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排序方式: 共有166条查询结果,搜索用时 15 毫秒
41.
Rupali Gangopadhyay 《Journal of Polymer Science.Polymer Physics》2008,46(22):2443-2455
Stable aqueous dispersion of polyaniline (PAn) stabilized by a hydrophilic polymer poly(vinyl pyrrolidone) (PVP) exhibits interesting rheological properties different from its components. Shear thinning observed for both PVP and PAn–PVP colloid (PP) indicates partially entangled nature of the later. Linear viscoelastic response of PVP solution exhibit strong frequency dependence of elastic (G′) and viscous (G″) modulus over the whole frequency range (0.1–100 ras/s) where G′ never exceeds G″ indicating the applicability of the Rouse‐Zimm model to this system. On the other hand, there is a crossover of G′ and G″ in the rheological profile of PP dispersion so that a single relaxation time model can be applicable. Therefore, PVP presents an entangled polymeric system and supposed to have a spectrum of relaxation times, whereas PP resembles to a physically crosslinked system with a single relaxation time. Increasing the extent of hydrogen bonding within the system (by raising the fraction of PAn or by leaving the solution undisturbed for long) relaxation time also becomes longer. The large difference in values of steady and complex shear viscosity (η and η*) within LVE regime reflects that original Cox‐Merz rule is obviously inapplicable to these systems. But at larger strain amplitude, η and η* are satisfactorily coincident that indicates a broader applicability of the modified Cox‐Merz rule. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2443–2455, 2008 相似文献
42.
Micellar solution of nonionic surfactantn-dodecyloligo ethyleneoxide surfactant, decaoxyethylene monododecyl ether [CH3(CH2)11(OCH2CH2)10OH], C12E10 in D2O solution have been analysed by small-angle neutron scattering (SANS) at different temperatures (30, 45 and 60° C) both in
the presence and absence of sugars. The structural parameters like micelle shape and size, aggregation number and micellar
density have been determined. It is found that the micellar structure significantly depends on the temperature and concentration
of sugars. The micelles are found to be prolate ellipsoids at 30° C and the axial ratio of the micelle increases with the
increase in temperature. The presence of lower concentration of sugar reduces the size of micelles and it grows at higher
concentration of sugar. The structure of micelles is almost independent of the different types of sugars used. 相似文献
43.
D. P. Bhattacharyya S. Chakrabarty R. Rakshit B. Basu Pratibha Pal S. Biswas 《Il Nuovo Cimento C》1993,16(3):249-254
Summary A stack consisting of CR-39(DOP) detector with 2.6 cm Al target was exposed to a238U beam of energy 0.927 GeV/n from LBL BEVALAC to study the large-fragmentation phenomena during U+Al interaction. The diameter
distribution of the etch pits formed in the plastic detectors for the first three projectile fragments of chargeZ
F≥89 yields the partial cross-section data which is comparable to the data obtained from the cone length distribution. The
present result on the partial cross-section is significantly higher than those expected from the abrasion-ablation model of
Wilson, Townsed and Badavi (1987).
The authors of this paper have agreed not to receive the proofs for correction. 相似文献
44.
Rajeeb Dey Sandip Ghosh G. Ray A. Rakshit 《Numerical Linear Algebra with Applications》2011,18(3):351-361
A nonlinear matrix inequality is derived as a stabilizability condition of linear uncertain time‐delay systems. This inequality is seen as a less conservative one as well as efficient for numerical computation than the existing results as seen when solving by cone‐complementary algorithm. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
45.
Abhishek RoyChowdhury Pallabi Mukherjee Saumik Panja Rupali Datta Christos Christodoulatos Dibyendu Sarkar 《Molecules (Basel, Switzerland)》2021,26(1)
The use of insensitive munitions such as 3-nitro-1,2,4-triazol-5-one (NTO) is rapidly increasing and is expected to replace conventional munitions in the near future. Various NTO treatment technologies are being developed for the treatment of wastewater from industrial munition facilities. This is the first study to explore the potential phytoremediation of industrial NTO-wastewater using vetiver grass (Chrysopogon zizanioides L.). Here, we present evidence that vetiver can effectively remove NTO from wastewater, and also translocated NTO from root to shoot. NTO was phytotoxic and resulted in a loss of plant biomass and chlorophyll. The metabolomic analysis showed significant differences between treated and control samples, with the upregulation of specific pathways such as glycerophosphate metabolism and amino acid metabolism, providing a glimpse into the stress alleviation strategy of vetiver. One of the mechanisms of NTO stress reduction was the excretion of solid crystals. Scanning electron microscopy (SEM), electrospray ionization mass spectrometry (ESI-MS), and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the presence of NTO crystals in the plant exudates. Further characterization of the exudates is in progress to ascertain the purity of these crystals, and if vetiver could be used for phytomining NTO from industrial wastewater. 相似文献
46.
H. E. Annet R. R. Sanghi und J. N. Rakshit 《Fresenius' Journal of Analytical Chemistry》1927,71(7):250-251
Ohne Zusammenfassung 相似文献
47.
Marianne?P.?Rodgers Christopher?C.?Rodgers Animesh?K.?Rakshit Rama?M.?PalepuEmail author 《Colloid and polymer science》2003,281(8):800-805
The effects of the addition of several propylene glycol oligomer additives on the micellar properties of the cationic mixed micelle system of cetyltrimethylammonium bromide (CTAB) and tetradecyltrimethylammonium bromide (TTAB) were investigated. Through conductivity studies, the critical micelle concentration (cmc) and counter-ion binding values were observed in the presence of the additives. A regular solution approach was employed to determine the effects of the additives on the interactions between the two surfactants to form the mixed micelles. The effects of the additives on the interaction parameter and the composition of the mixed micelles were evaluated. Excess Gibbs energy of mixing and the values of activity coefficients were also calculated and described in terms of non-ideality of the system. 相似文献
48.
5-Bromosalicylalcohol was prepared by the interaction of NaBH4 and 5-bromosalicylaldehyde. The use of sodium borohydride makes the reaction easy, facile, economic and does not require any toxic catalyst. The compound is characterized by FTIR, 1H NMR, 13C NMR, TEM and ESI-mass spectra. Crystal structure is determined by single crystal X-ray analysis. Quantum mechanical calculations of geometries, energies and thermodynamic parameters are carried out using density functional theory (DFT/B3LYP) method with 6-311G(d,p) basis set. The optimized geometrical parameters obtained by B3LYP method show good agreement with experimental data. 相似文献
49.
Pawar Rupali R. Suryavanshi Vishal J. Salunkhe Suresh T. Patil Suresh S. Mulik Ganpatrao N. 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(1):419-426
The extraction behavior of thorium(IV) from sulphuric acid medium with N-n-heptylaniline in xylene. Various parameters like reagent concentration, acid concentration, equilibration time, diverse ions and effect of diluents were studied. Thorium(IV) was selectively extracted and separated from many metal ions. The nature of the extracted species was determined. Thorium(IV) was analyzed from monazite ore and gas mantle.
相似文献50.