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Effects of water application uniformity using a center pivot on winter wheat yield, water and nitrogen use efficiency in the North China Plain 被引量:5
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作者 CAI Dong-yu YAN Hai-jun li lian-hao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第9期2326-2339,共14页
In recent years, the use of fertigation technology with center pivot irrigation systems has increased rapidly in the North China Plain (NCP). The combined effects of water and nitrogen application uniformity on the gr... In recent years, the use of fertigation technology with center pivot irrigation systems has increased rapidly in the North China Plain (NCP). The combined effects of water and nitrogen application uniformity on the grain yield, water use efficiency (WUE) and nitrogen use efficiency (NUE) have become a research hotspot. In this study, a two-year field experiment was conducted during the winter wheat growing season in 2016–2018 to evaluate the water application uniformity of a center pivot with two low pressure sprinklers (the R3000 sprinklers were installed in the first span, the corresponding treatment was RS;the D3000 sprinklers were installed in the second span, the corresponding treatment was DS) and a P85A impact sprinkler as the end gun (the corresponding treatment was EG), and to analyze its effects on grain yield, WUE and NUE. The results showed that the water application uniformity coefficients of R3000, D3000 and P85A along the radial direction of the pivot (CUH) were 87.5, 79.5 and 65%, respectively. While the uniformity coefficients along the traveling direction of the pivot (CUC) were all higher than 85%. The effects of water application uniformity of the R3000 and D3000 sprinklers on grain yield were not significant (P>0.05);however, the average grain yield of EG was significantly lower (P<0.05) than those of RS and DS, by 9.4 and 11.1% during two growing seasons, respectively. The coefficients of variation (CV) of the grain yield had a negative correlation with the uniformity coefficient. The CV of WUE was more strongly affected by the water application uniformity, compared with the WUE value, among the three treatments. The NUE of RS was higher than those of DS and EG by about 6.1 and 4.8%, respectively, but there were no significant differences in NUE among the three treatments during the two growing seasons. Although the CUH of the D3000 sprinklers was lower than that of the R3000, it had only limited effects on the grain yield, WUE and NUE. However, the cost of D3000 sprinklers is lower than that of R3000 sprinklers. Therefore, the D3000 sprinklers are recommended for winter wheat irrigation and fertigation in the NCP. 展开更多
关键词 center pivot low pressure sprinkler water application uniformity winter wheat water and nitrogen use efficiency
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典型机械工程安全事故虚拟仿真系统在实践教学中的应用——以架桥机为例
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作者 朱书慧 李连豪 +1 位作者 袁志华 刘婉茹 《科技视界》 2019年第28期58-59,84,共3页
针对典型机械工程安全事故虚拟仿真系统在实践教学应用过程中存在的问题,本文从与课堂知识点结合、教学方法、操作步骤和考核方法等方面展开讨论。结果对合理使用典型机械工程安全事故虚拟仿真系统和丰富《工程力学》实践教学环节场景... 针对典型机械工程安全事故虚拟仿真系统在实践教学应用过程中存在的问题,本文从与课堂知识点结合、教学方法、操作步骤和考核方法等方面展开讨论。结果对合理使用典型机械工程安全事故虚拟仿真系统和丰富《工程力学》实践教学环节场景具有指导意义。 展开更多
关键词 工程安全事故 虚拟仿真 实践教学 应用
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基于WOE-Probit逐步回归的用户跨域行为模式挖掘系统设计 被引量:3
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作者 李连浩 刘岩 +2 位作者 周辛南 赵楠 马丽娜 《电子设计工程》 2020年第17期25-28,32,共5页
为完整掌握电力供应网络中用户节点的跨越调度行为,设计基于WOE-Probit逐步回归的用户跨域行为模式挖掘系统。按照数据挖掘框架的结构类型,连接用户行为处理单元与信息存储模块,实现挖掘系统的硬件执行环境设计。根据跨越行为数据的归... 为完整掌握电力供应网络中用户节点的跨越调度行为,设计基于WOE-Probit逐步回归的用户跨域行为模式挖掘系统。按照数据挖掘框架的结构类型,连接用户行为处理单元与信息存储模块,实现挖掘系统的硬件执行环境设计。根据跨越行为数据的归类原理,提取电网环境中的用户跨域行为指标,再通过构建逐步回归模型的方式,实现挖掘系统的软件执行环境设计,联合相关硬件执行结构,完成基于WOE-Probit逐步回归用户跨域行为模式挖掘系统设计。对比实验结果表明,与传统BIC处理系统相比,应用新型挖掘系统后,用户节点的数据调度频率明显加快,单位时间内电子信息的跨越供应总量也超过9.3×10^14 T,实现核心控制主机对电力供应网络用户节点跨越调度行为的实时监控。 展开更多
关键词 WOE-Probit逐步回归 跨域行为模式 数据归类 行为指标 调度频率 跨越供应量
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农业院校工科《工程力学》实践教学环节困惑与思考
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作者 李连豪 朱书慧 +1 位作者 袁志华 刘婉茹 《科技视界》 2019年第26期64-65,共2页
本文分析农业院校工科《工程力学》实践教学环节中遇到的困境,并思考其解决措施。本文能够为农业院校工科《工程力学》实践教学环节发展提供一定的参考。
关键词 农业院校 工科 工程力学 实践 思考
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典型机械工程安全事故虚拟仿真系统构建——以架桥机为例
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作者 李连豪 朱书慧 +1 位作者 袁志华 刘婉茹 《科技视界》 2019年第27期201-202,共2页
针对在传统工程力学课堂教学活动中,学生与实际安全场景互动性差等问题。本文利用虚拟仿真技术,以架桥机为例,通过知识点模块分析、操作系统和网络条件、用户特殊外置硬件设计,结合技术架构及主要技术开发,构建出典型机械工程安全事故... 针对在传统工程力学课堂教学活动中,学生与实际安全场景互动性差等问题。本文利用虚拟仿真技术,以架桥机为例,通过知识点模块分析、操作系统和网络条件、用户特殊外置硬件设计,结合技术架构及主要技术开发,构建出典型机械工程安全事故虚拟仿真系统。可大大提高学生在实际机械安全问题中的互动性。 展开更多
关键词 虚拟仿真 安全事故 架桥机 系统 构建
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