检索结果-南通市图书馆

科学（中文版） 2005年第7期 32-39页

作者： bernard J.Carr steven b.Giddings 王超武星伦敦大学玛丽皇后学院加州大学圣芭芭拉分校

从发明粒子加速器起近80年时间里,物理学家们已经用它们做了些很奇妙的工作,如分裂原子、改变元素、制造反物质以及制造以前从未在自然界中观测到的粒子.不过,幸运的话不久他们就可以迎接一项新的挑战,这将使以前的成果黯然失色.这些加... 详细信息

从发明粒子加速器起近80年时间里,物理学家们已经用它们做了些很奇妙的工作,如分裂原子、改变元素、制造反物质以及制造以前从未在自然界中观测到的粒子.不过,幸运的话不久他们就可以迎接一项新的挑战,这将使以前的成果黯然失色.这些加速器也许会制造出宇宙中最为神秘的物体:黑洞.

关键词：制造量子黑洞粒子加速器物理学家自然界反物质时间原子分裂物体

Detailed description of Division I ice hockey concussions:Findings from the NCAA and Department of Defense CARE Consortium

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 Sport and Health Science 2021年第2期10卷 162-171页

作者： Kathryn L.Van Pelt Jaclyn b.Caccese James T.Eckner Margot Putukian MAlison brooks Kenneth L.Cameron Megan N.Houston Matthew A.Posner Jonathan C.Jackson Gerald T.McGinty Cameron J.Hillis Thomas W.McAllister Michael A.McCrea steven P.broglio Thomas A.buckley Sanders-brown Center on Aging University of KentuckyLexingtonKY 40536-0230USA College of Medicine School of Health and Rehabilitation Sciences The Ohio State UniversityColumbusOH 43210USA Department of Physical Medicine and Rehabilitation Michigan MedicineUniversity of MichiganAnn ArborMI 48108USA University Health Services Princeton UniversityMcCosh Health CenterPrincetonNJ 08544USA Department of Orthopedics and Rehabilitation Department of PediatricsUniversity of Wisconsin School of Medicine and Public HealthMadisonWI 53705-2281USA Keller Army Hospital United States Military AcademyWest PointNY 10996USA th Medical Group United States Air Force AcademyColorado SpringsCO 80840-4000USA Sports Medicine Athletic DepartmentUnited States Air Force AcademyU.S.Air Force AcademyCO 80840-9500USA Novant Health Charlotte Independence Soccer ClubCorneliusNC 28031USA Department of Psychiatry Indiana UniversityIndianapolisIN 46202USA Neurosurgery Medical College of WisconsinMilwaukeeWI 53226USA Michigan Concussion Center University of MichiganAnn ArborMI 48109USA Kinesiology and Applied Physiology University of DelawareNewarkDE 19713USA

Objective:Since concussion is the most common injury in ice hockey,the objective of the current study was to elucidate risk factors,specific mechanisms,and clinical presentations of concussion in men’s and women’s ice ***:Ice hockey players from 5 institutions participating in the Concussion Assessment,Research,and Education Consortium were eligible for the current *** who sustained a concussion outside of this sport were *** were 332(250 males,82 females)athletes who participated in ice hockey,and 47(36 males,11 females)who sustained a ***:Previous concussion(odds ratio(OR)=2.00;95%confidence interval(95%CI):1.02‒3.91)was associated with increased incident concussion odds,while wearing a mouthguard was protective against incident concussion(OR=0.43;95%CI:0.22‒0.85).Overall,concussion mechanisms did not significantly differ between *** were specific differences in how concussions presented clinically across male and female ice hockey players,***(9.09%)were less likely than males(41.67%)to have a delayed symptom onset(p=0.045).Additionally,females took significantly longer to reach asymptomatic(p=0.015)and return-to-play clearance(p=0.005).Within the first 2 weeks post-concussion,86.11%of males reached asymptomatic,while only 45.50%of females reached the same phase of *** males(91.67%)were cleared for return to play within 3 weeks of their concussion,compared to less than half(45.50%)of ***:The current study proposes possible risk factors,mechanisms,and clinical profiles to be validated in future concussions studies with larger female sample *** specific risk factors,concussion mechanisms,and clinical profiles of concussion in collegiate ice hockey may generate ideas for future concussion prevention or intervention studies.

