检索结果-南通市图书馆

Soundscapes and the sense of hearing of fishes

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 2009年第1期4卷 26-32页

作者： richard FAY Parmly Hearing Institute Loyola University ChicagoChicagoUSA

Underwater soundscapes have probably played an important role in the adaptation of ears and auditory systems of fishes throughout evolutionary time,and for all *** sounds probably contain important information about the environment and about most objects and events that confront the receiving fish so that appropriate be-havior is *** example,the sounds from reefs appear to be used by at least some fishes for their orientation and *** sorts of environmental sounds should be considered much like“acoustic daylight,”that continuously bathes all environments and contain information that all organisms can potentially use to form a sort of image of the *** present,however,we are generally ignorant of the nature of ambient sound fields impinging on fishes,and the adaptive value of processing these fields to resolve the multiple sources of *** field has focused almost exclusively on the adaptive value of processing species-specific communication sounds,and has not considered the informational value of ambient“noise.”Since all fishes can detect and process acoustic particle motion,including the directional characteristics of this motion,underwater sound fields are potentially more complex and information-rich than terrestrial acoustic *** capacities of one fish species(goldfish)to receive and make use of such sound source information have been demonstrated(sound source seg-regation and auditory scene analysis),and it is suggested that all vertebrate species have this capacity.A call is made to better understand underwater soundscapes,and the associated behaviors they determine in fishes.

关键词： acoustic daylight auditory scene analysis soundscape sound source segregation.

Combining scanning tunneling microscope (STM) imaging and local manipulation to probe the high dose oxidation structure of the Si(111)-7×7 surface

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2020年第1期13卷 145-150页

作者： Dogan Kaya richard J.Cobley richard E.Palmer Department of Electronics and Automation Vocational School of AdanaCukurova University01160CukurovaAdanaTurkey Nanoscale Physics Research Laboratory School of Physics and AstronomyUniversity of BirminghamEdgbastonBirminghamB152TTUK College of Engineering Swansea UniversityBay CampusFabian WaySwanseaSA18ENUK

Understanding the atomistic formation of oxide layers on semiconductors is important for thin film fabrication,scaling down conventional devices and for the integration of emerging research ***,the initial oxidation of Si(111)is studied using the scanning tunneling *** to the complete saturation of the silicon surface with oxygen,we are able to probe the atomic nature of the oxide layer *** establish the threshold for local manipulation of inserted oxygen sites to be+3.8 *** by combining imaging with local atomic manipulation are we able to determine whether inserted oxygen exists beneath surface-bonded oxygen sites and differentiate between sites that have one and more than one oxygen atom inserted beneath the *** to the creation of the thin oxide film we observe a flip in the manipulation rates of inserted oxygen sites consistent with more oxygen inserting beneath the silicon surface.

关键词： scanning tunneling microscopy(STM) local manipulation Si(111) oxidation

Landmarks in the application of electrical tomography in particle science and technology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2010年第6期8卷 493-497页

作者： richard A.Williams Institute of Particle Science and Engineering School of ProcessEnvironmental and Materials EngineeringUniversity of LeedsLeedsWest YorkshireLS2 9JTUK

Selected milestones in the development and use of electrical tomography in powder conveying, slurry processing and multi-phase flow are highlighted. The ability to map concentration in opaque mixtures under process-realistic conditions was a major innovation for the method and has had far reaching implications. Subsequent developments have enabled velocity information to be abstracted resulting in the ability to measure component flux and motion.

关键词： Computational fluid dynamics Fault condition and maloperation Flow measurement Flow regime identification Particle concentration Process control Process safety

Radiocarbon calibration:The next generation

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2021年第3期64卷 507-510页

作者： richard A STAFF Ruiliang LIU Scottish Universities Environmental Research Centre(SUERC) University of GlasgowEast KilbrideG750QFUK School of Archaeology University of OxfordOxfordOX13TGUK

The discovery of the radiocarbon(14C)dating technique in the mid-twentieth century by Willard Libby and colleagues(Libby et al.,1949)revolutionised such fields as archaeology and palaeoclimatology that require robust chronological information to inform their *** sample yielding sufficient quantities of carbon could be dated in this manner,with the older age limit of the method(currently circa 50 to 60 thousand years ago)having been pushed back significantly since its inception.

