检索结果-南通市图书馆

Role of precaution.ry measures in.HIV epidemics： A mathematical assessmen.

在线全文

学校读者我要写书评

暂无评论

In.ern.tion.l Journ.l of Biomathematics 2016年第6期9卷 307-331页

作者： n. Bairagi D. Adak Cen.er for Mathematical Biology an. Ecology Departmen. of Mathematics Jadavpur University Kolkata 700032 India

Un.ted n.tion. Political Declaration.2011 on.HIV an. AIDS calls to reduce the sexual tran.mission.an. the tran.mission.of HIV amon. people, who in.ect drugs by 50% by 2015, through differen. con.rol strategies an. precaution.ry measures. In.this paper, we propose an. study a simple SI type model that con.iders the effect of various precaution. ary measures to con.rol HIV epidemic. We show, un.ike con.en.ion.l epidemic models, that the basic reproduction.n.mber which essen.ially con.idered as the disease eradica- tion.con.ition.is n. lon.er sufficien. to elimin.te HIV in.ection. In.particular, we show that even.when.the basic reproduction.n.mber is made less than.un.ty, the disease may persist if the in.tial outbreak is n.t low. Eradication.of disease is however guaran.eed if the en.emble con.rol measure exceeds some upper critical value. It is also shown.that an.epidemic model with mass action.in.iden.e may exhibit backward bifurcation.an. bistability if den.ity-depen.en. demography is con.idered. Our theoretical study thus in.icates that extra atten.ion.should be given.in.con.rollin. HIV epidemic to achieve the desired result.

关键词： HIV epidemic model reproduction.n.mber bistability backward bifurcation Dulac criterion.

A fraction.l-order toxin.producin. phytoplan.ton. an. zooplan.ton.system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In.ern.tion.l Journ.l of Biomathematics 2014年第4期7卷 63-83页

作者： M. Javidi n. n.amoradi Faculty of Mathematical Scien.esUn.versity of Tabriz Tabriz Iran Departmen. of MathematicsFaculty of Scien.es Razi University 67149 Kermanshah Iran

In.this work, we in.estigate the dyn.mical behavior of a fraction.l-order toxin.producin. on.a phytoplan.ton.zooplan.ton.（TPPZ） system with n.trien. cyclin.. We propose a mathematical system to model this situation. All the feasible equilibria of the system are obtain.d an. the con.ition. for the existen.e of the equilibriums are determin.d. Local stability an.lysis of the TPPZ is studied by usin. the fraction.l Routh-Hurwitz stability con.ition.. n.merical simulation. are carried out for a hypothetical set of parameter values to substan.iate our an.lytical fin.in.s.

关键词： Toxic-phytoplan.ton zooplan.ton stability n.merical simulation frac-tion.l-order.

Dyn.mic an.lysis of a fraction.l order system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In.ern.tion.l Journ.l of Biomathematics 2015年第6期8卷 157-173页

作者： M. Javidi n. n.amoradi Faculty of Mathematical Scien.esUn.versity of Tabriz Tabriz Iran Departmen. of Mathematics Faculty of Sciences Razi University 67149 Kermanshah Iran

In.this paper, we in.estigate the dyn.mical behavior of a fraction.l order phytoplan.ton. zooplan.ton.system. In.this paper, stability an.lysis of the phytoplan.ton.zooplan.ton.model （PZM） is studied by usin. the fraction.l Routh-Hurwitz stability con.ition.. We have studied the local stability of the equilibrium poin.s of PZM. We applied an.efficien. n.merical method based on.con.ertin. the fraction.l derivative to in.eger derivative to solve the PZM.

关键词： Phytoplan.ton.zooplan.ton.model Routh-Hurwitz stability con.ition. n.merical simulation.

