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排序方式: 共有171条查询结果,搜索用时 15 毫秒
161.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2875–2876, December, 1990. 相似文献
162.
K. G. Grigorov G. I. Grigorov M. Stoyanova J. L. Vignes J. P. Langeron P. Denjean J. Perriere 《Applied Physics A: Materials Science & Processing》1992,55(5):502-504
Two kinds of reactively evaporated titanium nitride films with columnar (B
0 films) and fine-grained film structure (B
+ films) have been examined as diffusion barriers, preventing the silicon diffusion in silicon devices. The silicon diffusion profiles have been investigated by 2 MeV 4He+ Rutherford backscattering spectrometry (RBS) after annealing at temperatures up to 900° C, in view of application of high-temperature processes. The diffusivity from 400 to 900° C: D (m2 s–1)=2.5×10–18 exp[–31 kJ/mol/(RT)] in B
0 layers and D (m2 s–1)=3×10–19 exp[–26 kJ/mol/(RT) in B
+ TiN layers. The diffusivities determined correspond to grain boundary diffusion, the difference being due to the different microstructure. The very low diffusivity of silicon in B
+ TiN layer makes it an excellent high-temperature barrier preventing silicon diffusion. 相似文献
163.
Song XF Sosebee M Sotnikova N Souza M Stanton NR Steinbruck G Stephens RW Stevenson ML Stichelbaut F Stoker D Stolin V Stoyanova DA Strauss M Streets K Strovink M Stutte L Sznajder A Tamburello P Tarazi J Tartaglia M Thomas TL Thompson J Toback D Trippe TG Turcot AS Tuts PM 《Physical review letters》2000,84(2):222-227
We report a measurement of the W boson mass based on an integrated luminosity of 82 pb(-1) from p&pmacr; collisions at sqrt[s] = 1.8 TeV recorded in 1994-1995 by the D0 detector at the Fermilab Tevatron. We identify W bosons by their decays to enu, where the electron is detected in the forward calorimeters. We extract the mass by fitting the transverse mass and the electron and neutrino transverse momentum spectra of 11 089 W boson candidates. We measure M(W) = 80.691+/-0.227 GeV. By combining this measurement with our previously published central calorimeter results from data taken in 1992-1993 and 1994-1995, we obtain M(W) = 80.482+/-0.091 GeV. 相似文献
164.
Smith RP Snihur R Snow GR Snow J Snyder S Solomon J Song XF Sosebee M Sotnikova N Souza M Stanton NR Steinbruck G Stephens RW Stevenson ML Stichelbaut F Stoker D Stolin V Stoyanova DA Strauss M Streets K Strovink M Sznajder A Tamburello P Tarazi J Tartaglia M Thomas TL 《Physical review letters》2000,84(24):5478-5483
This Letter describes a measurement of the muon cross section originating from b-quark decay in the forward rapidity range 2.4<| y(&mgr;)|<3.2 in p&pmacr; collisions at sqrt[s] = 1.8 TeV. The data used in this analysis were collected by the D0 experiment at the Fermilab Tevatron. We find that next-to-leading-order QCD calculations underestimate b-quark production by a factor of 4 in the forward rapidity region. 相似文献
165.
Stoyanova R Barra AL Yoncheva M Kuzmanova E Zhecheva E 《Dalton transactions (Cambridge, England : 2003)》2011,40(36):9106-9115
The zero-field splitting parameters (ZFS) of Mn(4+) and Fe(3+) ions in LiAlO(2) with a layered structure are analyzed experimentally and theoretically by using high-frequency electron paramagnetic resonance spectroscopy, Neuman superposition model (NSM), DFT and multiconfigurational calculations. The interpretation of ZFS is based on the comparison of the experimentally determined values with the calculated ones. This approach allows assessing the performance of different methods for computation of ZFS of Fe(3+) and Mn(4+) in layered oxide matrices. DFT and multiconfigurational calculations are used to analyze the effect of oxygen, aluminium, and lithium neighbours on ZFS of Fe(3+) and Mn(4+). These calculations are based on a cluster comprising Fe(3+) or Mn(4+) ions in a trigonally compressed octahedron with 6 metal ions (Al(3+) or Co(3+)) as first metal neighbours and 6 O(2-) and 2 Li(+) (above and below the layer) as second neighbours. A satisfactory agreement with the experimental data is achieved when the local structure of Mn(4+) and Fe(3+) deviates from the trigonal host-site geometry. The local structure of Fe(3+) comprises an axial distortion, while trigonal environment with reduced extent of distortion appears around Mn(4+). 相似文献
166.
Wanner J Bail S Jirovetz L Buchbauer G Schmidt E Gochev V Girova T Atanasova T Stoyanova A 《Natural product communications》2010,5(9):1355-1358
Cumin oil samples (Cuminum cyminum L.) from four different geographical origins were analyzed using GC-MS and GC-FID for their qualitative and quantitative composition. The major compounds in all cumin oils were the monoterpenes beta-pinene, p-cymene and gamma-terpinene and the terpenoid aldehydes cuminic aldehyde and the isomeric menthadien carboxaldehydes. All essential oils, and cuminic aldehyde, were tested, using agar diffusion and serial dilution methods, against different Gram-positive and Gram-negative bacteria isolated from different sources of food (pork fillet, minced meat and sausages) and clinical isolates, as well as three different Candida albicans isolates. All cumin oils and cuminic aldehyde exhibited a considerable inhibitory effect against all the organisms tested, except Pseudomonas spp. 相似文献
167.
Stoyanov ES Stoyanova IV Tham FS Reed CA 《Journal of the American Chemical Society》2008,130(36):12128-12138
The nature of H(H2O)n(+) cations for n = 3-8 with weakly basic carborane counterions has been studied by IR spectroscopy in benzene and dichloroethane solution. Contrary to general expectation, neither Eigen-type H3O x 3 H2O(+) nor Zundel-type H5O2(+) x 4 H2O ions are present. Rather, the core species is the H7O3(+) ion. 相似文献
168.
We apply polynomial techniques to investigate the structure of spherical designs in an asymptotic process with fixed odd strength while the dimension and odd cardinality tend to infinity in a certain relation. Our bounds for the extreme inner products of special points in such designs allow new lower bounds on the minimum possible odd cardinality. 相似文献
169.
170.
Pantcheva Ivayla N. Stambolyiska Radoslava D. Petkov Nikolay N. Tadjer Alia V. Simova Svetlana D. Stoyanova Radostina K. Kukeva Rositza R. Dorkov Petar D. 《Transition Metal Chemistry》2022,47(1):67-76
Transition Metal Chemistry - The 16-membered macrolide antibiotics tylosin (HTyl) and tilmicosin (HTilm) react with Cu(II) to form isostructural mononuclear complexes of composition [CuL2]... 相似文献