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941.
The reaction of Na(2)Se with cis-dichloroethene yielded (Z,Z,Z,Z,Z)-1,4,7,10,13-pentaselenacyclopentadeca-2,5,8,11,14-pentaene (15-US-5) and (Z,Z,Z,Z,Z,Z)-1,4,7,10,13,16-hexaselenacyclooctadeca-2,5,8,11,14,17-hexaene (18-US-6). X-ray crystallographic analysis of 15-US-5 and 18-US-6 revealed an all-cis geometry around the carbon-carbon double bonds, with all of the selenium atoms located on one side of the respective ring planes. 15-US-5 and 18-US-6 were also found to be oxidized more easily than the corresponding sulfur analogues. The complexation of 15-US-5 and 18-US-6 with silver trifluoroacetate afforded Ag(I)(15-US-5)(CF(3)COO) and Ag(I)(5)(18-US-6)(3)(CF(3)COO)(5), respectively. [reaction: see text] 相似文献
942.
943.
Tadahiro Nakamoto Motomi Katada Satoshi Kawata Susumu Kitagawa Hirotoshi Sano Michiko Konno 《Hyperfine Interactions》1994,93(1):1567-1572
Mixed-valence trinuclear iron propionates [Fe
2
III
FeIIO(C2H5CO2)6(py)3]npy, wheren=0, 1.5, were synthesized and the structure of the pyridine-solvated complex was determined by single-crystal X-ray diffraction. Mössbauer spectra of the solvated propionate complex showed a temperature-dependent mixed-valence state related to phase transitions, reaching an almost delocalized valence state at room temperature. On the other hand, the non-solvated propionate showed a remarkable change of the spectral shape related to a phase transition, remaining in a localized valence state at higher temperatures up to room temperature. 相似文献
944.
Measurements of Raman scattering were performed on GaAsAlAs superlattices. The lattice period ranged from 12 to 3000 Å. Phonon frequencies were shifted by changing the layer thickness. Qualitative expression of this shift and crystalline perfection are discussed. 相似文献
945.
Blazed ion-etched holographic gratings with a high absolute diffraction efficiency, good diffracted wavefront, high resolution, and low stray light have been produced. The performances were proved to be the same as, or superior to, commercially available blazed gratings produced by a ruling technique. 相似文献
946.
947.
Free boundary problem for the equation of one-dimensional motion of compressible gas with density-dependent viscosity 总被引:3,自引:0,他引:3
We consider a free boundary problem for the equation of the one-dimensional isentropic motion with density-dependent viscosity
μ =b
ϱ
β, whereb and β are positive constants. We prove that there exists an unique weak solution globally in time, provided that β<1/3.
Sunto Si considera un problema di frontiera libera per l’equazione del moto unidimensionale isoentropico con viscosità dipendente dalla densità secondo la legge μ =b ϱ β, doveb e β sono costanti positive. Si dimostra che esiste un’unica soluzione debole globale nel tempo, purché β<1/3.相似文献
948.
949.
Y. Kobayashi M. Katada H. Sano T. Okada K. Asai N. Sakai S. Ambe F. Ambe 《Hyperfine Interactions》1988,41(1):487-490
Mössbauer spectra at 5 K and magnetic susceptibilities from 4 K to room temperature have been measured on samples of anhydrous ruthenium trichlorides. The Mössbauer spectrum of α-RuCl3 shows a magnetic hyperfine splitting in agreement with the result of magnetic susceptibility measurement, while β-RuCl3 is found to be paramagnetic down to 4 K. 相似文献
950.
Photoluminescence and laser oscillation from In0.2Ga0.8As/GaAs strained-layer superlattices were measured under pulse-light excitations. Double-peak spectra were obtained, in contrast to the lattice-matched super-lattices. 相似文献