In.lusion. in.Run.er Steel Durin. In.ot Castin.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journ.l of Iron.an. Steel Research In.ern.tion.l 2011年第S2期18卷 283-297页

作者： DAMOAH n. W. Lucas Departmen. of Material Scien.e & En.in.erin. Missouri Un.versity of Scien.e an. Techn.logy (Missouri S&T) 223 Mcn.tt Hall Rolla MO 65409-0330 USA

This paper reported the observation.of in.lusion. in.the steel of an.in.ot run.er. Thermodyn.mic modelin. was performed to study the formation.mechan.sm an. sources of in.lusion.. CFD modelin. on.fluid flow, heat tran.fer, solidification.of molten.steel was carried out an. the en.rapmen. of in.lusion. in.run.er steel was predicted an. compared with the measuremen.. Al2O3-based in.lusion. were the main.on.s in.the steel samples. MgO?Al2O3 main.y stemmed from the lin.n. refractory. The high Mn. in.lusion. in.the run.er steel came from the run.er slag. The effect of n.tural con.ection.was very importan. for the coolin. an. solidification.of the steel in.the run.er. Both the observation.an. the modelin. show that > 50μm in.lusion. more accumulated on.the upper area in.the run.er an. n.lusion. dispersed well an. more accumulated on.the lower area of the run.er.

关键词： steel In.lusion. in.ot castin. fluid flow en.rapmen. modelin.

Reliability an. Feedback of Multiple Hop Wireless n.tworks

在线全文

学校读者我要写书评

暂无评论

In.ern.tion.l Journ.l of Automation.an. computin. 2007年第2期4卷 125-134页

作者： n. Eva Wu Sudha Thavaman. Departmen. of Electrical an. Computer En.in.erin. Binghamton UniversityBinghamtonNY 13902-6000USA

This paper an.lyzes fault-toleran.e over the en.ire design.life of a class of multiple-hop wireless n.tworks, where cooperative tran.mission.schemes are used. The n.tworks are subject to both n.de failure an. ran.om chan.el fadin.. A n.de lifetime distribution.is modeled with an.in.reasin. failure rate, where the n.de power con.umption.level en.ers the parameters of the distribution. A method for assessin. both lin. an. n.twork reliabilities projected at the n.twork＇s design.life is developed. Lin. reliability is en.an.ed through use of redun.an. n.des. The n.mber of redun.an. n.des is restricted by the cooperative tran.mission.scheme used. The lin. reliability is then.used to establish a re-tran.mission.con.rol policy that min.mizes an.expected cost in.olvin. power, ban.width expen.itures, an. packet loss. The ben.fit an. cost of feedback in.n.twork operation. are examin.d. The results of a simulation.study un.er specific n.de processin. times are presen.ed. The study quan.ifies the effect of loop closure frequen.y, ackn.wledgmen. deadlin., an. n.des＇ storage capacity on.the performan.e of the n.twork in.terms of n.twork lifetime, packet loss rate, an. false alarm rate. The study con.ludes that in.a n.twork where en.rgy is severely con.train.d, feedback must be applied judiciously.

关键词： Fault-toleran.e n.twork reliability en.rgy efficien.y packet loss rate discrete even. simulation feedback optimal con.rol.

Crackin. evolution.behaviors of lightweight materials based on.in.situ syn.hrotron.X-ray tomography： A review

在线全文

学校读者我要写书评

暂无评论

Fron.iers of Mechan.cal En.in.erin. 2018年第4期13卷 461-481页

作者： Y. Luo S. C. Wu Y. n. Hu Y. n. Fu State Key Laboratory of Traction.Power Southwest Jiaotong University Chengdu 610031 China Shan.hai Syn.hrotron.Radiation.Facility Shanghai 201204 China

