不同相思根瘤菌株接种厚荚相思幼苗效应的比较

从不同立地条件的6种相思林中采集根瘤并分离14株根瘤菌,将其接种到厚荚相思幼苗。结果表明,从广西本地分离的土根瘤菌比对照菌株L1(从中国林科院引进的外来优良菌种)有更好的共生效应。从综合效应看,多数菌株接种的厚荚相思幼苗与对照相比,其苗高生长量增加4．5％～18．6％,地径生长量增加2．5％～46．8％,固氮酶活性提高7．6％～241．8％,叶绿素含量提高11．0％～19．1％,叶片硝酸还原酶活性提高3．3％～34．4％,叶片含氮量提高7．4％～43．8％,叶片含磷量提高9．1％～72．7％,叶片含钾量提高8．39／6,叶片合钙量提高7．3％～41．5％,叶片含镁量提高12．5％～25．0％,叶片含铁量提高10％以上。     

豌豆根瘤菌RND外排转运基因tpaA的功能研究

Rhizobium. leguminosarum 3841 tpa A基因编码RND家族内膜外排转运蛋白,RND外排泵的过量表达是革兰阴性菌细菌抗生素耐药性形成的重要原因之一.采用基因同源重组构建豌豆根瘤菌tpa A基因突变株RLtpa A,并研究了该基因突变对根瘤菌生长、抗生素耐药性以及共生固氮的影响.结果表明,tpa A基因突变会使根瘤菌在AMS基本培养基生长延迟,但不影响其在TY天然培养基中的正常生长. tpa A基因突变可能抑制了根瘤菌中的RND家族外排泵的过量表达,从而使其抗生素耐药性降低.接种了tpa A基因突变株的豌豆植株能形成红色有效根瘤,但其接种根瘤固氮酶活性降低.实时荧光定量RT-PCR分析表明tpa A基因在根瘤类菌体中的表达显著上调.     

绿豆根瘤菌形态研究

本文对12个品种绿豆根瘤进行采集、培养，并通过染色对根瘤情况及根瘤菌形态学进行研究，结果表明：①12个品种中V3476、博绿2号外形为卵圆形，其余均为椭圆形；②根瘤着生部位除绿洲1号、95515只着生在侧根外其余品种的主根、侧根均着生根瘤；③不同品种的绿豆根瘤在同一生长时期的根瘤在大小和结瘤率上明显不同，根瘤生长最大的品种是长荚绿豆，根瘤直径为2．76～6．84mm，根瘤最小的为维绿1号，直径为1．2～3．32mm，结瘤率最高的为河北明绿、长莫绿豆、中绿1号、秦豆6、达90％，维绿1号结瘤率最低，仅为20％；④在甘露醇-酵母汁培养基上生长的孤立菌落只有长荚绿豆、秦豆6的菌落形态型为R，其余均为S；⑤培养72小时，菌落大小各有相同，生长最快的为长荚绿豆，直径达9．1mm，生长最慢的为南绿1号，直径为6．6mm；⑥绿豆根瘤菌为短杆状、长椭圆形．     

OsmC基因在豌豆根瘤菌抗氧化和共生中的功能

为研究OsmC基因在豌豆根瘤菌抗氧化和共生固氮中的功能,以豌豆根瘤菌RL3841的OsmC基因为研究对象,通过同源重组获得了OsmC基因突变株RLOsmC.结果表明:OsmC基因突变不影响豌豆根瘤菌的自生生长能力,但对无机氧化物H_2O_2和低浓度有机氧化物氢过氧化枯烯(CuOOH)都十分敏感.突变株RLOsmC感染豌豆宿主能形成红色有效根瘤,但是其固氮酶活降低了18.3%.OsmC基因的表达不受H_2O_2的诱导,但在7 d根瘤类菌体中表达量显著上调.表明根瘤菌OsmC基因在共生和抗氧化功能中发挥了重要的作用.     

用~(15)N 示踪法测定2,4-D 诱发的小麦和向日葵根瘤的固氮活性

用~(15)N 示踪法定性测定了经2,4-D 诱发的、接种豇豆根瘤菌(R.sp),菜豆根瘤茵(R.phaseoli)等四种根瘤菌和圆褐固氮菌(Az.chroococcum)的小麦(Triticum aesticum)和向日葵(Helianthus annuus)根瘤,结果表明具有固氮活性。     

T0501010 生物固氮技术在药用植物甘草种植中的应用

为了有效改善人工种植甘草的品质，提高种植效益，该项目在甘草人工种植中大面积引入根瘤菌生物固氮技术。通过人工接种根瘤菌剂，提高根瘤的生长和固氮能力，促进甘草的生长发育。接菌示范表明，接种组比对照组所结根瘤率提高，单株根瘤数增多，个体增大，接种根瘤对甘草地上、地下部分的生长均有明显的促进作用。经田间调查显示，接种甘草较未接种甘草根部直径增粗5倍之多，     

