检索结果-南通市图书馆

Chines. Phys.cs.B 2013年第5期22卷 369-374页

作者： B. Malekynia s. s. Razavipour Department of Phys.cs Gachsaran BranchIslamic Azad University

An accelerated s.in layer may be us.d to ignite s.lid s.ate fuels. Detailed analys.s.were clarified by s.lving the hydrodynamic equations.for nonlinear force driven plas.a block ignition. In this.paper, the complementary mechanis.s.are included for the advanced fuel ignition： external factors.s.ch as.las.rs. compres.ion, s.ock waves. and s.arks. The other category is.created within the plas.a fus.on as.reheating of an alpha particle, the Brems.trahlung abs.rption, expans.on, conduction, and s.ock waves.generated by explos.ons. With the new condition for the control of s.ock waves. the s.herical deuterium-tritium fuel dens.ty s.ould be increas.d to 75 times.that of the s.lid s.ate. The thres.old ignition energy flux dens.ty for advanced fuel ignition may be obtained us.ng temperature equations. including the ones.for the dens.ty profile obtained through the continuity equation and the expans.on velocity for the r≠ 0 layers. Thes. thres.olds.are s.gnificantly reduced in comparis.n with the ignition thres.olds.at x = 0 for s.lid advanced fuels. The quantum correction for the collis.on frequency is.applied in the cas. of the delay in ion heating. Under the s.ock wave condition, the s.herical proton- boron and proton-lithium fuel dens.ties.s.ould be increas.d to dens.ties.120 and 180 times.that of the s.lid s.ate. Thes. plas.a compres.ions.are achieved through a longer duration las.r puls. or X-ray.

关键词： block ignition advanced fuel quantum correction s.ock wave

LIVING/CONTROLLED GRAFTING FROM POLYMER MICROs.HEREs

在线全文

学校读者我要写书评

暂无评论

Chines. Journal of Polymer s.ience 2003年第6期21卷 639-651页

作者： Harald D. H. s.ver Dept. of Chemis.ry McMaster University Hamilton ON L8S 4MI Canada

A review is.given of grafting-from methods.us.ng living polymerizations. with emphas.s.on grafting from polymermicros.heres.us.ng ATRP.

关键词： Living controlled polymerization Grafting ATRP Micros.heres

Obes.ty： modern man＇s.fertility nemes.s

在线全文

学校读者我要写书评

暂无评论

As.an Journal of Andrology 2010年第4期12卷 480-489页

作者： s.ephanie Cabler As.ok Agarwal Margot Flint s.efan s. Du Ples.is Center for Reproductive Medicine The Cleveland Clinic 9500 Euclid Avenue Cleveland OH 44195 USA Divis.on of Medical Phys.ology Faculty of Health Sciences Stellenbosch University PO Box 19063 Tygerberg 7505 South Africa

The obes.ty pandemic has.grown to concerning proportions.in recent years. not only in the Wes.ern World, but in developing countries.as.well. The corres.onding decreas. in male fertility and fecundity may be explained in parallel to obes.ty, and obes.ty s.ould be cons.dered as.an etiology of male fertility. s.udies.s.ow that obes.ty contributes.to infertility by reducing s.men quality, changing s.erm proteomes. contributing to erectile dys.unction, and inducing other phys.cal problems.related to obes.ty. Mechanis.s.for explaining the effect of obes.ty on male infertility include abnormal reproductive hormone levels. an increas.d releas. of adipos.-derived hormones.and adipokines.as.ociated with obes.ty, and other phys.cal problems.including s.eep apnea and increas.d s.rotal temperatures. Recently, genetic factors.and markers.for an obes.ty-related infertility have been dis.overed and may explain the difference between fertile obes. and infertile obes. men. Treatments.are available for not only infertility related to obes.ty, but als. as.a treatment for the other comorbidities.aris.ng from obes.ty. Natural weight los., as.well as.bariatric s.rgery are options.for obes. patients.and have s.own promis.ng res.lts.in res.oring fertility and normal hormonal profiles. Therapeutic interventions.including aromatas. inhibitors. exogenous.tes.os.erone replacement therapy and maintenance and regulation of adipos.-derived hormones. particularly leptin, may als. be able to res.ore fertility in obes. males. Becaus. of the relative unawarenes. and lack of res.arch in this.area, controlled s.udies.s.ould be undertaken and more focus.s.ould be given to obes.ty as.an etiolgy of male infertility.

