检索结果-南通市图书馆

Neural Regeneration Research 2023年第1期18卷 119-120页

作者： Sara Kelley nelson Perez-Urrutia Rodrigo Morales Department of Neurology University of Texas Health Science Center at HoustonHoustonTXUSA Centro Integrativo de Biologia y Quimica Aplicada(CIBQA) Universidad Bernardo O’HigginsSantiagoChile

Potential causes for the clinical and pathological variability observed in Alzheimer’s disease(AD):AD is an age-related neurodegenerative disorder characterized by the impairment of cognitive functions such as memory,learning,and *** commonly described clinical symptoms are due to particular pathological changes in the brain,including inflammation,synaptic loss,and neuronal *** changes are a consequence of the accumulation of abnormally folded amyloid-β(Aβ)and tau proteins in specific areas of the central nervous *** the progressive aging of the world’s population,the number of people affected by AD is expected to substantially and consistently increase in the coming *** positions AD as one of the main public health challenges in the near future.

关键词： clinical Alzheimer amyloid

The International Commission on the History of Geological Sciences （INHIGEO） Symposium on History of Geophysics

在线全文

学校读者我要写书评

暂无评论

Episodes 2006年第1期29卷 56-58页

作者： Mike Johnston, nelson NEW ZEALAND

The 30th INHIGEO Symposium, with its theme the ＇History of Geophysics＇, was held in the Czech Republic from 2-12 July 2005 and attracted 42 participants from 18 countries. It was hosted by the Geophysical Institute of the Czech Academy of Sciences （GFU） in Prague and was ably organised by Dr Jan Kozak of the Institute. The symposium commenced with a two-day field trip to West Bohemia led by Jiri Babdrek and Ondrej Jaiger of the Czech Geological Survey and PLA Czech Karst respectively. On leaving Prague and its well-bedded Paleozoic sedimentary rocks, the route taken ran northwest across gently rolling Bohemian landscape to the city of Most. On the outskirts of the city a change from Cretaceous sedimentary rocks to ones of Tertiary age was heraided by the appearance of numerous volcanic cones that mark the northeastern end of the Ohre River Rift Zone or Eger Graben.

关键词：地质科学捷克古生代地质工作第三纪

Discharge-Stage Relationship on Urban Streams Evaluated at USGS Gauging Stations,***,Missouri

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 Earth Science 2020年第6期31卷 1133-1141页

作者： Robert E.Criss David L.nelson Department of Earth and Planetary Sciences Washington UniversitySt.Louis MO 63130USA Columbia Cir Pasadena CA 91105USA

Extensive USGS data tables and detailed,1 m2 Li DAR surveys are used to determine the optimal power n that relates discharge(Q)to stage(h*)above channel bottom(ho)at 39 gauging stations on small streams in the ***,Missouri area,all of which have catchments of 0.6 to 220 *** different methodologies are employed to determine both n and ho:(1)optimizing linearity in a plot of Q1/n *** stage(hL)using USGS field measurements at each site;(2)optimizing linearity in a plot of Q1/n *** using USGS rating tables at each site;(3)a mathematical inverse method applied to the same USGS rating tables;(4)use of Li DAR data on channel geometry to determine the power dependences of channel area A and hydraulic radius H on h*,combined with the Manning and rational equations to predict *** these methods,only methods 2 and 3 compare favorably,and these values compare poorly with Method 1 based on field data,and with method 4 based on theoretical and empirical *** Method 4 is predictive,it provides a useful alternative to methods 1–3 that are based on USGS field measurements,which are heavily weighted toward low *** conclude that the apparent values of n in the USGS rating tables are systematically too low for small streams.

