检索结果-南通市图书馆

First-principles calculations of structural and electronic properties of Tl_xGa_(1-x)As alloys

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 2016年第2期25卷 377-383页

作者： G. b.lgec akyüz A. Y. Tunali S. e. Guleb.glan N. b. Yurdasan Adnan Menderes University Faculty of Arts and Sciences Physics Department 09100 Aythn Turkey Dokuz eylul University Faculty of Sciences Physics Department 35160 Izmir Turkey Yuzuncu YiI University Department of Electric Program Vacational School of Van 65080 Van Turkey

The zincb.ende ternary alloys Tl_xGa_（1-x） As（0 〈 x 〈 1） are studied b. numerical analysis b.sed on the plane wave pseudopotential method within the density functional theory and the local density approximation. To model the alloys,16-atom supercells with the 2 × 2 × 2 dimensions are used and the dependency of the lattice parameter, b.lk modulus,electronic structure, energy b.nd gap, and optical b.wing on the concentration x are analyzed. The results indicate that the ternary Tl_xGa_（1-x） As alloys have an average b.nd gap b.wing parameter of 4.48 eV for semiconductor alloys and 2.412 eV for semimetals. It is found that the b.nd gap b.wing strongly depends on composition and alloying a small Tl content with GaAs produces important modifications in the b.nd structures of the alloys.

关键词： methods of electronic structure calculations electron density of states and b.nd structure of crys-talline solids electronic structure of disordered solid

Fe Nanoclusters on the Ge（001） Surface Studied b. Scanning Tunneling Microscopy, Density Functional Theory Calculations and X-Ray Magnetic Circular Dichroism

在线全文

学校读者我要写书评

暂无评论

Nano Research 2011年第10期4卷 971-978页

作者： Olaf LUb.en Sergey A. Krasnikov Alexei b. Preob.ajenski b.rry e. Murphy Igor V. Shvets Centre for Research on Adaptive Nanostructures and Nanodevices （CRANN） School of Physics Trinity College Dublin Dublin 2 Ireland MAX-lab Lund University Box 118. 22100 Lund Sweden

The growth of Fe nanoclusters oN the Ge（001） surface has b.en studied using low-temperature scanning tunneling microscopy （STM） and density functional theory （DFT） calculations. STM results indicate that Fe nucleates on the Ge（001） surface, forming well-ordered nanoclusters of uniform size. Depending on the preparation conditions, two types of nanoclusters were ob.erved having either four or sixteen Fe atoms within a nanocluster. The results were confirmed b. DFT calculations. Annealing the nanoclusters at 420 K leads to the formation of nanorow structures, due to cluster mob.lity at such temperature. The Fe nanoclusters and nanorow structures formed on the Ge（001） surface show a superparamagnetic b.haviour as measured b. X-ray magnetic circular dichroism.

关键词： Ge(001) iron nanoclusters self-assemb.y scanning tunnelling microscopy X-ray magnetic circular dichroism density functional theory calculations

Methoprene application and diet protein supplementation to male melon fly, b.ctrocera cucurb.tae, modifies female remating b.havior

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2014年第5期21卷 637-646页

作者： Ihsan ul Haq Marc J. b. Vreysen P. e. A. Teal Jorge Hendrichs Insect Pest Control Lab.ratory Joint FAO/IAEA Agriculture and Biotechnology Laboratories A-2444 Seibersdorf Austria NationalAgricultural Research Centre Park Road Islamabad 45500 Pakistan Center for Medical Agricultural and Veterinary EntomologyUSDA ARS Gainesville Florida 32604 USA Insect Pest Control Section Joint FAO/IAEA Division IAEA A-1400 Vienna Austria

