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排序方式: 共有1314条查询结果,搜索用时 31 毫秒
181.
SAN DIEGO—Sony公司已经通知其经销商,称其将引进一套新的销售政策,主要针对特定的高档产品,旨在维护价值,并且帮助零售商保持盈利。 相似文献
182.
Takaaki Koyanagi Yutai Katoh Caen Ang Derek King Greg E. Hilmas William G. Fahrenholtz 《Journal of the American Ceramic Society》2019,102(1):85-89
The response of polycrystalline TiB2 to neutron irradiation was investigated. The material was fabricated using isotopically enriched 11B powders to minimize helium production via the 10B(n, α)7Li reaction. Neutron irradiation was conducted at temperatures of ~200°C and ~600°C to a fast fluence of 2.4 × 1025 n/m2 (>0.1 MeV). The material exhibited some swelling, but less swelling at the higher irradiation temperature. No macroscopic damage was observed in the irradiated material, although moderate irradiation-induced micro-cracking was found in the irradiated TiB2. This study demonstrated improved radiation resistance of isotopically tailored TiB2 compared with natural boron TiB2, which exhibited macroscopic fracture by irradiation. 相似文献
183.
Joel L. Ramirez Greg J. Zahner Kimberly A. Spaulding Sukaynah A. Khetani Nancy K. Hills Warren J. Gasper William S. Harris Beth E. Cohen S. Marlene Grenon 《Lipids》2019,54(4):211-219
Population-based data suggest that individuals who consume large dietary amounts of n-3 polyunsaturated fatty acids (PUFA) have lower odds of peripheral artery disease (PAD); however, clinical studies examining n-3 PUFA levels in patients with PAD are sparse. The objective of this study is to compare erythrocyte membrane fatty acid (FA) content between patients with PAD and controls. We conducted a cross-sectional study of 179 vascular surgery outpatients (controls, 34; PAD, 145). A blood sample was drawn and the erythrocyte FA content was assayed using capillary gas chromatography. We calculated the ratio of the n-3 PUFA eicosapentaenoic acid (EPA) to the n-6 PUFA arachidonic acid (ARA) as well as the omega-3 index (O3I), a measure of erythrocyte content of the n-3 PUFA, EPA, and docosahexaenoic acid (DHA), expressed as a percentage of total erythrocyte FA. Compared with controls, patients with PAD smoked more and were more likely to have hypertension and hyperlipidemia (p < 0.05). Patients with PAD had a lower mean O3I (5.0 ± 1.7% vs 6.0 ± 1.6%, p < 0.001) and EPA:ARA ratio (0.04 ± 0.02 vs 0.05 ± 0.05, p < 0.001), but greater mean total saturated fats (39.5 ± 2.5% vs 38.5 ± 2.6%, p = 0.01). After adjusting for several patient characteristics, comorbidities, and medications, an absolute decrease of 1% in the O3I was associated with 39% greater odds of PAD (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.03–1.86, and p = 0.03). PAD was associated with a deficiency of erythrocyte n-3 PUFA, a lower EPA:ARA ratio, and greater mean total saturated fats. These alterations in FA content may be involved in the pathogenesis or development of poor outcomes in PAD. 相似文献
184.
James D. McCambridge Myles A. Steiner Blair L. Unger Keith A. Emery Eric L. Christensen Mark W. Wanlass Allen L. Gray Laszlo Takacs Roger Buelow Timothy A. McCollum James W. Ashmead Greg R. Schmidt Alex W. Haas John R. Wilcox James Van Meter Jeffery L. Gray Duncan T. Moore Allen M. Barnett Richard J. Schwartz 《Progress in Photovoltaics: Research and Applications》2011,19(3):352-360
We have designed, fabricated, and tested a small, integrated photovoltaic module comprised of two separately‐contacted, high efficiency, multijunction solar cells and non‐imaging optics that both concentrate and spectrally split the incoming light. This hybrid design allows us to individually optimize the tandem cells and optical elements. The system has a measured module efficiency, including optical and packaging losses but not power combination losses, of 38.5 ± 1.9% under the AM1.5 direct terrestrial spectrum. The internal optics concentrate the light by a factor of approximately 20. We find excellent agreement between the modeled and measured performance. This is the highest confirmed conversion efficiency demonstrated for a photovoltaic module. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
185.
186.
Gerald S. Poplin Timothy L. McMurry Jason L. Forman Thomas Hartka Gwansik Park Greg Shaw Jangho Shin Hyung joo Kim Jeff Crandall 《Accident; analysis and prevention》2015
Injuries to the hollow organs of the lower digestive system carry substantial risk of complication due to infection and blood loss, and commonly require invasive abdominal surgery to diagnose and treat. The causes of, and risk factors for, lower abdomen injury in automobile collisions are poorly understood. The goal of this study was to investigate the risk factors and potential mechanisms of hollow-organ, lower abdomen injury in belted automobile occupants in frontal collisions. 相似文献
187.
