检索结果-南通市图书馆

Journal of Semiconductors 2022年第12期43卷 22-31页

作者： Van Nang Lam thi Bich Vu Quang Dat Do thi thanh Xuan Le tien Dai nguyen t-thanh-bao nguyen Hoang tung Do thi tu Oanh nguyen Department of Natural Sciences Hoa Lu UniversityNinh NhatNinh Binh CityViet Nam Institute of theoretical and Applied Research Duy Tan UniversityHanoi 100000Viet Nam Faculty of Natural Sciences Duy Tan UniversityDa Nang 550000Vietnam Institute of Physics Vietnam Academy of Science and Technology10 Dao TanBa DinhHanoiVietnam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCaugiayHanoiVietnam

We report on the synthesis of Sn-doped hematite nanoparticles(Sn-α-Fe_(2)O_(3) NPs)by the hydrothermal *** prepared Sn-α-Fe_(2)O_(3) NPs had a highly pure and well crystalline rhombohedral phase with an average particle size of 41.4 *** optical properties of as-synthesizedα-Fe_(2)O_(3) NPs show a higher bandgap energy(2.40-2.57 eV)than that of pure bulkα-Fe_(2)O_(3)(2.1 eV).By doping Sn intoα-Fe_(2)O_(3) NPs,the Sn-doped hematite was observed a redshift toward a long wavelength with in-creasing Sn concentration from 0%to 4.0%.the photocatalytic activity of Sn-dopedα-Fe_(2)O_(3) NPs was evaluated by Congo red(CR)dye *** degradation efficiency of CR dye using Sn-α-Fe_(2)O_(3) NPs catalyst is higher than that of pureα-Fe_(2)O_(3) *** highest degradation efficiency of CR dye was 97.8%using 2.5%Sn-dopedα-Fe_(2)O_(3) NPs catalyst under visible-light *** results suggest that the synthesized Sn-dopedα-Fe_(2)O_(3) nanoparticles might be a suitable approach to develop a photocatalytic degradation of toxic inorganic dye in wastewater.

关键词： α-Fe_(2)O_(3)nanoparticles Sn Congo red photocatalytic properties photodegradation

Unknown DDoS Attack Detection with Fuzzy C-Means Clustering and Spatial Location Constraint Prototype Loss

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 2181-2205页

作者： thanh-Lam nguyen HaoKao thanh-tuan nguyen Mong-Fong Horng Chin-Shiuh Shieh Department of Electronic Engineering National Kaohsiung University of Science and TechnologyKaohsiung807618Taiwan Department of Electronic and Automation Engineering Nha Trang UniversityNha Trang650000Vietnam

Since its inception,the Internet has been rapidly *** the advancement of science and technology and the explosive growth of the population,the demand for the Internet has been on the *** applications in education,healthcare,entertainment,science,and more are being increasingly deployed based on the ***,malicious threats on the internet are on the rise as *** Denial of Service(DDoS)attacks are among the most common and dangerous threats on the internet *** scale and complexity of DDoS attacks are constantly *** Detection Systems(IDS)have been deployed and have demonstrated their effectiveness in defense against those *** addition,the research of Machine Learning(ML)and Deep Learning(DL)in IDS has gained effective results and significant ***,one of the challenges when applying ML and DL techniques in intrusion detection is the identification of unknown *** attacks,which are not encountered during the system’s training,can lead to misclassification with significant *** this research,we focused on addressing the issue of Unknown Attack Detection,combining two methods:Spatial Location Constraint Prototype Loss(SLCPL)and Fuzzy C-Means(FCM).With the proposed method,we achieved promising results compared to traditional *** proposed method demonstrates a very high accuracy of up to 99.8%with a low false positive rate for known attacks on the Intrusion Detection Evaluation Dataset(CICIDS2017)***,the accuracy is also very high,reaching 99.7%,and the precision goes up to 99.9%for unknown DDoS attacks on the DDoS Evaluation Dataset(CICDDoS2019)*** success of the proposed method is due to the combination of SLCPL,an advanced Open-Set Recognition(OSR)technique,and FCM,a traditional yet highly applicable clustering *** has yielded a novel method in the field of unknown attack *** further expands the trend of applying DL and M

关键词： Cybersecurity DDoS unknown attack detection machine learning deep learning incremental learning convolutional neural networks(CNN) open-set recognition(OSR) spatial location constraint prototype loss fuzzy c-means CICIDS2017 CICDDoS2019