关键词： Concussion risk Injury mechanism Recovery

维普期刊数据库

Evaluation of Control Strategies for Cymbopogon nardus in Grazing Areas of Uganda

在线全文

学校读者我要写书评

暂无评论

Journal of Agricultural Science and Technology(b) 2013年第9期3卷 656-660页

作者： Gilbert steven byenkya Gadi Gumisinza Howard Kasigwa National Agricultural Research Organization (NARO) Mbarara Zonal Agricultural Research and Development Institute Mbarara Uganda National Agricultural Research Organization (NARO) Entebbe Uganda

Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control the weed to allow growth of palatable species. In order to reduce on the drudgery associated with the hand hoe, a trial was set up to evaluate removal with a hand hoe, use of fire and spraying the weed with glyphosate herbicide to control Cymbopogon nardus. Eight treatments associated with the different control strategies were replicated on four sites in the land use system. both manual removal with a hand hoe and spraying with glyphosate herbicide were effective in controlling Cymbopogon nardus with 95% and 92% kill of Cymbopogon tussocks, respectively. The differences between the two control methods were not significant. Plant species biodiversity recovery was faster in the manually controlled plots than in those sprayed with glyphosate, but the number of species was not significantly different. The frequency of occurrence of species was however significantly different with manually controlled plots registering a higher frequency of the species. Fire had no effect as a control strategy, but instead increased the number of tussocks, growth vigour of the re-growth, flowering and hence seed setting. After three seasons, no significant difference was observed in species biodiversity between manual and herbicide control. These results suggest that herbicides could effectively be used to control Cymbopogon nardus to cut on costs and avoid the drudgery normally associated with manual control.

关键词： Cymbopogon control fire glyphosate manual biodiversity Uganda.

Potential of a planarian model to study certain aspects of anti-Parkinsonism drugs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Parkinson's Disease 2013年第3期2卷 70-74页

作者： Robert b. Raffa Jeff Danah Christopher S. Tallarida Carrie Zimmerman Grace Gill steven J. baron Scott M. Rawls Center for Substance Abuse Research and Temple University School of Medicine Philadelphia USA Temple University School of Pharmacy Philadelphia USA

We previously created and investigated a planarian model for the study of drug action, abuse, physical dependence, receptor affinity, the toxicity of heavy metals in wastewater, and seizures. For the present pilot study, we investigated the possibility that this model might be useful for studying certain aspects of drugs used in treatment of Parkinson disease. For the first step, we were interested in finding an in vivo metric for the inhibition of L-DOPA by an inhibitor of DOPA decarboxylase. The direct clinical relevance of the endpoint was of secondary concern during this preliminary phase of model development. Two metrics were explored: L-DOPA-induced inhibition of motility (locomotor velocity) and dopamine-mediated toxicity, which was quantified using a Kaplan-Meier survival curve. L-DOPA produced both dose- and time-related toxicity. The water-soluble DOPA decarboxylase inhibitor benserazide dose-dependently inhibited the effect of L-DOPA, as manifested by a leftward shift in the Kaplan-Meier curve. Additional work was initiated using the more sensitive and a graded metric of spontaneous locomotor velocity. The encouraging results of this pilot study suggest that: 1) planarians contain DOPA decarboxylase or an equivalent enzyme, and 2) the planarian model might be useful for the study of certain aspects of anti-Parkinsonism pharmacotherapy.

关键词： L-DOPA benserazide Planarians

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

超长GIL综合管廊SF6气体泄露模拟研究

现代隧道技术 2020年第3期57卷 91-98,107页

作者：隋心张正维闵绚 DOWNIE steven PADHANI Shahid 赵丽博奥雅纳工程咨询(上海)有限公司上海200031 中国电力科学研究院有限公司武汉430074 Ove Arup&Partners International Limited London B908AE 中南电力设计院有限公司武汉430000

GIL导线中充满SF6气体,由于制造、运输、安装与老化等原因,综合管廊GIL舱存在SF6气体事故泄露的可能性,故应设置专门的监测控制系统与排风系统。文章以武汉谭鑫培路地下综合管廊6.3 km超长GIL舱为案例,结合GIL舱排热通风数据与SF6气体... 详细信息

GIL导线中充满SF6气体,由于制造、运输、安装与老化等原因,综合管廊GIL舱存在SF6气体事故泄露的可能性,故应设置专门的监测控制系统与排风系统。文章以武汉谭鑫培路地下综合管廊6.3 km超长GIL舱为案例,结合GIL舱排热通风数据与SF6气体扩散特性,确定管廊发生气体泄漏后最不利的泄露位置与工况。通过开源计算流体动力学软件OpenFOAM,建立了SF6气体扩散的三维长节段模型与详细短节段模型,并且给出了数值分析流程。在SF6气体典型事故工况中,以排热通风分析的数据作为边界条件进行了分析,从而得到在既有排热通风系统下GIL舱内SF6气体浓度场的变化趋势。分析结果表明,SF6气体主要由常规排热通风系统排出,但是辅助系统能够很大程度上节省排风时间,相关数据可为通风系统与监测系统的优化设计提供建议。数值模拟方法可为其它类型重气在管廊内泄露扩散模拟提供参考。

