检索结果-南通市图书馆

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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 316-331页

作者： H.t.Jeong S.w.Lee w.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

the superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Corneal and intraocular pressure changes associated to the circadian rhythms:a narrative review

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第10期17卷 1921-1928页

作者： Laura barberán-Bernardos MiguelÁngel Ariza-Gracia David P Piñero Department of Optics Pharmacology and AnatomyUniversity of AlicanteSan Vicente del Raspeig 03690AlicanteSpain ARtORG Center for Biomedical Engineering Research University of BernBern 3008Switzerland Department of Ophthalmology(IMQO-Oftalmar) Vithas Medimar International HospitalAlicante 03016Spain

AIM:to synthesize the current body of research regarding the diurnal variations in intraocular pressure(IOP)and corneal biomechanical and morphological parameters,highlighting their significance in various eye ***:A comprehensive review of studies on the diurnal variations of IOP and corneal parameters was *** findings from various studies were assessed,including the Goldmann applanation tonometry(GAt)and non-contact *** on the variations in central corneal thickness(CCt),corneal curvature,and corneal biomechanics measured by the Ocular Response Analyzer system across different population groups was extracted and ***:In both healthy subjects and those with Fuchs dystrophy,IOP and CCt demonstrate marked diurnal *** remains the gold standard for tonometry,with the highest ***,its measurements are influenced by *** patients and those with pseudoexfoliation showed significant diurnal variations in *** biomechanical parameters,especially corneal hysteresis(CH)and the corneal resistance factor(CRF),largely remain stable throughout the day for most of eye conditions,with some ***,the corneal morphology diurnal variation,particularly curvature,yielded mixed conclusions across ***:Circadian rhythms significantly influence various corneal parameters,most notably IOP and *** studies should emphasize standardized approaches larger sample sizes,and delve deeper into less-explored areas,such as the effects of orthokeratology lenses on diurnal biomechanical shifts.

关键词： circadian rhythms intraocular pressure corneal thickness corneal biomechanics corneal curvature

SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 25-38页

作者： S.Parsons D.J.Hall O.Hetherington t.w.Buggey t.Arnold M.w.J.Hubbard A.Holland Centre for Electronic Imaging the Open UniversityMilton KeynesMK76AAUK

throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their *** order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance *** CCDs have been characterised,the two flight devices and the flight spa *** has been carried out at the Open University in a bespo ke cleanroom measure ment *** results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe *** at the nominal ope rating tempe rature(-120℃) it is within the procure ment ***,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science *** se rial charge transfer inefficiency degrades with temperature in full frame *** any charge losses are recovered when binning/frame transfer is implemented.

关键词： CCD soft X-ray imager characterisation SMILE

the CCD instrument background of the SMILE SXI

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 15-24页

作者： M.w.J.Hubbard O.Hetherington D.J.Hall t.w.Buggey S.Parsons t.Arnold A.Holland C.Pagani S.Sembay Centre for Electronic Imaging The Open UniversityMilton KeynesMK76AAUK X-ray and Observational Astronomy Group Department of Physics&AstronomyUniversity of LeicesterLE17RHUK

the ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation *** Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is *** shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen ***,two radiation environments can be approximated based on the shutter door position:open and *** instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two *** to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two *** results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar *** is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

关键词： instrument background X-ray astronomy space radiation

Inflow and outflow permeability tests in a very soft clay under low stresses

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： J.w.S.Vargas F.A.B.Danziger F.R.Lopes t.Lunne Federal University of Rio de Janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAt probe at SarapuíII soft clay test site are presented.A description of the BAt permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay BAt probe Inflow and outflow tests

Efficient guiding and focusing of intense laser pulse using periodic thin slits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu t.w.Huang K.Jiang C.N.wu H.Peng P.C.hen R.Li H.B.Zhuo C.t.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

栖息地条件对白杨与枫树林群落中高山天南星的丰富度和选定个体特征的影响

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 Plant Ecology 2024年第1期17卷 33-49页

作者： tomasz wójcik Kinga Kostrakiewicz-Gierałt Department of Nature Conservation and Landscape Ecology Institute of Agricultural SciencesLand Management and Environmental ProtectionUniversity of Rzeszow35-601 RzeszowPoland Department of tourism Geography and Ecology Institute of TourismFaculty of Tourism and RecreationUniversity of Physical Education in Krakow31-571 KrakowPoland

本研究于2020至2021年在西喀尔巴阡山脉的山麓地区进行,研究了高山天南星(Arum alpinum)的物种数量和选定特征的空间-时间变异。调查分别在4个永久样地中进行(Patch Ⅰ、Ⅱ、Ⅲ、Ⅳ)。Patch Ⅰ和Patch Ⅲ位于以低矮植被为主的枫树-鹅耳... 详细信息

