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排序方式: 共有299条查询结果,搜索用时 31 毫秒
21.
Mechanical stress in damascene copper/low-k interconnects has been studied by means of micro-rotating sensors embedded in chips and directly integrated in CMOS process flow. A new hinge sensor design has been elaborated and a new analytical model of the mechanical equilibrium of sensors is validated. These sensors allow the study of the average residual stress as a function of the line width in a range from few hundred nanometers to several microns. It was found that the residual stress increases from 290 to 850 MPa in, respectively, 2 and 0.25 μm wide lines. This trend shows a yield stress increase with the line width reduction. Copper grains microstructure change between large and narrow lines is probably one of the reasons for yield stress and so residual stress increase. This microstructure change has been observed by means of Transmission Electron Microscopy (TEM) observations. 相似文献
22.
Guadalupe Valverde-Aguilar Jorge A. García-Macedo Víctor M. Rentería-Tapia Raúl W. Gómez Manuel Quintana-García 《Journal of nanoparticle research》2011,13(10):4613-4622
Hexagonal mesostructured films containing silver ions were obtained by sol–gel method. Brij 58 was used to produce channels
into the film, which house these ions. The films were exposure to UV radiation to produced silver metallic nanoparticles.
The presence of the metallic nanoparticles was determined by infrared spectroscopy and optical absorption. Besides, these
nanoparticles and core–shell structures of silver–silver oxide nanoparticles were identified by high-resolution transmission
electronic microscopy. From these measurements, the obtained size range for silver nanoparticles was 6.1 nm. The absorption
spectrum located at 440 nm was modelled and well fitted with the Gans theory considering refractive index higher than the
one coming from host matrix. This index is explained because the silver oxide shell modifies the local surrounding medium
of the metallic nanoparticles. 相似文献
23.
Sandra Cruz Sylvain Bernès Pankaj Sharma Rosa Vazquez Guadalupe Hernández Roberto Portillo René Gutiérrez 《应用有机金属化学》2010,24(1):8-11
Optically pure α‐diimines quantitatively obtained in solvent‐free conditions starting from 2,3‐butanedione and (S)‐(?)‐1‐phenylethylamine and (S)‐(?)‐1‐(4‐methylphenyl)ethylamine, respectively, yielded the new chiral mono‐Pd complexes 2a–b, which have been partly characterized by IR, 1H‐ and 13C‐NMR spectroscopies along with MS‐FAB+ spectrometry. The crystal and molecular structure for palladacycle 2a has been fully confirmed by single‐crystal X‐ray studies. Studies in vitro of 2a–b have displayed growth inhibition against different classes of cancer: leukemia (K‐562 CML), colon cancer (HCT‐15), breast cancer (MCF‐7), central nervous system (U‐251 Glio) and prostate cancer (PC‐3) cell lines. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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25.
Guadalupe Silvero Martín ÁvalosReyes Babiano Pedro CintasJosé L. Jiménez Juan C. Palacios 《Tetrahedron》2011,67(40):7811-7820
Through a well-established enzymatic transformation glucosinolates release reactive isothiocyanates that can undergo further metabolic pathways affording a plethora of reactive metabolites. This study explores in detail the reaction of benzyl isothiocyanate, which possesses antitumor activity as alkylating agent, with d-glucosamine, commonly employed in oral treatments against osteoarthritis and inflammation. Structures of the resulting products and their evolution have been assessed and compared with those involving d-glucose, reported previously. Chemical results suggest that clinical treatments with d-glucosamine could reduce the beneficial effects associated with diets based on glucosinolate-rich foods. 相似文献
26.
Tomás Caraballo Alexandre N. CarvalhoJosé A. Langa Felipe Rivero 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(6):2272-2283
In this paper we consider the strongly damped wave equation with time-dependent terms
utt−Δu−γ(t)Δut+βε(t)ut=f(u), 相似文献
27.
The electronic structure of HgBa(2)Ca(n) (-1)Cu(n)O(2n+2) (n = 1, 2, and 3) high T(c) superconductor parent compounds has been investigated by means of periodic hybrid density functional theory. Similar to other cuprates, these materials are predicted to exhibit an antiferromagnetic ground state with well localized S = 1/2 magnetic centers at the Cu(2+) sites. However, the presence of the HgO(2) structural units largely defines the nature of states dominating the energy range around Fermi energy. This results in a complex charge transfer character of the insulating gap which decreases when increasing the number of CuO(2) planes in the unit cell, to the point that in the HgBa(2)Ca(2)Cu(3)O(8) compound it becomes so small that one can claim that the resulting material is metallic. Nevertheless, the metallic character arises from the HgO(2) structural units and coexists with the antiferromagnetic order arising from the localized spins at the Cu(2+) sites. 相似文献
28.
Gregory L AdamsTodd L Graybill Robert M SanchezVictoria W Magaard George BurtonRalph A Rivero 《Tetrahedron letters》2003,44(27):5041-5045
A robust ‘catch and release’ synthesis of fused 2-alkylthio-3-substituted-pyrimidinones mediated by the polymer-bound base P-BEMP is described. This reengineered synthesis combines the efficiency of the classical synthesis (three steps, three diversity points) with the practical benefits of resin-bound reagents. The solution-phase strategy, reagent compatibility, and the results of a representative 48-member combinatorial library are described and presented herein. 相似文献
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