外源Ca^2＋对水稻幼苗生长的影响

用不同浓度外源Ｃａ＾２＋对水稻种子进行处理,探讨钙对水稻幼苗生长的影响,结果表明：低浓度（０．２５－０．５ｍｍｏｌ．Ｌ＾－１）Ｃａ＾２＋处理的水稻幼苗干物质及健壮度均高于对照,其中以０．５ｍｍｏｌ．Ｌ＾－１Ｃａ＾２＋处理效果最显著,水稻幼苗干物重及健壮度分别比对照高９．７％和８％;０．２５ｍｍｏｌ．Ｌ＾－１Ｃａ＾２＋处理的叶绿素含量均略高于对照,加钙处理水稻幼苗根系活力高于对照,过氧化氢酶活性也高     

外源Ca~(2 )对水稻幼苗生长的影响

用不同浓度外源Ｃａ２＋ 对水稻种子进行处理,探讨钙对水稻幼苗生长的影响． 结果表明：低浓度（０．２５～０．５ ｍ ｍ ｏｌ·Ｌ－ １）Ｃａ２＋ 处理的水稻幼苗干物质重及健壮度均高于对照,其中以０．５ ｍ ｍ ｏｌ·Ｌ－ １ Ｃａ２＋ 处理效果最显著,水稻幼苗干物重及健壮度分别比对照高９．７％ 和８％ ;０．２５ ｍ ｍ ｏｌ·Ｌ－ １Ｃａ２＋ 处理的叶绿素含量均略高于对照;加钙处理水稻幼苗根系活力高于对照,过氧化氢酶活性也高于对照．     

离子液体1-己基-3-甲基咪唑溴化盐对番茄种子萌发及幼苗生长的影响

用不同质量浓度(0、3、6、9、12、15mg·L-1)的离子液体1-己基-3-甲基咪唑溴化盐([C6mim]Br)水溶液对番茄金顶一号品种进行浸种和苗期水培,研究了种子萌发、幼苗形态以及幼苗叶片生理生化的变化.结果表明,当离子液体质量浓度9mg·L-1时,种子发芽率比对照降低差异显著;当离子液体质量浓度6mg·L-1时,根长和苗长比对照降低差异极显著.本研究所设的所有离子液体质量浓度均使番茄幼苗叶片中叶绿素含量比对照降低差异显著,尤其是当9mg·L-1时则差异极显著.幼苗叶片超氧化物歧化酶(SOD)在离子液体质量浓度为6~12mg·L-1和15mg·L-1时分别比对照降低达显著与极显著水平,当离子液体质量浓度12mg·L-1时,POD活力比对照降低差异极显著.处理组幼苗叶片中超氧阴离子(O2·-)产生速率和丙二醛(MDA)含量分别在离子液体质量浓度6mg·L-1和9mg·L-1时比对照增加,达极显著差异水平.在本试验条件下,离子液体1-己基-3-甲基咪唑溴化盐对番茄种子萌发和幼苗生长均具有明显的抑制效应.     

山核桃果皮黄酮提取液对四种作物苗期光合性能的影响

采用6种浓度山核桃果皮黄酮提取液（0.1～2.0mg·L^-1）处理盆栽小麦、玉米、大豆和绿豆幼苗,研究对苗期叶片光合速率、气孔导度、蒸腾速率、细胞间隙CO2等光合性能的影响.结果显示：在试验浓度范围内,黄酮提取液对四种作物苗期的光合性能具有低浓度促进、高浓度抑制影响;0.1、0.5mg·L^-1黄酮提取液提高了叶绿素a、叶绿素b和叶绿素总量,促进光合速率、气孔导度、蒸腾速率,适当增加细胞间隙内部的CO2浓度,以0.1mg·L^-1处理效果最明显,与对照相比,四种作物的叶绿素总量和光合速率最高增加了20.9%和21%,处理的影响达显著或极显著水平（（P〈0.05或P〈0.01）;超过0.5mg·L^-1叶绿素含量、光合速率、气孔导度、蒸腾速率逐渐降低,细胞间隙的CO2浓度快速增加.研究表明,适宜浓度的山核桃黄酮提取液具有提高叶片叶绿素含量,促进气孔开放度,增加对细胞内的CO2供应,改善叶片光合性能的作用.     

