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Tropical Cyclone Research and Review 2018年第3期7卷 179-192页

作者： tho dat tran DUC TRUONG DINH QUANG TRI DOAN QUANG TIEN tran The National Economics University Vietnam Sustainable Management of Natural Resources and Environment Research Group Faculty of Environment and Labour SafetyTon Duc Thang University National Center for Hydrometeorological Forecasting

Understanding impacts of typhoons due to storm surge plays an important role in reducing damage in coastal *** study used the SWAN wave model to simulate the typhoon waves and the SuWAT model to simulate storm surge and inundation caused by Typhoon Xangsane in 2006 which landed in the Central Coast of Vietnam from Nghe An to Phu Yen *** wind-pressure f ield was calculated by the Fujita’s model and reanalysis data were inputted to the SWAN and SuWAT *** simulated results of the typhoon wave showed that Typhoon Xangsane caused 5-7 m height waves in the coastal areas with a radius of 600 *** results of the storm surge combined with the simulations of wind,pressure,wave,and tide in the coastal areas were estimated at 2 *** simulated and calculated results of storm surge and inundation maps will help the decision makers in the Committee for Natural Disaster Prevention and Control to reduce the impacts of natural disasters induced to storm surge in the near future.

关键词： Typhoon Xangsane storm surge SWAN SuWAT

Persistence in tillage decisions: Aggregate data analysis

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International Soil and Water Conservation Research 2019年第2期7卷 109-118页

作者： dat Q.tran Lyubov A.Kurkalova University of Arkansas at Fayetteville AR 72701Department of Agricultural Economics and AgribusinessUSA Can tho University Department of Hydraulic EngineeringVietnam 1601 E.Market St. GreensboroNC27411North Carolina A&T State UniversityDepartment of EconomicsUSA 1601 E.Market St. GreensboroNC27411North Carolina A&T State UniversityDepartment of Energy and Environmental SystemsUSA

The Emission Gap Report 2013 from the United Nations Environment Program showed that adopting conservation tillage such as no-till,as an alternative to conventional tillage,contributes significantly to climate change mitigation through carbon ***,substantial amounts of soil carbon are lost when farmers interrupt continuous use of conservation tillage with conventional *** tillage is spreading,but little is known about the behavioral persistence in tillage *** address the gap in the literature,we estimate county-specific Markov models of tillage-crop choices,and use the predicted probabilities of alternative two-and three-year tillage rotations to evaluate spatial variation and temporal persistence in conservation tillage adoption for the state of lowa (U.S).We find that the county-average probabilities of continuous conservation tillage range between 0.133 and 0.295,and vary significantly among crop *** also find a statistically strong positive effect of the incidence of the highly erodible land on the county-average use of continuous conservation *** results underscore the importance of dynamic modeling for understanding behavioral persistence in tillage decisions,and the interdependence between farmers' crop and tillage rotations.

关键词： Aggregate data Continuous conservation tillage Markov chain model Crop rotations Highly erodible land

Ru@RuO2 Core-Shell Nanorods: A Highly Active and Stable Bifunctional Catalyst for Oxygen Evolution and Hydrogen Evolution Reactions

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Energy & Environmental Materials 2019年第3期2卷 201-208页

作者： Rongzhong Jiang dat T.tran Jiangtian Li Deryn Chu Sensors and Electron Devices Directorate U.S.Army Research Laboratory2800 Powder Mill RoadAdelphiMD 20783-1197USA

Ru@RuO2 core-shell nanorods were successfully synthesized by heat-treating Ru nanorods with air oxidation through an accurate control of the temperature and time. The structure, composition, dimension, and adsorption property of the core-shell nanorods were well characterized with XRD and TEM. The catalytic activity and stability were electrochemically evaluated with a rotating disk electrode, a rotating ring-disk electrode, and chronopotentiometric methods. The Ru@RuO2 nanorods reveal excellent bifunctional catalytic activity and robust stability for both oxygen evolution reaction(OER) and hydrogen evolution reaction(HER). The overpotentials for OER and HER are 320 m V and 137 m V at the current density of10 m A cm-2, respectively. The catalytic activity of Ru@RuO2 nanorods for OER is 6.5 times higher than that of the state-of-the-art catalyst IrO2 according to the catalytic current density measured at 1.60 V(versus RHE).The catalytic activity of Ru@RuO2 nanorods for HER is comparable to 40%Pt/C by comparing the catalytic current densities at à0.2 V.

