检索结果-南通市图书馆

Chinese Jou.n.l of Mechanical Engineering 2021年第6期34卷 51-62页

作者： M.nuño J.Bühring M.n.Rao K.-u.Schröder Institute of Structural Mechanics and Lightweight Design RWTH Aachen UniversityWüllnerstraβe 752072 AachenGermany

Sandwich structures possess a high bending stiffness compared to monolithic structures with a similar *** makes them very suitable for lightweight applications,where high stiffness to weight ratios are *** common manufacturing methods of sandwich structures involve adhesive bonding of the core material with the ***,adhesive bonding is prone to delamination,a failure mode that is often difficult to *** paper presents the results of delamination testing of fully additive manufactured(AM)AlSi10Mg sandwich structures with pyramidal lattice truss core using Laser Powder Bed Fusion(LPBF).The faces and struts are 0.5 mm thick,while the core is 2 mm *** inclination of the struts is 45°.To characterise the bonding strength,climbing drum peel tests and out-of-plane tensile tests are *** formulas are derived to predict the expected failure loads and *** analytics and tests are supported by finite element(FE)*** the analytic approach,design guidelines to avoid delamination in AM sandwich structures are *** study presents a critical face sheet thickness to strut diameter ratio for which the structure can *** ratio is mainly influ.n.ed by the inclination of the *** peel tests resulted in face yielding,which can also be inferred from the analytics and *** out-of-plane tensile tests didn’t damage the structure.

关键词： Additive Manufacturing Sandwich Structures Pyramidal Lattice Core

Analysis of Power in an Argon Filled Pulsed Dielectric Barrier Discharge

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2013年第7期15卷 635-639页

作者： u.n.PAL Pooja GuLATI Ram PRAKASH Mahesh KuMAR V.SRIVASTAVA S.KOnAR Microwave Tubes Division CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI)Pilani Rajasthan-333031 India Birla Institute of Technology (BIT) Mesra Ranchi Jharkhand-835215 India

In this paper an argon filled coaxial dielectric barrier discharge （DBD） has been studied to understand the detail of power transfer from a unipolar square pulse to plasma during discharge. A dielectric barrier discharge based diffuse pulse discharge and its electrical charac-teristics are investigated. A quartz coaxial DBD tube filled at different pressures is used in the experiment. A unipolar pulse voltage of different peak voltages and frequ.n.ies has been applied to the discharge electrodes for the generation of microdischarges. Two current pulses are used for two consecutive discharges per applied voltage pulse. The second discharge, which occurs at the falling flank of the voltage pulse, is induced by the charges stored on the dielectric barrier during the first discharge. It has been deduced that the power supplied to ignite the first discharge is partly stored to ignite the second discharge when the applied voltage decays. This process ul- timately leads to much improved power transfer to the plasma. The knowledge obtained from dynamic processes of the DBDs in the discharge gap explains qu.n.itatively the mechanism of ignition, development and extinction of the DBDs.

关键词： DBD non-equilibrium plasma non-thermal plasma diffuse pulse discharge,microdischarges

Dual solutions in MHD stagnation-point flow of Prandtl fluid impinging on shrinking sheet

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2014年第7期35卷 813-820页

作者： n.S.AKBAR Z.H.KHAn R.u.HAQ S.nADEEM Department of Basic Science & Humanities College of Electrical & Mechanical Engineering(CEME) National University of Sciences and Technology Islamabad 46000 Pakistan School of Mathematical Sciences Peking University Department of Mathematics University of Malakand Khyber Pakhtunktwo 18800 Pakistan Department of Mathematics Quaid-i-Azam University Islamabad 44000 Pakistan

The present article investigates the dual nature of the solution of the magneto- hydrodynamic （MHD） stagnation-point flow of a Prandtl fluid model towards a shrinking surface. The self-similar nonlinear ordinary differential equations are solved numerically by the shooting： method. It is found that the dual solutions of the flow exist for cer- tain values of tile velocity ratio parameter. The special case of the first branch solutions （the classical newtonian fluid model） is compared with the present numerical results of stretching flow. The results are found to be in good agreement. It is also shown that the boundary layer thickness for the second solution is thicker than that for the first solution.

