仙客来（Cyalaman persicum,Mill）组织培养中不定芽形态发生的组织细胞学研究

分别用仙客来种苗的子叶和叶柄作为外植体，培养在附加2，4－D，细胞分裂素和细胞激动素的1／2MS培养基上诱导不定芽的发生，研究了愈伤组织和不定芽形成过程中的组织细胞学变化，对两种不同外植体不定芽发生过程中的切片观察表明，两种外植体的组织脱分化始于维管束周围的维管束鞘细胞，然后开始分裂的是与其临近的薄壁细胞并能很快形成胚性分生细胞团。经30d左右的培养，进一步分化形成芽原基。子叶愈伤的芽原基通常出现在愈伤的边缘，叶柄脱分化比子叶快，不定芽可以起源于表层的分生细胞团，也可以由愈伤深处的人生组织分化而形成。     

菘蓝离体培养过程中愈伤组织和再生芽发生的细胞组织学观察

对菘蓝子叶和下胚轴在离体培养过程中的细胞分裂、分化以及器官发生进行了细胞组织学观察.研究结果 表明:培养2～5d,切口处及维管束薄壁细胞均开始脱分化,恢复分裂能力形成愈伤组织,愈伤组织表层细胞启 动分化形成芽原基.2种外植体不定芽的起源方式均为外起源.     

油菜花序轴薄层培养形态发生研究

油菜花序轴薄层切段在MS培养基上经诱导能产生愈伤组织,再经分化长出不定根与不定芽.本文研究了外植体愈伤组织形成,细胞启动的形态学特征及根芽分化的特点.实验证实花序轴启动部位多在表皮下的皮层薄壁细胞.启动细胞脱分化形成分生细胞团、分生细胞层,进一步长成愈伤组织突起.大多数分生细胞团可直接分化为不定根、不定芽.一般不定根为内起源,但亦有外起源,而不定芽多为外起源.     

黄槐叶片培养中形态分化过程的扫描电镜观察

利用扫描电镜对黄槐叶片培养中形态分化过程进行了观察。结果表明：叶片脱分化形成愈伤组织时，细胞最初进行无丝分裂其中有类似酵母的“出芽”方式的无丝分裂；愈伤组织再分化形成不定芽的过程中，最初愈伤组织表面分化出球状体，它为一顶端凹陷，具有分化潜力的细胞团，其顶端可以分化形成不定芽原基，最后发育成不定芽。球状体可以看成是具有形成不定芽能力的繁殖单位，将具有球状体与芽的愈伤组织进行继代培养，可以大量快速繁殖黄槐幼苗。     

番茄离体培养的形态发生

对番茄下胚轴、子叶、叶柄不同类型外植体离体培养中有关细胞启动、分裂、分化以及器官发生作了细胞组织学观察,结果表明：番茄不同类型外植体在不同样的培养条件下,愈伤组织生长表现明显差异：下胚轴、子叶诱导产生愈伤组织时,细胞启动早,生长快,分裂方式基本为无丝分裂;下胚轴诱导愈伤组织形成时,细胞不规划的无丝分裂少于子叶,故下胚轴离体培养得到正常芽的比例高于子叶;番茄离体培养中不定芽通常发生在愈伤组织的周边区,也可起源于维管组织结节周围,形成层状细胞。不定根则由茎中柱鞘处发生。     

甘薯叶组织培养细胞分化及根的发生

以甘薯叶片为外植体进行无菌培养,研究其细胞早期分化、愈伤组织形成及根的发生过程.甘薯叶片在MS 或N_6培养基中,在30～33℃时诱导率高达98%以上,培养三天便开始启动,启动部位有三:首先在切口边缘膨大,该处叶肉细胞脱分化转变为分生细胞;其次是叶脉韧皮薄壁细胞,细胞体积加大,数目增多,核大、质浓;同时某些栅栏细胞活化,细胞变园变扁,层次加多。培养6～12天的叶片,被启动细胞进入细胞分裂期,有的形成薄壁细胞突起,将表皮外推,叶脉处的分生细胞,形成蛛网状的分裂生长中心。培养5～12天的叶片,进入细胞分化期,愈伤组织中的分生细胞再分化为薄壁细胞及管状分子。培养25～30天的叶片,在愈伤组织中随机出现胚性细胞,形成分生细胞团,由此产生根原基,根原基多点发生,位置不定,一般为内起源。     