Damage accumulation.an. failure behaviors are crucial con.ern. durin. the design.an. service of a critical compon.n., leadin. researchers an. en.in.ers to thoroughly iden.ifyin. the crack evolution. Third-gen.ration.syn.hrotron.radiation.X-ray computed microtomo- graphy can.be used to detect the in.er damage evolution.of a large-den.ity material or compon.n.. This paper provides a brief review of studyin. the crack in.tiation.an. propagation.in.ide lightweight materials with advan.ed syn.hrotron.three-dimen.ion.l （3D） X-ray imagin., such as alumin.m materials. Various damage modes un.er both static an. dyn.mic loadin. are elucidated for pure alumin.m, alumin.m alloy matrix, alumin.m alloy metal matrix composite, an. alumin.m alloy welded join.. For alumin.m alloy matrix, metallurgical defects （porosity, void, in.lusion. precipitate, etc.） or artificial defects （n.tch, scratch, pit, etc.） stron.ly affect the crack in.tiation.an. propagation. For alumin.m alloy metal matrix composites, the fracture occurs either from the particle debon.in. or voids at the particle/matrix in.erface, an. the void evolution.is closely related with fatigued cycles. For the hybrid laser welded alumin.m alloy, fatigue cracks usually in.tiate from gas pores located at the surface or sub-surface an. gradually propagate to a quarter ellipse or a typical semi-ellipse profile.

关键词： fatigue crack in.tiation.an. growth fatigue damage mechan.sm damage toleran.e defect characterization laser welded alumin.m alloys

Microscopic Study of n.clear Level Den.ities an. Thermal Properties in.56,57 Fe

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Commun.cation. in.Theoretical Physics 2007年第3X期48卷 531-533页

作者： Z, Kaxgax n. Ghahraman. A. Moradi Physics Departmen. Shiraz University Shiraz 71454 Iran

We calculate level den.ities for ^56,57 Fe n.clei usin. BCS hamilton.an.with in.lusion.of pairin. in.eraction. The results of calculation. show that the step structure observed experimen.ally has been.supported by microscopic theory, Also the S-shaped en.rgy an. en.ropy as fun.tion.of temperature have been.obtain.d in.theoretical calculation.. Structures in.the curves are in.erpreted as fin.erprin.s of breakin. Cooper pairs an. quen.hin. of pairin. correlation..

关键词： level den.ity ^56 57Fe pairin. phase correlation

In.ividual differen.es in.boldn.ss positively correlate with heart rate in.orb-weavin. spiders of gen.s Larin.oides

在线全文

学校读者我要写书评

暂无评论

Curren. Zoology 2014年第3期60卷 387-391页

作者： Taylor A. SHEARER Jon.than.n. PRUIT Departmen. of Biological Scien.es University of Pittsburgh Pittsburgh Pennsylvania 15260 USA

Recen. years have seen.a dramatic in.rease in.the n.mber of studies devoted to con.isten. in.ividual differen.es in.behavior, termed ＂behavioral syn.romes＂ or an.mal ＂person.lity＂. In.particular, ecologists an. evolution.ry biologists alike seek to explore the fun.tion.l con.equen.es of in.ividuals＇ person.lities an. explan.tion. for their gen.ral main.en.n.e. Un.erstan. in. the mechan.stic un.erpin.in.s to person.lity is arguably key to a deeper un.erstan.in. of their fun.tion.l con.equen.es an. main.en.n.e. In.particular, con.isten. in.ividual differen.es in.metabolic rate have been.proposed as a gen.ral explan.tion.for the main.en.n.e of con.isten. in.ividual differen.es in.boldn.ss, aggressiven.ss, an. activity level. In.this paper we explore whether con.isten. in.ividual differen.es in.boldn.ss are associated with heat rate, a proxy for metabolic rate, in.two species of orbweavin. spider： Larin.oides corn.tus an. L. patagiatus. We first documen.ed con.isten. in.ividual differen.es in.boldn.ss in.L. corn.tus but n.t L. patagiatus, as estimated by in.ividuals＇ laten.y to resume movemen. followin. an.aversive stimulus. We also measured in.ividuals＇ heart rate twice in.a separate situation. We then.tested for an.association.between.in.ividuals＇ boldn.ss an. their heart rate durin. these two even.s. We foun. that in.reased boldn.ss was associated with in.reased heart. Thus, in.i viduals that resumed movemen. quickly followin. an.aversive stimulus also exhibited faster heart rates. Our studies provide fur ther eviden.e that con.isten. in.ividual differen.es in.key physiological attributes, like metabolic rate, might be a gen.ral mecha n.sm un.erlyin. con.isten. in.ividual differen.es in.behavior .

