一类平面三次系统的极限环

本文给出原点为细焦点的三次系统｛ｘ＝－ｙ＋ａｘ＾３＋βｘ＾２ｙ＋λｘｙ＾２ ｙ＝ｘ＋ρｘ＾３＋αｘ＾２ｙ＋βｘｙ＾２＋λｙ＾３ （１）当ρ〉０时存在或不存在极限环的条件。     

Jane Eyre,a Plain but Spectacular semi-autobiographic Portrait of Charlotte Bronte

Maybe life itself is a endured suffering. This is a story about a special and unreserved woman who has been exposed to a hostile environment but continuously and fearlessly struggling for her ideal life. It is interpreted as a symbol of the independent spirit.Through Jane Eyre,Charlotte Bronte realized her own dream and life pursuit.There she was the master of her own fate.     

家庭的消费行为规律

家庭是社会消费的基本单位,大多数商品都是直接供家庭购买与消费的。即使是家庭个体成员的消费,也会受到家庭各方面因素的直接或间接的影响。家庭特征与家庭消费行为规律之间存在一定联系,尤其是家庭经济收入、家庭类型、家庭生命周期、家庭消费角色对家庭消费行为有很大的影响作用。探讨家庭的消费行为规律,对工商企业制定合理的营销策略有重要的意义。     

大丰国家级自然保护区麋鹿的种群动态

通过编制大丰自然保护区麋鹿种群生命表，绘制其种群增长曲线、死亡率曲线以及存活曲线。得出麋鹿种群的生理期望寿命为6．29岁；种群呈指数增长，其增长模型为Nt=39e^0.184t；种群年龄在1～7a时，种群死亡率较小，存活机率较大，到第8年后，种群死亡率急剧上升，存活机率较小。     

新马克思主义文艺学:本体论的新拓展--王元骧文学原理的哲学思考之三

本体论的新拓展是王元骧新马克思主义文艺学的组成部分之三,也是王元骧文学原理的哲学思考之三。本文由自然本体论、人类本体论和生命本体论三大系列建构而成。而其中的生命本体论源于康德的人类本体论,是叔本华的意志哲学/生命本体论关于原始欲望、本能冲动的“生命意志”学理。王元骧不仅将它引进新马克思主义文艺学,而且还把狄尔泰的生命哲学美学、叔本华的悲剧理念和尼采的强力意志等合理内核借鉴到新马克思主义文艺学,对以前很少问津的本体论予以新拓展。这是王元骧文学原理的哲学思考之后的超越。     

Synergetic effect of multiple phases on hydrogen desorption kinetics and cycle durability in ball milled MgH2–PrF3–Al–Ni composite

A new Mg MgH₂–PrF₃–Al–Ni composite was prepared by ball milling under hydrogen atmosphere. After initial dehydrogenation and rehydrogenation, Pr₃Al₁₁, MgF₂, PrH₃ and Mg₂NiH₄ nanoparticles formed accompanying the main phase MgH₂. The hydrogen absorption-desorption properties were measured by using a Sieverts-type apparatus. The results showed that the Mg MgH₂–PrF₃–Al–Ni composi...     

FC-空间的乘积空间内R-KKM型定理及其应用

对具有紧闭值的R-KKM映射簇证明了一个R-KKM型定理.作为应用,一个聚合不动点定理和一个匹配定理被证明.这些定理推广了近期文献中的结果.     

丢番图方程ax^2＋by^2=z^（3^n）整数解族问题研究

研究了丢番图方程x2＋axy＋y2=z2,ax2＋b2y=z3n和x2＋pxy＋y2=z2n整数解族问题,给出了它们的整数解族公式。     

薄壁构件的高温低周疲劳寿命的预测与验证

提出了文题的计算模型,它采用非线性弹塑性蠕变有限元法,计算构件危险点在高温及周期保载的交变载荷谱作用下的应力应变响应,以应变范围区分法累积损伤,从而求出构件的疲劳寿命,并以带孔矩形薄板为例作了计算与验证,结果吻合较好,可供工程应用。     

Ramet population ecology of Panicum virgatum in the field - Competitively random growth of ramets and foraging behavior of ramet populations

The authors investigated the heterogeneous size patterns and dynamic growth of the ramet population of Panicum virgatum, a clonal caespitose plant, limited to the space occupied by a ramet bunch and the time of the ramet yearly life cycle, to understand the ecology of clonal caespitose plants in the field, where the ramet bunch generally consisted of more than one genet. Dynamic life tables for ramet populations were established by the replacement of living ramets at the present time with "dead" ones in past time. These tables revealed stable coexisting patterns of isometric and allometric growing processes of ramets in mass and height respectively, which approximately followed the historic trajectory of a density-independent population. The ecology of clonal caespitose plants is further discussed based on the competitively random growth of ramet individuals, including the scale of foraging behavior. In the field, the ramet population ecol-ogy of switchgrass may be a statistical result of competitively random growth of ramet individuals. The foraging behavior of a ramet population could then be presented as a process in which ramet individuals competed with each other for light and grew randomly, whileat the same time a relatively stable dynamic growth pattern was apparent at the level of the ramet population, and the functional leaves were placed properly in time and space.