Hard red spring wheat in North America must be high in protein in order to avoid costly discounts when marketed. Many newer cultivars have higher yield potential but produce relatively lower grain protein levels. A po...Hard red spring wheat in North America must be high in protein in order to avoid costly discounts when marketed. Many newer cultivars have higher yield potential but produce relatively lower grain protein levels. A post-anthesis foliar application of urea-ammonium nitrate mixed with equal part water at 33 kg·ha<sup>-1</sup> nitrogen (N) can increase grain protein levels by up to one percent. This increase can be profitable when market premiums/discounts for protein are moderate to high. Nitrogen applied post-anthesis consistently increased grain protein content more than the application of the same rate of N to the soil prior to planting. Milling and baking analysis reveals augmenting the protein in this way does not diminish its functionality.展开更多
In this paper, two different designs, with dummy slots and bread-loaf magnets techniques, are presented to reduce the electromagnetic vibration in integral-slot surface-mounted permanent-magnet(SPM) machines. Firstly,...In this paper, two different designs, with dummy slots and bread-loaf magnets techniques, are presented to reduce the electromagnetic vibration in integral-slot surface-mounted permanent-magnet(SPM) machines. Firstly, the stator slotting effect on the magnetic field modulation and radial force modulation is investigated. It reveals the amplitude of the modulated magnetic field and modulated radial force is greatly affected by the slot opening effect, while the spatial order is closely associated with the slot numbers. Subsequently, the dummy slots and bread-loaf magnets design are developed for a 36-slot/12-pole integral-slot SPM machine to reduce the electromagnetic vibration. Finally, two SPM machines, with conventional and bread-loaf magnets,are manufactured. Experimental tests are carried out to validate the theoretical analyses.展开更多
The influence of bread-loaf shaped magnet poles under parallel magnetization on the cogging torque of surface-mounted permanent magnet(SPM)motors is studied.For the SPM motors having magnetic poles with eccentricity a...The influence of bread-loaf shaped magnet poles under parallel magnetization on the cogging torque of surface-mounted permanent magnet(SPM)motors is studied.For the SPM motors having magnetic poles with eccentricity and sine harmonic compensation,the electromagnetic performances of integer and fractional slot motors are compared.It is found that the cogging torque and torque ripple of the integer and fractional slot motors can be reduced with the same eccentric magnet pole.The cogging torque and torque ripple of a fractional slot motor can be decreased by sine harmonic compensation,however,the same sine harmonic compensation has a small influence in integer slot motors.By varying the magnetic poles,the contribution of the field harmonics(k=(2n+1)p),which are a direct result of magnet magnetization,to the cogging torque also changes.The electromagnetic performance of a 3 kW prototype is tested,and it is found that the experimental results validate the theoretical investigation.展开更多
文摘Hard red spring wheat in North America must be high in protein in order to avoid costly discounts when marketed. Many newer cultivars have higher yield potential but produce relatively lower grain protein levels. A post-anthesis foliar application of urea-ammonium nitrate mixed with equal part water at 33 kg·ha<sup>-1</sup> nitrogen (N) can increase grain protein levels by up to one percent. This increase can be profitable when market premiums/discounts for protein are moderate to high. Nitrogen applied post-anthesis consistently increased grain protein content more than the application of the same rate of N to the soil prior to planting. Milling and baking analysis reveals augmenting the protein in this way does not diminish its functionality.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51991383 and 52025073)。
文摘In this paper, two different designs, with dummy slots and bread-loaf magnets techniques, are presented to reduce the electromagnetic vibration in integral-slot surface-mounted permanent-magnet(SPM) machines. Firstly, the stator slotting effect on the magnetic field modulation and radial force modulation is investigated. It reveals the amplitude of the modulated magnetic field and modulated radial force is greatly affected by the slot opening effect, while the spatial order is closely associated with the slot numbers. Subsequently, the dummy slots and bread-loaf magnets design are developed for a 36-slot/12-pole integral-slot SPM machine to reduce the electromagnetic vibration. Finally, two SPM machines, with conventional and bread-loaf magnets,are manufactured. Experimental tests are carried out to validate the theoretical analyses.
基金Supported by the Key Research and Development Program of Jiangsu Province(BE2018107).
文摘The influence of bread-loaf shaped magnet poles under parallel magnetization on the cogging torque of surface-mounted permanent magnet(SPM)motors is studied.For the SPM motors having magnetic poles with eccentricity and sine harmonic compensation,the electromagnetic performances of integer and fractional slot motors are compared.It is found that the cogging torque and torque ripple of the integer and fractional slot motors can be reduced with the same eccentric magnet pole.The cogging torque and torque ripple of a fractional slot motor can be decreased by sine harmonic compensation,however,the same sine harmonic compensation has a small influence in integer slot motors.By varying the magnetic poles,the contribution of the field harmonics(k=(2n+1)p),which are a direct result of magnet magnetization,to the cogging torque also changes.The electromagnetic performance of a 3 kW prototype is tested,and it is found that the experimental results validate the theoretical investigation.
