不同高程对藤壶附着红树幼林的影响

对厦门曾营人工红树林生态修复区的秋茄(Kandelia candel)和白骨壤(Avicennia marina)植株上藤壶群落进行周年调查.结果表明:藤壶在红树植物秋茄和白骨壤植株上的分布具有一定的规律性.藤壶的数量随红树植株所处滩涂高程和树层的增高而锐减.藤壶的附着量变化与季节变化有相当密切的关系.秋茄和白骨壤受藤壶危害程度存在一定差异.本研究为红树林生态恢复时林地的滩涂高程选择,以避免藤壶危害提供科学依据.     

汞和盐度对三种红树种苗生长影响初探

用含汞海水处理桐花树、白骨壤和秋茄的种苗,10.0ppm汞对白骨壤种苗的萌芽时间没有延缓作用,但却影响了桐花树和秋茄的萌芽时间,1.0ppm汞对三种红树种苗的生长没有表现出毒害作用在含汞的盐度为8.75‰和17.5‰的稀释海水培养下,秋茄种苗的生长在二者之间差异不显著,但盐度为17.5‰海水延缓了白骨壤种苗的萌芽时间,抑制了桐花树的萌芽,培养100 d的白骨壤,苗高和重量在两种盐度的稀释海水之间的差异不显著,但桐花树的却差异显著,这表明秋茄和白骨苗种对壤盐度的适应范围较桐花树为宽.     

红树林内生真菌的抗肿瘤活性

从红树植物秋茄、桐花树和白骨壤树皮样品中分离出125株内生真菌。采用MTT法对其体外抗肿瘤活性进行检测,发现11株红树植物内生真菌对KB(人口腔上皮癌)或HL-60(人白血病)细胞具有显著的抑制活性,占总分离菌株的8.8％。秋茄、桐花树和白骨壤的抗肿瘤活性菌株分别占供测菌株的11.6％、5.7％和4.8％。抗肿瘤活性菌株主要分布在拟青霉属及曲霉属。在所分离的菌株中,归属于拟青霉属的活性菌株占供测菌株的比例最高、活性最强。结果显示红树植物内生真菌是潜在的抗肿瘤药物资源。     

雷州半島的紅樹植物群落

1.红树喜生於没有浪潮直接冲激而富淤泥的海滩上,不同的种类对沉积鹽土有不同的要求,如白骨壤可以广泛生长在沙滩和石隙。有些可以在潮水淹没不到的地方生长如木欖、海漆等。至於桐花树较喜欢生长於河流出口处。2.雷州半岛的红树群落属於马来亚的类型,但种类简单,属于红树科的种类只有木欖(Bruguiera conjugata)、红茄苳(Rhizophora mucronata)、秋茄树(Kandeliacandel)和角果木(Ceriops tagal)。其他科的有海漆(Excoecaria agallocha)、白骨壤(Avicennia marina)、桐花树(Aegiceras corniculatum)、欖李(Lumnitzera racemo-sa)、老鼠簕(Acanthus ilicifolius)、和金蕨(Acrostichum aureum)。此外尚有所谓半红树的种类。一般植株亦矮小,最高不过6米。种类简单而矮小的原因是由於雷州半岛已是红树林在北纬分布极限的边缘,温度年较差大,低温的持续时间较长所致。3.红树植物的形态结构有三个不同的类型。具呼吸根的以白骨壤为代表,具支柱根的以红茄苳及秋茄为代表,具板根的...     

红树林滩涂海水种植-养殖生态耦合系统初步研究

为探讨红树林对养殖水体的净化效应以及对养殖动物生长的影响,选择3种红树植物海桑Sonneratiacaseolaris、秋茄Kandelia candel和桐花树Aegiceras corniculatum构建滩涂海水种植-养殖生态耦合系统.系统设置9个试验塘和1个对照塘,试验塘按45%、30%或15%的面积比例种植一种红树植物,对照塘不种红树植物,所有养殖塘均统一养殖美国红鱼Sciaenops ocellatus和星洲红鱼Labidochromis flavigulus.通过系统运行18个月的生态监测显示,海桑和桐花树生长较好,对环境的适应能力强,秋茄生长差,成活率低;红树植物对养殖海水具有净化作用,其中桐花树的净化效果最好,其次为秋茄;系统中鱼的生长状况与红树植物的净化效应密切相关,在种植桐花树的养殖塘美国红鱼和星洲红鱼生长快,秋茄养殖塘次之,海桑养殖塘的美国红鱼不及对照塘.初步研究结果表明,在红树林滩涂海水种植-养殖生态耦合系统中,桐花树具有推广示范价值;海桑应减少种植面积比例和单位面积种植密度;秋茄生长慢,适应性差,不宜推广.     

