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排序方式: 共有366条查询结果,搜索用时 328 毫秒
31.
Wei-lun Hung Yuan Xie Narayanan Vijaykrishnan Mahmut Kandemir Mary Jane Irwin 《Journal of Signal Processing Systems》2010,58(2):145-160
Power consumption is a top priority in high performance circuit design today. Many low power techniques have been proposed
to tackle the ever serious, highly pressing power consumption problem, which is composed of both dynamic and static power
in the nanometer era. The static power consumption nowadays receives even more attention than that of dynamic power consumption
when technology scales below 100 nm. In order to mitigate the aggressive power consumption, various existing low power techniques
are often used; however, they are often applied independently or combined with two or at most three different techniques together,
and that is not sufficient to address the escalating power issue. In this paper, we present a power optimization framework
for the minimization of total power consumption in combinational logic through multiple V
dd
assignment, multiple V
th
assignment, device sizing, and stack forcing, while maintaining performance requirements. These four power reduction techniques
are properly encoded into the genetic algorithm and evaluated simultaneously. The overhead imposed by the insertion of level
converters is also taken into account. The effectiveness of each power reduction mechanism is verified, as are the combinations
of different approaches. Experimental results are presented for a number of 65 nm benchmark circuits that span typical circuit
topologies, including inverter chains, SRAM decoders, multiplier, and a 32 bit carry adder. Our experiments show that the
combination of four low power techniques is the effective way to achieve low power budget. The framework is general and can
be easily extended to include other design-time low power techniques, such as multiple gate length or multiple gate oxide
thickness. 相似文献
32.
33.
Ali Erdoğmuş Mahmut Durmuş Ahmet Lütfi Uğur Oğuzhan Avciata Ulvi Avciata Tebello Nyokong 《Synthetic Metals》2010,160(17-18):1868-1876
The synthesis, photophysical and photochemical properties of soluble 3,4-(methylendioxy)-phenoxy substituted oxo-titanium(IV) phthalocyanines (4–6) are reported for the first time. The new compounds have been characterized by elemental analysis, FT-IR, 1H NMR spectroscopy, electronic spectroscopy and mass spectra. General trends are described for fluorescence lifetimes and fluorescence, photodegradation and singlet oxygen quantum yields, of these compounds in dimethylsulfoxide (DMSO) and toluene. The effects of the position of the substituents and solvent effect on the photophysical and photochemical parameters of the oxo-titanium(IV) phthalocyanines (4–6) are also reported. The fluorescence of the substituted oxo-titanium(IV) phthalocyanine complexes (4–6) is effectively quenched by 1,4-benzoquinone (BQ) in both DMSO and toluene. 相似文献
34.
Blom M.T. Tas N.R. Pandraud G. Chmela E. Gardeniers J.G.E. Tijssen R. Elwenspoek M. van den Berg A. 《Journal of microelectromechanical systems》2001,10(1):158-164
MicrochanneIs were created by fusion bonding of a Pyrex cover to a thermally oxidized silicon wafer, which contained anisotropically etched grooves. Such channels are frequently used in microfluidic handling systems, for example, in chemical analysis. Since in some of these labs-on-a-chip, in particular those used in liquid chromatography, the channels are subjected to high pressures of up to a few hundred bar, it is important to have information about the mechanical stability of the channel chip, in particular of the wafer bond involved in it. The latter is the subject of this paper. The maximum pressure that can be applied to several different channel chips was investigated experimentally. In order to find the relation among this maximum pressure, channel geometry, materials elasticity, and bond energy, an energy model was developed that is generally applicable to all types of wafer bonds. It was shown that the model is substantiated by the experimental pressure data, from which it could be calculated that the effective bond energy increased from 0.018 to 0.19 J/m2 for an annealing temperature ranging from 310 to 470°C 相似文献
35.
Ceylan Zafer Mahmut Kus Gulsah Turkmen Haluk Dincalp Serafettin Demic Baha Kuban Yildirim Teoman Siddik Icli 《Solar Energy Materials & Solar Cells》2007,91(5):427-431
We have studied the influence of the spacer alkyl chain length of perylenemonoimide (PMI) dyes on the device performance in dye-sensitized solar cells (DSSCs). We observed that the dyes with longer and brunched alkyl chains exhibit higher efficiencies in DSSCs. In line with these statements we now report the highest efficiency obtained under standard conditions for a perylene imide derivative with PMI-DA1 that performs 300 mV open circuit voltage, 9.79 mA/cm2 short-circuit current and 1.61% overall conversion efficiency. 相似文献
36.
Experimental and theoretical analysis of particle distribution in particulate metal matrix composites 总被引:2,自引:0,他引:2
Particle distribution in particulate metal matrix composites was investigated experimentally and theoretically. SiC reinforced Pb 20%Sn alloy mechanically was stirred and cast into a cylindrical mold by an inert gas pressure. Particle distribution in the cast is determined at several locations by sectioning and microscopic investigation techniques. The particle fraction is found to decrease along the axis of the mold. The regions close to the boundary wall are determined as the possible clustering areas. A mathematical model is developed to characterize flow of mixture of molten metal alloy and ceramic particles. The distribution of particles is estimated from the trajectories of representative particles with the Lagrangian point of view. The numerical results are reasonably suited with experimental data. 相似文献
37.
38.
The 1:1 compound, CeA1O3 , in the system Ce2 O3 –Al2 O3 has been synthesized from the oxides and shown to have a perovskite-like tetragonal unit cell with the lattice parameters a = 3.763 and c = 3.792 Å. A new XRD pattern is suggested for CeA1O3 . This compound is shown to be stable up to 1950°C. The 1:11 compound, CeAl11 O18 , has also been synthesized and shown to possess a magnetoplumbite-like hexagonal unit cell with the lattice parameters α= 5.558 and c = 22.012 å. An XRD pattern is suggested for CeAl11 O18 for the first time. The evolution of eutectic-like microstructures was observed and reported in the Ce2 O3 -rich side of this binary system. 相似文献
39.
Ersin Emre Oren Ercan Taspinar A. Cuneyt Tas 《Journal of the American Ceramic Society》1997,80(10):2714-2716
Antiferroelectric PbZrO3 has been synthesized by homogeneous precipitation from aqueous solutions in the presence of urea (NH2 CONH2 ) and calcination for 6 h at 700°C. SEM studies displayed the presence of submicrometer powder, with a significant degree of agglomeration. 相似文献