检索结果-南通市图书馆

Journal of Materials science & Technology 2022年第27期122卷 68-76页

作者： J.christudasjustus c.s.witharamage Ganesh Walunj T.Borkar R.K.Gupta Department of Materials science and Engineering North Carolina State UniversityRaleighNC 27606United States Department of Mechanical Engineering Cleveland State UniversityClevelandOH 44115United States

Al-xV alloys(x=2 at.%,5 at.%,10 at.%)with nanocrystalline structure and high solid solubility of V were produced in powder form by high-energy ball milling(HEBM).The alloy powders were consolidated by spark plasma sintering(sPs)employing a wide range of temperatures ranging from 200 to 400°*** microstructure and solid solubility of V in Al were investigated using X-ray diffraction analysis,scanning electron microscope and transmission electron *** microstructure was influenced by the sPs temperature and V content of the *** alloys exhibited high solid solubility of V–six orders of magnitude higher than that in equilibrium state and grain sizesPs *** formation of Al3V intermetallic was detected at 400℃.Formation of a V-lean phase and bimodal grain size was observed during sPs,which increased with the increase in sPs *** hardness and elastic modulus,measured using nanoindentation,were significantly higher than commercial *** example,Al-V alloy produced by sPs at 200℃ exhibited a hardness of 5.21 GPa along with elastic modulus of 96.21 *** evolution of the microstructure and hardness with sPs temperatures has been discussed.

关键词： spark plasma sintering Aluminum alloys Nanocrystalline alloys High-energy ball milling Nanoindentation Hardness Elastic modulus

Age-hardening behavior,corrosion mechanisms,and passive film structure of nanocrystalline Al-V supersaturated solid solution

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2023年第4期135卷 1-12页

作者： J.christudasjustus M.R.Felde c.s.witharamage J.Esquivel A.A.Darwish c.Winkler R.K.Gupta Department of Materials science and Engineering North Carolina State UniversityRaleighNC 27606United States Department of chemical Biomolecular and Corrosion EngineeringThe University of AkronAkronOH 44325United States

The effect of age-hardening on microstructure,hardness,and corrosion of an Al-5at.%V alloy,produced us-ing high-energy ball milling and subsequent cold compaction,has been *** alloy exhibited a grain size below 100 nm and extremely high solid solubility of V in Al(3.1 at.%).The age-hardening was carried out at 150,200,and 250℃.The peak-aged condition of 150℃ demonstrated the highest hardness-transpired from grain refinement,precipitation,and solid solution *** corrosion re-sistance of the Al-5at.%V alloy was studied as a function of aging *** peak-aged condition retained the corrosion resistance while it deteriorated in the over-aged ***,the cor-rosion resistance of the ball-milled Al alloys in all the aging conditions was superior to that of pure *** passive film structure and origin of corrosion were studied using scanning/transmission electron mi-croscopy(s/TEM).The high corrosion resistance of the alloy was attributed to the V enrichment at the film/metal interface and deposition of V on the cathodic phases,which suppresses the dissolution of Al within the pit and therefore promotes repassivation in the early stages of corrosion.

关键词： Al alloys Nanocrystalline alloy Age-hardening Ball milling corrosion Hardness

A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

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) 2025年第1期46卷 81-100页

作者： s.sAURABH R.KIRAN D.sINGH R.VAIsH V.s.cHAUHAN school of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHsDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the c0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(HR), helicoidal exponential(HE), helicoidal semi-circular(Hs), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

关键词：

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs Víctor cilleros-Mañé Laia Just-Borràs Marta Balanyà-segura Aleksandra Polishchuk Laura Nadal Marta Tomàs carolina silvera-simón Manel M.santafé Maria A.Lanuza Unitat d’Histologia i Neurobiologia(UHNeurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and c(PKA and PKc)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PKA/PKc activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

Effect of Excited and Fourth Generation Leptons in Lepton Flavor Violating μ− → e- 2γ Decay

在线全文

学校读者我要写书评

暂无评论

chinese Physics Letters 2011年第8期28卷 51-53页

作者： s.c.İnan Department of Physics Cumhuriyet UniversitySivas 58140Turkey

We study the lepton flavor violatingμ−→e-2γdecay induced by the mediation of heavy leptons,such as the excited and fourth generation *** of these leptons inμ−→e-2γdecay are *** is found that the branching ratio of this decay is very sensitive to excited and fourth generation ***,we obtain the bounds on model parameters by using the current experimental limit of this decay.

关键词： decay excited branching

Direct Graviton Production via Photon-Photon Fusion at the cERN-LHc

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 Letters 2012年第3期29卷 63-66页

作者： s.c.İnan Department of Physics Cumhuriyet University58140SivasTurkey

The potential of pp→pγγp/→pGp process in scenarios of the Arkani-Hamed,Dimopoulos,Dvali(ADD)and Randall-sundrum(Rs)model at the LHc is examined,and 95%*** on the model parameters are *** is found that the sensitiv... 详细信息

关键词： reaction bounds LHc

controversies in fecal incontinence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2025年第3期31卷 113-119页

作者： Andreia Albuquerque satish s c Rao school of Medicine and Biomedical sciences Fernando Pessoa UniversityGondomar 4420-096PortoPortugal Precancerous Lesions and Early cancer Management Research Group RIsE@cI-IPO(Health Research Network) Portuguese Oncology Institute of PortoPorto 4200-072Portugal Division of Gastroenterology and Hepatology Department of Internal MedicineAugusta UniversityAugustaGA 30912United States

