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101.
Recent experiments on 2H-TaSe(2) contradict the long-held view of the charge density wave arising from a nested band structure. An intrinsically strong coupling view, involving a charge density wave state arising as a Bose condensation of preformed excitons emerges as an attractive, albeit scantily investigated alternative. Using the local density approximation plus multiorbital dynamic mean field theory, we show that this scenario agrees with a variety of normal state data for 2H-TaSe(2). Based thereupon, the ordered states in a subset of dichalcogenides should be viewed as instabilities of a correlated, preformed excitonic liquid. 相似文献
102.
Ujjwal Koley Nils Henrik Risebro 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2013,64(4):1057-1085
We are concerned with the convergence of numerical schemes for the initial value problem associated with the Keyfitz–Kranzer system of equations. This system is a toy model for several important models such as in elasticity theory, magnetohydrodynamics, and enhanced oil recovery. In this paper, we prove the convergence of three difference schemes. Two of these schemes are shown to converge to the unique entropy solution. Finally, the convergence is illustrated by several examples. 相似文献
103.
Moumita Dey Santanu K. Maiti S. N. Karmakar 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,80(1):105-114
We examine spin dependent transport in a quantum interferometer composed of
magnetic atomic sites based on transfer matrix formalism. The interferometer,
threaded by a magnetic flux ϕ, is symmetrically attached to two
semi-infinite one-dimensional (1D) non-magnetic electrodes, namely, source
and drain. A simple tight-binding model is used to describe the bridge system,
and, here we address numerically the conductance-energy and current-voltage
characteristics as functions of the interferometer-to-electrode coupling
strength, magnetic flux and the orientation of local the magnetic moments
associated with each atomic site. Quite interestingly it is observed that,
for ϕ = ϕ
0/2 (ϕ
0 = ch/e, the elementary flux-quantum) a
logical XOR gate like response is observed, depending
on the orientation of the local magnetic moments associated with the
magnetic atoms in the upper and lower arms of the interferometer, and it
can be changed by an externally applied gate magnetic field. This aspect
may be utilized in designing a spin based electronic logic gate. 相似文献
104.
Meccanica - In this paper, the water waves scattering by a new type of floating porous breakwater is investigated numerically under the assumption of two-dimensional linearized wave-structure... 相似文献
105.
Exploring the Oxidative‐Addition Pathways of Phenyl Chloride in the Presence of PdII Abnormal N‐Heterocyclic Carbene Complexes: A DFT Study
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Totan Mondal Sriman De Bholanath Maity Dr. Debasis Koley 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(44):15778-15790
DFT calculations were performed to elucidate the oxidative addition mechanism of the dimeric palladium(II) abnormal N‐heterocyclic carbene complex 2 in the presence of phenyl chloride and NaOMe base under the framework of a Suzuki–Miyaura cross‐coupling reaction. Pre‐catalyst 2 undergoes facile, NaOMe‐assisted dissociation, which led to monomeric palladium(II) species 5 , 6 , and 7 , each of them independently capable of initiating oxidative addition reactions with PhCl. Thereafter, three different mechanistic routes, path a, path b, and path c, which originate from the catalytic species 5 , 7 , and 6 , were calculated at M06‐L ‐D3(SMD)/LANL2TZ(f)(Pd)/6–311++G**//M06‐L/LANL2DZ(Pd)/6–31+G* level of theory. All studied routes suggested the rather uncommon PdII/PdIV oxidative addition mechanism to be favourable under the ambient reaction conditions. Although the Pd0/PdII routes are generally facile, the final reductive elimination step from the catalytic complexes were energetically formidable. The PdII/PdIV activation barriers were calculated to be 11.3, 9.0, 26.7 kcal mol?1 (ΔΔ≠GLS‐D3) more favourable than the PdII/Pd0 reductive elimination routes for path a, path b, and path c, respectively. Out of all the studied pathways, path a was the most feasible as it comprised of a PdII/PdIV activation barrier of 24.5 kcal mol?1 (ΔGLS‐D3). To further elucidate the origin of transition‐state barriers, EDA calculations were performed for some key saddle points populating the energy profiles. 相似文献
106.