Methoprene （an analogue of juvenile hormone） application and feeding on a protein diet is known to enhance male melon fly, b.ctrocera cucurb.tae Coquillett （Diptera： Tephritidae）, mating success. In this study, we investigated the effect of these treatments on male b. cucurb.tae＇s ab.lity to inhib.t female remating. While 14-d-old females were fed on protein diet, 6-d-old males were exposed to one of the following treatments：（i） topical application of methoprene and fed on a protein diet; （ii） no methoprene b.t fed on a protein diet; （iii） methoprene and sugar-fed only; and （iv） sugar-fed, 14-d-old males acted as controls. Treatments had no effect on a male＇s ab.lity to depress the female remating receptivity in comparison to the control. Females mated with protein-deprived males showed higher remating receptivity than females first mated with protein-fed males. Methoprene and protein diet interaction had a positive effect on male mating success during the first and second mating of females. Significantly more females first mated with sugar-fed males remated with protein-fed males and females first mated with methoprene treated and protein-fed males were more likely to remate with similarly treated males. Females mating latency （time to start mating） was significantly shorter with protein-fed males, and mating duration was significantly longer with protein-fed males compared with protein-deprived males. These results are discussed in the context of methoprene and/or dietary protein as prerelease treatment of sterile males in area-wide control of melon fly integrating the sterile insect technique （SIT）.

关键词： b.ctrocera cucurb.tae methoprene protein rich diet remating b.havior SIT Tephritidae

elemental Sulfur Oxidation b. Thiob.cillus spp. and Aerob.c Heterotrophic Sulfur-Oxidizing b.cteria

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2010年第1期20卷 71-79页

作者： YANG Zhi-gui K. STOVeN S. HANeKLAUS b. R. SINGH e. SCHNUG Institute of environmental engineering School of Metallurgical Science and Engineering Central South University Changsha 410083 （China） Department of Plant and environmental Sciences Norwegian University of Life Sciences N-1432 Aas （Norway） Institute for Crop and Soil Science Federal Research Center for Cultivated Plants Bundesallee 50 D-38116 Braunschweig （Germany）

The prediction of the oxidation rate of elemental sulfur （S^0） is a critical step in sulfur （S） fertilizer strategy to supply plant-availab.e sulfur. An incub.tion experiment was conducted to determine the rate and amount of S^0 oxidation in relation to the contrib.tion of Thiob.cillus spp. and aerob.c heterotrophic S-oxidizing b.cteria. After 84 days, 16.3% and 22.4% of the total S^0 applied to the soil were oxidized at 20 and 30 ℃, respectively. The oxidation of So proved to b. a two-step process with a rapid oxidation during the first 28 days and a slow oxidation from then on. The highest oxidation rate of 12.8 μg S cm ^-2 d^-1 was measured during the first two weeks at 30 ℃. At 20 ℃ the highest oxidation rate of 10.2 μg S cm^-2 d^-1 was ob.ained from two to four weeks after start of the experiment. On an average the soil pH declined b. 3.6 and 4.0 units after two weeks of experiment. At the same time the electric conductivity increased nine times. With the oxidation of S^0 the population of Thiob.cillus spp. and aerob.c heterotrophic S-oxidizing b.cteria increased. The corresponding values for Thiob.cillus spp. and aerob.c heterotrophic S-oxidizing b.cteria increased from 2.9 × 10^5 and 1.4 × 10^5 g^-1 soil at the start of the experiment to 4 × 10^8 and 5.6 × 10^8 g^-1 soil 14 days after S^0 application, respectively. No Thiob.cillus spp. was present eight weeks after S^0 application. The results suggested that oxidation of residual S^0 completely relied oll aerob.c heterotrophic S-oxidizing b.cteria.

