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A STUDY ON EM SCATTERING OF A TWO-DIMENSIONAL INHOMOGENEOUS STRUCTURE BURIED IN STRATIFIED MEDIA
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作者 Wang Weiyan Zhang Shourong(Institute of Electronics, Academia Sinica, Beijing 100080) 《Journal of Electronics(China)》 1997年第1期90-96,共7页
The TM-polarized electromagnetic scattering problem of a two-dimensional inho-mogeneous structure buried in lossy stratified media is presented. Analysis work consists of two parts mainly, derivation of the Green’s f... The TM-polarized electromagnetic scattering problem of a two-dimensional inho-mogeneous structure buried in lossy stratified media is presented. Analysis work consists of two parts mainly, derivation of the Green’s function of a filament buried in lossy stratified media and constitution of the electric field integral equation of the equivalent current caused by the differences between the inhomogeneities and the stratified media. Based on these works, illustrative numerical results are given to model inhomogeneous underground tubes in lossy stratified media, and to describe the scattering field affected by different factors such as permittivity distribution, dimension, and buried depth of the inhomogeneities and so on. 展开更多
关键词 EM SCATTERING STRATIFIED media 2-d inhomogenEITY BURIED OBJECT
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TWO-DIMENSIONAL VECTOR RADIATIVE TRANSFER EQUATION FOR INHOMOGENEOUS SCATTERING MEDIA
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作者 金亚秋 《Chinese Science Bulletin》 SCIE EI CAS 1991年第1期29-32,共4页
In the last decade or so the radiative transfer (RT) theory has been widely applied to the numerical simulations of scattering and thermal emission in both passive and active remote sensing. However, the model of scat... In the last decade or so the radiative transfer (RT) theory has been widely applied to the numerical simulations of scattering and thermal emission in both passive and active remote sensing. However, the model of scattering media has been largely restrictive to the horizontallyinfinite, stratified random media where the scatterers are homogeneously and randomly distributed. Correspondingly, the RT equation is one-dimensional (1-D). Recent 展开更多
关键词 inhomogeneous SCATTERING media 2-d RADIATIVE transfer REMOTE sensing.
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糖尿病不同病程及血糖控制水平对颈动脉结构及功能的影响
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作者 武彧 吕清 +5 位作者 谢明星 程新耀 刘曼薇 谢满英 章子铭 丁尚伟 《中国介入影像与治疗学》 CSCD 2014年第7期446-449,共4页
目的探讨2型糖尿病(T2DM)不同血糖控制水平及患病时间对颈动脉内-中膜形态及功能的影响。方法选取T2DM患者58例,分为3组:病程≤2年为初发组(26例),将病程>2年者根据空腹血糖(FPG)水平分为FPG正常组(FPG<7.1mmol/L,10例)和FPG升高... 目的探讨2型糖尿病(T2DM)不同血糖控制水平及患病时间对颈动脉内-中膜形态及功能的影响。方法选取T2DM患者58例,分为3组:病程≤2年为初发组(26例),将病程>2年者根据空腹血糖(FPG)水平分为FPG正常组(FPG<7.1mmol/L,10例)和FPG升高组(FPG≥7.1mmol/L,22例)。另设正常对照组47名。测量双侧颈动脉内-中膜非均匀度(IMI)、颈动脉内-中膜平均厚度(IMTmean),以血管回声追踪技术测量双侧颈动脉内-中膜僵硬度(β)、脉搏波传导速度(PWV),并分析IMI与年龄、血糖水平、病程、血脂及动脉弹性的关系。结果与正常对照组相比,T2DM患者β、PWV、IMI的对数[Ln(β)]、Ln(PWV)、Ln(IMI)]均升高;FPG正常及升高组IMTmean的对数[Ln(IMTmean)]亦增高;FPG升高组较FPG正常组及DM初发组Ln(β)及Ln(PWV)均升高(P均<0.05)。颈动脉IMI与病程、年龄、FPG、TG、SBP呈正相关(r=0.620、0.428、0.303、0.228、0.208,P均<0.05)。结论作为反映血管结构的指标,IMI在早期筛查T2DM、血管结构变化中优于IMT。β、IMI及IMT相结合,可以全面评估在高血糖或合并其他危险因素作用下动脉病变的发生发展程度。 展开更多
关键词 糖尿病 2 颈动脉 弹性 内-中膜厚度 内-中膜非均匀度
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平面分层媒质中二维非均匀结构电磁散射的研究
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作者 王卫延 张守融 《电子科学学刊》 CSCD 1997年第1期105-111,共7页
