台湾桤木与黑麦草复合模式细根和草根的 分解及养分动态

采用网袋法对台湾桤木与黑麦草复合模式下的细根和草根分解及养分释放进行了为期1年的研究。结果表明：直径0~1 mm、1~2 mm、0~2 mm台湾桤木细根、黑麦草草根、混合根(台湾桤木0~2 mm细根与草根质量比1∶1混合)的干质量残留率分别为39.47%、32.23%、37.11%、16.93%、24.05%,应用Olson指数方程模拟细根和草根的分解过程,拟合程度较好(p<0.01)。分解初期细根N、P、Ca的浓度存在上升趋势,K浓度则明显下降,Mg浓度变化平稳,草根和混合根N、K浓度变化趋势与细根的相同,其余的养分浓度与细根的浓度表现出不同规律。细根和草根分解过程中K、Mg、P的残留率与其干质量残留率变化相似,而N、Ca的残留率下降则较平缓;元素释放速率以K最快,其次为Mg、P、N,Ca最慢。混合处理的分解速率和N、P、K、Ca释放率介于单独分解的0~2 mm细根和草根相应释放率之间,而Mg释放率则大于单独分解的0~2 mm细根和草根的释放率。     

混交林杉木观光木细根分解过程能量变化

对福建三明杉木观光木混交林中杉木和观光木细根分解过程中干质量热值、能量残留率、能量年归还量及释放量进行了系统的研究,结果表明,细根在分解过程中干质量热值呈递减趋势变化.同一树种细根径级越小其能量残留率也越小.杉木细根的年能量归还量为2.8184×106J.m-2,观光木细根的能量年归还量为0.6435×106J.m-2,在不同径级细根能量年归还量组成中,两个树种的<0.5 mm径级细根的能量年归还量均占60%以上,表明在细根的能量流动中,<0.5 mm细根起着重要的作用.杉木细根的能量年释放量为1.8187×106J.m-2,观光木细根的能量年释放量为0.5864×106J.m-2.     

海南岛北部海岸木麻黄防护林凋落物量及养分归还动态

在固定样地采用凋落物收集器收集并定期回收凋落物的方法,研究了海南岛北部海岸木麻黄防护林2008—2009年的凋落物产量及N、P、K养分归还动态. 结果表明:（1）木麻黄林年凋落物量为5.9844t/hm2,其中小枝凋落物量在年凋落量中占有最大比例,为88.99%;其次是杂物,为6.63%;最小是皮+枝,为4.38%. 木麻黄林总凋落物量和小枝凋落物量的月变化格局十分相似,皮+枝、杂物凋落物量月动态变化则比较平缓.（2）小枝中N、P、K 3种主要养分年归还总量为94.69kg/hm2,其中N归还量在年归还量中占有最大比例,为78.86%;其次是K,为18.71%;最小是P,为2.43%. N归还量月动态与总凋落物量月动态变化极其相似,P、K归还量月动态则比较平缓.     

川南毛竹林生态系统养分动态分析

以目标产量和现实产量为基础,分别计算了川南毛竹林生态系统中N、P、K、Ca、Mg、Si等养分年亏 损量。结果显示：(1)当年采伐量为22.5 t/hm2时,6种元素的养分输出总量为216.78 kg/hm2,其中N为 93.13 kg/hm2、Si为57.61 kg/hm2、K为38.04 kg/hm2、Ca为11.39 kg/hm2、Mg为8.33 kg/hm2,P为8.28 kg/hm2,采伐时若将竹叶归还林地,养分年总输出量将减少73.3 kg/hm2;(2)在现有的经营强度下(即年均 采伐产量为9.0 t/hm2)时,6种养分亏损总量为：7.96 kg/hm2,各元素亏损率的排序为：Si(29.91 %)、P (27.19 %)、N(22.97 %)、Mg(8.51 %)、K(7.60 %);(3)结合各养分在土壤中贮量及其亏损状况分析表明, 川南毛竹林地施用P肥对提高毛竹产量的效果最直接,但补充K、Si、Mg等养分是防止毛竹林地力衰退、维 持毛竹林经营可持续性的必要措施和手段。     

福建柏和杉木人工林细根N、P养分含量动态

研究细根养分含量的4种动态：（1）福建柏和杉木人工林细根N、P含量的差异；（2）细根N、P含量与细根直径的关系；（3）在细根衰老过程中是否发生N、P的转移；（4）细根N、P含量是否有季节性的变化．从1999年1-12月隔月应用连续根钻法对福建三明莘口林场福建柏和杉木人工林细根进行取样并测定活、死细根的N、P养分含量．结果表明：福建柏人工林细根的N、P含量均比杉木人工林略大，且两者的N、P含量均随细根径级的减小而增加；各径级死细根的N、P含量均略低于相应的活细根，说明细根在衰老过程中发生了养分的转移但迁移量很小；福建柏各径级细根N、P含量的动态变化表现为单峰型，在9月最高；杉木各径级细根N、P含量的动态变化亦表现为单峰型，N含量高峰出现在9月，而P含量则在9月或11月最高．     