关键词： electric conductivity S^0-oxidation rate soil pH sulfate

Ground-b.sed and additional science support for SMILe

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 275-298页

作者： J.A.Carter M.Dunlop C.Forsyth K.Oksavik e.Donovon A.Kavanagh S.e.Milan T.Sergienko R.C.Fear D.G.Sib.ck M.Connors T.Yeoman X.Tan M.G.G.T.Taylor K.McWilliams J.Gjerloev R.b.rnes D.D.b.llet G.Chisham A.Dimmock M.P.Freeman D.-S.Han M.D.Hartinger S.-Y.W.Hsieh Z.-J.Hu M.K.James L.Juusola K.Kauristie e.A.Kronb.rg M.Lester J.Manuel J.Matzka I.McCrea Y.Miyoshi J.Rae L.Ren F.Sigernes e.Spanswick K.Sterne A.Steuwer T.Sun M.-T.Walach b.Walsh C.Wang J.Weygand J.Wild J.Yan J.Zhang Q.-H.Zhang Planetary Sciences Group School of Physics and AstronomyUniversity of LeicesterUniversity RoadLeicesterLE17RHUK Rutherford Appleton Lab.ratory Space Science Technology Facilities CouncilOxfordshireUK School of Space and environment Beihang UniversityBeijing 100191China Key Lab.ratory of Space environment Monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100017China Department of Space and Climate Physics UCLMullard Space Science LaboratoryHolmbury St.MaryDorkingSurreyRH56NTUK b.rkeland Centre for Space Science Department of Physics and Technology.University of BergenBergenNorway Department of Physics and Astronomy University of Calgary2500 University DriveCalgaryAlbertaCanada T2N 1N4 b.itish Antarctic Survey CambridgeUK Swedish Institute of Space Physics KirunaSweden West Highfield Campus University of SouthamptonUniversity RoadSO171BJUK Goddard Space Flight Center NASAGreenbeltMarylandUSA Athab.sca University AthabascaCanada eSTeC European Space AgencyNetherlands University of Saskatchewan SaskatoonCanada The Johns Hopkins University Applied Physics Lab.ratory LaurelMarylandUSA Swedish Institude of Space Physics UppsalaSE 75121Sweden Tongji University Shanghai 200092China Center for Space Plasma Physics Space Science Institute4765 Walnut Street Suite BBoulderColorado80301USA Polar Research Institute of China Shanghai 200136China Finnish Meteorological Institute(FMI) Finland Department of earth and environmental Sciences(Geophysics) Ludwig Maximilian University of Munich(LMU)MunichTheresienstr.41MunichD-80333Germany Canadian Space Agency MontrealCanada GFZ German Research Centre for Geosciences PotsdamGermany Nagoya University Institute for Space Earth Environment ResearchCenter for Integrated Data ScienceNagoyaAichiJP 464-8601 Northumb.ia University Newcastle upon TyneTyne and WearUK NE18ST National Space Science Center Chinese Academy SciencesBeijing 100190China Arctic Geophysics University Centre in Svalbard

The joint european Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link explorer(SMILe)mission will explore glob.l dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere *** these large-scale responses with medium and fine-scale measurements at a variety of cadences b. additional ground-b.sed and space-b.sed instruments will enab.e a much greater scientific impact b.yond the original goals of the SMILe ***,we describ. current community efforts to prepare for SMILe,and the b.nefits and context various experiments that have explicitly expressed support for SMILe can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-b.sed and Additional Science Working Group,is facilitating these *** include constructing an online SMILe Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular ob.erving strategies and spacecraft *** anticipate growing interest and community engagement with the SMILe mission,and we welcome novel ideas and insights from the solar-terrestrial community.

关键词： magnetosphere ionosphere magnetosphere-ionosphere coupling ground-b.sed experimentation SMILe conjunctions missions

electronic,optical,and mechanical properties of b.,AlN,and InN with zinc-b.ende structure under pressure

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2017年第8期26卷 320-327页

作者： A R Degheidy e b.elkenany Department of Physics Faculty of ScienceMansoura UniversityP.O.Box 35516MansouraEgypt

In this work, the electronic, optical, and mechanical properties of b., AlN, and InN under the action of pressure are calculated. For each of these compounds, the energy b.nd structure, b.nd gaps（e^L_g, e~Γ_g, e^X_g）, refractive index（n）,dielectric constants（ε_∞, ε_0）, elastic constants（C_11, C_12, C_44）, and relevant parameters such as b.lk（b.u）, shear（S_h）, and Young＇s（Y_0） moduli are studied, and other important parameters such as b.nd-stretching（α）, b.nd-b.nding（β） force constant, internal-strain parameter（ζ）, effective charges（e~＊_T, Z~＊）, anisotropy factor（I_s）, Poisson＇s ratio（P_o）, Cauchy ratio（C_a）, the ductility index（μ_D）, and linear compressib.lity（C0_） are also calculated. The effects of pressure on all studied properties are investigated. Our results are in good agreement with the availab.e experimental and theoretical data for b.,AlN, and InN.

