为探究雨养和灌溉条件下氮肥后移对冬小麦面粉加工品质的影响及其谷蛋白形成机制,本研究选用强筋小麦品种中麦886(ZM886)和中筋小麦品种中麦30(ZM30)为试验材料,在雨养处理(W)和灌溉处理(D)条件下,总施氮量为210 kg hm^(-2)的基础上设置...为探究雨养和灌溉条件下氮肥后移对冬小麦面粉加工品质的影响及其谷蛋白形成机制,本研究选用强筋小麦品种中麦886(ZM886)和中筋小麦品种中麦30(ZM30)为试验材料,在雨养处理(W)和灌溉处理(D)条件下,总施氮量为210 kg hm^(-2)的基础上设置2个追氮处理:常规氮肥处理(N1:底肥50%+拔节肥50%)和氮肥后移处理(N2:底肥50%+拔节肥30%+孕穗肥20%),研究其对冬小麦籽粒谷蛋白大聚合体(GMP)形成和面粉加工品质的影响。试验结果表明,2小麦品种产量最大值均出现在WN2处理,其中ZM30在WN2处理下产量较其他处理平均提高12.36%(2021—2022年)和13.97%(2022—2023年),ZM886同期分别提高9.85%和18.31%。在花后10 d检测到籽粒中高分子量谷蛋白亚基(HMW-GS)和低分子量谷蛋白亚基(LMW-GS),ZM886在DN2处理下HMW-GS、LMW-GS、free-SH、-S-S-含量最高,ZM30则在WN2处理达到峰值。花后30 d检测到2小麦品种籽粒GMP的存在,ZM886在DN2下较其他处理增高5.40%~33.90%,ZM30在WN2下增高2.50%~14.70%,同时分别在2处理下增加了GMP大颗粒体积和表面积百分比,从而不同程度地提高面粉加工品质。小麦籽粒GMP含量与HMW-GS含量和LMW-GS含量呈正相关,ZM886籽粒GMP含量与面团形成时间和稳定时间呈正相关,但与产量呈负相关;ZM30籽粒GMP含量与产量呈极显著正相关,但与吸水率呈负相关。综上,本试验条件下,氮肥后移通过调控谷蛋白亚基合成,提升GMP含量,优化GMP粒径分布。因小麦产量而言,适宜的水氮配置为:灌溉处理下,氮肥施用底肥50%+拔节肥30%+孕穗肥20%;因小麦品质而言,适宜的水氮配置因品种类型而异:强筋小麦中麦886为在雨养处理下,氮肥施用底肥50%+拔节肥30%+孕穗肥20%,中筋小麦中麦30为在灌溉处理下,氮肥施用底肥50%+拔节肥30%+孕穗肥20%。展开更多
The existing analytical models for umbrella arch method(UAM)based on elastic foundation beams often overlook the influence of the surrounding soil beyond the beam edges on the shear stresses acting on the beam.Consequ...The existing analytical models for umbrella arch method(UAM)based on elastic foundation beams often overlook the influence of the surrounding soil beyond the beam edges on the shear stresses acting on the beam.Consequently,such models fail to adequately reflect the continuity characteristics of soil deformation.Leveraging the Pasternak foundation-Euler beam model,this study considers the generalized shear force on the beam to account for the influence of soil outside the beam ends on the shear stress.An analytical model for the deformation and internal forces of finite-length beams subjected to arbitrary loads is derived based on the initial parameter method under various conditions.The mechanical model of the elastic foundation beam for advanced umbrella arch under typical tunnel excavation cycles is established,yielding analytical solutions for the longitudinal response of the umbrella arch.The reliability of the analytical model is verified with the existing test data.The improved model addresses anomalies in existing models,such as abnormal upward deformation in the loosened segment and maximum deflection occurring within the soil mass.Additionally,dimensionless characteristic parameters reflecting the relative stiffness between the umbrella arch structure and the foundation soil are proposed.Results indicate that the magnitude of soil characteristic parameters significantly influences the deformation and internal forces of the umbrella arch.Within common ranges of soil values,the maximum deformation and internal forces of the umbrella arch under semi-logarithmic coordinates exhibit nearly linear decay with decreasing soil characteristic parameters.The impact of tunnel excavation height on the stress of unsupported sections of the umbrella arch is minor,but it is more significant for umbrella arch buried within the soil mass.Conversely,the influence of tunnel excavation advance on the umbrella arch is opposite.展开更多
