检索结果-南通市图书馆

Complex Effective Relative Permittivity of s.il s.mples.from the Taunus.Region (Germany)

在线全文

学校读者我要写书评

暂无评论

Journal of Earth s.ience 2010年第6期21卷 961-967页

作者： Katja Lauer Chris.ian Albrecht Chris.ina salat Peter Felix-Hennings.n Ins.itute of s.il s.ience and s.il Cons.rvation Research Centre for BioSystems Land Use and Nutrition (IFZ) Justus-Liebig-University Giessen Department of Underground s.ace for s.orage and Economic Us. Federal Institute for Geosciences and Natural Resources

The mos. important parameter affecting ground-penetrating radar （GPR） meas.rements.is.the complex effective relative permittivity εr^＊,eff becaus. it controls.the propagation velocity and the reflection of GPR puls.s. Knowing εr^＊,eff of s.ils.pas.ed through by electromagnetic waves.increas.s.accuracy in s.il thicknes. and interface identification. Complex effective relative permittivity εr^＊,eff= εr^＊,eff - jεr^＊,effof 25 s.il s.mples.with textures.ranging from loamy s.nd to s.lty clay was.meas.red us.ng the two-electrode parallelplate method. The meas.rements.were conducted at defined water contents.for frequencies.from 1 MHz to 3 GHz. The res.lts.confirm the frequency dependence of εr^＊,eff and s.ow that the dielectric behavior of s.il-water mixtures.is.a function of water content. Applying the experimental data of this.s.udy with predictions.bas.d on the empirical model by Toppet aL （1980）, we find that Topp et aL＇s.curve tends.to underes.imate the real part of εr^＊,eff meas.red. Along with frequency and water content, s.il texture and organic matter affect s.il permittivity. Moreover, the real part of εr^＊,eff increas.s.at higher dry bulk dens.ties. Output from our calibration model enables.us.to predict εr^＊,eff for the s.il s.mples.which were tes.ed under the actual in s.tu s.il water content. This.res.lts.in high accuracy of s.il thicknes. prediction.

关键词： ground-penetrating radar (GPR) complex effective relative permittivity s.il s.mple.

采用混合智能方法评估球墨铸铁摩擦焊接接头的抗拉强度(英文)

在线全文

学校读者我要写书评

暂无评论

Trans.ctions.of Nonferrous.Metals.s.ciety of China 2013年第2期23卷 385-391页

作者： Rados.aw WINICZENKO Robert salat Micha AWTONIUK Department of Production Engineering Warsaw University of Life Sciences Nowoursynowska 164St 02-787 Warsaw Poland

采用混合智能方法评价球墨铸铁的最佳摩擦焊接工艺参数。在自动循环中使用支持向量回归(s.R)、遗传算法(GA)和帝国竞争算法(ICA)优化焊接工艺参数。该方法被用来确定焊接工艺参数,得到了理想的球墨铸铁摩擦焊接抗拉强度。在加热力40kN,... 详细信息

采用混合智能方法评价球墨铸铁的最佳摩擦焊接工艺参数。在自动循环中使用支持向量回归(s.R)、遗传算法(GA)和帝国竞争算法(ICA)优化焊接工艺参数。该方法被用来确定焊接工艺参数,得到了理想的球墨铸铁摩擦焊接抗拉强度。在加热力40kN,加热时间300s.顶锻压力10.12kN条件下,使用s.R加上GA方法得到了最高抗拉强度为256.93MPa。将摩擦焊接样品进行拉伸强度测试,并比较了采用混合智能方法得到的优化值与实验结果。结果表明,混合智能方法可以使ZT14型摩擦焊机拉伸强度从211MPa增加到258MPa。

关键词：摩擦焊接抗拉强度支持向量回归遗传算法经验竞争算法球磨铸铁

弥散张量成像检查大脑淀粉样血管病的白质改变

在线全文

学校读者我要写书评

暂无评论

世界核心医学期刊文摘(神经病学分册) 2006年第12期 40-41页

作者： salat D.H. s.ith E.E. Tuch D.s. 郭俊 Dr.MGH/MIT/HMs.Athinoula A.Martinos.Center for BioMedical Imaging MGH Department of Radiology Charles.own Building 149 United s.ates 13th s. MA 02129-2060

BACKGROUND AND PURPOs.-Cerebral amyloid angiopathy(CAA)repres.nts.β-amyloid depos.tion in the s.all-and medium-s.zed ves.els.of the brain and *** contributes.to altered ves.el function and is.as.ociated with white matter damage,cognitive impairment,and mos. s.lient,hemorrhagic *** us.d diffus.on tens.r imaging to evaluate the anatomic dis.ribution of white matter degeneration in participants.diagnos.d with advanced ***-Diffus.on tens.r imaging was.obtained from 11 participants.diagnos.d with CAA-related intracerebral hemorrhage and 13 matched healthy control *** anis.tropy(FA)and diffus.vity maps.were compared us.ng voxel bas.d t tes. and region-of-interes. ***-FA was.reduced in CAA in temporal white matter and in the s.lenium of the corpus.allos.m(P s.lenium).FA was.marginally increas.d in CAA in the pos.erior limb of the internal caps.le and s.bthalamic gray matter regions.≈7%increas. in s.bthalamic gray).FA changes.were bilateral,remained s.gnificant in clus.er analys.s.controlling for multiple comparis.ns.and did not depend on the hemis.here of the cerebral *** was.not s.bs.antially *** Thes. findings.s.gges. that a pattern of regional brain tis.ue degeneration is.a characteris.ic feature of advanced CAA.

关键词：弥散张量白质髓质大脑淀粉样血管病

全血检测特异性抗结核抗体对结核病快速诊断价值的研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

地方病通报 2005年第3期20卷 50-51页

作者：杨芳玲阿孜古丽.赛来提黎美芝何盛娟刘岩李伟峰屈艳红新疆克拉玛依市疾病预防控制中心新疆克拉玛依834000 新疆克拉玛依市中心医院新疆克拉玛依834000

目的了解全血检测特异性抗结核抗体(LAM-IgG)对结核病快速诊断的价值。方法采受试者手指血20μL用金标试剂盒直接检测LAM-IgG。结果125例涂阳肺结核抗体阳性检出率为92.0%;267例涂阴肺结核抗体阳性检出率为78.3%;94例陈旧性肺结核抗体... 详细信息

目的了解全血检测特异性抗结核抗体(LAM-IgG)对结核病快速诊断的价值。方法采受试者手指血20μL用金标试剂盒直接检测LAM-IgG。结果125例涂阳肺结核抗体阳性检出率为92.0%;267例涂阴肺结核抗体阳性检出率为78.3%;94例陈旧性肺结核抗体阳性检出率为75.5%;36例肺外结核抗体阳性检出率为83.3%;315例非结核抗体阳性检出率为47.6%。本试验灵敏度为82.7%(324/392),特异度为52.4%(165/315)。结论全血快速检测抗结核抗体较血清检测更方便,灵敏度高,但特异度较低,不能作为涂阴肺结核的最终诊断,此项检查可作为涂阴肺结核的辅助诊断和结核可疑者的筛选手段以及肺外结核的诊断指标之一。

关键词：结核抗结核抗体检测金标法