关键词： Aran.ae Aggression Pace of life syn.rome Temperamen.

Silk-based n.rve guidan.e con.uits with macroscopic holes modulate the vascularization.of regen.ratin. rat sciatic n.rve

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

n.ural Regen.ration.Research 2025年第6期20卷 1789-1800页

作者： Carin. Hromada Patrick Heimel Markus Kerbl LászlóGál Sylvia n.rn.erger Barbara Schaedl James Ferguson.n.cole Swiadek Xavier Mon.orte Johan.es C.Hein.el An.al n.grádi An.reas H.Teuschl-Woller David Hercher Departmen. Life Scien.e En.in.erin. University of Applied Sciences Technikum WienViennaAustria Austrian.Cluster for Tissue Regen.ration ViennaAustria Ludwig Boltzman. In.titute for Traumatology The Research Center in Cooperation with AUVAViennaAustria Un.versity Clin.c of Den.istry Medical University of ViennaViennaAustria Departmen. of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Departmen. of An.tomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical Un.versity of Vien.a Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Departmen. of Han.- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral n.rve in.uries in.uce a severe motor an. sen.ory deficit. Sin.e the availability of autologous n.rve tran.plan.s for n.rve repair is very limited, altern.tive treatmen. strategies are sought, in.ludin. the use of tubular n.rve guidan.e con.uits(tn.Cs). However, the use of tn.Cs results in.poor fun.tion.l recovery an. cen.ral n.crosis of the regen.ratin. tissue, which limits their application.to short n.rve lesion.defects(typically shorter than.3 cm). Given.the importan.e of vascularization.in.n.rve regen.ration. we hypothesized that en.blin. the growth of blood vessels from the surroun.in. tissue in.o the regen.ratin. n.rve within.the tn.C would help elimin.te n.crotic processes an. lead to improved regen.ration. In.this study, we reported the application.of macroscopic holes in.o the tubular walls of silk-based tn.Cs an. compared the various features of these improved silk^(+) tn.Cs with the tubes without holes(silk^(–) tn.Cs) an. autologous n.rve tran.plan.s in.an.8-mm sciatic n.rve defect in.rats. Usin. a combin.tion.of micro-computed tomography an. histological an.lyses, we were able to prove that the use of silk^(+) tn.Cs in.uced the growth of blood vessels from the adjacen. tissue to the in.ralumin.l n.ovascular formation. A sign.fican.ly higher n.mber of blood vessels in.the silk^(+) group was foun. compared with autologous n.rve tran.plan.s an. silk^(–), accompan.ed by improved axon.regen.ration.at the distal coaptation.poin. compared with the silk^(–) tn.Cs at 7 weeks postoperatively. In.the 15-mm(critical size) sciatic n.rve defect model, we again.observed a distin.t in.rowth of blood vessels through the tubular walls of silk^(+) tn.Cs, but without improved fun.tion.l recovery at 12 weeks postoperatively. Our data proves that macroporous tn.Cs in.rease the vascular supply of regen.ratin. n.rves an. facilitate improved axon.l regen.ration.in.a short-defect model but n.t in.a critical-size defect model. This study suggests that further optimizatio

关键词： axon.regen.ration blood vessel fun.tion.l recovery macroporous n.rve lesion peripheral n.rve repair sciatic n.rve silk-based n.rve guidan.e con.uit vascularization