凋落物及根系输入变化对喀斯特地区檵木土壤养分和胞外酶的影响

凋落物输入变化能改变土壤的理化性质，显著影响土壤碳氮磷养分含量和胞外酶活性，引起胞外酶活性化学计量特征的变化。为进一步明确喀斯特地区凋落物输入变化对土壤养分含量、胞外酶活性及其化学计量的影响，并探究胞外酶与环境因子间的生态响应规律，本文以喀斯特地区檵木老龄林土壤为研究对象，布设凋落物添加和去除试验，通过对土壤养分及胞外酶活性的测定，运用生态化学计量学理论与方法，系统研究土壤中6种胞外水解酶(β-1,4-葡糖苷酶(BG)、β-1,4-木糖苷酶(BX)、纤维素水解酶(CBH)、β-1,4-乙酰氨基葡萄糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)、酸性磷酸酶(AP))和2种胞外氧化酶(过氧化氢酶(CAT)、多酚氧化酶(PPO))活性及其化学计量的影响，并分析它们与土壤环境因子之间的相关性。结果表明：1)与对照(CK)相比，土壤SOC、TN含量在凋落物添加下具有显著性变化，去除凋落物根系(ABR)和双倍凋落物添加(AD)处理的土壤C∶N值显著增大；2)过氧化氢酶活性CK处理下最高，且与其他处理具有显著性差异；多酚氧化酶活性ABR处理最高，且与AD和BR处理差异性显著；土壤胞外酶活性的矢量角度小于...     

去除和添加凋落物对马尾松×红锥混交林土壤呼吸的影响

为探讨凋落物输入量改变对马尾松×红锥混交林碳排放的影响,以马尾松×红锥异龄混交林为研究对象,通过添加和去除凋落物人为地改变碳输入,研究凋落物处理方式对土壤呼吸的影响。结果表明:(1)去除凋落物可降低土壤湿度、提高土壤温度,而添加凋落物则提高土壤湿度、降低土壤温度。去除凋落物使土壤年均呼吸速率显著降低27.88%,而添加凋落物则使土壤年均呼吸速率显著增加34.02%。(2)去除凋落物能降低四季的土壤呼吸累积排放量,而添加凋落物则提高四季的土壤呼吸累积排放量。对照、去除和添加凋落物的土壤呼吸的年累积排放量(以C计)分别为(9.51±0.12) t·hm~(-2)、(6.88±0.21) t·hm~(-2)和(12.70±0.53) t·hm~(-2),可见去除凋落物使土壤呼吸年累积排放量降低27.66%,而添加凋落物使土壤呼吸年累积排放量提高33.54%。(3)不同凋落物处理方式下土壤呼吸速率与土壤温度均呈显著相关,土壤温度解释了土壤呼吸速率变异程度的74.26%～94.28%。去除凋落物增加了土壤呼吸温度敏感性系数Q10值,而添加凋落物则降低Q10值。凋落物处理方式对马尾松×红锥异龄混交林土壤呼吸产生了显著影响,证明凋落物对于改变森林生态系统土壤呼吸和碳循环具有重要作用。     

内生真菌对杉木人工林下土壤酶活性的影响

通过筛选能够提高土壤酶活性的菌株及添加方式,探讨内生真菌对杉木(Cunninghamia lanceolata)人工林下土壤酶活性的影响,以促进叶凋落物分解.采用3株杉木内生真菌青霉菌(Penicillium sp.)CG2 (A菌)、黄色镰刀菌(Fusarium culmorum)AY13(B菌)、踝节霉菌(Talaromyces sp.)AJ14(C菌)的单菌株和混菌株,按不同方式(菌丝、菌液)浇施于装有杉木凋落叶和土壤的盆钵内,在处理10,60,120d后分别取样,测定土壤酶活性和凋落叶质量的变化情况.结果表明:多酚氧化酶活性在混菌丝处理下始终保持在较高水平,菌丝和菌液处理均提高了脲酶和酸性磷酸酶活性,蔗糖酶活性前期(10d)高于后期(120d).C菌液处理下(120d)纤维素酶、木质素过氧化物酶和酸性磷酸酶活性均最高,与对照存在显著差异(p0.05),分别比对照高56.46%,43.97%和163.65%;BC混菌丝处理下(120d)多酚氧化酶活性最高,比对照高36.75%(p0.05);AB混菌丝处理下(10d)蔗糖酶活性最高,比对照高162.90%(p0.05);AC混菌液处理下(120d)脲酶活性最高,比对照高69.78%(p0.05).凋落叶质量损失率与纤维素酶、脲酶、酸性磷酸酶、木质素过氧化物酶以及混菌处理的多酚氧化酶活性变化趋势相同,菌株种类、添加方式、分解时间及其交互作用对酶活性有显著影响.综上所述,C菌液能最有效地提高纤维素酶、木质素过氧化物酶和酸性磷酸酶活性,BC和AB混菌丝分别对提高多酚氧化酶和蔗糖酶活性最有效,AC混菌液则能最有效地提高脲酶活性.     