关键词： bifunctional catalyst core-shell hydrogen evolution reaction oxygen evolution reaction Ru@RuO2

Assessment of cortical bone fatigue using coded nonlinear ultrasound

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Chinese Physics B 2021年第9期30卷 274-283页

作者： Duwei Liu Boyi Li Dongsheng Bi tho N.H.T.tran Yifang Li Dan Liu Ying Li Dean Ta Center for Biomedical Engineering School of Information Science and TechnologyFudan UniversityShanghai 200433China Academy for Engineering and Technology Fudan UniversityShanghai 200433China Human Phenome Institute Fudan UniversityShanghai 200433China

Bone fatigue accumulation is a factor leading to bone fracture,which is a progressive process of microdamage deteriorating under long-term and repeated *** the microdamage of the early stage in bone is difficult to be investigated by linear ultrasound,the second harmonic generation method in nonlinear ultrasound technique is employed in this paper,which is proved to be more sensitive to *** solve the deficiency that the second harmonic component is easily submerged by noise in traditional nonlinear measurement,a weighted chirp coded sinusoidal signal was applied as the ultrasonic excitation,while pulse inversion is implemented at the receiving *** effectiveness of this combination to improve the signal-to-noise ratio has been demonstrated by in vitro *** fatigue loading experiments were conducted on the cortical bone plate in vitro for microdamage *** was a significant increase in the slope of the acoustic nonlinearity parameter with the propagation distance(increased by 8%and 24%respectively)when the bone specimen was at a progressive level of *** results indicate that the coded nonlinear ultrasonic method might have the potential in diagnosing bone fatigue.

关键词： nonlinear ultrasonic Lamb wave bone fatigue chirp code pulse inversion

Anti-inflammatory effects of fatty acids isolated from Chromolaena odorata

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Asian Pacific Journal of Tropical Medicine 2011年第10期4卷 760-763页

作者： tran Thi Hong Hanh Dan Thi Thuy Hang Chau Van Minh Nguyen Tien dat Institute of Marine Biochemistry Vietnam Academy of Science and Technology(VAST)

Objective:To identify inhibitors of nitric oxide production and NF-κB activity from Chromolaena odorata（***）.Methods:The compounds isolated from the aerial parts of *** by bioassay-guided fractionation were investigated for their inhibitory effects on the NO production and NF-κB activity in LPS-stimulated RAW264.7 ***:Six fatty acids （S）-coriolic acid（1）,（S）-coriolic acid methyl ester（2）,（5）-15,16-didehydrocoriolic acid（3）,（S）- 15,16-didehydrocoriolic acid methyl ester（4）,linoleamide（5） and linolenamide（6） were isolated. All compounds inhibited the NO production at concentrations consistent with those required for NF-κB *** 2 was the most active with the IC50 values of 5.22 and 5.73μM. The addition of a double bond in the fatty chain decreased the inhibitory effects while the methyl esterification increased the ***:The fatty acid components in *** with NF-κB inhibitory activity could explain the anti-inflammation property of this plant in traditional *** study could also contribute to the better use of *** for human health care.

关键词： Chromolaena odorata Asteraceae Fatty acid NF-κB Nitric oxide

Amplitude modulation excitation for cancellous bone evaluation using a portable ultrasonic backscatter instrumentation

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Chinese Physics B 2022年第11期31卷 106-114页

作者： Boyi Li Chengcheng Liu Xin Liu tho N.H.T.tran Ying Li Dan Li Dongsheng Bi Duwei Liu Dean Ta Academy for Engineering and Technology Fudan UniversityShanghai 200433China The Center for Biomedical Engineering Fudan UniversityShanghai 200433China The State Key Laboratory of Medical Neurobiology Fudan UniversityShanghai 200433China

