检索结果-南通市图书馆

Current Zoology 2010年第1期56卷 90-99页

作者： rodney A.rOUNTrEE francis JUANES Marine Ecology and Technology Applications Inc. Department of Natural resource Conservation University of Massachusetts

Underwater sound and video observations were made at noon, sunset, and midnight in sand, gravel, and boulder habitat in the Stellwagen Bank National Marine Sanctuary, Gulf of Maine, USA in October 2001 using a remotely operated vehicle （rOV）. Seventeen species of fish and squid were observed with clear habitat and time differences. Observations of feeding behavior, disturbance behavior, and both interspecific and intraspecific interactions provided numerous opportunities for potential sound production; however, sounds were recorded only during a single dive. Although high noise levels generated by the rOV and support ship may have masked some sounds, we conclude that fish sound production in the Gulf of Maine during the fall is uncommon. The recorded fish sounds are tentatively attributed to the cusk Brosme brosme. Cusk sounds consisted variously of isolated thumps, widely spaced thump trains, drumrolls, and their combinations. Frequency peaks were observed at 188, 539, and 1195 Hz. Use of a remotely operated vehicle （rOV） as a passive acoustic observation platform was problematic due to high rOV self-noise and the rOV＇s inability to maintain a fixed position on the bottom without thruster power. Some fishes were clearly also disturbed by rOV noise, indicating a potential rOV sampling bias. Based on our observations, we suggest that new instruments incorporating both optic and passive acoustic technologies are needed to provide better tools for in situ behavioral studies ofcusk and other fishes [Current Zoology 56 （1）： 90-99 2010].

关键词： Passive acoustics Soniferous Gulf of Maine rOV Sound production Fish behavior

Cluster Consensus of Nonlinearly Coupled Multi-Agent Systems in Directed Graphs

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第5期27卷 36-39页

作者：路晓庆 francis Austin 陈士华 School of Mathematics and Statistics Wuhan University Wuhan 430072 Department of Appiied Mathematics The Hong Kong Polytechnic University Hong Kong

We investigate the cluster consensus problem in directed networks of nonlinearly coupled multi-agent systems by using pinning control. Depending on the community structure generated by the group partition of the underlying digraph, various clusters can be made coherently independent by applying feedback injections to a fraction of the agents. Sufficient conditions for cluster consensus are obtained using algebraic graph theory and matrix theory and some simulations results are included to illustrate the method.

关键词： cluster consensus agents cluster

A“taxonomic affidavit”:Why it is needed?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2007年第2期2卷 57-59页

作者： francis Dov POr The Scientific Collections of Natural History Life Science InstituteHebrew University of JerusalemJerusalemIsrael

Imprecise and faulty taxonomic identification of the biological objects of many ecological and experimental studies renders these studies *** identification to the species level and excessive use of vernacular species names are additional *** science must be able to be falsified.I recommend that publications and granting agencies use and mention the names of the zoologists or botanists who identified the *** specimens should be marked and deposited in scientific museums for future checking.

关键词： identification replicability taxonomic services vernacular names voucher specimens

The actuality of Lamarck: towards the bicentenary of his Philosophie Zoologique

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2006年第1期1卷 48-52页

作者： francis Dov POr Hebrew University of Jerusalem JerusalemIsrael

Lamarck,a son of the age of natural philosophy and revolutionary ideas,turned to zoology,the field in which he made his major impact,in his old *** then,the world had already shifted towards a different intellectual atmosphere and,due to this anachronism,he was snubbed and even ridiculed by the mainstream *** his basic ideas about the active role of organisms in and the progressive unraveling of evolution stubbornly survived along the academic fringes and,more importantly,among the humanistic *** developments in genetic inheritance,embryology,immunology and behavioral studies vindicate,at least in part,the 200-year-old vision of Lamarck.

关键词： Lamarck new genetics progressive evolution role of behavior

Spatiotemporal variation in the endangered Thymus decussatus in a hyper-arid environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2015年第1期8卷 79-90页

作者： Katy Thompson francis Gilbert School of Life Sciences University of NottinghamUniversity ParkNottingham NG72RDUK

Aims Arid environments are resource limited,with scarcity of water the key limiting factor,but hyper-arid environments are rarely *** test for spatial and temporal variation in ecologically important characteristics to deduce plant adaptations to the extreme *** The endangered Sinai Thyme(Thymus decussatus)exists as a set of patches on mountaintops within the St Katherine Protectorate,South Sinai,a hyper-arid environment with rare events of good rains(every 10-15 years).Important Findings From spatial and temporal patterns of plant mortality,size,condition and flowering among 10 patches on the Mt Sinai massif,we deduce that the incidence and amount of flowering responds relatively quickly(1-2 years)to rainfall fluctuations,but plant growth respond only very *** individuals are most at risk of death dur-ing drought,and a high proportion of plants were dead at the end of 8 years of very low or no *** recruitment of seedlings was observed even in years of good *** are expected to become increasingly frequent due to climate change;this may have important consequences for Sinai Thyme and also its associ-ated herbivores,such as the Critically Endangered Sinai Baton Blue(Pseudophilotes sinaicus)whose larval stage feeds exclusively upon the flowers of this plant.

