Codiameters of 3‐connected 3‐domination critical graphs

A graph G is 3‐domination critical if its domination number γ is 3 and the addition of any edge decreases γ by 1. Let G be a 3‐connected 3‐domination critical graph of order n. In this paper, we show that there is a path of length at least n?2 between any two distinct vertices in G and the lower bound is sharp. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 76–85, 2002     

Photochemistry of dibenzo-1,4-dioxins: intramolecular rearrangement-reduction through observable 2,2′-biphenylquinones

The photochemistry of dibenzo-1,4-dioxin (7) and 2,3,7,8-tetramethyldibenzo-1,4-dioxin (15) — both of which have the parent ring system of the well-known enrimental contaminant dioxin— has been studied in aqueous solution and in selected organic solvents. It is shown that a novel intramolecular photorearrangement is the major mode of reaction for 7 and the exclusive reaction for 15, giving rise to observable (by UV—Vis spectrophotometry) intermediate 2,2′-biphenylquinones. Subsequent reduction by the organic co-solvent gives rise to 2,2′-biphenols as major or exclusive product. Thus, photolysis of these compounds generates oxidizing agents in the biphenylquinones. Photolysis in the presence of added N_aBH₄ resulted is greatly enhanced yields of biphenols along with more than 90% material balance. These findings have relevance to dioxin photodecomposition, which can be used as a method for its destruction.     

VISCOSITY SOLUTION THEORY OF A CLASS OF NONLINEAR DEGENERATE PARABOLIC EQUATIONS Ⅰ. UNIQUENESS AND EXISTENCE OF VISCOSITY SOLUTIONS

ThisresearchissupportedbytheNationalNaturalSciencesFoundationofChina.1.IntroductionInthispaper,weseektoestablishthecomparisonprinciple,regularity,ekistenceandsomegeometricpropertiesoftheinterfaceoftheviscositysolutionsforthefollowingfullynonlineardegenerateequations(Problem(C)):withFsatisfyingthefollowingassumptions:Fisdegenerateparabolic,i.e.F(q,X Y)5F(q,X),VY20,whereSadenotesthespaceofnxnsymmetricmatriceswiththeusualordering.wherellXlll~ItrX l ltrX--l,X~X X--,X 20,X--50,A,B20,p>2…     

有限体积KFVS方法在二维溃坝中的应用

本文采用了基于KFVS格式的有限体积方法 (FVM)求解了控制水流运动的二维浅水方程 ,建立了二维水坝瞬间溃坝的洪水演进模型 .并应用此模型模拟了二维非对称溃坝和对称溃坝情形下坝左下角有障碍物时的洪水波演进过程 .模拟结果表明该数学模型对二维浅水运动的模拟很有效 .     

Modification to the Fringe Component of Diffraction Coefficient in TD-EEC Method

A modified formulation for fringe component of diffraction coefficient is implemented to TD-EEC method. An example of diffraction by perfectly conducting plate is used to illustrate our scheme. Comparing with the FDTD results we observe that the improved expression for fringe component is more accurate than that of Michaeli's formulation. This high frequency time domain technique is available for treating the bistatic scattering problems for millimeter waves.     

严格单调似然比分布族的完全类定理

引言和主要结果设X是一维随机变量,其分布函数为;。={F_θ:θ∈Θ}此处,v 为σ有限测度.记(?)={F_θ:θ∈Θ}.设参数空间Θ和行动空间(?)都是 R_1的子集,损失函数 L(θ,α),对每一个固定的θ,是α的下半连续函数,且存在θ的单调上升函数 q(θ),使a)对每一个固定的θ,L(θ,α)在α=q(θ)处达到极小,且当 α>q(θ)时非降,当αα有 L(θ_α,α′)>     

北京自由电子激光最近进展──实现饱和振荡

北京自由电子激光(BFEL)装置于1993年底在10.68μm处实现了饱和振荡.输出激光能量为3mJ,饱和平顶宽度2μs.对应饱和振荡平均功率为210kW(宏脉冲),峰值功率约为20MW,比自发辐射高8个量级,单程小讯号净增益为24%,转换效率为0.45%,与理论预期结果相符.光束质量接近衍射极限.目前装置可工作于9-11μm.     

一个反应扩散方程的自由边界问题

该文研究了一个描述原细胞生长的反应扩散方程的自由边界问题.利用非线性分析中的线性化思想和偏微分方程的估计理论,证明了该自由边界问题局部古典解的存在唯一性.     

浅谈毕奥-萨伐尔定律的简单推证

本文以磁荷、磁极相互作用的库仑定律、电流元可作为产生磁场的源及牛顿第三定律为出发点 ,简单推导出毕奥 萨伐尔定律     

氧氟沙星和左氟沙星与人血清白蛋白的相互作用研究

用光谱技术研究了水溶液中氧氟沙星(OFLX)和左氟沙星(LVFX)与人血清白蛋白相互作用的机制.荧光猝灭法测得的结果表明反应的结合常数为KOFLX＝0.482×105L@mol-1,KLVFX=0.529×105L@mol-1,结合位点数nOFLX＝0.72,nLVFX=0.74.按照Fōorster非辐射能量转移理论得到药物-蛋白之间的结合距离分别为rOFLX=2.94nm,nVFX=2.85 nm.实验结果说明OFLX与LVFX在体内与蛋白结合直到运输到受体部位这一环节基本相同.