GLOBAL BOUND ON tHE GRADIENt OF SOLUtIONS tO p-LAPLACE tYPE EQUAtIONS WItH MIXED DAtA

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第4期44卷 1394-1414页

作者： Minh-Phuong tRAN the-Quang tRAN thanh-Nhan nguyen Applied Analysis Research Group Faculty of Mathematics and StatisticsTon Duc Thang UniversityHo Chi Minh CityVietnam nguyen Huu Huan High School Thu Duc CityVietnam Group of Analysis and Applied Mathematics Department of MathematicsHo Chi Minh City University of EducationVietnam

In this paper,the study of gradient regularity for solutions of a class of elliptic problems of p-Laplace type is *** particular,we prove a global result concerning Lorentz-Morrey regularity of the non-homogeneous boundary data problem:-div((s^(2)+|▽u|^(2)p-2/2)▽u)=-div(|f|^(p-2)f)+g inΩ,u=h in■Ω,with the(sub-elliptic)degeneracy condition s∈[0,1]and with mixed data f∈L^(p)(Q;R^(n)),g∈Lp/(p-1)(Ω;R^(n))for p∈(1,n).this problem naturally arises in various applications such as dynamics of non-Newtonian fluid theory,electro-rheology,radiation of heat,plastic moulding and many *** on the idea of level-set inequality on fractional maximal distribution functions,it enables us to carry out a global regularity result of the solution via fractional maximal *** to the significance of M_(α)and its relation with Riesz potential,estimates via fractional maximal functions allow us to bound oscillations not only for solution but also its fractional derivatives of orderα.Our approach therefore has its own interest.

关键词： gradient estimates p-Laplace quasilinear elliptic equation fractional maximal operators Lorentz-Morrey spaces

Prevalence and risk factors associated with long COVID symptoms in children and adolescents in a southern province of Vietnam

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of tropical Medicine 2024年第3期17卷 119-128,I0001,I0002页

作者： Huynh Ngoc Linh nguyen the tan Le thi Minh thu nguyen tu Loan nguyen thi to Uyen Le thanh thao trang truong thanh Nam Doan Hoang Phu Faculty of Medicine Ca Mau Medical CollegeCa Mau 98000Vietnam Ca Mau Obstetrics and Pediatrics Hospital Ca Mau 98000Vietnam Faculty of Basic Science and Public Health Dong Thap Medical CollegeDong Thap 81000Vietnam Graduate University of Sciences and technology Vietnam Academy of Science and TechnologyHa Noi 10000Vietnam Community Public Health Research Program School of Public HealthWalailak UniversityNakhon Si Thammarat 80160Thailand Faculty Public Health Can Tho University of Medicine and PharmacyCan Tho City 94000Vietnam Doctoral Program in Health Sciences College of Graduate StudiesWalailak UniversityNakhon Si Thammarat 80160Thailand

Objective:to investigate the prevalence and risk factors associated with long COVID symptoms among children and adolescents who have recovered from ***:this study applied a cross-sectional approach within community settings in a southern province of Vietnam.A structured questionnaire featuring socio-demographic information and common long COVID symptoms was *** correlation coefficients assessed associations among pairs of long COVID ***,multivariable logistic regression models were performed to investigate the risk factors of long COVID in recovered COVID-19 children and ***:Among 422 participants,39.3%reported long COVID symptoms,with a prevalence of 45.2%(SD=0.5)in children and 22.2%(SD=0.4)in *** symptoms reported were cough 34.6%(SD=0.5),fatigue 20.6%(SD=0.4),shortness of breath 10.9%(SD=0.3),and lack of appetite 6.6%(SD=0.3).Concerning risk factors of long COVID,a higher risk was observed among demographic groups,including girls(OR 1.25,95%CI 1.15-1.37;Pto adolescents(OR 1.24,95%CI 1.12-1.37;Pt individuals(OR 1.14,95%CI 1.02-1.27;P=0.018,reference:healthy weight),and participants without any COVID-19 vaccination(OR 1.36,95%CI 1.20-1.54;Pto those who have received two ***,patients with a COVID-19 treatment duration exceeding two weeks also had a higher risk of long COVID(OR 1.32,95%CI 1.09-1.60;P=0.003)than those who recovered less than seven ***:the insights from this study provide crucial guidance for predicting the factors associated with the occurrence of long COVID in pediatric patients,contributing to strategic interventions aimed at mitigating the long COVID risks among children and adolescents in Vietnam.

