Advanced Materials Research Vols. 433-440

Abstract: In this article, based on a combined chemical mechanism with detailed ethanol oxidization and NO production mechanisms, a single cylinder ethanol HCCI engine model was established using the software CHEMKIN. Comparing with experimental data, this model can well predict cylinder pressure and NO emission. By changing mole fraction of hydrogen peroxide in initial ethanol mixture at different conditions, the effect of hydrogen peroxide additive on ethanol HCCI engine performance was investigated. The results show that hydrogen peroxide can effectively improve cylinder pressure and advance heat release progress, without notably increasing NO production.

Abstract: TiB2-TiC complex phases coating deposited onto the surface of electrodes by electro-spark deposition (ESD) in order to prolong the life of single phase coated electrode (TiB2 or TiC) during resistance welding of galvanized steels. The microstructures and TiB2-TiC complex phases coatings were characterized by SEM and XRD. The results indicate that life of TiB2-TiC complex phases coated electrode is prolonged significantly than life of single-phase coated electrode （TiB2 or TiC ）, failure mechanism of TiB2-TiC complex phases coated electrode is mainly wear to cause diameter increase on electrode tip, which results in lower current density during welding process, and then nugget size cannot satisfy the requirement of resistance spot welding. The failure mechanism of TiB2-TiC complex phases coated electrode is obviously different from uncoated electrode, the failure mechanism of uncoated electrode is wear and alloying between electrode tip surface and molten Zn on galvanized steel weld surface.

Abstract: Base on the representation of the spatially-variant (SV) binary mathematical morphology operators, we develop a representation of the mathematical morphology on Boolean lattice through the automorphisms group and sup-generating family. Moreover, the spatially-variant (SV) Euclide mathematical morphology operators in the Boolean lattice case are unified.

Abstract: Water quality prediction has a great significance to evalute the quality development trend of water and make the planning of water processing. In the study, a novel hybrid method of grey model and support vector regression is proposed to improve the prediction accuracy of sypport vector regression. COD is the important composition in the polluting water. Thus, COD is used as evaluation index of polluting water in the paper. The quality prediction values of input and output water of BP nerual network and the hybrid method of grey model and support vector regression are computated respectively. It is indicated that the water quality prediction by using the hybrid method of grey model and support vector regression is superior to BP nerual network.

Abstract: A geomagnetic storm is a global disturbance in Earth’s magnetic field usually occurred due to abnormal conditions in the interplanetary magnetic field (IMF) and solar wind plasma emissions caused by various solar phenomenon. A study of 220 geomagnetic storms associated with disturbance storm time (Dst) decreases of more than -50 nT to -300 nT, observed during 1996-2007, the span of solar cycle 23. We have analyzed and studied them statistically. We find yearly occurrences of geomagnetic storm are strongly correlated with 11-year sunspot cycle, but no significant correlation between the maximum and minimum phase of solar cycle-23 have been found. It is also found that solar cycle-23 is remarkable for occurrence of Intense geomagnetic storm during its declining phase. The detailed results are discussed in this paper.

Abstract: In the present work we reanalyzed the fields of magnetic materials on the instance of absence of magnetic monopoles. First we reanalyzed the field of a current carrying conductor which determines its true face as an electric field which is parallel to the wire having zero divergence and non-zero curl. The force exerted on a charged particle by this field has unique direction and does not depend on the direction of the motion of the particle. The non-zero curl of the field causes the force to be asymmetric in nature because of which a charged particle, placed in it, never moves along a straight path and follows a curved path. The study explores a basic difference between the real force and the supposed magnetic force in the fields of magnetic materials suggesting that there is no magnetic field which we have been considering. The real force in fields of all magnetic materials is electric and exerts in terms of field-field interaction. Experimental evidences for the same are reported. The interaction between poles of bar magnets, the induction of emf and Lenz’s law are explained on the basis of curled electric fields.

Abstract: It is important to assess the effects of missile and rocket launching on the launcher health and surrounding structures. Since an accurate measurement of the launch noise environment is time consuming and extremely cost prohibitive. And nowadays, there is no reliable theoretical method. in order to calculate the sound field generated by high-speed high temperature jets. Therefore, engineering approaches are widely used in practice. In this paper considers semi-empirical jet noise models and their development and application. Listing of some the open questions and future directions concerning supersonic jet noise predictions using semi-empirical methods concludes the survey.

Abstract: Stereo SAR geolocation model is an important geolocation model for spaceborne synthetic aperture radar (SAR). Stereo SAR geolocation model need a stereo radar image pair whose generation have much influence on the geolocation accuracy. In this paper,a novel generation method of spaceborne SAR stereo image pair for geolocation is presented which could avoid the geolocation error caused by intersection angle error.Through computer simulation,the results verify the validity of the generation method.

Abstract: In this paper, we propose three entire coloring schemes for regular planar meshes — square meshes, hexagonal meshes and honeycomb meshes, respectively. Based on these schemes, we propose three efficient entire coloring algorithms for these three planar meshes and prove that the entire chromatic number of square meshes is 7 (maximum degree plus 3), the entire chromatic number of hexagonal meshes is 9 (maximum degree plus 2), and the entire chromatic number of honeycomb meshes is 7 (maximum degree plus 4).

Abstract: A new technology of initiative protection for lightning stroke based on electric field cancellation theory is presented in this paper. The real time lightning detection system and the active protection equipment are adopted. By using this new method, the protection technology of direct lightning stroke can be changed from little current triggering to weakening the electric field near the weapon system, and the down leader of charged thundercloud can be repulsed by the artificial opposed field. So the lightning discharge condition in this protection region can be destructed, and the lightning hazard to the protected equipment is eliminated radically. It effectively reduces the electromagnetic radiation, ground potential reaction and step voltage caused by the high current along conducting wire in the conventional lightning rod protection technology.