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191.
The growth rate of the partial maximum of a stationary stable process was first studied in the works of Samorodnitsky (Ann. Probab. 32:1438–1468, 2004; Adv. Appl. Probab. 36:805–823, 2004), where it was established, based on the seminal works of Rosiński (Ann. Probab. 23:1163–1187, 1995; 28:1797–1813, 2000), that the growth rate is connected to the ergodic-theoretic properties of the flow that generates the process. The results were generalized to the case of stable random fields indexed by ? d in Roy and Samorodnitsky (J. Theor. Probab. 21:212–233, 2008), where properties of the group of nonsingular transformations generating the stable process were studied as an attempt to understand the growth rate of the partial maximum process. This work generalizes this connection between stable random fields and group theory to the continuous parameter case, that is, to fields indexed by ? d . 相似文献
192.
Debasis De Shanker Ram Alok BanerjeeSanat K. Roy 《Journal of magnetism and magnetic materials》2012,324(6):1133-1140
(La0.6Eu0.4)0.67Ca0.33MnO3 has been prepared in the shape of nanoplates of single crystallites (an orthorhombic structure) through polymer templates. HRTEM images reveal 18, 25, and 30 nm thicknesses of plates after heating a precursor powder at 873, 1073, and 1273 K in air for 2 h. These values present average crystallite size determined from broadening of the X-ray diffraction peaks. A spin-glass-like surface (GS) overlayer (3-5 nm thickness) in such plates facilitates a ferromagnetic→ferrimagnetic reordering with markedly suppressed Curie point TC, i.e., as small as 90 K in a 873 K heated sample, from the parent value 268 K. The TC point increases to 103 K (or 120 K) when heating at higher temperature 1073 (or 1273 K), during which the core grows at the expense of the overlayer. The GS tailors as high coercivity Hc as 617 Oe in the zero field cooled (ZFC) sample that is decreased to 500 Oe in the field cooled (FC) sample in the surface spin-freezing along the field direction. The Hc-value (ZFC) that steps down successively to 252 Oe on the overlayer is thinned down by heating at 1273 K. Samples heated at 873, 1073, or 1273 K have regularly increased saturation magnetization 35.3, 63.9, or 69.6 emu/g in ZFC, while 43.7, 70.2, or 75.5 emu/g in FC measured at 10 K. The ferrimagnetic reordering are described based on the scenario of an antiferromagnetic exchange coupling between the Eu3+ and Mn3+ (or Mn4+) sublattices. 相似文献
193.
194.
Arijit Chakrabarty 《Stochastic Processes and their Applications》2012,122(2):623-653
This paper studies the effect of truncation on the large deviations behavior of the partial sum of a triangular array coming from a truncated power law model. Each row of the triangular array consists of i.i.d. random vectors, whose distribution matches a power law on a ball of radius going to infinity, and outside that it has a light-tailed modification. The random vectors are assumed to be Rd-valued. It turns out that there are two regimes depending on the growth rate of the truncating threshold, so that in one regime, much of the heavy tailedness is retained, while in the other regime, the same is lost. 相似文献
195.
Alok Srivastava B. S. Bhadauria P. G. Siddheshwar I. Hashim 《Transport in Porous Media》2013,99(2):359-376
Thermo-rheological effect of temperature-dependent viscous fluid saturating a porous medium has been studied in the presence of imposed time periodic gravity field and internal heat source. Weak nonlinear stability analysis has been performed by using the power series expansion in terms of the amplitude of gravity modulation, which is considered to be small. Nusselt number is calculated numerically using Ginzburg–Landau equation. The nonlinear effects of thermo-mechanical anisotropies, internal heat source parameter, Vadász number, thermo-rheological parameter and amplitude of gravity modulation have been obtained and depicted graphically. Streamlines and isotherms have been drawn for different times. Comparisons have been made between various physical systems. 相似文献
196.
In this paper we try to understand several phenomenological issues related to the mass spectra of P-states quarkonia in a relativistic quark model. We give particular emphasis on understanding the most recent experimental
data within a relativized scalar-vector confining potential. In this paper we extend the previous works on the studies of
quark confinement in non-relativistic QCD, using a formalism which uses a covariant Hamiltonian in the centre of mass frame.