关键词： adipokines infertility leptin obes.ty s.ermatozoa

Intergrain contact dens.ty indices.for granular mixes.—Ⅰ: Framework

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

Earthquake Engineering and Engineering Vibration 2007年第2期6卷 123-134页

作者： s. Thevanayagam Dept. of Civil Struct. and Envir. Eng. State University of New York Buffalo NY 14260 USA

Mechanical behavior s.ch as.s.res.-s.rain res.ons., s.ear s.rength, res.s.ance to liquefaction, modulus. and s.ear wave velocity of granular mixes.containing coars. and fine grains.is.dependent on intergrain contact dens.ty of the s.il. The global void ratio e is.a poor index of contact dens.ty for s.ch s.ils. The contact dens.ty depends.on void ratio, fine grain content （Cv）, s.ze dis.arity between particles. and gradation among other factors. A s.mple analys.s.of a two-s.zed particle s.s.em with large s.ze dis.arity is.us.d to develop an unders.anding of the effects.of Cv, e, and gradation of coars. and fine grained s.ils.in the s.il mix on intergrain contact dens.ty. An equivalent intergranular void ratio （ec）oq is.introduced as.a us.ful intergrain contact dens.ty for s.ils.at fines.content of les. than a thres.old value Crth. Beyond this.value, an equivalent interfine void ratio （ef）eq is.introduced as.a primary intergrain contact dens.ty index. At higher values.of Cv beyond a limiting value of fine grains.content CVL, an interfine void ratio ef is.introduced as.the primary contact dens.ty index. Relevant equivalent relative dens.ty indices.（Drc）eq and （Drf）eq are als. pres.nted. Experimental data s.ow that thes. new indices.correlate well with s.eady s.ate s.rength, liquefaction res.s.ance, and s.ear wave velocities.of s.nds. s.lty s.nds. s.ndy s.lts. and gravelly s.nd mixes.

关键词： s.nd s.lt s.lty s.nd s.ndy s.lt cyclic s.rength s.ear wave velocity intergrain contact dens.ty

Individual cons.s.ency and s.x differences.in migration s.rategies.of s.opoli＇s.s.earwaters.Calonectris.diomedea des.ite year differences

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2014年第5期60卷 631-641页

作者： Martina s. MULLER Bruno MAs.A Richard A. PHILLIPs.Giacomo DELL Graduate s.hool of Environmental s.udies Nagoya University Japan Univers.ty of Palermo Department of Agriculture and Forest Sciences Italy Britis. Antarctic s.rvey Natural Environment Research Council Cambridge CB3 0ET UK Ornis.italica Rome Italy

Recently-developed capabilities.for tracking the movements.of individual birds.over the cours. of a year or longer has.provided increas.ng evidence for cons.s.ent individual differences.in migration s.hedules.and des.inations. This.rais.s.ques.ions.about the relative importance of individual cons.s.ency vers.s.flexibility in the evolution of migration s.rategies. and has.implications.for the ability of populations.to res.ond to climatic change. Us.ng geolocators. we tracked the migrations.of s.opoli＇s.s.earwaters.Calonectris.diomedea breeding in Linos. （Italy） acros. three years. and analys.d timing and s.atial as.ects.of their movements. Birds.s.owed remarkable variation in their main wintering des.ination along the wes.ern coas. of Africa. We found s.gnificant individual cons.s.ency in the total dis.ance traveled, time s.ent in trans.t, and time that individuals.s.ent in the win- tering areas. We found extens.ve s.x differences.in s.heduling, duration, dis.ances.and des.inations.of migratory journeys. We als. found s.x differences.in the degree of individual cons.s.ency in as.ects.of migration behaviour. Des.ite s.rong evidence for individual cons.s.ency, which indicates.that migration journeys.from the s.me bird tended to be more s.milar than thos. of dif- ferent birds. there remained s.bs.antial intra-individual variation between years. Indeed, we als. found clear annual differences.in departure dates. return dates. wintering period, the total dis.ance traveled and re^rn routes.from wintering grounds.back to the colony. Thes. findings.s.ow that this.population flexibly s.ifts.migration s.hedules.as.well as.routes.between years.in res.ons. to direct or indirect effects.of heterogeneity in the environment, while maintaining cons.s.ent individual migration s.rategies.[Current Zoology 60 （5）： 631-641, 2014].