关键词： dating dated carbon

Effects of taxon sampling on molecular dating for within-genus divergence events,when deep fossils are used for calibration

在线全文

学校读者我要写书评

暂无评论

Journal of Systematics and Evolution 2009年第5期47卷 383-401页

作者： richard I.MILNE Institute of Molecular Plant Sciences The University of Edinburgh

A universal method of molecular dating that can be applied to all families and genera regardless of their fossil records,or lack thereof,is highly desirable.A possible method for eudicots is to use a large phylogeny calibrated using deep fossils including tricolpate pollen as a fixed(124 mya) calibration *** method was used to calculate node ages within three species-poor disjunct basal eudicot genera,Caulophyllum,Podophyllum and Pachysandra,and sensitivity of these ages to effects such as taxon sampling were then *** deleting from one to three accessions related to each genus in 112 different combinations,a confidence range describing variation due only to taxon sampling was *** for Caulophyllum,Podophyllum and Pachysandra were 8.4-10.6,7.6-20.0,and 17.6-25.0 mya,***,the confidence ranges calculated using bootstrapping were much wider,at 3-19,0-32 and 11-32 mya,***,deleting 10 adjacent taxa had a large effect in Pachysandra only,indicating that undersampling effects are significant among *** to sampling density in neighboring clades,or to the position of the fixed fossil calibration point had small to negligible ***-parametric rate smoothing was more sensitive to taxon sampling effects than was penalized *** wide range for Podophyllum,compared to the other two genera,was probably due to a high degree of rate heterogeneity within this *** ranges calculated by this method could be narrowed by sampling more individuals within the genus of interest,and by sequencing multiple DNA regions from all species in the phylogeny.

关键词： basal eudicots fossil calibration molecular dating North America-East Asia disjunction taxon sampling Tertiary relict tricolpate pollen.

DNA barcoding of Pedicularis L.(Orobanchaceae):Evaluating four universal barcode loci in a large and hemiparasitic genus

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systematics and Evolution 2011年第5期49卷 425-437页

作者： richard H.REE Department of Botany Field Museum of Natural History

One application of DNA barcoding is species identification based on sequences of a short and standardized DNA *** plants,various DNA regions,alone or in combination,have been proposed and investigated,but consensus on a universal plant barcode remains *** this study,we tested the utility of four candidate barcoding regions(rbcL,matK,trnH-psbA,and internal transcribed spacer(ITS)) as DNA barcodes for discriminating species in a large and hemiparasitic genus Pedicularis(Orobanchaceae).Amplification and sequencing was successful using single primer pairs for rbcL,trnH-psbA,and ITS,whereas two primer pairs were required for *** of sequence divergence commonly showed a "barcoding gap",that is,a bimodal frequency distribution of pairwise distances representing genetic diversity within and between species,*** primer universality,ease of amplification and sequencing,and performance in discriminating species,we found the most effective single-region barcode for Pedicularis to be ITS,and the most effective two-region barcode to be rbcL + *** discriminated at least 78% of the 88 species and correctly identified at least 89% of the sequences in our sample,and were effective in placing unidentified samples in known species *** results suggest that DNA barcoding has the potential to aid taxonomic research in Pedicularis,a species-rich cosmopolitan clade much in need of revision,as well as ecological studies in its center of diversity,the Hengduan Mountains region of China.

关键词： DNA barcode Hengduan Mountains region ITS Pedicularis rbcL species identification.