关键词： Long COVID Prevalence Risk factors Children Adolescent Vietnam

Some Mean Convergence theorems for the Maximum of Normed Double Sums of Banach Space Valued Random Elements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1727-1740页

作者： Andrew ROSALSKY Le Van thanh nguyen thi tHUY Department of Statistics University of FloridaGainesvilleFL 32611-8545USA Department of Mathematics Vinh UniversityVinhNghe AnViet Nam High School for Gifted Students Vinh UniversityVinhNghe AnViet Nam

In this correspondence,we establish mean convergence theorems for the maximum of normed double sums of Banach space valued random *** of the results pertain to random elements which are *** expand and improve a number of particular cases in the literature on mean convergence of random elements in Banach *** of the main contributions of the paper is to simplify and improve a recent result of Li,Presnell,and Rosalsky[Journal of Mathematical Inequalities,16,117–126(2022)].A new maximal inequality for double sums of M-dependent random elements is proved which may be of independent *** sharpness of the results is illustrated by four examples.

关键词： Double sum mean convergence Rademacher type p Banach space Banach space valued random element M-dependent random elements

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： N.D.nguyen t.N.nguyen Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and technology Kien Giang UniversityChau Thanh 92000Viet Nam

this study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(tD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBt)

A comparative study on kinetics and dynamics of two dump truck lifting mechanisms using MAtLAB simscape

在线全文

学校读者我要写书评

暂无评论

theoretical & Applied Mechanics Letters 2024年第2期14卷 146-156页

作者： thong Duc Hong Minh Quang Pham Son Cong tran Lam Quang tran truong thanh nguyen Faculty of transportation Engineering Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh City 700000Vietnam Vietnam National University Ho Chi Minh City(VNU-HCM) Ho Chi Minh City 700000Vietnam Industrial Maintenance training Center Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh City 700000Vietnam

In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been *** mechanical and hydraulic simulation models are established using MAtLAB Simscape to analyze their kinetics and dynamics in the lifting and holding *** simulation findings are compared to the analytical calculation results in the steady state,and both methods show good *** the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model ***,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting *** established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system *** is crucial in studying,designing,and optimizing the structure of hydraulic-mechanical systems.

关键词： Dump truck Lifting mechanism Hydraulic MAtLAB Simscape Kinetic dynamic analysis

Influence of different land-use types on selected soil properties related to soil fertility in A Luoi District,thua thien Hue,Vietnam

在线全文

学校读者我要写书评

暂无评论

Soil Ecology Letters 2024年第1期6卷 131-140页

作者： Khoa Phuc nguyen tan trong tran Huy Dinh Le Phuong thuy nguyen Hien thao thi Pham Dien thanh nguyen Ngu Huu nguyen University of Agriculture and Forestry Hue UniversityHue CityThua Thien Hue 52000Vietnam School of Biotechnology Tan Tao UniversityTan Duc ECityDuc HoaLong An850000Vietnam

Land use type affects the physicochemical properties of *** value of OM and tN is high in acacia *** acidity of soil is considered a serious constraint for *** cash crops are acacia,cassava,banana,rice and *** fertility is affected by land-use types and land management,which exacerbates soil erosion and various other forms of soil degradation in the mountainous regions of *** study was conducted in A Luoi District,thua thien Hue,Vietnam to identify the effects of land-use types on specific soil physicochemical characteristics related to soil *** physicochemical properties,such as organic matter(OM),total nitrogen(tN),total phosphorous(tP),and K+were significantly affected by land-use *** results showed that the soils were sandy in rice but clay loam for acacia and *** mean bulk density value of acacia soil was significantly greater than that of other *** were higher in the acacia soils than those in the rice,maize,and banana *** OM content was significantly higher in the acacia,cassava,and banana soils than those in the rice and maize *** mean of exchangeable K+in the rice soil was higher compared to those in other soils and was affected by land-use *** high exchangeable acidity content in the soils was probably due to intensive ***,both land use type and management did not affect the CEC ***,the inappropriate land use caused the disturbance of soil physicochemical properties,indicating that the conditions of rice and maize soils are becoming worse than acacia ***,lowering the intensity of cultivation,adopting incorporated soil fertility management,and applying organic fertilizer should preserve the existing conditions and enhance soil properties.

