Throughfall chemistry in a spruce chronosequence in southern Poland

The chemical composition of throughfall and canopy leaching, as well as the acid neutralizing capacity and alkalinity depended on the age of Norway spruce (Picea abies Karst) stands and season of the year. A higher amount of sulphur and strong acids was deposited to the soil in the older age classes. Concentrations of SO(4)(2)(-), K(+), H(+), Mn(2+), Fe(2+) and Zn(2+) in throughfall were higher than in bulk precipitation in any season. This suggests that these ions were washed out or washed from the surface of needles and/or barks. The other ions NO(3)(-), NH(4)(+), Ca(2+) and Mg(2+) were retained by the canopy, in particular Ca(2+) and Mg(2+) during the growing season in young stands. Principal component analysis identified five factors responsible for the data structure and suggested the major anthropogenic emission sources were acidic emission (SO(4)(2)(-)+NO(3)(-)), heavy metals-dust particles (Fe(2+)+Mn(2+)+Zn(2+)), ammonium (NH(4)(+)) and H(+), while the natural-origin emission was mineral dust (Na(+)+K(+)+Ca(2+)+Mg(2+)).     

企业安全氛围因子结构和要素组合关系测评研究

总结和分析了国外企业安全氛围测评研究进展,进一步明确安全氛围的概念、内容和研究重点;在参阅文献基础上,设计和开发出适用于国内企业安全氛围量化测评的调查问卷。选择商业企业作为研究样本,以多元统计为理论分析工具,开展实证研究工作;采用探索性因子分析方法提取和选择了商业企业安全氛围的安全需求、安全认识、安全参与、安全地位、安全实施5因子结构及14个关键要素,针对其因子结构和要素组合关系进行了研究和探讨。借助于雷达图形法对研究目标的安全现状给予量化评估,研究的方法和技术路线可为以后的安全氛围诊断模式探究提供参考思路。     

永瓣藤某些化学成分的研究

对永瓣藤总糖、粗脂肪、灰分、维生素C、磷、钾和各类氨基酸的含量进行了测量和分析,并对这些化学成分在不同部位的含量进行了比较。不同部位化学成分的含量存在一定的差异,除灰分外,其它化学成分含量均是叶高于茎、嫩茎高于老茎。     

基于主成分分析法的安徽省生态环境质量研究

人类根据自身的具体要求可对生态环境质量进行评定。研究选择具有代表性、可比性、可操作性的评价指标,运用主成分分析法对安徽省17个地市的环境质量的优劣程度进行了定性、定量分析和判别,为安徽生态省建设和环境管理提供科学依据。     

武汉城市热岛特征及其影响因素分析

正确理解城市热岛效应的形成机制及其影响因素是制定热岛效应缓解政策和研究城市生态问题的前提和基础。选用1987年9月26日的Landsat-5和2013年9月17日的Landsat-8遥感影像进行地表温度反演,分析武汉市城市热岛效应的时空演变特征;对热岛效应明显的武汉市主城区进行格网划分,提取格网内地表温度及所选影响因子指标值,运用主成分回归方法进行地表温度多因子综合分析,探讨城市热岛形成的主要影响因素。结果表明:(1)武汉市地表温度空间分布表现出典型的热岛特征,1987年和2013年分别有27.7%和39.1%的范围被"热岛"覆盖;(2)影响武汉城市热岛效应的主要因素有不透水面指数、水体面积比例、归一化建筑指数、归一化植被指数及绿地面积比例;(3)当其他影响因素稳定时,不透水面指数每增加1%,可使地表温度增温0.04℃~0.10℃;水体面积每增加1%,可降低地表温度0.03℃。     

Source Apportionment of Particulate Matter (PM10) and Indoor Dust in a University Building

A study on source apportionment of indoor dust and particulate matter (PM₁₀) composition was conducted in a university building by using chemometrics. The objective of this study was to investigate the potential sources of selected heavy metals and ionic species in PM₁₀ and indoor dust. PM₁₀ samples were collected using a low-volume sampler (LVS) and indoor dust was collected using a soft brush. Inductively coupled plasma spectrometry (ICP-MS) was used to determine the concentration of heavy metals, while the concentration of cations and anions was determined by atomic absorption spectrometer (AAS) and ion chromatography (IC), respectively. The concentration of PM₁₀ recorded in the building throughout the sampling period ranged from 20 ± 10 μgm^?3 to 80 ± 33 μgm^?3. The composition of heavy metals in PM₁₀ and indoor dust were dominated by zinc (Zn), followed by lead (Pb), copper (Cu), and cadmium (Cd). Principle component analysis (PCA) and multiple linear regression (MLR) showed that the main sources of pollutants in PM₁₀ came from indoor renovations (73.83%), vehicle emissions (16.38%), earth crust sources (9.68%), and other outdoor sources (0.11%). For indoor dust, the pollutant source was mainly earth crust. This study suggests that chemometrics can be used for forensic investigation to determine the possible sources of indoor contaminants within a public building.     

