1957—2012年中国参考作物蒸散量时空变化及其影响因子分析

根据1957—2012年全国608个气象站的逐日气象资料,利用Penman-Monteith公式计算作物潜在蒸散量,对全国及水资源一级分区潜在蒸散量时空分布特征、变化趋势进行分析;基于Arc GIS及SPSS软件,采用主成分分析方法,对潜在作物蒸散量的影响因子及其分布特征进行探讨。结果表明:近56 a来,全国年潜在蒸散量在616~2 128 mm之间,河西走廊、南部岭南地区、海南岛以及华南沿海作物潜在蒸散量较大,而在黑龙江一带、四川盆地及西南地区东部,潜在蒸发量较小。各分区年均潜在蒸发量均呈现减少趋势,西北诸河区倾向率最大,为-12.22 mm/10 a;影响潜在蒸散量的因子中,第1主成分为热力学因子,第2主成分为水分因子和辐射因子,第3主成分为地理因子和空气动力学因子,第4主成分为高程因子。     

黄河流域生态环境脆弱性评价、空间分析及预测

生态环境脆弱性是制约经济可持续、高质量发展的重要因素。以2005—2018年黄河流域73个城市为研究对象,构建了黄河流域生态环境脆弱性的评价指标体系,采用主成分分析计算了黄河流域生态环境脆弱指数,并依据自然断点法将评价结果分为极度脆弱、重度脆弱、中度脆弱、轻度脆弱、微度脆弱五类。进一步通过空间相关分析揭示了黄河流域生态环境脆弱性的时空演变特征,并利用CA-Markov模型对黄河流域2025年生态环境脆弱性进行了预测。结果表明：（1）黄河上、中、下游生态环境脆弱性分别表现“低—中—高”的分布特征,且生态环境脆弱性变化趋势存在区别：上游虽差异较大但波动相似,中游波动方向相反,下游在2016年之后整体呈下降趋势。（2）黄河流域生态环境脆弱性存在空间相关性,上游呈现低—低聚集,下游呈现高—高聚集,中游空间相关性不显著。（3）预测2025年黄河流域中游地区重度脆弱有所扩张,下游地区极度脆弱向中心区域明显收缩。黄河流域生态环境的治理与保护并非一朝一夕之事,也并非某一流域单独能够完成的,黄河上、中、下游要根据不同的自然条件制定与之相适宜、符合整体发展需要的治理与保护措施。     

青岛近岸绿潮区溶解有机质微生物可利用性

以青岛近岸绿潮区水体中DOM （溶解有机质）为研究对象,通过室内降解实验计算了水体中DOC （溶解有机碳）的降解效率并分析了水中CDOM （有色溶解有机质）的荧光组分及其变化特征.结果显示,绿潮区不同站点和暴发前后水体中的DOC均发生了不同程度降解,降解过程符合一级降解动力学方程,其中约8.93%~45.10%的DOC可被微生物利用,在时空上受浒苔绿潮影响程度大的水体中DOC降解率最高.应用三维荧光光谱和平行因子相结合的技术,分析确定了绿潮水体中的CDOM包含3种类腐殖质组分（C1、C2、C3）和1种类蛋白质组分（C4）,且所有样品中类蛋白质组分含量均显著高于单一类腐殖质组分,表明浒苔绿潮释放的CDOM主要成分是类蛋白质.降解实验中,类蛋白质组分的变化与DOC含量降解趋势相同,而类腐殖质组分逐渐增加.同时,CDOM各荧光参数与微生物可利用性DOC百分比含量（BDOC%）相关性分析的结果和支持向量机的权重分析结果均显示：相对于BDOC%,C4组分为正相关,C1组分负相关,表明BDOC与CDOM组分间的关联度极高,可推测类蛋白质与BDOC均易被微生物降解利用,而类腐殖质与RDOC （惰性溶解有机碳）关系更为密切.该研究揭示了浒苔绿潮生消期间水体中DOM含量的变化及其与不同荧光组分的对应关系,可为解释浒苔绿潮造成的次生生态灾害的原因提供理论基础,并且可利用CDOM组分含量和DOC含量快速推测出BDOC的含量,为海洋现场调查提供便利.     

Source identification, contamination status and health risk assessment of heavy metals from road dusts in Dhaka, Bangladesh

In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90, BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7 (municipal waste dumping) and 8 (medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5 (Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9 (urban), 10 (sub-urban), 11 (rural) while sites-7 and 8 (urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites-7 and 8. Values of incremental lifetime cancer risk were from 10⁻⁹ to 10⁻¹¹ showed no carcinogenic health risk by road dusts contaminated with the heavy metals.     

