排序方式: 共有141条查询结果,搜索用时 31 毫秒
11.
In the current communication, the problem of plane wave diffraction by a conductible plate of finite length in the presence of cold plasma is investigated. The boundary-value problem corresponding to this model is formulated by Fourier transform which then leads to the Wiener?Hopf equation. The resulting equation has been solved by the Wiener?Hopf procedure in a standard way. The separated field (diffracted field) is analyzed in an anisotropic medium using asymptotic expansion and modified stationary phase method. The problem can be made simple by assuming ε2→0, where ε2 is the element of permittivity tensor. This happens, if the operating frequency is assumed to be very large as compared to ωc (cyclotron frequency) while it is of same order of ωp (the plasma frequency). The case ε1 =1, ε2→0 leads to the results for soft plate of finite length in an isotropic medium. Graphical study is performed to investigate the behavior of separated field for various physical parameters for isotropic and anisotropic media. 相似文献
12.
Lithium‐Salt‐Containing High‐Molecular‐Weight Polystyrene‐block‐Polyethylene Oxide Block Copolymer Films
下载免费PDF全文
![点击此处可从《Chemphyschem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Ezzeldin Metwalli Majid Rasool Simon Brunner Prof. Dr. Peter Müller‐Buschbaum 《Chemphyschem》2015,16(13):2882-2889
Ionic conductivity in relation to the morphology of lithium‐doped high‐molecular‐weight polystyrene‐block‐polyethylene oxide (PS‐b‐PEO) diblock copolymer films was investigated as solid‐state membranes for lithium‐ion batteries. The tendency of the polyethylene (PEO) block to crystallize was highly suppressed by increasing both the salt‐doping level and the temperature. The PEO crystallites completely vanished at a salt‐doping ratio of Li/EO>0.08, at which the PEO segments were hindered from entering the crystalline unit of the PEO chain. A kinetically trapped lamella morphology of PS‐b‐PEO was observed, due to PEO crystallization. The increase in the lamella spacing with increasing salt concentration was attributed to the conformation of the PEO chain rather than the volume contribution of the salt or the previously reported increase in the effective interaction parameter. Upon loading the salt, the PEO chains changed from a compact/highly folded conformation to an amorphous/expanded‐like conformation. The ionic conductivity was enhanced by amorphization of PEO and thereby the mobility of the PEO blocks increased upon increasing the salt‐doping level. 相似文献
13.
14.
Khan SA Nishat N Parveen S Rasool R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,81(1):290-295
A novel tetradentate salicylic acid-formaldehyde ligand containing piperazine moiety (SFP) was synthesized by condensation of salicylic acid, formaldehyde and piperazine in presence of base catalyst, which was subjected for the preparation of coordination polymers with metal ions like manganese(II), cobalt(II), copper(II), nickel(II) and zinc(II). All the synthesized polymeric compounds were characterized by elemental analysis, IR, (1)H NMR and electronic spectral studies. The thermal stability was determined by thermogravimetric analysis and thermal data revealed that all the polymer metal complexes show good thermal stability than their parent ligand. Electronic spectral data and magnetic moment values revealed that polymer metal complexes of Mn(II), Co(II) and Ni(II) show an octahedral geometry while Cu(II) and Zn(II) show distorted octahedral and tetrahedral geometry respectively. The antimicrobial screening of the ligand and coordination polymers was done by using Agar well diffusion method against various bacteria and fungi. It was evident from the data that antibacterial and antifungal activity increased on chelation and all the polymer metal complexes show excellent antimicrobial activity than their parent ligand. 相似文献
15.
Farzali Izadi Naghdali Forooshani Rasool Amiryousefi Varnousfaderani Amaneh 《Proceedings Mathematical Sciences》2018,128(2):18
In this paper, we examine a class of fourth power diophantine equations of the form \(x^4+kx^2y^2+y^4=z^2\) and \(ax^4+by^4=cz^2\), in the Gaussian integers, where a and b are prime integers. 相似文献
16.
Farzad Zamani Rasool Babaahmadi Brian F. Yates Michael G. Gardiner Alireza Ariafard Stephen G. Pyne Christopher J. T. Hyland 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(7):2136-2141
A synthesis of unconjugated (E)‐enediynes from allenyl amino alcohols is reported and their gold‐catalyzed cascade cycloaromatization to a broad range of enantioenriched substituted isoindolinones has been developed. Experimental and computational studies support the reaction proceeding via a dual‐gold σ,π‐activation mode, involving a key gold‐vinylidene‐ and allenyl‐gold‐containing intermediate. 相似文献
17.
18.
Ahmad VU Arshad S Bader S Iqbal S Khan A Khan SS Hussain J Tareen RB Ahmed A 《Magnetic resonance in chemistry : MRC》2008,46(10):986-989
Two new triterpenoidal saponins were isolated from the n-butanolic extract of Stachys parviflora (Lamiaceae). Their structures were elucidated on the basis of spectral data as stachyssaponin A; 3beta, 15alpha, 19alpha, 21beta, 22alpha-pentahydroxyolean-12-ene-28-oic acid 3-O-{alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranoside}-22-O-{alpha-L-arabinofuranosyl-(1 --> 3)-beta-D-glucopyranoside} (1) and stachyssaponin B; 2beta, 3beta, 15alpha, 21beta-tetrahydroxyolean-12-ene-28-oic acid 2-O-[alpha-L-arabinofuranoside]-3, 21-bis-O-[beta-D-glucopyranoside] (2). 相似文献
19.
20.
Ravi P. Agarwal Fatemah Mofarreh Rasool Shah Waewta Luangboon Kamsing Nonlaopon 《Entropy (Basel, Switzerland)》2021,23(8)
This research article is dedicated to solving fractional-order parabolic equations using an innovative analytical technique. The Adomian decomposition method is well supported by natural transform to establish closed form solutions for targeted problems. The procedure is simple, attractive and is preferred over other methods because it provides a closed form solution for the given problems. The solution graphs are plotted for both integer and fractional-order, which shows that the obtained results are in good contact with the exact solution of the problems. It is also observed that the solution of fractional-order problems are convergent to the solution of integer-order problem. In conclusion, the current technique is an accurate and straightforward approximate method that can be applied to solve other fractional-order partial differential equations. 相似文献