107.
Adity Bose Dibyangana Parbat Moumita Mukherjee Pinki Saha Sardar Sanjib Ghosh 《光谱学快报》2017,50(2):81-87
The present work demonstrates the photophysical characterization of the interaction of two antibacterial and antimicrobial compounds, thymol and its isomer, carvacrol with different biomimetic micellar nanocavities having varying surface charge characteristics. These types of molecules are reported to be photoacids and this behavior is remarkably exhibited upon interaction with the macromolecular assemblies of micellar systems in the presence of inorganic and organic quencher molecules (silver nitrate and diethylamine) and is manifested through significant modulations of the bimolecular quenching constant values. 相似文献
108.
Moumita Mandal Gnaneshwar Nelakanti 《Journal of Applied Mathematics and Computing》2018,57(1-2):247-260
In this paper, Galerkin method is applied to approximate the solution of Volterra integral equations of second kind with a smooth kernel, using piecewise polynomial bases. We prove that the approximate solutions of the Galerkin method converge to the exact solution with the order \({\mathcal {O}}(h^{r}),\) whereas the iterated Galerkin solutions converge with the order \({\mathcal {O}}(h^{2r})\) in infinity norm, where h is the norm of the partition and r is the smoothness of the kernel. We also consider the multi-Galerkin method and its iterated version, and we prove that the iterated multi-Galerkin solution converges with the order \({\mathcal {O}}(h^{3r})\) in infinity norm. Numerical examples are given to illustrate the theoretical results. 相似文献
109.
Moumita Mandal Gnaneshwar Nelakanti 《Journal of Applied Mathematics and Computing》2018,57(1-2):321-332
In this paper, we develop the iteration techniques for Galerkin and collocation methods for linear Volterra integral equations of the second kind with a smooth kernel, using piecewise constant functions. We prove that the convergence rates for every step of iteration improve by order \({\mathcal {O}}(h^{2})\) for Galerkin method, whereas in collocation method, it is improved by \({\mathcal {O}}(h)\) in infinity norm. We also show that the system to be inverted remains same for every iteration as in the original projection methods. We illustrate our results by numerical examples. 相似文献
110.
Phenylboronic Acid Appended Pyrene‐Based Low‐Molecular‐Weight Injectable Hydrogel: Glucose‐Stimulated Insulin Release
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Deep Mandal Subhra Kanti Mandal Moumita Ghosh Prof. Prasanta Kumar Das 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):12042-12052
A pyrene‐containing phenylboronic acid (PBA) functionalized low‐molecular‐weight hydrogelator was synthesized with the aim to develop glucose‐sensitive insulin release. The gelator showed the solvent imbibing ability in aqueous buffer solutions of pH values, ranging from 8–12, whereas the sodium salt of the gelator formed a hydrogel at physiological pH 7.4 with a minimum gelation concentration (MGC) of 5 mg mL?1. The aggregation behavior of this thermoreversible hydrogel was studied by using microscopic and spectroscopic techniques, including transmission electron microscopy, FTIR, UV/Vis, luminescence, and CD spectroscopy. These investigations revealed that hydrogen bonding, π–π stacking, and van der Waals interactions are the key factors for the self‐assembled gelation. The diol‐sensitive PBA part and the pyrene unit in the gelator were judiciously used in fluorimetric sensing of minute amounts of glucose at physiological pH. The morphological change of the gel due to addition of glucose was investigated by scanning electron microscopy, which denoted the glucose‐responsive swelling of the hydrogel. A rheological study indicated the loss of the rigidity of the native gel in the presence of glucose. Hence, the glucose‐induced swelling of the hydrogel was exploited in the controlled release of insulin from the hydrogel. The insulin‐loaded hydrogel showed thixotropic self‐recovery property, which hoisted it as an injectable soft composite. Encouragingly, the gelator was found to be compatible with HeLa cells. 相似文献