中国近海早第三纪海侵层序及地层对比   总被引：1，自引：0，他引：1  

彭世福 《海洋地质与第四纪地质》1992,(1)

中国近海各盆地,据古生物群及沉积特征,在早古新世为陆相沉积,至中晚古新世时为第Ⅰ海侵期。早始新世时为海退期,至中晚始新世为第Ⅱ海侵期。早、中渐新世时为海退期,晚渐新世为第Ⅲ海侵期。在论证地层时代时结合海侵的划分,提出新的见解。海相夹层可作为地层对比的重要标志层。  相似文献   

中国和越南青蟹线粒体16S rRNA基因序列分析   总被引：13，自引：0，他引：13  

王玉江  高天翔  韩志强  刘进贤  于常红 《中国海洋大学学报(自然科学版)》2005,35(4):554-558

为确定我国青蟹的分类地位及其资源的合理利用与保护提供理论依据，对中国和越南青蟹的线粒体16S rRNA基因片段序列进行了测定，并同Genbank中其他青蟹的序列进行了比较，分析研究了青蟹种内和种间的遗传差异及其分类地位。结果显示：中、越青蟹个体间序列差异极小，与Genbank中Scylla paramamosain同源片段序列的相似性达到99％以上．而与其他3种青蟹的差异达3．91％～8．41％。所得序列与S．paramamosain，S．serrata，S．olivacea及s．tranquebarica的遗传距离分别为0．002，0．075，0．087，0．042，种间遗传距离远大于种内距离。序列特征、遗传距离和系统进化分析结果都表明本文研究的中国和越南青蟹均为S．paramamosain。  相似文献   

6种笛鲷属鱼类Cyt b基因片段序列的比较   总被引：10，自引：0，他引：10  

周发林  江世贵  苏天凤  吕俊霖 《热带海洋学报》2004,23(4):87-92

采用聚合酶链式反应直接测序法，获得紫红笛鲷(Lutjanus argentimaculatus)、白星笛鲷(L．stellatus)、千年笛鲷(L．sebae)、勒氏笛鲷(L．russelli)、红鳍笛鲷(L．erythropterus)5种笛鲷属鱼的线粒体细胞色素b(Cyt b)425bp序列，并结合基因库中的斜带笛鲷(L．decussatus)Cytb同源序列进行比较分析，共发现88个核苷酸位点存在变异(20．7％)。用MEGA2．1软件中的Pairwise distance工具计算了6种笛鲷属鱼类的相对遗传距离，表明6种笛鲷属鱼类的序列差异在0．096-0．129之间，其中红鳍笛鲷和紫红笛鲷序列差异最大为0．129，千年笛鲷与红鳍笛鲷的序列差异最小为0．096；序列变异的转换／颠换比值较低，平均只有2．160。  相似文献   

黑鲷DMRT1基因cDNA片段的克隆和序列分析     

刘绪生  梁冰  王日昕  吴常文  张树义 《台湾海峡》2004,23(3):318-322

根据其他鱼类DMRT1基因中的保守序列设计了一对简并引物 ,利用反转录 多聚酶链式反应 (RT PCR)的方法克隆了黑鲷 (Acanthopagrusschlegeli)DMRT1基因cDNA的一个片段 .该片段长 13 8bp ,推导的氨基酸序列由 45个氨基酸残基组成 .同源性分析表明 ,该cDNA片段与其他鱼类DMRT1基因序列具有较高的同源性  相似文献   

Application of Subbottom Profiler for Coastal Engineering     

Zhang Jincheng  Cai Aizhi  Guo Yifei  Shi Qiang 《中国海洋工程》1996,(2)

Experimental studies have been conducted on the acoustic effects of KLEIN-510 subbottom profiler for different sedimentary layers in estuary and bay areas. Sedimentary layer boundaries can be recorded clearly and continuously by this instrument and then compared with the results from drilling cores to reveal some variations of sedimentary environments. With this instrument, the average deposit rate can be determined and the bed-rock beneath the sea bottom can be found out.  相似文献   

Attenuated basin‐margin sequence stratigraphy of the Palaeoproterozoic Calvert and Isa Superbasins: The Fickling Group,southern Murphy Inlier,Queensland     

