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31.
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
32.
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
33.
Large-scale silver nanowires (AgNWs) with a width of 50–60 nm and a typical length of 10 ± 5 μm were synthesized conveniently through a simple polyol reduction method, and the weight of obtained AgNWs was close to 10 g in this one-pot reaction with 500 ml of solution. The as-prepared AgNWs were incorporated into polyvinylidene fluoride matrix (PVDF) to fabricate the AgNWs/PVDF composites, and dielectric behaviors of the composites were investigated. The results revealed that a low percolation threshold of 1.8 vol% was observed in the AgNWs/PVDF composites, which was due to the large aspect ratio of one-dimension structured AgNWs. A giant dielectric constant of 80,000 at 1 kHz was obtained with 1.8 vol% of AgNWs mainly caused by the percolation effect. Besides, the large micro-capacitor networks and strong interfacial polarization at percolation threshold contributed to the enhanced dielectric constant. 相似文献
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Effects of POSS nanoparticles on glass transition temperatures of ultrathin poly(t‐butyl acrylate) films and bulk blends 下载免费PDF全文
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
35.
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
36.
Longxiang Liu Dr. Liqun Kang Dr. Arunabhiram Chutia Jianrui Feng Dr. Martyna Michalska Dr. Pilar Ferrer Dr. David C. Grinter Prof. Georg Held Yeshu Tan Fangjia Zhao Fei Guo Dr. David G. Hopkinson Dr. Christopher S. Allen Dr. Yanbei Hou Junwen Gu Prof. Ioannis Papakonstantinou Prof. Paul R. Shearing Prof. Dan J. L. Brett Prof. Ivan P. Parkin Prof. Dr. Guanjie He 《Angewandte Chemie (International ed. in English)》2023,62(21):e202303525
The electrochemical synthesis of hydrogen peroxide (H2O2) via a two-electron (2 e−) oxygen reduction reaction (ORR) process provides a promising alternative to replace the energy-intensive anthraquinone process. Herein, we develop a facile template-protected strategy to synthesize a highly active quinone-rich porous carbon catalyst for H2O2 electrochemical production. The optimized PCC900 material exhibits remarkable activity and selectivity, of which the onset potential reaches 0.83 V vs. reversible hydrogen electrode in 0.1 M KOH and the H2O2 selectivity is over 95 % in a wide potential range. Comprehensive synchrotron-based near-edge X-ray absorption fine structure (NEXAFS) spectroscopy combined with electrocatalytic characterizations reveals the positive correlation between quinone content and 2 e− ORR performance. The effectiveness of chair-form quinone groups as the most efficient active sites is highlighted by the molecule-mimic strategy and theoretical analysis. 相似文献
37.
Amreen A. Hussain Shyamalima Sharma Arup R. Pal Heremba Bailung Joyanti Chutia Dinkar S. Patil 《Plasma Chemistry and Plasma Processing》2012,32(4):817-832
The role of plasma parameters on the film characteristics is investigated on polyaniline thin film deposited by radio frequency (RF) plasma polymerization. A series of un-doped and iodine doped polyaniline thin films are prepared by RF discharge operating at 13.56?MHz with different discharge powers and pressure variation from 0.1 to 0.05?mbar and variation in deposition time from 20 to 40?min. A good thin film is found with a power ranging from 9?W (?28?V self bias) to 20?W (?65?V self bias) at 0.1?mbar pressure which is confirmed by fourier transform infra-red spectroscopy showing the retention of aromatic rings. In addition, iodine doping is carried out with 9?W power and 0.1?mbar pressure. The characterization of process plasma is done using Langmuir probe diagnostics and optical emission spectroscopy. A correlation has been established between film characteristics and plasma properties investigated using optical emission spectroscopy and Langmuir probe analysis. Emphasis has been given on the study of the influence of plasma parameters, particularly of the electron energy distribution function on the quality of conjugated plasma polymerized aniline film. 相似文献
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A mild and efficient method for the synthesis of diverse isoindolinones from o-phthaldehydic acid methylthiomethyl ester and aliphatic/aromatic amines has been developed. A number of nucleophiles including a hydride ion were successfully added to the intermediate Schiff's base providing isoindolinones, with or without substitution at 3-position. Conditions have also been developed for amines with an integrated nucleophilic group to react in a diverse fashion either to give isoindolinones or tricyclic γ-lactams as single diastereoisomers in very good yield. 相似文献
40.
Kar P Biswas R Drew MG Ida Y Ishida T Ghosh A 《Dalton transactions (Cambridge, England : 2003)》2011,40(13):3295-3304
The preparation, crystal structures and magnetic properties of two new isoelectronic and isomorphous formate- and nitrite-bridged 1D chains of Mn(III)-salen complexes, [Mn(salen)(HCOO)](n) (1) and [Mn(salen)(NO(2))](n) (2), where salen is the dianion of N,N'-bis(salicylidene)-1,2-diaminoethane, are presented. The structures show that the salen ligand coordinates to the four equatorial sites of the metal ion and the formate or nitrite ions coordinate to the axial positions to bridge the Mn(III)-salen units through a syn-antiμ-1κO:2κO' coordination mode. Such a bridging mode is unprecedented in Mn(III) for formate and in any transition metal ion for nitrite. Variable-temperature magnetic susceptibility measurements of complexes 1 and 2 indicate the presence of ferromagnetic exchange interactions with J values of 0.0607 cm(-1) (for 1) and 0.0883 cm(-1) (for 2). The ac measurements indicate negligible frequency dependence for 1 whereas compound 2 exhibits a decrease of χ(ac)' and a concomitant increase of χ(ac)' on elevating frequency around 2 K. This finding is an indication of slow magnetization reversal characteristic of single-chain magnets or spin-glasses. The μ-nitrito-1κO:2κO' bridge seems to be a potentially superior magnetic coupler to the formate bridge for the construction of single-molecule/-chain magnets as its coupling constant is greater and the χ(ac)' and χ(ac)' show frequency dependence. 相似文献