A generalized multiple-mode prolate spherical wave functions (PSWFs) multi-carrier with index modulation approach is proposed with the purpose of improving the spectral efficiency of PSWFs multi-carrier systems. The p...A generalized multiple-mode prolate spherical wave functions (PSWFs) multi-carrier with index modulation approach is proposed with the purpose of improving the spectral efficiency of PSWFs multi-carrier systems. The proposed method,based on the optimized multi-index modulation, does not limit the number of signals in the first and second constellations and abandons the concept of limiting the number of signals in different constellations. It successfully increases the spectrum efficiency of the system while expanding the number of modulation symbol combinations and the index dimension of PSWFs signals. The proposed method outperforms the PSWFs multi-carrier index modulation method based on optimized multiple indexes in terms of spectrum efficiency, but at the expense of system computational complexity and bit error performance. For example, with n=10 subcarriers and a bit error rate of 1×10^(-5),spectral efficiency can be raised by roughly 12.4%.展开更多
为提高局部阴影条件下光伏发电的能量利用率,提出一种改进型快速全局最大功率点跟踪(global maximum power point tracking,GMPPT)算法.首先,研究局部阴影条件下光伏阵列的输出特性,并根据光伏阵列输出曲线中膝点与开路电压的关系,将其...为提高局部阴影条件下光伏发电的能量利用率,提出一种改进型快速全局最大功率点跟踪(global maximum power point tracking,GMPPT)算法.首先,研究局部阴影条件下光伏阵列的输出特性,并根据光伏阵列输出曲线中膝点与开路电压的关系,将其划分为恒流区和恒压区;其次,分析传统的最大功率梯形(maximum power trapezium,MPT)算法和以MPT算法为基础的改进型快速GMPPT算法的工作原理,改进型快速GMPPT算法利用电压的动态上、下限来限定搜索区间,并跳过调整时间较长的恒流区,以提高跟踪速度;最后,通过仿真与实验验证算法的有效性.实验结果表明:改进型快速GMPPT算法的最短跟踪时间为4.0 s,扫描电压与能量损失分别为17.34 V和98.19 J;与传统全局扫描算法相比,跟踪时间缩短68.25%,扫描电压降低74.86%,能量损失减少58.19%;与MPT算法相比,跟踪时间缩短68.00%,扫描电压降低75.63%,能量损失减少62.31%.展开更多
文摘为探究雨养和灌溉条件下氮肥后移对冬小麦面粉加工品质的影响及其谷蛋白形成机制,本研究选用强筋小麦品种中麦886(ZM886)和中筋小麦品种中麦30(ZM30)为试验材料,在雨养处理(W)和灌溉处理(D)条件下,总施氮量为210 kg hm^(-2)的基础上设置2个追氮处理:常规氮肥处理(N1:底肥50%+拔节肥50%)和氮肥后移处理(N2:底肥50%+拔节肥30%+孕穗肥20%),研究其对冬小麦籽粒谷蛋白大聚合体(GMP)形成和面粉加工品质的影响。试验结果表明,2小麦品种产量最大值均出现在WN2处理,其中ZM30在WN2处理下产量较其他处理平均提高12.36%(2021—2022年)和13.97%(2022—2023年),ZM886同期分别提高9.85%和18.31%。在花后10 d检测到籽粒中高分子量谷蛋白亚基(HMW-GS)和低分子量谷蛋白亚基(LMW-GS),ZM886在DN2处理下HMW-GS、LMW-GS、free-SH、-S-S-含量最高,ZM30则在WN2处理达到峰值。花后30 d检测到2小麦品种籽粒GMP的存在,ZM886在DN2下较其他处理增高5.40%~33.90%,ZM30在WN2下增高2.50%~14.70%,同时分别在2处理下增加了GMP大颗粒体积和表面积百分比,从而不同程度地提高面粉加工品质。小麦籽粒GMP含量与HMW-GS含量和LMW-GS含量呈正相关,ZM886籽粒GMP含量与面团形成时间和稳定时间呈正相关,但与产量呈负相关;ZM30籽粒GMP含量与产量呈极显著正相关,但与吸水率呈负相关。综上,本试验条件下,氮肥后移通过调控谷蛋白亚基合成,提升GMP含量,优化GMP粒径分布。因小麦产量而言,适宜的水氮配置为:灌溉处理下,氮肥施用底肥50%+拔节肥30%+孕穗肥20%;因小麦品质而言,适宜的水氮配置因品种类型而异:强筋小麦中麦886为在雨养处理下,氮肥施用底肥50%+拔节肥30%+孕穗肥20%,中筋小麦中麦30为在灌溉处理下,氮肥施用底肥50%+拔节肥30%+孕穗肥20%。
基金Projects(52008403,52378421)supported by the National Natural Science Foundation of ChinaProject(2022-Key-10)supported by the Science and Technology Research and Development Program Project of China Railway Group LimitedProject(202207)supported by the Hunan Provincial Transportation Science and Technology,China。
