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111.
Aditya Kumar Ajeet Singh Animesh K. Ojha 《International journal of quantum chemistry》2019,119(22):e26012
Recently, hybrid organic-inorganic perovskite (HOIPs) materials are used to enhance the power conversion efficiency of the solar cells. The tolerance factor (TF) and octahedral factor (μ) are widely used to predict the formation of three-dimensional (3D) HOIPs structures. However, in some of the cases (e.g. CH3NH3GeI3 (MAGeI3) [TF = 1.06, μ = 0.33] NH2CHNH2GeI3 (FAGeI3) [TF = 1.14, μ = 0.33] and CH3C(NH2)2GeI3 (ACGeI3) [TF = 1.17, μ = 0.33]), these factors could not predict the formation of HOIPs structures. Thus, we have introduced a new factor based on the HOMO-LUMO energy gap of the organic cations, metal cations, anions, and volume of the organic cations. We have tested and utilized the HOMO-LUMO energy gap factor (β) on 403 ABX3 combinations. The factor β successfully predicts and differentiate the perovskite and non-perovskite materials. Further, we also observed that for the formation of HOIPs structure, volume of the organic cation should also be in the range of 20 to 46 cm3/mol. Based on the newly reported factor, we have also designed some new organic cations which may form a 3D HOIPs structure. 相似文献
112.
Swapan Kumar Chandra Partha Chakraborty Animesh Chakravorty 《Journal of Chemical Sciences》1992,104(3):351-360
The reaction of Mn(CH3COO)3 2H2O with the carboxyl-rich ligand pyridine-2,6-dicarboxylic acid (H2L) in methanol affords a high-spin (S = 2) hydratedbis-complex. Structure determination has revealed the solid to be [MnIII(H2 L)(L)] [MnIIIL2] 5H2 O: space group P−1;Z = 2;a = 7.527(3)?3,b= 14.260(4)?,c = 16.080(6)?,α = 91.08(3)°,β = 103.58(3)°,γ= 105.41(3)° andV= 1611.2(10)?3. Each ligand is planar and is bonded in the tridentate O2N fashion. The MnO4N2 coordination spheres show large distortions from octahedral symmetry. The lattice is stabilised by an extensive network of
O…O hydrogen-bonding involving water molecules and carboxyl functions. Upon dissolution in water, protic redistribution occurs
and the complex acts as the mono-basic acid Mn(HL)(L) (pK, 4.3 ±0.05). The deprotonated complex displays high metal reduction potentials: MnIVL2-MnIIIL
2
−
, 1.05V; MnIIIL
2
−
MnIIL
2
2−
-, 0.28V vs. SCE 相似文献
113.
In the context of the dynamical mean-field theory (DMFT) of the Hubbard model, we study the behavior of the compressibility near the density driven Mott transition at finite temperatures. We demonstrate this divergence using DMFT and quantum Monte Carlo simulations in the one-band and the two-band Hubbard model. We supplement this result with considerations based on the Landau theory framework, and discuss the relevance of our results to the alpha-gamma end point in cerium. 相似文献
114.
Animesh Chatterjee 《Journal of sound and vibration》2003,268(4):657-678
Volterra series provides a platform for non-linear response representation and definition of higher order frequency response functions (FRFs). It has been extensively used in non-parametric system identification through measurement of first and higher order FRFs. A parametric system identification approach has been adopted in the present study. The series response structure is explored for parameter estimation of polynomial form non-linearity. First and higher order frequency response functions are extracted from the measured response harmonic amplitudes through recursive iteration. Relationships between higher order FRFs and first order FRF are then employed to estimate the non-linear parameters. Excitation levels are selected for minimum series approximation error and the number of terms in the series is controlled according to convergence requirement. The problem of low signal strength of higher harmonics is investigated and a measurability criterion is proposed for selection of excitation level and range of excitation frequency. The procedure is illustrated through numerical simulation for a Duffing oscillator. Robustness of the estimation procedure in the presence of measurement noise is also investigated. 相似文献
115.
