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91.
In this article, we have decorated multiwalled carbon nanotubes (MWCNTs) scaffold with ZnO quantum dots (QDs, size in the
range of 2.9–4.5 nm) and investigated their prospects for photovoltaic applications. ZnO QDs, in the present study, work
as photosensitizer instead of electron transporting media as used in recent conventional strategic solar cells. ZnO QDs/MWCNTs
composite shows an increased visible absorbance and quenching of the broad visible emission at around ~560 nm, while only
ZnO QDs exhibit a strong visible emission. An efficient electron–hole separation facilitates an increase in the short-circuit
current. These results show a possibility of developing a nontoxic, ZnO QDs sensitized MWCNTs composite-based photovoltaic
solar cell. 相似文献
92.
Tanmoy Dutta Yong Li Aaron L. Thornton Da‐Ming Zhu Zhonghua Peng 《Journal of polymer science. Part A, Polymer chemistry》2013,51(18):3818-3828
Donor‐acceptor conjugated polymers containing a new imide‐functionalized naphthodithiophene (INDT) as the acceptor unit and a 2,2'‐bithiophene with varied substituents as the donor unit have been synthesized. The bandgaps of these polymers depend strongly on the dihedral angle of the 2,2'‐bithiophene unit. The 3,3'‐dialkoxy substitution (polymers PDOR / PBOR ) leads to near planar bithiophene conformation due to the well‐known S–O short contact, while the 3,3'‐dialkyl substitution (polymer PDR ) results in significant twisting due to the steric effect. Consequently PDOR / PBOR shows the lowest bandgap of 1.82/1.85 eV while PDR has a bandgap of 2.38 eV. Bulk‐heterojunction solar cells of the polymer/fullerene blends have been fabricated. Preliminary results show that PBOR gives the best device performance with power conversion efficiencies as high as 2.45% in air without any thermal annealing treatment, indicating the promising potential of INDT‐containing conjugated polymers for efficient solar cells. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3818–3828 相似文献
93.
The reactions of dimeric complex [Rh(CO)2Cl]2 with hemilabile ether‐phosphine ligands Ph2P(CH2) nOR [n = 1, R = CH3 (a); n = 2, R = C2H5 (b)] yield cis‐[Rh(CO)2Cl(P ~ O)] (1) [P ~ O = η 1‐(P) coordinated]. Halide abstraction reactions of 1 with AgClO4 produce cis‐[Rh(CO)2(P ∩ O)]ClO4 (2) [P ∩ O = η 2‐(P,O)chelated]. Oxidative addition reactions of 1 with CH3I and I2 give rhodium(III) complexes [Rh(CO)(COCH3)ClI(P ∩ O)] (3) and [Rh(CO)ClI2(P ∩ O)] (4) respectively. The complexes have been characterized by elemental analyses, IR, 1H, 13C and 31P NMR spectroscopy. The catalytic activity of 1 for carbonylation of methanol is higher than that of the well‐known [Rh(CO)2I2]? species. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
94.
It is well known that the generalized Nash equilibrium problem, a model for multi-leader–follower games, can be reformulated as a quasivariational inequality. We show that, in fact, a reformulation in terms of a variational inequality can be obtained in the general setting of quasiconvex nondifferentiable decision functions. An existence result is deduced. 相似文献
95.
Dibyendu S. Bag Dhiraj Dutta T. C. Shami K. U. Bhasker Rao 《Journal of polymer science. Part A, Polymer chemistry》2009,47(9):2228-2242
A chiral monomer containing L ‐leucine as a pendant group was synthesized from methacryloyl chloride and L ‐leucine in presence of sodium hydroxide at 4 °C. The monomer was polymerized by free radical polymerization in propan‐2‐ol at 60 °C using 2,2′‐azobis isobutyronitrile (AIBN) as an initiator under nitrogen atmosphere. The polymer, poly(2‐(Methacryloyloxyamino)‐4‐methyl pentanoic acid) is thus obtained. The molecular weight of the polymer was determined to be: Mw is 6.9 × 103 and Mn is 5.6 × 103. The optical rotation of both chiral monomer and its polymer varies with the solvent polarity. The amplification of optical rotation due to transformation of monomer to polymer is associated with the ordered conformation of chiral monomer unit in the polymeric chain due to some secondary interactions like H‐bonding. The synthesized monomer and polymer exhibit intense Cotton effect at 220 nm. The conformation of the chain segments is sensitive to external stimuli, particularly the pH of the medium. In alkaline medium, the ordered chain conformation is destroyed resulting disordered random coils. The ordered coiling conformation is more firmly present on addition of HCl. The polymer exhibits swelling‐deswelling characteristics with the change of pH of the medium, which is reversible. The Cotton effect decreases linearly with the increase of temperature which is reversible on cooling. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2228–2242, 2009 相似文献
96.