文摘The existing analytical models for umbrella arch method(UAM)based on elastic foundation beams often overlook the influence of the surrounding soil beyond the beam edges on the shear stresses acting on the beam.Consequently,such models fail to adequately reflect the continuity characteristics of soil deformation.Leveraging the Pasternak foundation-Euler beam model,this study considers the generalized shear force on the beam to account for the influence of soil outside the beam ends on the shear stress.An analytical model for the deformation and internal forces of finite-length beams subjected to arbitrary loads is derived based on the initial parameter method under various conditions.The mechanical model of the elastic foundation beam for advanced umbrella arch under typical tunnel excavation cycles is established,yielding analytical solutions for the longitudinal response of the umbrella arch.The reliability of the analytical model is verified with the existing test data.The improved model addresses anomalies in existing models,such as abnormal upward deformation in the loosened segment and maximum deflection occurring within the soil mass.Additionally,dimensionless characteristic parameters reflecting the relative stiffness between the umbrella arch structure and the foundation soil are proposed.Results indicate that the magnitude of soil characteristic parameters significantly influences the deformation and internal forces of the umbrella arch.Within common ranges of soil values,the maximum deformation and internal forces of the umbrella arch under semi-logarithmic coordinates exhibit nearly linear decay with decreasing soil characteristic parameters.The impact of tunnel excavation height on the stress of unsupported sections of the umbrella arch is minor,but it is more significant for umbrella arch buried within the soil mass.Conversely,the influence of tunnel excavation advance on the umbrella arch is opposite.
基金supported by the China National Postdoctoral Program for Innovative Talents(BX20200039)the Special Fund Project of“Mount Taishan Scholars”Construction Project in Shandong Province(ts20081130).
文摘A generalized multiple-mode prolate spherical wave functions (PSWFs) multi-carrier with index modulation approach is proposed with the purpose of improving the spectral efficiency of PSWFs multi-carrier systems. The proposed method,based on the optimized multi-index modulation, does not limit the number of signals in the first and second constellations and abandons the concept of limiting the number of signals in different constellations. It successfully increases the spectrum efficiency of the system while expanding the number of modulation symbol combinations and the index dimension of PSWFs signals. The proposed method outperforms the PSWFs multi-carrier index modulation method based on optimized multiple indexes in terms of spectrum efficiency, but at the expense of system computational complexity and bit error performance. For example, with n=10 subcarriers and a bit error rate of 1×10^(-5),spectral efficiency can be raised by roughly 12.4%.
文摘为提高局部阴影条件下光伏发电的能量利用率,提出一种改进型快速全局最大功率点跟踪(global maximum power point tracking,GMPPT)算法.首先,研究局部阴影条件下光伏阵列的输出特性,并根据光伏阵列输出曲线中膝点与开路电压的关系,将其划分为恒流区和恒压区;其次,分析传统的最大功率梯形(maximum power trapezium,MPT)算法和以MPT算法为基础的改进型快速GMPPT算法的工作原理,改进型快速GMPPT算法利用电压的动态上、下限来限定搜索区间,并跳过调整时间较长的恒流区,以提高跟踪速度;最后,通过仿真与实验验证算法的有效性.实验结果表明:改进型快速GMPPT算法的最短跟踪时间为4.0 s,扫描电压与能量损失分别为17.34 V和98.19 J;与传统全局扫描算法相比,跟踪时间缩短68.25%,扫描电压降低74.86%,能量损失减少58.19%;与MPT算法相比,跟踪时间缩短68.00%,扫描电压降低75.63%,能量损失减少62.31%.
