Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for smallholders.The current research work provides additional options for small plots,as t...Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for smallholders.The current research work provides additional options for small plots,as the only income source for low-income farmers in poorer countries,which produce a considerable portion of the agricultural products in some regions of the world.In this research,two novel layouts of a semipermanent sprinkler irrigation system,namely,clock hand(CH)and corner pivot(CP)lateral designs,were designed for a lighter irrigation system to lower the cost requirement.The new techniques were based on a quadrant/full circle movement pattern of manually pivoting laterals,with no/shorter main pipe requirements,which causes a higher system efficiency.These retrofitted layouts were examined in different farms with areas of 0.20 hm^(2),0.81 hm^(2),1.62 hm^(2),and 3.24 hm^(2) in Guangxi,China.This study introduced,analyzed,and compared the layouts with the widespread traditional split lateral method on technical planning,components,implementation,operation details,size optimization,performance evaluation,and economic advantages.In comparison with the traditional system,CH and CP were found to be more user-friendly and cost-effective but slightly complicated in design with higher required manual work.The results revealed a distribution uniformity(LQDU)of 81.0%to 84.0%via the catch can method,lower capital costs(35.0%-45.0%),and lower annual expenses(6.5%-9.8%)for CP and CH,respectively,compared to the split lateral method.The 0.81 hm^(2) and 1.62 hm^(2) farms were found to be the optimum farm sizes for implementation of the new methods for a 25-year project time horizon.The outcomes of this experimental work can encourage small farm owners with limited capital to apply pressurized systems for efficient irrigation and water resource sustainability.展开更多
目的观察尿激酶两种不同的应用方法针对血液透析用半永久性双腔导管尖部血栓及纤维蛋白鞘的预防及治疗方法的效果观察。方法选择河北医科大学第三医院血液净化中心2010年1月~12月行半永久性双腔导管置管血液透析患者20例,其中男性11例,...目的观察尿激酶两种不同的应用方法针对血液透析用半永久性双腔导管尖部血栓及纤维蛋白鞘的预防及治疗方法的效果观察。方法选择河北医科大学第三医院血液净化中心2010年1月~12月行半永久性双腔导管置管血液透析患者20例,其中男性11例,女性9例;年龄45～82岁,平均年龄56岁。随机分为2组。共行血液透析2210例次。观察组采用100 kU尿激酶加入100 mL 0.9%NaCl溶液缓慢滴注,对照组采用尿激酶肝素混合液封管,比较透析前导管抽吸不畅事件及透析过程中护理干预情况。结果观察组透析前导管抽吸不畅事件[28例次（2.5%）]及透析过程中护理干预的次数[51例次（4.5%）]明显少于对照组[110例次（10.2%）,221例次（20.5%）],观察组在透析过程中血流量[（241.6±55.2）mL/min]情况明显好于对照组[（208.0±52.7）mL/min]。结论尿激酶预防滴注法对于半永久性双腔导管尖部血栓及纤维蛋白鞘的治疗效果明显优于尿激酶肝素混合液封管法。展开更多
基金This work was financially supported by the Natural Science Foundation of China(Grant No.52150410408,No.41761048,No.42067002)the Guangxi Science and Technology Program(Grant No.G.K.AA20302020-2).
文摘Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for smallholders.The current research work provides additional options for small plots,as the only income source for low-income farmers in poorer countries,which produce a considerable portion of the agricultural products in some regions of the world.In this research,two novel layouts of a semipermanent sprinkler irrigation system,namely,clock hand(CH)and corner pivot(CP)lateral designs,were designed for a lighter irrigation system to lower the cost requirement.The new techniques were based on a quadrant/full circle movement pattern of manually pivoting laterals,with no/shorter main pipe requirements,which causes a higher system efficiency.These retrofitted layouts were examined in different farms with areas of 0.20 hm^(2),0.81 hm^(2),1.62 hm^(2),and 3.24 hm^(2) in Guangxi,China.This study introduced,analyzed,and compared the layouts with the widespread traditional split lateral method on technical planning,components,implementation,operation details,size optimization,performance evaluation,and economic advantages.In comparison with the traditional system,CH and CP were found to be more user-friendly and cost-effective but slightly complicated in design with higher required manual work.The results revealed a distribution uniformity(LQDU)of 81.0%to 84.0%via the catch can method,lower capital costs(35.0%-45.0%),and lower annual expenses(6.5%-9.8%)for CP and CH,respectively,compared to the split lateral method.The 0.81 hm^(2) and 1.62 hm^(2) farms were found to be the optimum farm sizes for implementation of the new methods for a 25-year project time horizon.The outcomes of this experimental work can encourage small farm owners with limited capital to apply pressurized systems for efficient irrigation and water resource sustainability.
文摘目的观察尿激酶两种不同的应用方法针对血液透析用半永久性双腔导管尖部血栓及纤维蛋白鞘的预防及治疗方法的效果观察。方法选择河北医科大学第三医院血液净化中心2010年1月~12月行半永久性双腔导管置管血液透析患者20例,其中男性11例,女性9例;年龄45～82岁,平均年龄56岁。随机分为2组。共行血液透析2210例次。观察组采用100 kU尿激酶加入100 mL 0.9%NaCl溶液缓慢滴注,对照组采用尿激酶肝素混合液封管,比较透析前导管抽吸不畅事件及透析过程中护理干预情况。结果观察组透析前导管抽吸不畅事件[28例次（2.5%）]及透析过程中护理干预的次数[51例次（4.5%）]明显少于对照组[110例次（10.2%）,221例次（20.5%）],观察组在透析过程中血流量[（241.6±55.2）mL/min]情况明显好于对照组[（208.0±52.7）mL/min]。结论尿激酶预防滴注法对于半永久性双腔导管尖部血栓及纤维蛋白鞘的治疗效果明显优于尿激酶肝素混合液封管法。