关键词： Land-use types soil characteristics soil frility suitable crop Vietnam

Comparative Chemical Research in Essential Oils from Six Apiaceae Species Growing in the Northern Region of Vietnam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2024年第7期93卷 1677-1687页

作者： nguyen Quang Hung nguyen thanh tung nguyen Phuong Hanh Chu thi thu Ha nguyen thi Nhung nguyen thai An Vu Xuan Giang Luong Van Hao Oleh Koshovyi Ain Raal Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology(VAST)Cau GiayHa Noi100000Viet Nam Graduate University of Science and technology Vietnam Academy of Science and Technology(VAST)Cau GiayHa Noi100000Viet Nam Department of Pharmacognosy Faculty of Pharmacognosy and Traditional MedicineHanoi University of PharmacyHoan KiemHa Noi100000Viet Nam Sa Pa Research Center of Medicinal Materials National Institute of Medicinal MaterialsDien Bien PhuSa PaLao Cai330000Viet Nam Institute of Pharmacy Faculty of MedicineUniversity of TartuTartu50411Estonia

Our study aimed to compare the essential oil(EO)concentration and composition of several Apiaceae species growing in the Northern region of *** yields of EOs from materials ranged from 0.03%(root EO of Angelica acutiloba and aerial parts EO of Heracleum bivittatum)-0.27%(leaf EO of Xyloselinum vietnamense).Gas chromatography-mass spectrometry(GC-MS)allowed the identiﬁcation of 74 components in the EOs of six Apiaceae species,making up 94.4%–100.0%of the *** EO from Angelica acutiloba,(Z)-ligustilide accounted for an extremely large proportion(94.9%).EO of Angelica pubescens was dominated by six character-istic components includingα-pinene(21.5%),β-phellandrene(18.1%),p-cymene(12.2%),3-methylnonane(8.7%),o-cymene(8.1%),and D-sylvestrene(6.2%).the EO from Cryptotaenia japonica was characterized by high amounts ofα-selinene(48.7%),β-selinene(23.7%),and trans-β-farnesene(5.4%).the EOs from leaves and stems of Xyloselinum vietnamense were characterized by high concentrations of sabinene(69.8%and 33.8%),4-terpineol(8.7%and 7.4%)andβ-pinene(4.0%and 6.5%)while EOs from aerial parts and root of Xylo-selinum leonidii comprise four characteristic monoterpenes includingα-pinene(28.2%and 52.8%),β-pinene(7.9%and 10.3%),β-phellandrene(7.6%and 15.3%),and sabinene(3.0%and 4.1%).Additionally,cryptone is also one of the major components in the EO of Xyloselinum leonidii(13.2%in the aerial parts oil and 2.8%in the root oil).In the EOs isolated from the aerial parts and root of Heracleum bivittatum,α-pinene(22.5%and 70.2%)andβ-pinene(43.2%and 20.0%)were the predominant *** appeared in the EO from aerial parts of Heracleum bivittatum with a relatively high concentration(13.5%)while bornyl acetate(5.1%)was also one of the main components in the EO from its aerial parts but was not detected in other Apiaceae species in the present *** databases help identify and control the quality of plant material studied from the family Apiaceae growing in Vietnam.

关键词： Apiaceae essential oil terpenoids gaschromatography-mass spectrometry

One-loop contributions for h→ℓℓγ and e−e+→hγ in the U(1)_(B−L) extension of the standard model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第5期48卷 23-49页

作者： tran Dzung tri thanh Huy nguyen Khiem Hong Phan Institute of Fundamental and Applied Sciences Duy Tan UniversityHo Chi Minh City 700000Vietnam Faculty of Natural Sciences Duy Tan UniversityDa Nang City 550000Vietnam VNUHCM-University of Science 227 Nguyen Van CuDistrict 5Ho Chi Minh CityVietnam

We present one-loop contributions for h→ℓℓγ with ℓ=νe,μ,τ,e,μ and e−e+→hγ in the U(1)_(B−L) extension of the standard model. In the phenomenological results, the signal strengths for h→ℓℓγ at the Large Hadron Collider and for e−e+→hγ at future lepton colliders are analyzed in the physical parameter space for both the vector and chiral B−L models. We found that the contributions from the neutral gauge boson Z′ to the signal strengths are rather small. Consequently, the effects will be difficult to probe at future colliders. However, the impacts of charged Higgs and CP-odd Higgs in the chiral B−L model on the signal strengths are significant and can be measured with the help of the initial polarization beams at future lepton colliders.

关键词： Higgs phenomenology one-loop Feynman integrals analytic methods for quantum field theory dimensional regularization future lepton colliders