Characterization of mudrocks:a practical application of advanced laboratory testing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第1期12卷 1-14页

作者： richard J.JARDINE Department of Civil and Environmental Engineering Imperial College London

An integrated approach to geomaterial characterization is advocated that combines geology, in-situ testing, fabric studies, routine index experiments and advanced laboratory testing. It is shown that advanced laboratory testing can explore features such as kinematic yielding and anisotropy in stiffness or shear strength that would otherwise be impossible to quantify. A detailed study performed in London clay at the new Heathrow Terminal 5 site is used to illustrate the arguments made. It is shown that the London clay has strong anisotropy in stiffness, is highly non-linear over the strain range of engineering interest, has markedly anisotropic shear strength characteristics and exhibits a pronounced degree of brittleness. These features can impact significantly on the practical design and analysis of civil engineering works including shallow and deep foundations, tunnels and excavations, and the stability of slopes.

关键词： Mudrock Fabric Anisotropy Hollow cylinder tests

Lab experiments on the innovative rapid thick strip casting process

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 391-398页

作者： richard Nagy Dieter Senk Department of Ferrous Metallurgy IEHK RWTH Aachen UniversityAachen 52056Germany

Rapid thick strip casting （RTSC） by Anton Hulek, Inventmetall, is an innovative concept for the production of hot strips with a final as-cast thickness of about 25 mm before rolling. The innovation of the mechanism consists in a vertical mould performing a caterpillar motion. This moving mould has an unconventional parallelogram-shaped cross-section. The conventional rectangular shape is formed in the shaping machine, which is placed straight below the mould. Further elements of the technology are state-of-the-art. For the investigation of this new casting system theoretical calculations were complemented with practical experiments. The investigation focused mainly on two key aspects： the characteristics of the mould and the shaping process. For the practical analysis a static mould with three pairs of elements in laboratory scale was developed and commissioned by the Dept. of Ferrous Metallurgy @ RWTH Aachen University. The shaping experiments were carried out in model scale with two different materials and in variable boundary conditions. The results of these experiments delivered important mechanical as well as thermal informations about the casting system.

关键词： continuous casting rapid solidification strip metal moulds near-net-shape casting

Critical questions in development of targeted nanoparticle therapeutics

在线全文

学校读者我要写书评

暂无评论

Regenerative Biomaterials 2016年第2期3卷 143-147页

作者： richard Korsmeyer Pharmaceutical Sciences Pfizer Worldwide R&DGrotonCT 06340USA

One of the fourteen Grand Challenges for Engineering articulated by the US National Academy of Engineering is‘Engineer Better Medicines’.Although there are many ways that better medicines could be engineered,one of the most promising ideas is to improve our ability to deliver the therapeutic molecule more precisely to the desired *** conventional drug delivery methods(oral absorption,intravenous infusion etc.)result in systemic exposure to the therapeutic molecule,which places severe constraints on the types of molecules that can be used.A molecule administered by systemic delivery must be effective at low concentrations in the target tissue,yet safe everywhere else in the *** drug carriers could be developed to deliver therapeutic molecules selectively to the desired target,it should be possible to greatly improve safety and efficacy of ***(and related nanostructures,such as liposomes,nanoemulsions,micelles and dendrimers)are an attractive drug carrier concept because they can be made from a variety of materials engineered to have properties that allow loading and precise delivery of bound therapeutic *** field of targeted nanoparticles has been extraordinarily active in the academic realm,with thousands of articles published over the last few *** of these publications seem to demonstrate very promising results in in vitro studies and even in animal *** addition,a handful of human clinical trials are in ***,the biopharmaceutical industry has been relatively slow to make major investments in targeted nanoparticle development programs,despite a clear desire to introduce innovative new therapies to the *** is the reason for such caution?Some degree of caution is no doubt due to the use of novel materials and the unproven nature of targeted nanoparticle technology,but many other unproven technologies have generated intense interest at various *** believe that the major barrier to the exploration

关键词： nanoparticles targeting biodistribution manufacturing