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排序方式: 共有3292条查询结果,搜索用时 78 毫秒
1.
Satyanarayana A. V. S. Rao M. Jagannadha Mouli K. Chandra 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(3):1509-1513
Journal of Radioanalytical and Nuclear Chemistry - 相似文献
2.
Rajiv Manohar G. Tripathi A.K. Srivastava A.K. Prajapati 《Journal of Physics and Chemistry of Solids》2006,67(11):2300-2304
Dielectric properties of polymer-liquid crystal mixture, having constituent polymer, poly-butyl methacrylate (PBMA) and liquid crystal, cholesteryl nonanoate, are reported as a function of frequency and temperature. The measurement has been done in a temperature range of 300-375 K and frequency range of 100 Hz-10 MHz. The dielectric permittivity and dielectric loss shows significant changes with the addition of polymer molecules in liquid crystal. The significant feature of composite formation is that the pure liquid crystal and polymer do not show dielectric relaxation in the frequency range covered, while the composite shows relaxation peak at a particular frequency. The optical transmittance of pure liquid crystal and composite has also been measured and compared. 相似文献
3.
4.
Present paper deals with the structural, magnetic and transport studies of as-deposited as well as annealed Co/GaAs(0 0 1) thin film at different temperatures. The X-ray diffraction measurements show oriented growth of as-deposited Co film in the hcp (0 0 2) direction. However, the sample annealed at higher temperatures shows formation of ternary Co2GaAs phase at the interface. Corresponding magnetic and transport measurements show decrement in magnetization and resistivity with annealing temperatures. The observed reductions in magnetization and resistivity values are mainly attributed to the formation of ternary Co2GaAs phase at the interface. 相似文献
5.
V Ravindran Pankaj Agrawal Rahul Basu Satyaki Bhattacharya J Blümlein V Del Duca R Harlander D Kosower Prakash Mathews Anurag Tripathi 《Pramana》2006,67(5):983-992
This is the report of the subgroup QCD of Working Group-4 at WHEPP-9. We present the activities that had taken place in the
subgroup and report some of the partial results arrived at following the discussion at the working group meetings. 相似文献
6.
Vandana Singh Ashutosh TiwariDevendra Narayan Tripathi Tulika Malviya 《Tetrahedron letters》2003,44(39):7295-7297
O-Methylation is of outstanding importance in structural polysaccharide chemistry. A novel method for the methylation of polysaccharides using microwave (MW) irradiation is described. Seed gum from Cyamopsis tetragonolobus (Guar) was fully methylated with dimethyl sulphate and sodium hydroxide using 100% microwave power for 4 min in 68% yield. The completely methylated seed gum thus obtained was hydrolyzed by 70% formic acid followed by 0.5N H2SO4 under full microwave power for 1.16 and 1.66 min, respectively. The partially methylated monosaccharides were separated and identified. 相似文献
7.
8.
The present paper reports the dislocation unpinning model of acoustic emission (AE) from alkali halide crystals. Equations
are derived for the strain dependence of the transient AE pulse rate, peak value of the AE pulse rate and the total number
of AE pulse emitted. It is found that the AE pulse rate should be maximum for a particular strain of the crystals. The peak
value of the AE pulse rate should depend on the volume and strain rate of the crystals, and also on the pinning time of dislocations.
Since the pinning time of dislocations decreases with increasing strain rate, the AE pulse rate should be weakly dependent
on the strain rate of the crystals. The total number of AE should increase linearly with deformation and then it should attain
a saturation value for the large deformation. By measuring the strain dependence of the AE pulse rate at a fixed strain rate,
the time constantτ
s for surface annihilation of dislocations and the pinning timeτ
p of the dislocations can be determined. A good agreement is found between the theoretical and experimental results related
to the AE from alkali halide crystals. 相似文献
9.
René Meziat Diego Patiño Pablo Pedregal 《Computational Optimization and Applications》2007,38(1):147-171
We propose an alternative method for computing effectively the solution of non-linear, fixed-terminal-time, optimal control
problems when they are given in Lagrange, Bolza or Mayer forms. This method works well when the nonlinearities in the control
variable can be expressed as polynomials. The essential of this proposal is the transformation of a non-linear, non-convex
optimal control problem into an equivalent optimal control problem with linear and convex structure. The method is based on
global optimization of polynomials by the method of moments. With this method we can determine either the existence or lacking
of minimizers. In addition, we can calculate generalized solutions when the original problem lacks of minimizers. We also
present the numerical schemes to solve several examples arising in science and technology. 相似文献
10.
Considering external electric field as well as third- and fourth-order phonon anharmonic interaction terms in the pseudospin-lattice
coupled mode (PLCM) model Hamiltonian for KDP-type ferroelectrics, expressions for field-dependent shift, width, renormalized
soft mode frequency, Curie temperature, dielectric constant and dielectric loss are evaluated. For the calculation, method
of statistical double-time temperature-dependent Green’s function has been used. By fitting model values of physical quantities,
temperature and electric field dependences of soft mode frequency, dielectric constant and loss have been calculated which
compare well with experimental results of Baumgartner [8] and Choi and Lockwood [9]. Both dielectric constant and loss decrease
with electric field. 相似文献