内生真菌感染对宿主植物羽茅锌耐受性的影响

以感染和未感染内生真菌的羽茅(Achnatherum sibiricum(L.)Keng)为实验材料,在营养液中加入ZnSO4进行锌胁迫实验,分析内生真菌对宿主植物锌耐受性的影响.在胁迫期间,内生真菌感染对羽茅净光合速率的变化没有显著影响,但是降低了其宿主的PSⅡ光化学效率(Fv/Fm).与未感染内生真菌的植株相比,内生真菌感染对羽茅的总生物量没有显著影响,但增加了植株分蘖数和叶片延伸生长累积值.同时内生真菌感染还降低了羽茅植株整体和地上部的Zn2+含量.总体来看,内生真菌感染改善了宿主羽茅的锌耐受性.     

不同CO_2浓度和氮素处理下内生真菌感染对高羊茅的生理生态影响

以感染内生真菌的人工禾草高羊茅为研究对象,通过比较不同CO2浓度和氮素处理下,感染内生真菌和不染菌植物在种子萌发和营养生长等方面的差异,探讨感染内生真菌的高羊茅对CO2升高的响应.试验结果表明,(1)内生真菌感染影响了宿主种子萌发对CO2浓度升高的响应,CO2浓度升高使得内生真菌感染促进了宿主植株的胚芽和胚根的伸长;(2)CO2浓度升高使高羊茅地下生物量显著增加,只是内生真菌感染植株的地下生物量显著低于不染菌植株;CO2浓度升高使不染菌植株地上部分氮含量显著降低,而对染菌植物无显著影响;(3)内生真菌对宿主响应CO2的影响与氮素供应水平有关,在高浓度CO2和氮素供应下内生真菌感染显著降低了宿主植物的分蘖数,而在高浓度CO2和缺氮供应下,染菌植株的可溶性糖含量显著高于不染菌植株;(4)内生真菌对宿主响应CO2的影响与氮素供应形态有关,在高浓度CO2和硝态氮供应下,内生真菌感染显著降低了宿主植物的地上生物量,而在铵态氮供应下,染菌植株的总游离氨基酸含量显著高于不染菌植株.     

不同种群羊草幼苗对土壤干旱胁迫的生理生态响应

对干旱条件下三个不同种群羊草叶水势、生物量及其分配格局、生理生化反应进行研究．各种群羊草的生长对轻度干旱胁迫不敏感，重度胁迫下羊草生物量均呈下降趋势，但不同种群变化存在差异．重度胁迫下白音锡勒种群生物量显低于对照和轻度胁迫，而达里湖种群和嘎松山种群与对照、轻度胁迫差异不显．随胁迫强度加大，达里湖种群和嗄松山种群地下部分投入比例增加，白音锡勒种群重度胁迫下地下生物量却显减少．三个种群羊草叶水势变化相似，均随胁迫时间的延长和胁迫强度的加大而下降，但轻度胁迫与对照差异不显，重度胁迫处理第6d迅速下降，第8d降到最低，复水后不同种群羊草水势恢复程度不同．三个种群羊草叶片可溶性蛋白含量、可溶性糖含量、游离脯氨酸含量、MDA含量的变化相似，均随干旱胁迫的加剧而增加，复水后逐渐恢复．嘎松山和白音锡勒种群可溶性糖和脯氨酸含量增加的幅度大于达里湖种群，胁迫条件下达里湖种群羊草叶片的MDA含量高于其它两个种群．     

一株内生真菌对铅胁迫下黑麦草幼苗生理特性的影响

采用盆栽实验研究了内生真菌对铅胁迫下黑麦草幼苗生理特性的影响。结果表明,铅胁迫对黑麦草幼苗的生长有抑制作用,而经过灌溉不同浓度(稀释10倍、20倍、30倍)内生菌菌液的处理后,可以增加黑麦草的叶绿素含量、过氧化物酶活性和平均苗高,降低黑麦草幼苗的相对电导率和丙二醛含量,并且发现灌溉浓度为稀释20倍的菌液时效果最显著。研究表明,内生真菌可以提高黑麦草幼苗抵抗铅胁迫的能力。     

水分预胁迫对干旱条件下高羊茅光合特性的影响

采用土培的方法,通过对高羊矛幼苗进行水分预胁迫、解除胁迫、再胁迫处理,研究了水分预胁迫对干旱条件下高羊茅光合特性的影响.结果表明,经水分预胁迫的高羊茅能够更好地利用有限的水分,光合速率、气孔导度、胞间二氧化碳浓度、蒸腾速率下降幅度均低于未经预胁迫的高羊茅,水分预胁迫缓解了干旱对高羊茅光合特性的影响.     

丛枝菌根真菌对植被混凝土中黄花决明生长和抗旱性的影响

干旱胁迫是植被混凝土技术在干旱半干旱地区进行生态修复的最大障碍之一.本研究采用盆栽试验法,探究干旱胁迫下接种摩西斗管囊霉(FM)和根内根孢囊霉(RI)对植被混凝土中黄花决明生长、抗旱性的影响.试验设置为双因素(3种水分×3种接种处理)完全随机试验.结果表明：相同干旱胁迫下,与对照组相比接种AMF能减缓干旱对黄花决明根长和总生物量的抑制作用,但会降低黄花决明的株高.接种AMF显著提高干旱胁迫下超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,同时降低丙二醛(MDA)含量,其中RI对上述指标的的作用效果显著高于FM.干旱胁迫导致可溶性糖(SS)和脯氨酸(Pro)含量显著升高,可溶性蛋白(SP)含量显著降低.接种AMF对提高干旱胁迫下SS和SP含量效果显著,但显著降低Pro含量.通过主成分分析法对不同处理下黄花决明抗旱性进行综合评价发现,接种AMF能有效提高黄花决明抗旱性,其中接种RI对于提高植被混凝土中黄花决明抗旱性的作用优于FM.     

