晋东南地区冬季PM2.5污染输送路径分析

利用2017~2019年晋城市和长治市冬季PM_2.5逐时浓度资料、地面风场数据等,结合HYSPLIT轨迹模型和中尺度数值模式WRFV4.2分析了晋东南地区冬季PM_2.5污染的特征和传输特点.结果表明,晋城市冬季PM_2.5污染程度高于长治市.受地形影响,晋城市地面盛行偏南风、偏北风和西北风,污染方向主要为偏南风和偏北风;长治市近地面盛行偏南风,该风向污染频率最高.影响晋城市和长治市污染的潜在源区主要分布在偏西、东北和东南方向,偏西气流来自陕西省中部,东北气流来自河北省西南部,东南气流来自河南省中东部.污染经过晋东南地区主要影响山西省中南部和北京南部.通过数值模拟流场,结合潜在源区和影响区域的分析结果,在均压场或高压后部的天气形势下,晋东南地区污染输送路径包括来自东北方向（河北省西南部一带）的气流,沿长治市东北部的滏口陉向晋东南地区输送污染物及沿太行山东麓向南在晋豫交界处的太行陉发生转折向晋东南地区输送污染物;来自东南方向（河南北部及东部）的气流输送和来自偏西方向（陕西中南部）的气流输送.污染物经过晋东南地区向北输送至山西省中南部,部分经过山西省中东部的井陉输送至北京南部.     

面向实施的市级国土空间规划传导思路与技术方法

规划传导是保障国土空间规划实施的关键环节,从理念层面的治理转型、规则层面的事权匹配、空间层面的要素管理入手,对市级规划传导的技术思路与方法途径进行了研究。研究表明：空间规划具有的基础性、有限性和动态性等特征是规划传导的基础出发点,应建立起涵盖理念宽度、事权力度和要素精度的规划传导框架。在此基础上提出双向反馈、权责清单、刚弹结合、尺度容差、动态平衡等技术思路来分步推进规划传导,并以广州为例提出了规划传导实施层面的方法途径,为建立能用、管用、好用的规划传导政策规则和体制机制,为完善国土空间规划体系和推动规划有效实施提供研究支撑。     

基于AIS数据的中国沿海集装箱港口碳排放

为了精确有效地测量船舶在港碳排放,提出了一种基于海量船舶AIS (Automatic identification System)航行轨迹数据的港口碳排放计算框架,并结合上市港务公司经营数据,估算港口碳排放承担能力.以中国11个沿海主要集装箱港口为例,采用2018年全球4280艘集装箱船的AIS轨迹全年数据计算碳排放社会成本.结果显示:中国沿海集装箱港口碳排放量与船舶抵港艘次整体呈正相关,上海港是全球第一大集装箱港口,2018年其港口CO₂排放量最高,为69.3万t;船舶靠港作业时,在泊和锚泊状态CO₂的排放比例较高,占碳排放比例的65.8%;从CO₂排放社会成本来看,上海港域内的船舶碳排放社会成本最高,2018年需要支付2459.6万元,从承担碳排放社会成本的能力来看,连云港压力较大,每亿营业收入需要承担碳排放社会成本24.46万元.     

