We investigate the beam focusing technology of shear-vertical(SV) waves for a contact-type linear phased array to overcome the shortcomings of conventional wedge transducer arrays. The numerical simulation reveals the...We investigate the beam focusing technology of shear-vertical(SV) waves for a contact-type linear phased array to overcome the shortcomings of conventional wedge transducer arrays. The numerical simulation reveals the transient excitation and propagation characteristics of SV waves. It is found that the element size plays an important role in determining the transient radiation directivity of SV waves. The transient beam focusing characteristics of SV waves for various array parameters are deeply studied. It is particularly interesting to see that smaller element width will provide the focused beam of SV waves with higher quality, while larger element width may result in erratic fluctuation of focusing energy around the focal point. There exists a specific range of inter-element spacing for optimum focusing performance. Moreover, good beam focusing performance of SV waves can be achieved only at high steering angles.展开更多
ln this research, the whole contact-type large-scale sow house with fer-mentation bed was designed. The planning area of the entire piggery was 5 700 m2 with workplace and green belts. The sow house was 93 m long and ...ln this research, the whole contact-type large-scale sow house with fer-mentation bed was designed. The planning area of the entire piggery was 5 700 m2 with workplace and green belts. The sow house was 93 m long and 33 m wide, a total of 3 069 m2, including office area of 60 m2 and aisle area of 107 m2. The fer-mentation bed had an area of 2 902 m2 with length of 88.7 m and width of 27.7 m. lts area accounted for 95% of the total area of sow house. The fermentation mattress had a depth of 80 cm, and had a volume of 2 321 m3, equivalent to 733 t of coconut chaff and rice chaff. On a large fermentation bed, the areas for boars, replacement gilts, pregnant sows, obstetric tables, nursery pigs, etc. were designed. The large-scale sow house with fermentation bed was equipped with the automatic feeding system, automatic sprinkler system, automatic positioning column for preg-nant sows, sows＇ obstetric table system, fanning wet curtain cooling system, video monitoring system, environmental monitoring （light, temperature, water, humidity, CO2, NH3） and automatic control system. Every farming area was equipped with feeding trough and water trough. The water though was fixed with overflow pipe for removing the extra water. The house could hold 500-head sows. Each sow occu-pied 4.9 m2 of the fermentation bed in average. The designed sow house had a maximum annual output of 10 000 piglets.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774377 and 11574343)。
文摘We investigate the beam focusing technology of shear-vertical(SV) waves for a contact-type linear phased array to overcome the shortcomings of conventional wedge transducer arrays. The numerical simulation reveals the transient excitation and propagation characteristics of SV waves. It is found that the element size plays an important role in determining the transient radiation directivity of SV waves. The transient beam focusing characteristics of SV waves for various array parameters are deeply studied. It is particularly interesting to see that smaller element width will provide the focused beam of SV waves with higher quality, while larger element width may result in erratic fluctuation of focusing energy around the focal point. There exists a specific range of inter-element spacing for optimum focusing performance. Moreover, good beam focusing performance of SV waves can be achieved only at high steering angles.
基金Supported by Chinese Ministry of Science and Technology(2012DFA31120)Natural Science Foundation of China(NSFC)(31370059)+2 种基金948 Project of Chinese Ministry of Agriculture(2011-G25)973 Program Earlier Research Project(2011CB111607)Project of Agriculture Science and Technology Achievement Transformation(2010GB2C400220)
文摘ln this research, the whole contact-type large-scale sow house with fer-mentation bed was designed. The planning area of the entire piggery was 5 700 m2 with workplace and green belts. The sow house was 93 m long and 33 m wide, a total of 3 069 m2, including office area of 60 m2 and aisle area of 107 m2. The fer-mentation bed had an area of 2 902 m2 with length of 88.7 m and width of 27.7 m. lts area accounted for 95% of the total area of sow house. The fermentation mattress had a depth of 80 cm, and had a volume of 2 321 m3, equivalent to 733 t of coconut chaff and rice chaff. On a large fermentation bed, the areas for boars, replacement gilts, pregnant sows, obstetric tables, nursery pigs, etc. were designed. The large-scale sow house with fermentation bed was equipped with the automatic feeding system, automatic sprinkler system, automatic positioning column for preg-nant sows, sows＇ obstetric table system, fanning wet curtain cooling system, video monitoring system, environmental monitoring （light, temperature, water, humidity, CO2, NH3） and automatic control system. Every farming area was equipped with feeding trough and water trough. The water though was fixed with overflow pipe for removing the extra water. The house could hold 500-head sows. Each sow occu-pied 4.9 m2 of the fermentation bed in average. The designed sow house had a maximum annual output of 10 000 piglets.