关键词： stream gauging Li DAR topography urban flooding discharge hydrology

Crystalline compounds for remediation of rare-earth fission products:A review

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第3期40卷 365-380,I0001页

作者： Saehwa Chong Brian J.Riley Zayne J.nelson Pacific Northwest National Laboratory RichlandWA99352USA

Rare earth(RE)-containing crystals have been investigated as media for the immobilization of RE fission products from nuclear waste *** reprocessing of spent nuclear fuel,fission products including REs,alkalis,and alkaline earths released from the *** viable option to immobilize the RE fission products is to incorporate them into chemically durable crystalline phases in specific waste *** study summarizes the crystal structures and synthesis methods of six RE-containing compounds that have applications in remediation of RE fission *** compounds include oxyapatite(AE_(2)RE_(8)(SiO_(4))_(6)O_(2)),oxychloride(REOCl),borosilicate(RE_(3)BSi_(2)O_(10)),pyrochlore(RE_(2)M_(2)O_(7)),monazite(REPO_(4)),and perovskite(REMO_(3))where AE denotes alkaline earth metals and M denotes transition *** review provides an overview of literature on the usage of these six compounds for immobilizing RE fission products and summarizes different synthesis methods for producing these *** of structural parameters with different REs in each compound are also discussed.

关键词： Rare-earth compounds Nuclear waste forms Crystal structures Synthesis of rare-earth compounds

Modified correlation for minimum fluidization velocity of low-density particles in inverse liquid-solid fluidized beds

在线全文

学校读者我要写书评

暂无评论

Particuology 2022年第12期71卷 56-62页

作者： Michael nelson Saleh Srabet Tian Nan Dominic Pjontek Jesse Zhu Collaborative Innovation Center of Chemical Science and Engineering School of Chemical Engineering and TechnologyTianjin UniversityChina Particle Technology Research Centre Department of Chemical and Biochemical EngineeringWestern UniversityCanada

The minimum fluidization velocity(U_(mf))is a key parameter for the scale-up of inverse liquid-solid flu-idized *** predictions using common correlations were compared against experimental minimum fluidization velocity measurements of low density(28-638 kg/m^(3)),0.80-1.13 mm Styrofoam particles in a fluidized bed with a height of 4.5 m and 0.2 m *** average absolute relative deviation for the predicted minimum fluidization velocity for particles below 300 kg/m^(3) was above 40%using the studied common correlations.A modified Wen and Yu correlation was thus proposed based on novel and past measurements with low-density and small-diameter particles,expanding the range for predicting U_(mf).The new correlation predicted U_(mf) with deviations below 15%for ST028,ST122 and *** modified correlation also improved U_(mf) predictions for comparable particles from a previous study,demonstrating its validity for a larger range of low-density particles.

关键词： Liquid-solid fluidization Inverse fluidization Minimum fluidization velocity Low-density particles

Magnetic Helical Micro-and Nanorobots:Toward Their Biomedical Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2015年第1期1卷 21-26页

作者： Famin Qiu Bradley J.nelson Institute of Robotics and Intelligent Systems(IRIS) ETH Zurich

Magnetic helical micro- and nanorobots can perform 3D navigation in various liquids with a sub- micrometer precision under low-strength rotating magnetic fields （〈 10 rer）. Since magnetic fields with low strengths are harmless to cells and tissues, magnetic helical micro/ nanorobots are promising tools for biomedical applications, such as minimally invasive surgery, cell manipulation and analysis, and targeted therapy. This review provides general information on magnetic helical micro/nanorobots, including their fabrication, motion control, and further functionalization for biomedical applications.

关键词： magnetic helical micro/nanorobots mobilemicro/nanorobots artificial bacterial flagella (ABFs) functionalization biomedical applications

Current issues in endoscope reprocessing and infection control during gastrointestinal endoscopy

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 2006年第25期12卷 3953-3964页

作者： Douglas B nelson Lawrence F Muscarella Staff Physician in Gastroenterology Minneapolis VA Medical Center University of MinnesotaMinneapolisMN 55417United States Director Research and Development ChiefInfection ControlCustom UltrasonicsInc

The purpose of this article is to review the evidence regarding transmission of infection during gastrointestinal endoscopy, factors important in endoscope reprocessing and infection control, areas to focus on to impr... 详细信息

关键词： Endoscopy Infection Disinfection Reprocessing Infection control

A Preliminary Feasibility Study on Wind Resource and Assessment of a Novel Low Speed Wind Turbine for Application in Africa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2022年第3期119卷 997-1015页

作者： Kehinde Adeyeye nelson Ijumba Jonathan Colton African Centre of Excellence Energy for Sustainable DevelopmentUniversity of RwandaKigaliRwanda School of Engineering University of KwaZulu NatalDurbanSouth Africa George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaUSA

This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in *** wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and *** a result,only a few countries in Africa have been able to include wind energy in their energy *** this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in *** performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African *** research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is *** show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.

