Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high a...Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high as 196 mg of S per gram of adsorbent was demonstrated. The influence of loading amount of Cu （II） and calcination temperature on adsorptive desulfurization was investigated. Test results revealed that the optimum loading amount of Cu （II） was 15%, and the calcination temperature was 150 ℃. The pyridine-FTIR spectroscopy showed that a certain amount of Lewis acid could contribute to the increase of adsorption capacity. Spectral shifts of the v（C-S） and v（Cu-S） vibrations were detected from the Raman spectra of the Cu （II） complex which was a reaction product of CuBr2 with DMS. According to the hybrid orbital theory and the complex adsorption reaction, the desulfurization of PM and DMS over the CuBr2 modified bentonite is ascribed to the formation of S-M （σ） bonds.展开更多
Pollution of heavy metals Cu,Pb and Hg is assessed using geo-accumulation index in this paper. The result shows that the bottom sediments of surface water in Xuzhou is polluted by these heavy metals to deferent degree...Pollution of heavy metals Cu,Pb and Hg is assessed using geo-accumulation index in this paper. The result shows that the bottom sediments of surface water in Xuzhou is polluted by these heavy metals to deferent degrees, of which the Jinma River is the most serious, and then the Kuihe River, the abandoned Yellow River, and the Jinghang Canal. The Yunlong Lake has also been polluted by Hg. The three kinds of heavy metals in the order of concentration is Hg>Cu>Pb. The pollution degree and the type of element is closely related with industrial structure in Xuzhou.展开更多
Aiming at the problem of large AC copper loss caused by skin effects and proximity effects,and low efficiency at high speed of the hairpin-winding permanent magnet synchronous motor(PMSM)for electric vehicles(EVs),thi...Aiming at the problem of large AC copper loss caused by skin effects and proximity effects,and low efficiency at high speed of the hairpin-winding permanent magnet synchronous motor(PMSM)for electric vehicles(EVs),this paper firstly established the electromagnetic analytical model of the hairpin winding to calculate AC resistance.And the finite element model(FEM)of the hairpin-winding driving motor is established to calculate the AC characteristic of the hairpin winding at different speeds and temperatures.Then,combining modified particle swarm optimization(MPSO)and FEM,a 60 k W hairpin-winding PMSM is optimized under driving cycle conditions,and the electromagnetic performance and heat dissipation performance are compared with that of the traditional strand-winding motor.Finally,a prototype is made and an experimental platform is built to test the efficiency Map and temperature rise of the hairpin-winding motor over the whole speed range and verify the accuracy of the proposed optimization design method.The results show that the hairpin-winding PMSM not only has higher slot filling rate,high?efficiency range and power density,but also has better heat dissipation performance,which is suitable for application in the field of electric vehicles.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21276086)
文摘Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high as 196 mg of S per gram of adsorbent was demonstrated. The influence of loading amount of Cu （II） and calcination temperature on adsorptive desulfurization was investigated. Test results revealed that the optimum loading amount of Cu （II） was 15%, and the calcination temperature was 150 ℃. The pyridine-FTIR spectroscopy showed that a certain amount of Lewis acid could contribute to the increase of adsorption capacity. Spectral shifts of the v（C-S） and v（Cu-S） vibrations were detected from the Raman spectra of the Cu （II） complex which was a reaction product of CuBr2 with DMS. According to the hybrid orbital theory and the complex adsorption reaction, the desulfurization of PM and DMS over the CuBr2 modified bentonite is ascribed to the formation of S-M （σ） bonds.
文摘Pollution of heavy metals Cu,Pb and Hg is assessed using geo-accumulation index in this paper. The result shows that the bottom sediments of surface water in Xuzhou is polluted by these heavy metals to deferent degrees, of which the Jinma River is the most serious, and then the Kuihe River, the abandoned Yellow River, and the Jinghang Canal. The Yunlong Lake has also been polluted by Hg. The three kinds of heavy metals in the order of concentration is Hg>Cu>Pb. The pollution degree and the type of element is closely related with industrial structure in Xuzhou.
基金supported by the Fundamental Research Funds for the Central Universities(No.2019YJS181)。
文摘Aiming at the problem of large AC copper loss caused by skin effects and proximity effects,and low efficiency at high speed of the hairpin-winding permanent magnet synchronous motor(PMSM)for electric vehicles(EVs),this paper firstly established the electromagnetic analytical model of the hairpin winding to calculate AC resistance.And the finite element model(FEM)of the hairpin-winding driving motor is established to calculate the AC characteristic of the hairpin winding at different speeds and temperatures.Then,combining modified particle swarm optimization(MPSO)and FEM,a 60 k W hairpin-winding PMSM is optimized under driving cycle conditions,and the electromagnetic performance and heat dissipation performance are compared with that of the traditional strand-winding motor.Finally,a prototype is made and an experimental platform is built to test the efficiency Map and temperature rise of the hairpin-winding motor over the whole speed range and verify the accuracy of the proposed optimization design method.The results show that the hairpin-winding PMSM not only has higher slot filling rate,high?efficiency range and power density,but also has better heat dissipation performance,which is suitable for application in the field of electric vehicles.