Fecal incontinence is a common condition that can significantly impact patients’quality of *** anal sphincter injury and anorectal surgeries are common *** ultrasound and anorectal manometry are important diagnostic tools for evaluating *** are various treatment options,including diet,lifestyle modifications,drugs,biofeedback therapy,tibial and sacral nerve neuromodulation therapy,and *** this editorial,we will discuss current controversies and novel approaches to fecal *** for asymptomatic anal sphincter defects after obstetric anal sphincter injury and in patients with inflammatory bowel disease is not generally recommended,but may be helpful in selected *** Garg incontinence score is a new score that includes the assessment of solid,liquid,flatus,mucous,stress and urge fecal *** tests such as translumbosacral anorectal magnetic stimulation and novel therapies such as translumbosacral neuromodulation therapy are promising diagnostic and treatment options,for both fecal incontinence and *** biofeedback therapy can overcome some limitations of the office-based *** muscle-derived cell implantation of the external anal sphincter has been further studied as a possible treatment *** neuromodulation may be useful in scleroderma,congenital fecal incontinence and inflammatory bowel disease but merits further study.

关键词： Fecal incontinence Endoanal ultrasound Anal sphincter defects Biofeedback Neuropathy sacral neuromodulation

Reduction of wave impact on seashore as well as seawall by floating structure and bottom topography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2020年第6期32卷 1191-1206页

作者： Amandeep Kaur s.c.Martha Department of Mathematics Indian Institute of Technology RoparRupnagarPunjabIndia

The three-dimensional problem involving diffraction of water wave by a finite floating rigid dock over an arbitrary bottom is studied for two cases(1)in the absence of wall(2)in the presence of *** problem is handled for its solution with the aid of step *** both asymmetric and symmetric arbitrary bottom profile is approximated using successive *** approximation helps to apply the matched eigenfunction expansion method,in result,system of algebraic equations are obtained which are solved to determine the hydrodynamic quantities,namely,force experienced by rigid floating dock as well as rigid seawall,free surface elevation,transmission and reflection coefficients associated with transmission and reflected waves *** effects of various structural and system parameters are examined on these hydrodynamics *** appropriate values of length and thickness of dock,water depth and angle of incidence provide the salient information to marine and coastal engineers to design the offshore structures and creation of parabolic trench on the *** present results are compared with known results in special case of bottom *** energy balance relation is derived and checked.

关键词： Arbitrary bottom step approximation hydrodynamic quantities

An Inverse Approach for Extracting Elastic-plastic Properties of Thin Films from small scale sharp Indentation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2012年第7期28卷 626-635页

作者： Z.s. Ma Y.c. Zhou s.G. Long c.s. Lu Key Laboratory of Low Dimensional Materials ~ Application Technology of Ministry of Education Xiangtan Uni-versity Xiangtan 411105 China Faculty of Materials Optoelectronics and Physics Xiangtan University Xiangtan 411105 China Department of Mechanical Engineering Curtin University of Technology Perth WA 6845 Australia

An inverse method for extracting the elastic-plastic properties of metallic thin films from instrumented sharp indentation has been proposed in terms of dimensional analysis and finite element modeling. A wide range of materials with different elastic modulus, yield strength, and strain-hardening exponent were *** to the Nix-Gao model for the depth dependence of hardness H,the relationship between elastic modulus E and indentation depth h can be expressed as By combiningthese two formulas, we find that there is a relationship between yield stress and indentation depth h：where σyO is the yield strength associated with the strain-hardening exponent n, the true hardness Ho and the true elastic modulus *** constant, whichis only related to n, and hH and hE are characteristic lengths for hardness and elastic modulus. The results obtained from inverse analysis show that the elastic-plastic properties of thin films can be uniquely extracted from the solution of this relationship when the indentation size effect has to be taken into account.

关键词： Indentation Elastic-plastic properties Metal thin films Inverse analysis

Urban china in Transformation:Hybrid Economy,Juxtaposed space,and New Testing Ground for Geographical Enquiries

在线全文

学校读者我要写书评

暂无评论

chinese Geographical science 2011年第1期21卷 1-16页

作者： George c s LIN Department of Geography University of Hong Kong

History has brought us into a significant moment when the majority of the human kind has taken up resi-dence in urban settlements. The focus of global urbanization has shifted to the developing world and the center of manufacturing is no longer confined to the Global North. This paper provides a periodical assessment of the current status of china's urban transformation in the global context of a shifting emphasis of industrialization and urbaniza-tion. china's phenomenal urban transformation deserves a special attention not only because of its unparalleled scale and speed but also because of its distinct trajectory of growth that does not conform to normal theoretical ex-pectations. The results of assessment revealed an urban economy with remarkable hybridity, a society that is in-creasingly stratified, polarized, and segregated, and a juxtaposed urban space undergoing restless and pervasive transformation. A decentering world should entail a decentering knowledge production. A critical reflection upon the chinese patterns and processes of urban transformation has identified 4 main issues with great potentials for inno-vative knowledge production, namely: 1) privatization and economic development; 2) state, society, and space; 3) urbanization of capital, labor, and land; and 4) the environment and chinese political ecology. The paper closes with the remark that a rapidly transforming urban china has presented itself as a fertile and resourceful testing ground for critical and innovative geographic enquiries.

关键词： urban geography urbanization chinese cities political economy china