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971.
G. Medeiros-Ribeiro A. Malachias S. Kycia R. Magalhães-Paniago T.I. Kamins R. Stanley Williams 《Applied Physics A: Materials Science & Processing》2005,80(6):1211-1214
Self-assembled nanocrystals grown by epitaxy represent a viable way to mass produce quantum structures exhibiting novel electronic properties. In order to infer the electronic properties of such systems, knowledge of both composition and strain is necessary. Here, detailed maps of these quantities were obtained by anomalous X-ray diffraction for samples grown at 600 °C and 700 °C by chemical vapor deposition and molecular beam epitaxy, respectively – two different temperatures and growth techniques. From these maps, the elastic energies stored in the islands were evaluated. It was found that the elastic energy is concentrated at the island borders, regardless of the growth temperature or method. In contrast, the regions with the lowest elastic energy were the island core and top. These results provide insight into the mechanisms that govern the growth and evolution of strained nanocrystals. PACS 71.35.Ji; 78.67.Hc; 73.22.Dj 相似文献
972.
Travis Williams 《电子设计技术》2004,11(10)
鉴于USB(通用串行总线)ASIC控制器的线宽不断变小,迫使物理层从控制器中分离出来,这使得许多系统设计人员认识到物理层独立的重要性.由于业界所需的分立物理层器件能与在较低VCC下工作的USB控制器接口,系统设计人员必须在符合USB2.0标准的系统中正确地引进物理层. 相似文献
973.
晶圆表面如果有一层薄且均匀的流体边界层,将有助于克服光刻图形带来的挑战,得到更均匀的金属沉积层。 相似文献
974.
Durlam M. Naji P.J. Omair A. DeHerrera M. Calder J. Slaughter J.M. Engel B.N. Rizzo N.D. Grynkewich G. Butcher B. Tracy C. Smith K. Kyler K.W. Ren J.J. Molla J.A. Feil W.A. Williams R.G. Tehrani S. 《Solid-State Circuits, IEEE Journal of》2003,38(5):769-773
A low-power 1-Mb magnetoresistive random access memory (MRAM) based on a one-transistor and one-magnetic tunnel junction (1T1MTJ) bit cell is demonstrated. This is the largest MRAM memory demonstration to date. In this circuit, the magnetic tunnel junction (MTJ) elements are integrated with CMOS using copper interconnect technology. The copper interconnects are cladded with a high-permeability layer which is used to focus magnetic flux generated by current flowing through the lines toward the MTJ devices and reduce the power needed for programming. The 25-mm/sup 2/ 1-Mb MRAM circuit operates with address access times of less than 50 ns, consuming 24 mW at 3.0 V and 20 MHz. The 1-Mb MRAM circuit is fabricated in a 0.6-/spl mu/m CMOS process utilizing five layers of metal and two layers of poly. 相似文献
975.
Gregory G Wildgoose Shelley J Wilkins Gareth R Williams Robert R France David L Carnahan Li Jiang Timothy G J Jones Richard G Compton 《Chemphyschem》2005,6(2):352-362
We demonstrate that graphite powder and multiwalled carbon nanotubes (MWCNTs) can be derivatised by 4-nitrobenzylamine (4-NBA) simply by stirring the graphite powder or MWCNTs in a solution of acetonitrile containing 10 mM 4-NBA. We propose that 4-NBA partially intercalates at localised edge-plane or edge-plane-like defect sites and this hypothesis with a range of experimental data provided by electrochemistry in both aqueous and nonaqueous media, electron microscopy and X-ray powder diffraction. 相似文献
976.
977.
A. Butera M. Vsquez Mansilla A. Fainstein G. V. M. Williams 《Physica B: Condensed Matter》2002,320(1-4):316-318
We have made high-temperature (250 K<T<800 K) DC susceptibility measurements in the compounds RuSr2Eu2−xCexCu2O10 for x=0.6,0.8, and 1.0 in order to determine the Ru effective magnetic moment. After carefully subtracting all contributions to the magnetic susceptibility except that of the Ru ions, we have been able to fit the Ru susceptibility with a law χRu=χ0+CRu/(T−ΘRu). We have found that the Ru effective moment
falls between the values expected for Ru5+ in spin states
and
. We have also found a dependence of μeff(Ru) and ΘRu with the Ce content x. 相似文献
978.
A new class of time-frequency distribution (TFD) kernels is introduced. Members in this class satisfy the desirable TFD properties and simultaneously provide local autocorrelation functions (LAF) that are amenable to high-frequency resolution modeling techniques. It is shown that members of the proposed class are product kernels, fast implementation multiplication-free kernels, recursive kernels, and optimum kernels with respect to autoterm localization 相似文献
979.
IfPis an irreducible element of a polynomial ring over a finite field, then one can define a Fermat quotient function associated toP. This is the direct analog of the traditional Fermat quotient function defined over the rational numbers using Fermat's “little” theorem. This paper provides answers for several of the central questions about the Fermat quotients over function fields. 相似文献
980.
Jim Harrison 《今日电子》2005,(9):34-34
美国一家小公司gumstix开发了只有口香糖大小的基于200 MHz和400MHz Inter XScale PXA255处理器的微型计算机。这是一款开放源码的硬件设备,所有图表和数据都可在该公司的网站上免费获得。 相似文献