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排序方式: 共有459条查询结果,搜索用时 15 毫秒
21.
A. D. Chernyshov V. V. Goryainov A. N. Marchenko 《Thermophysics and Aeromechanics》2016,23(2):237-245
The approximate analytic solution of the problem of temperature field in a rectangular plate with an internal temperature- dependent source is obtained by the method of fast expansions. The critical value of a parameter characterizing heat release, which fundamentally affects the analytic solution form, is found. The maximum solution error is shown to amount to 0.02 at the consideration of the first three terms of the Fourier series in fast expansion. Temperature fields are presented, and an analysis of the influence of the plate sizes and the heat release magnitude on their formation is given. Recommendations on the plate shape choice are given. 相似文献
22.
V. A. Marchenko 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(7):867-870
Experimental realization of the hysteresis-free mode of vanadium reactive magnetron sputtering in Ar-O2 mixtures made it possible to perform detailed measurements of the discharge current-voltage characteristics for the first time. They appeared to be not smooth, as predicted by the existing model of reactive sputtering, but having a kink. The experimental data can be interpreted on the assumption that the target surface is oxidized at a depth not less than two monolayers at low ion current densities. 相似文献
23.
R.V. Ryabova Yu.A. Bykovsky V.A. Elkhov A.I. Larkin V.L. Potapov L.N. Gnatiuk M.L. Gurari S.N. Marchenko 《Optics Communications》1976,18(3):406-409
New photographic materials for recording the radiation of injection lasers (λ=840 nm) with a sensitivity of ?10-4 J/sm2 and a resolution of 4300 lines/mm, and photographic materials for recording the radiation in the region of 1060 nm with a sensitivity of ?10-4 J/sm2 and a resolution of 1000 lines/mm are described. 相似文献
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25.
Marchenko AV Vedernikov AN Dye DF Pink M Zaleski JM Caulton KG 《Inorganic chemistry》2004,43(1):351-360
The reaction of equimolar NO with the 16 electron molecule RuHCl(CO)L(2) (L = P(i)Pr(3)) proceeds, via a radical adduct RuHCl(CO)(NO) L(2), onward to form RuCl(NO)(CO)L(2) (X-ray structure determination) and RuHCl(HNO)(CO)L(2), in a 1:1 mole ratio. The HNO ligand, bound by N and trans to hydride, is rapidly degraded by excess NO. The osmium complex behaves analogously, but the adduct has a higher formation constant, permitting determination of its IR spectrum; both MHCl(CO)(NO)L(2) radicals are characterized by EPR spectroscopy, and DFT calculations on the Ru system show it to have a "half-bent" Ru-N-O unit with the spin density mainly on nitrogen. DFT (PBE) energies rule out certain possible mechanistic steps for forming the two products. A survey of the literature leads to the hypothesis that NO should generally be considered as a (neutral) Lewis base (2-electron donor) when it binds to a 16 electron complex which is resistant to oxidation or reduction, and that the resulting N-centered radical has a M-N-O angle of approximately 140 degrees, which distinguishes it from NO(-) (bent at <140 degrees ) and from NO(+) (>170 degrees ). 相似文献
26.
Brener EA Marchenko VI Muller-Krumbhaar H Spatschek R 《Physical review letters》2000,84(21):4914-4917
We discuss the coarsening process of melt inclusions inside a solid phase. Elastic effects lead to an oblate shape of the particles, resulting in a system with strong diffusional and elastic interactions between inclusions. The usual mean-field approximation breaks down and several independent length scales have to be taken into account. In a system of parallel oriented particles we find scaling laws for the coarsening of the different length scales involved. In particular, the lateral size of the particles obeys a nontrivial growth law, R approximately t(5/12). 相似文献
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28.
Reversible Modulation of Surface Plasmons in Gold Nanoparticles Enabled by Surface Redox Chemistry 下载免费PDF全文
Dr. Zheng Li Dr. Jonathan J. Foley IV Dr. Sheng Peng Dr. Cheng‐Jun Sun Dr. Yang Ren Dr. Gary P. Wiederrecht Dr. Stephen K. Gray Dr. Yugang Sun 《Angewandte Chemie (International ed. in English)》2015,54(31):8948-8951
Switchable surface redox chemistry is demonstrated in gold@iron/iron oxide core–shell nanoparticles with ambient oxidation and plasmon‐mediated reduction to modulate the oxidation state of shell layers. The iron shell can be oxidized to iron oxide through ambient oxidation, leading to an enhancement and red‐shift of the gold surface plasmon resonance (SPR). This enhanced gold SPR can drive reduction of the iron oxide shell under broadband illumination to reversibly blue‐shift and significantly dampen gold SPR absorption. The observed phenomena provide a unique mechanism for controlling the plasmonic properties and surface chemistry of small metal nanoparticles. 相似文献
29.
Richard P. Kent IV 《Geometriae Dedicata》2004,106(1):145-159
We answer a question of J. Anderson's by producing infinitely many commensurability classes of fibered hyperbolic 3-manifolds whose fundamental groups contain subgroups that are locally free and not free. These manifolds are obtained by performing 0–surgery on a collection of knots with the same properties. 相似文献
30.
Nucleation and Growth Synthesis of Siloxane Gels to Form Functional,Monodisperse, and Acoustically Programmable Particles 下载免费PDF全文
C. Wyatt Shields IV Danping Sun Dr. Kennita A. Johnson Korine A. Duval Aura V. Rodriguez Dr. Lu Gao Prof. Paul A. Dayton Prof. Gabriel P. López 《Angewandte Chemie (International ed. in English)》2014,53(31):8070-8073
Nucleation and growth methods offer scalable means of synthesizing colloidal particles with precisely specified size for applications in chemical research, industry, and medicine. These methods have been used to prepare a class of silicone gel particles that display a range of programmable properties and narrow size distributions. The acoustic contrast factor of these particles in water is estimated and can be tuned such that the particles undergo acoustophoresis to either the pressure nodes or antinodes of acoustic standing waves. These particles can be synthesized to display surface functional groups that can be covalently modified for a range of bioanalytical and acoustophoretic sorting applications. 相似文献