Inferring Hydrograph Components from Rainfall and Streamflow Records Using a Kriging Method-Based Linear Cascade Reservoir Model1

Cheng, Shin-jen, 2010. Inferring Hydrograph Components From Rainfall and Streamflow Records Using a Kriging Method-Based Linear Cascade Reservoir Model. Journal of the American Water Resources Association (JAWRA) 46(6):1171–1191. DOI: 10.1111/j.1752-1688.2010.00484.x Abstract: This study investigates the characteristics of hydrograph components in a Taiwan watershed to determine their shapes based on observations. Hydrographs were modeled by a conceptual model of three linear cascade reservoirs. Mean rainfall was calculated using the block Kriging method. The optimal parameters for 42 events from 1966-2008 were calibrated using an optimal algorithm. Rationality of generated runoffs was well compared with a trusty model. Model efficacy was verified using seven averaged parameters with 25 other events. Hydrograph components were characterized based on 42 calibration results. The following conclusions were obtained: (1) except for multipeak storms, a correlation between base time of the surface runoff and soil antecedent moisture is a decreasing power relationship; (2) a correlation between time lag of the surface flow and soil antecedent moisture for single-peak storms is an increasing power relationship; (3) for single-peak events, times to peak of hydrograph components are an increasing power correlation corresponding to the peak time of rainfall; (4) the peak flows of hydrograph components are linearly proportional to that of total runoff, and the peak ratio for the surface runoff to total runoff is approximately 78 and 13% for subsurface runoff to total runoff; and (5) the relationships of total discharges have direct ratios between hydrograph components and observations of total runoffs, and a surface runoff is 60 and 32% for a subsurface runoff.     

Financing electronic waste recycling Californian households' willingness to pay advanced recycling fees

The growth of electronic waste (e-waste) is of increasing concern because of its toxic content and low recycling rates. The e-waste recycling infrastructure needs to be developed, yet little is known about people's willingness to fund its expansion. This paper examines this issue based on a 2004 mail survey of California households. Using an ordered logit model, we find that age, income, beliefs about government and business roles, proximity to existing recycling facilities, community density, education, and environmental attitudes are significant factors for explaining people's willingness to pay an advanced recycling fee (ARF) for electronics. Most respondents are willing to support a 1% ARF. Our results suggest that policymakers should target middle-aged and older adults, improve programs in communities with existing recycling centers or in rural communities, and consider public-private partnerships for e-waste recycling programs.     

NO2对二甲苯光氧化生成SOA及其吸光度影响

NO₂是大气中常见污染气体,影响大气二次有机气溶胶（Secondary organic aerosol,SOA）的形成.运用实验室烟雾箱模拟二甲苯大气光氧化反应过程,研究NO₂对二甲苯SOA生成量、光学特性和化学组成的影响.结果显示,NO₂促进二甲苯SOA的形成,NO₂浓度从0增长到900×10^-9,二甲苯SOA的质量浓度增长2倍左右,并且邻二甲苯SOA质量浓度大于对二甲苯SOA.这是因为邻位取代基相比于对位取代基更倾向于形成醛,有利于聚合反应形成低聚物,促进SOA形成.此外,NO₂浓度增加显著提高所生成SOA的单位质量吸光度（Mass absorption coefficients,MAC）,这是由于前体物邻二甲苯和对二甲苯化学结构不同,邻二甲苯所生成的含氮有机物具有更强吸光性,从而导致邻二甲苯SOA的MAC_{λ=365 nm}大于对二甲苯SOA的MAC_{λ=365 nm}.在线气溶胶质谱仪分析结果进一步显示：二者光化...     

服役态Super304H耐热钢管显微组织演变及高温力学性能研究

目的 探究服役Super304H钢管外壁粗晶组织演变及其对高温力学性能的影响,为超超临界机组运行管理与安全评估提供技术支持。方法 针对不同服役时间的Super304H耐热钢管,开展显微组织演变及650 ℃高温拉伸力学性能研究,着重探讨钢管外壁奥氏体晶粒异常长大、第二相析出长大及其对钢管高温力学性能的影响规律。结果 服役态Super304H钢管中的第二相以富铜相、MX相及M23C6相为主,其外壁奥氏体晶粒异常长大,形成粗晶区,而靠近内壁钢管中的奥氏体晶粒长大不明显,为细晶区。相对于细晶区,粗晶区奥氏体晶界及晶内析出更多的第二相,尺寸更大,弥散度降低,导致粗晶区高温拉伸性能显著降低。结论 长期高温运行的Super304H耐热钢管应加强监督,消除因外壁奥氏体晶粒异常长大而带来的胀管等安全隐患。     

