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131.
A new approach to prepare and characterize double network elastomeric systems was investigated. A styrene‐ethylene‐co‐butylene‐styrene (SEBS) triblock copolymer system containing physical crosslinks was used to achieve a double network by additional crosslinking using ultra‐violet (UV) light. An ethylene–propylene–diene monomer (EPDM) terpolymer system containing chemical crosslinks was used to achieve a conventional double network using UV crosslinking. Properties from conventional monotonic tensile tests, dynamic mechanical analysis, and thermomechanical properties were investigated. These double network elastomers show a transition between competitive and collaborative behavior in their mechanical properties and lower coefficients of thermal expansion arising from a competition of the networks. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 778–789, 2010 相似文献
132.
T.M. Aliev S. Rai Choudhury A.S. Cornell Naveen Gaur 《The European Physical Journal C - Particles and Fields》2007,49(3):657-664
Standard model (SM) CP asymmetries in B→Kℓ+ℓ- are expected to be very small. This feature could help in the understanding of new physics scenarios which predict the existence
of CP odd phases in various Wilson coefficients. In this paper we have analyzed the B→Kℓ+ℓ- decay in scenarios beyond the SM where the Wilson coefficients have new CP odd phases. The sensitivity of the CP asymmetries
on these new weak phases is discussed.
PACS 13.20.He; 12.60.-i; 13.88.+e 相似文献
133.
134.
The self-focusing of a laser pulse through a tunnel ionizing gas (helium) has been studied in both non-relativistic and relativistic
regimes, relaxing the near-axis approximation. In the non-relativistic regime, the laser pulse produces multiple ionization
of the gas and faces strong defocusing due to the steep radial density gradient caused by the same. The uneven defocusing
of paraxial and marginal rays leads to a beam acquiring a ring shaped intensity distribution. In the relativistic regime,
the laser pulse produces fully ionized plasma within a few wave periods, subsequently the relativistic mass effect and the
ponderomotive force induced electron cavitation cause periodic self-focusing.
PACS 52.38.Hb; 42.65.Jx 相似文献
135.
Akshay Kumar Vivek SharmaJasneet Kaur Vikas KumarSuhel Mahajan Naveen KumarSwapandeep Singh Chimni 《Tetrahedron》2014
A highly enantioselective addition of diphenyl phosphite to ketimines derived from isatins has been developed employing bifunctional thiourea-tertiary amine organocatalysts. A variety of isatins derived ketimines react well with diphenyl phosphite in the presence of Cinchona-derived thiourea (epiCDT) to provide biologically important chiral 3-substituted 3-amino-2-oxindoles (3a–l) in good yield (up to 88%) and good enantioselectivity (up to 97% ee). The three-component version of the reaction through a domino aza-Wittig/phospha-Mannich sequence has successfully been explored. 相似文献
136.
The main objectives of the present work are firstly to study and compare the thin layer drying characteristics of fenugreek leaves by open sun and solar drying methods, and secondly to select a mathematical model for describing the drying process under open sun and solar drying of fenugreek leaves using thin layer drying models available in the literature. Eight thin layer drying models, which are empirical or semi-empirical, are tested to validate the experimental data. A non-linear regression analysis using a statistical computer programme is used to evaluate the constants of the models. The performance of the models was investigated by comparing the coefficient of correlation (R 2), sum of squares error (SSE), mean squared error (MSE) and root mean square error (RMSE) between observed and predicted moisture ratios. According to results, Wang and Singh model gives the highest value of R 2 and the lowest values of SSE, MSE and RMSE. Therefore, Wang and Singh model is the best for explaining drying behaviour of fenugreek leaves in both the trays inside the solar dryer and in the tray under open sun. 相似文献
137.
Palladium‐Catalyzed Annulation of Diarylamines with Olefins through CH Activation: Direct Access to N‐Arylindoles 下载免费PDF全文
Dr. Upendra Sharma Dr. Rajesh Kancherla Togati Naveen Soumitra Agasti Prof. Debabrata Maiti 《Angewandte Chemie (International ed. in English)》2014,53(44):11895-11899
A palladium‐catalyzed dehydrogenative coupling between diarylamines and olefins has been discovered for the synthesis of substituted indoles. This intermolecular annulation approach incorporates readily available olefins for the first time and obviates the need of any additional directing group. An ortho palladation, olefin coordination, and β‐migratory insertion sequence has been proposed for the generation of olefinated intermediate, which is found to produce the expected indole moiety. 相似文献
138.
Shaik Firoj Basha Tangella Nagendra Prasad Veera Babu Gudise Vadiga Shanthi Kumar Naveen Mulakayala 《合成通讯》2013,43(22):3181-3190
AbstractA facile one-pot synthesis of ethyl 5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine, 5-tert-butyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine, 6,6-dimethyl-5,6,7,9-tetrahydrotetrazolo[5,1-b]quinazolin-8(4H)-one and 5,6,7,9-tetrahydrotetrazolo[5,1-b]quinazolin-8(4H)-one derivatives were described via a three-component reaction of aldehyde, 5-aminotetrazole and diketones in PEG-400 under microwave irradiation at 110?°C for 30?min. A wide range of diketones such as ethylacetoacetate, tert-butyl acetoacetate, 5,5-dimethylcyclohexane-1,3-dione and 1,3-cyclohexanedione were utilized to carry out the synthesis of different dihydrotetrazolo[1,5-a]pyrimidines and tetrahydrotetrazolo[1,5-a]quinazolinones. This method has the advantage of green protocol, operational simplicity, high yields, recyclability of the solvent and involves isolation of the final product without column purification. The scope of this reaction tolerates with aromatic, heteroaromatic and alicyclic aldehydes. 相似文献
139.
H. M. Meshram B. Chennakesava Reddy B. R. V. Prasad P. Ramesh Goud G. Santosh Kumar R. Naveen Kumar 《合成通讯》2013,43(11):1669-1676
An efficient and convenient synthesis of benzofurans has been described from phenacyl halides and o-hydroxy benzaldehyde in the presence of DABCO. The procedure is applicable for a variety of phenacyl halides and provide a variety of benzofurans. DABCO act as a base and as well as nucleophile. 相似文献
140.
Adel A. Abdelwahab Dong‐Min Kim Naveen M. Halappa Yoon‐Bo Shim 《Electroanalysis》2013,25(5):1178-1184
A simple detection method of ascorbic acid (AA) through selective catalytic oxidation has been developed using a novel conducting polymer poly‐3′‐(2‐aminopyrimidyl)‐2,2′:5′,2“‐terthiophene (pAPTT). The pAPTT electrode showed an excellent selectivity in facilitating the electron transfer of AA and blocked the interferences of cationic species due to the positively charged pAPTT film. This method proved to be effective in the determination of AA in the presence of various biological interfering species. The dynamic range of AA detection was from 10 to 200 µM and the detection limit was 1.4±0.06 µM. 相似文献