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81.
Hellar Nithya S. Selvasekarapandian P. Christopher Selvin Dorai Arun Kumar Muthusamy Hema 《Ionics》2011,17(7):587-593
The plasticized polymer electrolyte consisting of poly(epichlorohydrin-ethyleneoxide) [P(ECH-EO)], lithium perchlorate (LiClO4) and γ-butyrolactone (γ-BL) have been prepared by simple solution casting technique. The polymer–salt–plasticizer complex
has been confirmed by XRD analysis. The ionic conductivity studies have been carried out using AC impedance technique. The
effect of plasticizer (γ-BL) on ionic conductivity has been discussed with respect to different temperatures. The maximum
value of ionic conductivity is found to be 1.3 × 10−4 Scm−1 for 70P(ECH-EO):15γ-BL:15LiClO4 at 303 K. The temperature dependence of the plasticized polymer electrolyte follows the Vogel–Tamman–Fulcher formalism. The
activation energy is found to decrease with the increase in plasticizer. 相似文献
82.
Abstract Ten lanthanide complexes (Ln=La, Ce, Pr, Nd, Sm, Gd, Eu and Dy) with the title ligands have been synthesised and characterised. The structure of these complexes are assigned on the basis of IR spectra, magnetic and thermal analysis data. The IR spectra indicate that o-vanillin paraanisidine (oVPA) is a bidentate ligand coordinating through azomethine N and phenolic O whereas o-vanillin salicyloylhydrazone (oVSH) is tridentate possessing ketonic O as an additional donor site. Involvement of anions (Cl?, Ac?) in coordination is explored. Electronic spectra indicate weak covalent nature of metal ligand bond and various parameters β, b½, η and δ have been evaluated. 相似文献
83.
Kavita Srivastava Anke Jentsch Juergen Kreyling Bruno Glaser Guido L. B. Wiesenberg 《Isotopes in environmental and health studies》2018,54(1):41-62
Temperate ecosystems are susceptible to drought events. The effect of a severe drought (104 days) followed by irrigation on the plant C uptake, its assimilation and input of C in soil were examined using a triple 13CO2 pulse-chase labelling experiment in model grassland and heathland ecosystems. First 13CO2 pulse at day 0 of the experiment revealed much higher 13C tracer uptake for shoots, roots and soil compared to the second pulse (day 44), where all plants showed significantly lower 13C tracer uptake. After the third 13CO2 pulse (day 70), very low 13C uptake in shoots led to a negligible allocation of 13C into roots and soil. During irrigation after the severe drought, the 13C tracer that was allocated in plant tissues during the second and third pulse labelling was re-allocated in roots and soil, as soon as the irrigation started. This re-allocation was higher and longer lasting in heathland compared to grassland ecosystems. 相似文献
84.
Kavita Jain 《Pramana》2008,71(2):275-282
We study the adaptation dynamics of an initially maladapted population evolving via the elementary processes of mutation and
selection. The evolution occurs on rugged fitness landscapes which are defined on the multi-dimensional genotypic space and
have many local peaks separated by low fitness valleys. We mainly focus on the Eigen’s model that describes the deterministic
dynamics of an infinite number of self-replicating molecules. In the stationary state, for small mutation rates such a population
forms a quasispecies which consists of the fittest genotype and its closely related mutants. The quasispecies dynamics on
rugged fitness landscape follow a punctuated (or steplike) pattern in which a population jumps from a low fitness peak to
a higher one, stays there for a considerable time before shifting the peak again and eventually reaches the global maximum
of the fitness landscape. We calculate exactly several properties of this dynamical process within a simplified version of
the quasispecies model.
相似文献
85.
Density functional molecular dynamical simulations have been performed on Ga17 and Ga13 clusters to understand the recently observed higher-than-bulk melting temperatures in small gallium clusters [Phys. Rev. Lett. 91, 215508 (2003)]]. The specific-heat curve, calculated with the multiple-histogram technique, shows the melting temperature to be well above the bulk melting point of 303 K, viz., around 650 and 1400 K for Ga17 and Ga13, respectively. The higher-than-bulk melting temperatures are attributed mainly to the covalent bonding in these clusters, in contrast with the covalent-metallic bonding in the bulk. 相似文献
86.
