千山森林典型物种燃烧特性

依据千山植被的特点,选取几种典型植物的凋落物和新鲜枝叶,采用热分析技术研究其燃烧过程特征,并进行了动力学分析。燃烧实验结果表明,各种试样在80～170℃是脱水期,在170～550℃进入剧烈燃烧反应失重阶段,并存在一个明显的放热过程,但放热量差距较大。在550℃后,所有的试样都进入缓慢氧化失重阶段。凋落物的活化能从大到小的顺序是辽东栎、油松、狗尾草、大叶朴。鲜枝叶的活化能从大到小的顺序是油松、苔草、辽东栎、大叶朴。     

子午岭森林凋落叶对土壤细菌群落结构的影响

为了深入认识森林凋落物与土壤微生物群落结构间的关系,通过小盆模拟凋落叶覆盖实验,运用PCR-DGGE技术,研究了黄土高原子午岭主要树种凋落叶覆盖对土壤细菌群落结构的影响.多样性分析结果显示,单一种类凋落叶处理后的细菌群落其Shannon-Wiener指数的变化趋势为辽东栎(3.54)油松(3.49)白桦(3.30);不同凋落叶混合处理后,细菌群落多样性增高或降低,以油松-辽东栎-白桦凋落叶混合处理的Shannon-Wiener指数最高;聚类分析结果显示,8种处理土样可分为4个类群,分别代表了凋落叶混合处理土壤(S2、S5、S3和S4),单一种类凋落叶处理土壤(S7和S8),单一种类凋落叶处理土壤(S6)和无凋落叶处理的土壤对照(S1).研究表明:凋落叶覆盖处理可使细菌群落结构发生明显改变,凋落叶单独处理和混合处理所造成的细菌群落结构的变化不同,这些变化与凋落叶种类及其交互作用方式有关.     

PVC的热失重和热解动力学

热重法对PVC树脂的热解研究表明，热解过程可分为3个阶段，250～350℃为第一失重阶段、350～400℃为稳定阶段、400～550℃为第二失重阶段；升温速率对热解有较显著的影响，随升温速率的增加，Tb、Tf和Tm随之提高，但各阶段的失重率并不改变；气氛对热解有重要的影响，在含氧气氛中总失重约为100%，而氢气中的总失重最低。热解动力学研究表明，PVC的热解为一级反应过程，3个阶段的热解活化能受气氛影响稍有差异，分别为170～200kJ／mol、10～20kJ／mol和50～80kJ／mol，各阶段活化能的较大幅度变化说明各阶段热解反应机理是不同的。     

秦岭南坡油松和锐齿栎群落凋落叶碳释放及其与分解的关系

利用野外分解袋法分别对秦岭南坡油松和锐齿栎群落内凋落叶进行了为期24个月的分解试验.研究了凋落叶C释放过程及其与凋落叶分解过程中N、P释放和C/N、C/P比值变化的关系.研究结果表明:(1)油松群落凋落层(11265.58kg/hm2)C密度显著大于锐齿栎群落凋落层C密度(3047.31kg/hm2)(P<0.01),达到了3.7倍;(2)在凋落叶分解初期,2个群落凋落叶中碳含量均呈现先增加后下降的趋势,锐齿栎凋落叶C释放速率大于油松凋落叶C释放速率(P<0.01);(3)在两种群落类型凋落叶分解过程中,碳剩余百分率随时间变化规律符合Olson分解指数模型(R>0.81);(4)凋落叶C剩余百分率与凋落叶和N、P剩余百分率之间具有显著的二项式回归关系(锐齿栎凋落叶P剩余百分率除外),与凋落叶C/N、C/P呈显著的线性相关关系.凋落叶的C释放对凋落叶分解速率、养分元素的释放以及整个森林生态系统的物质循环过程产生显著的影响.     

九寨沟不同类型森林群落凋落物分解的研究

利用网袋法对九寨沟主要森林类型的凋落物的分解作用进行了研究.结果显示,九寨沟各林型凋落物的分解率k以白桦林最高,达0.7864,巴山冷杉林最低,为0.2705.九寨沟6个主要类型群落中,除巴山冷杉林的年分解率为23.70%,与一般温带针叶林分解率相似外,其余皆在30.20%至54.45%之间,高于温带森林凋落物的平均分解速率20%～30%.在实验期内五次取样的失重率与时间的关系有两类,它们以海拔2400m为界.在海拔2400m以下的白桦林、青杆林和油松林群落中,凋落物的失重率变化呈S形;在海拔2400m以上的辽东栎林、红桦林和巴山冷杉林群落中,凋落物的失重率变化呈山字形.这6种类型森林群落凋落物的分解作用受多种因素影响.一般地,海拔相同时阔叶林群落凋落物分解比针叶林群落快.     