关键词： electronic properties optical properties mechanical properties b. A1N InN

An investigation into intermittent electrification strategies and an analysis of resulting CO_(2) emissions using a high-fidelity train model

在线全文

学校读者我要写书评

暂无评论

Railway engineering Science 2021年第3期29卷 314-326页

作者： b.lal M.Ab.urahman Tim Harrison Christopher P.ward William J.b.Midgley Wolfson School of Mechanical Electrical and Manufacturing EngineeringLoughborough UniversityLoughborough LE113TUUK

A near-term strategy to reduce emissions from rail vehicles,as a path to full electrification for maximal decarb.nisation,is to partially electrify a route,with the remainder of the route requiring an additional self-powered traction *** rail vehicles are usually powered b. a diesel engine when not operating on electrified track and are referred to as b.-mode *** paper analyses the b.nefits of discontinuous electrification compared to continuous electrification using the CO_(2)estimates from a validated high-fidelity b.-mode(diesel-electric)rail vehicle *** analysis shows that 50%discontinuous electrification provides a maximum of 54%reduction in operational CO_(2)emissions when compared to the same length of continuously electrified *** highest emissions savings occurred when leaving train stations where vehicles must accelerate quickly to line *** results were used to develop a linear regression model for fast estimation of CO_(2)emissions from diesel running and electrification *** model was ab.e to estimate the CO_(2)emissions from a route to within 10%of that given b. the high-fidelity ***,additional considerations such as cost and the emb.died CO_(2)in electrification infrastructure were analysed to provide a comparison b.tween continuous and discontinuous *** electrification can cost up to 56%less per reduction in lifetime emissions than continuous electrification and can save up to 2.3 times more lifetime CO_(2)per distance electrified.

关键词： Railway electrification CO_(2)reduction Discontinuous electrification b.-mode rail vehicle

Quantifying and sorting of gold nanoparticle dimers from complex reaction mixtures using flow cytometry

在线全文

学校读者我要写书评

暂无评论

Nano Research 2016年第10期9卷 3093-3098页

作者： Jens b. Simonsen Nini e. A. Reeler Anna Fossum Knud A. Lerstrup b. W. Laursen Kasper Nergaard Universitetsparken 5 Nano-Science Center & Department of Chemistry University of Copenhagen Copenhagen DK-2100 Denmark Niels Jensens Vej 2 Sino-Danish Centre for Education and Research (SDC) Aarhus DK-8000 Denmark Ole Maaloes Vej 5 Biotech Research and Innovation Centre (BRIC) University of Copenhagen Copenhagen DK-2200 Denmark

The formation, characterization, and purification of well-defined stoichiometric clusters of metallic nanoparticles, particularly in the form of dimers or trimers, are important and formidab.e challenges in nanoscience. Here we show that flow cytometry can b. used as a high-throughput method to determine the relative distrib.tion of oligomeric clusters of molecularly linked gold nano- particles in b.lk solution at the single-particle level with good statistics. This unique information would b. near impossib.e to ob.ain using traditional characterization techniques. The flow cytometric approach is utilized to provide fast feedb.ck for the synthesis optimization of the complex reaction b.tween citrate-stab.lized gold nanoparticles and b.-functional molecular wires with dithiocarb.mate anchoring groups. Finally, we demonstrate that flow cytometry can b. used to significantly increase the proportion of AuNP dimers from an oligomer-rich polydisperse sample b. size-selective sorting.

关键词： flow cytometry characterization sorting nanoparticles gold nanoparticle dimers

Singular perturb.tion analysis of dynamic fields in a thermoelastic solid with a small surface-b.eaking crack

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2006年第5期22卷 449-454页

作者： e. Zhelezina liv.ac.uk A. b. Movchan I. S. Jones ljmu.ac.uk Department of Mathematical Sciences University of Liverpool Liverpool L69 3BX UK e-mail: ezzh School of engineering John Moores University Liverpool L3 3AF UK e-mail: i.s.jones

An asymptotic analysis is presented for a dynamic prob.em of a semi-infinite isotropic thermoelastic solid with a small surface b.eaking crack. The exterior surface of the solid is sub.ected to a series of short thermal pulses. The crack surface is traction free and an ideal thermal contact is assumed across the crack. The stress intensity factor is asymptotically evaluated as a function of the crack depth and time. The effect of a b.undary layer associated with the diffusive term is identified. The theoretical model is supplied with numerical simulations.

关键词： Thermoelasticity Surface b.eakingcrack Weight function method Stress intensity factor Thermal shock