物理模型教学与创新能力的培养

现代教学以能力培养为重点.学生获得研究问题、探索问题的能力是十分重要的,物理模型的教学过程对培养学生研究问题、探索问题、发展创造思维、培养辩证唯物主义思想方法都极为有利,因此,必须重视物理模型教学.     

Synthesis,structure, spectroscopic and magnetic properties of a novel two-dimensional copper(II) complex Na2[Cu(pba)] · 6H2O [pba = 1,3-propylenebis(oxamato)]

The copper(II) complex Na₂[Cu(pba)] · 6H₂O has been synthesized and its structure determined. It consists of a novel two-dimensional network of [Cu(pba)]^2– anions connected to each other through the sodium ion as a bridge. Spectroscopic and magnetic properties have been measured and a spin distribution calculation has been carried out with the GAUSSIAN-94. Theoretical calculations indicate the rather larger spin density on nitrogen atoms should be responsible for the satellite lines appearing beside the main hyperfine coupling signs of copper(II). The antiferromagnetic interaction may be due to the intermolecular interaction and/or different copper(II) ions through the Na⁺ bridge in the same layer.     

Jensen's inequality for g-expectation: part 1

Briand et al. (Electron. Comm. Probab. 5 (2000) 101–117) gave a counterexample and proposition to show that given g,g-expectations usually do not satisfy Jensen's inequality for most of convex functions. This yields a natural question, under which conditions on g, do g-expectations satisfy Jensen's inequality for convex functions? In this paper, we shall deal with this question in the case that g is convex and give a necessary and sufficient condition on g under which Jensen's inequality holds for convex functions. To cite this article: Z. Chen et al., C. R. Acad. Sci. Paris, Ser. I 337 (2003).     

Synthesis and characterization of a polyfluorene containing carbazole and oxadiazole dipolar pendent groups and its application to electroluminescent devices

We have synthesized a blue‐light‐emitting polyfluorene (PF) derivative ( PF‐CBZ‐OXD ) that presents bulky hole‐transporting carbazole and electron‐transporting oxadiazole pendent groups functionalized at the C‐9 positions of alternating fluorene units. The results from photoluminescence and electrochemical measurements indicate that both the side chains and the PF main chain retain their own electronic characteristics in the copolymer. An electroluminescent device incorporating this polymer as the emitting layer was turned on at 4.5 V; it exhibited a stable blue emission with a maximum external quantum efficiency of 1.1%. Moreover, we doped PF‐CBZ‐OXD and its analogue PF‐TPA‐OXD with a red‐light‐emitting iridium phosphor for use as components of phosphorescent red‐light emitters to investigate the effect of the host's HOMO energy level on the degree of charge trapping and on the electrophosphorescent efficiency. We found that spectral overlap and individual energy level matching between the host and guest were both crucial features affecting the performance of the electroluminescence devices. Atomic force microscopy measurements indicated that the dipolar nature of PF‐CBZ‐OXD , in contrast to the general nonpolarity of polydialkylfluorenes, provided a stabilizing environment that allowed homogeneous dispersion of the polar iridium triplet dopant. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2925–2937, 2007     

半导体激光器发射光谱实验仪

设计了一种半导体激光器发射光谱实验仪 ,可以用来观测LD发射的荧光光谱、激光光谱 ,以及了解光栅外腔选取单纵模、压窄线宽、波长调谐的机理 .该实验仪结构紧凑 ,物理概念清晰 ,适用于大专院校的光学实验教学     

Buckling of a stiff thin film on a compliant substrate in large deformation

A finite-deformation theory is developed to study the mechanics of thin buckled films on compliant substrates. Perturbation analysis is performed for this highly nonlinear system to obtain the analytical solution. The results agree well with experiments and finite element analysis in wavelength and amplitude. In particular, it is found that the wavelength depends on the strain. Based on the accurate wavelength and amplitude, the membrane and peak strains in thin films, and stretchability and compressibility of the system are also obtained analytically.     

组织合作中关系专用性投资最优水平分析

本在以往研究的基础上对关系专用投资的价值创造功能作了进一步的讨论，分析了其创造准租金收入的机理和一般表示，在此基础上结合以往交易成本经济学对关系专用性投资的认识以及其作为沉没成本的特征，从效用最大化的角度建立了两个成员的联盟中关系专用性投资的决策模型，分析了关系专用性投资创造准租的具体特征对投资水平的影响。     

Proper holomorphic self-maps of smooth bounded Reinhardt domains in C~n

It is proved that every proper holomorphic self-map of a smooth bounded Reinhardt domain of D'Angelo finite type in Cn (n > 1) is an automorphism.     

Low Cost, High Efficiency, Gain Flattened L Band EDFA Using FBGs as C Band Seed Generators

A low cost, coolerless 980nm diode pumped, gain flattened L band EDFA with fast transient control, high pump efficiency and gain clamping effect was realized by using FBGs as C band seed generators.     

Crystallographic report: Diiodo[tris(2‐pyridyl)amine]mercury(II), [(C5H4N)3N]HgI2

In mononuclear HgI₂[(C₅H₄N)₃N], mercury is tetrahedrally coordinated by two nitrogen atoms of a tris(2‐pyridyl)amine ligand and two iodides. The coordination moieties are connected by weak intermolecular Hg(II)···I interactions to give a one‐dimensional structure. Copyright © 2003 John Wiley & Sons, Ltd.