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Biological Community in Submerged Caves and Marine Lakes in ha Long-Cat ba.Area, Vietnam

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Journal of Life Sciences 2015年第11期9卷 541-548页

作者： nguyen Dang Ngai Dau Van Thao Do Cong Thung Le Thi Thuy Dam Duc Tien nguyen Van Quan PhamVan Chien Institute of Marine Environment and Resources Vietnam Academic of Science and Technology Hai Phong City Vietnam

Submerged caves and marine lakes are two iconic and common ecosystems in Ha Long-Cat ba.area. However, their biological characteristics are poorly known since very limited studies have been conducted, The aim of this study was to investigate biodiversity in these ecosystems. Three submerged caves （Hang Sang, Hang Toi and Qua ba.g） and three marine lakes （Dau Be, Ang Du and Qua ba.g） were chosen for study. The results showed that organism communities in submerged caves were abundant with over 142 species found. The popular groups comprised sponge and soft coral which were distributed along the length of the caves. Several species with high economic value were widespread in the caves, including stone crab Myomenippe hardwickii, flower crab Portunus pelagicus, cone snails Trochus pyramis, shoemaker spinefoot Siganus sutor, snapper Lutjanus russellii. Species that permanently live in caves were not detected. In the lakes where water is well exchanged to the sea, coral reefs were found and they usually formed a narrow ba.d around the lakes. Sandy beaches were often observed around the lakes at the depths of 0.5-2 m, containing specialty species as clam （Sanguinolaria diphos）, snout otter clam （Lutraria rhychaena）, sea cucumbers with high density （in Dau Be, Qua ba.g）. There was no coral reef in the enclosed lake （Ang Du） because of low salinity.

关键词： Karst habitat biodiversity organism environment.

Application of Hydrological Model to Simulate Rainfall-Runoff into An Khe Reservoir in the ba.River ba.in, Vietnam

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Journal of Environmental Science and Engineering(A) 2018年第3期7卷 101-107页

作者： nguyen Van Hieu Can Thu Van Vu Minh Cat Ministry of Natural Resources and Environment Ha Noi 100000 Vietnam Thuyloi Universiry Ha Noi 100000 Vietnam Hochiminh City University of Natural Resources and Environment HCM City 700000 Vietnam

The BR （ba.River） ba.in is one of 9 main river ba.ins in Vietnam. In the past 20 years, natural hazards such as flood andinundation have been complex and increased dramatically in both frequency and intensity in the BR ba.in. Recently, there have beenapproximately 198 large and small operating reservoirs which lead to increase natural hazards in the river ba.in. An Khe reservoir,one of big reservoirs in the upstream of the ba.river, impacts significantly on flooding in the downstream. This paper useshydrological model to simulate the flows as a ba.ic for the safety operation of An Khe reservoir in order to prevent the downstreamfloods. The results indicate the Nash-Sutcliffe coefficient higher than 0.8 is stable and reliable parameter.

关键词： ba.river ba.in flood An Khe reservoir hydrographic model rainfall-runoff

Investigation the Dimensional Ratio Effect on the Resonant Properties of Piezoelectric Ceramic Disk

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Journal of Modern Physics 2013年第12期4卷 1627-1631页

作者： Vo Thanh Tung nguyen Trong Tinh Truong Van Chuong nguyen Thi Mai Huong Dang Anh Tuan Le Van Truyen Hue University of Sciences Hue CityVietnam Institutes of Applied Physics and Scientific Instrument Vietnamese Academy of Science and TechnologyHanoiVietnam

In this work, the vibration characteristics of a piezoelectric ceramic disk with different dimensional ratio are studied by simulation method. Computational finite element modeling combined with the computational programs has allowed for the prediction of the effect, the change of diameter-to-thickness ratio on the resonant characteristics, the vibration modes as well as comparing the physic properties of piezoceramics. Three types of piezoelectric materials were chosen, piezoelectric materials (PZT) and Pb-free piezoelectric materials ba.Zr0.2Ti0.8)O3-50(ba..7Ca0.3)TiO3(BZT-50BCT), ba.iO3 for research.

关键词： BZT-50BCT PZT Family Finite Element Modeling Vibration Mode

Application of Remote Sensing and GIS Technology in Mapping Partition Saline Intrusion to Paddy Land:A Case Study at Phu Vang District,Thua Thien Hue Province

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Journal of Agricultural Science and Technology(A) 2017年第B10期7卷 48-59页

作者： nguyen Hoang Khanh Linh Le Ngoc Phuong Quy Truong Do Minh Phuong nguyen Trac ba.An Faculty of Land Resources and Agricultural Environment University of Agriculture and ForestryHue University102 Phung Hung StreetHue 530000Vietnam