The ultrasonic backscatter(UB)has the advantage of non-invasively obtaining bone density and structure,expected to be an assessment tool for early diagnosis *** former UB measurements were based on exciting a short single-pulse and analyzing the ultrasonic signals backscattered in *** study aims to examine amplitude modulation(AM)ultrasonic excitation with UB measurements for predicting bone *** AM multiple lengths excitation and backscatter measurement(AM-UB)functions were integrated into a portable ultrasonic instrument for bone *** apparent integrated backscatter coefficient in the AM excitation(AIB_(AM))was evaluated on the AM-UB *** correlation coefficients of the AIB_(AM) estimating volume fraction(BV/TV),structure model index(SMI),and bone mineral density(BMD)were then *** correlations(|R|=0.82-0.93,pdations in AM-UB measurement were that the avoided length(T1)should be lower than AM excitation length,and the analysis length(T2)should be enough long but not more than AM excitation *** authors conducted an AM-UB measurement for cancellous bone *** the AM excitation length could substantially enhance AIB_(AM) values stability with varying analyzed *** study suggests the portable AM-UB instrument with the integration of real-time analytics software that might provide a potential tool for osteoporosis early screening.

关键词： ultrasonic backscatter measurement amplitude modulation osteoporosis bone diagnosis

An improved CRNN for Vietnamese Identity Card Information Recognition

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Computer Systems Science & Engineering 2022年第2期40卷 539-555页

作者： Trinh Tan dat Le tran Anh Dang Nguyen Nhat Truong Pham Cung Le Thien Vu Vu Ngoc Thanh Sang Pham Thi Vuong Pham The Bao Information Science Faculty Sai Gon UniversityHCM City700000Vietnam Faculty of Electrical&Electronics Engineering University of TechnologyHCM City700000Vietnam

This paper proposes an enhancement of an automatic text recognition system for extracting information from the front side of the Vietnamese citizen identity(CID)***,we apply Mask-RCNN to segment and align the CID card from the ***,we present two approaches to detect the CID card’s text lines using traditional image processing techniques compared to the EAST ***,we introduce a new end-to-end Convolutional Recurrent Neural Network(CRNN)model based on a combination of Connectionist Temporal Classification(CTC)and attention mechanism for Vietnamese text recognition by jointly train the CTC and attention objective functions *** length of the CTC’s output label sequence is applied to the attention-based decoder prediction to make the final label *** process helps to decrease irregular alignments and speed up the label sequence estimation during training and inference,instead of only relying on a data-driven attention-based encoder-decoder to estimate the label sequence in long *** may directly learn the proposed model from a sequence of words without detailed *** evaluate the proposed system using a real collected Vietnamese CID card dataset and find that our method provides a 4.28%in WER and outperforms the common techniques.

关键词： Vietnamese text recognition OCR CRNN BLSTM attention mechanism joint CTC-Attention

Particle Size Effect on Shear Properties of Bottom Ash Added-Geocomposite Soil

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Journal of Civil Engineering and Architecture 2011年第8期5卷 748-753页

作者： Do Thanh Hai tran Xuan tho Department of Geotechnical Engineering Faculty of Civil Engineering Ho Chi Minh City University of Technology Vietnam

It is well known that the finer particle of cementing material has more pozzolanic reaction than the coarser. This paper investigates the shear properties of geocomposite soil with various particle sizes of bottom ash. The geocomposite soil （GCS） in this study consists of dredged soil, bottom ash and cement for recycling dredged soil and bottom ash. Three different particle sizes of bottom ash passing No. 4 sieve, No. 40 sieve, and No. 140 sieve were added into soil mixtures, namely as GCS 4, GCS 40, and GCS 140, respectively. These bottom ashes have the same chemical component except for different particle sizes. Several mixtures were prepared with various contents of bottom ash ranging from 0 to 100% at 50% intervals by the weight of dry dredged soil. In this study, several series of unconfined compression test were carried out on the mixtures with various curing times. It is found that the unconfined compressive strength is a function of curing time and bottom ash content. For the curing time less than 28 days, the GCS 4 has higher unconfined compressive strength than the GCS 40 and GCS 140 due to the interlocking effect and friction between the particles with angular shape of coarse bottom ash. For the curing time larger than 28 days, the GCS 140 has higher strength due to the pozzolanic reaction. However, the ratios of secant modulus to unconfined compressive strength of three mixtures are almost the same, and in range of （46-100）, regardless of mixing condition and curing time.

