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1.
实验条件下原甲藻与中肋骨条藻种间相互作用研究   总被引:2,自引:0,他引:2  
钟恢明  张健  刘力章 《江西科学》2011,29(5):593-596,677
微藻化感作用是一种极其复杂的生理、生态学现象,其在解释微藻藻种分布、群落结构及种群动力学方向起着关键作用。选择我国典型常见赤潮优势种原甲藻(Prorocentrum micans)与中肋骨条藻(Skeletonemacostatum)作为对象,研究实验室共培养条件下2种微藻种间相互作用关系。结果表明:两者以1×104 cells/mL的密度接种共培养时,原甲藻的生长状况几乎没有显著变化(F=0.004 48,P=0.947 96>0.05),而共培养的中肋骨条藻被原甲藻强烈抑制致死(F=5.116 63,P=0.047 21<0.05)。Lotka-Volterra双藻竞争模型分析知,共培养条件下原甲藻的种间竞争能力大于中肋骨条藻的种间竞争能力。在去藻滤液实验中,灭菌处理及未经灭菌处理的原甲藻去藻滤液对中肋骨条藻的生长都没有显著影响(P>0.05);中肋骨条藻-原甲藻共培养体系的去藻滤液经灭菌处理及未经灭菌处理培养中肋骨条藻时,中肋骨条藻的生长也没有显著变化(P>0.05)。可见,中肋骨条藻与原甲藻共培养时的种间相互作用,可以由细胞间的直接接触进行,而并不需要通过介质来完成。  相似文献   

2.
以分离自厦门港船舶压舱水箱及沉积底泥中的一种潜在入侵藻类-沃氏藻(Woloszynskia sp.)MMDL3013和一种常见有害赤潮藻-塔玛亚历山大藻(Alexandrium tamarense (Lebour) Balech)MMDL3041为研究对象,采用半连续培养的方法研究了不同磷酸盐浓度和藻类不同起始细胞密度两因子对这两种藻种间竞争的影响.结果表明,在磷酸盐限制条件下,沃氏藻为竞争的优势种,沃氏藻和塔玛亚历山大藻表现为资源利用性竞争;而在磷酸盐丰富的环境中种间竞争具有藻类细胞密度依赖性,起始细胞密度的不同可以影响竞争的结果.  相似文献   

3.
杨金华 《科技信息》2011,(27):345-345,373
为研究多环芳烃(PAHs)蒽(anthrancene)对青岛大扁藻(Platymonas subcordiformis.(wille)Hazen)的毒害作用,以青岛大扁藻为实验材料,在实验生态条件下,蒽质量浓度设为0,10,20,40,60,100μg/L,采用生态毒理学方法研究了蒽对青岛大扁藻生长的影响,并应用对数模型计算了其EC50值。实验结果表明,多环芳烃蒽具有抑制效应,并随着蒽浓度的不断增大,青岛大扁藻的相对增长率逐渐降低,蒽对青岛大扁藻的96h-EC50值为41.27μg/L。  相似文献   

4.
通过实验生态学的方法,研究多环芳烃(PAHs)蒽与UV-B单独对青岛大扁藻(Platymonas sub-cordiformis(while)Hazen)的毒害作用,以及两者的联合毒性效应,蒽质量浓度设为0,6.25,11.50,20.00,35.00,62.50μg/L,UV-B辐射剂量设为0,0.375,1.875,3.75,7.50J/m2.实验结果表明:对青岛大扁藻的生长,多环芳烃蒽具有抑制效应,小剂量的UV-B辐射具有刺激作用,随着剂量的增加表现出抑制作用,蒽与UV-B的联合则表现出更强的抑制作用,二者表现为协同作用.蒽对青岛大扁藻的96hEC50为11.98μg/L,在UV-B辐射(3.0J/m2)作用下的蒽对青岛大扁藻的96hEC50为10.31μg/L,UV-B辐射对青岛大扁藻的48hEC50为2.934J/m2,在蒽(33.3μg/L)作用下的UV-B辐射对青岛大扁藻的48hEC50为1.531J/m2.  相似文献   

5.
大型海藻龙须菜对两种海洋赤潮藻的生长抑制效应   总被引:2,自引:0,他引:2  
利用共培养系统研究了在不同光照强度、生物量条件下,大型海藻龙须菜(Gracilarialemaneiform is)及其水溶性抽提液对两种海洋赤潮藻旋链角毛藻(Chaetoceros curvisetus)和椎状斯氏藻(Scrippsiella trochoidea)的生长抑制效应.结果显示,龙须菜和两种赤潮藻间存在着营养竞争,受龙须菜的影响,两种赤潮藻的最大密度与对照组相比均有所下降,其受抑制程度随着龙须菜起始密度的增大而增强,而两种赤潮藻对龙须菜生长的影响却不显著.此外,龙须菜和两种赤潮藻之间还存在着光竞争,弱光条件更适合龙须菜的生长,强光条件下龙须菜对两种赤潮藻的抑制作用减弱.此外,龙须菜水溶性抽提液也会对两种赤潮藻的生长产生抑制.  相似文献   

