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61.
Acta Mathematica Hungarica - 相似文献
62.
Christian R. Samanamu Monika L. Amadoruge Charles S. Weinert James A. Golen Arnold L. Rheingold 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1389-1395
Abstract We have employed the hydrogermolysis reaction for the preparation of rare branched oligogermanes, and have obtained for the first time the X-ray crystal structures of several branched tetragermanes, including (Ph3Ge)3GePh, (Ph3Ge)3GeH, and (Ph3Ge)3GeX (X = Cl or Br). We also have at our disposal branched tetragermanes having the formula (EtOCH2CH2Bu n 2Ge)3GePh, where the ethoxyethyl substituent serves as a protecting group for a germanium–hydride active site. These reagents have been employed for the stepwise synthesis of higher branched systems having up to 13 bonded germanium atoms in the oligomer backbone. The synthesis, structures, and physical characteristics of these systems are described. GRAPHICAL ABSTRACT 相似文献
63.
Balakrishna Dulla E. Sailaja Upendar Reddy CH Madhu Aeluri Arunasree M. Kalle S. Bhavani D. Rambabu M.V. Basaveswara Rao Manojit Pal 《Tetrahedron letters》2014
Indole based novel small molecules were designed as potential anticancer agents. Multi step synthesis of these compounds was carried out by using Pd/C–Cu mediated coupling–cyclization strategy as a key step. The single crystal X-ray diffraction study was used to confirm the molecular structure of a representative compound unambiguously. Many of these compounds were evaluated for their anti-proliferative properties in vitro against six cancer cell lines as well as noncancerous cells. All these compounds showed selective growth inhibition of cancer cells and several of them were found to be promising with IC50 values in the range of 0.1–1.2 μM, comparable to the known anticancer drug doxorubicin. 相似文献
64.
65.
Resonance absorption, the reabsorption of laser light by the laser transition of the dopant material itself, is found to be the limiting factor for fibre lasers when extremely long fibres are used. We report on measurements of the temperature dependence of the losses in a 8.5 m long commercial Nd3+ doped fibre (York, ND 95020/E). To determine the reabsorption losses, the threshold power has been measured as a function of temperature between 243 K and 413 K. The results are compared with theory assuming a 4l
level energy of 2110 cm-1 and an absorption cross-section of δ = 1.15 x 10-20cm2. The comparison shows that reabsorption from the thermally populated 4l
level is the dominant contribution to the measured losses. 相似文献
66.
The radiative strength functions for the partial γ-transitions from neutron resonances to the ground and low-lying states of odd-A spherical nuclei are calculated within the quasiparticle-phonon nuclear model. The fragmentation of one-quasiparticle and quasiparticle-plus-phonon states is calculated. This allowed one to calculate γ-transitions between the one-quasi-particle components (valence transitions) and γ-transitions between the quasiparticle-plus-phonon and one-quasiparticle components of the wave functions. The energy dependence of the strength functions (E1, η) and (M1, η) is calculated near the neutron binding energy Bn for 55Fe and 59, 61Ni. The corresponding experimental data are described qualitatively. The contribution of the valence E1 transitions to the strength function is shown to be from 20% to 90%, and M1 transitions about 1%. The influence of the M1 giant resonance is important for M1 transition probabilities. 相似文献
67.
Co(II), Ni(II), Mn(II), Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, Ti(IV), V(IV), Zr, Hf, Th, Al, Sc, Y, La, the lanthanides and also U(VI), which accompany copper(II) in hydrochloric acid-acetone mixtures, can be separated from copper by eluting copper(II) with 0.50 M hydrobromic acid in 85% acetone from a column of AG 50W-X8 resin, 200–400 mesh, while all these elements are retained by the column quantitatively. Separations are sharp and quantitative, as is demonstrated by results for some synthetic mixtures. Some relevant elution curves are presented. 相似文献
68.
69.
Magnetism and hyperfine fields at transition metal surfaces are discussed using state-of-the-art local spin density methods.
Emphasis is placed on recent results obtained for the Fe(001), Ni(001), Cr(001) and Ag/Fe(001) ferromagnetic surfaces, and
for the Knight shift in Pt(001). 相似文献
70.
Wetherby AE Goeller LR DiPasquale AG Rheingold AL Weinert CS 《Inorganic chemistry》2007,46(18):7579-7586
The protonolysis reaction of the germanium(II) amide Ge[N(SiMe3)2]2 with calix[4]arene and calix[8]arene furnishes the two germanium(II) calixarene complexes {calix[4]}Ge2 and {calix[8]}Ge4, respectively, which have been crystallographically characterized. The calix[4]arene complex contains a Ge2O2 rhombus at the center of the molecule and is one of the only four germanium(II) calix[4]arenes that have been structurally characterized. The calix[8]arene species is the first reported germanium calix[8]arene complex, and it exhibits an overall bowl-shaped structure which contains two Ge2O2 fragments. The latter complex reacts with Fe2(CO)9 to yield an octairon compound, which has also been structurally characterized and contains four GeFe2 triangles arranged around the macrocyclic ring. The germanium(II) centers are oxidized to germanium(IV) in this process, with concomitant reduction of the neutral diiron species to Fe2(CO)(8)2- anions. 相似文献