Adapting and restricting salinity intrusion in Vietnam is being concerned by more researchers as well as the local *** study aimed to use remote sensing and geographic information system(GIS)technology for mapping paddy areas and salinity intrusion in spring crop 2015 at Phu Vang district,thereby helping precondition for assessing and monitoring changes in salinity intrusion to serve for salinization management in study *** on acquisition imagery,land use map and normalized difference vegetation index(NDVI)were extracted to interpolate the salinity of area by combining the laboratory analysis of collected soil samples from the *** result showed that there were 1,067.107 ha of salinity land area accounting for 10.04%of the rice land in Phu Vang district,where the moderate salinity level was 180.67 ha and low salinity level was 866.431 *** salinity rice land was mainly distributed in Vinh Ha commune,Phu An commune and Phu Dien *** salinity in this area ranged from 0.4 mS/cm to 1.41 mS/cm and the moderate salinity was approximately 0.9 mS/***,this research also showed that the salinity(electrical conductivity)and the development of vegetation(NDVI)were closely related with each other up to 61.4%.

关键词： GIS remote sensing normalized difference vegetation index salinity intrusion paddy land

Arbitrarily structured quantum emission with a multifunctional metalens

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eLight 2023年第1期3卷 75-84页

作者： Chi Li Jaehyuck Jang Trevon ba.loe Tieshan Yang Joohoon Kim Jaekyung Kim Minh nguyen Stefan A.Maier Junsuk Rho Haoran Ren Igor Aharonovich School of Mathematical and Physical Sciences University of Technology SydneyUltimoNSW 2007Australia School of Physics and Astronomy Monash UniversityMelbourneVIC 3800Australia Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Mechanical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Graduate School of Artificial Intelligence Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Physics Imperial College LondonLondon SW72AZUK POSCO-POSTECH-RIST Convergence Research Centre for Flat Optics and Metaphotonics Pohang 37673Republic of Korea National Institute of Nanomaterials Technology(NINT) Pohang 37673Republic of Korea ARC Centre of Excellence for Transformative Meta-Optical Systems University of Technology SydneyUltimoNSW 2007Australia

Structuring light emission from single-photon emitters(SPEs)in multiple degrees of freedom is of great importance for quantum information processing towards higher ***,traditional control of emission from quantum light sources relies on the use of multiple bulky optical elements or nanostructured resonators with limited functionalities,constraining the potential of multi-dimensional *** we introduce the use of an ultrathin polarisation-beam-splitting metalens for the arbitrary structuring of quantum emission at room *** to the complete and independent polarisation and phase control at the single meta-atom level,the designed metalens enables simultaneous mapping of quantum emission from ultra-bright defects in hexagonal boron nitride and imprinting of an arbitrary wavefront onto orthogonal polarisation states of the *** hybrid quantum metalens enables simultaneous manipulation of multiple degrees of freedom of a quantum light source,including directionality,polarisation,and orbital angular *** could unleash the full potential of solid-state SPEs for their use as high-dimensional quantum sources for advanced quantum photonic applications.

关键词： temperature quantum arbitrary

High-dose methylprednisolone pulse therapy for the treatment of patients with severe COVID-19: Results from a prospective observational study

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Journal of Intensive Medicine 2022年第3期2卷 197-198页

作者： Thinh N.Bui Hoang-Anh Ngo Nhat M.Huynh nguyen-Huy Do-Tran Lac Duy Le Thu-Anh nguyen COVID-19 Intensive Care Unit 2 Thu Duc City HospitalThu Duc CityHo Chi Minh CityTam Phu 721400Vietnam Woolcock Institute of Medical Research 298 Kim MaBa DinhHanoi 118000Vietnam Usher Institute Old Medical SchoolUniversity of EdinburghEdinburgh EH89AGUnited Kingdom School of Medicine Vietnam National UniversityDong HoaHo Chi Minh CityDi AnBinh Duong 590000Vietnam Sydney School of Medicine The Faculty of Medicine and HealthThe University of SydneyCamperdownNSW 2050Australia

To the Editor:Recent randomized controlled trials,as well as high-quality systematic reviews and meta-analyses,strongly support the use of corticosteroids in patients with coronavirus disease 2019(COVID-19)who require oxygen support.[1]The use of pulse cor-ticosteroid therapy has been reported in case series and studies,showing significant improvement in patients and a reduction in mortality rate.[2]In this letter,we report the mortality rate among patients with severe COVID-19 receiving pulse corticos-teroids with methylprednisolone(500 mg/day)for≥3 days and≥24 h before intuba.ion(median duration of therapy:3 days)compared with standard of care.

