EXISTENCE AND UNIQUENESS OF THE SOLUTION FOR NONLINEAR THIRD-ORDER ROBIN BOUNDARY VALUE PROBLEM WITH A TURNING POINT

The paper aims to obtain existence and uniqueness of the solution as well as asymptotic estimate of the solution for singularly perturbed nonlinear third- order Robin boundary value problem with a turning point.In order to achieve this aim,existence and uniqueness of the solution for third-order nonlinear Robin boundary value problem is derived first based on the upper and lower solutions method under relatively weaker conditions.In this manner,the goal of this paper is gained by applying the existence and uniqueness results mentioned above.     

偶氮苯衍生物三阶非线性的四波混频研究

用皮秒Ｎｄ：ＹＡＧ激光器的倍频光（５３２ｎｍ）对具有离域π－共轭电子云结构的偶氮苯类样品材料作简并四波混频补给，测得三阶非线性电极化率ｘ＾（３）和它们的时间响应分别为１０＾－９ｅｓｕ和２０ｐｓ，并对影响ｘ＾（３）的瞬时光栅作用和ｘ＾（３）的响应时间人了讨论。     

Investigation on ultrafast thrid—order optical nonlinearity of metal（dmit）2／mnt）2 Charge transfer complexes

We have investigated the transient third-order optical nonlinearity of the solutions of Metal(dmit)2/(mnt)2 salts in acetone by employing femtosecond optical Kerr gate measurement at 830nm wavelength.An order of enhancement on the second-order hyperppolarizability is found for the above salts with central atoms of Cu and Ni.We have suggested an explanation for the enhancement based on the extension of electronic conjugation by the entring Cu or Ni atom.     

C_(74)的结构、电子光谱及三阶线性光学性质的理论研究

用密度泛函（DFT）方法（BLYP/3－21G~*）研究了C_(74)的稳定几何构型。用 ZINDO及ab initio GIS两种方法对C_(74)的电子光谱进行了计算，预测C_(74)在红 外区域有光谱吸收。计算了C_(74)的三阶非线性光学系数<γ>为1.483 * 10~(-32) esu，它比C_(60)的<γ>（8.84 * 10~(-34) esu）要大得多。预测C_(74)亦将是 一种有很好应用前景的磁性材料。     

Lattice Thermal Transport in the Homogeneous Cage-Like Compounds Cu3VSe4 and Cu3NbSe4: Interplay between Phonon-Phase Space,Anharmonicity, and Atomic Mass

Understanding the correlation between crystal structure and thermal conductivity in semiconductors is very important for designing heat-transport-related devices, such as high-performance thermoelectric materials and heat dissipation in micro-nano-scale devices. In this work, the lattice thermal conductivity ( ) of the cage-like compounds Cu₃VSe₄ and Cu₃NbSe₄ was investigated by experimental measurements and first-principles calculations. The experimental of Cu₃NbSe₄ is approximately 25 % lower than that of Cu₃VSe₄ at 300 K. The relevant important physical parameters, including the sound velocity, heat capacity, weighted phonon phase space (W), and third-order force constants along with atomic mass were theoretically analyzed. It is found that W is the dominant parameter in determining the , and the other factors only play a minor role. The physical origin is the relatively “soft” lattice of Cu₃NbSe₄ with heavier atomic mass. This research provides deep insight into the correlation between the thermal conductivity and crystal structure and paves the way for discovering high-performance thermal management device and thermoelectric materials with intrinsically low .     

三级相互作用对聚亚甲基链末端距四次矩的影响

本文用三级相互作用近似理论导出了高分子链末端距的四次矩的计算公式。计算聚亚甲基链的末端距四次矩,并同二级相互作用的结果进行了比较。对于聚亚甲基链,三级相互作用近似的四次矩小于二级相互作用近似的四次矩。     

Synthesis and property of soluble poly(1,1′-dialkyl-3,3′-ferrocenylenevinylene)s via titanium-induced dicarbonyl-coupling reaction of 1,1′-dialkylferrocene-3,3′-dicarbaldehydes

1,1′-Dialkylferrocene-3,3′-dicarbaldehydes ( 1a–c ) with long alkyl chains such as ethyl, hexyl, and dodecyl groups were prepared in 13–25% yield via three-step reactions. The titanium-induced dicarbonyl-coupling reaction of 1a–c gave poly(1,1′-dialkyl-3,3′-ferrocenylenevi-nylene)s ( 2a–c ) in quantitative yields, which were the molecular weights of 3000–10,000 and highly soluble in chloroform, benzene, and hexane. The electrical conductivity and the third-order nonlinear optical susceptibility for poly(1,1′-dihexyl-3,3′-ferrocenylenevinylene) ( 2b ) were estimated to be 1 × 10^?2 S/cm on doping with iodine and 1–4 × 10^?12 esu at a wavelength of 1–2.4 μm, respectively. © 1995 John Wiley & Sons, Inc.     

C60-吡咯烷衍生物的合成及非线性光学性质的研究

通过富勒烯C₆₀与肌氨酸和有机醛化合物的1,3-偶极环加成反应, 获得了九种含不同有机功能基团的C₆₀吡咯烷衍生物1～9, 用¹H NMR, ¹³C NMR, FTIR, UV-vis和FAB-MS进行了结构表征; 利用皮秒激光光源, 采用z扫描技术测定了分子的三阶非线性超极化率γ⁽³⁾, 结果显示: 化合物3 (γ⁽³⁾＝4.14×10^－33 esu)具有最大的三阶非线性光学系数, 说明增加噻吩共轭链的长度, 使三阶非线性活性增加; 对具有相同共轭链的C₆₀-噻吩吡咯烷衍生物(2, 5, 1和4), 吸电子取代基减小了三阶光学非线性活性, 给电子基增大了三阶光学非线性活性; 同时发现喹啉环2-位键联(7)比4-位(8)有更好的三阶光学非线性活性.     

一个奇摄动微分方程非线性混合边值问题

研究了一个三阶半线性微分方程的奇摄动非线性混合边值问题.利用边界层函数法构造了该问题的形式渐近解,并采用微分不等式理论证明了解的存在性,给出了渐近解的误差估计,最后得出了边界层函数指数型衰减的结论.     

金属有机骨架薄膜材料的三阶非线性光学性能研究进展

金属有机骨架(MOFs)材料因其可设计的结构以及灵活可控的配位模式,在三阶非线性光学(NLO)领域引起了广泛的关注。与液体分散状态相比,MOFs在固体状态下的三阶NLO性能更为重要,这不仅可以深入了解MOFs本身所固有的光学性能,还有助于实现MOFs在光学器件中的实际应用。然而,由于散射的存在和透光率的限制,单独的MOFs材料难以直接实现固体状态下的三阶NLO性能研究,将MOFs制备成具有较好光学透过性的薄膜是研究其NLO性能最为可行的一种策略。MOFs薄膜不仅很好地继承了MOFs所固有的三阶NLO性能,而且还结合了薄膜的高透光率以及灵活的机械性能。基于此,本文分析总结了MOFs薄膜的制备方法及其NLO性能研究方面的相关工作,并根据目前MOFs薄膜在三阶NLO性能方面的研究现状对其未来发展予以了展望。