本研究于2020至2021年在西喀尔巴阡山脉的山麓地区进行,研究了高山天南星(Arum alpinum)的物种数量和选定特征的空间-时间变异。调查分别在4个永久样地中进行(Patch Ⅰ、Ⅱ、Ⅲ、Ⅳ)。Patch Ⅰ和Patch Ⅲ位于以低矮植被为主的枫树-鹅耳枥林(tilio cordatae-Carpinetum betuli)林地中,而Patch Ⅱ和Patch Ⅳ位于以阔叶物种为主的白杨(Populetum albae)河滩林中。调查结果表明,高山天南星最丰富种群出现在Patch Ⅰ,但Patch Ⅱ和Patch Ⅳ中也存在大量的营养体和繁殖个体。个体性状的时间变异性在Patch Ⅳ最低,其次是Patch Ⅰ和Patch Ⅱ,在Patch Ⅲ最高。所有种群中均发现叶柄长度与叶片尺寸以及有性茎长度与果序特征之间的关系显著呈正相关,这一发现证实了先前的研究。这些研究结果表明,高山天南星与特定的森林群落没有密切关联。充足的遮荫和湿润富养分的土壤对该物种有利,而干燥的土壤和过多的日照可能会限制其个体的开花与结果。

关键词：高山天南星(Arum alpinum) 枫树-鹅耳枥林河滩林开花茎果序叶片山地物种

Evaluation of a hepatic biomarker of nutritional imbalance in juvenile red drum(Sciaenops ocellatus) fed 60% soybean meal-based diets using NMR-based metabolomics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第1期16卷 45-61页

作者： Fabio Casu Aaron M.watson Justin Yost t.Gibson Gaylord Daniel w.Bearden Michael R.Denson Marine Resources Research Institute South Carolina Department of Natural Resources Bozeman Fish technology Center United States Fish and Wildlife Service Marine Biochemical Sciences Group Chemical Sciences Division National Institute of Standards and Technology Hollings Marine Laboratory

A 12-week feeding trial with juvenile red drum(Sciaenops ocellatus) fed high-soybean meal(SBM) diets was conducted to investigate a putative biomarker of nutritional imbalance, N-formimino-L-glutamate(FIGLU). three fishmeal-free, 60% SBM pelleted diets(named B12, Fol, and Met, respectively) were tested to evaluate the effects on growth performance and tissue metabolite profiles of supplementation of vitamin B12(0.012 mg/kg), folate(10 mg/kg), methionine(1 g/kg) respectively, above basal supplementation levels. A fourth SBM-based diet(named B12/Fol/Met) was formulated with a combination of B12, folate, and methionine to attain the above-mentioned target concentrations. A fifth 60% SBM diet(named FwS) with methionine supplementation(1 g/kg above basal supplementation levels), enriched with taurine, lysine and threonine as well as minerals, was also tested. this diet contained formulation targets and additives which have allowed for replacing fishmeal with plant proteins in rainbow trout feeds. Control diets included a fishmeal-based diet(named FM), an unsupplemented basal 60% SBM diet(named SBM60), and a “natural” diet(named N) made up of equal parts of fish(cigar minnows), squid and shrimp as a positive reference for growth performance. Formulated feeds contained approximately 37% total crude protein, approximately 14% total crude lipid and were energetically balanced. Standard growth performance metrics were measured, and tissues(liver, muscle) were collected at week 12 to evaluate diet-induced metabolic changes using nuclear magnetic resonance(NMR)-based *** results show that the FwS diet outperformed all other SBM diets and the FM diet under all performance metrics(Pwas not detected in fish fed the N diet but was detected in those fed the SBM diets and the FM diet. Fish fed the FwS diet and the Met diet showed lower hepatic levels of FIGLU compared with the other SBM-based diets(Pting that among the different supplementatio

关键词： Aquaculture Metabolomics Nuclear magnetic resonance Red drum Soybean meal N-Formimino-L-glutamate

Generalized time-dependent generator coordinate method for induced fission dynamics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 1-12页

作者： B.Li D.Vretenar t.Nikšić J.Zhao P.w.Zhao J.Meng State Key Laboratory of Nuclear Physics and technology School of PhysicsPeking UniversityBeijing 100871China Physics Department Faculty of ScienceUniversity of Zagreb10000 ZagrebCroatia Center for Circuits and Systems Peng Cheng LaboratoryShenzhen 518055China

the generalized time-dependent generator coordinate method(tD-GCM)is extended to include pairing *** correlated GCM nuclear wave function is expressed in terms of time-dependent generator states and weight *** particle–hole channel of the effective interaction is determined by a Hamiltonian derived from an energy density functional,while pairing is treated dynamically in the standard BCS approximation with time-dependent pairing tensor and single-particle occupation *** the inclusion of pairing correlations,various time-dependent phenomena in open-shell nuclei can be described more *** model is applied to the description of saddle-to-scission dynamics of induced *** generalized tD-GCM charge yields and total kinetic energy distribution for the fission of 240Pu,are compared to those obtained using the standard time-dependent density functional theory(tD-DFt)approach,and with available data.

关键词： nuclear density functional theory generator coordinate method fission dynamics