检索结果-南通市图书馆

Higgs-like(pseudo)scalars in AdS_(4),marginal and irrelevant deformations in CFT_(3),and instantons on S^(3)

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4期48卷 68-81页

作者： M.Naghdi Department of Physics Faculty of Basic SciencesUniversity of IlamIlamIran

Employing a 4-form ansatz of 11-dimensional supergravity over a non-dynamical AdS_(4)×S^(7)/Z_(k)background and setting the internal space as an S1 Hopf fibration on CP3,we obtain a consistent ***(pseudo)scalars,in the resulting scalar equations in Euclidean AdS_(4)space,may be considered to arise from(anti)M-branes wrapping around the internal directions in the(Wick-rotated)skew-whiffed M2-brane background(as the resulting theory is for anti-M2-branes),thus realizing the modes after swapping the three fundamental representations 8_(s),8_(c),and 8_(v) of SO(8).Taking the backreaction on the external and internal spaces,we obtain the massless and massive modes,corresponding to exactly marginal and marginally irrelevant deformations on the boundary CFT3,***,we obtain a closed solution for the bulk equation and compute its correction with respect to the background ***,considering the Higgs-like(breathing)mode m^(2)=18,having all supersymmetries as well as parity and scale-invariance broken,solving the associated bulk equation with mathematical methods,specifically the Adomian decomposition method,and analyzing the behavior near the boundary of the solutions,we realize the boundary duals in the SU(4)×U(1)-singlet sectors of the ABJM ***,introducing the new dual deformationΔ_(+)=3,6 operators made of bi-fundamental scalars,fermions,and U(1)gauge fields,we obtain the SO(4)-invariant solutions as small instantons on a three-sphere with the radius at infinity,which correspond to collapsing bulk bubbles leading to big-crunch singularities.

关键词： AdS_(4)/CFT_(3)correspondence scalar equations in AdS_(4) instantons marginal and irrelevant operators (anti)M-branes

Credit Card Fraud Detection Using Improved Deep Learning Models

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 1049-1069页

作者： Sumaya S.Sulaiman Ibraheem Nadher Sarab M.Hameed Computer Science Department Al-Mustansiriya UniversityBaghdad10001Iraq Computer Science Department University of BaghdadBaghdad10001Iraq faculty of basic education Al-Mustansiriya UniversityBaghdad10001Iraq

Fraud of credit cards is a major issue for financial organizations and *** fraudulent actions become more complex,a demand for better fraud detection systems is *** learning approaches have shown promise in several fields,including detecting credit card ***,the efficacy of these models is heavily dependent on the careful selection of appropriate *** paper introduces models that integrate deep learning models with hyperparameter tuning techniques to learn the patterns and relationships within credit card transaction data,thereby improving fraud *** deep learning models:AutoEncoder(AE),Convolution Neural Network(CNN),and Long Short-Term Memory(LSTM)are proposed to investigate how hyperparameter adjustment impacts the efficacy of deep learning models used to identify credit card *** experiments conducted on a European credit card fraud dataset using different hyperparameters and three deep learning models demonstrate that the proposed models achieve a tradeoff between detection rate and precision,leading these models to be effective in accurately predicting credit card *** results demonstrate that LSTM significantly outperformed AE and CNN in terms of accuracy(99.2%),detection rate(93.3%),and area under the curve(96.3%).These proposed models have surpassed those of existing studies and are expected to make a significant contribution to the field of credit card fraud detection.

关键词： Card fraud detection hyperparameter tuning deep learning autoencoder convolution neural network long short-term memory resampling

Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BIOCELL 2024年第4期48卷 559-569页

作者： YARA ALZGHOUL HALA J.BANI ISSA AHMAD K.SANAJLEH TAQWA ALABDUH FATIMAH RABABAH MAHA AL-SHDAIFAT EJLAL ABU-EL-RUB FATIMAH ALMAHASNEH RAMADA R.KHASAWNEH AYMAN ALZU’BI HUTHAIFA MAGABLEH Department of basic Medical Sciences Faculty of MedicineYarmouk UniversityIrbidJordan

Mesenchymalstemcells(MSCs)*** the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart *** can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental *** from various sources differ in their regenerative and therapeutic abilities for cardiovascular *** this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

