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Amyl ferulate was synthesized by direct esterification with using sodium bisulfate supported by silica as a catalyst, ferulic acid and n-pentanol as raw materials. The influences of some factors on the synthetic process were studied. The optimal reaction conditions based upon 0.2 mol of ferulic acid were chosen that the molar ratio of n-pentanol and ferulic acid was 2 : 1, the mass ratio of catalyst to reactants was 6%, refluxing reaction time was 3 hours. The yield of the product reached 97% under the above conditions. The structure of the product was characterized by IR, 1H NMR and MS spectrum. The catalyst could be recycled and used for many times.

Data security and privacy protection of cloud computing as a new IT application mode are the most valued and concerned issues of the cloud user,and thus of utmost significance to the security of cloud computing. This paper describes and analyzes in detail the risks of data security and privacy showup brought by cloud computing,discusses the protective approaches of data security and privacy in cloud computing environment. Furthermore, this paper based on the newly developed fully homomorphism encryption then proposed a data security scheme which can operate encrypted data directly on cloud server without decrypt while all communication between client and server is encrypted, it can assure data security at the mean time assure the operate efficiency.

Cyclohexyl ferulate was prepared by direct sterification of ferulic acid and cyclohexanol as raw materials with sodium bisulfate supported by silica as a catalyst. The influences of some factors on the synthesis process were studied. The optimal reaction conditions based upon 0. 2 mol of ferulic acid were chosen that the molar ratio of cyclohexanol and ferulic acid was 10 : 1, the mass ratio of catalyst to reactants was 5%, refluing reaction time was 3.5 hours, et a1. The yield of the product reached 80%. The structure of the product was characterized by IR, 1H NMR and MS spectrum. The catalyst could be recycled and used for many times, which is friendly to the environment.

The Henkel plot and the Δm plot of a longitudinal barium ferrite hard disk and γ-Fe2O3 flexible disk were simulated by the improved Preisach-DOK model.The study results show that the barium ferrite exhibit large positive interactions, as shown by large positive in the Δm plot, and tend to resist demagnetization, leading the oriented barium ferrite possess the unusual remanence characteristic.

To design a truss structure of deployable truss antenna with 7 modules and ensure that the truss structure can be deployed successfully in space environment, kinematics equation of single module with homogeneous coordinate transformation method is built based on the structure and deployment principle of truss structure. By using dynamics software ADAMS, simulation analysis on the deployment is carried out and the driving force of single module is obtained in the ground condition. On this basis, driving spring is designed, and all the important design parameters are obtained. The analytical results show that the driving spring can meet the requirement of deployment in the ground condition. So it can be deployed in orbit (0G). This method can be taken as the theoretical basis for the design and deployment experiment of truss structure.

The water resources is a complex coupling system,combined with the human social development and living environment. Water resources optimal allocation plays an important role in supporting the whole sustainable development of national economy in Weinan city as the solution about the shortage of urban water resources .In this paper, we take the urban water supply and the water resources system in Weinan city as the research object, through the analysis of the actual data, analyzing the elements and relationships between systems of urban water supply in Weinan city and the characteristics of the water resources project, adopting optimization theory of dynamic programming principle to build the Weinan city water resources optimization allocation model, and puts forward the method of benefit function to obtain the strategy plan for optimal allocation of water resources in the city.

In the research of flow and heat transfer of the diesel engine cooling system, the boundary condition determination was often a difficult problem. The paper calculated the flow velocity and convective heat transfer coefficient respectively for a six-cylinder diesel engine under different boundary conditions which including the water jacket wall as adiabatic condition, average temperature condition, and the boundary conditions from the solid-fluid coupling calculating. And the calculated values of the jacket wall temperatures were compared with that of test. The results showed that the simulation with solid-fluid coupling boundary conditions had better precision. Based on the research, an improved structure design was conducted for the six-cylinder diesel engine, the results of simulation showed that the average flow speed at the internal surface of water jacket could reach up to 0.5m/s, the flow symmetry in each jacket got improved, and the convective heat transfer coefficient could reach more than 2000 W/m2·K. The improved cooling system can meet the design requirements.

The microstructure and tensile properties at room temperature of as-extruded Mg94.5Zn4Y1Er0.5 alloy sheet were studied. The results show that the alloy is mainly composed of equiaxial-liked α-(Mg) grains and W phase containing lots of rare earth elements (F.C.C. structure, a=0.707nm). The elongation and tensile strength of the alloy sheet in hot extruded and transverse direction are 25.5 %, 29.9 % and 247 MPa, 240 MPa, respectively. The above results manifest that the W phase stimulate the DRX during hot extrusion, reduce the preference of basal texture of magnesium alloy, markedly improve the plastically shaping capability at room temperature.