露天矿区人工林凋落物的木质纤维素酶活性和真菌多样性研究

使用传统酶学分析方法与分子生物学PCR-DGGE方法相结合,对安太堡露天矿区复垦地人工林凋落物的木质纤维素酶活性和真菌菌群的多样性进行了研究。结果表明,沙棘-刺槐-柠条-沙枣混交林下凋落物的锰过氧化物酶、羧甲基纤维素酶和滤纸酶的活性最高,青杄-白杄混交林凋落物的漆酶活性最高,不同组成的凋落物附生真菌群落多样性差异明显,真菌群落结构发生了显著变化。     

多菌灵对新疆灰漠土壤中六种酶活性的影响

采用室内模拟的方法研究5种浓度多菌灵（0、2．5、5．0、10．0和20．0mg·kg^-1干土）对土壤中纤维素酶、蔗糖酶、脲酶、碱性磷酸酶、过氧化氢酶、蛋白酶活性的影响。结果表明：土壤纤维素酶活性随多菌灵浓度的增加（2．5～20．0mg·kg^-1）而升高;多菌灵对脲酶也有显著的激活作用,其中10mg·kg^-1多菌灵处理对脲酶的激活率最高。多菌灵对土壤碱性磷酸酶和蛋白酶活性的影响随多菌灵处理浓度和时间变化而变化。多菌灵处理5d内,土壤蔗糖酶活性显著降低,且抑制率与多菌灵浓度呈正相关,土壤过氧化氢酶活性受多菌灵抑制作用显著,尤其是在多菌灵处理26d以后,土壤过氧化氢酶活性随多菌灵浓度的增加显著降低。因此,可以用蔗糖酶活性来评价多菌灵施用后1～5d在土壤中的残留情况,以过氧化氢酶活性来评价多菌灵施用后26～47d在土壤中的残留情况。     

凋落物和根系去除对土壤N2O排放的影响——整合分析

基于全球范围内开展的凋落物去除和根系去除实验,获取61对土壤N₂O排放数据,通过整合分析方法,定量地评估去除凋落物和根系对土壤N₂O排放的影响与调控因素。结果表明,去除凋落物处理后,土壤N₂O排放显著降低(-16.5%);去除根系处理后,土壤N₂O排放显著增加(+131.6%)。凋落物和根系去除情况下,N₂O排放的变化与土壤水分和硝态氮含量的变化具有显著的正相关关系,表明土壤水分和硝态氮含量的变化是土壤N₂O排放响应植物输入降低的主要调控因素。研究结果揭示了凋落物去除和根系去除对土壤N₂O排放的影响与调控因素,有利于理解未来全球变化背景下植物输入的改变如何影响土壤N₂O的排放。     

锰及锰镉复合污染对锰矿区茶园土壤酶活性的影响

研究广西八一锰矿恢复区茶园土壤重金属(锰、镉)污染浓度与酶活性的关系,并分析锰离子单一处理和锰镉复合处理条件下土壤酶活性的变化情况.结果表明,锰单一污染与锰镉复合污染对土壤酶活性产生的影响有所不同.锰单一污染对锰矿区土壤酶活性的抑制效应顺序为:过氧化氢酶＞蔗糖酶＞脲酶;锰镉复合污染对锰矿区土壤酶活性的抑制效应顺序为:蔗糖酶＞过氧化氢酶＞脲酶.其中,锰镉复合污染对蔗糖酶表现出协同抑制负效应的特征,对过氧化氢酶和脲酶则表现出不同程度的拮抗作用.建议以过氧化氢酶和蔗糖酶的活性作为评价和预测锰矿恢复区茶园土壤锰镉污染状况的敏感指标.     

