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3篇 您的检索式:作者名="David M.Smith"
    题名 作者 年代 出处 被引量
1History and evaluation of national-scale geochemical data sets for the United States显示文摘六国家规模,或近国家规模,为土壤的 geochemical 数据集合或溪流沉积为美国存在。这些最早,这里称为 Shacklette 数据集合,被从 1961 ~ 1975 进行的一个美国地质的调查(USGS ) 工程产生。这个工程使用了在整个有共同边界的美国在 1323 个地点作为采样媒介从大约 20 厘米的深度收集的土壤美国能源部的国家的铀资源评估 Hydrogeochemical 和流沉积侦察( NURE-HSSR )程序从 1975~1984 被进行并且收集了任何一个流沉积,在在有共同边界的美国和阿拉斯加的超过 378,000 个地点的湖沉积,或土壤。取样的区域代表了大约 65% 国家。从 1978 ~ 1982,自然资源保存服务(NRCS ) 在这个数据设置了的有共同边界的美国的主要成长庄稼的区域以内在地点从多重土壤地平线收集了样品包含超过 3000 件样品的分析。国家 Geochemical 调查,从 1997 ~ 2009 进行,把 NURE-HSSR 档案的样品的一个子集用作它的起点然后首先收集了溪流沉积的一个 USGS 工程与偶尔的土壤,在没被 NURE-HSSR 盖住的美国的部分编程序。这个数据集合为超过 70,000 件样品包含化学分析。与墨西哥地质的调查和加拿大的地质的调查合作, USGS 在 2007 为北美的土壤 Geochemical 风景工程开始了土壤采样。在在美国的超过 4800 个地点的三根地平线或深度的采样在 2010 被完成,并且化学分析当前是进行中的。NRCS 在 1990 年代开始了一个工程全部从选择 pedons 分析各种各样的土壤地平线这个数据设置了的美国当前从超过 1400 个地点包含数据。这份报纸(1 ) 以它的目的,样品收集协议,和分析方法讨论每个数据集合;并且(2 ) 为印射的国家规模的 geochemical 作为一个国家规模的 geochemical 数据库和它的实用性以它的适当评估每个数据集合。David B.Smith Steven M.Smith John D.Horton 2013Geoscience Frontiers2013,4,2:8
2Tailoring spin mixtures by ion-enhanced Maxwell magnetic coupling in colortunable organic electroluminescent devices显示文摘In this work,we show that the spin dynamics of excitons can be dramatically altered by Maxwell magnetic field coupling,together with an ion-enhanced,low-internal-splitting-energy organic semiconducting emitter.By employing a unique,alternating current(AC)-driven organic electroluminescent(OEL)device architecture that optimizes this magnetic field coupling,almost complete control over the singlet-to-triplet ratio(from fluorescent to phosphorescent emission in a single device)is realized.We attribute this spin population control to magnetically sensitive polaron–spin pair intersystem crossings(ISCs)that can be directly manipulated through external driving conditions.As an illustration of the utility of this approach to spin-tailoring,we demonstrate a simple hybrid(double-layer)fluorescence–phosphorescence(F–P)device using a polyfluorene-based emitter with a strong external Zeeman effect and ion-induced long carrier diffusion.Remarkable control over de-excitation pathways is achieved by controlling the device-driving frequency,resulting in complete emission blue–red color tunability.Picosecond photoluminescence(PL)spectroscopy directly confirms that this color control derives from the magnetic manipulation of the singlet-totriplet ratios.These results may pave the way to far more exotic organic devices with magnetic-field-coupled organic systems that are poised to usher in an era of dynamic spintronics at room temperature.Junwei Xu Yue Cui Gregory M.Smith Peiyun Li Chaochao Dun Linqi Shao Yang Guo Hongzhi Wang Yonghua Chen David L.Carroll 2018Light(Science & Applications)2018,7,1:2
3Water balloon-induced orbital fracture in an aviator显示文摘Background:Orbital fractures are common injuries found in facial trauma.Typical etiologies of orbital fractures include motor vehicle collisions and assault.We report the case of a 32-year-old male who suffered an orbital fracture from a water balloon.Additionally,we describe the aeromedical complications that may result from this injury.Finally,we attempt to answer the question of when a patient may return to flying after sustaining such an injury through review of the literature.Case presentation:A 32-year-old male pilot with the United States Air Force was at an outdoor event with his unit when he was struck with a water balloon launched from a sling shot into his left orbit.Shortly afterwards,he had an onset of subcutaneous emphysema and was escorted to a nearby Emergency Department.Computed tomography identified an orbital fracture with associated orbital and subcutaneous emphysema.The patient was evaluated by a plastic surgeon and was determined not to be a surgical candidate.Four weeks later,he returned to flying status.Conclusions:Water balloons are thought to be safe and harmless toys.However,when coupled with sling shots,water balloons can become formidable projectiles capable of significant orbital injury including orbital fractures.These injuries are concerning to aviators,as the most common sites for fractures of the orbit are the thin ethmoid and maxillary bones adjacent to the sinuses.At altitude,gases in the sinuses may expand and enter the orbit through these fractures,which may suddenly incapacitate the flyer.It is important for flight surgeons to identify and assess these individuals to determine suitability for flying.Timothy E.Holland David M.Smith Guy N.Gibson Jared G.Brinkerhoff 2020Military Medical Research2020,7,2:0
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