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991.
A. KHAKSARI M. ERSHAD H. SHARIF 《数学学报(英文版)》2006,22(4):1189-1196
Strongly irreducible submodules of modules are defined as follows: A submodule N of an Rmodule M is said to be strongly irreducible if for submodules L and K of M, the inclusion L ∩ K ∈ N implies that either L ∈ N or K ∈ N. The relationship among the families of irreducible, strongly irreducible, prime and primary submodules of an R-module M is considered, and a characterization of Noetherian modules which contain a non-prime strongly irreducible submodule is given. 相似文献
992.
Xin-yu Song Lan-sun ChenDepartment of Mathematics. Xinyang Teachers College Henan ChinaInstitute of Mathematics Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing China 《应用数学学报(英文版)》2002,18(3):423-430
The dynamics of a predator-prey system, where prey population has two stages, an immature stage and a mature stage with harvesting, the growth of predator population is of Lotka-Volterra nature, are modelled by a system of retarded functional differential equations. We obtain conditions for global asymptotic stability of three nonnegative equilibria and a threshold of harvesting for the mature prey population. The effect of delay on the population at positive equilibrium and the optimal harvesting of the mature prey population are also considered. 相似文献
993.
C. W. Lim 《Acta Mechanica Solida Sinica》2011,24(6):484-494
The torsional static and dynamic behaviors of circular nanosolids such as nanoshafts, nanorods and nanotubes are established based on a new nonlocal elastic stress field theory. Based on a new expression for strain energy with a nonlocal nanoscale parameter, new higher-order governing equations and the corresponding boundary conditions are first derived here via the variational principle because the classical equilibrium conditions and/or equations of motion can- not be directly applied to nonlocal nanostructures even if the stress and moment quantities are replaced by the corresponding nonlocal quantities. The static twist and torsional vibration of circular, nonlocal nanosolids are solved and discussed in detail. A comparison of the conventional and new nonlocal models is also presented for a fully fixed nanosolid, where a lower-order governing equation and reduced stiffness are found in the conventional model while the new model reports opposite solutions. Analytical solutions and numerical examples based on the new nonlocal stress theory demonstrate that nonlocal stress enhances stiffness of nanosolids, i.e. the angular displacement decreases with the increasing nonlocal nanoscale while the natural frequency increases with the increasing nonlocal nanoscale. 相似文献
994.
业务模式现在是许多公司的核心。为了测试这些模式的有效陛,有一个研究团队在持续跟踪一个组织的绩效…… 相似文献
995.
Conjugatedpolymerswithlargethird-orderopticalnonlinearityhavebeedfocusedfortheirpromisingpotentialsforadvancedmaterialsapplications'.Recently,investigationsoftransitionmetalwithorganicligandsystemshavebeengreatlyintensifiedduetothedelectronsincorporatedintheconjugatedsystem,whichareexpectedtoellhancethehyperpolarizability.Phenylacetyleneandthemetalphenylacetylidesplayimportantrolesinformationofuniquecoordinatedc-lusters',butitseamsthatthestudyofmetalphenylacetylides,particularlyofthesilverphen… 相似文献
996.
SinceTangetaldevelopedanoveltWo-layerorganicelectr0luminescentdevice(OELD)inl987successfully',OELDhasattractedmuchinterestall0verthew0rId.ltisregardedas"havingbr0ughtthethirdrev0luti0ntoflatpaneldisplay"',becauseithass0manyadvantagessuperiort0CathodeRayTube(CRT)andLiquidCrystalDevice(LCD).Ithasl0wdrivenvoltage(lO0,000cd/m=),highluminescentefficiency(l5lIn/w),goodstability(50,000h),andithassimplestructureandiseasytofabricate'.ComparedtoinorganicELD,OELDiseasie… 相似文献
997.
把Reissner-Nordstrom 《物理学报》2000,20(1):581-585
999.
Gush.()(/i'leleluBI.isapronlinenttraditionalchineseherbmedicinei.Studiesonthecllenlicalcollstituentsofthisplantwerestartedtwentyyearsago=1andsincethenman}'papershavebeenpublished=-'.However.previouswork1hostlyreportedtheisolationsofphenolcompoundsincludingtheirglycosides=-'.Duringourreinvestigatingonthisplant,di-(p-hydroxybenzyl)hydroxylamineI(Figurel)wasisolatedanditsstructurewaselucidatedonthebasisofHRFABMS(highresolutiontestatombombardmentmassspectroscopy),and1DandZDNMRexperiments.Po… 相似文献
1000.
In this paper, we discuss numerous sets of global parametric sufficient efficiency conditions under various generalized (α, η, ρ)-V-invexity assumptions for a semiinfinite multiobjective fractional programming problem. 相似文献