Integration of Low-Impact Development into the International Stormwater BMP Database

Low impact development (LID) strategies are being encouraged in many communities as an approach to reduce potential adverse impacts of development on receiving streams. Many questions exist regarding how well various LID strategies perform in different settings, just as similar questions have been raised regarding performance of traditional stormwater best management practices (BMPs). Whereas historical focus on BMP performance has been water quality concentrations or loads, characterization of volume reduction benefits for both conventional and LID practices is increasingly an objective of researchers and stormwater managers. More than a decade ago, Urban Water Resources Research Council (UWRRC) members worked to develop a set of standardized monitoring and reporting protocols for traditional BMPs and to establish a master database for the purpose of evaluating BMP performance and the factors affecting performance. This effort culminated in the International Stormwater BMP Database (www.bmpdatabase.org), which contains data for more than 360 BMPs and continues to operate as a clearinghouse for stormwater BMP data and performance analyses. During 2008–2009, the International Stormwater BMP Database project expanded to better integrate LID into the database and develop a set of metrics that can be used to characterize BMP performance with regard to surface runoff volume reduction. This paper provides a condensed overview and progress report on the LID-focused effort, including the following topics: (1)?monitoring guidance for LID at the overall site development level, (2)?an overview of recent changes to the International Stormwater BMP Database to better accommodate LID studies, (3)?a summary of LID studies currently included in the database, and (4)?a proposed approach for evaluating performance of LID studies with regard to reducing surface runoff volumes.     

采用煤矸石为原料合成β-SiAlON晶须及其显微结构研究

以煤矸石和碳黑为主要原料,在1800 K下碳热还原氮化合成了纯度较高、含有大量晶须的β-SiAlON材料.FESEM照片表明β-SiAlON晶须多为细长柱状,直径120～220 nm,长度1.5～5 μm,晶须生长机制由VLS(vapor-liquid-solid)机制和VS(vapor-solid)机制组成.     

城市增长边界的性质及划定方法探讨——杭州市生态带保护与控制规划实践

随着我国城市化进程加速推进,城市增长与土地资源和生态环境保护等矛盾已日益凸显。划定城市增长边界(UGB)是协调建设与生态保护的有效手段。结合杭州生态带规划案例,对城市增长边界的性质进行辨析,提出刚性UGB与弹性UGB的区别。运用生态敏感性分析、景观生态安全格局构建和建设用地规划等方法,以及面对建设与保护冲突的规划决策方法,探讨了UGB的划定方法,并指出UGB在我国规划应用中需要进一步完善的方面。     

两种紫外成像参数在绝缘子故障诊断中的比较

绝缘子的运行状态直接关系到高压电网的稳定性,在运行过程中会出现绝缘性能下降同时伴随着表面放电,可以用紫外成像仪对其运行状态进行检测。目前,主要的参数是"紫外光斑面积"和"光斑直径",为了对它们在绝缘子故障诊断中的性能有一个对比,笔者通过喷水分级法在现场选择了正常、良好、微痕、劣化和严重老化5种绝缘状态的同一种绝缘子,在实验室搭建平台,在加压8、10、15 kV的情况下,通过南非CoroCAM504紫外成像仪对绝缘子放电情况拍摄足够的紫外图片,运用数字图像处理算法提取了两个参数值,通过MATLAB数字仿真,得到了这两种参数随绝缘状态的变化趋势。结果表明:①在绝缘子绝缘状态艮好的时候,光斑面积和光斑直径几乎可以忽略,对应性比较好,反之,在这两个参数都很小的时候,说明绝缘子绝缘良好;②在绝缘子绝缘出现问题时,二者都有上升趋势,但是光斑面积有一个转折点"4",而光斑直径没有,这说明,当绝缘劣化到一定程度时,光斑面积就没有太大区分度了,而光斑直径则可以区分。最终为绝缘子的运行状态的评估提供了量化的依据和一定的指导。     

真丝磨损后形态结构的研究

利用扫描电镜研究真丝绸磨损后的形态结构得出,真丝磨损过程分为丝胶的磨损和丝素的磨损两个过程,文章分析阐述了丝胶由磨损刮落到脆裂剥落;丝素磨损的原纤化以至原纤维的断裂等过程。     