关键词： spatial variation temporal fluctuations resource availability drought Egypt

Deuterobiosphere the Chemosynthetic Second Biosphere of the Globe. A First review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2008年第2期3卷 101-114页

作者： francis D.POr The Scientific Collections The Life Sciences InstituteThe Hebrew UniversityIsrael

With the discovery of Ophel, a chemosynthesis-based continental subterranean environment (Por 2007), it becameevident that such environments, previously known only from the sea , are spanning the world as a parallel biosphere,the deuterobiosphere. In this preliminary contribution the different known biomes of the deuterobiosphere arereviewed and some general and comparative features are listed.

关键词： anchialine systems chemosynthetic environments cold seeps deuterobiosphere hot vents Ophel thiobios

Squeeze casting for metal alloys and composites:An overview of influence of process parameters on mechanical properties and microstructure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2023年第2期20卷 148-158页

作者： Osarue Osaruene Edosa francis Kunzi Tekweme Kapil Gupta Department of Mechanical and Industrial Engineering Technology University of JohannesburgJohannesburgRepublic of South Africa Department of Mechanical Engineering College of Engineering and TechnologyWilliam V.S.Tubman UniversityHarperMaryland CountyRepublic of Liberia

Squeeze casting is a well-established and reliable process for fabricating high-integrity metallic alloys,bimetals,and *** quality and high performance of squeeze cast components are dependent on optimum casting *** selection of parameter values may adversely affect the quality of the *** squeeze cast components are generally subjected to secondary processing such as heat treatment,extrusion,and other bulk deformation processes to improve the microstructural features and mechanical *** treatment further refines the grains and reduces porosity,consequently improving tensile strength,and hardness;however,ductility *** paper provides a comprehensive review on studies concerning the influence of processing parameters on porosity,density,percentage elongation,strength,hardness,wear,and fracture of squeeze casting alloys,aiming to provide sufficient information on the squeeze casting process and the effects of processing parameters on product quality.

关键词： composites microstructure optimization porosity solidification squeeze casting

Structure Identification of Nonlinearly Coupled Complex Networks with Non-Delayed and Delayed Coupling

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第3期27卷 68-71页

作者：郭万里 francis Austin 陈士华 School of Mathematics and Statistics Wuhan University Wuhan 430072 Department of Applied Mathematics The Hong Kong Polytechnic University Hong Kong

Topology identification is an important problem for complex networks because much information about networks in practice such as the topological structure is uncertain. We propose an adaptive control method for identifying the topology of general nonlinearly-coupled complex network models that are either non-delayed or delayed coupled. Simulation results are also presented to illustrate the effectiveness of the method.

关键词： Mathematical physics Statistical physics and nonlinear systems

Transcription factor PDX-1 in human colorectal adenocarcinoma:A potential tumor marker?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第38期14卷 5823-5826页

作者： Nikiforos Ballian francis Charles Brunicardi the Michael E. DeBakey Department of Surgery Baylor College of Medicine 1709 Dryden Suite 1500 HoustonTX 77030 United States

AIM: To examine the expression of pancreatic duodenal homeobox-1 (PDX-1) transcription factor in human colorectal cancer. METHODS: rT-PCr, Western blotting, and immuno-histochemistry were performed to determine the expression pattern of transcription factor PDX-1 in primary colorectal tumor, hepatic metastasis, and benign colon tissue from a single patient. rESULTS: The highest PDX-1 transcription levels were detected in the metastasis material. Lower levels of PDX-1 were found to be present in the primary tumor, while normal colon tissue failed to express detectable levels of PDX-1. Western blot data revealed a PDX-1 expression pattern identical to that of mrNA expression. Immunohistochemistry confirmed high metastasis PDX-1 expression, lower levels in the primary tumor, and the presence of only traces of PDX-1 in normal colon tissue. CONCLUSION: These data argue for further evaluation of PDX-1 as a biomarker for colorectal cancer.

关键词： Colorectal cancer Pancreatic duodenal homeobox-1 Tumor marker Transcription factor Diagnostics

Status and Trends in Advanced SOI Devices and Materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2006年第4期27卷 573-582页

作者： Balestra francis Institut de Microélectronique Electromagnétisme et PhotoniqueGrenoble 38016France

A review of recently explored effects in advanced SOI devices and materials is *** effects of key device parameters on the electrical and thermal floating body effects are shown for various device *** advances in the understanding of the sensitivity of electron and hole transport to the tensile or compressive uniaxial and biaxial strains in thin film SOI are *** performance and physical mechanisms are also addressed in multi-gate Si,SiGe and Ge *** hot carrier phenomena are *** effects of gate misalignment or underlap,as well as the use of the back gate for charge storage in double-gate nanodevices and of capacitorless DrAM are also outlined.

关键词： MOSFETs 半导体场效应管疲劳效应灵敏度