G-度量空间中两对非相容映象的几个新的公共不动点定理

在G-度量空间的框架下,利用自映象对的非相容性和(Ag)型R-弱交换性条件,在既不要求空间的完备性,也不要求映象连续的条件下,建立了一类?-压缩条件下的4个映象的几个新的公共不动点定理,此定理在很大程度上改进和发展了已有文献的相关结果.     

Infinite Series Identities on Harmonic Numbers

By means of Abel’s lemma on summation by parts, we derive several infinite series identities, which involve the classical harmonic numbers and their variants.     

Multiple positive solutions of the singular boundary value problem for Sturm-Liouville equation with impulses on the half line

We consider the existence of multiple positive solutions of the singular boundary value problem for the Sturm-Liouville equation with impulses on the half line. By applying the fixed-point index theorem of a cone map, existence and multiplicity results about positive solutions are obtained. Our results improve and generalize some well-known results. An example is presented to demonstrate applications of our main results.     

Electronic structure of fluorinated and hydrogenated beryllium monoxide nanostructures

Using first‐principles calculations, we investigate the chemical functionalizations of beryllium monoxide (BeO) nanostructures by the fluorine and hydrogen atoms. We find that the hydrogenation weakens the Be–O bonds and causes the instability of semihydrogenated nanosheets, while the fluorination is energetically favorable and forms a stable semifluorinated conformation. More importantly, the semifluorinated BeO sheet exhibits an intrinsic half‐metallic behavior, which is robust with a large half‐metal gap and a high Curie temperature above room temperature. By the same strategy of fluorination, the half‐metallicity can also be achieved in the one‐dimensional BeO nanotubes and nanoribbons. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

氟烷基取代的双酚A类衍生物的合成

利用相转移催化剂十六烷基三甲基溴化铵(CTMAB)催化的连二亚硫酸钠引发的苯酚衍生物与含氟碘代烷的氟烷基化反应, 合成了含氟烷基取代的酚类化合物. 研究了双酚A与含氟碘代烷的氟烷基化反应, 得到了一类重要的含氟单体, 即含氟烷基取代的双酚A衍生物. 通过改变含氟碘代烷与双酚A的摩尔比, 可以得到单取代、二取代和四取代的含氟烷基双酚A衍生物.     

Interaction behaviours of solitoffs: fission, fusion, reconnection and annihilation

The interactions between solitoffs are extensively investigated. Besides the known solitoff fission and fusion interactions, two new types of solitoff interactions are discovered, named the solitoff reconnection and the solitoff annihilation. Taking the asymmetric Nizhnik--Novikov--Veselov equation as an illustrative system, five types of solitoff interactions are graphically revealed on the basis of the analytical solution obtained by the modified tanh function expansion method.     

A finite deformation second gradient theory of plasticity

Extending the previous work by Chambon et al. [2] to the finite deformation regime, a local second gradient theory of plasticity for isotropic materials with microstructure is developed based on the multiplicative decomposition of the deformation gradient, the additive decomposition of the second deformation gradient and the principle of maximum dissipation.     

Exact Solutions of the φ^6 ＋ φ^5 Model Using Truncated Method

In this letter, the φ^6 ＋ φ^5 model in （D ＋ 1） dimensions can be solved by a truncated series method. A series of solitary solutions of the φ^6 ＋ φ^5 model in （D ＋ 1） dimensions have be obtained.     

碳纳米管修饰金电极检测特定序列DNA

利用化学偶联法将末端修饰氨基的寡聚核苷酸固定在表面修饰有羧基化碳纳米管(CNTs-COOH)的金电极表面, 制备新型核酸探针, 可以特异性结合目标单链寡聚核苷酸. 以阿霉素作为嵌合指示剂, 利用示差脉冲法测定杂交的结果. 经过实验条件的优化, 测定DNA浓度在1.0×10^－6～1.0×10^－9 mol/L呈良好的线性关系. 检测限为: 2.54×10^－10 mol/L. 碳纳米管特有的纳米结构对检测结果的放大作用, 提高了该传感器的检测限和灵敏度.     

二元高阶Lipschitz函数类和二重Fourier级数

利用二元函数的(r,s)阶差分和二元连续模函数定义了二元周期函数的高阶Lipschitz函数类Λr,s(ω)和λr,s(ω),并且从函数Fourier级数的系数出发,在复数域内给出了函数属于二元周期函数类的充分条件,在实数域内给出了函数属于二元周期函数类的充要条件.