广西红树林上大型固着污损动物的种类组成及分布

野外定性调查结果表明,广西沿海红树林区有11种红树林上固着动物,它们分属3门4纲6属,其中藤壶、牡蛎和黑荞麦蛤为主要危害种类。开阔海岸红树林较封闭港湾红树林更易遭受固着动物危害。固着动物对红树植物的附着具有选择性,附着机率是桐花树 > 秋茄 > 红海榄 > 白骨壤。就红树群落而言,固着动物的种类由海缘到陆缘,由树的低层处到高层处而减少。最后,讨论了固着动物和一些生态因子的关系。     

广西红树植物群落特征的初步研究

从生境条件、种类组成、类型、外貌、结构、物种多样性和演替等方面系统地分析广西红树植物群落的生态特征。广西红树植物群落的建群种有白骨壤、桐花树、秋茄、红海榄、木榄、海漆、老鼠Ｌｅ和银叶树８种。主要群落可划分为８个群系,１５个群落类型。群落外貌由单叶、革质、中型叶的高位芽植物决定。群落层次结构简单,单层或两层。组成群落的红树植物的物种多样性较低。随着海平面的相对降低和土壤理化性质的改善,红树植物群落具     

厦门滨海湿地红树林资源与互花米草入侵分布

通过无人机巡视、卫星遥感图像分析及沿海岸地面调查等方式,研究了2017年厦门滨海湿地红树林资源及互花米草的入侵情况。结果表明:1)厦门湾共有真红树林植物5科7属7种,分别为秋茄(Kandelia obovata)、白骨壤(Avicennia marina)、桐花树(Aegiceras corniculatum)、木榄(Bruguiera gymnorrhiza)、红海榄(Rhizophora stylosa)、无瓣海桑(Sonneratia apetala)和拉关木(Laguncularia racemosa),其中秋茄和白骨壤为优势种; 2)厦门红树植物分布在思明、湖里、集美、海沧和翔安5个行政区,面积共76. 1 hm2,其中翔安区下潭尾站位的红树林面积最大(50. 4 hm2),占厦门红树林总面积的66. 33%,目前厦门红树植物的人工恢复与重建以秋茄纯林,以及秋茄和无瓣海桑混交种植为主; 3)厦门互花米草入侵面积约69. 7 hm2,81. 42%分布在翔安区大嶝大桥两侧和九溪河口海域。根据调查结果,提出了关于厦门红树林恢复重建与互花米草控制的两点建议:1)在加强白骨壤苗种繁育技术及红树幼苗藤壶防治技术研究的基础上,大力种植本地种秋茄和白骨壤,以生态方法控制互花米草的蔓延; 2)加强对外来物种无瓣海桑和拉关木的种植地点、种植时间和种植数量等信息的登记制度,建立一定的防控机制。     

红树植物繁殖器官发育过程中铁钼锌元素的含量变化

探讨了显胎生红树植物木榄(Bruguiera gymnorrihiza)、秋茄(Kandelia obovata)、隐胎生红树植物白骨壤(Avicennia marina)、桐花树(Aegiceras corniculatum)和非胎生红树植物木果楝(Xylocarpus grantum)的繁殖器官发育过程中铁(Fe)、钼(Mo)、锌(Zn)元素的含量变化.结果表明:在花蕾期,除白骨壤外,其他种类Fe元素含量相近,在0.035 2～0.045 4 μg/mg之间.隐胎生红树植物白骨壤、桐花树中Fe元素含量在种子期最高,分别为0.090 2和0.073 3 μg/mg,萌发后呈现降低的趋势,在胚轴成熟期达到最低.在种子期,Mo元素含量在胎生红树植物中差异不大,在0.288 2～0.302 0 ng/mg之间,平均为0.294 5 ng/mg,明显高于非胎生红树植物木果楝0.105 6 ng/mg.种子萌发后,胎生红树植物中Mo元素含量下降.在同一时期,胎生红树植物种子的Mo元素含量明显大于木果楝.在木果楝的繁殖器官发育过程中,Zn元素含量逐渐下降,且比同期的胎生红树植物低.     

广西红树群落的数量分类

本文应用系统聚类分析方法,对广西红树群落进行了中级分类单位的划分。根据《中国植被》确定的分类原则、单位和系统,广西的红树群落可划分为6个群系:(1)白骨壤群系;(2)秋茄群系;(3)海漆群系;(4)木榄群系;(5)桐花树群系;(6)红海榄群系。同时,对这些群系特征作了简要的描述。     

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