A versatile green and nontoxic begin method for bio-reduction of silver nanoparticles (AgNPs) using latex extract of Ipomea carnea was reported. Different instrumental tools were applied to evaluate the formation of AgNPs, as an example UV–Visible spectroscopy (UV–Vis), Fourier transform infra-red (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM). The absorption peak of AgNPs obtained at around 413 nm. FTIR study confirmed that the bio-capping components present in latex extract served as reducing and stabilizing agent. The findings of XRD, SEM and HR-TEM images revealed that the formation of crystalline and spherical shape nanoparticles and showed well size distribution with mean size 9.8±0.27 nm. Additionally, the green fabricated AgNPs exhibited considerable zone of inhibition for both Gram-positive and Gram–negative bacteria. The outcome implies that the synthesized AgNPs also showed similar inhibition effect as streptomycin (a common reference antibiotic). 相似文献
87.
Kalicharan Chattopadhyay Anil Yadav Dheer Singh Anju Chopra Kavita Rai J. N. Pandey V. Kagdiyal D. Saxena 《Chromatographia》2017,80(1):145-150
A two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC–TOFMS) method was developed for the hydrocarbon class composition analysis and benzene, toluene, ethylbenzene, and xylene (BTEX) estimation of raffinate column bottom (RCB), which is generated as a by-product from linear alkyl benzene (LAB) plants. The molecular level characterization of RCB is important to generate value-added products for the petrochemical industry. GC×GC–TOFMS was found to be an excellent tool for estimation of hydrocarbon class composition (paraffins, naphthenes, monoaromatics, diaromatics, and polyaromatic hydrocarbons) and trace level BTEX in a single run. The hydrocarbon class composition was validated with the standard method based on HPLC (ASTM D6591) and good correlation was obtained. Finally, RCB is anticipated to be a useful nonhazardous safe by-product which could be used further for generating added value. 相似文献
88.
We study a symmetric exclusion process in which the hopping rates at two chosen adjacent sites vary periodically in time and have a relative phase difference. This mimics a colloidal suspension subjected to external time-dependent modulation of the local chemical potential. The two special sites act as a classical pump by generating an oscillatory current with a nonzero dc value whose direction depends on the applied phase difference. We analyze various features in this model through simulations and obtain an expression for the dc current via a novel perturbative treatment. 相似文献
89.
Krishnamurty S Joshi K Zorriasatein S Kanhere DG 《The Journal of chemical physics》2007,127(5):054308
Recent experimental results have reported surprising variations in the shapes of the heat capacity curves and melting temperatures of gallium clusters in the size range of 30-55 atoms [G. A. Breaux et al., J. Am. Chem. Soc. 126, 8628 (2004)]. In the present work, we have carried out an extensive density functional investigation on ten selected clusters in the above mentioned size range. In particular, we have analyzed the ground state geometry and the nature of bonding in these clusters using electron localization function. We demonstrate that the existence or otherwise of a large island of atoms bonded with similar strength (i.e., the local order) in the ground state geometry is responsible for the variation in the shape of the heat capacity curve. We attribute the observed higher melting temperatures of some of the clusters (viz., Ga45-Ga48) to the presence of a distinct core and strong covalent bonds between the core and surface atoms. The present work clearly demonstrates that it is possible to understand the general trends observed in the heat capacity curves across the entire series on the basis of the analysis of their ground state. 相似文献
90.
Double stranded calf thymus deoxyribonucleic acid entrapped polypyrrole-polyvinyl sulphonate (dsCT-DNA-PPy-PVS) films fabricated onto indium-tin-oxide (ITO) coated glass plates have been used to detect organophosphates such as chlorpyrifos and malathion. These disposable dsCT-DNA-PPy-PVS/ITO bioelectrodes have been characterized using cyclic voltammetry, Fourier-transform-infra-red (FTIR) spectroscopy and atomic force microscopy (AFM), respectively. These biosensing electrodes have a response time of 30 s, are stable for about 5 months when stored in desiccated conditions at 25 °C and can be used to amperometrically detect chlorpyrifos (0.0016-0.025 ppm) and malathion (0.17-5.0), respectively. The additive effect of these pesticides on the amperometric response of the disposable dsCT-DNA-PPy-PVS/ITO bioelectrodes has also been investigated. 相似文献