蒙城台磁变仪跳动及其原因的初探

2001-03-09蒙城地震台地磁磁变仪CB-3(观测仪，备份仪)同时出现三个分量动线的跳动，分析表明蒙城地震台地磁总强度F、 垂直强度Z发生变化。 其原因可能是强电流作用下，地下介质电性变化所致。     

Assessment of natural components of PM10 at UK urban and rural sites

Proposals from the European Commission have raised the possibility that Member States may be able to subtract the concentrations of natural components of airborne particulate matter from measured concentrations when evaluating compliance with EU Limit Values. By applying the pragmatic mass closure model [Harrison et al., 2003. A pragmatic mass closure model for airborne particulate matter at urban background and roadside sites. Atmospheric Environment 37, 4927–4933] to chemical composition data for PM₁₀, it has been possible to estimate the concentrations of natural sea salt, strongly bound water and secondary organic carbon (which is assumed wholly biogenic) to the measured mass of PM₁₀. Because of the difficulty in distinguishing between natural and anthropogenic crustal dusts, the contribution of natural windblown dust and soil has not been accounted for. When the natural components are estimated for two urban and one rural site in the UK, the long-term mean PM₁₀ concentration is reduced by between 5.2 and 7.3 μg m⁻³. The number of exceedences of the 50 μg m⁻³ 24-h limit value falls dramatically from 54 to 21 (from a total of 291 days) at an urban street canyon site, 7 to 3 (n=292 days) at an urban background site and from 8 to 0 (n=241 days) at a rural site when using gravimetric PM₁₀ concentrations. The calculations have also been performed using PM₁₀ concentrations measured by TEOM increased by a factor of 1.3 as recommended by the European Commission as an interim means of estimating gravimetric equivalency, and the number of exceedences of the 24-h limit value fell from 92 to 47 (from a total of 291 days) at the urban street canyon site, from 11 to 3 (n=292 days) at the urban background site and from 6 to 3 (n=241) at the rural site. Clearly, therefore, application of this proposed measure would make a very major difference to the likelihood of compliance or otherwise with the 24-h limit value for PM₁₀.     

城市污水厂部分反硝化滤池启动及运行

采用生物滤池探究部分反硝化（NO₃^--N还原到NO₂^--N）工艺应用于城市污水厂深度脱氮的可行性.以实际二级出水为进水,考察滤速、碳氮比（C/N）等影响因素对滤池快速启动及稳定运行的影响,分析了滤池沿程水质变化和系统微生物群落结构.结果表明,控制高滤速和低C/N,3d可实现部分反硝化滤池的快速启动,滤池120d平均亚硝态氮累积率（NTR）为60.3%,最高可达82.1%,成功构建了连续流生物膜部分反硝化工艺.高滤速条件有助提高滤池的NO₂^--N积累率,C/N对NO₂^--N积累率的影响较小,C/N为2~4,部分反硝化滤池的NTR维持在62.0%.沿程数据表明底部40cm的滤料层是部分反硝化滤池NO₃^--N去除和NO₂^--N累积的主要反应区域.由于采用实际水厂二级出水进行研究,扫描电镜和高通量测序结果表明存在多种具有反硝化功能的微生物,系统的微生物多样性较高.     