A multivariate statistical analysis of surface water chemistry data--the Ankobra Basin, Ghana

R-mode hierarchical cluster and principal component analysis (PCA) were simultaneously applied to surface water hydrochemical data from three different locations, Ankwaso, Dominase and Prestea, along the Ankobra Basin, Ghana, to extract principal factors corresponding to the different sources of variation in the hydrochemistry, with the objective of defining the main controls on the hydrochemistry at the basin scale. Using the Kaiser criterion, principal components (PC) were extracted from the data and rotated using varimax normalization, for each location. The varimax rotation ensured that variation in the data was maximized for easy interpretation of the results. The analysis reduced 30, 33 and 33 data points, respectively, for Ankwaso, Dominase and Prestea to four, three and four PC representing the sources of variation in the hydrochemistry at the three different locations. Though the PC analysis proved to be more robust at unveiling the sources of variation in the hydrochemistry than the R-mode hierarchical cluster analysis (HCA), the combined use of both techniques resulted in more reliable interpretations of the hydrochemistry. On the basis of these analyses, the hydrochemistry of the basin is controlled largely by the weathering of minerals (silicates, carbonates, gypsum and apatite) from the underlying meta-sediments of the Birimian and Tarkwaian Systems, and the decay of organic matter from the heavily forested regions. Concentrations of the major chemical parameters are within naturally acceptable limits and do not pose threats to the local ecology and humans. There is no strong evidence of high anthropogenic impacts on the major anions and cations used for this research, though there are variations at the different locations studied. The hydrochemistry at Ankwaso is principally controlled by the weathering of silicate minerals, whereas those of Dominase and Prestea are, respectively, influenced by precipitation and domestic wastewaters, and the decay of organic matter.     

东南沿海经济发达地区耕地数量的动态变化及其驱动力研究——以绍兴市为例

东南沿海经济发达地区的耕地变化较为显著,研究该地区耕地变化的趋势与驱动机制,对促进地区经济持续发展具有重要意义.选取绍兴市作为典型案例,探寻该市耕地数量的时空变化特征,并将主成分分析和多元逐步回归分析相结合,揭示该市耕地数量变化的驱动机制.研究结果表明:绍兴市耕地数量变化的时空特征显著,耕地呈现逐年减少的总体趋势;耕地减少以建设占用和以市场为导向的农业结构调整为主,以基本建设投入力度的加大和人们生活收入水平的提高为主要动因.研究结果可为绍兴市合理开发利用有限的耕地资源,促进区域社会与经济的可持续发展提供一定的科学依据,并为进一步研究东南沿海经济发达地区的耕地变化提供借鉴.     

区域水资源承载能力综合评价：主成分分析法的应用

针对模糊综合评判法在综合评价中存在的主观随意性问题,提出采用主成分分析法进行区域水资源承载能力综合评价。首先对各区域的灌溉率、水资源利用率、水资源开发程度、供水模数、需水模数、人均供水量和生态环境用水率这七个主要因素进行了分析;然后,根据主成分分析法的原理,运用少数几个新的综合指标对原来的七个指标所包含的信息进行最佳综合与简化,研究其在各区域水资源开发利用过程中的不同贡献及综合效应;同时,以评价参     

包装装备跌落撞击缓冲特性分析

目的 获得尺寸和质量最小的缓冲结构.方法 基于能量守恒原理,建立包装装备缓冲结构撞击环境缓冲特性理论分析的数学模型,获得正撞和侧撞工况下缓冲结构尺寸和防护效果的变化关系.研究采用新型泡沫填充蜂窝材料的缓冲结构设计,优选泡沫填充蜂窝材料参数.建立缓冲结构撞击环境的物质点法计算模型,开展高速撞击的数值仿真.分析包装装备在撞...