旅游资源竞争力与旅游收入关系实证分析——以安徽省17地市为例

在构建旅游资源竞争力评价指标体系的基础上,运用位序得分法对安徽省17个地市的旅游资源竞争力进行了评价,同时借助两轴折线图、散点图及拟合曲线等工具对17个地市旅游资源竞争力与旅游收入关系进行了实证分析。结果表明,安徽省绝大多数地市旅游业发展仍依赖于旅游资源;少数地市旅游资源竞争力与旅游收入出现偏离,成为非旅游资源依赖性城市。从资源属性来看,综合类旅游资源与旅游收入的相关性最大,其次为自然类旅游资源,人文类的相关性最小。     

危险废物回转式流化冷渣多段焚烧系统焚烧特性研究

危险废物的处理和处置是摆在我国各级市政府面前的紧迫任务。然而我国已经运行的危险废物焚烧装置普遍存在回转窑挂壁结渣、热灼减率偏高和污染排放超标等问题,作者通过将回转窑和流化床特点相结合的方法提出了一种新型危险废物回转式流化冷渣多段焚烧处置装置。该装置采用回转窑(一燃室)、二燃室和流化床结合的热解-流化焚烧工艺,特别是采用控制窑头温度避免了回转窑挂壁结渣;采用流化冷渣装置延长未燃烬渣的焚烧时间,解决了热灼减率偏高问题;水冷式烟气急冷装置可以将烟气温度从1 100℃降到200℃,防止了二恶英的尾部低温再生成。该系统运行稳定可靠,可以处理医疗垃圾和大多数的固态和液态危险废物,实现了烟气污染物尤其是二恶英排放达到国家标准的目标。同时对该系统运行时窑头温度分布、二燃室炉膛出口氧量变化、回转窑和炉膛升温特性、燃烧室外壁温度分布等几方面运行数据都进行了详细的介绍,为危险废物焚烧炉的运行提供了宝贵的经验数据。     

电渗透脱水污泥干燥特性曲线及干燥模型简

通过电渗透脱水技术及自然风干技术两种预处理方式降低污泥含水率,当污泥初始含水率相近时,研究经两种方式处理后污泥的干燥特性曲线,并对电渗透脱水污泥干燥特性曲线的优势情况进行探讨。在40~120℃的低温条件下,研究电渗透脱水污泥（泥饼厚度为3.5 mm）的干燥特性曲线并分析其干燥特性。通过所得电渗透脱水污泥的干燥特性曲线,引入薄层污泥干燥模型进行数值分析。结果表明,在实验条件下,电渗透脱水污泥的干燥速率要优于自然风干污泥的干燥速率。随着温度的升高,电渗透脱水污泥的干燥速率随之升高,干燥到所需含水率的时间则随之减少。Logarithmic模型比其他模型更适合描述薄层电渗透脱水污泥在低温条件下的干燥特性。     

Low dose effects and non-monotonic dose responses for endocrine active chemicals: Science to practice workshop: Workshop summary

A workshop was held in Berlin September 12–14th 2012 to assess the state of the science of the data supporting low dose effects and non-monotonic dose responses (“low dose hypothesis”) for chemicals with endocrine activity (endocrine disrupting chemicals or EDCs). This workshop consisted of lectures to present the current state of the science of EDC action and also the risk assessment process. These lectures were followed by breakout sessions to integrate scientists from various backgrounds to discuss in an open and unbiased manner the data supporting the “low dose hypothesis”. While no consensus was reached the robust discussions were helpful to inform both basic scientists and risk assessors on all the issues. There were a number of important ideas developed to help continue the discussion and improve communication over the next few years.     

曲线拟合在环境空气污染物浓度预测中的应用

从分析环境空气污染物月均值的时间变化规律入手 ,找出与污染物变化特征相对应的数学函数 ,应用曲线拟合的方法 ,结合统计回归分析 ,建立曲线拟合方程。该方程可应用于污染物浓度的中长期预测     

