检索结果-南通市图书馆

Modern microbialites and their environmental signifi-cance,Meiji reef atoll,Nansha (Spratly) Islands,South China sea

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2008年第4期51卷 608-617页

作者： SHEN JianWei1 & WANG Yue1,2 1 Department of Marine Geology, South China sea.Institute of oceanology Key Laboratory of Marginal sea.Geology, South China sea.Institute of oceanology and Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510301, China 2 Graduate University of the Chinese Academy of Sciences, Beijing 100049, China Department of Marine Geology South China Sea Institute of Oceanology Guangzhou China Key Laboratory of Marginal sea.Geology South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Graduate University of the Chinese Academy of Sciences Beijing China

Meiji (Mischief) coral atoll, in Nansha (Spratly) Islands, South China sea. consists of an annular reef rim surrounding a central lagoon. on the atoll rim there are either protuberant 'motu' (small coral patch reefs on the rim of atoll) islets or lower sandy cays that contain modern microbialite deposits on the corals in pinnacles and surrounding bottoms of the atoll. Microbialites, including villiform, hairy, and thin spine growth forms, as well as gelatinous masses, mats and encrustation, developed on coral colonies and atoll rim sediments between 0 and 15 m deep-water settings. The microbialites were produced by natural populations of filamentous cyanobacteria and grew on (1) bulbous corals together with Acropora sp., (2) on massive colonies of Galaxea fascicularis, (3) on dead Montipora digitata, and (4) on dead Acropora teres, some hairy microbialite growing around broken coral branches. This study demonstrates that microbial carbonates are developed in coral reefs of South China sea.and indicates that microbial processes may be important in the construction of modern reef systems. The results have significance in the determination of nature and composition in microorganisms implied in the formation ancient microbialites, and permit evaluation of the importance of microbial deposits in mo-dern coral reefs and of 'microbialites' in biogeochemical cycles of modern coral reef systems. The re-sults also provide evidence of modern analogues for ancient microbialites in shallow-water settings, and combine with sedimentological studies of ancient microbialites to understand their controls.

关键词： Microbialite Meiji reef Nansha Island South China sea

Influence of Kuroshio water on the distribution of dissolved oxygen in the northern East China sea

在线全文

学校读者我要写书评

暂无评论

Acta oceanologica Sinica 1992年第2期11卷 305-316页

作者： Fu YongfaNorth sea.Branch of State oceanic Administration, Qingdao, China

on the basis of the four-cruise investigation data of the Kuroshio by the R/V "Xiangyanghong 09", this paper lays stress on the discussion of the relationship between the Kuroshio current systems, the distribution of ... 详细信息

关键词： dissolved sea.onal discussion cruise winter isotherm salinity diluted mixing suspended

Identification and analysis of shear waves recorded by three-component oBSs in northeastern South China sea

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第2期18卷 181-188页

作者： Minghui Zhao ,Xuelin Qiu,Shaohong Xia,Ping Wang,Kanyuan Xia,Huilong Xu Key Laboratory of Marginal sea.Geology,South China sea.Institute of oceanology,Chinese Academy of Sciences,Guangzhou 510301,China Key Laboratory of Marginal sea.Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China

Structure models associated with P-and S-wave velocities contain considerable amount of information on lithology and geophysical properties,which can be used to better understand the complexity of the deep crustal structure. However,records of converted shear waves are less due to the speciality of seismic survey at sea.and the rigorous generated conditions. The study on shear waves has always been a weakness for studying the deep crustal structures of South China sea.(SCS). In this paper,eleven three-component oBSs were deployed along the Profile oBS-2001 in northeastern SCS. After the data processing of polarization and band-pass filter,converted S-wave phases were identified in the radical component records of nine oBSs. Taking the oBS7 as an example,identification and analysis of converted shear waves were presented and discussed in detail. A few phase groups,such as PwSc,PgSs,PnSc,PmS,and PwSn,were found coming from the deep crust or Moho interface by simple theoretical model calculation and ray-tracing simulation. The results not only provide the underlying basis for studies of S-wave velocity structure and Poisson’s ratio structure,but also reveal the relationship between crustal petrology and seismology,which will be of importance for making full use of S-wave information in the future.

