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排序方式: 共有792条查询结果,搜索用时 9 毫秒
61.
Nintu Mandal S. C. Datta K. M. Manjaiah B. S. Dwivedi R. Kumar P. Aggarwal 《Polymer-Plastics Technology and Engineering》2018,57(17):1760-1770
Novel zincated nanoclay polymer composites (ZNCPCs) with variable percentage of commercial bentonite and nanobentonite (8%, 10% and 12% of monomer for each case) were synthesized. Polyacrylic acid-Polyacrylamide copolymer was synthesized using N, N-Methylene bisacrylamide as crosslinker and ammonium persulfate as initiator. Clays as well as ZNCPCs were characterized by XRD, SEM, TEM and FTIR. 12% nanoclay containing formulation showed slowest release rate. ZNCPCs containing 8% clay recorded highest Zn content as well as highest equilibrium water absorbency. Biodegradation study revealed that Aspergillus spp was more effective as compared with Trichoderma spp in degradation of ZNCPCs. 相似文献
62.
Sanghera J.S. Nguyen V.Q. Pureza P.C. Kung F.H. Miklos R. Aggarwal I.D. 《Lightwave Technology, Journal of》1994,12(5):737-741
Improved purification and processing techniques have been utilized to fabricate Ge30As10Se30Te30 glass fibers with a minimum loss of O.11 dB/m at 6.6 μm. This is the lowest loss reported for any telluride glass fiber in the infrared region. Furthermore, the fibers exhibit less than 1 dB/m loss between 5.25 and 9.5 μm 相似文献
63.
Competitive electricity markets are undergoing a rapid transformation from systems with large, inflexible baseload resources to ones with smaller, modular, variable resources. Making the grid more flexible is critical to enabling a smooth transition. A significant amount of unused flexibility exists in the system today, but harnessing it requires changes to market rules. 相似文献
64.
Rodriguez J.A. Remack K. Boku K. Udayakumar K.R. Aggarwal S. Summerfelt S.R. Celii F.G. Martin S. Hall L. Taylor K. Moise T. McAdams H. McPherson J. Bailey R. Fox G. Depner M. 《Device and Materials Reliability, IEEE Transactions on》2004,4(3):436-449
We report on the reliability properties of ferroelectric capacitors and memory arrays embedded in a 130-nm CMOS logic process with 5LM Cu/FSG. Low voltage (<1.5 V) operation is enabled by the 70-nm thick MOCVD PZT ferroelectric films. Data loss resulting from high temperature bakes is primarily caused by the imprint effect, which shows /spl sim/1.5 eV time-to-fail activation energy. Excellent bit endurance properties are observed on fully packaged memory arrays, with no degradation up to 10/sup 13/ write/read polarization switching cycles. Retention measured after 10/sup 12/ switching cycles demonstrates no degradation relative to arrays with minimal cycling. 相似文献
65.
66.
ABSTRACTIn the present work, the self-organized pattern formation with simultaneous surface smoothing of Polyethylene terephthalate (PET) by 40 keV Ar+ ions irradiation has been discussed. The effect of most important experimental parameter i.e. ion beam incidence that control these processes has been discussed by varying off normal incidences from 300 to 500. The changes in surface topography have been studied using Atomic Force Microscopy (AFM). It has been investigated from AFM analysis that oblique ion beam induced sputtering significantly reduced the surface roughness with simultaneous formation of some hillock and hole like structures. 相似文献
67.
A novel series of sulfur-containing dihydrochromeno[8,7-e][1,3]oxazine-2(8H)-thiones has been synthesized through an eco-friendly Mannich-type condensation cyclization reaction of 7-hydroxy-4-methyl-2-thiocoumarin or 6-chloro-7-hydroxy-4-methyl-2-thiocoumarin with formaldehyde and primary amines in water at 80–90°C for 2 h. All the synthesized compounds were screened for their in vitro anti-bacterial efficacy against two Gram-positive and three Gram-negative bacterial strains by using the disc diffusion method. The compound (8c) was found to be most potent with the zone of inhibition of 16 and 15 mm against Staphylococcus aureus ATCC 2937 and Klebsiella pneumoniae ATCC 31488, respectively. 相似文献
68.