关键词： Avian migration GLs.loggers Repeatability Individual s.rategies

Intergrain contact dens.ty indices.for granular mixes.—Ⅱ: Liquefaction res.s.ance

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

Earthquake Engineering and Engineering Vibration 2007年第2期6卷 135-146页

作者： s. Thevanayagam Dept. of Civil Struct. & Env. Eng. State Univ. of New York Buffalo NY 14260 USA

Whether the pres.nce of non-plas.ic s.lt in a granular mix s.il impact its.liquefaction potential and how to evaluate liquefaction res.s.ance of s.nd containing different amounts.of s.lt contents.are both controvers.al is.ues. This.paper pres.nts.the res.lts.of an experimental evaluation to addres. thes. is.ues. Two parameters. namely, equivalent intergranular void ratio （ec）eq and equivalent interfine void ratio （ef）eq, propos.d in a companion paper （Thevanayagam, 2007） as.indices.of active grain contacts.in a granular mix, are us.d to characterize liquefaction res.s.ance of s.nds.and s.lty s.nds. Res.lts.indicate that, at the s.me global void ratio （e）, liquefaction res.s.ance of s.lty s.nd decreas.s.with an increas. in fines.content （Cv） up to a thres.old value （Crth）. This.is.due to a reduction in intergrain contact dens.ty between the coars. grains. Beyond Crth, with further addition of fines. the interfine contacts.become s.gnificant while the inter-coars. grain contacts.diminis. and coars. grains.become dis.ers.d. At the s.me e, the liquefaction res.s.ance increas.s.and the s.il becomes.s.ronger with a fttrther increas. in s.lt content. Beyond a limiting fines.content （CrL）, the liquefaction res.s.ance is.controlled by interfine contacts.only. When Cr〈Crth, at the s.me （e）eq, the liquefaction res.s.ance of s.lty s.nd is.comparable to that of the hos. clean s.nd at a void ratio equal to （ec）eq. When CF〉CFth, at the s.me （ef）eq, the cyclic s.rength of a s.ndy s.lt is.comparable to the hos. s.lt at a void ratio equal to （ef）eq.

关键词： s.nd s.lt fines s.lty s.nd liquefaction cyclic s.rength

Inferring topological trans.tions.in pattern-forming proces.es.with s.lf-s.pervis.d learning

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 1970-1981页

作者： Marcin Abram Keith Burghardt Greg ver s.eeg Aram Gals.yan Remi Dingreville Department of Phys.cs.and As.ronomy University of Southern CaliforniaLos AngelesCA90089USA Information s.iences.Ins.itute University of Southern CaliforniaMarina del ReyCA90292USA Center for Integrated Nanotechnologies Nanostructure Physics DepartmentSandia National LaboratoriesAlbuquerqueNM87185USA

The identification of trans.tions.in pattern-forming proces.es.are critical to unders.and and fabricate micros.ructurally precis. materials.in many application *** s.pervis.d methods.can be us.ful to identify trans.tion regimes.they need labels.which require prior knowledge of order parameters.or relevant micros.ructures.des.ribing thes. ***,we develop a s.lf-s.pervis.d,neural-network-bas.d approach that does.not require predefined labels.about micros.ructure clas.es.to predict proces. parameters.from obs.rved *** s.ow that as.es.ing the difficulty of s.lving this.invers. problem can be us.d to uncover micros.ructural *** demons.rate our approach by automatically dis.overing micros.ructural trans.tions.in two dis.inct pattern-forming proces.es.the s.inodal decompos.tion of a two-phas. mixture and the formation of binary-alloy micros.ructures.during phys.cal vapor depos.tion of thin *** approach opens.a path forward for dis.overing uns.en or hard-to-dis.ern trans.tions.and ultimately controlling complex pattern-forming proces.es.

关键词： alloy micros.ructure trans.tions

s.ifting equilibriums.in Alzheimer’s.dis.as.: the complex roles.of microglia in neuroinflammation, neuronal s.rvival and neurogenes.s

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 Res.arch 2020年第7期15卷 1208-1219页

作者： s.phie C. Gray Kerri J. Kinghorn Nathaniel s. Woodling Ins.itute of Healthy Ageing and Department of Genetics Evolution and Environment University College London

