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排序方式: 共有389条查询结果,搜索用时 46 毫秒
1.
2.
Beyene W.T. Xingchao Yuan Cheng N. Hao Shi 《Advanced Packaging, IEEE Transactions on》2004,27(1):34-44
With the rapid advance of silicon process technology, it is now possible to design input/output (I/O) circuits that operate at multigigabit data rates. As a result, accurate modeling and analysis of high-speed interconnect systems is essential to optimize the performance of the overall system. This paper describes the interconnect design, modeling, simulation, and characterization methodologies that are essential to achieve multigigabit data rates. It focuses on the physical layer verification and hardware correlation of functional systems and silicon to ensure robust system operation over 3.2Gb/s data rate using conventional low-cost packaging and printed circuit board (PCB) technologies. In order to capture conductor and dielectric losses, as well as other high-frequency effects of three-dimensional structures, accurate measurement-based simulation techniques that directly incorporate frequency-domain parameters from measurement or electromagnetic solver parameters into circuit simulation tools using fast Fourier transform (FFT) and bandlimiting windowing techniques are developed. Finally, simulation waveforms are correlated with prototypes at both component and system levels in both time and frequency domains. 相似文献
3.
Girma Kebbede 《Cities》1985,2(1):75-76
Fiscal disparities between US central cities and their suburban communities have long been recognized. Many older medium-sized and large cities in the North-eastern and North-central regions of the USA are suffering from a continuous decline in their tax bases. Governments of aging central cities have lost much of their tax base to the expanding suburban jurisdictions and are unable to generate the revenue needed to meet the growing public service demands placed upon them. 相似文献
4.
Zhang Hongtao Cai Minghui Zhu Wanjun Sun Shenghui Yan Haile Yao Shengjie Luan Yikun Tang Shuai Hodgson P. D. 《Metallurgical and Materials Transactions A》2022,53(11):3869-3880
Metallurgical and Materials Transactions A - A cold-rolled low Al-added medium Mn steel was employed to investigate the low-temperature superplastic deformation at a relatively high initial strain... 相似文献
5.
Todd?L.?KurthEmail author Girma?Biresaw Atanu?Adhvaryu 《Journal of the American Oil Chemists' Society》2005,82(4):293-299
The frictional behaviors of methyl oleate (MO), methyl palmitate (MP), methyl laurate (ML), and methyl stearate (MSt) as additives
in hexadecane have been examined in a boundary lubrication test regime using steel contacts. It was found that the transient
attributes of coefficient of friction (COF)-time spectra are a sensitive measure of adsorption equilibria. Critical additive
concentrations were defined and used to perform novel and simple Langmuir analyses that provide an order of adsoprtion energies:
MSt>MP>MO≥ML. Application of Langmuir, Temkin, and Frumkin-Fowler-Guggenheim adsorption models via nonlinear fitting of a general cooperative model demonstrates the necessary inclusion of cooperative effects in the applied
model. In agreement with the qualitative features of steady-state COF-concentration plots, MSt modeling requires minimal cooperative
interaction terms. However, MO, MP, and ML data require large attractive interaction terms to be adequately fitted. Primary
adsorption energies calculated via the cooperative model are necessarily decreased, whereas total adsorption energies correlate well with values obtained via critical concentration analyses. These results and comparisons with previous adsorption studies of MO and MSt suggest that
primary (ester-surface) and secondary (alkyl-surface) adsorbate-adsorbent, adsorbate-adsorbare, and (free-additive) adsorpt-adsorpt
interactions collectively determine both the calculated primary and the cooperative interaction energies. 相似文献
6.
Abdellatif Mohamed Mila P. Hojilla-Evangelista Steve C. Peterson Girma Biresaw 《Journal of the American Oil Chemists' Society》2007,84(3):281-288
Barley protein isolate (BPI) was extracted in 0.015 N NaOH in a 10:1 ratio solvent:flour and was precipitated by adjusting
the pH to 4.5 and freeze-dried. The thermal properties of BPI were determined using modulated differential scanning calorimetry
(MDSC). BPI with 4% moisture content exhibited a glass transition (T
g) with 140 °C onset, 153 °C middle, and 165 °C end temperatures and a ΔC
p of 0.454 J/g per °C. The high moisture content sample (50%) showed a T
g at 89, 91, or 94 °C and 0.067 ΔC
p. Acetylation had no apparent effect on the foaming and emulsifying properties of protein from barley flour but exhibited
the least-stable foam among BPI samples. Foaming capacities of both barley protein isolates were ∼12% less than that of acid-precipitated
soy protein isolate reported in the literature. Acetylated BPI showed the highest surface hydrophobicity compared to the other
samples. The surface-tension test confirmed that unmodified and modified BPI possessed surface activity. BPI phosphorous oxycloride-crosslinked
was the most effective in lowering the surface tension of aqueous NaCl, while the crosslinked BPI was the least effective.