We study the effect of a nearby phase-conjugate mirror (PCM) on the gap soliton of a Kerr non-linear periodic structure. We
show that phase conjugation of the gap soliton (in the sense of replication of the amplitude profile in the reverse direction)
is possible under the condition of PCM reflectivity approaching unity. This is in contrast with the results for linear structures,
where the wave profiles can be conjugated for arbitrary values of the PCM reflectivity. The sensitivity of the conjugation
of the gap solitons to PCM reflectivity is ascribed to the fine balance of non-linearity with dispersion, necessary for their
existence. 相似文献
97.
Debajyoti Choudhury Saurabh D. Rindani B. Ananthanarayan K. R. S. Balaji Debajyoti Choudhury Manuel Drees Shashikant Dugad Gautam Dutta Sukanta Dutta Naveen Gaur Ambar Ghosal Walter Grimus Ernest Ma Shubhendra Mohanty P. N. Pandita M. K. Parida Subhendu Rakshit Saurabh D. Rindani D. P. Roy Probir Roy Sarira Sahu N. N. Singh Sudhir K. Vempati Francesco Vissani 《Pramana》1998,51(1-2):305-311
This report summarises the activities of the working group on ‘Physics beyond the Standard Model’. The results of investigations
in incorporatingR-parity in grand unification, the possibility of a light charged Higgs boson in extension of MSSM and radiative generation
of neutral vector boson self-couplings within the MSSM are described. Also given is an account of activities in neutrino physics,
namely a proposal for a study of the atmospheric muon anomaly in deep underground mines, a field theoretic study of neutrino
oscillations and a mechanism to generate appropriate masses of three active plus one sterile neutrino species. 相似文献
98.
We study third harmonic generation in layered configuration when the fundamental exhibits bistable response. We consider two
geometries, namely, a Fabry-Perot cavity with reflection coatings and a distributed feedback structure with alternate nonlinear
layers. In both the cases for suitable choice of frequency, the power response at the fundamental frequency is bistable. We
show that bistability of the fundamental leads to a multivalued character of the generated third harmonic in both the forward
and backward directions. Moreover, we study frequency response in the case of the Fabry-Perot cavity and show that additional
structures arise in the generated third harmonic due to frequency bistability of the fundamental. Our calculations suggest
the possibility of an all optical switch at third harmonic frequency controlled by the parameters (like intensity, frequency)
of the fundamental. 相似文献
99.
The hard photon production from bremsstrahlung and annihilation with scattering that arise at two-loop level are estimated for a chemically non-equilibrated quark–gluon plasma in the framework of Hard Thermal Loop (HTL) resummed effective field theory. The rate of photon production is found to be suppressed due to unsaturated phase space compared to equilibrated plasma. For an unsaturated plasma, unlike the effective one-loop case, the reduction in the effective two-loop processes is found to be independent of gluon fugacity, due to an additional collinear enhancement arising from the decrease in thermal quark mass but strongly depends on quark and antiquark fugacities. It is also found that the photon production is dominated by bremsstrahlung mechanism, since the phase space suppression is higher for annihilation with scattering, in contrast to the equilibrated plasma where annihilation with scattering dominates the photon production. 相似文献
100.
N. K. Dutta N. D. Tran N. R. Choudhury 《Journal of Polymer Science.Polymer Physics》2005,43(11):1392-1400
Scanning thermal microscopy (SThM) has been used for the visualization and characterization of an ultrathin plasma polymer film of perfluoro(methylcyclohexane) at a submicrometer level. The morphology, molecular dynamics, and lateral homogeneity of the ultrathin film have all been examined precisely with SThM. The growth of the plasma polymer film on a silicon wafer (Si‐wafer) has also been precisely determined using a new burning‐hole technique. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1392–1400, 2005 相似文献