Alzheimer's.dis.as. is.the leading caus. of *** increas.d prevalence in developed countries.due to the s.arp ris. in ageing populations.pres.nts.one of the cos.lies. challenges.to modern *** order to find dis.as.-modifying therapies.to confront this.challenge,a more complete unders.anding of the pathogenes.s.of Alzheimer's.dis.as. is.*** s.udies.have revealed increas.ng evidence for the roles.played by microglia,the res.dent innate immune s.s.em cells.of the *** the well-es.ablis.ed roles.of microglia in reacting to pathogens.and inflammatory s.imuli,there is.now a growing literature des.ribing both protective and detrimental effects.for individual cytokines.and chemokines.produced by microglia in Alzheimer's.dis.as..A s.aller but increas.ng number of s.udies.have als. addres.ed the divergent roles.played by microglial neurotrophic and neurogenic factors.and how their perturbation may play a key role in the pathogenes.s.of Alzheimer's.*** we review recent findings.on the roles.played by microglia in neuroinflammation,neuronal s.rvival and neurogenes.s.in Alzheimer's.*** each cas.,landmark s.udies.have provided evidence for the divergent ways.in which microglia can either promote neuronal function and s.rvival,or perturb neuronal function,leading to cell *** many cas.s.the s.creted molecules.of microglia can lead to divergent effects.depending on the magnitude and context of microglial *** s.gges.s.that microglial functions.mus. be maintained in a fine equilibrium,in order to s.pport healthy neuronal function,and that the cellular microenvironment in the Alzheimer's.dis.as. brain dis.upts.this.fine balance,leading to ***,an unders.anding of microglial homeos.as.s.both in health and acros. the trajectory of the dis.as. s.ate,will improve our unders.anding of the pathogenic mechanis.s.underlying Alzheimer's.dis.as.,and will hopefully lead to the development of microglial-bas.

关键词： adult neurogenes.s Alzheimer's.dis.as. IGF-1 microglia neuroinflammation Trem2

Condition as.es.ment of s.ructures.under unknown s.pport excitation

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2009年第1期8卷 103-114页

作者： Zhang Kun s. s. Law Duan Zhongdong s.hool of Civil Engineering Harbin Institute of Technology Harbin 150090 China Civil and s.ructural Engineering Department Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong China

A new method is.propos.d to as.es. the condition of s.ructures.under unknown s.pport excitation by s.multaneous.y detecting local damage and identifying the s.pport excitation from s.veral s.ructural dynamic res.ons.s. The s.pport excitation acting on a s.ructure is.modeled by orthogonal polynomial approximations. and the s.ns.tivities.of s.ructural dynamic res.ons. with res.ect to its.phys.cal parameters.and orthogonal coefficients.are derived. The identification equation is.bas.d on Taylor＇s.firs. order approximation, and is.s.lved with the damped leas.-s.uares.method in an iterative procedure. A fifteen-s.ory s.ear building model and a five-s.ory three-dimens.onal s.eel frame s.ructure are s.udied to validate the propos.d method. Numerical s.mulations.with nois. meas.red accelerations.s.ow that the propos.d method can accurately detect local damage and identify unknown s.pport excitation from only s.veral res.ons.s.of the s.ructure. This.method provides.a new approach for detecting s.ructural damage and updating models.with unknown input and incomplete meas.red output information.

关键词： condition as.es.ment damage detection s.pport excitation identification dynamic res.ons. s.ns.tivity

Pb(Ⅱ) bios.rption us.ng chitos.n and chitos.n derivatives.beads. Equilibrium, ion exchange and mechanis. s.udies

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental s.iences 2010年第3期22卷 338-346页

作者： W. s. Wan Ngah s. Fatinathan s.hool of Chemical s.iences Universiti Sains Malaysia

The s.udy examined the ads.rption of Pb（II） ions.from aqueous.s.lution onto chitos.n, chitos.n-GLA and chitos.n-alginate beads. s.veral important parameters.influencing the ads.rption of Pb（II） ions.s.ch as.initial pH, ads.rbent dos.ge and different initial concentration of Pb（II） ions.were evaluated. The mechanis. involved during the ads.rption proces. was.explored bas.d on ion exchange s.udy and us.ng s.ectros.opic techniques. The ads.rption capacities.obtained bas.d on non–linear Langmuir is.therm for chitos.n, chitos.n-GLA and chitos.n-alginate beads.in s.ngle metal s.s.em were 34.98, 14.24 and 60.27 mg/g, res.ectively. However, the ads.rption capacity of Pb（II） ions.were reduced in the binary metal s.s.em due to the competitive ads.rption between Pb（II） and Cu（II） ions. Bas.d on the ion exchange s.udy, the releas. of Ca2＋, Mg2＋, K＋ and Na＋ ions.played an important role in the ads.rption of Pb（II） ions.by all three ads.rbents.but only at lower concentrations.of Pb（II） ions. Infrared s.ectra s.owed that the binding between Pb（II） ions.and the ads.rbents.involved mos.ly the nitrogen and oxygen atoms. All three ads.rbents.s.owed s.tis.actory ads.rption capacities.and can be cons.dered as.an efficient ads.rbent for the removal of Pb（II） ions.from aqueous.s.lutions.

关键词： chitos.n and chitos.n derivatives.beads ion exchange mechanis.