The (G'/G, 1/G)-expansion method and its application to travelling wave solutions of the Zakharov equations

The （G＇/G, 1/G）-expansion method for finding exact travelling wave solutions of nonlinear evolution equations, which can be thought of as an extension of the （G＇/G）-expansion method proposed recently, is presented. By using this method abundant travelling wave so- lutions with arbitrary parameters of the Zakharov equations are successfully obtained. When the parameters are replaced by special values, the well-known solitary wave solutions of the equations are rediscovered from the travelling waves.

Microstructure and corrosion mechanism of as-cast Mg-Zn-Mn-Ca in Hank's solution

An Mg-Zn-Mn-Ca alloy with high Zn content was fabricated by vacuum melting. The as-cast microstructure was investigated using XRD, SEM and EDS. It was shown that the alloy was composed of α-Mg, strip-like Ca2Mg6Zn3 and a few Mn- containing phases. Most of the Ca2Mg6Zn3 phase was distributed at grain boundaries while Mn-containing particles were deposited within grains. The as-cast samples were immersed in a Hank＇s balanced salt solution （HBSS） up to 24 h. The corroded surface morphology and cross-section microstructure were analyzed after different time of immersion so as to understand the corrosion behavior of the alloy. During immersion in the HBSS, the alloy corroded homogeneously at the very beginning and then localized corrosion occurred. The secondary phases protruded on the surface due to the dissolution of α-Mg, suggesting micro- galvanic corrosion occurred with secondary phases acting as the cathode and ct-Mg as the anode. Micro-cracks were formed at the interfaces between Ca2Mg6Zn3 and α-Mg, indicating an undermining tendency of the secondary phases.

Co-doping method used to improve the charge transport balance in solution processed OLEDs

In this paper, co-doping method is used to improve the current efficiency of solution-processed organic light-emitting diodes(OLEDs). By changing the ratio of two thermally activated delayed fluorescent(TADF) emitters, we studied the performance of device and its mechanism. A solution processed OLED with a structure of indium tin oxide(ITO, 150 nm)/PEDOT:PSS(30 nm)/CBP:4 Cz IPN-x%:4 Cz PN-y%(30 nm)/TPBi(40 nm)/Li F(1 nm)/Al(100 nm) was fabricated. The current efficiencies of 26.6 cd/A and 26.4 cd/A were achieved by the devices with dopant ratio of 6% 4 Cz IPN:2% 4 Cz PN and 2% 4 Cz IPN:6% 4 Cz PN in emitting material layer(EML), respectively. By investigating the tendency of current density change in devices with different doping ratio, we suggested that the enhancement of the current efficiency should be due to the charge transport balance improvement induced by assist dopant in EML.

TRAVELING WAVE SOLUTIONS AND THEIR STABILITY OF NONLINEAR SCHRDINGER EQUATION WITH WEAK DISSIPATION

In this paper,several new constant-amplitude and variable-amplitude wave solutions（namely,traveling wave solutions） of a generalized nonlinear Schrdinger equation are investigated by using the extended homogeneous balance method,where the balance method is applied to solve the Riccati equation and the reduced nonlinear ordinary differential equation,respectively.In addition,stability analysis of those solutions are also conducted by regular phase plane technique.