自然灾害灾情的熵权综合评价模型

基于熵权理论提出了一种新的灾情综合评价模型.利用福建省2005-2006年主要台风灾害资料,选取受灾面积,成灾面积、受灾人口、死亡人数、倒塌房屋和直接经济损失6个指标对灾情进行评价.结果表明:应用熵权综合评价模型进行自然灾害灾情综合评价,避免了人为的主观任意性,评价结果与实际情况吻合得较好.因而,熵权综合评价模型是一种科学、实用的灾情评价方法.     

Mg2+对克雷伯氏菌NIII2及其诱变菌产絮凝剂特性的影响

研究了Mg2+对克雷伯氏菌NIII2及其诱变株NIII2-1、NIII2-2发酵产絮凝剂特性的影响作用。实验表明,发酵液未外加或投加较少量Mg2+时,3菌株均不分泌黄色物质,且易产酸,致使絮凝剂产量低,小于1.5 g/L。发酵液中加入Mg2+的浓度在0.5~0.7 mmol/L范围,絮凝剂产生时,伴随黄色分泌物出现,发酵液p H稳定在7.5左右,同时絮凝剂产量大大提高,可达9.7 g/L。未投加Mg2+,3菌株所产絮凝剂Zeta电位负值较大,分别为-59.2、-56.6、-52.1 m V,且蛋白质与糖含量比值小于0.5,絮凝活性低;而投加Mg2+所产絮凝剂Zeta电位值可升至-48.0 m V,3菌株所产絮凝剂中蛋白和糖含量比值分别可提高到1.87、3.29、2.03,对高岭土所产生的SS去除率均大于93%。未投加Mg2+时,诱变株NIII2-1、NIII2-2所产絮凝剂含有相当多的O-链接和N-链接的结构,而其他情况下所产絮凝剂则主要是O-链接结构。     

基于GIS空间自相关的江汉平原钉螺分布特征

基于江汉平原1990、1995、2000、2005、2009年5个年份行政村尺度的钉螺面积分布数据,借助ArcGIS软件平台建立了钉螺分布数据库,运用全局自相关、聚类和异常值分析及热点分析方法分析了1990~2009年5个年份的钉螺时空分布特征。结果显示钉螺分布总体上存在显著的空间自相关性,分布模式主要呈现高值聚类,仙桃与洪湖交界处一直都是钉螺分布的高发正热点区域,即钉螺分布面积比较多。从时间变化规律来看,1990、2000和2009年是钉螺分布模式和热点区域发生变化的重要时间节点。研究结果对于钉螺扩散的防控、减少血吸虫病的传播有着重要的理论和现实意义     

Effects of multigenerational exposures of D. magna to environmentally relevant concentrations of pentachlorophenol

The re-emergence of schistosomiasis has given rise to ubiquitous concentrations of the primary control agent pentachlorophenol (PCP) in the environment, especially in the surface waters of China. In this study, the effects of environmentally relevant concentrations of PCP, namely, 0.0002, 0.002, 0.02, 0.2, and 2 μmol/L on survival, age at first reproduction, fecundity, length of mothers, and number of molts of Daphnia magna were studied over three generations. The survival of D. magna exposed to 2 μmol/L was significantly affected in the three generations. Toxic effects were enhanced in later generations. Age at first reproduction of F ₁ and F ₂ D. magna was significantly slower than that of the controls. The total number of offspring per female exposed to concentrations of 0.002 μmol/L or greater was less (23.5 to 67.6, 9.4 to 73.7, and 3.6 to 83.7 %) than that of the controls in the F ₀, F ₁, and F ₂ generations, respectively. The body length of mothers significantly decreased (4.7 to 6.8, 9.6 to 15.1, and 13.3 to 23.2 %) after exposure to 0.002 μmol/L or greater than those of unexposed individuals in the F ₀, F ₁, and F ₂ generations, respectively. Dose–response relationships between concentrations of PCP and length and number of molts of D. magna were observed in the F ₀ to F ₂ generations. PCP concentrations on the surface waters of China caused adverse effects to D. magna, which increased over successive generations. Significant effects were observed in the third generation. The multigenerational studies were more sensitive than the single-generation experiments. Thus, multigenerational exposure may be more predictive of chronic exposure under field conditions.     