干旱胁迫对红皮柳光合特性日变化及生长的影响

红皮柳(Salix purpurea)是我国西北地区重要的乡土树种,生长快、适应性强,在水土保持、防护林和生物质能源等方面发挥重要作用。以红皮柳扦插苗为研究材料,通过盆栽试验,在4种不同程度干旱胁迫处理(对照、轻度干旱、中度干旱和重度干旱胁迫)下,测定叶片的光合作用参数及生长量,分析探讨干旱胁迫对红皮柳光合特性及生长的影响。结果表明:在轻度、中度和重度干旱胁迫下,红皮柳叶片净光合速率(P_n)日均值分别比对照下降10.4%(P＞0.05)、17.9%(P＜0.05)和58.2%(P＜0.05),中度和重度干旱胁迫下P_n下降量达到显著水平; 随着干旱胁迫程度的加剧,P_n的下降伴随着蒸腾速率(T_r)和气孔导度(G_s)的显著下降,水分利用效率(E_WUE)逐渐升高,胞间CO₂浓度(C_i)先下降后上升; 轻度干旱胁迫和中度干旱胁迫下P_n的降低是由于气孔限制引起,而重度干旱胁迫下受到气孔因素与非气孔因素的共同作用。而且,红皮柳生长受到干旱胁迫的显著影响,随着干旱胁迫程度的加重,株高和基径的相对增长率下降程度增大。     

不同种群羊草幼苗对渗透胁迫的反应和生理生态适应

用聚乙二醇(PEG 6000)对内蒙古不同生境3个羊草种群(阿巴嘎、白音锡勒、嘎松山)进行渗透胁迫(-0．5Mpa，-1．0Mpa)．结果表明：各种群羊草对轻度胁迫(-0．5Mpa)反应不敏感，叶片含水量和膜透性与对照差异不显；随胁迫强度增大和胁迫时间的延长，叶片相对含水量、根系活力、叶片生长速率均有不同程度的下降；相反，膜透性增大，脯氨酸大量积累，根冠比增大；脯氨酸积累、质膜相对透性与叶片含水量呈显负相关(r＝-0．716l，r＝-0．8212)．不同地理种群羊草对渗透胁迫在时间和强度上的反应具有一定差异．阿巴嘎种群膜伤害程度较小、叶片含水量变化缓慢、脯氨酸积累量小、根冠比增大更显、维持较高根活力和叶片生长量，其抗旱性强于其它两个种群．白音锡勒种群和嘎松山种群对渗透胁迫的反应相近．     

多花胡枝子对干旱胁迫的生理响应初步研究

实验采用聚乙二醇6000(PEG6000)在室内模拟干旱条件,研究不同程度干旱胁迫对多花胡枝子相对含水量、相对电导率、丙二醛(MDA)、叶绿素含量、超氧化物歧化酶(SOD)活力和脯氨酸含量的影响,旨在探求其在沙质条件下的生存能力.结果表明:随着干旱胁迫的加强,电导率和丙二醛(MDA)明显增加,而叶绿素含量、超氧化物歧化酶(SOD)活性和叶片相对含水量均呈显著下降趋势.以30%PEG6000处理对多花胡枝子的伤害最大.在胁迫处理12h,30%浓度处理的植株电导率高至(50.7%)比对照组高13.4%;SOD活性最低为100.4 U/g;在胁迫处理24h时,10%浓度处理的植株脯氨酸含量高达1 024 Ug/g,此后逐渐降低;在处理48h时,30%浓度处理的植株MDA含量为17.58 nmol/g,高于其他胁迫处理.在PEG6000处理过程中,处理0~12h为植株的抗性阶段,处理12~48h为植株的耗尽阶段.可见,在干旱胁迫下,多花胡枝子可以通过改变体内物质含量来提高抗性,渡过逆境.     

爆发型种群铜锤草的生态适应机制初探

入侵成功的外来种铜锤草(Oxalis corymbosa)表现出爆发型的分布格局.为探索该物种对异域环境的适应性,以实验手段对不同人工胁迫环境下一个生长季的铜锤草生活史特征进行了比较.结果表明:水分胁迫促使植株株型紧缩,叶片周转率提高,生物质量累积下降;遮阴条件显著降低叶的周转率(P<0.001),生物质量累积下降;竞争条件下植株株型高大,生物质量累积增加显著(P<0.001),表现出形态可塑性.水分胁迫下植株生长缓慢,增长期缩短,最大生长量显著降低(P<0.001);遮阴条件下增长期缩短,叶面生长速度提高,而高生长速度有所下降;竞争促进生长,生长期和生长速度均有明显提高.相对而言,水分胁迫下种群存活率提高,无性繁殖率降低,且水分胁迫越严重无性繁殖率越低;遮阴促使种群快速完成生活史,种群存活率和无性繁殖率均降低;竞争条件下存活率有所下降而无性繁殖率增加,种群存活和繁殖之间的颉抗关系表现明显.胁迫环境下,种群适合度有所不同.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-