不同粒径城市污泥热解和燃烧动力学研究

采用德国耐驰公司STA 409pc热重分析仪,对3个不同粒径的污泥颗粒(d≤0.25mm,0.25mm0.83mm)以升温速率20℃/min在纯氮和空气气氛中进行实验,并对污泥进行了元素分析和工业分析,对金属的含量进行测定.采用MATLAB 7.11.0(R2010b)中的surface fitting tool进行平面拟合的方法计算了相关的动力学参数.结果表明,污泥的热解可以分为3个阶段:水析出阶段(100～180℃)、挥发份热解阶段(205～550℃)和部分难挥发有机物与无机物的降解阶段(550～900℃).而污泥的燃烧可以分为4个阶段:水析出阶段(100～180℃)、挥发份的燃烧阶段(180～475℃)、碳燃烧阶段(475～595℃)和无机盐分解阶段(595～900℃).不同粒径下污泥热解第2阶段活化能约为48kJ/mol,反应级数为1.5～1.8.燃烧第2阶段的活化能约为33kJ/mol,反应级数为1.1～1.8.燃烧第3阶段活化能约为176kJ/mol,反应级数为1.1～1.2.     

不同变质程度煤燃烧阶段动力学参数

为研究煤自燃特征温度及危险程度,通过热重试验确定各煤种各个阶段温度范围和特征温度值,并用Freeman-Carroll法建立了反应研究f(α),并求出燃烧阶段煤的指前因子和活化能,并对特征温度值、指前因子和活化能变化规律进行了分析.研究结果表明:6种煤样燃烧阶段温度分别为247℃~433℃、280℃~537℃、279℃~542℃、272℃~550℃、313℃~574℃和365℃~594℃;随着固定碳的增加,煤燃烧过程及特征温度点滞后,煤的活化能和指前因子增大,1#煤样最易自燃,6#煤样最不易自燃;T1温度从247℃增大到365℃,T2温度从386℃增大到479℃,T3温度从408℃增大到514℃,T4温度从433℃增大到594℃.     

灵空山油松林内凋落物与油松幼苗空间分布相关关系研究

以灵空山1 ha天然油松林为研究平台,通过野外收集器收集凋落物和室内分析实验的方法,分析灵空山油松林内凋落物物种组成、数量、空间分布等与油松幼苗空间分布的关系,揭示凋落物对油松幼苗所造成的影响,阐明凋落物不同组分之间与幼苗的空间分布关系.本研究参照拿马巴洛科罗拉多岛(Barro Colorado Island,BCI) 50 ha样地技术规范,在灵空山1 ha天然油松林长期监测样地内设置了11个种子收集器,从2014年9月到2016年12月,每15天收集掉落于收集器中的果实、种子及其相关附属物等.利用2年间收集的种子雨数据,主要结论如下:(1)收集器收集到的凋落物总重量为7.899 kg,其中叶凋落量最大,达到78.56%,收集到的凋落物树种共有10种,占样地树种数的35.7%.(2)油松幼苗在收集器周围半径10 m范围内的数量远多于半径5 m.(3)种子和果实的数量与幼苗的数量大致呈正相关,部分样地果实与幼苗呈负相关.(4)在11个凋落物收集器内,全部收集到凋落物,油松叶子存在于每个收集器中,其中的凋落物平均为682.42 g,其变异系数为0.29.(5)采用spss软件对凋落物不同的组分与幼苗进行pearson相关性分析,得出幼苗与油松叶、种子、果实有显著相关关系,凋落物中的树枝、树皮等附属物以及雄球花与幼苗空间分布无明显相关关系.     

不同落叶林林下凋落物的分解与养分归还

用分解袋法研究胡桃楸、落叶松纯林及其混交林下叶凋落物的分解及养分归还速率。结果表明：在1个生长季内，3种林分叶凋落物分解速率从大到小依次为：胡桃楸纯林、混交林、落叶松纯林。胡桃楸纯林叶凋落物归还氮的速率最快，落叶松纯林叶凋落物归还磷、钾的速率最快。二组成混交林后，混交林叶凋落物归还氮的速率较落叶松纯林明显提高，而归还磷、钾的速率较胡桃楸纯林明显提高。胡桃楸与落叶松混交后叶凋落物养分归还速率较其各自纯林的有所提高，可能是混交林增产机理之一。     

干旱对4种木本植物幼苗脯氨酸含量的影响

为探讨同一植物群落内不同生长型（乔木和灌木）的植物幼苗对土壤干旱反应的差异,采用室内盆栽法,测定了干旱条件下辽东栎、大叶白蜡、柔毛绣线菊和二色胡枝子4种木本植物幼苗中脯氨酸的含量。结果表明,脯氨酸含量的变化老叶中大于幼叶,根中脯氨酸增加的幅度比茎叶中都大。辽东栎和大叶白蜡根、茎、叶的脯氨酸增加幅度大于柔毛绣线菊和二色胡枝子的增幅。根据脯氨酸和土壤含水量的变化差异,可以得出4种植物的抗旱性强弱依次为：辽东栎,大叶白蜡,柔毛绣线菊,二色胡枝子。     

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