This paper presents a mixed grade magnet model for surface-inset machines considering the magnet thickness. In the polar coordinates, on the basis of the Laplace/quasi-Poisson equations and boundary conditions, the co...This paper presents a mixed grade magnet model for surface-inset machines considering the magnet thickness. In the polar coordinates, on the basis of the Laplace/quasi-Poisson equations and boundary conditions, the constructed matrix equations are solved and the air gap magnetic field in the machine is derived. Taking an 8-pole/12-slot surface-inset motor as an example, through the presented optimization process, the air gap field is optimized considering the magnet thickness, remanence and magnetization angle. In addition, the back-EMF and electromagnetic torque are analytically obtained. The optimized results show that the proposed mixed grade magnet model has larger electromagnetic torque and smaller torque ripple than the conventional one. Finally, the analytical predictions are evaluated by finite element analysis(FEA).展开更多
针对水泥稳定级配碎石混合料配合设计方法的不足,引入混合料目标级配的概念,提出填充料、嵌挤料、骨架料等配合比设计专用名词。以广东省普遍应用的水泥稳定级配碎石基层混合料级配范围为基础,采用统计归纳的方法,建立9条运营良好的高...针对水泥稳定级配碎石混合料配合设计方法的不足,引入混合料目标级配的概念,提出填充料、嵌挤料、骨架料等配合比设计专用名词。以广东省普遍应用的水泥稳定级配碎石基层混合料级配范围为基础,采用统计归纳的方法,建立9条运营良好的高速公路花岗岩类混合料填充料、嵌挤料、骨架料等相关通过率与7 d无侧限强度关系,并拟合各强度影响因素与无侧限强度之间的关系(校正决定系数Adj R 2=0.9178),构建了花岗岩类水泥稳定级配碎石配合比设计方法。新的配合比设计方法解决了水泥稳定级配碎石基层混合料级配设计目标不明确、经验要求高、设计工作量大等问题,且可在设计初期预估无侧限强度。展开更多
Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda（NaOH） dosage, the ratio of water to ore and the stirring rate on...Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda（NaOH） dosage, the ratio of water to ore and the stirring rate on tungsten recovery were studied. The results show that under the conditions that the ratio of water to ore is （0.8,） stirring rate is 500 r·min-1 and the heating time is 2.0 h at （160 ℃,） the recovery of tungsten reaches 98% for scheelite （w（WO3） is （65.04%）） and wolframite containing high proportion of calcium （w（WO3） is 65.58%, w（Ca） is （7.53%）,） when caustic soda dosage is 2.2 and 2.0 times of theoretical value, respectively; the recovery of tungsten can be more than 98%,98% and 96% respectively for low-grade scheelite-wolframite mixed concentrate with （55.78%,） 45.32% and 25.21% WO3, when caustic soda dosage is 2.6,3.2 and 5.5 times of theoretical value, respectively.展开更多
基金supported by the Anhui Provincial Natural Science Foundation under Grant 2008085ME179Anhui Province Key Laboratory of Renewable Energy Utilization and Energy Savingthe 111 Project under Grant BP0719039。
文摘This paper presents a mixed grade magnet model for surface-inset machines considering the magnet thickness. In the polar coordinates, on the basis of the Laplace/quasi-Poisson equations and boundary conditions, the constructed matrix equations are solved and the air gap magnetic field in the machine is derived. Taking an 8-pole/12-slot surface-inset motor as an example, through the presented optimization process, the air gap field is optimized considering the magnet thickness, remanence and magnetization angle. In addition, the back-EMF and electromagnetic torque are analytically obtained. The optimized results show that the proposed mixed grade magnet model has larger electromagnetic torque and smaller torque ripple than the conventional one. Finally, the analytical predictions are evaluated by finite element analysis(FEA).
文摘针对水泥稳定级配碎石混合料配合设计方法的不足,引入混合料目标级配的概念,提出填充料、嵌挤料、骨架料等配合比设计专用名词。以广东省普遍应用的水泥稳定级配碎石基层混合料级配范围为基础,采用统计归纳的方法,建立9条运营良好的高速公路花岗岩类混合料填充料、嵌挤料、骨架料等相关通过率与7 d无侧限强度关系,并拟合各强度影响因素与无侧限强度之间的关系(校正决定系数Adj R 2=0.9178),构建了花岗岩类水泥稳定级配碎石配合比设计方法。新的配合比设计方法解决了水泥稳定级配碎石基层混合料级配设计目标不明确、经验要求高、设计工作量大等问题,且可在设计初期预估无侧限强度。
文摘Scheelite and scheelite-wolframite mixed concentrates with different grades were decomposed by caustic soda digestion, and the effects of caustic soda（NaOH） dosage, the ratio of water to ore and the stirring rate on tungsten recovery were studied. The results show that under the conditions that the ratio of water to ore is （0.8,） stirring rate is 500 r·min-1 and the heating time is 2.0 h at （160 ℃,） the recovery of tungsten reaches 98% for scheelite （w（WO3） is （65.04%）） and wolframite containing high proportion of calcium （w（WO3） is 65.58%, w（Ca） is （7.53%）,） when caustic soda dosage is 2.2 and 2.0 times of theoretical value, respectively; the recovery of tungsten can be more than 98%,98% and 96% respectively for low-grade scheelite-wolframite mixed concentrate with （55.78%,） 45.32% and 25.21% WO3, when caustic soda dosage is 2.6,3.2 and 5.5 times of theoretical value, respectively.