关键词： stagnation-point flow shrinking sheet Prandtl fluid magnetohydrody-namic (MHD) dual solution shooting method

unilateral rnurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neuropathology and behavioral deficits in parkinsonian rats withα-synucleinopathy

在线全文

学校读者我要写书评

暂无评论

neural Regeneration Research 2024年第9期19卷 2057-2067页

作者： Bismark Gatica-Garcia Michael J.Bannon Irma Alicia Martínez-Dávila Luis O.Soto-Rojas David Reyes-Corona Lourdes Escobedo Minerva Maldonado-Berny ME Gutierrez-Castillo Armando J.Espadas-Alvarez Manuel A.Fernandez-Parrilla Ju.n.u.Mascotte-Cruz CP Rodríguez-Oviedo Irais E.Valenzuela-Arzeta Claudia Luna-Herrera Francisco E.Lopez-Salas Jaime Santoyo-Salazar Daniel Martinez-Fong Departamento de Fisiología Biofísica y NeurocienciasCentro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico Department of Pharmacology Wayne State University School of MedicineDetroitMIUSA Laboratorio de Patogénesis Molecular Carrera Médico CirujanoFacultad de Estudios Superiores IztacalaUniversidad Nacional Autónoma de MéxicoTlalnepantla de BazMéxico Red de Medicina para la Educación y Desarrollo y la Investigación Científica de Iztacala(Red MEDICI) Carrera Médico CirujanoFacultad de Estudios Superiores IztacalaUniversidad Nacional Autónoma de MéxicoTlalnepantla de BazMéxico nanoparticle Therapy Institute AguascalientesMéxico Departamento de Biociencias e Ingeniería Centro Interdisciplinario de Investigaciones y Estudios sobre Medio Ambiente y DesarrolloInstituto Politécnico NacionalCiudad de MéxicoMéxico Escuela nacional de Medicina y Homeopatía Instituto Politécnico NacionalCiudad de MéxicoMéxico Departamento de Fisiología Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico Departamento de Biología Molecular y Biotecnología Instituto de Investigaciones BiomédicasUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMéxico Departamento de Física Centro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico Programa de nanociencias y nanotecnología Centro de Investigación y de Estudios AvanzadosCiudad de MéxicoMéxico

Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-*** nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rnurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 *** study found that rnurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced ***,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the *** addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia *** effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor *** results show that unilateral rnurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor *** neurotrophic astrocytes and

关键词： A1 astrocytes A2 astrocytes gene therapy microglia motor deficits nanoparticles neurodegeneration neuroinflammation senescence α-synuclein aggregates

The Effect of Fibre Length on Flexural and Dynamic Mechanical Properties of Pineapple Leaf Fibre Composites

在线全文

学校读者我要写书评

暂无评论

Jou.n.l of Renewable Materials 2020年第7期8卷 833-843页

作者： A.A.Mazlan M.T.H.Sultan S.n.A.Safri n.Saba A.u.M.Shah M.Jawaid Department of Aerospace Engineering Faculty of EngineeringUniversiti Putra MalaysiaSerdangSelangor Darul Ehsan43400 UPMMalaysia Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products(INTROP)SerdangSelangor Darul Ehsan43400 UPMMalaysia Aerospace Malaysia Innovation Centre(944751-A) Prime Minister’s DepartmentMIGHT Partnership HubJalan Impact63000 CyberjayaMalaysia

The present paper deals with the effect of loading different pineapple leaf fibre(PALF)length(short,mixed and long fibres)and their reinforcement for the fabrication of vinyl ester(VE)*** of PALF/VE composites was investigated through three-point bending flexural testing and viscoelastic(dynamic)mechanical properties through dynamic mechanical analysis(DMA).DMA results revealed that the long PALF/VE composites displayed better mechanical,damping factor and dynamic properties as compared to the short and mixed PALF/VE *** flexural strength and modulus of long PALF/VE composites were 113.5 MPa and 14.3 GPa,*** storage(E′)and loss(E″)moduli increased to 2000 MPa and 225 MPa respectively for PALF/VE *** result analysis indicated that increasing the length of the reinforcement fibre results in satisfactory mechanical performance and dynamic properties of composites.