关键词： Converted shear wave Deep crustal structure Three-component ocean bottom seismometer Northeastern South China sea

Assessment of coral bleaching using symbiotic zooxanthellae density and satellite remote sensing data in the Nansha Islands,South China sea

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第10期56卷 1031-1037页

作者： LI Shu,YU KeFu,CHEN TianRan,SHI Qi & ZHANG HuiLing CAS Key Laboratory of Marginal sea.Geology,South China sea.Institute of oceanology,Chinese Academy of Sciences Guangzhou 510301,China CAS Key Laboratory of Marginal sea.Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China

Coral bleaching,characterized by a significant loss of symbiotic zooxanthellae,is the primary cause of mass coral mortality and reef degradation throughout the *** characteristics,processes,and resistance of corals to bleaching varies significantly and is dependent on environmental *** documented a mass coral bleaching event in June 2007 at the Meiji and Zhubi Reefs,Nansha Islands (NS),South China sea.using ecological surveys and measurement of coral zooxanthellae density and sea.surface temperatures (SST).More than 35 species of corals (between 0-20 m in depth) were *** bleached corals accounted for 15.6% of total corals in the investigated *** branching corals Pocillopora and Acropora were the most vulnerable species whereas the massive corals Porites and Favia were more tolerant of the high ***,we found no evidence of bleaching in Agariciidae corals suggesting that this family is resistant to thermal *** bleached corals had lost 72%-90% of their symbiotic ***,corals that had no visual signs of bleaching had also lost 31%-53% of their zooxanthellae suggesting that most corals were experiencing the early stage of *** monthly mean SST during June 2007 was 30.8°C,the highest since *** on measurements of SST and the Hotspots and DHW data (NoAA),we conclude that it the extremely high SSTs triggered this coral bleaching *** results suggest that the previously accepted temperature thresholds used to predict coral bleaching based on satellite data are likely to underestimate the extent and intensity of coral bleaching,at least in the NS.

关键词：珊瑚礁南沙群岛中国南海卫星遥感数据漂白黄藻密度共生

Use of subword tokenization for domain generation algorithm classification

在线全文

学校读者我要写书评

暂无评论

Cybersecurity 2024年第2期7卷 1-12页

作者： sea.Ran Cleon Liew Ngai Fong Law University of Waterloo WaterlooCanada Department of Electrical and Electronic Engineering The Hong Kong Polytechnic UniversityKowloonHong Kong

Domain name generation algorithm(DGA)classification is an essential but challenging *** feature-extract-ing machine learning(ML)methods and deep learning(DL)models such as convolutional neural networks and long short-term memory have been ***,the performance of these approaches varies with different types of *** features in the ML methods can characterize random-looking DGAs better than Word-looking *** improve the classification performance on word-looking DGAs,subword tokenization is employed for the DL *** experimental results proved that the subword tokenization can provide excellent classification performance on the word-looking *** then propose an integrated scheme that chooses an appropriate method for DGA classification depending on the nature of the *** show that the integrated scheme outperformed existing ML and DL methods,and also the subword DL methods.

关键词： Botnet detection Domain names Network security Machine learning-based botnet detection

The distribution characteristics of clay minerals in the northern South China sea

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta oceanologica Sinica 1993年第1期12卷 145-157页

作者： Tang Zhili and Wang Youqiang South China sea.Institute of oceanology, Academia Sinica, Guangzhou 510301, China South China sea.Institute of oceanology Academia Sinica Guangzhou 510301 China

The clay minearals are composed of illite, chlorite, kaolinite, montmorillonite and mixed-layer minerals in the submarine sediments of the northern South China sea. Three types of clay mineral zone can be recognized on the basis of the distributive regularity of clay minerals, submarine relief, hydrodynamic conditions and depositional characteristics in this region. Apart from the northern mainland source, kaolinites carried from the Philippines volcanic arc in the east and Malaysia in the south are also assumed to be one of the sources of the clay minerals in the deep sea. The increase of chlorites to the abyssal direction in the west of 116° E might be associated with the residual chlorites carried from the ancient Zhujiang River during the glacial period and the conversion of kaolinite into chlorite submarine volcanoes appear to be one of the sources of the increment of montmorillonite and chlorite around the Huangyan Island. From the distribution pattern of clay minerals in the whole area, it is known that the types of clay mineral assemblage in the study area are mainly controlled by climate and rock types of the source are-

关键词： The distribution characteristics of clay minerals in the northern South China sea

Late Neogene radiolarian absence event in the southern South China sea.and its paleoceanographic implication