神农架巴山冷杉林凋落物量养分归还及分解特征

【目的】掌握森林凋落物产量及组成的动态变化、凋落物养分归还量及凋落物分解特征,了解凋落物在森林生态系统养分循环中的作用。【方法】选择神农架巴山冷杉天然林和人工林,在样地内布置凋落物收集框和凋落物分解袋,通过1 a的连续观测,比较天然林和人工林凋落物产量及分解速率的差异。【结果】巴山冷杉天然林和人工林年凋落物总量分别为6 217.44和4 833.46 kg/hm²,天然林比人工林年凋落物总量高28.63%。凋落物中以落叶为主,天然林和人工林落叶产量分别占凋落物总量的55.24%和54.76%; 其次是落枝,分别占总量的22.18%和19.66%; 树皮及花果等其他组分含量相对较少,分别占总量的22.58%和25.58%。巴山冷杉林凋落模式为双峰型,分别在10月和次年6月具有明显高峰期,而在次年2月凋落量最小。天然林和人工林凋落物养分年归还量分别为77.84和54.47 kg/hm²,天然林比人工林凋落物年养分归还量高42.91%,5种大量元素年归还量大小顺序均为N＞K＞Ca＞P＞Mg。凋落物在初始阶段分解较快,天然林和人工林凋落物在最初2个月失重率分别达18.70%和11.35%。天然林和人工林凋落物分解常数分别为0.303和0.241,凋落物半衰期分别为1.70 a和2.57 a,而凋落物周转期分别为9.30 a和12.12 a。【结论】神农架巴山冷杉林凋落物产量较高,分解速率较慢,天然林凋落物对土壤的改良效果更好。     

华北落叶松人工林营养元素的生物循环

对秦岭南坡 2 3年生的华北落叶松人工林包括 0～ 60cm土层中N、P、K、Ca、Mg 5种大量营养元素的含量进行了测定 ,其总贮量达到 1 .38× 1 0 5kg hm2 ,土壤、乔木、灌木、草本和凋落物各层营养元素现存量分别为 1 .37× 1 0 5、837.85、1 71 .1 7、42 .86、348.90kg hm2 。各营养元素的积累量均为土壤库 >>植被 >枯落物层。在植被层中该林分营养元素的年吸收量、年存留量、年归还量分别为 92 .2 9、61 .93、30 .36kg (hm2 ·a)。N、P、K、Ca和Mg 5种元素的循环速率分别为 0 .82 5、0 .70 4、0 .5 0 1、0 .60 2、0 .689。与同一区域年龄相近的锐齿栎、油松、华山松林分的生物循环特征相比 ,华北落叶松人工林对土壤没有明显的不良影响。     

不同林龄油松针叶凋落物初期分解特性比较

应用凋落袋法,研究了北京山区24、32、40年生油松(Pinus tabulaeformis)人工林针叶凋落物初始化学组成、分解速率以及养分释放过程。结果表明:凋落物初始基质无机养分含量、灰分、粗蛋白、C/N在3个林龄之间差异性明显(p<0.05)。凋落物失重率季节动态变化表现为双峰型,且季节变化明显。随着林龄的增大,针叶凋落物年平均分解速率、分解系数k值逐渐增大。通过重复测量设计的方差分析可知,随着分解时间的延长,失重率、N剩余百分率在不同林龄间均有显著性差异,而P、K、Ca、Mg元素的积累释放受林龄影响不明显(p<0.05)。     

不同毛竹纯林枯落物养分含量和贮量的比较

运用定位研究法采集位于浙江富阳路西林区垦复与未垦复毛竹(Phyllostachys edulis)纯林枯落物样品(2002~2003年),对其枯落物的量进行比较。结果表明:不论夏季或冬季,未垦复毛竹林枯落物烘干重量均显著高于垦复毛竹林,未垦复毛竹林冬季枯落物烘干重量是垦复毛竹林的1.65~5.74倍。不同毛竹林枯落物养分呈现相似的变化特征,即垦复毛竹林枯落物养分含量和贮量由高到低序列为:Ca、K、Mg、N、P,养分含量0.16~3.3 g/kg,养分贮量0.20~4.50 kg/hm2;未垦复毛竹林相应序列是Ca、K、N、Mg、P,养分含量0.20~5.10 g/kg,养分贮量0.70~29.10 kg/hm2。毛竹林垦复之后由于林地表层的枯落物数量大为减少,枯落物养分贮量也显著低于未垦复毛竹林,因而制约潜在肥力的稳定提高,进行土壤管理时应引起注意。     

苏北杨树人工林细根生产力与周转

采用连续钻取土芯法对苏北两种模式(网格模式PW、网格台田模式PT)下4年生杨树(Populus deltoides cv. 35.)人工林细根(≤5 mm)进行研究,并采用不同估算方法对细根年净生产量、死亡量、分解量和周转率进行比较。结果表明,细根现存生物量为1.26~1.86 t/hm2。PW和PT两种模式下,细根年净生产量、死亡量、分解量和周转率分别为2.24 t/hm2、2.34 t/hm2、1.88 t/hm2、1.43次/a和1.43 t/hm2、1.29 t/hm2、1.37 t/hm2、1.31次/a,与决策矩阵法相比,采用最大最小值法平均低估了19%的细根年净生产量、68%的年死亡量、89%的年分解量和23%的周转率;土壤养分和季节水分动态是PW和PT模式细根生产量和周转率存在差异的主要原因。     

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