http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Sat, 18 May 2013 09:58:11 +0000 http://www.hindawi.com/journals/ijem/2013/612472/ The perturbed systems of sines, which appear when solving some partial differential equations by the Fourier method, are considered in this paper. Basis properties of these systems in weighted Sobolev spaces of functions are studied. V. F. Salmanov and A. R. Safarova Copyright © 2013 V. F. Salmanov and A. R. Safarova. All rights reserved. Thu, 16 May 2013 13:15:59 +0000 http://www.hindawi.com/journals/ijem/2013/746910/ We established -expansion method for (2+1)-dimensional nonlinear evolution equations. This method was used to construct travelling wave solutions of (2+1)-dimensional nonlinear evolution equations. (2+1)-Dimensional breaking soliton equation, (2+1)-dimensional Calogero-Bogoyavlenskii-Schiff (CBS) equation, and (2+1)-dimensional Bogoyavlenskii’s Breaking soliton equation are chosen to illustrate the effectiveness of the method. Mohammad Najafi, Maliheh Najafi, and Somayeh Arbabi Copyright © 2013 Mohammad Najafi et al. All rights reserved.