PM10浓度时间序列多时间尺度分析的小波方法

文章利用Morlet小波函数进行小波变换,以乌鲁木齐市的大气污染物时间序列为例,分析了当地PM10的多时间尺度的演变特性。研究结果显示,其年际变化和季节性变化的时间尺度在尺度空间中分布不均匀,受气象和污染源因素影响,具有较明显的局部化特征。     

不同区域城市空气O3和PM2.5累积速率时序模型

利用2017—2018年全国7个区域10个典型城市环境空气O₃和PM_2.5浓度数据,统计污染物累积速率,进而采用回归方法拟合污染物浓度及其累积速率的时间序列模型,分析不同区域污染物时序变化特征差异。结果表明：不同区域O₃浓度时序曲线拟合程度总体高于PM_2.5,石家庄O₃拟合程度最高,西安PM_2.5拟合程度最高。以07：00、14：00分别作为O₃、PM_2.5模拟起点是24 h中的最优模型。不同城市夏季O₃小时浓度时序变化曲线均为单峰形态,O₃浓度及累积速率峰值出现时间可能由城市所处经度决定,太原O₃累积最快,西安O₃消解最快。各城市间冬季PM_2.5小时浓度及其累积速率时序变化曲线形态差异较大,沈阳PM_2.5累积和消解均最快。与浓度相比,城市环境空气O₃和PM_2.5累积速率与光照、扩散条件等有更好的时间相关性。     

膜、柱串联固相萃取-高效液相色谱法测定水中多环芳烃(PAHs)的研究

建立了用膜-柱串联固相萃取(SPE)技术,甲醇和水作为流动相进行梯度洗脱,紫外和荧光检测器串联的高效液相色谱法(HPLC)分析水中EPA优先监控的16种PAHs的方法.     

一种新的时间序列预报方法及其应用

本文叙述了作者提出的时间序列预报方法的基本原理,介绍了这一方法在应用过程中的发展及在实际部门应用的情况,其中包括异常旱涝灾害预报及方法的改进等最新成果。     

MULTIPLICATIVE,SEASONAL ARIMA MODELS FOR LAKE ERIE AND LAKE ONTARIO WATER LEVELS1

ABSTRACT: Federal agencies in the U.S. and Canada continuously examine methods to improve understanding and forecasting of Great Lakes water level dynamics in an effort to reduce the negative impacts of fluctuating levels incurred by interests using the lakes. The short term, seasonal and long term water level dynamics of lakes Erie and Ontario are discussed. Multiplicative, seasonal ARIMA models are developed for lakes Erie and Ontario using standardized, monthly mean level data for the period 1900 to 1986. The most appropriate model identified for each lake had the general form: (1 0 1)(0 1 1)₁₂. The data for each lake were subdivided by time periods (1900 to 1942;1 943 to 1986) and the model coefficients estimated for the subdivided data were similar, indicating general model stability for the entire period of record. The models estimated for the full data sets were used to forecast levels 1,2,3, and 6 months ahead for a period of high levels (1984 to 1986). The average absolute forecast error for Lake Erie was 0.049m, 0.076m, 0.091 m and 0.128m for the 1, 2,3, and 6 month forecasts, respectively. The average absolute forecast error for Lake Ontario was 0.058m, 0.095m, 0.120m and 0.136m for the 1,2,3, and 6 month forecasts, respectively. The ARIMA models provide additional information on water level time series structure and dynamics. The models also could be coordinated with current forecasting methods, possibly improving forecasting accuracy.     

1：1000000中国草地资源图的编制与研究

编制１：１００００００中国草地资源图（以下简称《草地图》）是＂１９７８～１９８５年中国科学技术发展规划＂中的一项重点研究课题。首先在全国约８００万ｋm₂草地分布区的２０００多个县内进行野外实地调查和产草量测定,辅以航、卫片校核,编绘县级１：５万或１：１０万草地类型图、草地等级图、草地利用现状图。然后采用系列制图方法,遵照全国统一的编制规范和制图综合原则,用上述县级草地图逐级缩编成国家级１：１００万草地资源图。该图在不同的制图区域──牧区、半农半牧区、农区有不同的地理要素选择标准;不同的图斑表现级;不同的最小图斑面积。《草地图》除传统地表现草地植被类型外,还表现草地利用性状,按制图单元进行草地等级评价。用变距等高距选取了少量对划分草地类型界线、重要牧草分布界线、季节草地界线有重要指示意义的等高线。     

SB-A型系列造纸白水回收塔应用研究

介绍SB -A型系列造纸白水回收塔的结构、性能及适用的工艺条件 ,实践表明 ,SB -A型系列造纸白水回收塔回收浆料效率高 ,效益显著     

Time series analysis of elemental and isotopic data from biomineralized whale tissue

A temporal record of environmental conditions is often contained within accretionary biological tissue. These records can provide knowledge of the environmental conditions that existed at the time the tissue was formed. In this study, we look at trace element concentrations and isotopic ratios of carbon and nitrogen as contained in baleen from bowhead whales in the eastern and western Arctic Ocean. Time series techniques, including maximum likelihood method and likelihood ratio tests, are applied to analysis of data and inference about their mean structures.     

塔里木及其周边地区的控矿构造、成矿系列和找矿预测──大型、超大型矿床找矿预测之剖析

塔里木是与华北、杨子齐名的中国三大块体之一，是连接中亚与太平洋西岸（中国东部）的桥■，一直为世人所瞩目。作者认为，塔里木板块是在前震旦系结品基底的基础上，主体部分经历了古生代稳定的陆台，中、新生代陆内盆地的演化阶段；边缘部分经历了新元古代一古生代一小生代的陆完增生和相邻洋壳的消亡。在局部地区和某些阶段，由于地壳发展的不均衡，曾发牛过裂谷、裂陷柏和扭壳断裂带。依据这一构造认识划分了赋存于塔里木板块基底构造层、中间构造层、上都构造层、古生代裂谷系、中一新生代超壳断裂排、被动边缘和陆壳增生区小的成矿系列。其中，石油、天然气、钾盐、金刚石、铜、稀有金属、铅、铸和宝玉石等多种矿产均具有非常巨大的找矿潜力。     

State-By-State Carbon Dioxide Emissions from Fossil Fuel Use in the United States 1960–2000

Time series of fossil fuel carbon emissions from 1960–2000 for each of the U.S. states and the District of Columbia are presented and discussed. Comparison of the nationally summarized results with other national datasets shows generally good agreement, usually within 2%, and gives insight into the quality of all the data series. Our extension of the state-by-state emissions estimates back to 1960 reveals patterns of change that are coherent across states and can be related to historic events such as energy crises and federal legislation. Most notable is the changing pattern of coal usage, as coal-producing states produce increasingly more energy (mostly for electricity) for other states so that per capita CO₂ emissions diverge for states that import as opposed to those that export electricity. The decline in carbon emissions from petroleum products following the 1970s is also evident. Per capita emissions range over an order of magnitude for the different states. The data suggest that differences in per capita emissions arise from differences in many technological, physical, resource, social, and economic factors. The data presented here and the few correlations briefly noted pose a challenge for trying to use per capita emissions as a measure of equity or to provide mitigation targets.