色散特性对毫米波频率步进雷达影响的研究

对影响毫米波频率步进雷达分辨率的主要因素进行了分析。除目标速度以外,为毫米波频率步进雷达提供频率信号的频率源的色散特性也会对雷达分辨率造成恶化影响。微波频段上的色散特性会被搬移到毫米波频段,导致毫米波发射信号和本振信号的初始相位差不为常数,对雷达系统尤其是距离分辨率造成严重影响。仿真结果与实验结果一致。为了抵消色散特性对雷达分辨率的恶化影响,可以通过对色散特性的补偿来实现。色散特性补偿的方法被应用到实现W波段频率步进频率源的设计中,满足了0.45m距离分辨率的要求。     

Z2—商的秩为2的超椭圆曲面的斜率

设S是一般型的超椭圆曲面，f:S→C是亏格g的超椭圆纤维化。我们证明了如果S的极大挠2商为Z2^2那么λ（f)≥4，等号成立当且仅当S的奇异性指数除s3外全部为0。     

基于相空间形状分析预测房颤终止

识别和描述房颤有可能自发终止还是持续,不仅可以更好地了解心律不齐发作和终止的机制,还可以更有效地治疗持续房颤。本文从非线性角度提取房颤信号特征并预测其能否自发终止。先重建心电信号的相空间,获取相空间中指定庞加莱截面上的点,然后基于形状分析提取刻画庞加莱面上相似点对相对数量的参数ρ,最后基于ρ来分类非终止房颤和可终止房颤。实验研究了一个由Holter心电信号组成的包括训练集和测试集的房颤数据库,结果表明:本文提出的特征参数ρ可正确分类90%的测试集。可见,该方法能从Holter心电信号有效地预测房颤的自发终止。     

高斯定理的理解与应用

文章论述了高斯定理源于库仑定律，依赖于场强叠加原理，场强通量与场线通量均遵从高斯定理；高斯面上的场强是其内外所考虑的电荷产生的合场强；构建体系高斯面，局部高斯面求解场强问题。     

Estimating Contaminant Dose for Intermittent Dermal Contact: Model Development, Testing, and Application

Assessments of aggregate exposure to pesticides and other surface contamination in residential environments are often driven by assumptions about dermal contacts. Accurately predicting cumulative doses from realistic skin contact scenarios requires characterization of exposure scenarios, skin surface loading and unloading rates, and contaminant movement through the epidermis. In this article we (1) develop and test a finite-difference model of contaminant transport through the epidermis; (2) develop archetypal exposure scenarios based on behavioral data to estimate characteristic loading and unloading rates; and (3) quantify 24-hour accumulation below the epidermis by applying a Monte Carlo simulation of these archetypal exposure scenarios. The numerical model, called Transient Transport through the epiDERMis (TTDERM), allows us to account for variable exposure times and time between exposures, temporal and spatial variations in skin and compound properties, and uncertainty in model parameters. Using TTDERM we investigate the use of a macro-activity parameter (cumulative contact time) for predicting daily (24-hour) integrated uptake of pesticides during complex exposure scenarios. For characteristic child behaviors and hand loading and unloading rates, we find that a power law represents the relationship between cumulative contact time and cumulative mass transport through the skin. With almost no loss of reliability, this simple relationship can be used in place of the more complex micro-activity simulations that require activity data on one- to five-minute intervals. The methods developed in this study can be used to guide dermal exposure model refinements and exposure measurement study design.     

一类广义(2+1)维非自治长短波方程的整体光滑解的存在唯一性

利用先验估计和Galerkin方法,研究了非线性广义耗散(2+1)维非自治长短波方程在H4per(Ω)×H3per(Ω)上光滑解的整体存在唯一性.     

From leprosy to The Willow Tree: decoding disability and Islamic spirituality in Iranian film

The lack of attention in academic discourse to representations of disability in films from the Middle East has led to an incomplete picture of representations of disability in global cinema. For instance, the diverse meanings of disability in Iranian cinema and the influence of disability on the emergence of Iranian New Wave cinema have been almost completely ignored by scholars. A number of award-winning films from Iran have featured disability as central to their narratives – such as The House is Black (1963), Taste of Cherry (1997), The Color of Paradise (1999), The Willow Tree (2005), and The Painting Pool (2013). Disability in these films serves alternatively as a symbol of spiritual possibility, a mark of marginalization, and a covert social critique. These films examine the emotional, physical, and social implications of disability, while celebrating the cultural power of film to challenge social, religious, and artistic barriers.     

“三驾马车”的创作及其新变

20世纪九十年代中期,被誉为"三驾马车"的何申、谈歌、关仁山三位河北籍作家在文坛上先后发表了他们的代表作,掀起了"现实主义冲击波"."三驾马车"的成功有着深刻的社会历史原因,他们后期的创作在题材和文学视野上,以及作品的批判精神上也表现出了新的变化.     

制度视角的国家(地区)间经济横向波动研究

制度是有时效性的 ,制度变迁是非连续的 ,制度结构的高效和低效的循环导致一国经济增长的波动。一些国家 (地区 )高效的制度结构及其经济高增长的示范效应会引起相关国家 (地区 )进行制度的学习和引进 ,这种制度的横向传播引起相关国家间互相关联的经济横向波动。本文研究了经济横向波动的制度传播途径和机理 ,并用模型对这种横向波动进行了分析。本文的研究表明 ,制度的相互影响和传播是相关国家 (地区 )间经济横向波动的先导性、基础性原因。     

推广的简单方程方法对两个非线性发展方程的应用

本文借助于计算机代数系统Mathematica,利用推广的简单方程方法成功获得了Joseph-Egri方程和(2+1)-维KP方程新的精确行波解,并且分别以含两个任意参数的双曲函数、三角函数及有理函数等三种形式表示,其中双曲函数表示的行波解中参数取特殊值时可得到孤波解。