The spin-structure of the potential is obtained from the reduction of Bethe-Salpeter equation into Breit-interaction.
Printed as S Chakrabarty in several papers published earlier e.g. References [1,11] etc. of this paper. 相似文献
197.
Manas Chakrabarty Sulakshana Karmakar Ratna Mukherjee Shiho Arima Yoshihiro Harigaya 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):375-380
Abstract 1-Alkyl/phenyl-2-arylbenzimidazoles have been synthesized in very good to excellent yields by a one-pot condensation of N-alkyl/phenyl-o-phenylenediamines with aryl aldehydes in water at room temperature using cetylpyridinium bromide as a cheap and eco-friendly
catalyst.
Graphical abstract
相似文献
198.
Rapid Screening and Isolation of a Fungus for Sitosterol to Androstenedione Biotransformation 总被引:1,自引:0,他引:1
Androstenedione (AD) is a steroid intermediate used in the pharmaceutical industry for the production of several important
anabolic drugs. An important route for producing AD is by the microbial transformation of sterols. Microbes capable of efficiently
transforming sterols to AD are few and newer strains need to be isolated. Conventional procedures for screening and isolation
are time consuming. A new procedure was used for screening and isolation of fungal microorganisms capable of biotransformation
of sitosterol to androstenedione. In this procedure, Basic Alignment Search Tool (BLAST) and Position-Specific Iterative BLAST
were employed to obtain a parent set of candidate microorganisms. The parent set was reduced using heuristics and constraints
to obtain a manageable number of microorganisms that may be tested experimentally. For this work, screening of the entire
NCBI database yielded a parent set containing 64 microorganisms. Among these, only two microorganisms, Aspergillus oryzae and Aspergillus nidulans FGSC A4, qualified to the experimental stage. Sitosterol biotransformation experiments were carried out using A. oryzae and the production of AD in culture medium was confirmed. 相似文献
199.
Extraction and recovery of lignosulfonate from its aqueous solution using bulk liquid membrane 总被引:2,自引:2,他引:0
Kabita Chakrabarty K. Vamsee Krishna Prabirkumar Saha Aloke Kumar Ghoshal 《Journal of membrane science》2009,330(1-2):135-144
The paper presents an experimental study on the coupled transport of lignosulfonate (LS) through bulk liquid membrane (BLM) and thereby to identify the best set of solvent, operating conditions and mode of transport that would yield optimum performance of the BLM. Trioctylamine (TOA) is used as carrier. Among various solvents, tested for the above purpose, dichloroethane is found to be the best. The effects of operating condition, viz. pH, temperature, and carrier concentration, on the equilibrium distribution of LS are investigated. The effects of temperature, stirring of aqueous and organic phases, stirring speed, carrier concentration, initial feed and strip phase concentration on the separation of LS using BLM are also studied. It is observed that transport of LS can be enhanced by increasing the temperature and stirring speed of feed phase. Stirring of strip phase has no appreciable effects on the transport of LS. With increase in initial feed concentration the initial rate of the transport of LS is higher but continues for a longer time. Recovery of LS is much higher in co-transport mode in comparison to counter transport mode. Application of 1.25 M NaOH as stripping solution gives high recovery (70%) and high strip flux (70% of feed flux). 相似文献
200.
Srivastava Alok Swain Kallola K. Chahar Vikas Bhardwaj Sonakshi Ajith Nicy Mete Uttam Garg Uttam Srivastava Tarak 《Journal of Radioanalytical and Nuclear Chemistry》2019,319(1):271-278
Twenty eight stones were characterized for chemical composition and structure. The concentrations of trace elements were determined using INAA while EDXRF was used for determining the calcium contents of the stones. Twenty stones were found to be mainly composed of calcium, six were mixed type and the remaining two were of uric acid type. The concentrations of trace elements namely Zn, Sr, Fe and Cr were lower in uric acid stones as compared to calcium based stones. Diet analysis of 310 patients who were treated for renal stones showed a diet rich in calcium and oxalate and decreased water consumption.
相似文献