The G′ value of BPI suspension was greater than G″ at all frequencies from 0.1 to 100 rad/s. The strain value at which linear behavior ceased and nonlinear behavior began
ranged from 3 to 10%.
Names are necessary to report factually on available data; however, the United States Department of Agriculture (USDA) neither
guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product
to the exclusion of others that may also be suitable. 相似文献
7.
Fuerhacker M Haile TM Kogelnig D Stojanovic A Keppler B 《Water science and technology》2012,65(10):1765-1773
This paper presents the results of adsorption studies on the removal of heavy metals (Cr, Cu, Cd, Ni, Pb and Zn) from standard solutions, real wastewater samples and activated sewage sludge using a new technique of liquid-liquid extraction using quaternary ammonium and phosphonium ionic liquids (ILs). Batch sorption experiments were conducted using the ILs [PR4][TS], [PR4][MTBA], [A336][TS] and [A336][MTBA]. Removal of these heavy metals from standard solutions were not effective, however removal of heavy metals from the industrial effluents/wastewater treatment plants were satisfactory, indicating that the removal depends mainly on the composition of the wastewater and cannot be predicted with standard solutions. Removal of heavy metals from activated sludge proved to be more successful than conventional methods such as incineration, acid extraction, thermal treatment, etc. For the heavy metals Cu, Ni and Zn, ≥90% removal was achieved. 相似文献
8.
Characterization and microstructure of highly preferred oriented lead barium titanate thin films on MgO (100) by sol-gel process 总被引:1,自引:0,他引:1
Highly preferred oriented lead barium titanate (Pb1−x,Bax)TiO3 thin film, with particular emphasis on (Pb0.5,Ba0.5)TiO3, can be obtained by spin-coating on MgO (100) substrate by using the precursor sol, which was synthesized from acetylacetone chelating with titanium isopropoxide and ethylene glycol as a solvent, in the sol-gel process. Film thickness, pyrolysis temperature and heating rate were studied systemically to investigate their influences on the formation of preferred oriented thin films. The highly preferred (001)/(100) oriented thin film could be obtained by the pyrolysis of wet film at 500 °C and annealing at 600 °C at a slow heating rate of 5 °C/min. It is confirmed that the tetragonal perovskite structure of the titanate ceramic decreases with an increase of Ba content in (Pb1−x,Bax)TiO3. The (001)/(100) oriented films were synthesized from all compositions between x = 0.2 and x = 0.8, at a crystallization temperature of 600 °C. In particular, for the Ba content in the range of x = 0.50.6, highly preferred (001)/(100) planes were observed. 相似文献
9.
Jinling Fan Wenxue Zhu Huaibin Kang Haile Ma Guanjun Tao 《Journal of Functional Foods》2012,4(1):147-157
Flavonoid components in flowers of 48 Zhongyuan tree penoy cultivars were identified by means of a hyphenated technique of HPLC coupled with a photodiode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESIMS). The total phenolic content (TPC) was determined by Folin–Ciocalteu method and the antioxidant activity with both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. About 14 flavonoids including five anthocyanins, three flavonol glycosides and six flavone glycosides were described. Apigenin-pento-hexoside and Apigenin-hexo-glucuronide were reported for the first time. TPC, expressed as gallic acid content, varied between 3.97 and 21.73 mg/g fresh weight. Antioxidant activity varied among the cultivars (7.66–31.36 and 4.80–17.87 mg ascorbic acid equivalents/g fresh weight for DPPH and FRAP assays, respectively) and highly corresponded with TPC. 相似文献
10.
Grigor B. Bantchev Girma Biresaw 《Journal of the American Oil Chemists' Society》2012,89(12):2227-2235
The viscosity, density, and elastohydrodynamic film thicknesses of oil-soluble polyalkyl glycols (PAG), high oleic sunflower oil (HOSuO), and their 50/50 (wt.%) blends were investigated. The viscosity and density of the blends were found to be predictable from the corresponding neat oil properties using simple mixing rules. Pressure–viscosity coefficients (PVC) of HOSuO, the two PAGs, and the two 50?wt% HOSuO/50?wt% PAG blends were calculated from measured film thickness data using the Hamrock-Dowson method and compared to values estimated from literature data. Literature pressure-density and viscosity-temperature data for oils with high-oleic acid group content were analyzed using the Tait and Casalini et al. models. Viscosity versus pressure data obtained from these analyses was used to calculate PVC using the Barus and Bair et al. models. The PVC values calculated from the literature data following this procedure showed reasonable agreement with that from film thickness data from this work. 相似文献