6.
采用梯度法、正交试验L9(34)研究盐度、温度、光照强度、光照周期和氮水平对青岛大扁藻、亚心形扁藻、微绿球藻脂肪酸组成的影响.结果指出适宜于合成n-3PUFA的培养条件分别为青岛大扁藻20 ℃、1000 lx、12∶12 (LH∶DH)、2份氮水平(2×74.8mg/lNaNO3)、盐度5;亚心形扁藻为20 ℃;微绿球藻为25 ℃、4000 lx、12∶12 (LH∶DH)及2份氮水平.如果作为生物饵料,两种扁藻提供的必需脂肪酸主要是18∶3n-3,微绿球藻主要是20∶5n-3.  相似文献   

7.
丙溴磷对二种海洋微藻的GPx活性及GSH、CAR含量的影响   总被引:4,自引:0,他引:4  
实验以三角褐指藻和青岛大扁藻为材料,进行了丙溴磷农药对海洋微藻的抗氧化防御系统成份-GPx(glutatione Peroxidase)活性和GSH(glutathione),CAR(carotionid)含量的影响研究,结果表明,在丙溴磷胁迫下,微藻的GPx活性呈现下降趋势,GSH和CAR含量也一明为下降趋势,并且胁迫的时间越长,胁迫的强度越大它们下降的幅度也越大,因此微藻细胞对抗氧化防御系统的能力被消弱,从而可能导致活性氧在体内的过量产生与积累,进而对藻细胞造成更大的伤害。  相似文献   

8.
多环芳烃对2种海洋微藻的联合毒性效应研究   总被引:1,自引:0,他引:1  
本以青岛大扁藻(Platymonas subcordiformis),球等鞭金藻8701(Isochrysis galbana 8701)为试验材料,采用水生毒理联合效应指数法,比较了3种多环芳烃,蒽(anthracene),并[a]芘(benzo [a] pyrene)及1,2-苯并蒽(1,2-benzonthracene)单剂和混剂对青岛大扁藻和球等鞭金藻8701的急性毒性和联合毒性。实验结果表明:对青岛大扁藻,胁迫72h,蒽与苯并[a]芘的联合及苯并[a]芘与1,2-苯并蒽的联合为协同作用,蒽与1,2-苯并蒽的联合及蒽,苯并[a]芘与1,2-苯并蒽的联合为拮抗作用。对球等鞭金藻8701胁迫72h,苯并[a]芘与1,2-苯并蒽的联合为协同作用,其它联合均为拮抗作用。  相似文献   

9.
用1次性培养法结合Monod模型测定了大型海藻-孔石莼和海洋微藻,-亚心形扁藻磷限制下的生长动力参数,并在相同实验条件下观察2种藻类对不同磁浓度及脉冲方式的反应及竞争特征。结果显示:亚心形扁藻的种群密度随着磷脉冲的增大而增加;孔石莼在不同磷脉冲供给的培养系统中,保持基本稳定的生物量。在低磷浓度(0.16μmol/L/d)下,孔石莼成为优势种群;在磷浓度较高的情况下(0.8μmol/L/d以上),亚心形扁藻成为优势种群。亚心形扁藻为r-选择,孔石莼为K-选择。  相似文献   

10.
两种海洋微藻脂肪酸组成研究   总被引:3,自引:0,他引:3  
为了筛选多不饱和脂肪酸含量高的微藻,对两种海洋微藻,三角褐指藻(Phaeodactylum triorrutum)和等鞭金藻(Isochrysis gal-bana)进行了室内培养,并对其脂肪酸组成进行了研究。结果表明:三角褐指藻含有较高的C16:O、C16:1和C20:5(EPA),仅含有微量的C20:4不含有C22:6(DHA),多不饱和脂肪酸占总脂肪酸的23.8%。而等鞭金藻主要脂肪酸为C14:0、C16:0、C18:2、C18:3、C22:6(DHA),不含有C20:4,仅有少量的EPA,多不饱和脂肪酸占总脂肪酸的比例高达49.8%。两种微藻脂肪酸组成显示出明显的种间差异。  相似文献   

11.
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.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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。  相似文献   

14.
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  相似文献   

15.
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  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
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.  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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