关键词：综合管廊 GIL舱 SF6气体泄露 OpenFOAM 数值模拟排热排风系统辅助系统监测系统

维普期刊数据库

在线全文

学校读者我要写书评

暂无评论

一些氧化物玻璃中的铬的发光

发光学报 1979年第3期 36-37页

作者： steven A.brawer,Williams b.White,金长清宾夕法尼亚大学材料研究室宾夕法尼亚大学材料研究室

在很多硅酸盐玻璃和其它铬的缔合物中,Cr3+的Dq～1550cm-1的光学吸收和发光发射很象图1所表示的三硅酸钠的光谱。谱带随温度下降有一些移动,但是一直降到液氮温度也未出现新特点。

关键词：能级硅酸钠 Cr 水玻璃钠化合物电子态交叉区域振动态激发态

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

实时UNIX遥测支持系统

遥测遥控 1992年第6期13卷 53-57页

作者： steven b.Crabtree bobby J.Feather 李京

当今,遥测技术的应用需要越来越多的计算功能。低档次和中档次的 RISC 和CISC 计算机正迅速地采用 UNIX 操作系统。在这里,讨论的重点集中于“一个完整的 UNIX 操作系统是否能在一个高速数据传输速率及实时环境中运行?”这个长期存在的... 详细信息

当今,遥测技术的应用需要越来越多的计算功能。低档次和中档次的 RISC 和CISC 计算机正迅速地采用 UNIX 操作系统。在这里,讨论的重点集中于“一个完整的 UNIX 操作系统是否能在一个高速数据传输速率及实时环境中运行?”这个长期存在的问题。

关键词： UNIX 支持系统 CISC 遥测技术预处理器数据传输速率开发环境计算功能数据采集用户接口

维普期刊数据库

Hepatocellular carcinoma diagnosis and treatment: An overview

在线全文

学校读者我要写书评

暂无评论

Liver Research 2020年第4期4卷 159-160页

作者： steven D.Colquhoun Yu-Jui Yvonne Wan Department of Surgery University of California DavisSacramentoCAUSA Department of Pathology and Laboratory Medicine University of California DavisSacramentoCAUSA

For decades,chronic liver disease has remained an increasing global health *** vaccines and antiviral therapies,both hepatitis b and C remain enormous clinical *** steatosis has become a rapidly increasing worldwide concern that can be appropriately characterized as an evolving epidemic.1 Aroundtheworld alcohol consumption is onthe rise,while autoim-mune conditions and environmental toxins all continue contrib-uting to this seemingly universal health *** common denominator of chronic liver disease is progressive hepatic inflam-mation leading to fibrosis and cirrhosis.

关键词： diagnosis clinical treatment

Artificial intelligence-based anomaly detection of the Assen iron deposit in South Africa using remote sensing data from the Landsat-8 Operational Land Imager

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Artificial Intelligence in Geosciences 2022年第1期3卷 71-85页

作者： Glen T.Nwaila steven E.Zhang Julie E.bourdeau Yousef Ghorbani Emmanuel John M.Carranza Wits Mining Institute University of the Witwatersrand1 Jan Smuts Ave.Johannesburg2000South Africa Geological Survey of Canada 601 Booth StreetOttawaOntarioK1A 0E8Canada Department of Civil Environmental and Natural Resources EngineeringLuleåUniversity of TechnologySE–97187LuleåSweden Department of Geology University of the Free State205 Nelson Mandela DrBloemfontein9301South Africa

Most known mineral deposits were discovered by accident using expensive,time-consuming,and knowledgebased methods such as stream sediment geochemical data,diamond drilling,reconnaissance geochemical and geophysical surveys,and/or remote *** years have seen a decrease in the number of newly discovered mineral deposits and a rise in demand for critical raw materials,prompting exploration geologists to seek more efficient and inventive ways for processing various data types at different phases of mineral *** sensing is one of the most sought-after tools for early-phase mineral prospecting because of its broad coverage and low *** sensing images from satellites are publicly available and can be utilised for lithological mapping and mineral *** this study,we extend an artificial intelligence-based,unsupervised anomaly detection method to identify iron deposit occurrence using Landsat-8 Operational Land Imager(OLI)satellite imagery and machine *** novelty in our method includes:(1)knowledge-guided and unsupervised anomaly detection that does not assume any specific anomaly signatures;(2)detection of anomalies occurs only in the variable domain;and(3)a choice of a range of machine learning algorithms to balance between explain-ability and *** new unsupervised method detects anomalies through three successive stages,namely(a)stage Ⅰ–acquisition of satellite imagery,data processing and selection of bands,(b)stage Ⅱ–predictive modelling and anomaly detection,and(c)stage Ⅲ–construction of anomaly maps and *** this study,the new method was tested over the Assen iron deposit in the Transvaal Supergroup(South Africa).It detected both the known areas of the Assen iron deposit and additional deposit occurrence features around the Assen iron mine that were not *** summarise the anomalies in the area,principal component analysis was used on the reconstruction errors across all modelled *** method en

关键词： Anomaly detection Iron deposit Lansat-8 Remote sensing Machine learning Exploration Prospecting