关键词： Bottom ash particle size unconfined compressive strength shear strength.

Anti-inflammatory effects of alkaloid enriched extract from roots of Eurycoma longifolia Jack

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Asian Pacific Journal of Tropical Biomedicine 2019年第1期9卷 18-23页

作者： Dao Thi Thanh Hien tran Phi Long tran Phuong Thao Jeong-Hyung Lee Duong Thu trang Nguyen Thi Thu Minh Pham Van Cuong Do Thi Ngoc Lan Nguyen Hai Dang Nguyen Tien dat Deparment of Traditional Pharmacy Hanoi University of Pharmacy Department of Biochemistry College of Natural Sciences Kangwon National University Advanced Center for Bio-organic Chemistry Institute of Marine Biochemistry Vietnam Academy of Science and Technology National Institute of Drug Quality Control Center for Research and Technology transfers

Objective: To examine the in vitro and in vivo anti-inflammatory effects of the alkaloid enriched extract(ELA) from the roots of Eurycoma longifolia. Methods: The in vitro antiinflammatory effects of ELA were evaluated by examining its inhibitory activities against nitric oxide(NO) production and inducible nitric oxide synthase(iN OS) and cyclooxygenase2(COX-2) expressions in lipopolysaccharide(LPS)-stimulated RAW264.7 cells. The level of NO produced in the culture media was determined by Griess method. The i NOS and COX-2 protein expressions were analyzed by Western blot. The in vivo effect of ELA was evaluated on LPS-induced septic shock in mice model. Mice mortality was monitored for5 days after injection of LPS. The chemical contents of the ELA were determined by using various chromatographic and spectroscopic techniques. Results: The ELA was found to exhibit a significant anti-inflammatory effect in both in vitro and in vivo models. The results demonstrated that ELA dose-dependently inhibited LPS-induced NO production as well as the protein iN OS and COX-2 expressions. In the septic shock model, ELA dose-dependently protected mice from LPS-induced mortality. Further study on the isolated components of ELA indicated that 9,10-dimethoxycanthin-6-one may contribute significantly to the antiinflammatory effects of the extract. Conclusions: These results suggest that ELA exhibits the anti-inflammatory activity via suppression of pro-inflammatory mediators such as NO, iN OS,and COX-2 and protects mice from LPS-induced mortality in septic shock model.

关键词： Eurycoma longifolia Anti-inflammation Alkaloid 9,10-dimethoxycanthin-6-one

An Analytical Approach for Nonlinear Buckling Analysis of Torsionally Loaded Sandwich Carbon Nanotube Reinforced Cylindrical Shells with Auxetic Core

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Advances in Applied Mathematics and Mechanics 2023年第2期15卷 468-484页

作者： Dang Thuy Dong Nguyen Thi Phuong Vu Hoai Nam Le Ngoc Ly Nguyen Van Tien Vu Minh Duc tran Quang Minh Vu tho Hung Nguyen Thi Huong Giang Faculty of Civil Engineering University of Transport TechnologyHanoi 100000Vietnam Graduate School of Advanced Science and Engineering Hiroshima University1-4-1 KagamiyamaHigashi-HiroshimaHiroshima 739-8527Japan Faculty of Fundamental Science for Engineering University of Transport TechnologyHanoi 100000Vietnam

The main aim of this paper is to present an analytical approach on the postbuckling for torsionally loaded sandwich carbon nanotube(CNT)reinforced cylindrical shells with the auxetic *** considered shells consist of three layers,external and internal CNT reinforced layers,and the auxetic lattice core made by isotropic *** homogenization model for honeycomb auxetic lattice core is utilized,and the equilibrium equations are formulated based on the nonlinear Donnell’s thin shell theory with von Karman geometrical *** three terms of deflection are considered,the Airy’s stress function and Galerkin’s method are utilized,the explicit expression of critical buckling of torsionally loaded shells and load-deflection expression of postbuckling states are *** effects of two carbon nanotube reinforced layers,the auxetic core layer,the volume fraction of carbon nanotube on the torsional buckling behavior are examined and remarked.

关键词： Nonlinear postbuckling carbon nanotube reinforced composite cylindrical shell torsion auxetic core