汾渭平原吕梁市颗粒物潜在源及输送通道分析

基于汾渭平原吕梁市2017~2019年颗粒物浓度监测数据和地面气象观测数据,利用后向轨迹聚类分析法以及潜在源贡献函数(PSCF)等方法研究了吕梁市冬季PM₁₀和PM_2.5大气污染特征及其潜在源区,最后结合轨迹密度分析法(TDA)、轨迹停留时间分析法(RTA)对轨迹聚类分析得到污染输送通道进行补充分类,并分析了不同输送通道的输送特征.研究发现,吕梁市2017~2019年颗粒物年均浓度逐年下降,其中PM₁₀下降了28μg/m³,PM_2.5下降了17μg/m³,冬季下降幅度最大.3a冬季风向风速和浓度的统计分析表明吕梁市颗粒物浓度受东北和西南风影响最为显著,其原因是受当地三川河河谷地形的影响.影响吕梁市PM₁₀污染的潜在源区主要位于西南方向,PM_2.5污染的潜在源区主要分布在西南、东和东南方向,颗粒物污染输送通道可概括为:西北、西南和偏东(东+东南)通道.西北通道气流移动速度快,途经新疆、内蒙、甘肃和陕西北部等区域;西南通道气流移动速度慢,主要途经陕西中南部渭河平原等污染严重的区域;偏东通道的气流移动速度慢,气流先沿太行山东麓南下,在经过太行山的横断山谷(太行陉、井陉等)时转向进入山西.PM₁₀污染时西北通道贡献最大,偏东通道贡献最小,且两个通道下绝大多数发生的均是轻度污染,占比都在90%左右;PM_2.5污染时三类通道下发生轻度污染的比重较PM₁₀均下降,西南和偏东通道下发生中度污染以上的比重在50%左右,且西南和偏东通道途经的区域恰好是PSCF计算得到的潜在源区位置,说明了西南和偏东气流容易将细颗粒物输送至吕梁.WRF (天气预报模式)的风场模拟较为直观的解释了三类污染输送通道,且复杂地形是形成污染输送通道的一个重要因素.西北和西南污染输送通道主要受吕梁山脉的影响,偏东污染输送通道主要受太行山及其横谷的影响.     

基于极大似然法的土壤重金属删失数据的相关性

基于极大似然法（MLE）,通过构建不同情形下的似然函数,提出了删失数据相关性估计的方法.分别研究了样本容量、删失比例、总体相关系数与干扰项等因素对估计值准确性的影响.同时,将MLE与替换法（通常将删失部分替换为LOD或LOD/2）和删除法（直接将删失部分删除）做对比,检测了MLE的精准度.以澳大利亚土壤普查数据作为实例对方法进行了实例应用.结果表明：样本容量越大,研究中的MLE的结果越准确,当样本容量达到2000时,估计值具有较好的稳定性,且受删失比例影响较小.MLE的相关系数估计值随删失比例（0%~90%）与总体相关系数变化程度较小,具有渐进无偏性和一致性.添加干扰项对MLE的准确性影响较小,表明其具有较强的鲁棒性.随着删失比例的提升,MLE精确性明显优于删除法和替换法.实际数据的应用结果表明澳大利亚土壤普查数据中,Ag与Hg有着较高的相关性,Hg与Hf之间相关系数几乎为0.     

保护陆生生态的土壤铜环境基准研究

通过调研国内外Cu生态毒理研究,收集并筛选土壤Cu的10%效应浓度（EC₁₀）和无效应浓度（NOEC）,分组构建陆生植物/无脊椎动物和土壤生态过程的物种敏感性分布模型（SSD）,结合模型平均法推导不同土地利用方式下重金属Cu的生态安全阈值.针对保护陆生植物/无脊椎动物,自然保护地和农业用地土壤、公园用地、住宅用地和工/商用地的土壤Cu生态阈值分别为10.9~38.9,21.0~77.5,36.6~124,47.6~151mg/kg;针对保护生态过程,自然保护地和农业用地土壤、公园用地、住宅用地和工/商用地的土壤Cu生态阈值分别为4.49~72.2,19.9~135,60.9~220,96.8~277mg/kg.     

Driver licensing,motor-vehicle crashes,and moving violations among older adults

IntroductionDriving is important for well-being among older adults, but age-related conditions are associated with driving reduction or cessation and increased crash risk for older drivers. Our objectives were to describe population-based rates of older drivers’ licensing and per-driver rates of crashes and moving violations.Methods: We examined individual-level statewide driver licensing, crash, and traffic citation data among all New Jersey drivers aged ≥ 65 and a 35- to 54-year-old comparison group during 2010–2014. Rate ratios (RR) of crashes and moving violations were estimated using Poisson regression.Results: Overall, 86% of males and 71% of females aged ≥ 65 held a valid driver’s license. Older drivers had 27% lower per-driver crash rates than middle-aged drivers (RR: 0.73, 95% CI: 0.73, 0.74)—with appreciable differences by sex—but 40% higher fatal crash rates (RR: 1.40 [1.24, 1.58]). Moving violation rates among older drivers were 72% lower than middle-aged drivers (RR: 0.28 [0.28, 0.28]).Conclusion: The majority of older adults are licensed, with substantial variation by age and sex. Older drivers have higher rates of fatal crashes but lower rates of moving violations compared with middle-aged drivers.Practical applications: Future research is needed to understand the extent to which older adults drive and to identify opportunities to further reduce risk of crashes and resultant injuries among older adults.     