尿素和硼及生长调节剂对荔枝花粉萌发与生长的影响

25度条件下,在荔枝花粉萌发培养基上添加0．1％－0．4％的尿素,0．1－1．5％的硼酸及0．1－1．0mg.L^-1的萘乙酸均不同程度地促进花粉萌发与花粉管生,5－50mg.L^-1乙烯对花粉的萌发与花粉管生长则有抑制作用,抑制程度与其浓度呈正相关,在1－5mg.L^-1的BA下,花粉萌发率下降,但花粉管生长受促,25mg.L^-1BA可显著抑制花粉的萌花与生长,三个荔枝品种花粉萌发对温度较敏感,18度时不萌发。     

林业废弃物山核桃果皮黄酮对作物苗期营养吸收的影响

以盆栽小麦、玉米、大豆和绿豆幼苗为材料,研究了6个浓度山核桃黄酮提取液（0.1～2.0 mg·L ^－1）处理对四种作物幼苗新生根系的电导率、根系活力、硝酸还原酶活性、营养元素吸收、生物量的影响．结果显示：0.1～0.5 mg·L ^－1黄酮提取液对四种作物的苗期营养生长具有良好的促进效应,小麦和绿豆的根系活力分别为0.29、0.35ug ．dg ^－1．h^－1,比对照提高40％～24％,大豆和玉米的硝酸还原酶活性分别是49.9、53.1mg ．L ^－1,比对照增加54％～24％,处理对四种作物的影响达极显著或显著水平（ P＜0.01,P＜0.05）;适宜浓度的黄酮提取液能显著增加幼苗的鲜重与干重;促进根系对N、K、Ca、M g、Fe、M n、Cu和Zn的吸收,但对四种作物促进效应的浓度各有差异．研究表明：适宜浓度的山核桃黄酮提取液具有促进四种作物苗期生长、改善幼苗新生根系对矿质营养吸收的作用．     

外源一氧化氮对铬胁迫下小麦幼苗生理的影响

研究了在40 mg·L^-1Cr6＋胁迫下,0.1 mmol·L^-1～1.0 mmol·L^-1外源NO供体硝普钠（SNP）处理对小麦幼苗生长、叶绿素含量、丙二醛含量、相对电导率、叶片保护酶（SOD、POD和CAT）活性和可溶性糖含量的影响.结果表明,NO缓解小麦幼苗Cr6＋胁迫具有剂量效应,以0.4 mmol·L^-1SNP的效果最好.     

BN系列生长调节剂在油菜上的应用效果初报

研究结果表明：在油菜的抽薹期和初花期以清水为对照，分别喷洒BN－1型浓度为4mg/kg,6mg/kg,8mg/kg和BN－2型浓度为2mg/kg,4mg/kg,6mg/kg的生长调节剂均能使油菜角果变宽，表面积增加，光合面积增大，促进了光合产物的形成 和积累，对籽粒浆增生起到了重要作用，油菜单株产量显著提高，在油菜抽薹期以BN－1型浓度为8mg/kg的效果良好，初花期则以BN－1型6mg/kg的效果最好，另外BN－1型浓度6mg/kg的处理对油菜抽薹速度有显著的促进作用，BN－2型4mg/kg次之。     

磷素水平对水稻幼苗生长发育的影响

以4种不同基因型水稻为材料,研究磷素水平对水稻幼苗的生物学和营养学性状的影响.结果表明:低磷处理对水稻幼苗各生物学性状影响很大,低磷条件下水稻幼苗株高、鲜重、干重均低于对照处理,根长伸长,根冠比增大;供磷过量处理水稻幼苗株高和干重低于对照.四种水稻幼苗相比,高优35的磷素利用效率明显低于其它三个品种.     

赤霉素对蓝莓种子发芽影响的研究

本文主要研究了不同浓度的赤霉素（GA3）对蓝莓（Vaccinium corymbosum）种子萌发的影响,并采用发芽率、发芽势对蓝莓种子发芽效果进行了评价.结果表明：蓝莓种子萌发浓度幅较宽,在浓度50～300 mg·L^-1范围内均能萌发,种子的发芽率和发芽势在不同浓度下变化显著;在50mg·L^-1条件下,种子的发芽率和发芽势最高;因此,蓝莓种子最佳萌发浓度为50 mg·L^-1;发芽率和发芽势在浓度为50 mg·L^-1时,分别可达16％、16％。     

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.     

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.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

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。