关键词： Pineapple leaf fibre vinyl ester resin flexural strength dynamical mechanical properties damping factor

Structural, electronic, and optical properties of ZnO_(1-x)Se_x alloys using first-principles calculations

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

Chinese Physics B 2013年第8期22卷 581-588页

作者： Muhammad Rashid Fayyaz Hussain Muhammad Imran S A Ahmad n A noor M u Sohaib S M Alay-e-Abbas Department of Physics Simulation Laboratory the Islamia University of Bahawalpur63100 Pakistan Department of Physics University of the Punjab Quaid-e-Azam Campus54590 Lahore Pakistan Lahore Development Authority 54590 Lahore Pakistan Department of Physics GC University FaisalabadAllama Iqbal Road Faisalabad 38000 Pakistan

The structural, electronic, and optical properties of binary ZnO, ZnSe compounds, and their ternary ZnOl_xSex alloys are computed using the accurate full potential linearized augmented plane wave plus local orbital （FP-LAPW ＋ lo） method in the rocksalt （B 1） and zincblende （B3） crystallographic phases. The electronic band structures, fundamental energy band gaps, and densities of states for ZnO1_xSex are evaluated in the range 0 〈 x 〈 1 using Wu-Cohen （WC） generalized gradient approximation （GGA） for the exchange-correlation potential. Our calculated results of lattice parameters and bulk modulus reveal a nonlinear variation for pseudo-binary and their ternary alloys in both phases and show a considerable deviation from Vegard＇s law. It is observed that the predicted lattice parameter and bulk modulus are in good agreement with the available experimental and theoretical data. We establish that the composition dependence of band gap is semi-metallic in B1 phase, while a direct band gap is observed in B3 phase. The calculated density of states is described by taking into account the contribution of Zn 3d, O 2p, and Se 4s, and the optical properties are studied in terms of dielectric functions, refractive index, reflectivity, and energy loss function for the B3 phase and are compared with the available experimental data.

关键词： density functional theory alloys structural electronic optical properties

A Statistical Mechanical Analysis on the Bound State Solution of an Energy-Dependent Deformed Hulthén Potential Energy

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2019年第9期71卷 1127-1138页

作者： B.C.Lütfüoglu A.n.Ikot u.S.Okorie A.T.ngiangia Department of Physics Faculty of ScienceAkdeniz University07058AntalyaTurkey Department of Physics Faculty of ScienceUniversity of Hradec KraloveRokitanskeho6250003Hradec KraloveCzechia Department of Physics Theoretical Physics GroupUniversity of Port HarcourtChobaPort HarcourtNigeria Department of Physics Akwa Ibom State UniversityIkot AkpadenP.M.B.1167UyoNigeria

In this article, we investigate the bound state solution of the Klein Gordon equation under mixed vector and scalar coupling of an energy-dependent deformed Hulthén potential in D dimensions. We obtain a transcendental equation after we impose the boundary conditions. We calculate energy spectra in four different limits and in arbitrary dimension via the newton-Raphson method. Then, we use a statistical method, namely canonical partition function, and discuss the thermodynamic properties of the system in a comprehensive way. We find out that some of the thermodynamic properties overlap with each other, some of them do not.