A guide to using the internet to monitor and quantify the wildlife trade

The unrivaled growth in e-commerce of animals and plants presents an unprecedented opportunity to monitor wildlife trade to inform conservation, biosecurity, and law enforcement. Using the internet to quantify the scale of the wildlife trade (volume and frequency) is a relatively recent and rapidly developing approach that lacks an accessible framework for locating relevant websites and collecting data. We produced an accessible guide for internet-based wildlife trade surveillance. We detailed a repeatable method involving a systematic internet search, with search engines, to locate relevant websites and content. For data collection, we highlight web-scraping technology as an efficient way to collect data in an automated fashion at regularly timed intervals. Our guide is applicable to the multitude of trade-based contexts because researchers can tailor search keywords for specific taxa or derived products and locations of interest. We provide information for working with the diversity of websites used in wildlife trade. For example, to locate relevant content on social media (e.g., posts or groups), each social media platform should be examined individually via the site's internal search engine. A key advantage of using the internet to study wildlife trade is the relative ease of access to an increasing amount of trade-related data. However, not all wildlife trade occurs online and it may occur on unobservable sections of the internet.     

Importance of timely metadata curation to the global surveillance of genetic diversity

Genetic diversity within species represents a fundamental yet underappreciated level of biodiversity. Because genetic diversity can indicate species resilience to changing climate, its measurement is relevant to many national and global conservation policy targets. Many studies produce large amounts of genome-scale genetic diversity data for wild populations, but most (87%) do not include the associated spatial and temporal metadata necessary for them to be reused in monitoring programs or for acknowledging the sovereignty of nations or Indigenous peoples. We undertook a distributed datathon to quantify the availability of these missing metadata and to test the hypothesis that their availability decays with time. We also worked to remediate missing metadata by extracting them from associated published papers, online repositories, and direct communication with authors. Starting with 848 candidate genomic data sets (reduced representation and whole genome) from the International Nucleotide Sequence Database Collaboration, we determined that 561 contained mostly samples from wild populations. We successfully restored spatiotemporal metadata for 78% of these 561 data sets (n = 440 data sets with data on 45,105 individuals from 762 species in 17 phyla). Examining papers and online repositories was much more fruitful than contacting 351 authors, who replied to our email requests 45% of the time. Overall, 23% of our email queries to authors unearthed useful metadata. The probability of retrieving spatiotemporal metadata declined significantly as age of the data set increased. There was a 13.5% yearly decrease in metadata associated with published papers or online repositories and up to a 22% yearly decrease in metadata that were only available from authors. This rapid decay in metadata availability, mirrored in studies of other types of biological data, should motivate swift updates to data-sharing policies and researcher practices to ensure that the valuable context provided by metadata is not lost to conservation science forever.     

基于Multi-class SVM的车辆换道行为识别模型研究

自动安全换道是车辆实现无人驾驶的关键,为精确识别行驶车辆换道状态,保证行车安全,设计了一种基于多分类支持向量机(Multi-class Support Vector Machine,Multiclass SVM)的车辆换道识别模型。从NGSIM数据集中选取美国101公路车辆轨迹数据进行分类处理,并将车辆换道过程划分为车辆跟驰阶段、车辆换道准备阶段和车辆换道执行阶段。采用网格搜索结合粒子群优化算法(Grid Search-PSO)对SVM模型中惩罚参数C和核参数g进行寻优标定,利用多分类支持向量机换道识别模型对样本数据进行训练和测试,模型测试精度达97.68%。研究表明,模型能够很好地识别车辆在换道过程中的行为状态,为车辆换道阶段的研究提供支持。