柠檬酸淋洗去除电子垃圾污染土壤中的重金属

采用柠檬酸溶液对模拟电子垃圾污染土壤（简称污染土壤）中Cu,Pb,Cd 3种重金属进行淋洗实验,考察了柠檬酸溶液的浓度、柠檬酸溶液的pH、淋洗时间等对污染土壤中Cu,Pb,Cd的淋洗效果,探讨了柠檬酸溶液淋洗前后污染土壤中Cu,Pb,Cd 3种重金属各形态含量的变化。研究结果表明,在柠檬酸溶液的浓度0.100 mol/L、柠檬酸溶液的pH 5、淋洗时间1 440 min的适宜条件下,对污染土壤中Cu,Pb,Cd的去除率分别达到89.37%,72.11%,86.39%。柠檬酸溶液对3种重金属的去除主要是通过洗出酸可提取态（R1）和酸可还原态（R2）来实现的,每种重金属的R1和R2之和均占到其淋出总量的95%以上,而酸可氧化态（R3）和残渣态（R4）的含量淋洗前后基本无变化。     

Aqueous stabilization of carbon nanotubes: effects of surface oxidization and solution chemistry

Surface oxygen functional groups can affect the morphological characteristics, aggregation kinetics, and adsorption capacity of multi-walled carbon nanotubes (MWCNTs). However, little is known about the quantitative relationship between oxygen content and the dispersion stability of MWCNTs. To investigate the effects of surface oxidization, MWCNTs were oxidized using concentrated H₂SO₄/HNO₃ acids for 0, 1, 2, 4, and 8 h, respectively. Experimental results showed that the oxygen content of MWCNTs increased with surface oxidization time. Linear correlations were found to exist between the oxygen content, critical coagulation concentration (CCC) for NaCl, and critical coagulation pH values of MWCNTs detected by optical density at 800 nm. The CCC values for CaCl₂ increased with oxygen contents for unmodified MWCNTs and lowly oxidized MWCNTs, while which decreased after further increasing the surface oxidization. CCC ratios in the presence of Ca²⁺ to Na⁺ were consistent with the empirical Schulze–Hardy rule for unmodified MWCNTs and lowly oxidized MWCNTs; however, which were much lower than the expected values for highly oxidized MWCNTs. Fulvic acid can clearly increase the stability of MWCNT suspension with unmodified MWCNTs and lowly oxidized MWCNTs, while it cannot affect the dispersion of highly oxidized MWCNTs. This study implied that the oxidation and presence of fulvic acid will possibly increase the mobility, exposure, bioavailability, and toxicity of MWCNTs.     

Metal accumulation by submerged macrophytes in eutrophic lakes at the watershed scale

Metal concentrations (Al, Ba, Ca, K, Li, Mg, Na, Se, Sr and Ti) in submerged macrophytes and corresponding water and sediments were studied in 24 eutrophic lakes along the middle and lower reaches of the Yangtze River (China). Results showed that these eutrophic lakes have high metal concentrations in both water and sediments because of human activities. Average concentrations of Al and Na in tissues of submerged macrophytes were very high in sampled eutrophic lakes. By comparison, Ceratophyllum demersum and Najas marina accumulated more metals (e.g. Ba, Ca, K, Mg, Na, Sr and Ti). Strong positive correlations were found between metal concentrations in tissues of submerged macrophytes, probably because of co-accumulation of metals. The concentrations of Li, Mg, Na and Sr in tissues of submerged macrophytes significantly correlated with their corresponding water values, but not sediment values.     

乙二醇生产废水中特征污染物含量的测定

建立了气相色谱(氢火焰离子化检测器)检测乙二醇生产废水中乙二醇、二乙二醇、三乙二醇含量的新方法。该方法采用HP-FFAP型毛细管色谱柱,优化的色谱条件为:进样口温度230℃,初始柱温50℃,载气流量1.0mL/min,分流比1∶1。在质量浓度为1.0~150.0mg/L范围内,废水中各组分色谱峰面积与浓度呈良好的线性关系,相关系数均在0.9989~0.9996之间;相对标准偏差均小于2.0％;乙二醇、二乙二醇、三乙二醇的最低检出限分别为0.63,0.21,0.25mg/L,加标回收率为97.72％~103.52％。     

水葫芦与厨余垃圾混合好氧堆肥中氮素变化及对腐熟度的影响

通过采用间歇式好氧动态堆肥工艺,对厨余垃圾与添加水葫芦的厨余垃圾进行堆肥实验,探讨堆肥进程中全氮、氨基酸态氮、蛋白质的变化及对腐熟度的影响。结果表明,全氮含量在堆肥后期有所提高,分别由1.76%和2.23%提高到3.64%和2.67%;氨基酸态氮含量与微生物活性显著负相关;添加水葫芦使堆体温度提高,促进了蛋白质的快速降解;堆肥中N素是影响种子发芽的主要因素;添加水葫芦能够促进堆肥的腐熟。     

高炉渣调质作为矿渣纤维原料

以铁矿废石和粉煤灰的混合物为添加剂对高炉渣进行调质,调质后的矿渣作为制备矿渣纤维的原料,并对影响机理进行分析。结果表明,随着添加剂比例升高,矿渣的酸度系数M_k和粘度系数M_η升高,氢离子指数pH降低,矿渣纤维的稳定性逐渐增加,矿渣粘度较小,其主晶相为黄长石。配加添加剂比例较高时熔渣凝固后无矿物析出,形成均匀的无限固溶体。矿渣更加适合制备矿渣棉纤维。