In Tm3+-Ho3+- and Tm3+-Tb3+-doped tellurite glasses, the IR fluorescence spectra and the lifetimes of the upper 3H4 and lower 3F4 lasing levels for 1.47 μm of Tm3+ were measured. The non-exponential decay is fitted using the Inokuti-Hirayama equation. The energy-transfer parameter CDA, critical ion distance R0, lifetime and non-radiative energy-transfer efficiency η between donor and acceptor ions are compared. The quenching mechanism has been explained. Both Ho3+ and Tb3+ ions reduce the lifetimes of the upper and lower lasing levels, with Tb3+ ions proving more efficient than the effects observed for Ho3+ ions. The optimised Tb2O3 concentration is about 1.0-1.5 wt%, which produced effective inversion and could be used for laser and amplifier applications. 相似文献
116.
Animesh Basu 《Meccanica》1988,23(2):121-123
Summary This paper examines temperature distribution and displacement in an infinite elastic solid resulting from the simultaneous application of a thermal disturbance and a small perturbation due to an applied magnetic field. It is shown that the presence of the magneto-thermal coupling factor is to decrease the magnitude of the displacement as well as the magnitude of the temperature distribution. The method of similarly transformations is used for simplification and as a result the governing equations are nondimensionalized automatically. The ISML package for Numerical Inversion of Laplace Transform has been used to confirm the analytical results obtained above. The method is a considerable simplification of that by Paria [Ref. 11] and provides graphs of both displacement and temperature.
Sommario Questo lavoro esamina la distribuzione di temperatura e lo spostamento che, in un solido elastico infinito, risultano dall'applicazione simultanea di un disturbo termico e una piccola perturbazione dovuta ad un campo magnetico applicato. Si dimostra che l'effetto del fattore di accoppiamento magnetotermico è di diminuire l'ampiezza dello spostamento e della variazione di temperatura. Per semplificare si usu il metodo delle trasformazioni di similitudine e di conseguenza le equazioni che reggono il problema risultano automaticamente adimensionali. Si è fatto uso del pacchetto ISML per l'inversione numerica della trasformata di Laplace al fine di confermare i risultati analitici sopra indicati. Il metodo è una sempliflcazione considerevole di quello di Paria (Rif. 11) e fornisce grafici sia dello spostamento sia della temperatura.相似文献
117.
Guar gum, a galactomannan from the seed endosperm of the legume, Cyamopsis tetragonolobus, is an important food stabilizer used in a variety of food products ranging from sauces to ice cream. Two guars having viscosities 13-250% higher than conventional guars were studied. Viscosity, effect of shear rate on viscosity, synergy with xanthan gum, granulation, galactomannan content, molecular weight, and scanning electron microscopy of the guar types were evaluated. At equal usage levels of guar, the high viscosity type showed a higher viscosity alone and in combination with xanthan gum under all conditions tested. The high viscosity products have electron microscopic morphology that is more elongated and molecular weights which are greater than normal guars. These factors are discussed in light of the viscosity differences which exist between these products. 相似文献
118.
119.
Sirin Sahana Chandrakanta Bandyopadhyay Siddhartha Chaudhuri 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1450-1451
The crystal structure of the title compound, C32H24O4, contains three fused dihydropyran rings (A, B and C); ring A is fused with a benzene ring while the other two rings, B and C, are fused with naphthalene rings. Ring A adopts a half‐chair conformation with an equatorial methoxy group, whereas ring B assumes a distorted half‐chair conformation, the A/B ring junction being trans. Ring C adopts a distorted half‐boat conformation and is nearly orthogonal to ring B. Ring C is inclined to the best plane of ring A at an angle of 112.1 (1)°. 相似文献
120.
Trisha Bhattacharya Supratim Ghosh Subhabrata Dutta Dr. Srimanta Guin Animesh Ghosh Prof. Haibo Ge Prof. Raghavan B Sunoj Prof. Debabrata Maiti 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(2):e202310112
The significance of stereoselective C−H bond functionalization thrives on its direct application potential to pharmaceuticals or complex chiral molecule synthesis. Complication arises when there are multiple stereogenic elements such as a center and an axis of chirality to control. Over the years cooperative assistance of multiple chiral ligands has been applied to control only chiral centers. In this work, we harness the essence of cooperative ligand approach to control two different stereogenic elements in the same molecule by atroposelective allylation to synthesize axially chiral biaryls from its racemic precursor. The crucial roles played by chiral phosphoric acid and chiral amino acid ligand in concert helped us to obtain one major stereoisomer out of four distinct possibilities. 相似文献