2，4-D处理罗冈甜橙果实后的降解

用质量浓度为200mg/L的2，4D与45%的施宝克（杀菌剂）1000倍液组成的混合溶液浸泡罗岗甜橙果实3min，然后用薄膜袋包装果实，25摄氏度、湿度74%下贮藏，用HPLC方法分析了果实内2，4-D降解情况，结果表明:处理果实放置24H的果皮内2，4-D含量比对照果增加3.29倍；放置24h的果皮内2，4-D含量明显高于果肉。处理的果实放置24h以后，通过从果皮吸收，使果肉内2，4-D含量显著增加，贮藏5d的果肉2，4-D含量达到最高值，贮藏30d的果肉内2，4-D含量为1570.35NG/G,以后显著减少，低于农业部颁发的2，4-D残留量，符合柑橘食用安全性．     

胡柚果实采后枯水机理与防枯技术研究

以胡柚果实为试材,研究果实枯水机理和防枯技术。试验结果表明:贮藏过程果肉组织的衰老和果皮组织生理活性增加同步进行,同位素示踪试验发现,贮藏中后期(3月中旬),果肉组织有糖向果皮组织运转,并开始出现果肉枯水,食用品质下降。SB防枯剂处理可有效防治果肉枯水,提高贮藏后期食用品质,其防枯效果显著优于100mg/L GA_3处理及对照,SB处理的防枯机制可能是通过调节果皮组织和果肉组织的相对生理活性而实现。     

套袋对梨果实Ca、Mg、K营养的影响

为探讨套袋对梨果实矿质营养的影响,采用外灰内黑双层纸袋对黄冠梨、早魁和西子绿3个梨品种的幼果进行套袋处理.结果表明,套袋不显著影响果实单果重.除2006年套袋显著降低黄冠梨果皮Ca含量、Ca/K和Ca/Mg比值,2006、2007年套袋降低西子绿果皮Mg含量以外,其余套袋处理对果皮和果肉的Ca、Mg、K含量均无显著影响.研究表明,套袋影响梨果实对Ca、Mg的吸收,并且套袋对梨果皮Ca、Mg含量的影响大于对果肉的影响;主要降低黄冠梨果皮的Ca含量、Ca/K和Ca/Mg比值,但对果实K含量的影响不显著.     

套袋和膨大剂对黄冠梨钙、果胶含量和果实品质的影响

使用套袋和膨大剂是黄冠梨生产中常用的技术措施,常影响果实品质,导致果面产生褐斑.为揭示套袋和膨大剂对黄冠梨果实的影响机理,本文通过发育早期对黄冠梨幼果进行套袋和果柄涂抹膨大剂处理,结果表明,套袋和使用膨大剂均明显增加果实单果重,分别增加了0.434 2倍和0.7239倍,明显促进冷藏期间果面褐斑的产生,褐斑面积分别是对照的3.85倍和4.38倍.除套袋果实含有较高的淀粉含量外,套袋对果实可溶性固形物、硬度、可滴定酸和可溶性总糖含量影响不显著.套袋后使用膨大剂则明显降低硬度、可滴定酸和淀粉含量,增加固酸比,促进果实成熟.套袋还明显降低果实(主要是果皮)Ca含量,降低果皮中的细胞壁物质、可溶性果胶和原果胶含量,膨大剂则加剧了这些变化;同时,套袋果实果肉中的细胞壁物质、可溶性果胶和原果胶含量较高,膨大剂降低套袋果实果肉中细胞壁物质和原果胶含量,增加可溶性果胶含量.总之,套袋和膨大剂显著降低了黄冠梨果皮中Ca含量,可能是套袋和膨大剂导致果皮褐斑发生的部分机制.     

In_2S_3-Ag/TiO_2三元纳米体系光催化降解2,4-D的实验研究

采用两步沉积法首次合成出新三元纳米材料-In2S3-Ag/TiO2纳米管阵列,并用电子扫描显微镜(SEM)、光致发光光谱仪(PL)等仪器对该三元催化剂进行形貌、元素、晶体结构的表征与光电性能的测试,并将该三元催化体系应用于2,4-二氯苯氧乙酸(2,4-D)的光降解实验.结果表明,In2S3-Ag/TiO2三元纳米材料所特有的两步光激发体系使它的催化降解能力显著提高,在溶液pH为4.23时,140min内可实现对2,4-D 100%的去除;强酸和强碱的环境都不利于三元催化剂In2S3-Ag/TiO2对2,4-D的催化降解.最后对三元催化剂的光催化降解机理进行了探讨.     