废弃绿茶对水溶液中Co2+的吸附研究

利用废弃绿茶叶粉末(简称茶叶末)作为吸附剂,考察了pH、温度、时间等对水溶液中Co2+的影响。结果表明:(1)茶叶末对Co2+的吸附量随着pH的上升而上升,其中pH=5.50为最佳。茶叶末对Co2+的吸附量均随时间延长呈现上升趋势,吸附速度先快后慢,吸附最佳时间为90min。(2)不同温度下,茶叶末对Co2+的吸附较好地符合Langmuir模型。该吸附过程是化学离子交换过程,主要发生在重金属离子与羟基、氨基的氢原子之间。(3)茶叶末对Co2+的吸附是自发、放热过程,降温有利于吸附,反应时吸附界面上的混乱度增加。(4)盐酸是很好的解吸介质,解吸率为92.65%。通过灼烧(或燃烧)可以回收水溶液中绝大部分的Co2+,不仅减小了对环境的污染,而且节约了资源。     

多重线性软化材料的拉伸应变局部化及力学行为分析

峰后线性应变软化本构关系的拉伸局部化带内部的塑性应变分布及试样的峰后应力—应变关系的理论解答不适用于复杂情形,在双线性应变软化条件下,得到了拉伸局部化带内部的塑性拉伸应变分布及试样的峰后应力—应变关系的理论表达式,又将其推广为多重线性应变软化情形,这在一定程度上拓展了考虑峰后应变局部化的单向拉伸试样力学行为模型的适用范围。拓展后的模型具有广泛的适用性,可模拟峰后的Ⅰ类及Ⅱ类(回跳)行为。通过选择适当的塑性模量(依赖于应力水平)与拉伸局部化带宽度的比值,本文的模型可以精确地模拟多种准脆性材料(例如岩石及混凝土)在单向拉伸条件下的复杂的峰后力学行为。     

Nonparametric Monte Carlo Simulation for Flood Frequency Curve Derivation: An Application to a Korean Watershed1

Abstract: A mix of causative mechanisms may be responsible for flood at a site. Floods may be caused because of extreme rainfall or rain on other rainfall events. The statistical attributes of these events differ according to the watershed characteristics and the causes. Traditional methods of flood frequency analysis are only adequate for specific situations. Also, to address the uncertainty of flood frequency estimates for hydraulic structures, a series of probabilistic analyses of rainfall‐runoff and flow routing models, and their associated inputs, are used. This is a complex problem in that the probability distributions of multiple independent and derived random variables need to be estimated to evaluate the probability of floods. Therefore, the objectives of this study were to develop a flood frequency curve derivation method driven by multiple random variables and to develop a tool that can consider the uncertainties of design floods. This study focuses on developing a flood frequency curve based on nonparametric statistical methods for the estimation of probabilities of rare floods that are more appropriate in Korea. To derive the frequency curve, rainfall generation using the nonparametric kernel density estimation approach is proposed. Many flood events are simulated by nonparametric Monte Carlo simulations coupled with the center Latin hypercube sampling method to estimate the associated uncertainty. This study applies the methods described to a Korean watershed. The results provide higher physical appropriateness and reasonable estimates of design flood.     

深圳市新一代暴雨强度公式的研制

首先构造了深圳市新一代暴雨强度公式研制的路线图，重点是利用深圳市气象局1954-2003年50年间的暴雨记录，用指数分布和P-Ⅲ分布进行分布曲线拟合和选优，得到了理论上的雨强-历时-重现期三联表，在此基础上再分别采用最优法、二分搜索法和广义逆法等3种方法求解分公式和总公式参数，根据误差最小的原则确定最优方法。结果表明：由指数分布拟合分布曲线，经过上述步骤求解得到的公式参数，误差最小，符合相关国标要求。     

EFFECT OF ORIENTATION OF SPATIALLY DISTRIBUTED CURVE NUMBERS IN RUNOFF CALCULATIONS1

ABSTRACT: The NRCS curve number approach to runoff estimation has traditionally been to average or “lump” spatial variability into a single number for purposes of expediency and simplicity in calculations. In contrast, the weighted runoff curve number approach, which handles each individual pixel within the watershed separately, tends to result in larger estimates of runoff than the lumped approach. This work proposes further enhancements that consider not only spatial variability, but also the orientation of this variability with respect to the flow aggregation pattern of the drainage network. Results show that the proposed enhancements lead to much reduced estimates of runoff production. A revised model that considers overland flow lengths, consistent with existing NRCS concepts is proposed, which leads to only mildly reduced runoff estimates. Although more physically‐based, this revised model, which accounts directly for spatially distributed curve numbers and flow aggregation, leads to essentially the same results as the original, lumped runoff model when applied to three study watersheds. Philosophical issues and implications concerning the appropriateness of attempting to disaggregate lumped models are discussed.