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this paper build up the brushless doubly fed machine (BDFM) finite element model of the coupled electromagnetic-thermal field, the electromagnetic joule heat calculated in electromagnetic environment will be loaded as the heat source to calculate in thermal field, the calculated results in thermal field will be the initial conditions to calculate the electromagnetic field, get the thermal field distribution when the motor is stable through cycle calculation at last. Calculation results show the effectiveness of this method.

The octenyl succinate starch is a stabilization-modified starch produced by esterification of native starch with octenyl succinic anhydride (OSA). When modified in this way the starch tends to improve its functional characteristics, can be used to tailor starch to specific food applications. Therefore, optimization of reaction conditions of octenyl succinate starch is critical for modification. The preparation of OSA starches from potato starch in an aqueous alkaline solution was investigated. The reaction conditions, including reaction temperature, OSA concentration, concentration of starch slurry, reaction time and pH, were studied and optimized, as they influence esterification. Under the optimization conditions, the degree of substitution (DS) could reach 0.01862. The products were confirmed by the presence of the carbonxylate signal around 1558 cm-1 in the fourier transform infrared (FT-IR) spectra. By scanning electron microscope (SEM), OSA starch granules were proved to transfer to some smaller anomalistic ellipses and had slight rough on their surfaces. X-ray diffraction showed that esterification occurred primarily in the amorphous regions and the crystalline pattern of starches did not change. The thermal characteristics of the OSA starch were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA revealed that the OSA starch were thermally more stable than the native starch. The OSA starch exhibited 50 % weight loss at 320°C, while the native starch underwent 50 % weight loss at 312°C. The DSC results showed that amorphous region increased after esterification.

Calcite is a common scale in water cooling systems treated and controlled with Organic phosphonates. The effect of three phosphonic acids (ethylene diamine tetra(methylene phosphonic acd), EDTMP; hexamethylene diamine tetra(methylene phosphonic acd), HDTMP; and diethylene triamine penta(methylene phosphonic acd), DTPMP) on the growth of the calcite has been investigated by pH curve method(pHCM). Experimental data obtains by pH value measurement of Ca(HCO3)2 supersaturated solution before and after precipitation. Besides, molecular dynamic simulations of the interaction of the phosphonic acids with the calcite(104) indicate the inhibitor effectiveness: EDTMP< DTPMP< HDTMP according to the difference in the carbon chain between nitrogen atoms. This is in agreement with the pHCM measurements.