检索结果-南通市图书馆

Has OpenStreetMap a role in Digital Earth applications?

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2014年第7期7卷 534-553页

作者： peter Mooney Padraig Corcoran Department of Computer Science National University of IrelandMaynoothIreland School of Computer Science and Informatics University College DublinBelfieldIreland

Volunteered geographic information(VGI),as a special subset of crowdsourcing,has provoked interest from many scientific disciplines and industry in the past few ***(OSM)is the most famous and well supported example of a VGI project on the Internet *** a technology,Digital Earth(DE)offers immediate access to enormous quantities of data and information,referenced by locations on the surface of the *** of DE’s goals is to make global spatial information ubiquitously available as an essential component of ***’s mission is well positioned within this goal where OSM aims to create a freely available editable map database of the *** paper explores the characteristics of the collaborative,crowd-based,editing of spatial data in OSM and the crowd *** provide some conclusions on how OSM can be best integrated into the fabric of DE.

关键词： OpenStreetMap Digital Earth volunteers spatial data crowdsourcing

Design considerations and behavior of reinforced concrete core dams during construction and impounding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Water Science and Engineering 2016年第3期9卷 212-218页

作者： peter Tschernutter Adrian Kainrath Institute of Hydraulic Engineering and Water Resources Management Vienna University of Technology

Reinforced concrete core dams can be an alternative solution to conventional dam designs either for permanent impounded reservoirs or flood protection and flood-retaining dams. Dams of this type have been constructed in Austria for various reasons and have shown good behavior during operation. For a better understanding of the load-deformation behavior of this type of dams during construction and impounding, numerical simulations were carried out. The interaction between the thin reinforced concrete core and the dam fill material as well as the influence of fill material properties and other main parameters, such as the roughness of the concrete surface and bedding conditions of the concrete core,on the deformation behavior of dams were examined. The results show that high compressive stress is mainly induced by arching effects in the dam body during construction. During the reservoir impounding, the compressive stresses in the core are reduced significantly while the bending moment in the core footing increases. The results also show that the maximum bending moments occur at the core footing and can be significantly reduced by design improvements. The findings in this study can provide general design recommendations for small dams with a central concrete core as a sealing blanket.

关键词： Embankment dam Concrete diaphragm sealing Numerical analysis Concrete core Structural force

Testing flexible polymer solar cells in near-space

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第5期10卷 105-106页

作者： peter Müller-Buschbaum Department of Physics TUM School of Natural Sciencesand Heinz Maier-Leibnitz-Zentrum(MLZ)Technical University of Munich

Since the big success of the Vanguard1 mission,being the first solar-powered satellite,the use of solar cells in space developed very ***,conventional solar cell technologies for space are based on silicon and GaAs **...

关键词：

Idempotent Completions of Operator Partial Matrices

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 Mathematica Sinica,English Series 1999年第3期15卷 333-346页

作者： Heydar Radjavi peter Rosenthal Department of Mathematics Shanxi Teachers University Linfen 041004 P. R. ChinaDepartment of Mathematics Statistics and Computing Science Dalhousie University Halifax N.S. B3H 3J5 Canada Department of Mathematics University of Toronto Toronto On M5S 1A1 Canada

Necessary and sufficient conditions are obtained for operator partial 2×2 matrices to have an idempotent completion, and all such completions are parametrically represented.

关键词： Hilbert space Operator matrix Idempotent operator

Fluid and Osmotic Pressure Balance and Volume Stabilization in Cells Dedicated to Professor Karl Stark Pister for his 95th birthday

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2021年第12期129卷 1329-1350页

作者： peter M.Pinsky Department of Mechanical Engineering Stanford UniversityStanford94305CAUSA

A fundamental problem for cells with their fragile membranes is the control of their *** primordial solution to this problem is the active transport of ions across the cell membrane to modulate the intracellular osmotic *** this work,a theoretical model of the cellular pump-leak mechanism is proposed within the general framework of linear nonequilibrium *** model is expressed with phenomenological equations that describe passive and active ionic transport across cell membranes,supplemented by an equation for the membrane potential that accounts for the electrogenicity of the ionic *** active ionic transport,the model predicts that the intracellular fluid pressure will be balanced by the osmotic pressure and a new pressure component that arises from the active ionic fluxes.A model for the pump-leak mechanism in an idealized human cell is introduced to demonstrate the applicability of the proposed theory.