关键词： Klein-Gordon equation energy-dependent deformed Hulthén potential energy bound state solution thermodynamic properties

Effect of natural and anthropogenic acidifi cation on aluminium distribution in forest soils of two regions in the Czech Republic

在线全文

学校读者我要写书评

暂无评论

Jou.n.l of Forestry Research 2021年第1期32卷 363-370页

作者： Lenka Pavlů LubošBorůvka Ondřej Drábek Antonín nikodem Department of Soil Science and Soil Protection Faculty of AgrobiologyFood and Natural ResourcesCzech University of Life Sciences PraguePragueCzechia

To elucidate the dynamics of aluminium(Al),an element potentially toxic and strongly aff ected by acidifi cation processes,in soils,we selected two regions that were similar in relief,soil types,and vegetation cover but diff ered markedly in their history of acid precipitation:the JizerskéMountains(anthropogenically acidifi ed)and the novohradskéMountains(naturally acidifi ed)in the Czech *** levels of Al forms(exchangeable and organically bound)associated with diff erent environmental impacts were measured and univalent,divalent and trivalent Al species were qu.n.ifi ed using HPLC/*** and organically bound Al concentrations were higher in the anthropogenically acidifi ed *** the concentrations of the leastdangerous species,the univalent,in organic soil horizons were similar for both *** concentrations of exchangeable Al forms were correlated with Ca concentrations and with pH in the organic *** known relationship of Al with soil pH was stronger in the mineral *** of exchangeable Al forms concentrations with sulphur concentrations or even more with the sulphur calcium molar ratio were found only in the JizerskéMountains,not in the novohradské.Generally,the obtained results support the hypothesis that mechanisms diff ered between natural and anthropogenic acidifi cation.

关键词： Soil acidifi cation Spruce forest Soil properties Aluminium forms Aluminium species

Photoproduction of multi-meson final states–recent results from the Crystal-Barrel/TAPS experiment at ELSA-

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2009年第12期33卷 1105-1112页

作者： u. Thoma HISKP Universitt Bonn Nussallee 14-16 53115 Bonn Germany

Multi-meson final states such as γp →pπ0π0 and γp →pπ0η have been investigated with the Crystal-Barrel/TAPS experiment at ELSA. Baryon cascades via △π and △η and also via higher mass baryon resonances are clearly observed. Based on this data and on data from other reactions a partial wave analysis has been performed from which partial decay widths of various n＊ and △＊ states into the different pπ0π0 and pπ0η decay channels have been determined, leading partly to unexpected results. In addition, polarisation observables have been investigated. The beam asymmetry X has been determined for both reactions and double polarisation data using a longitudinally polarised target and a circularly or linearly polarised photon beam has been taken. Given the angular coverage of the Crystal-Baxrel/TAPS experiment this data covers almost the full angular range and phase space. This data will provide new and important information for the partial wave analyses and bring us one step closer towards a complete experiment.

关键词： baryon spectroscopy photoproduction multi-meson final states polarisation observables

Magnetic properties of Sn-substituted ni-Zn ferrites synthesized from nano-sized powders of niO, ZnO, Fe2O3, and SnO2

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2017年第7期26卷 377-382页

作者： M A Ali M M uddin M n I Khan F u Z Chowdhury S M Hoque S I Liba Department of Physics Chittagong University of Engineering and Technology (CUET) Materials Science Division Atomic Energy Center

A series of ni0.6-x/2Zn0.4-x/2SnxFe2O4(x = 0.0, 0.05, 0.1, 0.15, 0.2, and 0.3)(nZSFO) ferrite composities have been synthesized from nano powders using a standard solid state reaction technique. The spinel cubic structure of the investigated samples has been confirmed by x-ray diffraction(XRD). The magnetic properties such as saturation magnetization(Ms),remanent magnetization(Mr), coercive field(Hc), and Bohr magneton(μ) are calculated from the hysteresis loops. The value of Msis found to decrease with increasing Sn content in the samples. This change is successfully explained by the variation of A-B interaction strength due to Sn substitution in different sites. The compositional stability and quality of the prepared ferrite composites have also been endorsed by the fairly constant initial permeability(μ’) over a wide range of frequ.n.y. The decreasing trend of μ’ with increasing Sn content has been observed. Curie temperature TChas been found to increase with the increase in Sn content. A wide spread frequ.n.y utility zone indicates that the nZSFO can be considered as a good candidate for use in broadband pulse transformers and wide band read-write heads for video recording. The composition of x = 0.05 shows unusual results and the possible reason is also mentioned with the established formalism.

关键词： magnetic properties saturation magnetization permeability Curie temperature