小麦叶片的电阻抗图谱参数对PEG胁迫的响应

为了解水分胁迫下小麦叶片细胞膜变化的一些电参数特性,应用电阻抗图谱的方法研究小麦叶片对PEG溶液不同渗透势的反应,测定了不同渗透势下叶片的胞外电阻、胞内电阻、弛豫时间及弛豫时间的分布系数的数值,并应用回归分析和相关分析对电阻抗参数与渗透势的关系及电阻抗参数之间关系进行了分析。结果表明,随着PEG溶液渗透势的增加,胞外电阻、胞内电阻和弛豫时间减小,弛豫时间分布系数表现为先增大后减小;随着胁迫时间的增加,胞外电阻和胞内电阻在各个渗透势的变化规律不一致,弛豫时间增大,弛豫时间分布系数先增加后减小。胞外电阻、胞内电阻和弛豫时间对不同的渗透势具有显著或极显著的线性关系。     

低温胁迫对小麦叶片电阻抗图谱参数的影响

用电阻抗图谱的方法研究了小麦叶片在低温胁迫下的变化．测定了在设计的7个温度水平,盆栽小麦叶片的电阻、电抗以及相对电导率的变化,拟合了叶片在不同温度的胞外电阻、胞内电阻、弛豫时间和弛豫时间分布系数．结果表明：随着温度降低,叶片的胞外电阻、弛豫时间、弛豫时间分布系数减小,胞内电阻增加．用胞外电阻表示的小麦叶片的抗寒性为-14．10℃,与用相对电导率表示的抗寒性（-14．43℃）结果极为接近．胞外电阻是冷冻处理后确定小麦叶片抗寒性最适合的参数．     

小麦叶片电阻抗图谱参数对重金属胁迫的响应

 为了研究小麦在重金属胁迫下电阻抗图谱参数的规律,测定了小麦叶片在重金属离子Zn²⁺、Pb²⁺、Cr（Ⅲ）、Cu²⁺、Ni²⁺、Cr（Ⅵ）6种离子胁迫下的胞外电阻、胞内电阻、弛豫时间和弛豫时间分布系数,并通过回归分析建立上述电阻抗图谱参数与重金属离子浓度之间的关系。研究表明,随着重金属离子浓度的增加,小麦叶片的胞外电阻和弛豫时间表现为减小,胞内电阻和弛豫时间分布系数增加,与其他4种离子相比,Cu²⁺和Cr(Ⅵ)离子更能显著减小胞外电阻和弛豫时间的数值,可以用弛豫时间来预测小麦叶片受重金属毒害的程度。研究表明,弛豫时间的变化基本满足logistic模型。     

冬小麦水分生态生理的研究

本文研究了冬小麦不同生育期内水分的生态生理指标。冬小麦全生育期有三个吸水高峰期,分蘖盛期至越冬前出现第一峰值;拔节抽穗期出现第二峰值(强峰);开花灌浆期出现第三峰值。拔节、抽搐、开花灌浆期是冬小麦的需水临界期,在浇水与控水处理条件下,不同抗(耐)旱品种叶组织水势有明显的差异,控水组的叶水势明显地低于浇水处理组。在控水(干旱)状态下,植株体内脯氨酸浓度明显地高于浇水处理组。在水分胁迫状态下,叶片气孔导度呈现出偏低趋势。如果土壤水分得不到补充,浇水组的气孔导度值将与控水组的气孔导度相近。     

小麦品种抗旱性鉴定方法的研究

一般农作物在抗旱性的生态型划分上属于中生植物类型。探讨中生植物抗旱性的规律,研究鉴定中生植物抗旱性强弱的方法,对于干旱地区的农业生产是十分重要的。小麦是一种耗水量较大的中生植物。在通常情况下,它的蒸腾系数约在450-550左右。在它的生长发育过程中,有两个时期对缺水最为敏感,特称为水分临界期。从分蘖末期到抽穗期为第一临界期;灌浆期到乳熟期为第二临界期。这两个时期遇到干旱,减产就最严重。农谚说“麦怕掐脖旱”、“灌浆遇旱风、麦秕穗子空”形象地刻画出小麦临界期缺水的受害症状。     

