The influence of solute atoms on point-defect properties and defect generation by radiation damage in alloys is known to be important, and hence it is desirable to understand their effect on the basic mecha- nisms involved. Most computer modeling of these phenomena has only considered pure metals, but as part of a project to investigate displacement cascades in alloys, we have simulated dilute solutions of gold (Au) in copper (Cu), treating this as a "model" for a heavy, oversized solute alloy system. In the present paper, modified many-body interatomic potentials for the Cu-Au system are described that are suitable for modeling high-energy atomic collisions. The properties of point defects in pure copper and the dilute alloy, including solute-defect binding energies, are presented. The oversized solute has a larger binding energy with an interstitial atom than with a vacancy. The displacement threshold energy, Ea, of a Cu atom and a Au atom in the copper matrix has been investigated as a function of primary recoil direction, and the difference between the two species is found to be substantial. Furthermore, the pres- ence of a Au solute has a significant effect on the formation of Frenkel pairs by the replacement- collision-sequence mechanism. These results are discussed in terms of the mass and size difference of Cu and Au atoms.

In this paper, an improved Lsb (Least Significant Bits) information hiding algorithm is proposed according to human visual theory and implemented in the temporal-spatial domain by using C#, and based on this, a system is developed for hiding and extraction of multimedia files, Compared with the traditional LSB method implemented by Matlab, the improved one has obvious advanlages in the environmental confguration requirements, the time-consuming in running and ease of use, To be specific, the system realized on, net platform takes less running time and resouces, has better extensibility and greatere ease-to-use, and other distinct features Besides, the system developed for hiding and extracting multimedia files based on the method has a wide range of adaptivity and good applicability.

Research into displacement cascade processes in alloy systems has received little attention, yet is potentially of interest because issuessuch as the effect of solutes on the displacement threshold and the defectdistribution and movement in cascades are important. As part of a widerstudy, we have initially considered the minor substitutional solute Au in a Cu matrix, and have used molecular dynamics to investigate the properties of point defects, the threshold displacement energy Ed, and temporal and spatial distribution of defects in low-energy (≤500 eV) displacement cascades. The results show that the influence of the solute on the properties of defects is important and that Edis dramatically different from its form in pure copper. In comparison with pure copper,the recoil of the Au solute gives rise to a higher peak at longer timesin the number of displaced atoms in the generation of a displacement cascade. The influence of this on defect density in the cascade and thefinal number and arrangement of defects has been investigated.

In this paper, we consider a pariicular model of electron-beam-inducedpair excitation. This model takes account of thickness dependence and istherefore considerably more realistic than the constant generation rate assumedwe in a previous paper. The surface recombination velocity (SRVo) n the uppersurface can be varied independently of that on the lower surface. An exactanalytical expression for the Green function (GF) has been found. Funher, generalexpressions for the minoriiy carrier concentration profile (MCCPa), nd hence forthe cathodoluminescence intensity (cu) are constructed merely by convolving theGF with the pair-generation function which is allowed to assume arbitrary form.Here a 'correlation function' form of the pair excitation density is considered whichnon-trivially makes the entire problem be of completely analytical formulation. Theinfluence of various physical parameters, especially the SRV, the diffusion length(oL), and the incident vonage on the MCCP and cu, are discussed in more detailtheoretically and numerically. Explicit analytical forms of the GF, MCCP, and cuare given for various surface-recombination conditions as well as expressionsfor junction current (JC) in the charge-collecting modes. An example is givenof a model prediction in agreement with experimental results which cannot beobtained by previously existing models. It is found that the present formalism canalso be used to tackle the problems of dislocation-or defect-imaging contrastand resolution in thin film materials within some approximation scheme andthat many past models can be reproduced from the present model as specialcases. It is anticipated that the generality of the model which we propose willbe of considerable interest in seeking an understanding of experimental resuns.Quantitative calculations reveal many interesting and even unusual featurescontained in the new model

By a thorough analysis of the contents and scope of the publiclogistics information, a role-based multilevel solution of information sharing isproposed. And by use of metadata theory, the unified description andclassification of the information are done with an aim to achieve heterogeneousdata sharing and exchanging. Based on this, a service-oriented-architecture(SOA)-based system framework is put forward in order to integrate and reuseexisting systems, data and service resources. By introducing web service andbusiness process execution language (BPEL), etc. into the solution, servicesreuse and businesses automatisation are achieved. In this way, the degree ofinformatisation of supply chains management can be deepened, the interactionsbetween governmental departments and enterprises can be enhanced and theprocess of customs e-governing can be accelerated. Finally, an application ofthe solution to a logistics customs clearance information sharing platform isalso given to show its applicability.