为研究厦门市冬季不同PM2.5污染情境与气象条件和气团轨迹路径特征的关系,结合PM2.5观测数据,使用AGAGE(Advanced Global Atmospheric Gases Experiment)统计方法识别2014—2018年冬季厦门市PM2.5观测值、基线值和污染值情境,通过气象...为研究厦门市冬季不同PM2.5污染情境与气象条件和气团轨迹路径特征的关系,结合PM2.5观测数据,使用AGAGE(Advanced Global Atmospheric Gases Experiment)统计方法识别2014—2018年冬季厦门市PM2.5观测值、基线值和污染值情境,通过气象数据统计和气团后向轨迹聚类对不同PM2.5污染情境下气象条件和气团轨迹路径特征进行探究.结果表明:①厦门市冬季不同PM2.5污染情境下,ρ(PM2.5)及PM2.5污染值情境时长占比均呈波动中下降的趋势,具体表现为冬季PM2.5观测值、污染值和基线值情境下,ρ(PM2.5)平均值分别从2014年的42.2、90.7、16.4μg/m3降至2018年的26.3、56.9、8.8μg/m3,冬季PM2.5污染值情境时长占比从2014年的10.2%降至2018年的3.0%.②冬季PM2.5污染值情境下气象要素呈低风速、低气压、高温度、高相对湿度的特征.③冬季到达厦门市的气团轨迹路径中,局地路径由于大气条件稳定易累积形成PM2.5污染;偏北路径和西北路径易从临近省份携带污染物输入导致PM2.5污染,属于重要的外源污染输入路径;沿海路径和偏西路径均属于清洁路径,但沿海路径易在福建省北部与偏北路径重合形成污染输入,加强了偏北路径的污染物输送能力.研究显示,近年来厦门市冬季PM2.5污染有明显减弱趋势,但不利的气象条件和外来污染输入仍会造成PM2.5污染的发生.展开更多
This study investigates word recognition processes and strategies of intermediate learners of Chinese as a Second Language (CSL) in contextual reading settings. Two intermediate CSL learners were chosen as research ...This study investigates word recognition processes and strategies of intermediate learners of Chinese as a Second Language (CSL) in contextual reading settings. Two intermediate CSL learners were chosen as research participants, and think-aloud methods and retrospective interviews were used to collect data. The data were analyzed by using Moustakas' data analysis procedure, CresweU's three steps and Bogdon and Biklen's data analysis methods. Results indicated that intermediate CSL learners go through different processes of word recognition as it might be automatic, based on context, pronunciation, previous knowledge and the meaning of characters, or, in case of word recognition failure, skipping the words or skipping them but reading them again later; and their word recognition strategies in contextual reading settings mainly include cognitive strategies and self-regulatory strategies. Among these strategies, cognitive strategies consist of direct transformation, translation, interpretation, guessing, inferring and finding key words; and self-regulatory strategies include metacognitive strategies, behavior regulating strategies, emotion regulating strategies and motivation regulating strategies. A model of intermediate CSL learners' word recognition strategies can be constructed based on the results. The present study provides both theoretical and pedagogical implications in the field of CSL vocabulary acquisition and teaching.展开更多
文摘为研究厦门市冬季不同PM2.5污染情境与气象条件和气团轨迹路径特征的关系,结合PM2.5观测数据,使用AGAGE(Advanced Global Atmospheric Gases Experiment)统计方法识别2014—2018年冬季厦门市PM2.5观测值、基线值和污染值情境,通过气象数据统计和气团后向轨迹聚类对不同PM2.5污染情境下气象条件和气团轨迹路径特征进行探究.结果表明:①厦门市冬季不同PM2.5污染情境下,ρ(PM2.5)及PM2.5污染值情境时长占比均呈波动中下降的趋势,具体表现为冬季PM2.5观测值、污染值和基线值情境下,ρ(PM2.5)平均值分别从2014年的42.2、90.7、16.4μg/m3降至2018年的26.3、56.9、8.8μg/m3,冬季PM2.5污染值情境时长占比从2014年的10.2%降至2018年的3.0%.②冬季PM2.5污染值情境下气象要素呈低风速、低气压、高温度、高相对湿度的特征.③冬季到达厦门市的气团轨迹路径中,局地路径由于大气条件稳定易累积形成PM2.5污染;偏北路径和西北路径易从临近省份携带污染物输入导致PM2.5污染,属于重要的外源污染输入路径;沿海路径和偏西路径均属于清洁路径,但沿海路径易在福建省北部与偏北路径重合形成污染输入,加强了偏北路径的污染物输送能力.研究显示,近年来厦门市冬季PM2.5污染有明显减弱趋势,但不利的气象条件和外来污染输入仍会造成PM2.5污染的发生.
文摘This study investigates word recognition processes and strategies of intermediate learners of Chinese as a Second Language (CSL) in contextual reading settings. Two intermediate CSL learners were chosen as research participants, and think-aloud methods and retrospective interviews were used to collect data. The data were analyzed by using Moustakas' data analysis procedure, CresweU's three steps and Bogdon and Biklen's data analysis methods. Results indicated that intermediate CSL learners go through different processes of word recognition as it might be automatic, based on context, pronunciation, previous knowledge and the meaning of characters, or, in case of word recognition failure, skipping the words or skipping them but reading them again later; and their word recognition strategies in contextual reading settings mainly include cognitive strategies and self-regulatory strategies. Among these strategies, cognitive strategies consist of direct transformation, translation, interpretation, guessing, inferring and finding key words; and self-regulatory strategies include metacognitive strategies, behavior regulating strategies, emotion regulating strategies and motivation regulating strategies. A model of intermediate CSL learners' word recognition strategies can be constructed based on the results. The present study provides both theoretical and pedagogical implications in the field of CSL vocabulary acquisition and teaching.