B. E. Bradshaw  J. F. Lindsay  A. A. Krassay  A. T. Wells 《Australian Journal of Earth Sciences》2013,60(3):599-623

Sedimentary rocks of the Palaeoproterozoic Calvert and Isa Superbasins are exposed across a large area of northern Australia. Despite the extent of the exposures there is little to indicate the nature of the basin margins as most outcrop boundaries are structurally or erosionally defined, or the margins, where preserved, are concealed beneath younger basins. The Murphy Inlier, which forms the boundary between the Mt Isa and McArthur Basins, is unique in that on its southern flanks a basin‐margin succession is well‐preserved as the Fickling Group. A detailed sequence‐stratigraphic analysis of outcrop sections and well logs, supplemented by seismic reflection profiles and SHRIMP U–Pb zircon ages, shows that all seven supersequences of the Isa Superbasin and one supersequence from the older Calvert Superbasin are represented in the Fickling Group. Through this high‐resolution sequence‐stratigraphic framework, it is possible to accurately correlate chronostratigraphically equivalent strata from the McNamara Group on the central Lawn Hill Platform to the Fickling Group on the southern Murphy Inlier. Each supersequence thins substantially from the McNamara Group (～11 km thick) to the Fickling Group (<1 km thick). The combined effects of truncation and onlap of sequences over the Murphy Inlier basement high are responsible for the thinning. Major time breaks of up to 25 million years occur between supersequences in the Fickling Group. Erosional hiatuses are often manifested at the base of supersequences as conglomerate beds composed of silicified detritus from older strata. Sequences in the Fickling Group were generally deposited in a proximal basin‐margin setting, while sequences in the McNamara Group were deposited in distal basin depocentres. The proximal depositional setting of Fickling Group sequences reduces the number of thick carbonaceous shale and siltstone intervals, which often host Zn–Pb–Ag and Cu deposits in the McNamara Group. Many host sequences from the McNamara Group are also absent in the Fickling Group due to truncation and onlap pinchout. Consequently, the economic potential of Palaeoproterozoic strata on the southern Murphy Inlier is less than equivalent strata from the central Lawn Hill Platform. Despite this, potential does exist for future discoveries of economic mineral deposits in the Mt Les Siltstone and Walford Dolomite units of the Fickling Group.  相似文献   

Assessment of hydrodynamic simulation results for eco‐hydraulic and eco‐hydrological applications: a spatial semivariance approach     

Nicholas J. Clifford  Philip J. Soar  Oliver P. Harmar  Angela M. Gurnell  Geoffrey E. Petts  Joanne C. Emery 《水文研究》2005,19(18):3631-3648

Output from a three‐dimensional numerical flow model (SSIIM) is used in conjunction with high‐resolution topographic and velocity data to assess such models for eco‐hydraulic applications in river channel design and habitat appraisal. A new methodology for the comparison between field measurement and model output is detailed. This involves a comparison between conventional goodness‐of‐fit approaches applied to a spatially structured (riffle and pool) sample of model and field data, and a ‘relaxation’ method based upon the spatial semivariance of model/field departures. Conventional assessment indicates that the model predicts point‐by‐point velocity characteristics on a 0·45 m mesh to within ±0·1 m s⁻¹ over 80% of the channel area at low flow, and 50% of the area at high in‐bank flow. When a relative criterion of model fit is used, however, the model appears to perform less well: 60–70% of channel area has predicted velocities that depart from observed velocities by more than 10%. Regression analysis of observed and predicted velocities gives more cause for optimism, but all of these conventional indicators of goodness of fit neglect important spatial characteristics of model performance. Spatial semivariance is a means of supplementing model appraisal in this respect. In particular, using the relaxation approach, results are greatly improved: at a high in‐bank flow, the model results match field measurements to within 0·1 m s⁻¹ for more than 95% of the total channel area, provided that model and field comparisons are allowed within a radius of approximately 1 m from the original point of measurement. It is suggested that this revised form of model assessment is of particular relevance to eco‐hydraulic applications, where some degree of spatial and temporal dynamism (or uncertainty) is a characteristic. The approach may also be generalized to other environmental science modelling applications where the spatial attributes of model fits are of interest. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Sequences Characterization of Microsatellite DNA Sequences in Pacific Abalone(Haliotis discus hannai)   总被引：1，自引：0，他引：1  

Kijima Akihiro 《中国海洋大学学报(英文版)》2007,(1)

1 Introduction Microsatellites or simple sequence repeats (SSRs) are tandemly repeated motifs of one to six bases found in all prokaryotic and eukaryotic genomes analysed to date (Zane et al., 2002). Due to their hyper-variable and co-dominant nature, relatively high abundance and random distribution in the genome, microsatellites are among the most efficient class of molecular markers. Such repeats display high polymorphism because of variation in repeat length and can be rapidly analysed t…  相似文献   

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许振栋  罗家天  余庆旺  陈秋英  许事群  陈传昌 《大地测量与地球动力学》2007,27(3):106-112

?????????????????????????????????з???????????????????????????????????????????????????? ???????о???????? 1996??4??21???????ML4.1????????????????????????????????????3????????????????????С??  相似文献   

Rotation Periods of Nine ROSAT Selected Solar-Type Stars     

Li-Feng Xing Shuang-Yi Zhao Wei Su Yan Shen Xiao-Bin Zhang Jian-Yan Wei 《中国天文和天体物理学报》2007,7(4):551-557

We monitored 16 X-ray selected young solar-type stars for light variation and found appreciable periodic light variability with amplitudes of a few hundredths of a magni-tude in nine of the objects. Using the method of Phase Dispersion Minimization (PDM) and Fourier analysis (software PERIOD04), the rotation periods of these stars were determined from the photometric data. The rotation periods of all nine stars are shorter than about 3days. It is suggested that, as with the Pleiades cluster, small amplitude light variations are quite common among young solar-type stars with rotation periods around 3 days or less. This gives further evidence for the spin up of solar-type stars predicted by models of angular momentum evolution of pre-main sequence stars.  相似文献