1-甲基环丙烯对高温贮藏的香蕉果实抗氧化酶活性的影响

香蕉果实用0.5μL稬-11-甲基环丙烯(1-MCP)处理24 h后,在35℃高温下贮藏,研究1-MCP对香蕉果实丙二醛(MDA)、脯氨酸含量和保护酶系统的影响.结果表明,35℃高温下,香蕉出现明显的"青皮熟"现象,果皮中MDA含量迅速增加.1-MCP处理不同程度地提高了香蕉果皮过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,抑制了果实膜脂过氧化,延缓了MDA含量的上升,增加了脯氨酸的累积,减轻了香蕉热害.1-McP处理果实于35℃下贮藏9 d后移入20℃环境,进一步增加了POD和SO的活性.     

2，4-D对玉米根氧化还原活性的影响及其与根生长和酶活性等的关系

将5mm长的玉米根尖与不同浓度的2,4-二氯苯氧乙酸(2,4-D)一起保温,在加10^-15mol／L至10^9mol/L浓度范围内,根尖对铁氰化钾的还原活性随2,4-D浓度升高而增加;当2,4-D浓度超过10^8mol／L时,还原活性受到抑制,根尖的生长与铁氰化钾还原速率具有很好的相关性,葡萄糖-6-磷酸(G-6-P)脱氢酶活性与铁氰化钾的还原和细胞内NADPH2心水平相平行,ATP酶活性也与上述变化相一致,在低浓度的2,4-D处理下,介质pH下降,高浓度的2,4-D则使介质碱化,上述结果表明2,4-D对玉米垠氧化还原活性和生长速率有显著影响．它的作用是通过活化质子分泌和它对代谢途径的调节实现的。     

采前外源植物激素与采后1-MCP处理对糖心苹果贮藏品质的影响

为解决糖心苹果采后糖心品质快速劣变问题,提高果实贮藏品质,以阿克苏糖心苹果为材料,研究了采前3种外源植物激素与采后1-甲基环丙烯(1-MCP)协同处理对糖心苹果贮藏品质的影响。结果表明,3种处理方式均能在一定程度上提高糖心苹果的贮藏品质。赤霉素与1-MCP处理可有效促进糖心的形成并延缓其消失,贮藏180d后糖心仍有较大面积占比;脱落酸与赤霉素分别协同1-MCP处理均可有效提升果实外观色泽和鲜艳度;生长素与1-MCP处理综合品质调控效果最好,低温贮藏6个月期间可较好地维持果皮和果肉色泽属性,果皮色相角有效降低3.43%,果肉L*值提升1.47%,有效抑制果实呼吸强度6.53%~9.21%,并推迟30d出现呼吸峰,果实失重率和腐烂率分别降低了3.49%和1.12%,分别提升可溶性固形物和维生素C含量1.32%和10.72%。此外,生长素与1-MCP协同处理后,果实硬度提升3.25%,水溶性果胶含量降低19.23%,多聚半乳糖醛酸酶活性始终维持在较低水平,有效延缓了果实采后软化过程。因此,生长素与1-MCP协同处理是一种安全有效的糖心苹果保鲜新技术,应用前景广阔。     

贮藏温度和包装方式对油

研究了不同贮藏温度和包装方式处理组合条件下油果实呼吸强度、品质成分和脂质过氧化作用与耐贮性的关系.结果表明,以(3±1)℃+0.04mm厚度PE薄膜袋包装+100mg/kg保鲜剂Ⅱ号+乙烯吸收剂处理组合贮藏效果最好,能有效抑制果实呼吸强度和品质成分的变化,提高SOD活性和抑制POD活性上升及MDA含量增加,贮藏77 d时,好果率达100%,失重率仅为0.87%,且未发现果肉褐变.呼吸跃变前POD活性上升可作为果实衰老的一个标志,油果肉褐变与果实衰老有关.     

菠萝蜜果实采后糖、酸、蛋白质和V_C含量的变化

以湿包类型菠萝蜜‘301株系’和干包类型菠萝蜜‘75株系’为试材,对常温贮藏条件下果实中的淀粉、可溶性总糖、可滴定有机酸、维生素C和蛋白质含量进行了研究.结果表明:菠萝蜜属于典型的淀粉转化型果实,成熟过程中随着淀粉的不断降解,干、湿包果腱和果肉中的可溶性总糖含量不断增加,分别于采后第5天和第6天、第2天和第3天达到最大之后开始下降.果腱中淀粉的降解和可溶性总糖积累的时间均要早于果肉.干、湿包果肉中的蔗糖含量分别在采后1d和2d增加缓慢,之后迅速增加,分别于采后第2天和第4天达到最大.干、湿包果肉和果腱中的还原糖和有机酸含量、湿包果腱和干包果肉、果腱中的VC含量及湿包果腱中的蛋白质含量均呈现出先升后降的变化趋势,而湿包果肉中的VC和蛋白质含量不断缓慢下降.干包果肉和果腱的蛋白质含量则是先降后升.     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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