土壤水分胁迫与调控对冬小麦生育指标的影响

针对干旱地区有限水资源和发展节水灌溉实际,采用田间试验方法探讨了土壤水分胁迫与调控对冬小麦矿质营养吸收、干物质累积、产量形成和籽粒营养品质等的影响．试验结果表明：在冬小麦各个生育期,土壤水分胁迫与调控均会影响冬小麦对矿质营养的吸收和干物质累积等;各个生育期相应的土壤水分胁迫指标(占田持的百分比),苗期为60％,返青期为60％,拔节-抽穗期为65％,抽穗-灌浆期为65％,灌浆-成熟期为55％;水分胁迫对冬小麦籽粒的N,P,K,蛋白质,粗脂肪和淀粉等营养品质的影响不大,苗期、灌浆-成熟期水分胁迫对产量的影响最小,而拔节-抽穗期水分胁迫对产量的影响最大,故拔节-抽穗期为冬小麦缺水敏感期,水分胁迫应尽量避免．     

PEG处理对甘薯叶片渗透调节物质的影响

用不同浓度的ＰＥＧ对甘薯进行根际干旱处理，研究了叶片中几种主要渗透调节物质的变化．在轻度水分胁迫下，脯氨酸和Ｋ￣＋的反映较敏感，可溶性糖和其他游离氨基酸几乎平行增加．抗旱性较强的渝薯２０渗透调节物质（脯氨酸除外）的积累均高于抗旱性弱的农大红，对渗透调节的贡献由高至低依次为：总游离氨基酸＞Ｋ￣＋＞可溶性糖＞脯氨酸；并随水分胁迫的加剧而渐次减弱．脯氨酸积累的数量与品种抗旱性无关．     

水分胁迫下不同抗旱性冬小麦幼苗叶片气孔的扫描电镜观察

本文以北方常见的两种冬小麦--冀麦7号和 C_(609) 为材料,用25%PEG(聚乙二醇)溶液对其幼苗进行水分胁迫处理,对在不同时间水分胁迫下的小麦幼苗叶片气孔进行扫描电镜观察,试图说明小麦幼苗气孔的变化情况是与缺水的程度、与不同抗旱性的小麦品种密切相关。并想为以后测定不同品种植物的抗旱性提供一种鉴定的方法。     

不同生育期水分胁迫对葡萄生长生理特性的影响

为了研究不同生育期水分胁迫对鲜食葡萄光合作用和果实品质的影响,以玫瑰香葡萄为对象开展设施研究,在萌芽期、新梢生长期、开花期、果实膨大期、着色期以及全生育期分别进行水分胁迫,并以全生育期充分灌溉作为对照组,研究不同生育期水分胁迫对葡萄光合特性、产量和果实品质的影响。结果表明：新梢生长期葡萄叶片净光合速率受水分胁迫影响最小,与对照组相比减小8.96%;果实膨大期葡萄叶片净光合速率受水分胁迫影响最大,与对照组相比减小13.14%;萌芽期水分胁迫提产效果显著,可增产9.87%;着色期水分胁迫有利于果实维生素C以及还原糖的积累,降低可滴定酸的含量,提升果实品质,且对产量无显著影响。     

水分胁迫对全生育期水、旱稻SOD活性的影响及其与抗旱性的关系

以５种抗旱性不同的水、旱稻品种在水分胁迫下全生育期的茎叶为实验材料，采用ＮＢＴ光还原法测定ＳＯＤ活性，探讨不同品种全生育期的不同阶段对水分胁迫的反应及其与抗旱性的关系．结果表明，受到水分胁迫的水、旱稻ＳＯＤ活性均高于对照；孕穗期和抽穗期是水分敏感期，在孕穗期ＳＯＤ上升１９．６０％，抽穗期上升６．４０％；成熟期ＳＯＤ活性平均下降１１．７３％，不同品种在此期间ＳＯＤ活性下降幅度有明显差别，旱稻品种下降１７％～２６％，水稻品种下降７％左右     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with