scavenger trapping test results,and electron spin resonance(ESR)analysis also provide more understanding of the charge transfer mechanism of ***_(2-x)/g-C_(3)N_(4)heterojunction shows a high removal efficiency of NO gas,making it an up-and-coming environmental treatment candidate.

关键词： G-C_(3)N_(4) NO removal Oxygen vacancies Photocatalysis S-scheme

Utilization and Satisfaction with HIV Services at 7 Provinces in Vietnam: A Cross-Sectional Study

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World Journal of AIDS 2022年第2期12卷 65-82页

作者： Le Bao Chau Pham Thi Huyen Chang Duong Minh duc Hoang Van Minh Luu Quoc Toan bui Thi Tu Quyen Le Thi Vui bui Thi Thu Ha Hanoi University of Public Health Hanoi Vietnam

The study was carried out to determine utilization and satisfaction with essential HIV services from HIV individuals and high-risk populations in 7 socioeconomic provinces nationwide. A cross-sectional approach was applied in the study. Data were collected through face-to-face interviews using self-report questionnaires. Findings from 2380 respondents indicated a high percentage of utilization as well as a high level of satisfaction, in particular among men who have sex with men (MSM) and female sex worker (FSW) sub-group. Needle, syringe, and condom programs had lower usage and satisfaction mean scores in comparison with other services. The proportion of people who used drugs (PWID) and participated in the needle and syringe program was 53.6%. HIV counseling and testing uptake proportion of overall respondents in the last 12 months was 82.2% while the rate of antiretroviral treatment among infected PWID was 74.9%. The level of satisfaction with treatment services was found to be higher than preventive interventions (p ducational attainment, and marital status with subjects’ satisfaction with several HIV services. Preventive services, especially needle, syringe and condom programs should be prioritized to scale up the coverage and effectiveness. Innovative approaches targeting at PWID should be promoted to increase their access to prevention programs as well as HIV care when needed.

关键词： HIV Service Utilization Satisfaction

Anatomic variability of the vascularized composite osteomyocutaneous fl ap from the medial femoral condyle: an anatomical study

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Plastic and Aesthetic Research 2014年第1期1卷 85-88页

作者： Trung-Hau LêThua duc-Phu bui Dang-Nhat Pham Vu-Bao Lê Albert De Mey Willy Boeckx Department of Plastic Reconstructive and Hand SurgeryHue Central HospitalHue City 47000Thừa Thiên-HuếVietnam Departments of Surgery Hue University of Medicine and PharmacyHue City 47000Thừa Thiên-HuếVietnam Department of Surgery An Sinh HospitalHo Chi Minh City 70000Vietnam Department of Plastic Surgery Brugmann University HospitalFree University of BrusselsBrussels 1020Belgium

Aim:The anatomical study and clinical application for the vascularized corticoperiosteal fl ap from the medial femoral condyle have been performed and described *** prior studies have described the composite osteomyocutaneous fl ap from the medial femoral condyle,a detailed analysis of the vascularity of this region has not yet been fully ***:This anatomical study described the variability of the arteries from the medial femoral condyle in 40 cadaveric ***:The descending genicular artery(DGA)was found in 33 of 40 cases(82.5%).The superomedial genicular artery(SGA)was present in 10 cases(25%).All 33 cases(100%)of the DGA had articular branches to the periosteum of the medial femoral *** branches and saphenous branches of the DGA were present in 25 cases(62.5%)and 26 cases(70.3%),***:The current study demonstrates that the size and length of the vessels to the medial femoral condyle are suffi cient for a vascularized bone fl ap.A careful preoperative vascular assessment is essential prior to use of the vascularized composite osteomyocutaneous fl ap from the medial femoral condyle,because of the considerable anatomical variations in different branches of the DGA.

关键词： Descending genicular artery medial femoral condyle osteomyocutaneousﬂap superomedial genicular artery

Treatment 2.0 Pilot in Vietnam—Early Progress and Challenges

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World Journal of AIDS 2012年第2期2卷 64-70页

作者： duc Duong bui Fabio Mesquita Thi Nhan Do Masaya Kato Thi Thuy Van Nguyen Thi Minh Thu Nguyen Adrienne Poon Ministry of Health Vietnam Vietnam Authority for HIV/AIDS Control Ha Noi Vietnam World Health Organization Ha Noi Vietnam World Health Organization Ha Noi Vietnam.