生物覆盖对银杏用材林土壤酶活性的影响

生物覆盖是改善土壤性质和提高作物产量的一种重要土壤管理措施。笔者以东台林场银杏(Ginkgo biloba L.)用材林地为研究对象,采用随机区组试验设计,研究了覆盖材料(小麦秸秆、稻草秸秆和玉米秸秆)和覆盖量(2、4和6 kg/m2玉米秸秆)对表层土壤(0~10 cm)中脲酶、碱性磷酸酶活性、蔗糖酶和过氧化氢酶活性的影响。结果表明:3种生物覆盖材料均不同程度地提高了土壤中脲酶、碱性磷酸酶、蔗糖酶和过氧化氢酶的活性,以玉米秸秆和稻草秸秆覆盖效果较好。玉米秸秆覆盖量也显著影响了4种土壤酶的活性,总体来说覆盖量越大酶活性越强。土壤脲酶、碱性磷酸酶和蔗糖酶的活性与一年中的气候变化有关,随着土壤温度的升高而提高,7月份酶活性均达到最高,而土壤过氧化氢酶与其他3种酶相比,受温度的影响相对较小,10月份酶活性最大。因此,生物覆盖显著增加了银杏用材林土壤中脲酶、碱性磷酸酶、过氧化氢酶和蔗糖酶的活性,可用于提高银杏用材林地土壤的熟化程度和肥力水平。     

季节性雪被下土壤微生物动态研究进展

在冬季,季节性雪被覆盖地区伴随着雪被的发育和消融,土壤温度、含水量和土壤冻融状态剧烈波动强烈影响着土壤微生物的动态转变及营养需求的改变,从而对高山地区冬季土壤矿质元素转化、土壤养分供应、植物分布等具有十分重要的影响。大量研究表明,高山生态系统中土壤微生物群落存在明显的季节转换现象,夏季以细菌为主,冬季则以真菌为主。在冬季,土壤微生物的生长和活性都是被可利用碳所限制的。全球变暖背景下,积雪厚度和凋落物供应的改变,必将对土壤碳供应水平产生影响,导致微生物群落的动态变化,从而对土壤中营养物质的利用和循环产生显著效应,这也是该领域新的研究方向之一。     

香樟凋落叶分解对几种园地作物抗性生理和土壤氮组分的影响

【目的】探讨香樟(Cinnamomum camphora)凋落叶添加到土壤中对小白菜(Brassica chinensis)、莴笋(Lactuca sativa)、茄子(Solanum melongena)生长和抗性生理的影响以及土壤矿质化氮的动态响应。【方法】采用盆栽试验,以单位面积香樟叶年凋落量作为凋落叶的基本添加量,设不添加凋落叶的对照(CK)和3个凋落叶添加水平,即A₁(25 g/盆)、A₂(50 g/盆)、A₃(100 g/盆),每处理重复5次,处理3种作物共计60盆。处理后,定期对植株生长指标(株高、地径)和抗性生理指标(超氧化物歧化酶、过氧化氢酶、过氧化物酶)和作物所生长土壤的硝态氮、铵态氮含量进行测定。【结果】香樟凋落叶分解对3种作物的地径、株高均有明显的抑制作用,且有随凋落叶添加量的增加而增强并随分解时间的延长而逐渐减弱的效应; 香樟凋落叶分解初期(20～40 d),各水平处理均显著地促进了叶片超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,抑制了过氧化物酶(POD)活性。凋落叶分解到80 d时,各处理CAT、POD、SOD活性的差异明显缩小; 加入不同量的香樟凋落叶在一定时间(30～50 d)内大幅降低了土壤矿化氮(硝态氮和铵态氮)含量; 不同作物对香樟凋落叶化感作用的敏感程度不同,莴笋最为敏感,其次是小白菜,茄子的耐受性最强,相对更适宜在香樟林间或林缘种植。【结论】香樟凋落叶分解可能降低了土壤氮素的有效性,并对作物造成活性氧伤害,最终限制其生长发育。     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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