南蛇藤茎段培养中芽的形态发生

本文报道对南蛇藤离体茎段培养中不定芽的形态发生所进行的研究。以MS基本培养基附加萘乙酸(NAA)0.01毫克/升和6-苄基嘌呤(6BA)2毫克/升进行培养,结果大量地促进了芽的发生。单独加入细胞分裂素6BA2毫克/升,也能促进芽的分化,如果同时加入低浓度生长素NAA,更有利于芽的形成。由茎段表面得到的肿胀状愈伤组织,较专一地起源于远离茎段切口的表皮或下皮层细胞。不定芽一般来自于愈伤组织表层的分生细胞团,有时芽原基的诱导还与维管组织结节有联系。芽原基可以起源于表皮细胞或下皮细胞,然从下皮细胞诱导来的芽,其芽的生长更为迅速。     

离体培养中黄槐叶片细胞脱分化的细胞学观察

黄槐叶片外植体接种于 MS+2,4-D 1 ppm+NAA 1 ppm+6-BA 2 ppm 培养基上,外植体的维管薄壁细胞及维管束鞘细胞先脱分化启动,而后栅栏组织细胞脱分化,进而形成愈伤组织.细胞脱分化启动时有两个明显特点:一是细胞质变浓,核相对变大,核仁明显;二是细胞开始积累淀粉.细胞脱分化过程中细胞分裂方式以无丝分裂为主,有丝分裂较少.通过观察无丝分裂的主要过程,可以认为它是典型的劈裂式无丝分裂.文中还对两种细胞分裂方式在愈伤组织形成中的意义进行了讨论.     

水仙鳞茎组织培养中小鳞茎形态发生的初步研究

本文以一、二年生的水仙(Narcissus tazetta var.chinensis Roem.)的鳞茎为外植体,通过不同切割方式和两种培养基进行组培试验。试验结果表明,小鳞茎的形态发生有两种途径:带茎盘的二年生鳞茎切块和一年生鳞茎外层切块,可以在鳞片间的茎盘组织表层直接形成芽原基,然后发育成小鳞茎;不带茎盘的鳞片切块和带茎盘的一年生鳞茎的内层切块,都要先形成愈伤组织,由愈伤组织团分化出芽原基,再发育成小鳞茎。两种培养基对小鳞茎发育途径的影响无明显差异。组织学观察表明,直接从茎盘表层发生的芽原基,不是培养前原来就有的,而是在切割损伤刺激下,由茎盘表层组织脱分化形成的。     

木槿幼叶培养再生植株的细胞组织学研究

以木槿(Hibiscus syriacus)幼叶为外植体,培养在附加6-BA_3+IAA(或IBA)_(0.1)+GA_(0.5)+LH_(100)的1/2MS培养基上,通过细胞组织学观察表明:接种3—10天,接触培养基的细胞体积增大,核染色加深,并移向细胞中央,有的细胞已开始分裂,接种15—20天,表皮,叶肉的栅栏细胞、海绵细胞,以及维管束附近的薄壁细胞等,都有细胞分裂,并形成愈伤组织,培养30天后,叶片结构紊乱,形成大量的分生细胞团或细胞群。同时,还有维管分子、维管组织结节,以及芽原基和叶原基的相继出现,芽原基进一步培养,形成无根苗,转移无根苗到生根培养基上,20天后,可形成完整再生植株,其结构与正常木槿植株一致。     

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