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A novel approach to assemble the (12S)-12-Hydroxymonocerin’s core skeleton was developed in 29% overall yield, in which a three component Linchpin coupling, stereocontrolled reduction and an intramolecular Friedel-Crafts/Marson cyclization were utilized as key steps.

Poly (ethylene terephthalate)/poly (trimethylene terephthalate) (PET/PTT) blends were prepared and their melting and crystallization properties were investigated by differential scanning calorimetry (DSC). The glass transition temperatures suggest apparently that PET and PTT have good miscibility at amorphous state. The blends with more PET content less likely undergo a melting/recrystallization process during DSC heating scan. In the blends, PET component with higher supercooling degree will crystallize first, and then the crystallites of PET will be the nucleating agents for PTT, which greatly improves the crystallization rate of PTT.

Concerning the security issues in the running elevator and the fact that elevator monitoring is an effective means to ensure the safe running of the elevator, and the special equipment, users, manufacturers, and government supervision departments will need to master the operating conditions of the elevator. Therefore, combining with the main components, embedded microprocessor, RF communications modules, sensors and GPRS designed the remote elevator monitoring terminal, and complete real-time acquisition of the state data of the running elevator via GPRS communication module to send data to a remote network server. Monitoring terminal cooperates with the web server, database, and host computer software, then realize the remote monitoring and control of the elevator group. Practice has proved the feasibility, effectiveness and reliability of the design of the monitoring terminal.

After the fuel changed fromgasoline to kerosene of internal combustion engine, the engine cold startperformance is poor due to the poor spray evaporation of kerosene fuel. In thepaper, the ignition factors are to be analyzed based on the gas dischargetheory. Improving the spark plug discharge and increasing the ignition energyare used to improve the cold start performance of engine. The experimentalresults show that the method can improve the cold start performance of engine,which provides the basis for the engine burning kerosene fuel

To determine the optimal thresholds in image segmentation, a new multilevel thresholding method based on improved particle swarm optimization (IPSO) is proposed in this paper. Firstly, use the conception of independent peaks to divide the histogram to several regions, secondly, the optimization object function using maximum between-class variance (MV) method can be gotten in each area, by the non-uniform mutation and Geese-LDW PSO optimization of the object function, the optimal thresholds can be gotten, and the image can be segmented with the thresholds. Compared with the basic MV algorithm and genetic algorithm (GA) modified MV, the experimental results show that the new method not only realizes the image segmentation well, but also improves the speed.

The aim of this study is to explore the effects of quenching and milling processing on setting property of calcium phosphate cement (CPC). For this purpose, non-quenched α-tricalcium phosphate (α-TCP) and quenched α-TCP were synthesized and their corresponding cement systems were prepared. The particle size of α-TCP powder was introduced as a variable. Then, setting properties of these CPC systems were estimated. By a comparison between non-quenched CPC and the quenched one, it is found that milling processing mainly influences the initial setting stage by decreasing reactant particle size whereas the quenching treatment affects the final setting stage by changing α-TCP content, which supports that CPC setting initially depends on the surface area of reactants and subsequently on the diffusion through the hydrated layer formed around the reactants.