南京北郊水溶性离子污染特征及其光学特性

为了分析南京北郊水溶性离子污染特征及其消光贡献,于2017年3月15日~4月15日、7月和10月开展了PM_2.5观测实验,分析了南京春夏秋3个季节的PM_2.5及其组分浓度特征、水溶性离子及其前体物转化特征以及水溶性离子的光学特性.结果表明,采样期间PM_2.5的质量浓度为（93.8±40.3）μg/m³,其中54.2%为水溶性离子,其总质量浓度为（50.9±25.6）μg/m³,而二次水溶性离子（SNA）占水溶性离子的76.8%.各水溶性离子组分分布为：NO₃^- > SO₄^2- > NH₄⁺ > Ca²⁺ > Cl^- > NO₂^- > K⁺ > F^- > Mg²⁺ > Na⁺.在季节变化上,PM_2.5和主要水溶性离子均为春季高,夏季低,但夏季NO₃^-4^2-.硫转化率（SOR）和氮转化率（NOR）在采样期的均值分别为0.38、0.22,这说明南京有较强的二次转化过程.采样期间,平均[NO₃^-]/[SO₄^2-]的值为1,这说明水溶性离子主要来源于移动源的排放.通过IMPROVE公式计算的大气消光系数低于实际值,但能够较为准确的反映出南京消光系数的趋势.各组分消光贡献从大到小分别为（NH₄）₂SO₄（38.9%）、NH₄NO₃（36.7%）、POM（13.6%）、EC（9.3%）、NO₂（1.5%）.其中SNA的消光贡献占70%以上,春季的SNA消光贡献最大,而夏季的最小.     

新疆独山子区VOCs组成及其对O3和SOA的贡献

参照美国环保署USEPATO-14标准方法,分别于非采暖、采暖和沙尘期采集新疆独山子区空气样品,用预浓缩仪和气相色谱/质谱联用系统对其挥发性有机物（VOCs）进行分析.结果表明,采样期间独山子区各类VOCs对总VOCs的贡献大小依次是：烷烃（61.80%） > 烯烃（18.62%） > 芳香烃（10.16%） > 乙炔（9.42%）;用气溶胶生成系数（FAC）估算VOCs的二次有机气溶胶（SOA）生成潜势表明,对SOA生成贡献最大的是芳香烃,在非采暖、采暖和沙尘期的贡献率分别为97.80%、87.28%和69.52%;用SPSS软件和广义相加模型（GAM）分析气象因素、VOCs、O₃及NOx之间的关系,表明高温干燥天气有利于O₃生成,且独山子区O₃生成主要受VOCs控制,一些烯烃（如1-丁烯）与O₃呈显著线性关系.     

北京市冬季重污染期间PM2.5及其组分演变特征

通过实时在线监测了2018年11月27日~2019年1月15日北京市城区PM_2.5、水溶性无机离子（Na⁺、NH₄⁺、K⁺、Mg²⁺、Ca²⁺、F^-、Cl^-、NO₂^-、NO₃^-、SO₄^2-、PO₄^3-）、碳质组分（有机碳OC、元素碳EC）的质量浓度以及气态污染物浓度和气象要素,收集整理了近20年北京市冬季PM_2.5、主要离子组分以及碳质组分浓度,分析研究了1999~2018年北京市冬季PM_2.5、离子、碳质组分的变化特征,重点探讨了监测期间清洁日与两个典型重污染事件PM_2.5及其组分的演变特征.结果表明：研究期间PM_2.5浓度为53.5μg/m³,达到近20年北京市冬季较低值,且大气主要污染源由煤烟型污染源转变为燃煤型与机动车尾气复合型污染源.监测期间,湿度高、微弱的西南风导致重污染产生,清洁日、污染事件I与污染事件II PM_2.5平均浓度分别为32.5,138.9,146.8μg/m³且不同时段PM_2.5日变化趋势存在差异.各离子浓度变化为：NO₃^- > NH₄⁺ > SO₄^2- > Cl^- > K⁺ > Ca²⁺ > Na⁺ > PO₄^3- > F^- > NO₂^-~Mg²⁺,总水溶性离子浓度为24.6μg/m³占PM_2.5总浓度的46.0%,其中SNA浓度占总离子浓度的83.7%,是离子中最主要的组分.碳质组分浓度达到近二十年北京市冬季最低值,变化为：一次有机碳POC > EC > 二次有机碳SOC,OC与EC相关系数达到0.99,一次燃烧源对污染过程有较大贡献.NH₄⁺在清洁日与污染II中富集,主要以（NH₄）₂SO₄、NH₄NO₃和NH₄Cl形式存在,在污染I中较少,仅以（NH₄）₂SO₄和NH₄NO₃存在.在污染I和II期间,SO₄^2-的形成昼夜均受相对湿度与NH₃影响;NO₃^-的形成白天受O₃与NH₃的影响,夜间受相对湿度和NH₃的影响.