关键词： Bone marrow mesenchymal stem cells Adipose tissue mesenchymal stem cells Dental pulp stem cells Umbilical cord mesenchymal stem cells Cardiomyocytes Regeneration Myocardial infarction Mesenchymal stem cells Differentiation Immunomodulation

Dynamics of a rotating ring-stiffened sandwich conical shell with an auxetic honeycomb core

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 963-982页

作者： S.JAHANGIRI A.GHORBANPOUR ARANI Z.KHODDAMI MARAGHI Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan ***Iran faculty of Engineering Mahallat Institute of Higher EducationMahallat ***Iran

The free vibration analysis of a rotating sandwich conical shell with a reentrant auxetic honeycomb core and homogenous isotropic face layers reinforced with a ring support is *** shell is modeled utilizing the first-order shear deformation theory(FSDT)incorporating the relative,centripetal,and Coriolis accelerations alongside the initial hoop tension created by the *** governing equations,compatibility conditions,and boundary conditions are attained using Hamilton’s *** trigonometric functions,an analytical solution is derived in the circumferential direction,and a numerical one is presented in the meridional direction via the differential quadrature method(DQM).The effects of various factors on the critical rotational speeds and forward and backward frequencies of the shell are *** present work is the first theoretical work regarding the dynamic analysis of a rotating sandwich conical shell with an auxetic honeycomb core strengthened with a ring support.

关键词： free vibration conical shell rotating shell ring support auxetic honeycomb

Effects of high glucose and severe hypoxia on the biological behavior of mesenchymal stem cells at various passages

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2024年第4期16卷 434-443页

作者： Fatimah Almahasneh Ejlal Abu-El-Rub Ramada R Khasawneh Rawan Almazari Department of basic Medical Sciences Faculty of MedicineYarmouk UniversityIrbid 21163Jordan

BACKGROUND Mesenchymal stem cells(MSCs)have been extensively studied for therapeutic potential,due to their regenerative and immunomodulatory *** passage and stress factors may affect the biological characteristics of MSCs,but the details of these effects have not been recognized *** To investigate the effects of stress factors(high glucose and severe hypoxia)on the biological characteristics of MSCs at different passages,in order to optimize the therapeutic applications of *** In this study,we investigated the impact of two stress conditions;severe hypoxia and high glucose on human adipose-tissue derived MSCs(hAD-MSCs)at passages 6(P6),P8,and ***,senescence and apoptosis were evaluated measuring WST-1,senescence-associated beta-galactosidase,and annexin V,*** Cells at P6 showed decreased proliferation and increased apoptosis under conditions of high glucose and hypoxia compared to control,while the extent of senescence did not change significantly under stress *** P8 hAD-MSCs cultured in stress conditions had a significant decrease in proliferation and apoptosis and a significant increase in senescence compared to counterpart cells at *** cultured in high glucose at P10 had lower proliferation and higher senescence than their counterparts in the previous passage,while no change in apoptosis was *** the other hand,MSCs cultured under hypoxia showed decreased senescence,increased apoptosis and no significant change in proliferation when compared to the same conditions at *** These results indicate that stress factors had distinct effects on the biological processes of MSCs at different passages,and suggest that senescence may be a protective mechanism for MSCs to survive under stress conditions at higher passage numbers.

关键词： Mesenchymal stem cells High glucose Hypoxia Stressful microenvironment Serial passage Senescence Apoptosis

Stability analysis of a time-delayed Van der Pol–Helmholtz–Duffing oscillator in fractal space with a non-perturbative approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 22-31页

作者： Yusry O El-Dib Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The time-delayed fractal Van der Pol–Helmholtz–Duffing(VPHD)oscillator is the subject of this paper,which explores its mechanisms and highlights its stability *** time-delayed technologies are currently garnering significant attention,the focus of this research remains crucially relevant.A non-perturbative approach is employed to refine and set the stage for the system under *** innovative methodologies introduced yield an equivalent linear differential equation,mirroring the inherent nonlinearities of the ***,the incorporation of quadratic nonlinearity into the frequency formula represents a cutting-edge *** analytical solution's validity is corroborated using a numerical *** conditions are ascertained through the residual Galerkin ***,it is observed that the delay parameter,in the context of the fractal system,reverses its stabilizing influence,impacting both the amplitude of delayed velocity and the *** analytical solution's precision is underscored by its close alignment with numerical ***,the study reveals that fractal characteristics emulate damping *** its applicability across diverse nonlinear dynamical systems,this non-perturbative approach emerges as a promising avenue for future research.

