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Effects of POSS nanoparticles on glass transition temperatures of ultrathin poly(t‐butyl acrylate) films and bulk blends
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Ufuk Karabiyik Rituparna Paul Michael C. Swift Sushil K. Satija Alan R. Esker 《Journal of Polymer Science.Polymer Physics》2015,53(3):175-182
As a model system, thin films of trisilanolphenyl‐POSS (TPP) and two different number average molar mass (5 and 23 kg mol?1) poly(t‐butyl acrylate) (PtBA) were prepared as blends by Langmuir–Blodgett film deposition. Films were characterized by ellipsometry. For comparison, bulk blends are prepared by solution casting and the samples are characterized via differential scanning calorimetry. The increase in Tg as a function of TPP content for bulk high and low molar mass samples are in the order of ~10 °C. Whereas bulk Tg shows comparable increases for both molar masses (~10 °C), the increase in surface Tg for higher molar mass PtBA is greater than for low molar mass (~22 °C vs. ~10 °C). Nonetheless, the total enhancement of Tg is complete by the time 20 wt % TPP is added without further benefit at higher nanofiller loads. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 175–182 相似文献
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T. Sinha Rituparna Kanungo C. Samanta Sudip Ghosh P. Basu H. Rebel 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):397-400
Alpha- particle scattering from the resonant (3 1 + ) and non-resonant continuum states of6Li is studied at incident energy 10 MeV/A. Theα+d breakup continuum part within the excitation energyE ex=1.475–2.475 MeV is discretized in two energy bins. Unlike the results at higher incident energies, here the coupled-channel calculations show significant breakup continuum coupling effects on the elastic and inelastic scattering. It is shown that even when the continuum-continuum coupling effects are strong, the experimental data of the ground state and the resonant as well as discretized non-resonant continuum states impose stringent constraint on the coupling strengths of the non-resonant continuum states. 相似文献
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Kundu R Cushing PR Popp BV Zhao Y Madden DR Ball ZT 《Angewandte Chemie (International ed. in English)》2012,51(29):7217-7220
Together strong: Cooperative binding of organic (see picture, red) and inorganic fragments provides a strategy for the potent inhibition of protein-protein interactions. By targeting specific Lewis basic side chains in peripheral regions of the binding site for coordination to a rhodium(II) center, the affinity of otherwise weak ligands is improved. 相似文献
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Biswas R Kar P Song Y Ghosh A 《Dalton transactions (Cambridge, England : 2003)》2011,40(19):5324-5331
Two new nickel(II) complexes [Ni(2)L(2)(PhCOO)(2)(H(2)O)] (1), [Ni(2)L(2)(PhCH(2)COO)(2)(H(2)O)] (2) have been synthesized using a tridentate Schiff base ligand, HL (2-[(3-dimethylamino-propylimino)-methyl]-phenol) and the carboxylate monoanions, benzoate and phenylacetate, respectively. The complexes have been characterized by spectral analysis, variable temperature magnetic susceptibility measurement and crystal structure analysis. The structural analyses reveal that both complexes are dinuclear in which the distorted octahedral Ni(2+) ions share a face, bridged by one water molecule and two μ(2)-phenoxo oxygen atoms. A monodentate benzoate or phenylacetate anion and two nitrogen atoms of the chelating deprotonated Schiff base (L) complete the hexa-coordination around the metal ion. Variable-temperature magnetic susceptibility studies indicate the presence of dominant ferromagnetic exchange coupling in complexes 1 and 2 with J values of 11.1(2) and 10.9(2) cm(-1) respectively. An attempt has been made to rationalize the observed magneto-structural behavior considering the importance of the additional water bridge in the present two complexes and also in other similar species. 相似文献
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Rituparna Mandal Sukanta Bhattacharyya Sunandan Gangopadhyay 《General Relativity and Gravitation》2018,50(11):143
We study the phase transition of rainbow inspired higher dimensional Schwarzschild black hole incorporating the effects of the generalized uncertainty principle. First, we obtain the relation between the mass and Hawking temperature of the rainbow inspired black hole taking into account the effects of the modified dispersion relation and the generalized uncertainty principle. The heat capacity is then computed from this relation which reveals that there are remnants. The entropy of the black hole is next obtained in \(3+1\) and \(4+1\)-dimensions and is found to have logarithmic corrections only in \(3+1\)-dimensions. We further investigate the local temperature, free energy and stability of the black hole in an isothermal cavity. From the analysis of the free energy, we find that there are two Hawking–Page type phase transitions in \(3+1\) and \(4+1\)-dimensions if we take into account the generalized uncertainty principle. However, in the absence of the generalized uncertainty principle, only one Hawking–Page type phase transition exists in spacetime dimensions greater than four. 相似文献
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Kanungo R Chiba M Iwasa N Nishimura S Ozawa A Samanta C Suda T Suzuki T Yamaguchi T Zheng T Tanihata I 《Physical review letters》2002,88(14):142502
The longitudinal momentum (P(axially)) distributions of one- and two-neutron removal fragments ((21,22)O) of 23O from the reaction with a C target at 72 A MeV have been measured for the first time using a new direct time-of-flight method with nearly full acceptance for the breakup fragments. The unexpectedly narrow width of 21O ( 115 +/- 34 MeV/c in FWHM) is consistent with two neutrons occupying the 2s(1/2) orbital in 23O. This indicates modification of core (22O) structure for neutron halo-like sd shell nuclei near the drip line. This also suggests the lowering of the s orbital providing a justification for the N = 16 magic number. 相似文献
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Maji Rituparna Behera Bikash K. Panigrahi Prasanta K. 《International Journal of Theoretical Physics》2021,60(5):1980-1988
International Journal of Theoretical Physics - Quantum algorithm, as compared to classical algorithm, plays a notable role in solving linear systems of equations with an exponential speedup. Here,... 相似文献
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Roy RS Gopi HN Raghothama S Karle IL Balaram P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(12):3295-3302
The effects of inserting unsubstituted omega-amino acids into the strand segments of model beta-hairpin peptides was investigated by using four synthetic decapeptides, Boc-Leu-Val-Xxx-Val-D-Pro-Gly-Leu-Xxx-Val-Val-OMe: peptide 1 (Xxx=Gly), peptide 2 (Xxx=betaGly=betahGly=homoglycine, beta-glycine), peptide 3 (Xxx=gammaAbu=gamma-aminobutyric acid), peptide 4 (Xxx=deltaAva=delta-aminovaleric acid). 1H NMR studies (500 MHz, methanol) reveal several critical cross-strand NOEs, providing evidence for beta-hairpin conformations in peptides 2-4. In peptide 3, the NMR results support the formation of the nucleating turn, however, evidence for cross-strand registry is not detected. Single-crystal X-ray diffraction studies of peptide 3 reveal a beta-hairpin conformation for both molecules in the crystallographic asymmetric unit, stabilized by four cross-strand hydrogen bonds, with the gammaAbu residues accommodated within the strands. The D-Pro-Gly segment in both molecules (A,B) adopts a type II' beta-turn conformation. The circular dichroism spectrum for peptide 3 is characterized by a negative CD band at 229 nm, whereas for peptides 2 and 4, the negative band is centered at 225 nm, suggesting a correlation between the orientation of the amide units in the strand segments and the observed CD pattern. 相似文献
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