Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures...Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.展开更多
水稻覆膜旱作（GCRPS）因具有显著的节水、增产效应而备受关注,但有关覆膜旱作稻田的水均衡关系及蒸腾耗水规律仍然还难以被准确刻画。为此,在湖北省十堰市开展了为期2年的田间试验,并在水稻6个主要生育阶段内对3个灌溉水平（TPRPS,传...水稻覆膜旱作（GCRPS）因具有显著的节水、增产效应而备受关注,但有关覆膜旱作稻田的水均衡关系及蒸腾耗水规律仍然还难以被准确刻画。为此,在湖北省十堰市开展了为期2年的田间试验,并在水稻6个主要生育阶段内对3个灌溉水平（TPRPS,传统淹水种植;GCRPSsat,薄膜覆盖并保持根区土壤接近饱和;GCRPS80%,薄膜覆盖并保持根区平均土壤含水量介于田持的80%-100%）、3个施氮水平（N0,不施氮;N1,150 kg N/hm2尿素;N2,75 kg N/hm2尿素＋75 kg N/hm2鸡粪）共9个处理进行了水量平衡和蒸腾耗水分析。试验研究结果表明：（1）在不减产甚至增产的情况下,覆膜旱作不仅可以抑制深层渗漏与蒸发等非生理耗水,同时还能减少蒸腾耗水,节水效应非常显著,尤其是GCRPS80%;（2）水稻全生育期内的蒸腾耗水变化规律不受水分与氮素处理的影响,总体均表现为生育前期较低,盛期较高,至扬花期达到峰值,之后逐渐衰减;（3）最大分蘖期之前,覆膜增温效应显著促进蒸腾耗水,之后水分胁迫导致情形逆转;（4）扬花期之前,与不施氮相比,施氮可显著促进蒸腾耗水,但两个施氮处理之间的蒸腾耗水差异不大。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61991441 and 62004218)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB01000000)Youth Innovation Promotion Association Chinese Academy of Sciences (Grant No. 2021005)。
文摘Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.
基金partly supported by the National Natural Science Foundation of China(51973027 and 52202218)the Fundamental Research Funds for the Central Universities(2232020A-08)+4 种基金Chang Jiang Scholars Program and the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-03-E00023)to Prof.Qin XDHU Distinguished Young Professor Programthe National Key Research and Development Project(2022YFB4700602)Shanghai Committee of Science and Technology(22ZR1401000)Shanghai Pujiang Program(21PJ1400200)to Prof.Ji D。
基金supported by the National Natural Science Foundation of China(81921004,T2122019,51973096,and 32171325)Tianjin Municipal Science and Technology Bureau(20JCQNJC01720)the Fundamental Research Funds for the Central Universities,Nankai University.
文摘水稻覆膜旱作（GCRPS）因具有显著的节水、增产效应而备受关注,但有关覆膜旱作稻田的水均衡关系及蒸腾耗水规律仍然还难以被准确刻画。为此,在湖北省十堰市开展了为期2年的田间试验,并在水稻6个主要生育阶段内对3个灌溉水平（TPRPS,传统淹水种植;GCRPSsat,薄膜覆盖并保持根区土壤接近饱和;GCRPS80%,薄膜覆盖并保持根区平均土壤含水量介于田持的80%-100%）、3个施氮水平（N0,不施氮;N1,150 kg N/hm2尿素;N2,75 kg N/hm2尿素＋75 kg N/hm2鸡粪）共9个处理进行了水量平衡和蒸腾耗水分析。试验研究结果表明：（1）在不减产甚至增产的情况下,覆膜旱作不仅可以抑制深层渗漏与蒸发等非生理耗水,同时还能减少蒸腾耗水,节水效应非常显著,尤其是GCRPS80%;（2）水稻全生育期内的蒸腾耗水变化规律不受水分与氮素处理的影响,总体均表现为生育前期较低,盛期较高,至扬花期达到峰值,之后逐渐衰减;（3）最大分蘖期之前,覆膜增温效应显著促进蒸腾耗水,之后水分胁迫导致情形逆转;（4）扬花期之前,与不施氮相比,施氮可显著促进蒸腾耗水,但两个施氮处理之间的蒸腾耗水差异不大。
