Waterlogging and low application efficiency are the main problems inherent with surface irrigation in the Nile Delta. Develop surface irrigation using gated pipes (GP) is a new method to be used to distribute water in...Waterlogging and low application efficiency are the main problems inherent with surface irrigation in the Nile Delta. Develop surface irrigation using gated pipes (GP) is a new method to be used to distribute water into furrow irrigated fields as strategy based on water saving. Laboratory calibration was conducted out to evaluate the hydraulic characteristics of pipe gates. Field experiments were conducted at the Experimental Farm of the Agriculture Faculty, Minufiya University during 2013 and 2014 seasons to evaluate the performance of utilize gated pipes technique for irrigating five maize varieties (S.C 10, S.C 130, S.C 131, S.C 2031 and T.W.C 321). The results revealed that the highest amount of water applied was with traditional surface irrigation (6423.81 m3·ha-1. Use of gated pipes system GP1 as compared to traditional irrigation reduced water application by 923.81 m3·ha-1 with grain and stover yields increases of 5.7% and 3.4%, respectively. Traditional irrigation system achieved lowest irrigation performance parameters compared to gated pipes systems. Maize physiological attributes, yield, water use efficiency (WUE) and nitrogen accumulation were significantly decreased by either deficit or surplus irrigation than of GP1 rate. S.C 2031 variety significantly surpassed other varieties in abovementioned traits. Significant interaction effects were detected in both seasons. Maize varieties respond differently to irrigation systems. The highest values of grain yield (11062.6 and 10911.8 kg·ha-1 and stover yield (13639.0 and 13902.2 kg·ha-1) were obtained by S.C 2031 irrigated with GP1 system in both seasons. From the above mentioned results, it is concluded that the gated pipes technique is better than traditional irrigation for improving WUE and maize productivity under Nile Delta conditions.展开更多
This paper presents a nonlinear profile order scheme for three-dimensional（3D） hybrid radial acquisition applied to self-gated, free-breathing cardiac cine magnetic resonance imaging（MRI）. In self-gated, free-brea...This paper presents a nonlinear profile order scheme for three-dimensional（3D） hybrid radial acquisition applied to self-gated, free-breathing cardiac cine magnetic resonance imaging（MRI）. In self-gated, free-breathing cardiac cine MRI,respiratory and cardiac motions are unpredictable during acquisition, especially for retrospective reconstruction. Therefore,the non-uniformity of the k-space distribution is an issue of great concern during retrospective self-gated reconstruction. A nonlinear profile order with varying azimuthal increments was provided and compared with the existing golden ratio-based profile order. Optimal parameter values for the nonlinear formula were chosen based on simulations. The two profile orders were compared in terms of the k-space distribution and phantom and human image results. An approximately uniform distribution was obtained based on the nonlinear profile order for persons with various heart rates and breathing patterns.The nonlinear profile order provides more stable profile distributions and fewer streaking artifacts in phantom images. In a comparison of human cardiac cine images, the nonlinear profile order provided results comparable to those provided by the golden ratio-based profile order, and the images were suitable for diagnosis. In conclusion, the nonlinear profile order scheme was demonstrated to be insensitive to various motion patterns and more useful for retrospective reconstruction.展开更多
文摘Waterlogging and low application efficiency are the main problems inherent with surface irrigation in the Nile Delta. Develop surface irrigation using gated pipes (GP) is a new method to be used to distribute water into furrow irrigated fields as strategy based on water saving. Laboratory calibration was conducted out to evaluate the hydraulic characteristics of pipe gates. Field experiments were conducted at the Experimental Farm of the Agriculture Faculty, Minufiya University during 2013 and 2014 seasons to evaluate the performance of utilize gated pipes technique for irrigating five maize varieties (S.C 10, S.C 130, S.C 131, S.C 2031 and T.W.C 321). The results revealed that the highest amount of water applied was with traditional surface irrigation (6423.81 m3·ha-1. Use of gated pipes system GP1 as compared to traditional irrigation reduced water application by 923.81 m3·ha-1 with grain and stover yields increases of 5.7% and 3.4%, respectively. Traditional irrigation system achieved lowest irrigation performance parameters compared to gated pipes systems. Maize physiological attributes, yield, water use efficiency (WUE) and nitrogen accumulation were significantly decreased by either deficit or surplus irrigation than of GP1 rate. S.C 2031 variety significantly surpassed other varieties in abovementioned traits. Significant interaction effects were detected in both seasons. Maize varieties respond differently to irrigation systems. The highest values of grain yield (11062.6 and 10911.8 kg·ha-1 and stover yield (13639.0 and 13902.2 kg·ha-1) were obtained by S.C 2031 irrigated with GP1 system in both seasons. From the above mentioned results, it is concluded that the gated pipes technique is better than traditional irrigation for improving WUE and maize productivity under Nile Delta conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.81501463,61671026,81571669,and 81671853)the Natural Science Foundation of Guangdong Province,China(Grant No.2014A030310360)+3 种基金Guangdong Innovative Research Team Program of China(Grant No.2011S013)the Basic Research Project of Shenzhen City,China(Grant Nos.JCYJ20140417113430639 and JCYJ20160429172357751)the High-level Oversea Talent Program of Shenzhen City,China(Grant No.KQJSCX20160301144248)Beijing Center for Mathematics and Information Interdisciplinary Sciences of China
文摘This paper presents a nonlinear profile order scheme for three-dimensional（3D） hybrid radial acquisition applied to self-gated, free-breathing cardiac cine magnetic resonance imaging（MRI）. In self-gated, free-breathing cardiac cine MRI,respiratory and cardiac motions are unpredictable during acquisition, especially for retrospective reconstruction. Therefore,the non-uniformity of the k-space distribution is an issue of great concern during retrospective self-gated reconstruction. A nonlinear profile order with varying azimuthal increments was provided and compared with the existing golden ratio-based profile order. Optimal parameter values for the nonlinear formula were chosen based on simulations. The two profile orders were compared in terms of the k-space distribution and phantom and human image results. An approximately uniform distribution was obtained based on the nonlinear profile order for persons with various heart rates and breathing patterns.The nonlinear profile order provides more stable profile distributions and fewer streaking artifacts in phantom images. In a comparison of human cardiac cine images, the nonlinear profile order provided results comparable to those provided by the golden ratio-based profile order, and the images were suitable for diagnosis. In conclusion, the nonlinear profile order scheme was demonstrated to be insensitive to various motion patterns and more useful for retrospective reconstruction.
