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Examination of n-t_(9) conditions required by n=50,82,126 waiting points in r-process

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Communications in theoretical Physics 2021年第10期73卷 147-157页

作者： nguyen Duy Ly nguyen ngoc Duy nguyen Kim Uyen vinh n t pham Faculty of Fundamental Sciences Vanlang UniversityHo Chi Minh City 700000Vietnam Department of Physics Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Physics Ho Chi Minh City University of EducationHo Chi Minh City 700000Vietnam

We examined the conditions of neutron density(n) and temperature(t9) required for the n = 50, 82,and 126 isotopes to be waiting points(WP) in the r-process. the nuclear mass based on experimental data presented in the AME2020 database(AME and AME ± Δ) and that predicted using FRDM,WS4, DZ10, and KtUY models were employed in our estimations. We found that the conditions required by the n = 50 WP significantly overlap with those required by the n = 82 ones, except for the WS4 model. In addition, the upper(or lower) bounds of the n-t9 conditions based on the models are different from each other due to the deviations in the two-neutron separation *** standard deviations in the nuclear mass of 108 isotopes in the three n = 50, 82, and 126 groups are about rms = 0.192 and 0.434 Me V for the pairs of KtUY-AME and WS4-KtUY models,respectively. We found that these mass uncertainties result in a large discrepancy in the nn-t_(9) conditions, leading to significant differences in the conditions for simultaneously appearing all the three peaks in the r-process abundance. the newly updated FRDM and WS4 calculations can give the overall conditions for the appearance of all the peaks but vice versa for their old versions in a previous study. the change in the final r-process isotopic abundance due to the mass uncertainty is from a few factors to three orders of magnitude. therefore, accurate nuclear masses of the r-process key nuclei, especially for 76 Fe,81Cu,127Rh,132Cd,192Dy, and 197tm, are highly recommended to be measured in radioactive-ion beam facilities for a better understanding of the r-process evolution.

关键词： neutron capture r-process nuclear mass isotopic abundance precise mass measurement

new Results on System of Generalized Quasi-Ky Fan Inequalities with Set-Valued Mappings in topological Semilattice Spaces

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Journal of Systems Science & Complexity 2016年第6期29卷 1585-1595页

作者： nGUYEn the vinh pham thi Hoai Department of Mathematics University of Transport and Communications School of Applied Mathematics and Informatics University of Science and Technology

Under new assumptions,this paper obtains some extended versions of Ky Fan type inequality for a family of C-continuous set-valued mappings in the setting of topological *** obtained results are new and different from the corresponding known results in the *** special cases of the main result are also *** examples are given to illustrate the results.

关键词： C△-quasiconvex (quasiconcave) Fan-Browder fixed point theorem set-valued Ky Faninequality topological semilattice upper (lower) C-continuous.

A new Inertial Self-adaptive Gradient Algorithm for the Split Feasibility Problem and an Application to the Sparse Recovery Problem

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Acta Mathematica Sinica,English Series 2023年第12期39卷 2489-2506页

作者： nguyen the vinh pham thi HOAI Le Anh DUnG Yeol Je CHO Department of Mathematical Analysis University of Transport and Communications3 Cau Giay StreetHanoiVietnam Department of Applied Mathematics School of Applied Mathematics and InformaticsHano University of Science and Technology1 Dai Co Viet RoadHanoiVietnam Department of Mathematics and Informatics Hanoi University of Education136 Xuan ThuyCau GiayHanoiVietnam Department of Mathematics Education Gyeongsang National UniversityJinju52828Republicof Korea

In this paper,by combining the inertial technique and the gradient descent method with Polyak's stepsizes,we propose a novel inertial self-adaptive gradient algorithm to solve the split feasi-bility problem in Hilbert spaces and prove some strong and weak convergence theorems of our method under standard *** examine the performance of our method on the sparse recovery prob-lem beside an example in an infinite dimensional Hilbert space with synthetic data and give some numerical results to show the potential applicability of the proposed method and comparisons with related methods emphasize it further.