关键词： Wind energy conventional wind turbines ferris wheel wind turbine energy access sub-sahara africa wind speed

Effects of building aspect ratio,diurnal heating scenario,and wind speed on reactive pollutant dispersion in urban street canyons

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 Environmental Sciences 2012年第12期24卷 2091-2103页

作者： nelson Y.O.Tong Dennis Y.C.Leung Department of Mechanical Engineering The University of Hong Kong

A photochemistry coupled computational fluid dynamics （CFD） based numerical model has been developed to model the reactive pollutant dispersion within urban street canyons, particularly integrating the interrelationship among diurnal heating scenario （solar radiation affections in nighttime, daytime, and sun-rise/set）, wind speed, building aspect ratio （building-height-to-street-width）, and dispersion of reactive gases, specifically nitric oxide （NO）, nitrogen dioxide （NO2） and ozone （O3） such that a higher standard of air quality in metropolitan cities can be achieved. Validation has been done with both experimental and numerical results on flow and temperature fields in a street canyon with bottom heating, which justifies the accuracy of the current model. The model was applied to idealized street canyons of different aspect ratios from 0.5 to 8 with two different ambient wind speeds under different diurnal heating scenarios to estimate the influences of different aforementioned parameters on the chemical evolution of NO, NO2 and 03. Detailed analyses of vertical profiles of pollutant concentrations showed that different diurnal heating scenarios could substantially affect the reactive gases exchange between the street canyon and air aloft, followed by respective dispersion and reaction. Higher building aspect ratio and stronger ambient wind speed were revealed to be, in general, responsible for enhanced entrainment of 03 concentrations into the street canyons along windward walls under all diurnal heating scenarios. Comparatively, particular attention can be paid on the windward wall heating and nighttime uniform surface heating scenarios.

关键词： photochemistry reactive pollutant dispersion building aspect ratio diurnal heating scenario wind speed urban streetcanyon

Vocal repertoire of the New Zealand kea parrot Nestor notabilis

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2012年第5期58卷 727-740页

作者： Raoul SCHWING Stuart PARSONS Ximena J. nelson School of Biological Sciences University of Auckland Private Bag 92019 Auckland New Zealand School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch New Zealand

The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com- munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand＇s Southern Alps. Based on audio and visual spectrographic differences, these calls were categorised into seven distinct call types： the non-oscillating ＇screech＇ contact call and ＇mew＇; and the oscillating ＇trill＇, ＇chatter＇, ＇warble＇ and ＇whistle＇; and a hybrid ＇screech-trill＇. Most of these calls contained aspects that were individually unique, in addition to potentially encoding for an individual＇s sex and age. Additionally, for each recording, the sender＇s previous and next calls were noted, as well as any response given by conspecifics. We found that the previous and next calls made by the sender were most often of the same type, and that the next most likely pre- ceding and/or following call type was the screech call, a contact call which sounds like the ＇kee-ah＇ from which the bird＇s name derives. As a social bird capable of covering large distances over visually obstructive terrain, long distance contact calls may be of considerable importance for social cohesion. Contact calls allow kea to locate conspecifics and congregate in temporary groups for social activities. The most likely response to any given call was a screech, usually followed by the same type of call as the ini- tial call made by the sender, although responses differed depending on the age of the caller. The exception was the warble, the kea＇s play call, to which the most likely response was another warble. Being the most common call type, as well as the default response to another call, it appears that the ＇contagious＇ screech contact call plays a central role in kea vocal communication and social cohesion [Current Zoology 58 （5）： 727-740, 2012].

关键词： Acoustic signals Communication Kea Psittacidae Social behaviour Habitat