氢化物发生-原子荧光法测定废气中的锡

运用氢化物发生-原子荧光法测定废气中锡的含量,选择了更高效、安全的硝酸-双氧水电热板消解体系对样品进行前处理,调节最佳仪器参数进行测定。研究表明：在0-10μg/L线性范围内,曲线相关系数可以达到0.999 6,方法检出限为0.003μg,加标回收率在92.7%-95.9%之间,RSD≤2.1。氢化物-原子荧光法测定废气中的锡,方法灵敏度高,干扰少,线性范围宽,操作简单、快捷。     

Spectral tests of randomness for spatial point patterns

We develop a spectral framework for testing the hypothesis of complete spatial randomness (CSR) for a spatial point pattern. Five formal tests based on the periodogram (sample spectrum) proposed in Mugglestone (1990) are considered. A simulation study is used to evaluate and compare the power of the tests against clustered, regular and inhomogeneous alternatives to CSR. A subset of the tests is shown to be uniformly more powerful than the others against the alternatives considered. The spectral tests are also compared with three widely used space-domain tests that are based on the mean nearest-neighbor distance, the reduced second-order moment function (K-function), and a bivariate Cramér-von Mises statistic. The test based on the scaled cumulative R-spectrum is more powerful than the space-domain tests for detecting clustered alternatives to CSR, especially when the number of events is small.     

Dynamics, deterministic nature and correlations of outdoor (222)Rn and (220)Rn progeny concentrations measured at Bacău, Romania

The long-term variation, nature and correlations of outdoor ²²²Rn and ²²⁰Rn progeny concentrations measured during the period 1994-2009 were investigated. The time series of data were obtained within the framework of the monitoring program performed by the Environmental Radioactivity Monitoring Station (ERMS) Bac?u, a component part of the National Environmental Radioactivity Survey Network (NERSN), coordinated by National Environmental Protection Agency (NEPA). The measuring method is based on the total beta measurements of atmospheric aerosol filters, using a low background total beta counter and (⁹⁰Sr/Y) reference standard. Analysis of the time series of progeny concentrations in the low atmosphere makes evident different patterns of variation of these concentrations: diurnal, seasonal and annual. A possible relationship of progeny concentration increase with global warming is emphasized. In order to find the dominant frequency of the physical processes determining progeny concentration variability the power spectrum has been used. The deterministic nature of the time series of concentrations has been studied making use of the autocorrelation function and stationarity of the original data and of their phase randomized time series. Also, the correlations with meteorological parameters have been investigated using Pearson’s correlation coefficient with corresponding level of significance.     

我国副省级城市第三产业发展研究——以哈尔滨为例

第三产业发展水平是衡量一个国家经济实力的重要标准，综合评价第三产业，有助于正确认识我国各地区第三产业的发展水平。以我国15个副省级城市为研究对象，构建第三产业综合发展水平指标体系，运用主成分分析法，通过比较分析得出哈尔滨市第三产业发展中存在的问题，并提出相关对策建议。     

Tracing the sources of refractory dissolved organic matter in a large artificial lake using multiple analytical tools

Structural and chemical characteristics of refractory dissolved organic matter (RDOM) from seven different sources (algae, leaf litter, reed, compost, field soil, paddy water, treated sewage) were examined using multiple analytical tools, and they were compared with those of RDOM in a large artificial lake (Lake Paldang, Korea). Treated sewage, paddy water, and field soil were distinguished from the other sources investigated by their relatively low specific UV absorbance (SUVA) values and more pronounced fulvic-like versus humic-like fluorescence of the RDOM samples. Microbial derived RDOM from algae and treated sewage showed relatively low apparent molecular weight and a higher fraction of hydrophilic bases relative to the total hydrophilic fraction. For the biopolymer types, the presence of polyhydroxy aromatics with the high abundance of proteins was observed only for vascular plant-based RDOM (i.e., leaf litter and reed). Molecular weight values exhibited positive correlations with the SUVA and the hydrophobic content among the different RDOM, suggesting that hydrophobic and condensed aromatic structures may be the main components of high molecular weight RDOM. Principal component analysis revealed that approximately 77% of the variance in the RDOM characteristics might be explained by the source difference (i.e., terrestrial and microbial derived) and a tendency of further microbial transformation. Combined results demonstrated that the properties of the lake RDOM were largely affected by the upstream sources of field soil, paddy water, and treated sewage, which are characterized by low molecular weight UV-absorbing and non-aromatic structures with relatively high resistance to further degradation.     

云南省区域人才竞争力研究

随着知识经济社会的进入,人才成为了社会经济发展最为重要的推动因素,不同区域的发展状态越来越决定于其人才的总体实力,即人才竞争力。本文从区域比较的角度出发,构建人才竞争力评价体系和模型,运用主成分分析方法对云南人才竞争力的特征以及在全国的位次进行分析。研究表明,2007年云南省人才竞争力综合得分为-4.4558,在全国31个省区中排名第23位,导致竞争力较弱的主要原因是区域科技活动水平和经济发展水平低。