Prey-predator systems with intertwined basins of attraction

In this article, we show the existence of intertwined basins of attraction for a class of prey-predator systems, which improves the extant results by deleting some crucial and hard testing conditions.     

Studies on the SFD Properties of NdxGd1-xCa4O(BO3)3 Solid-solution Crystal

NdxGd1-xCa4O(BO3)3 (NdGdCOB) is a new self-frequency-doubling (SFD) solid-solution crystal. The second-harmonic generation (SHG) phase-matching (PM) curves were calculated by using refractive indices. The deff of NdGdCOB crystal along different PM directions were calculated according to the sellmeier equation and dijk data in which the (θ=66.8°, φ=132.6°) PM direction has the highest deff. SFD experiments were carried out with Ti:sapphire CW laser and pulsed dye-laser. A green laser output power up to 225 mW at 530 nm was achieved from a 7×3×3 mm3 crystal sample pumped by 1560 mW CW Ti:sapphire laser. The lasing threshold of SFD was lower than 1.8 mW along the PM direction (66.8°,132.6°). The optical-optical conversion efficiency was 14.4%. The conversion efficiency was 7.7% when 10×3×3 mm3 sample was side-pumped by the pulsed dye-laser tuned to 595.4 nm with 17.5 mJ energy and the lasing threshold is 1.2 mJ.     

Apollonian等距与Mbius变换

设D是~2中至少包含三个边界点的单连通区域,对任意x,y∈D,α_D(x,y)表示D中关于x,y两点的Apollonian度量．1998年A．F．Beardon猜测：若f：D→D是Apollonian等距映射,则f必是D上的Mbius变换．在该文中作者对D是圆的情况肯定并证明了A．F．Beardon的上述猜想．     

Inequalities for the generalized elliptic integrals and modular functions

In this paper, the authors study monotonicity and convexity of the generalized elliptic integrals and certain combinations of these special functions, such as ma(r) and μa(r). Making use of these results, the authors obtain some sharp inequalities for the so-called Ramanujan's generalized modular functions.     

Weierstrass型函数图象的分形维数

考虑函数f(x)=sum from i=1 to ∞(?)~(-1)φ((?) θ_n)和w(x)=sum from n=1 to ∞(?)φ_(?)((?)x θ_(?)),式中0<α<(?)是任意实数,在一定条件下,估计了函数f图象的Hausdorff维数的下界,并求得了w函数图象的Box维数和Packing维数。     

Liénard方程的比较原理

本文证明了一个比较原理，使方程x" f(x)x' g(x)=0的周期解存在性定理可以用来判断方程x" h(x，x')x' g(x)=0的周期解的存在性．     

再散射输运模型与K+/π+比的系统学

用含再散射效应的简单的强子输运模型,研究了AGS能量(14.6AGeV/c)下p+p、p+Au和Si+Au反应的K⁺/π⁺比值,再现了该比值由P十P到Si十Au不断增长的实验事实.CERN能量(200AGeV/c)和AGS能量下,K⁺/π⁺比值相近的实验事实也得到了解释.     

细长竖直管路内自然对流沸腾临界热通量研究

l引言管内或窄小流路内的自然对流沸腾CHF的研究比较少。文献［1～41对水及氟里昂系等液体进行了实验，在Kutataladze【’］的池内沸腾无量式基础上，提出如下经验公式当L／De－－＋0时上式退化为池内沸腾公式。式中qm。x是临界热通量；Hi。是蒸发潜热；。是汽液界面张力；尸l和p。分别是液体和蒸汽的密度；9是重力加速度；c是实验常数；不同研究者之间相差很大。当L／De较大时各经验公式的计算值会相差l～2倍。式（1）没有任何物理机理的支持，仅以J和L／De之间的无量纲关系对实验值进行统计整理，对物性的实际影响、De独立于L／De的…     

基于土质边坡塑性极限分析条分法的可靠度计算方法研究

从土塑性极限分析上限定理出发,以土质边坡塑性极限分析条分法为基础,在引入可靠性分析方法(JC法)后,建立了土质边坡塑性极限分析条分法可靠度极限状态方程,并推导得到了塑性极限分析条分法可靠度计算公式。这种方法实现了定值计算向不确定性计算的转变,同时可靠度指标β的计算结果具有概率的意义。     

粉喷桩单桩承载力确定方法的比较

粉喷桩在高速公路软土地基处理中得到了广泛的应用,但其承载力的合理确定是工程实际中关心的一个重要问题。通过对工程中常用的几种粉喷桩单桩承载力确定方法的比较,分析了各自存在的问题和适用条件,提出了在实际工程应用中确定水泥搅拌桩单桩承载力的选用建议。