检索结果-南通市图书馆

Thin-shell wormholes and modified Chaplygin gas with relativistic corrections

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2023年第12期75卷 84-96页

作者： m z bhatti z Yousaf m Yousaf Department of mathematics University of the PunjabQuaid-i-Azam CampusLahore-54590Pakistan

In this paper,we analyze thin-shell wormholes from two identical copies of charged static cylindrically symmetric spacetimes using Visser’s‘cut and paste’approach under the influence of f(R,T)gravity Harko,Lobo,Nojiri,and Odintsov(2011,***.D 84,024020).In this scenario,the modified Chaplygin gas supports the exotic matter in the shell which allows,one to examine the dynamics of constructed *** utilize the junction condition to connect the interior and exterior geometries across the hypersurface and calculate different components of the Lanczos equation recently computed by Roza in Rosa(2021,***.D 103,104069).We analyze the stability of the thin-shell wormhole models under linear perturbations while keeping the cylindrical symmetry and also examine the influence of charge on their *** positive quantity of the second derivative of potential at the throat radius might be interpreted as the stability *** find both unstable and stable wormhole solutions for different parameters included in the equation of state and specific forms of considered gravity and illustrate them theoretically as well as *** examine the impact of electric charge on the stability region of a constructed wormhole,which suggests that a wormhole model with a charge may exhibit more stable behavior compared to an uncharged system.

关键词： wormholes gravitation mathematical and relativistic aspects of cosmology

Complexity of charged anisotropic spherically symmetric fluids in f(G)gravity

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2023年第3期75卷 91-104页

作者： z Yousaf m z bhatti m m m Nasir Department of mathematics University of the PunjabQuaid-i-Azam CampusLahore-54590Pakistan

The previous ideology of complexity factor for the dynamical spheres[Herrera et al 2018,***.D,98,104059]is extended for the influence of charge.A dynamical spherically symmetric non-dissipative and dissipative self-gravitating structure is examined in the presence of maxwell f(G)gravity to examine the complexity *** pattern of evolution is studied with the minimal complexity *** complexity factor remains the same for the structure of fluid distribution,while we examine homologous constraints for the most basic evolution *** calculate the structure scalars which play an important role in order to understand the fundamental properties of the *** fluid is geodesic as well as shearing for the dissipative case and there is a large number of *** the non-dissipative fluid distribution,a shear-free,homogeneous and isotropic,geodesic fluid correlates with the evolving homologous and vanishing complexity *** implication of the condition of vanishing complexity factor and stability are discussed at the end.

关键词： gravitation anisotropy complexity hydrodynamics

Effects of multiple shapes for steady flow with transformer oil+Fe_(3)O_(4)+TiO_(2) between two stretchable rotating disks

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2期45卷 373-388页

作者： m.RAHmAN m.TURKYILmAzOGLU z.mUSHTAQ Department of mathematics Mirpur University of Science and TechnologyMirpur 10250Pakistan Department of mathematics Hacettepe UniversityBeytepeAnkara 06532Turkiye

In this study,we examine the effects of various shapes of nanoparticles in a steady flow of hybrid nanofluids between two stretchable rotating *** steady flow of hybrid nanofluids with transformer oil as the base fluid and Fe_(3)O_(4)+TiO_(2)as the hybrid nanofluid is *** shapes of Fe_(3)O_(4)+TiO_(2)hybrid nanofluids,including sphere,brick,blade,cylinder,and platelet,are *** shape exists in the same volume of a *** leading equations(partial differential equations(PDEs))are transformed to the nonlinear ordinary differential equations(ODEs)with the help of similarity *** system of equations takes the form of ODEs depending on the boundary conditions,whose solutions are computed numerically by the bvp4c mATLAB *** outputs are compared with the previous findings,and an intriguing pattern is discovered,such that the tangential velocity is increased for the rotation parameter,while it is decreased by the stretching values because of the lower *** the reaction rate parameter,the concentration boundary layer becomes shorter,and the activation energy component increases the rate at which mass transfers come to the higher disk but have the opposite effect on the bottom *** ranges of various parameters taken into account are Pr=6.2,Re=2,m=1.0,φ_(1)=φ_(2)=0.03,K=0.5,S=-0.1,Br=0.3,Sc=2.0,α_(1)=0.2,γ=0.1,E_(n)=2.0,and q=1.0,and the rotation factor K is within the range of 0 to 1.