关键词： patients mortality therapy

Music Genre Classification Using DenseNet and Data Augmentation

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Computer Systems Science & Engineering 2023年第10期47卷 657-674页

作者： Dao Thi Le Thuy Trinh Van Loan Chu ba.Thanh nguyen Hieu Cuong Faculty of Information Technology University of Transport and CommunicationsHanoi100000Vietnam School of Information and Communication Technology Hanoi University of Science and TechnologyHanoi100000Vietnam Faculty of Information Technology University of Technology and Education Hung Yen160000Vietnam

It can be said that the automatic classification of musical genres plays a very important role in the current digital technology world in which the creation,distribution,and enjoyment of musical works have undergone huge *** the number ofmusic products increases daily and themusic genres are extremely rich,storing,classifying,and searching these works manually becomes difficult,if not *** classification ofmusical genres will contribute to making this *** research presented in this paper proposes an appropriate deep learning model along with an effective data augmentation method to achieve high classification accuracy for music genre classification using Small Free Music Archive(FMA)data *** Small FMA,it is more efficient to augment the data by generating an echo rather than pitch *** research results show that the DenseNet121 model and data augmentation methods,such as noise addition and echo generation,have a classification accuracy of 98.97%for the Small FMA data set,while this data set lowered the sampling frequency to 16000 *** classification accuracy of this study outperforms that of the majority of the previous results on the same Small FMA data set.

关键词： Music genre classification Small FMA DenseNet CNN GRU data augmentation

Responses of Native Tree Species to Soil Water Stress in a Tropical Forest on Limestone,Vietnam

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Open Journal of Forestry 2015年第7期5卷 711-722页

作者： Le Van Binh nguyen Van Thinh Reinhard Kopp Vo Dai Hai Ralph Mitlohner Department of Tropical Silviculture and Forest Ecology Georg-August-Universitat GottingenGottingenGermany Vietnamese Academy of Forest Sciences Ha NoiVietnam

Forests over limestone in the tropics have received little attention and limestone forests in Vietnam have been overlooked to an even greater extent in terms of tree physiology. In ba.Be National Park, Vietnam, soil water availability in limestone forests seems to be the most limiting factor in the dry season. Therefore, in order to enhance the preliminary knowledge of choosing native tree species for enrichment planting in the restoration zone, characteristics of the 20 native tree species to soil water stress were investigated in a limestone forest. One-ha plot each consisting of twenty-five 20 m × 20 m plots was established in undisturbed forests. All trees ≥ 10 cm DBH were measured in 20 m × 20 m plots, while twenty-five 5 m × 5 m subplots were established in order to sample the regeneration of tree species with a DBH < 10 cm. The Scholander apparatus and freezing point osmometry were used in order to measure the leaf water potential (Ψw) and leaf osmotic potential (Ψπ) of the 20 native tree species, respectively in this study. 61 species belonging to 34 families of all trees with a DBH ≥ 10 cm were recorded in one ha, while 31 species representing 18 families of trees < 10 cm DBH were identified in 625 m2. The 20 species’ leaf water and osmotic potential values revealed significant differences among species. The maximum leaf water potential was not affected by any anticipated sources of variation, while the minimum water potential, however, showed significant variation to soil water stress. The results in the study area emphasized the importance of water factors in influencing tree species distribution;it could be concluded that native species with wide water potential ranges would be better able to withstand water changes and might be thus good candidates for reforestation (enrichment planting) in limestone areas.

关键词： Tropical Limestone Forests Floristic Composition Native Tree Species Leaf Water Potential Leaf Osmotic Potential

Factors Affecting the Households’ Willingness-to-Pay for Wastewater Treatment in Agro-Food Processing Craft Villages, Nhue-Day River ba.in, Vietnam

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Journal of Environmental Protection 2019年第9期10卷 1119-1130页

作者： Tran Thi Thu Trang Roberto F. Rañ ola Jr. nguyen Van Song Department of Natural Resources and Environmental Economics Faculty of Economics and Rural Development Vietnam National University of Agriculture Hanoi Vietnam Department of Agricultural and Applied Economics College of Economics and Management University of the Philippines Los Ba&ntilde os Los Ba&ntilde os Philippines

Industrialization is a major strategy of Vietnam for the development of the countryside. One such program is the promotion of craft villages that have been successful in increasing income levels that are 5 times more than those villages mainly engaged in agricultural production. However, while such programs have brought prosperity to these villages, they have ignored the adverse effects on the environment brought about by the wastewaters from the processing plants. Would these households involved in agro-food processing be willing to pay for the establishment of a wastewater plant to address the environmental problems? What factors would influence their willingness to pay? The results of the study among the selected households in Nhue-Day River ba.in, Vietnam involved in agro-processing showed that the major factors affecting their willingness to pay for the establishment of a wastewater treatment plant are their level of education, quantity of households’ untreated wastewater, presence of young children who are more vulnerable to the adverse effects of pollution, experience of family members getting sick, households’ awareness of benefits from treated wastewater, capacity to pay, access to credit and membership in craft village’s Association. The study recommended that decisions on addressing environmental issues should be participatory to be able to take into consideration the socio-economic conditions of the stakeholders.

关键词： Wastewater Treatment Willingness-to-Pay Craft Villages Ordered Logit Model