本文研究埋藏在平面分层媒质中的二维非均匀结构的电磁散射分析方法和散射特性。在推导平面分层介质中电流丝辐射的Green函数的基础上,建立非均匀结构相对于分层媒质的等效电流所产生散射场的电场积分方程,进而在离散的条件下求解。利... 本文研究埋藏在平面分层媒质中的二维非均匀结构的电磁散射分析方法和散射特性。在推导平面分层介质中电流丝辐射的Green函数的基础上,建立非均匀结构相对于分层媒质的等效电流所产生散射场的电场积分方程,进而在离散的条件下求解。利用文中提出的方法,对于不同介质目标的散射进行了计算,并比较了埋藏深度、周围介质、分层结构等因素对埋藏目标散射特性的影响。 展开更多
关键词 电磁散射 平面分层介质 二维非均匀结构
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地震折射波资料解释中射线方法应用的进一步探讨 被引量:1
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作者 李平 《防灾减灾学报》 1992年第4期41-48,共8页
开鲁陆家堡凹陷内断裂发育、构造复杂,垂直于构造走向跨度30km,凹陷边缘和凹陷内古生界基底顶板埋深分别为1km和5km,在此开展了基底折射波地震勘探。在已知资料基础上,我们用多段倾斜单界面折射波正演理论计算作指导,设计了野外试验和... 开鲁陆家堡凹陷内断裂发育、构造复杂,垂直于构造走向跨度30km,凹陷边缘和凹陷内古生界基底顶板埋深分别为1km和5km,在此开展了基底折射波地震勘探。在已知资料基础上,我们用多段倾斜单界面折射波正演理论计算作指导,设计了野外试验和初步的生产观测系统,t_0和差异时距曲线解释方法对于应用于如此复杂的构造地区其准确性和精度受到了限制。因此,我们在解释方法上试做了如下工作:①多段倾斜单界面折射波理论正演走时拟合,给出较有益的反演解释结果;②二维非均匀介质中射线追踪解释方法,提供准确的射线途径给出基底面上下详尽的更为符合实际的二维速度分布信息。 展开更多
关键词 折射波地震勘探 正演和反演 二维非均匀介质 射线追踪
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In Vitro Study of Callogenesis and Regeneration Potential of Elite Wheat (Triticum aestivum L.) Cultivars
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作者 Muhammad Iqbal Naveed Iqbal Raja +7 位作者 Saira Asif Noshin Ilyas Mubashir Hussain Farhat Yasmeen Muhammad Ejaz Muhammad Asim Sultan Sumaira Aslam Hina Javed 《American Journal of Plant Sciences》 2016年第17期2515-2526,共13页
The potential for biotechnological applications in crop improvement programs requires identifying genotypes that allow cell/tissue culture with predictable plant regeneration. In the past, many genotypes of wheat (Tri... The potential for biotechnological applications in crop improvement programs requires identifying genotypes that allow cell/tissue culture with predictable plant regeneration. In the past, many genotypes of wheat (Triticum aestivum L.) have been examined for potential use in tissue culture studies. The present research work has also been designed to study in vitro callogenesis expression and regeneration potential of wheat cultivars under controlled laboratory conditions. Seeds of four elite commercial high yielding cultivars of wheat namely: NARC-2011, AAS-2011, PAK-2013 and GAL-2013, were collected from the Crop Science Institute National Agricultural Research Center (CSI-NARC) Islamabad, as the source of plant material for in vitro studies. The seeds were surface sterilized in 10% sodium hypochlorite solutions for 10 minutes with continuous shaking under laminar air flow hood. After that seeds were placed on MS (Murashige & Skoog, 1962) based callus induction and regeneration medium with various concentrations of 2, 4-D and BAP in separate test tubes. Maximum callus induction frequency of 90% for Pak-13 and AAS-11, followed by 87% and 83% for Gla-13 and NARC-11, respectively, was recorded at 4 mg/l and 6 mg/l of 2, 4-D. Similarly, maximum regeneration of 90% for AAS-11 and Pak-13, followed by 80% and 87% for NARC-11 and Gla-13 respectively, was recorded on MS basal medium containing 1.5 mg/l of BAP. An increasing trend in regeneration from 0.5 to 1.5 mg/l of BAP was observed but it gradually decreased with increasing concentration of BAP from 1.5 mg/l for all wheat cultivars. The callus formed under light was golden brown, dry nodule and smooth compact and less embryogenic while under dark conditions, it was white to yellowish white, dry nodule and compact and more embryogenic. Best results for callus induction and regeneration were obtained at temperature (24°C ± 1°C) for all wheat cultivars. 展开更多
关键词 Tissue Culture MS medium 2 4-d and BAP Callus Induction REGENERATION WHEAT
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