关键词： Split feasibility problem CQ algorithm Hilbert space sparse recovery problem

EP Aquarii:A new Picture of the Circumstellar Envelope

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Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： pham t.nhung Do t.Hoai Pierre Darriulat pham tuan-Anh pham n.Diep nguyen B.ngoc tran t.thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

new analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

关键词： stars AGB and post-AGB-(stars) circumstellar matter-radio lines stars

A High-order Coupled Compact Integrated RBF Approximation Based Domain Decomposition Algorithm for Second-order Differential Problems

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Computer Modeling in Engineering & Sciences 2015年第4期104卷 251-304页

作者： C.M.t.tien n.pham-Sy n.Mai-Duy C.-D.tran t.tran-Cong Computational Engineering and Science Research Centre Faculty of HealthEngineering and SciencesThe University of Southern QueenslandToowoombaQueensland 4350Australia

this paper presents a high-order coupled compact integrated RBF(CC IRBF)approximation based domain decomposition(DD)algorithm for the discretisation of second-order differential *** Schwarz DD algorithms,including one-level additive/multiplicative and two-level additive/multiplicative/hybrid,are *** CCIRBF based DD algorithms are analysed with different mesh sizes,numbers of subdomains and overlap sizes for Poisson *** convergence analysis shows that the CCIRBF two-level multiplicative version is the most effective algorithm among various schemes employed ***,the present CCIRBF two-level method converges quite rapidly even when the domain is divided into many subdomains,which shows great promise for either serial or parallel *** practical tests,we then incorporate the CCIRBF into serial and parallel two-level multiplicative *** numerical examples,including those governed by Poisson and navier-Stokes equations are analysed to demonstrate the accuracy and efficiency of the serial and parallel algorithms implemented with the *** results show:(i)the CCIRBF-Serial and-Parallel algorithms have the capability to reach almost the same solution accuracy level of the CCIRBF-Single domain,which is ideal in terms of computational calculations;(ii)the CCIRBF-Serial and-Parallel algorithms are highly accurate in comparison with standard finite difference,compact finite difference and some other schemes;(iii)the proposed CCIRBF-Serial and-Parallel algorithms may be used as alternatives to solve large-size problems which the CCIRBF-Single domain may not be able to deal *** ability of producing stable and highly accurate results of the proposed serial and parallel schemes is believed to be the contribution of the coarse mesh of the two-level domain decomposition and the CCIRBF *** is noted that the focus of this paper is on the derivation of highly accurate serial and parallel algorithms

关键词： Coupled compact integrated RBF (CCIRBF) Schwarz domain decomposition one-level two-level coarse meshes additive multiplicative hybrid serial parallel colouring technique Poisson equation naiver-Stokes equation liddriven cavity

Patterns of hepatitis B virus exposure and associated predictors in Vietnam: A crosssectional study

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Asian Pacific Journal of tropical Medicine 2020年第12期13卷 535-541页

作者： Minh C.Duong Phuc V.D.Le Oanh n.K.pham Hien D.t.pham toan B.nguyen Hai t.Phan School of Public Health and Community Medicine University of New South WalesSydneyNew South WalesAustralia MEDIC Medical Center Ho Chi Minh CityVietnam Hospital for tropical Diseases Ho Chi Minh CityVietnam pham ngoc thach University of Medicine Ho Chi Minh CityVietnam

Objective:to examine the magnitude of isolated anti-HBc and other HBV serological patterns and associated predictors among adults seeking general health check-up at a large health center in ***:All 564 outpatients seeking general health checkup between January 2016 and December 2016 were asked to undertake HBV surface antigen,surface antibody,IgG and IgM core antibody(anti-HBc total),platelet counts,and liver function *** administered questionnaire was used to collect information regarding demography,in-house sources of infection,lifestyle,health condition and treatment,and HBV ***:Male gender(P=0.043),age(P=0.000),living in urban areas(P=0.040),HBV vaccination status(P=0.033),and ALt(P=0.040) were associated with isolated *** infection was associated with HBV vaccination status(P=0.001),ALt levels(P=0.010),ASt levels(P=0.020),and platelet counts(P=0.007).Past/resolved HBV infection was associated with ASt levels(P=0.005),ALt levels(P=0.014),and age(P=0.000).Conclusions:Isolated anti-HBc is quite *** of isolated anti-HBc include male gender,living in rural areas,and HBV *** prevalence of isolated anti-HBc also increases with *** timely detect occult HBV infection and prevent transmission,anti-HBc testing should be included in the health check-up for high risk individuals and screening program where HBV nucleic acid test is not *** prevent transmission,clinicians need to pay more attention on those who are at risk of having isolated anti-HBc and closely follow-up patients with isolated anti-HBc and educate them about the prevention of HBV infection.