关键词： Pump-leak mechanism cell volume regulation active ion transport ion pump membrane transport cell mechanics modified Kedem-Katchalsky equations nonequilibrium thermodynamics phenomenological equations

Imaging tumor hypoxia:Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

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 Innovative Optical Health Sciences 2014年第2期7卷 12-17页

作者： peter Vaupel Armulf Mayer Department of Radioncology and Radiotherapy University Medical Center 55131 MainzGermany

Dedicated to the memory of Professor Briton Chance on the ccasion of his 100th birthday(July24 th,2013),and remembering mary erciting discussions on the orygenation of breast cancer,ontumor hyporia in general and imaging of the orygenation status of malignant *** tissue subvolumes are a hallmark feat ure of solid malignant tumors,relevant for cancertherapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resist ance to several commonly used anticancer *** mech-anisms leading to hypoxia are diverse,may coexist within the same tumor and are commonlygrouped according to the duration of their *** hypoxia is mainly caused by difusionlimitations resulting from enlarged intercapilary distances and adverse difusion geometriesand--to a lsser extent--by hypoxemia,compromised perfusion or long-lasting microregionalfow ***,acute hypoxia preferentilly results from transient disruptions in *** each of these features of the tumor microenvironment can contribute to a criticalreduction of oxy gen availability,the delivery of imaging agents(as well as nutrients and anti-cancer agents)may be compromised or remain unaffected,Thus,a critial appraisal of the ffectsof the various mechanisms leading to hypoxia with regard to the blood-bome delivery of imagingagents is necessary to judge their ability to correctly represent the hypoxic phenotype of solidmalignancies.

关键词： Delivery of imaging agents tumor hypoxia hypoxia subty pes,chronic hypoxia acutehypoxia.

Phytochrome-regulated Gene Expression

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 Integrative Plant Biology 2007年第1期49卷 11-20页

作者： peter H. Quail Department of Plant and Microbial Biology University of Cafifomia Berkeley CA 94720 USA U.S. Department of Agriculture/Agriculture Research Service-Plant Gene Expression Center 800 Buchanan Street Albany CA 94710 LISA

Identification of all genes involved in the phytochrome （phy）-medieted responses of plants to their light environment is an important goal in providing an overall understanding of light-regulated growth end development. This article highlights end integrates the central findings of two recent comprehensive studies in Arabidopsis that have identified the genome-wide set of phy-reguleted genes that respond rapidly to red-light signals upon first exposure of dark-grown seedlings, and have tested the functional relevance to normal seedling photomorphogenesis of an Initial subset of these genes. The data：（a） reveal considerable complexity in the channeling of the light signals through the different phy-femily members （phyA to phyE） to responsive genes; （b） identify a diversity of transcription-factor-encoding genes as major early, if not primary, targets of phy signaling, end, therefore, as potentially important regulators in the transcriptional-network hierarchy; and （c） identify auxin-related genes as the dominant class among rapidly-regulated, hormone-related genes. However, reverse-genetic functional profiling of a selected subset of these genes reveals that only a limited fraction are necessary for optimal phy-induced seedling deetioletion.

关键词： expression profiling phytochrome signaling transcriptional networks microarrays reverse genetics functional profiling transcription factors auxin-related genes

Advanced approaches to high precision MEMS metrology based on interferometric,confocal,and tactile techniques

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2008年第2期4卷 143-146页

作者： peter Lehmann Mahr GmbH 37073 Goettingen Germany

Geometrical features of micro-systems can be determined by either tactile or optical profiling techniques, which show different non-linear transfer characteristics. This has to be considered especially, if the instruments operate close to their physical limitations. Depending on the specific measuring task either point-wise or areal optical measurement may be advantageous. Hence, examples for both approaches are discussed. Furthermore, systematic effects, which are related to the measuring principle have to be taken into account, e.g. if sharp edges or slopes are present on the measuring object. As it is shown, for white-light interferometry these difficulties can be solved by a two-wavelength technique.

关键词：精密度 MEMS 计量方法干涉测量触摸技术

The importance of different forms of prevention in travel medicine

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2010年第1期3卷 74-77页

作者： peter Felkai SOS Hungary Medical Service Szentendrei ut 301 BudapestHungaryH-1039

The Asia-Pacific region is becoming an increasingly popular destination for holidaymakers and business *** the seductive tourist attractions and the growing financial importance of the region,infectious diseases have unfortunately repeatedly caused major epidemics in the *** area includes various geographical situations from high mountains to the subtropical and monsoon forests,dry deserts and *** travel medicine specialist’s task is to decrease the various risk of travel to the *** diseases,extreme temperatures and marine hazards could be almost entirely prevented by primary prevention forms of travel medicine such as vaccination,chemoprophylaxis and pretravel *** are some high-risk groups(e.g.,elderly people,backpackers,families with children,adventure travelers) among the growing number of ***,the increased numbers of such travelers result in a rising incidence of travelrelated illnesses and *** those groups,primary prevention sometimes is not enough. The pretravel medical check up,specialists’ consultations and treatment,as forms of secondary prevention,are also essential in travel *** who suffer from serious illnesses or who have accidents must often be repatriated."State-of-the-art repatriation",as a special form of tertiary prevention of travel medicine will play an important role in the future and is direcdy related to effective travel insurance,which could help in providing good medical care to the patients even far from their *** levels,methods and importance of prevention in travel medicine are discussed in this article.

关键词： Travel medicine Preventive medicine Graduate education Medical assistance Pretravel advice Travel-related illness Prexisting disease Emporiatrics