Nima R. Alkhorshid Gregório L.S. Araujo Ennio M. Palmeira Jorge G. Zornberg 《Geotextiles and Geomembranes》2019,47(5):632-641
Stone columns have been used to minimize the settlement of embankments on soft soils but their use in very soft soils can become challenging, partly because of the low confinement provided by the surrounding soil. Geosynthetic encased columns (GECs) have been successfully used to enhance to reduce settlements of embankments on soft soils. This paper describes an investigation on the performance of encased columns constructed on a very soft soil using different types of encasement (three woven geotextiles with different values of tensile stiffness) and different column fill materials (sand, gravel and recycled construction and demolition waste, RCDW). The results of load capacity tests conducted on large-scale models constructed to simulate the different types of GECs indicate that the displacement method adopted during column installation can lead to an enhanced shear strength in the smear zone that develops within the very soft soil. In addition, breakage of the column fill material was found to affect the load-settlement response of gravel and RCDW columns. Furthermore, the excess pore water pressure generated in the surrounding soil during installation, was found to remain limited to radial distances smaller than three times the GEC diameter. 相似文献
188.
Coalification is a burial metamorphic process fundamental to understanding the origin and nature of coals and petroleum. Accurate assessment of Coalification requires removal of the variation in coal properties owing to differences in coal type. This is best achieved by assessing the coal rank of the maceral groups exinite, vitrinite and inertinite (and ultimately the macerals within each group) in terms of maximum reflectance. The mean maximum reflectances of exinite (R?E max), vitrinite (R?v max) and inertinite (R?I max) are highly correlated over the rank range, soft brown coals to low-volatile bituminous coals. A single exinite Coalification break is identified at 0.4 to 0.5% R?V max. Thereafter, exinite coalification occurs at an increasing rate (R?E max relative to R?V max) over the rank range 0.5–2.0% R?V max, crossing the vitrinite Coalification path at 1.55% R?V max. A phase of rapid inertinite Coalification (0.7–2.0% R?I max) occurs between 0.2 and 0.9% R?V max. Since exinite is a major land-plant source of hydrocarbons, and R?E max is a sensitive indicator of organic maturation over the range 0.2–1.1% R?E max, which corresponds to the main phase of oil generation, R?E max can be a most useful indicator of petroleum generation. The inertinite lnkohlungsprung represents a dramatic compositional change which should be taken into account when considering the origin of inertinite, its utilization properties and the general processes of rank change and organic maturation. 相似文献
189.
Mass budgets for total mercury, major ions and nutrients were calculated for Amituk Lake, located on Cornwallis Island, Nunavut, Canada. Total mercury in two distinct snowpacks averaged 1.25 and 4.21 ng L(-1); the discharge-weighted concentration of influent streams averaged 0.76 ng L(-1). The recent and pre-industrial Hg(T) fluxes in atmospheric deposition to the catchment were estimated to be 0.57 and 0.23 microg m(-2) but through retention within the catchment and/or re-volatilization from the melting snowpack, these decreased by 69% in the lake inflow. The spring freshet was the prime conduit for transporting Hg(T) into Amituk Lake. Because of limited mixing of surface runoff with the lake water column during snowmelt, 59% of the Hg(T) input was directly discharged through the outflow, 16% entered the lake water column where concentrations increased from 0.23 to 0.33 ng L(-1) from June to August and 25% was deposited to the bottom sediments producing a sediment Hg(T) flux of 3.1 microg m(-2). 相似文献
190.
Biofilm samples from a carbonaceous trickling filter (TF) were evaluated in bench scale reactors to determine their maximum potential denitrification rates. Intact, undisturbed biofilms were placed into 0.6 L bench-scale reactors filled with sterilized, primary clarifier effluent spiked with nitrate to a final concentration of 16-18 mg/L as N. Dissolved oxygen concentrations were maintained between 2 and 4 mg/L in the bulk aqueous phase. Nitrate loss from the reactors was monitored over a 5h period. Denitrification rates of 3.09-5.55 g-N/m(2)day were observed with no initial lag period. This suggests that the capacity for denitrification is inherent in the biofilm and that denitrification can take place even when oxygen is present in the bulk aqueous phase. There were no significant differences in denitrification rates per unit area of media (g-N/m(2)day) either between (a). experimental runs or (b). sampling locations over the trickling filter. This suggests that denitrification potentials are uniform over the entire volume of the full-scale TF. For wastewater treatment plants with TFs that currently nitrify downstream, this approach may be used to meet less stringent permitted discharge concentrations and may allow some facilities to postpone or eliminate construction of additional unit processes for denitrification. 相似文献