Announced in 2010 at the International AIDS Conference in Vienna and pioneered by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization's (WHO) leadership at the global level, Treatment 2.0 is a new approach to the HIV response that encourages innovation, efficiency, and sustainability. building upon WHO and UNAIDS' '3 by 5' Initiative, Treatment 2.0 focuses upon scale-up and universal access of life-saving ART treatment through strategic investments and innovations in five priority pillars that include: 1) Optimize drug regimens, 2) Provide point-of-care (POC) and other simplified diagnostic and monitoring tools, 3) Reduce costs, 4) Adapt service delivery, and 5) Mobilize communities [1-3]. The Treatment 2.0 approach is in line with UNAIDS' 2011-2015 Strategy: Getting to Zero with the vision of, 'Zero New infections;Zero discrimination;and Zero AIDS-related deaths', and as well as the four strategic directions for the health sector response outlined under WHO's Global Health Sector Strategy on HIV/AIDS 2011-2015 [4,5]. At the Sixty-fourth World Health Assembly (WHA) in May 2011, it was formally announced that Vietnam has taken the leadership to pilot Treatment 2.0 in two of its provinces, with support from both the WHO and UNAIDS country offices [6,7]. Given that Vietnam is one of the few countries with a concentrated epidemic to pilot Treatment 2.0, the outcomes and experiences of this initiative can provide valuable insight to other countries who may consider implementation. The objectives of this article are therefore to: 1) Describe the early process for translating Treatment 2.0 concept in Vietnam's context;and 2) Highlight early progress and challenges.

关键词： Treatment 2.0 Vietnam Innovation in Response

A tree-based intelligence ensemble approach for spatial prediction of potential groundwater

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International Journal of Digital Earth 2020年第12期13卷 1408-1429页

作者： Mohammadtaghi Avand Saeid Janizadeh Dieu Tien bui Viet Hoa Pham Phuong Thao T.Ngo Viet-Ha Nhu Faculty of Natural Resources and Marine Sciences Tarbiat Modares UniversityTehranIran Geographic Information Science Research Group Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Environment and Labour Safety Ton Duc Thang UniversityHo Chi Minh CityVietnam Ho Chi Minh City Institute of Resources Geography Vietnam Academy of Science and TechnologyHo Chi Minh CityVietnam Institute of Research and Development Duy Tan UniversityDa NangVietnam Department of Geological-Geotechnical Engineering Hanoi University of Mining and GeologyHanoiVietnam

The objective of this research is to propose and confirm a new machine learning approach of Best-First tree(BFtree),AdaBoost(AB),MultiBoosting(MB),and Bagging(Bag)ensembles for potential groundwater mapping and assessing role of influencing *** Yasuj-Dena area(Iran)is selected as a case *** this regard,a Yasuj-Dena database was established with 362 springs locations and 12 groundwater-influencing factors(slope,aspect,elevation,stream power index(SPI),length of slope(LS),topographic wetness index(TWI),topographic position index(TPI),land use,lithology,distance from fault,distance from river,and rainfall).The database was employed to train and validate the proposed groundwater *** area under the curve(AUC)and statistical metrics were employed to check and confirm the quality of the *** result shows that the BFTree-Bag model(AUC=0.810,kappa=0.495)has the highest prediction performance,followed by the BFTree-MB model(AUC=0.785,kappa=0.477),and the BFTree-MB model(AUC=0.745,kappa=0.422).Compared to the benchmark of Random Forests,the BFTree-Bag model performs better;therefore,we conclude that the BFtree-Bag is a new tool should be used for modeling of groundwater potential.

关键词： Environmental modeling groundwater potential GIS ensemble model decision tree

K-Ar Dating of Fault Gouges from the Red River Fault Zone of Vietnam

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Acta Geologica Sinica(English Edition) 2016年第5期90卷 1653-1663页

作者： bui Hoang Bac NGO Xuan Thanh Yungoo SONG Tetsumaru ITAYA Koshi YAGI KHUONG The Hung NGUYEN Tien Dung Faculty of Geosciences and Geoengineering Hanoi University of Mining and Geology Duc Thang Bac Tu Liem Hanoi Vietnam Department of Earth System Sciences Yonsei University 50 Yonsei-ro Seoul 120-749 Republic of Korea Japan Geochronology Network (NPO) 2-5 Nakashima Naka-ku Okayama 703-8252 Japan Hiruzen Institute for Geology and Chronology Co. Ltd. 2-5 Nakashima Nakaku Okayama 703-8252 Japan

Constraining the timing of fault zone formation is fundamentally important in terms of geotectonics to understand structural evolution and brittle fault *** paper presents the first authigenic illite K-Ar age data from fault gouge samples collected from the Red River Shear Zone at Lao Cai province,*** fault gouge samples were separated into three grain-size fractions（〈0.1 μm,0.1-0.4 μm and 0.4-1.0 μm）.The results show that the K-Ar age values decrease from coarser to finer grain fractions（24.1 to 19.2 Ma）,suggesting enrichment in finer fraction of morerecently grown authigenic *** timing of the fault movement are the lower intercept ages at 0%detrital illite（19.2 ± 0.92 Ma and 19.4 ± 0.49 Ma）.In combination with previous geochronological data,this result indicates that the metamorphism of the Day Nui Con Voi（DNCV） metamorphic complex took place before ca.26.8 *** about 26.8 Ma-25 Ma,the fault strongly acted to cause the rapid exhumation of the rocks along the Red River-Ailoa Shan Fault Zone（RR-ASFZ）.During brittle deformation,the DNCV slowly uplifted,implying weak movement of the *** brittle deformation might have lasted for ca.5 Ma.

关键词： illite K-Ar dating Red River Fault Zone polytype gouge authigenitic