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第3期18卷 281-287页

作者： Lili Zhanga,b, Muhong Chena, Lanlan Zhanga,b, Jun Lua, Rong Xianga a Key Laboratory of Marginal sea.Geology, South China sea.Institute of oceanology, Chinese Academy of Sciences, Guangzhou 510301, China b Graduate University of Chinese Academy of Sciences, Beijing 100039, China Key Laboratory of Marginal sea.Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China Graduate University of Chinese Academy of Sciences Beijing 100039 China

Down-core variations of radiolarians at oDP Site 1143 in the southern South China sea.(SCS) are presented for the last 12 Myr. The fluctuations of radiolarian abundances since the Late Miocene can be divided into three stages: a high abundance stage at 12-5.96 Myr, a radiolarian absent stage at 5.96-3.30 Myr and a gradual increasing stage after 3.30 Myr. The three stages correspond to the forming and vicissitudes of the Western Pacific Warm Pool (WPWP) and the Eastern Asian Summer Monsoon (EASM). The radiolarian absence event (RAE) was also absent of diatom and occurred nearly simultaneously with the closures of the Panama Isthmus and the Indonesian sea.ay, which probably caused the reorganization of oceanic circulation systems. Accompanied this circulation reorganization was the weakening of the WPWP and the EASM, which probably led to a weakened upwelling in the southern SCS. In addition dissolved silica (Dsi) content in surface sea.ater might be very low during 5.96-3.30 Myr due to the ’’biogenic bloom" event, which consumed a large amount of Dsi in the surface sea.ater. All these factors together might lead to a great decrease of siliceous production in the southern SCS and consequently caused the RAE. Moreover, the dissolution of siliceous skeletons might also influence the abundance of radiolarians.

关键词： Southern South China sea Late Neogene Radiolarian absence event

A preliminary analysis on lithospheric thickness and crustal ages in central basin of South China sea

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta oceanologica Sinica 1997年第1期16卷 85-107页

作者： Chen Xue and Lin Jinfeng South China sea.Institute of oceanology, the Chinese Academy of Sciences, Guangzhou 510301, China South China sea.Institute of oceanology Chinese Academy of Sciences Guangzhou 510301 China

The models about lithospheric thickness and thermal conduction inside the lithosphere and the top layer of the asthenosphere have been proposed in this study for four type regions: the midoceanic ridge, the extinct spreading ridge, the lithospheric fault fissure and the mouth of the extinct submarine volcanoes which are in deep sea.bottom. The solutions of the models are found to be the same. The formulas of temperature distribution inside the lithosphere and the top layer of the asthenosphere, the lithospheric thicknesses to the heat flow and the crustal ages to the heat flow are obtained. The crustal ages and the lithospheric thicknesses of the central basin are calculated. And they are used to draw the lithospheric thicknesses and crustal ages maps of the central basin (in this paper both the central basin and the basin are the central basin of the South China sea.. According to their characteristics, the central basin is divided into three regions. The lithospheric thicknesses, crustal ages and heat flow distribution characteristics are discussed respectively. The formation and evolution of the South China sea.are analysed and it is thought that the South China sea.has undergone three episode-sea.loor spreadings.

关键词： Thermal conduction equation lithospheric thickness crustal age evolution

Mathematical Development and Verification of a Finite Volume Model for Morphodynamic Flow Applications

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2011年第4期3卷 470-492页

作者： Fayssal Benkhaldoun Mohammed sea.d Slah Sahmim LAGA Universite Paris 1399 Av J.B.Clement93430 VilletaneuseFrance School of Engineering and Computing Sciences University of DurhamSouth RoadDurham DH13LEUK Laboratoire D’ingenierie Mathematique Ecole Polytechnique de TunisieB.P.743-2078 La MarsaTunisia

The accuracy and efficiency of a class of finite volume methods are investigated for numerical solution of morphodynamic problems in one space *** governing equations consist of two components,namely a hydraulic part described by the shallow water equations and a sediment part described by the Exner *** on different formulations of the morphodynamic equations,we propose a family of three finite volume *** numerical fluxes are reconstructed using a modified Roe’s scheme that incorporates,in its reconstruction,the sign of the Jacobian matrix in the morphodynamic system.A well-balanced discretization is used for the treatment of the source *** method is wellbalanced,non-oscillatory and suitable for both slow and rapid interactions between hydraulic flow and sediment *** obtained results for several morphodynamic problems are considered to be representative,and might be helpful for a fair rating of finite volume solution schemes,particularly in long time computations.

关键词： Morphodynamic model shallow water equations sediment transport finite volume method well-balanced discretization