关键词： Van der Pol-Helmholtz-Duffing oscillator fractal space time-delay non-perturbative approach stability analysis El-Dib's frequency formula

Neural and Behavioral Measures of Stress-induced Impairment in Error Awareness and Post-error Adjustment

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2024年第7期40卷 937-951页

作者： Na Hu Quanshan Long Xiaoxi Wang Quan Li Qing Li Antao Chen School of Preschool and Special education Kunming UniversityKunming 650214China faculty of education Yunnan Normal UniversityKunming 650214China College of Teacher education Qujing Normal UniversityQujing 655099China Key Laboratory of Cognition and Personality of Ministry of education Faculty of PsychologySouthwest UniversityChongqing 400715China School of Psychology Shanghai University of SportShanghai 200438China

Exposure to stress negatively affects error processing,but the impact of stress on error awareness remains to be *** the present study,we examined the temporal dynamics of error awareness and post-error adjustment following acute ***-nine healthy men were randomly assigned to the control(n=26)or stress group(n=23).After stress induction,participants completed the error awareness task,and their brain activity was assessed by *** to the control group,the stress group demonstrated lower error awareness accuracy and smaller Pe(error positivity)and ΔPe amplitudes following aware error responses,which indicated impairment of error awareness following ***,the stress group had lower accuracy in post-aware error responses than in post-unaware error responses and the control group,which indicated poor post-error adjustment following *** results showed a stress effect on sequential stages of error *** induces impaired error identification,which further generates maladaptive post-error performance.

关键词： Acute stress Error awareness Post-error adjustment Error positivity

Transient responses of double-curved sandwich two-layer shells resting on Kerr's foundations with laminated three-phase polymer/GNP/fiber surface and auxetic honeycomb core subjected to the blast load

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第5期35卷 222-247页

作者： Nguyen Thi Hai Van Thi Hong Nguyen Researcher&Lecturer Faculty of Industrial EducationThe University of Danang-University of Technology and Education48 Cao ThangDanang550000Viet Nam Researcher&Lecturer Faculty of Mechanical EngineeringThuyloi University175 Tay SonDong DaHanoi100000Viet Nam

This work uses refined first-order shear theory to analyze the free vibration and transient responses of double-curved sandwich two-layer shells made of auxetic honeycomb core and laminated three-phase polymer/GNP/fiber surface subjected to the blast *** of the two layers that make up the double-curved shell structure is made up of an auxetic honeycomb core and two laminated sheets of three-phase polymer/GNP/*** exterior is supported by a Kerr elastic foundation with three *** key innovation of the proposed theory is that the transverse shear stresses are zero at two free surfaces of each *** contrast to previous first-order shear deformation theories,no shear correction factor is ***'s exact solution was used to treat the double-curved shell problem with a single title boundary,while the finite element technique and an eight-node quadrilateral were used to address the other boundary *** ensure the accuracy of these results,a thorough comparison technique is employed in conjunction with credible *** problem model's edge cases allow for this kind of *** study's findings may be used in the post-construction evaluation of military and civil works structures for their ability to sustain explosive *** addition,this is also an important basis for the calculation and design of shell structures made of smart materials when subjected to shock waves or explosive loads.

关键词： Blast load Two-layer shell Polymer/GNP/Fiber surface Auxetic honeycomb Shear connectors

Research on Risk Identification and Industrial Governance of Digital education Products Based on Data Annotation Technology

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第3期21卷 273-282页

作者： Tong Lili Zeng Jia Di Ying Wang Nan faculty of education Beijing Normal University Beijing 100875China China Unicom Beijing 102211China

The social transformation brought aboutby digital technology is deeply impacting various *** education products, with core technologiessuch as 5G, AI, IoT (Internet of Things),etc., are continuously penetrating areas such as teaching,management, and evaluation. Apps, miniprograms,and emerging large-scale models are providingexcellent knowledge performance and flexiblecross-media output. However, they also exposerisks such as content discrimination and algorithmcommercialization. This paper conducts anevidence-based analysis of digital education productrisks from four dimensions: “digital resourcesinformationdissemination-algorithm design-cognitiveassessment”. It breaks through corresponding identificationtechnologies and, relying on the diverse characteristicsof governance systems, explores governancestrategies for digital education products from the threedomains of “regulators-developers-users”.

关键词： digital education products industry governance risk identification