关键词： transformer oil Brinkman number skin friction coefficient double rotating disk Nusselt number Sherwood number

Fire resistance evaluation through synthetic fire tests and generative adversarial networks

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第4期18卷 587-614页

作者： Aybike Özyüksel Çiftçioğlu m.z.Naser Department of Civil Engineering Manisa Celal Bayar University45140Türkiye School of Civil&Environmental Engineering and Earth Sciences(SCEEES) Clemson UniversityClemsonSC 29631USA Artificial Intelligence Research Institute for Science and Engineering(AIRISE) Clemson UniversityClemsonSC 29631USA

This paper introduces a machine learning approach to address the challenge of limited data resulting from costly and time-consuming fire experiments by enlarging small fire test data sets and predicting the fire resistance of reinforced concrete *** approach begins by creating deep learning models,namely generative adversarial networks and variational autoencoders,to learn the spatial distribution of real fire *** then use these models to generate synthetic tabular samples that closely resemble realistic fire resistance values for reinforced concrete *** generated data are employed to train state-of-the-art machine learning techniques,including Extreme Gradient Boost,Light Gradient Boosting machine,Categorical Boosting Algorithm,Support Vector Regression,Random Forest,Decision Tree,multiple Linear Regression,Polynomial Regression,Support Vector machine,Kernel Support Vector machine,Naive Bayes,and K-Nearest Neighbors,which can predict the fire resistance of the columns through regression and *** learning analyses achieved highly accurate predictions of fire resistance values,outperforming traditional models that relied solely on limited experimental *** study highlights the potential for using machine learning and deep learning analyses to revolutionize the field of structural engineering by improving the accuracy and efficiency of fire resistance evaluations while reducing the reliance on costly and time-consuming experiments.

关键词： deep learning fire resistance generative adversarial networks machine learning

Dysregulation of RNA modification systems in clinical populations with neurocognitive disorders

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第6期19卷 1256-1261页

作者： Helen m.Knight merve Demirbugen ?z Adriana PerezGrovas-Saltijeral Division of Cells Organisms and Molecular Genetics School of Life Sciences University of Notingham Department of Pharmaceutical Toxicology Faculty of Pharmacy Ankara University

The study of modified RNA known as epitranscriptomics has become increasingly relevant in our understanding of disease-modifying mechanisms. methylation of N6 adenosine(m6A) and C5 cytosine(m5C) bases occur on mRNAs, tRNA, mt-tRNA, and rRNA species as well as non-coding RNAs. With emerging knowledge of RNA binding proteins that act as writer, reader, and eraser effector proteins, comes a new understanding of physiological processes controlled by these systems. Such processes when spatiotemporally disrupted within cellular nanodomains in highly specialized tissues such as the brain, give rise to different forms of disease. In this review, we discuss accumulating evidence that changes in the m6A and m5C methylation systems contribute to neurocognitive disorders. Early studies first identified mutations within FmR1 to cause intellectual disability Fragile X syndromes several years before FmR1 was identified as an m6A RNA reader protein. Subsequently, familial mutations within the m6A writer gene mETTL5, m5C writer genes NSUN2, NSUN3, NSUN5, and NSUN6, as well as THOC2 and THOC6 that form a protein complex with the m5C reader protein ALYREF, were recognized to cause intellectual development disorders. Similarly, differences in expression of the m5C writer and reader effector proteins, NSUN6, NSUN7, and ALYREF in brain tissue are indicated in individuals with Alzheimer’s disease, individuals with a high neuropathological load or have suffered traumatic brain injury. Likewise, an abundance of m6A reader and anti-reader proteins are reported to change across brain regions in Lewy bodies diseases, Alzheimer’s disease, and individuals with high cognitive reserve. m6A-modified RNAs are also reported significantly more abundant in dementia with Lewy bodies brain tissue but significantly reduced in Parkinson’s disease tissue, whilst modified RNAs are misplaced within diseased cells, particularly where synapses are located. In parahippocampal brain tissue, m6A modification is en

关键词： 5-methylcytosine methylation Alzheimer's disease cognitive diseases epitranscriptomics intellectual disability Lewy body diseases N6 adenosine RNA modification

双制式列车接地系统的车-地联合牵引供电计算

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

西南交通大学学报 2024年第3期59卷 501-509页

作者：刘炜杨凌云马庆安李雪飞 bhatti Ashfaque Ahmed 西南交通大学电气工程学院四川成都611730 中车长春轨道客车股份有限公司吉林长春130062

为研究双制式列车在不同供电制式区段下的车体环流和车体—轴端电位分布,针对某型双制式列车构建列车接地系统的链式电路模型,并提出车-地一体化的交、直流区段联合牵引供电计算方法;同时,建立列车接地保护电阻优化模型,并分析2种列车... 详细信息

为研究双制式列车在不同供电制式区段下的车体环流和车体—轴端电位分布,针对某型双制式列车构建列车接地系统的链式电路模型,并提出车-地一体化的交、直流区段联合牵引供电计算方法;同时,建立列车接地保护电阻优化模型,并分析2种列车接地系统配置方案.以国内某条双制式线路为算例进行仿真验证,研究结果表明:方案1相较方案2,列车的车体—轴端电位最大值降低36.58%~41.04%,车体环流最大值降低18.49%~22.97%;并且在方案1中,头尾车保护电阻设置为20 mΩ,可使列车的车体—轴端电位最大值为1.15 V,车体电流最大值为50.30 A,达到抑制车体—轴端电位的最优效果.该车-地一体化的交、直流区段联合牵引供电计算方法可适用于单一供电制式或者多供电制式列车接地系统的分析.

