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41.
S. Park T. U. Kampen T. Kachel P. Bressler W. Braun D. R. T. Zahn 《Applied Surface Science》2002,190(1-4):376-381
The interaction of Ag and In with a thin film of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) was studied by near-edge X-ray absorption fine structure (NEXAFS). Upon Ag deposition on a PTCDA film of 20 nm thickness the relative intensities and lineshapes, as well as the angular dependence of the spectra remains unchanged, illustrating the formation of a chemically unreactive Ag/PTCDA interface. On the other hand, the adsorption of 0.3 nm In strongly decreases the intensity of the π* resonances in C and O K-edge NEXAFS spectra. This is attributed to a strong charge transfer between In and PTCDA, leading to a redistribution of the charge in the molecule. However, the absence of a strong shift or new features and negligible dependence of peak intensities corresponding to π* resonances on the In thickness indicate that the interaction between In and PTCDA is not accompanied by a covalent bond formation. 相似文献
42.
在手征SU(3)夸克集团模型下, 通过共振群方法(RGM)计算了双Λ超核^6_ΛΛHe,^5_ΛΛHe,^5_ΛΛH,^4_ΛΛHe,和^4_ΛΛH的结合能. 结果表明, 假定双Λ超核具有双Λ集团和壳心核集团构成的两集团结构, 得到的^6_ΛΛHe超核的结合能与实验值基本吻合, 表明手征SU(3)夸克集团模型不仅能较好地描述重子谱、N-N和Y-N相互作用及轻Λ超核的结合能, 也能较好地描述Y-Y相互作用及双Λ超核^6_ΛΛHe,^5_ΛΛHe,^5_ΛΛH,^4_ΛΛHe,和^4_ΛΛH的结合能, 指出了它们存在的可能性. 相似文献
43.
Wei‐Ling Wang Jian‐Wei Xu Yee‐Hing Lai 《Journal of polymer science. Part A, Polymer chemistry》2006,44(13):4154-4164
Bipyridinophane–fluorene conjugated copolymers have been synthesized via Suzuki and Heck coupling reactions from 5,8‐dibromo‐2,11‐dithia[3]paracyclo[3](4,4′)‐2,2′‐bipyridinophane and suitable fluorene precursors. Poly[2,7‐(9,9‐dihexylfluorene)‐co‐alt‐5,8‐(2,11‐dithia[3]paracyclo[3](4,4′)‐2,2′‐bipyridinophane)] ( P7 ) exhibits large absorption and emission redshifts of 20 and 34 nm, respectively, with respect to its planar reference polymer Poly[2,7‐(9,9‐dihexylfluorene)‐co‐alt‐1,4‐(2,5‐dimethylbenzene)] ( P11 ), which bears the same polymer backbone as P7 . These spectral shifts originate from intramolecular aromatic C? H/π interactions, which are evidenced by ultraviolet–visible and 1H NMR spectra as well as X‐ray single‐crystal structural analysis. However, the effect of the intramolecular aromatic C? H/π interactions on the spectral shift in poly[9,9‐dihexylfluorene‐2,7‐yleneethynylene‐co‐alt‐5,8‐(2,11‐dithia[3]paracyclo[3](4,4′)‐2,2′‐bipyridinophane)] ( P10 ) is much weaker. Most interestingly, the quenching behaviors of these two conjugated polymers are largely dependent on the polymer backbone. For example, the fluorescence of P7 is efficiently quenched by Cu2+, Co2+, Ni2+, Zn2+, Mn2+, and Ag+ ions. In contrast, only Cu2+, Co2+, and Ni2+ ions can partially quench the fluorescence of P10 , but much less efficiently than the fluorescence of P7 . The static Stern–Volmer quenching constants of Cu2+, Co2+, and Ni2+ ions toward P7 are of the order of 106 M?1, being 1300, 2500, and 37,300 times larger than those of P10 , respectively. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4154–4164, 2006 相似文献
44.
Bandcrossing in 31 rotational bands of 25 different odd-A nuclei in the rare-earth region has been analysed by using a two-band mixing formalism with a constant band interaction within
the framework of the effective decoupling picture. The interband interaction strengthV between the one-quasiparticle band and the three-quasiparticle band exhibits a variation with the neutron number which is
not different from the oscillatory behaviour observed in even-even nuclei and does not show signs of any appreciable phase
shifting as predicted by theory. However, the overall range of variation ofV is greater than that observed in even-even systems. 相似文献
45.
LIU Biao BAO Yong-li WEI Zhuang WU Yin MENG Xiang-ying LI Yu-xin YIN Wei-tian 《高等学校化学研究》2006,22(2):217-220
Introduction Activinisamemberofthetransforminggrowth factor(TGF)βsuperfamilyofextracellularsignaling proteins.Themembersofthisfamilyplayacriticalrole duringembryogenesisandinmaintainingtissuehomeo stasisinadultlife[1—3].DeregulatedTGFfamilysigna lingisi… 相似文献
46.
WANG Jiang-yun GU Wen WANG Wen-zhen LIU Xin LIAO Dai-zheng 《高等学校化学研究》2006,22(3):283-286
Introduction Itiswell knownthatcyanogroupsincyanometa latessuchas[Ag(CN)2]-unitscanbeusedasbridg ingligandsandapolymericstructurecanbeformed throughsilver silver(argentophilic)interactions.This propertyhasbeenexploredintheconstructionofmany oligomericandp… 相似文献
47.
This paper analyses and models the dynamic interaction among permeable multi-cracks in a piezoelectric strip under anti-plane shear waves by the Schmidt method. The Fourier transform is applied and then two pairs of triple integral equations can be solved using the Schmidt method. The results show that the stress and the electric displacement intensity factors of cracks depend on not only the crack length and the piezoelectric coefficient, but also the thickness of the piezoelectric strip, the distance between multi-cracks and the frequency of incident wave. 相似文献
48.
An acoustic pulse propagating on a two-mode fiber can act as a beam splitter in a scanning interferometer. When this device
is employed in white-light interferometry, the effects of distributed coupling and dispersive interferometer arms need to
be considered. A theory suitable for treating acousto-optic interaction of partially coherent light in a moving interaction
region was developed. It was found that differential optical dispersion should be negligible and the acoustic pulse length
short. Also the coherence time should be short but long compared to the intermodal group delay difference over a pulse length.
Experiments with long acoustic pulses were performed, and fairly good agreement with theory was obtained. 相似文献
49.
A fifth-order theory for solving the problem of interaction between Stokes waves and exponential profile currents is proposed.
The calculated flow fields are compared with measurements. Then the errors caused by the linear superposition method and approximate
theory are discussed. It is found that the total wavccurrent field consists of pure wave, pure current and interaction components.
The shear current not only directly changes the flow field, but also indirectly does so by changing the wave parameters due
to wave-current interaction. The present theory can predict the wave kinematics on shear currents satisfactorily. The linear
superposition method may give rise to more than 40% loading error in extreme conditions. When the apparent wave period is
used and the Wheeler stretching method is adopted to extrapolate the current, application of the approximate theory is the
best.
Project supported by the Chinese Academy of Sciences. 相似文献
50.
用三维样边界元法分析水闸闸室结构。底板,闸墩和载水墙等为其子结构,交通桥,工作桥和胸墙等处理为内部支撑。地基和边载可以是任意的,只要能给定地表位移面力关系。在各种工况下,不论是设置平板门还是弧形门,是平底板是反拱底板,即使在稀疏剖分下也能给出高精度的位移场,应力场和地基反力场。 相似文献