关键词： prevention seeking Vietnam

Design of a two-dimensional Recursive Filter Using the Bees Algorithm

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International Journal of Automation and computing 2010年第3期7卷 399-402页

作者： D.t.pham Ebubekir Koc Manufacturing Engineering Centre Cardiff University Cardiff CF24 3AA UK

this paper presents the first application of the bees algorithm to the optimisation of parameters of a two-dimensional （2D） recursive digital filter. the algorithm employs a search technique inspired by the foraging behaviour of honey bees. the results obtained show clear improvement compared to those produced by the widely adopted genetic algorithm （GA）.

关键词： Bees algorithm swarm intelligence optimisation two-dimensional digital filter design.

Performances of a new sustainable and durable dry beam-column joints under cyclic and impact loads

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Science China(technological Sciences) 2023年第2期66卷 282-300页

作者： HAO Hong nGO tuan t. pham thong M. LI HuaWei Center for Infrastructural Monitoring and Protection School of Civil and Mechanical EngineeringCurtin UniversityBentley WA 6102Australia the Faculty of Engineering and technology Quy Nhon UniversityBinh Dinh 590000Viet Nam Guangzhou University-Curtin University Joint Research Center for Structural Monitoring and Protection against Multi-Dynamic Hazards School of Civil EngineeringGuangzhou UniversityGuangzhou 510006China

this study investigated the performances of a new type of precast beam-column joint subjected to earthquake and impact *** sustainability and durability considerations,new materials such as corrosion-resistant fibre reinforced polymer(FRP)bolts and reinforcements,fibre reinforced concrete(FRC),and geopolymer concrete(GPC)were used to construct the *** examine the resilience,durability,sustainability,and multi-hazard resistance capacities,both cyclic and pendulum impact tests were carried *** experimental results demonstrated that the proposed precast joints had the comparable or even better performances as compared with the traditional monolithic joints under cyclic and impact *** simulations using ABAQUS were also adopted to determine the optimal values of the concrete-end-plate(CEP)thickness for the proposed dry joints and to further quantify other response parameters which could not be obtained during the test,e.g.,stress distribution,energy absorption,and stress *** on the influences of various parameters on joint performances under different loading conditions was also presented in this study.

关键词： multi-hazards cyclic loads impact loads FRP bolts FRP reinforcements geopolymer concrete fibre-reinforced concrete dry joints ABAQUS

Compensation of Zn substitution and secondary phase controls effective mass and weighted mobility in In and Ga co-doped ZnO material

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Journal of Materiomics 2021年第4期7卷 742-755页

作者： Oanh Kieu truong Le Anh tuan thanh pham ngoc Kim pham trang Huyen Cao pham truong Huu nguyen Dung Van Hoang Hanh Kieu thi ta Dai Cao truong Hoa thi Lai thuy Dieu thi Ung vinh Cao tran thang Bach Phan aboratory of Advanced Materials University of ScienceHoChiMinh City700000Viet Nam Vietnam national University HoChiMinh City700000Viet Nam Faculty of Physics and Engineering Physics University of ScienceHoChiMinh City700000Viet Nam Faculty of Materials Science and technology University of ScienceHoChiMinh City700000Viet Nam Center for Innovative Materials and Architectures(InOMAR) HoChiMinh CityViet Nam Institute of Materials Science Vietnam Academy of Science and TechnologyHanoi100000Viet Nam

Conductivity s and thermal conductivity k are directly related to carrier concentration while Seebeck coefficient S is inversely proportional to carrier ***,improving thermoelectric(tE)performance is ***,the first-time analysis of secondary phase-controlled tE performance in terms of density-of-state effective mass m*d,weighted mobility mw and quality factor B is discussed in ZnO *** results show that the secondary spinel phase Ga2O_(3)(ZnO)9 not only impacts on k but also on s and S at high temperature,while the effect of carrier concentration seem to be dominant at low *** the high-spinel-segregation sample,a compensation of dopant atoms from the spinel to substitutional sites in the ZnO matrix at high temperature leads to a low decreased rate of temperaturedependent m**** compensation process also induces a band sharpening,a small mw reduction,and a large B *** a result,In and Ga co-doped ZnO bulk with the highest spinel segregation achieves the greatest PF improvement by 112.8%,owing to enhanced Seebeck coefficient by 110%as compared to the good Zn-substitution sample.

关键词： thermoelectrics In and Ga co-Doped ZnO Secondary phase Zn substitution DOS effective Mass Weighted mobility