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排序方式: 共有299条查询结果,搜索用时 15 毫秒
201.
The present study is focused on the evaluation of the interfacial composition, thermodynamic properties, and structural parameters of water-in-oil mixed surfactant microemulsions [(cetylpyridinium chloride, CPC+polyoxyethylene (20) cetyl ether, Brij-58 or polyoxyethylene (20) stearyl ether, Brij-78)/1-pentanol/n-heptane, or n-decane] under various physicochemical environments by the Schulman method of cosurfactant titration of the oil/water interface. The estimation of the number of moles of 1-pentanol at the interface (n(a)(i)) and bulk oil (n(a)(o)) and its distribution between these two domains at the threshold level of stability have been emphasized. The thermodynamics of transfer of 1-pentanol from the continuous oil phase to the interface have been evaluated. n(a)(i),n(a)(i), standard Gibbs free energy (ΔG(t)(0)), standard enthalpy (ΔH(t)(0)), and standard entropy (ΔG(t)(0)) of transfer process have been found to be dependent on the molar ratio of water to surfactant (ω), type of nonionic surfactant and its content (X(Brij-58 or Brij-78)), oil and temperature. A correlation between (ΔH(t)(0)) and (ΔS(t)(0)) is examined at different experimental temperatures. Bulk surfactant composition dependent temperature insensitive microemulsions have been reported. Associated structural parameters, such as droplet dimensions and aggregation number of surfactant and cosurfactant at the droplet interface have been evaluated using a mathematical model after suitable modifications for mixed surfactant systems. In light of these parameters, the prospect of using these microemulsion systems for the synthesis of nanoparticles and the modulation of enzyme activity has been discussed. Correlations of the results in terms of the evaluated physicochemical parameters have been attempted. 相似文献
202.
G. Khatri I. Ciepał K. Bodek N. Kalantar-Nayestanaki St. Kistryn B. Kłos A. Kozela A. Magiera I. Mazumdar J. Messchendorp W. Parol I. Skwira-Chalot E. Stephan D. Rozpędzik A. Wrońska J. Zejma 《Few-Body Systems》2014,55(8-10):1035-1036
An experiment, with the deuteron beams at energy of 160 MeV impinging on the liquid deuterium target, was carried out using the BINA detector at KVI, in Groningen, the Netherlands. Data were collected for the purpose of obtaining high precision differential cross-sections for the deuteron break-up reaction. The elastic scattering channel was also measured alongside for the purpose of cross-section normalization. 相似文献
203.
Recently Yang et al. (Int. J. Theor. Phys. 48:516, 2009) had shown that using a particular type of GHZ- Like state as quantum channel, it is possible to teleport an arbitrary unknown qubit. We investigate this channel for the teleportation of a particular type of two qubit state. 相似文献
204.
205.
A. K. Das M. Datta S. K. Mazumdar N. Das S. K. Talapatra A. P. Sharma A. P. Ollapally G. Bocelli 《Journal of chemical crystallography》1993,23(4):301-303
The present compound crystallizes in the space groupP212121 withZ=4 and cell parametersa=21.687(2),b=8.155(3),c=5.883(2)Å. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value of 0.045 for 1153 observed reflections. The N-glycosidic torsion angle CN is in the anti-range and the pyranosyl ring adopts a distorted half-chair conformation with 2=142.7(4)°,
2=124.4(3)° andQ=0.456(2)Å. In the crystal packing the molecules are linked together by N-HO hydrogen bonds and C-HO contacts. 相似文献
206.
Bidyut Santra Bhabani S. Dandapat 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,80(11):688-700
A thin viscous liquid film flow is developed over a stretching sheet under different nonlinear stretching velocities. An evolution
equation for the film thickness, is derived using long-wave approximation of thin liquid film and is solved numerically by
using the Newton–Kantorovich method. A comparison is made with the analytic solution obtained in [B. S. Dandapat, A. Kitamura,
B. Santra, “Transient film profile of thin liquid film flow on a stretching surface”, ZAMP, 57, 623-635 (2006)]. It is observed that all types of stretching produce film thinning but non-monotonic stretching produces
faster thinning at small distance from the origin. The velocity u along the stretching direction strongly depends on the distance along the stretching direction and the Froude number. 相似文献
207.
In this paper we study the asymptotics of the tail of the buffer occupancy distribution in buffers accessed by a large number of stationary independent sources and which are served according to a strict HOL priority rule. As in the case of single buffers, the results are valid for a very general class of sources which include long-range dependent sources with bounded instantaneous rates. We first consider the case of two buffers with one of them having strict priority over the other and we obtain asymptotic upper bound for the buffer tail probability for lower priority buffer. We discuss the conditions to have asymptotic equivalents. The asymptotics are studied in terms of a scaling parameter which reflects the server speed, buffer level and the number of sources in such a way that the ratios remain constant. The results are then generalized to the case of M buffers which leads to the source pooling idea. We conclude with numerical validation of our formulae against simulations which show that the asymptotic bounds are tight. We also show that the commonly suggested reduced service rate approximation can give extremely low estimates. 相似文献
208.
D. Mazumdar P.A. Govindacharyulu D.N. Bose 《Journal of Physics and Chemistry of Solids》1982,43(9):933-940
A Study of electronic conductivity using the d.c. polarization technique has been carried out in α and β-AgI which shows the former is a hole and the latter an electron conductor. Activation energies of undoped and Cu-doped single crystals and polycrystalline β-AgI were found to be 0.46 eV, 0.34 eV and 0.44 eV respectively and can be related to electron trap depths. The electron transference number () for polycrystalline β-AgI was found to be 0.008 at 306 K. The activation energy for hole conduction in α-AgI was determined to be 0.97 eV in agreement with previous XPS studies.Transient measurements have also been conducted using the charge transfer technique in double cells of polycrystalline β-AgI. The carrier concentration Cθ and electron mobility μθ, have thus been estimated to be 1.8 × and 5.14 × 10?5?sec. respectively at 306 K, while the double layer capacitance was 0.496 . 相似文献
209.
A method for the time history of motion of shallow shells of viscoelastic material under arbitrary time-dependent transverse load is presented. The method is based upon the concept of iso-amplitude contour lines on the surface of the shell. It is shown that the time behavior can be found by using the frequency of free vibration of the associated elastic shallow shell. As an illustration of the technique, the problem of a shallow dome upon an elliptic base is discussed, all details of which are explained by graphs. 相似文献
210.