Tso Yee Fan Ripin D.J. Aggarwal R.L. Ochoa J.R. Bien Chann Tilleman M. Spitzberg J. 《IEEE journal of selected topics in quantum electronics》2007,13(3):448-459
Cryogenically cooled solid-state lasers promise a revolution in power scalability while maintaining a good beam quality because of significant improvements in efficiency and thermo-optic properties. This is particularly true for Yb lasers because of their relatively low quantum defect and relatively broadband absorption even at cryogenic temperatures. Thermo-optic properties of host materials, including thermal conductivity, thermal expansion, and refractive index at low temperature, are reviewed and data presented for YAG (ceramic and single crystal), GGG, GdVO4, and Y2O3. Spectroscopic properties of Yb:YAG and Yb:LiYF4 (YLF) including absorption cross sections, emission cross sections, and fluorescence lifetimes at cryogenic temperatures are characterized. Recent experiments have pushed the power from an end-pumped cryogenically cooled Yb:YAG laser to 455-W continuous-wave output power from 640-W incident pump power at an of M2 1.4. 相似文献
69.
Hevea brasiliensis ) esterified with acetic anhydride, maleic anhydride and phthalic anhydride was studied for moisture adsorption behaviour.
FTIR spectroscopic technique was used to analyse the chemical changes in the wood through the correspondent reactions. Spectra
indicated increasing intensity of the C=O and C-O stretching bands, and reduction in O-H stretching vibrations that reflects
formation of less hygroscopic ester bonds with hydroxyl groups of cell wall polymers. Moisture adsorption isotherms show low
equilibrium moisture content in esterified wood at all relative humidity values as compared to a control. The adsorption data
was analysed by applying Hailwood-Horrobin theory which separated the adsorbed water into hydrated water and dissolved water
corresponding to mono-layer and multi-layer adsorption. Curve for Mh and Ms were similar in pattern for esterified wood and control with different magnitude. Low Mh and Ms in esterified wood indicate reduction in moisture adsorption sites. Inaccessible fraction of wood for water vapour was increased
by 43%, 32% and 26% in acetic, maleic and phthalic anhydride treated wood, respectively, compared to the control. Acetic anhydride
treatment was found most effective in reducing hygroscopicity of wood.
Hevea brasiliensis ) wurde verestert mit Anhydriden der Maleins?ure, Essigs?ure und Phtals?ure. Das Adsorptionsverhalten bei verschiedenen Feuchten wurde mit FTIR-Methoden untersucht, um die entsprechenden chemischen Abl?ufe zu erfassen. Intensivere C=O, und -C-O- Streckschwingungen sowie reduzierte OH-Schwingungen reflektieren die neu gebildeten, weniger hygroskopischen Esterbindungen. Bei allen modifizierten Proben ergaben sich niedrigere Gleichgewichtsfeuchten. Die Adsorptions-Isothermen wurden mit Hilfe der Hailwood-Horrobin Theorie analysiert, um adsorbiertes (Mh) und gel?stes (Ms) Wasser zu unterscheiden. Der Kurvenverlauf für Mh und Ms für modifiziertes und unbehandeltes Holz war qualitativ ?hnlich, und unterschied sich nur quantitativ. Geringe Werte für Mh und Ms zeigen eine Verringerung der m?glichen Adsorptionsstellen an. Der nicht zug?ngliche Anteil des Holzes, bezogen auf Kontrollproben, verringerte sich auf 43% (Acetanhydrid), 32% (Maleins?ureanhydrid) und 26% (Phthals?ureanhydrid). Acetanhydrid erwies sich als das effektivste Mittel, um die Hygroskopizit?t zu erniedrigen.相似文献
70.