大豆和花生根瘤菌氢酶的研究

根瘤菌在共生固氮过程中因放H2所消耗的能量约占固所氮总能量的40%-6%。吸氢酶则能回收和利用固氮过程所放的H2,养活能量损失,从而提高共生固氮效率。在厌氧条件下,加入防止酶蛋白聚合的试剂,利用DEAE-纤维素和Sephacry S-200柱层析,从自养性大豆根瘤菌和花生根瘤菌类菌体中分离并提纯膜结合态氢酶。纯化的两种氢酶表现相近的分子特征：均含有大（60kD,65kD)、小（30kD,35kD)两个亚基,均为NiFe-氢酶,并且有较高的吸H2活性。大豆根瘤菌氢酶的纯酶组分不含Cyt b599。花生根瘤菌L8-3菌株能进行化能自养生长,诱导出高吸H2活性。根瘤菌的吸H2能明显提高固氮活性。从具有高吸H2活性的花生根瘤菌中分离并克隆吸氢基因,采用PCR和探针杂交技术,获得含有吸氢基因的质粒pZ-55。利用多种限制性内切酶构建了质粒pZ-55的物理图谱。通过三亲本杂交,将含吸氢基因的重组质粒转移到不吸H2的花生和毛豆根瘤菌中,所获得的结合株在自生和共生条件下均表达吸H2活性。以结合株接种大田花生,获得的共生根瘤的吸H2活性比接种受体株提高4倍,花生叶片和种子的含N量、产量分别提高1.7%、8.9%和9.6%。     

酸性红壤中热研2号柱花草高效固氮根瘤菌的筛选

为筛选酸性红壤中适合热研2号柱花草的高效固氮根瘤菌菌株,在土培中将19个根瘤菌菌株分别接种到热研2号柱花草,通过株高、茎叶干重、茎叶氮含量、茎叶磷含量等指标确定酸性红壤中接种不同根瘤菌对柱花草的影响,并通过主成分分析确定酸性红壤中与热研2号柱花草搭配的高效根瘤菌菌株.结果表明：酸性红壤中与热研2号柱花草匹配的高效菌株为RJS9-1、BS2-2、 ZJ2-2、FS3-1-1、RJS9-2及BS1-1;接种后不利于柱花草生长的菌株为LY1、NN1-1-2及SM5-1.本实验结果为实际生产中通过接种氮高效根瘤菌提高柱花草产量提供了一定参考.     

豌豆根瘤菌gshR基因的抗氧化和共生固氮作用

目的: 研究豌豆根瘤菌 RL3841 的谷胱甘肽还原酶编码基因 gshR 的功能．方法: 采用基因同源重组构建了豌豆根瘤菌 gshR 基因突变株 RLgshR,探讨了基因突变对根瘤菌抗氧化和共生固氮的影响, 利用实时荧光定量 RT-PCR检测 gshR基因的 mRNA 表达水平．结果: gshR基因缺失不影响菌株在 AMS 基础培养基中的生长能力, 但突变株对氢过氧化枯( CuOOH) 和较高浓度的 H₂O₂氧化物敏感．结论: gshR 基因突变株 RLgshR 形成正常固氮根瘤, gshR 基因的表达不受 H2O2和共生环境诱导．     

接种方式对花榈木幼苗结瘤效应的影响

【目的】探讨珍贵用材树种花榈木幼苗接种根瘤菌的有效方法。【方法】设计了浸种、浸根、拌种和浇灌4种接种方式进行盆栽试验,以不接根瘤菌的盆栽苗为对照,观察接种后幼苗根系形态、结瘤数量变化,并测定幼苗生长、生理生化指标及固氮相关指标。【结果】不同接种方式处理下花榈木幼苗根系松软、呈土黄色,幼瘤多呈球形、黄褐色,结瘤部位多位于侧须根系上。不同接种方式处理的花榈木幼苗结瘤数量和质量差异明显,浇灌处理的结瘤数量最多,鲜瘤生物量最大,结瘤率最高,其次是浸根处理。接种上根瘤的花榈木幼苗生长指标均大于CK,与CK相比,4种接种方式处理下的苗高、地径和总生物量增幅分别为11.48%～29.51%、3.21%～26.61%和36.30%～148.18%; 总根长、总根表面积、根平均直径、总根体积和根尖数增幅分别为70.62%～139.39%、74.70%～140.97%、164.28%～200.00%、75.00%～250.00%和28.03%～167.42%。不同接种方式处理的花榈木结瘤幼苗生理生化指标差异显著,浇灌处理的花榈木结瘤幼苗叶绿素含量、硝酸还原酶活性、硝态氮含量和根系活力都明显高于其他处理。接种上根瘤的花榈木幼苗叶片全氮、鲜瘤豆血红蛋白含量、总氮量以及固氮量明显高于CK,浇灌和浸根处理优于其他处理。【结论】花榈木根瘤接种的适宜方式为用萌发种子浸根和用菌液浇灌长出真叶后的幼苗。     

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.     

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.     

A computer generator for randomly layered structures

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

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     

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.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

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.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to