关键词：双制式列车联合牵引供电计算列车接地系统链式电路车体环流

Selection criteria of mPOB-Angola germplasm collection for yield improvement of the oil palm

在线全文

学校读者我要写书评

暂无评论

Oil Crop Science 2024年第1期9卷 20-28页

作者： A.Norziha z.zamri Y.zulkifli A.m.Fadila m.marhalil malaysian Palm Oil Board 6Persiaran InstitusiBandar BaruBangi43000KajangSelangorMalaysia Institute of System Biology Universiti Kebangsaan Malaysia43600BangiSelangorMalaysia

Oil palm germplasm collected from Angola,Africa in 1991 were subjected to genetic variability potential *** collection was planted in the form of open-pollinated families as trials at the malaysian Palm Oil Board(mPOB)Kluang Research Station,Johor,malaysia,in *** palms from 52 families and tenera palms from 44 families of mPOB-Angola were evaluated for their bunch yield and bunch quality *** objectives of this study were to determine the genetic variability among the families and performance of mPOB-Angola germplasm for yield *** analysis of variance(ANOVA)revealed highly significant differences between the dura and tenera families for most of the traits,suggesting the presence of high genetic variability,which is essential for breeding *** the duras,family AGO 02.02 displayed the best yield performance,with a high fresh fruit bunch,oil yield and total economic product at 240.40,29.46 and 37.93 kg palm^(-1)year^(-1),*** for the teneras,family AGO 03.04 recorded the highest FFB yield and oil yield at 249.25 and 45.22 kg palm^(-1)year^(-1),*** that,several families with big fruit sizes or producing a mean fruit weight of 14-17 g were also *** dura and tenera from AGO 01.01 recorded the highest oil to bunch(O/B)of 17.76%and 28.65%,*** findings will facilitate the selection of palms from the mPOB-Angola germplasm for future breeding programmes.

关键词： Oil palm Germplasm Genetic variability Heritability Yield improvement

Greatly enhanced corrosion/wear resistances of epoxy coating for mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

在线全文

学校读者我要写书评

暂无评论

Journal of magnesium and Alloys 2024年第1期12卷 332-344页

作者： z.Y.Xue X.J.Li J.H.Chu m.m.Li D.N.zou L.B.Tong School of metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Advanced Design and manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of mg alloys.

关键词： mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

Rational molecular design of efficient yellow-red dendrimer TADF for solution-processed OLEDs: a combined effect of substitution position and strength of the donors

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1613-1623页

作者： Changfeng Si Dianming Sun Tomas matulaitis David B.Cordes Alexandra m.z.Slawin Eli zysman-Colman Organic Semiconductor Centre EaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsKY169STUK

The development of high-performance solution-processed red organic light-emitting diodes(OLEDs) remains a challenge,particularly in terms of maintaining efficiency at high luminance. Here, we designed and synthesized four novel orange-red thermally activated delayed fluorescence(TADF) dendrimers that are solution-processable: 2GCz BP, 2DPACz BP, 2FBP2GCz and 2FBP2DPACz. We systematically investigated the effect of substitution position and strength of donors on the optoelectronic properties. The reverse intersystem crossing rate constant(kRISC) of the emitters having donors substituted at positions 11and 12 of the dibenzo[a,c]phenazine(BP) is more than 10-times faster than that of compounds substituted having donors substituted at positions 3 and 6. Compound 2DPACz BP, containing stronger donors than 2GCz BP, exhibits a red-shifted emission and smaller singlet-triplet energy splitting, ΔE_(ST), of 0.01 e V. The solution-processed OLED with 10 wt% 2DPACz BP doped in m CP emitted at 640 nm and showed a maximum external quantum efficiency(EQE_(max)) of 7.8%, which was effectively maintained out to a luminance of 1,000 cd m-2. Such a device's performance at relevant display luminance is among the highest for solution-processed red TADF OLEDs. The efficiency of the devices was improved significantly by using 4Cz IPN as an assistant dopant in a hyperfluorescence(HF) configuration, where the 2DPACz BP HF device shows an EQEmaxof 20.0% at λEL of 605 nm and remains high at 11.8% at a luminance of 1,000 cd m-2, which makes this device one of the highest efficiency orange-to-red HF SP-OLEDs to date.

关键词： thermally activated delayed fluorescence solution-processing red OLEDs dibenzo[a,c]phenazine dendrimers

同方期刊数据库