Understanding the Meniscus‐Guided Coating Parameters in Organic Field‐Effect‐Transistor Fabrications

Meniscus‐guided coating (MGC) is mainly applicable on the soluble organic semiconductors with strong π–π overlap for achieving single‐crystalline organic thin films and high‐performance organic field‐effect‐transistors (OFETs). In this work, four elementary factors including shearing speed (v), solute concentration (c), deposition temperature (T), and solvent boiling point (T_b) are unified to analyze crystal growth behavior in the meniscus‐guided coating. By carefully varying and studying these four key factors, it is confirmed that v is the thickness regulation factor, while c is proportional to crystal growth rate. The MGC crystal growth rate is also correlated to latent heat (L) of solvents and deposition temperature in an Arrhenius form. The latent heat of solvents is proportional to T_b. The OFET channels grown by the optimized MGC parameters show uniform crystal morphology (Roughness R_q < 0.25 nm) with decent carrier mobilities (average µ = 5.88 cm² V^?1 s^?1 and highest µ = 7.68 cm² V^?1 s^?1). The studies provide a generalized formula to estimate the effects of these fabrication parameters, which can serve as crystal growth guidelines for the MGC approach. It is also an important cornerstone towards scaling up the OFETs for the sophisticated organic circuits or mass production.     

Modes of making smart cities: Or,practices of variegated smart urbanism

The ‘actually existing’ smart city is not a monolith. It is not directed by a universal logic, nor does it develop in a standardised way. As recent research has argued, the spatial, material, and political contexts of cities have major influence over what smart urbanism looks like in practice. This paper adds analytical depth to, and broadens the geographical scope of, research on the variegated modes of making smart cities. Based on empirical research in multiple Australian cities we use three case studies to explore three different modes of smart urbanism, each one centred on the interests of a different key actor: corporate-centric, citizen-centric, and planner-centric. These different modes can, and do, co-exist in the same city. At times, they are competing logics that fight to pull the city in different directions. Yet, they can also work together to shape smart city initiatives. In describing these different modes, we pay particular attention to the ways that these projects and strategies must contend with the already existing spatial, cultural, and political contexts of each place.     

一种图像序列中运动目标检测的鲁棒算法

人体运动检测在计算机视觉中是一项很基本的任务,在图像序列中检测人体运动是一种可行的方法。在做运动目标检测时,常用的图像差分方法有着固有的缺点,用一种改进的图像差分方法进行目标检测,利用一种全局阈值分割方法对差分图像进行二值化,通过数学形态学计算法进行滤波,可有效地克服这些缺点。实验结果表明,此方法能很好地检测低信噪比图像序列中的运动目标。     

结合数学形态学和图像融合的边缘检测算法

工业CT图像边缘检测是工业CT图像处理中一项十分重要的工作和预处理步骤,图像的最终处理结果取决于边缘检测的优劣程度。本文首先介绍了几种经典的图像边缘检测方法,并用这几种算法对工业CT图像进行了计算机仿真。通过对仿真结果的对比和分析,作者提出了基于数学形态学和图像融合相结合的图像边缘检测算法MDY并在ImageJ软件上编程实现。实验结果表明该算法能够有效地抑制噪声,完整的检测边缘,且优于其他传统边缘检测算法。     

多结构元素的数学形态学图像边缘检测算法

数学形态学作为一门新兴的、以形态为基础对图像进行分析的学科，已得到人们的广泛关注，并应用于图像处理的许多方面。本文提出一种基于多结构元素的数学形态学图像边缘检测算法，该算法通过构造4个不同方向的结构元素，应用形态学梯度算子得到图像4个方向的边缘检测结果，并将这些结果进行加权平均，得到最终的图像边缘。为验证算法的效果，给出了本文算法和几种传统算子对Lena图像进行边缘提取的实验结果。结果表明：本文算法成功地完成了图像的边缘检测，且检测效果明显优于经典的Sobel算子，Laplace算子和Canny算子。