基于非线性渗流模型采空区漏风流场数值模拟

针对采空区非线性渗流模型中颗粒平均粒径的取值问题,利用专业的流体力学软件fluent对刘庄矿151305工作面采空区不同颗粒粒径下的漏风流场进行了模拟,以此确定合适的平均粒径,并利用该采空区颗粒平均粒径对工作面供风量及采空区漏风的影响进行了模拟与分析。结果表明,采空区内平均粒径的取值对工作面风量分布影响较大,瓦斯抽采负压也相差一个数量级;通过与实测工作面风量及实际的瓦斯抽采负压作对比,当采空区颗粒平均粒径取0.1 m时,模拟结果与现场实际最为吻合;工作面供风量越大,采空区的漏风量也越大,两者为二次函数关系。该研究方法为工作面采空区漏风流场数值模拟提供了理论指导。     

北京地区地表水中OCPs和PCBs的污染分析

在夏、冬两季对北京地区密云,潮白河,玉渊潭和通惠河等地表水中17种有机氯农药（OCPs）和84种多氯联苯（PCBs）的含量进行了分析及来源解析.实验结果表明,OCPs总量在7.86～53.1ng/L之间,平均值为（16.9±14.6）ng/L.PCBs总量在2.99～32.7ng/L之间,平均浓度为（10.9±10.4）ng/L.HCHs,硫丹,DDTs和HCB是主要的OCPs污染物,其含量分别为（13.9±11.5）ng/L,（2.20±2.01）ng/L,（0.63±1.51）ng/L和（0.12±0.14）ng/L.α-HCH/γ-HCH平均比值为1.53,小于工业HCH中比值4～7,表明北京地区地表水中存在林丹的使用.而DDT/（DDD+DDE）比值<1.22,表明北京地区并无新的DDTs污染源输入环境.PCBs以低氯代联苯为主,其中二氯,三氯,四氯和五氯联苯总和占∑₈₄PCBs总量的79.2%.北京地区地表水中不同氯取代数PCBs组成与我国历史PCB产品组成相符,均以低氯代联苯为主,表明北京地区地表水中PCBs污染来源为历史使用.相比于国内其他区域水质而言,北京地区地表水OCPs和PCBs污染水平较低.     

Geochemical speciation and risk assessment of metals in the river sediments from Dan River Drainage,China

This study investigates the partitioning of metals in surface sediments from the Dan River drainage basin, the source of drinking water for the South to North Water Transfer Project, China, to determine their bioavailability and associated levels of risk. Sediment samples were collected from 99 sites along the Dan River, and the concentration of each element fraction was determined using sequential extraction and inductively coupled plasma-mass spectrometry. The residual fraction was the major phase for most metals sampled. Among the non-residual fractions, greater proportions of Zn, Mn and Cd were transported in in the available phase, whereas Ba, Sb, Pb and As were mainly found in the reducible phase. The oxidisable phase was important for the transport of Ni, Co, Cr and Cu in sediments. This analysis of sediments from the Dan River basin indicates a very high risk of pollution from Cd, Co, Mn, Sb and Zn. Combined with the sediments with extremely high concentrations, the Dan, Laoguan and Yinhua rivers, which have been affected by ore-mining activities, pose a very high risk to the surrounding areas and should be the subject of future studies.     

Solid phase extraction of Cu (II), Ni (II), Co (II), and Fe (III) ions in water samples using salicylaldehyde benzoylhydrazone on Amberlite XAD-4 and their determinations by flame atomic absorption spectrometry

A multi element preconcentration procedure for solid phase extraction on Amberlite XAD-4 as their salicylaldehyde benzoylhydrazone chelates and flame atomic absorption spectrometric determination of some trace metal ions in water samples are proposed in this work. The influences of some analytical parameters, including pH of aqueous solution, amounts of reagent, flow rates of sample and eluent solutions, and sample volume on the quantitative recoveries of copper, nickel, cobalt, and iron were investigated. The effects of concomitant ions on the retentions of the analytes were also examined. The developed method has been successfully applied to the determination of metal ions in some real samples, including, tap water, river water, spring water, and waste water.     

基于改性石墨烯固相萃取-液相色谱法测定联苯菊酯

以石墨粉末为原料通过Hummers法逐步合成磁性胺基化石墨烯(Fe3O4-NH2-G),分别用扫描电镜和FTIR对其表面形貌和化学结构进行表征,并对Fe3O4-NH2-G用于实际样品中联苯菊酯的吸附性能进行了研究.以高效液相色谱为检测手段,对洗脱液和淋洗液的选择、萃取时间和洗脱时间、离子强度、溶液p H、吸附剂总量等相关参数进行优化.实验结果表明,用1%乙酸乙腈溶液做洗脱液,50%甲醇水溶液作为淋洗液,吸附时间洗脱时间都是20 min,溶液p H值为7,不加Na Cl时吸附效果最好.在293 K下改性石墨烯的平衡吸附量136 mg·g-1.实验表明最优条件下检出限达到1.7 ng·m L-1,线性范围为0.005—10μg·m L-1,方法对实际样品的加标回收率91.8%—101.6%,可应用于痕量联苯菊酯的测定.该实验研究表明Fe3O4-NH2-G对联苯菊酯有很好的吸附能力.     

基于因子分析的开采层瓦斯抽采方法选择

基于煤与瓦斯的七个基本参数,应用因子分析方法,得到了反应本煤层抽放难易程度、突出危险性及瓦斯涌出量(不考虑邻近层影响)的三个因子。依据因子得分对开采层瓦斯抽放难易程度及煤与瓦斯突出危险性进行了分类,进而对开采层瓦斯预抽方法进行判断。结果表明,采用因子分析的方法进行开采层瓦斯预抽方法的选择与现场抽放设计基本一致,并且对于传统方法无法分类的情况也给出了合理的分类判断。采用该方法可以较客观、合理的选择开采层瓦斯抽采方法。     

深孔预裂爆破在深井高瓦斯低透气性煤层瓦斯抽采中的应用

为解决潘一东矿深井低透气性高瓦斯煤层瓦斯抽采率低的问题,提出了运用深孔预裂爆破技术提高煤层透气性,进行瓦斯预抽,进而提高瓦斯抽采率,降低煤层突出危险性的方法。通过数值模拟阐述了深孔预裂爆破技术的作用机理,并对潘一东矿应用效果进行了现场考察。研究表明:在低透气性煤层实施深孔预裂爆破技术后,煤层透气性得以提高,平均瓦斯抽采量提高了3倍,有效地提高了瓦斯抽采率,降低了煤体瓦斯压力和含量,从而在一定程度上降低了煤与瓦斯突出的危险性。     

海岸带表层沉积物中磷的地球化学特征

通过连续提取法对莱州湾主要入海河流及近岸海域表层沉积物中5种形态磷进行了定量分析.结果表明,近海沉积物自生钙结合磷含量(45.6%)高于河流(37.3%),而铁结合磷(Fe-P)含量(18.2%)却低于河流(31.3%).在近海,可交换或弱结合磷含量和粉砂比例呈正相关,表明该形态磷主要吸附于细粒粉砂．河流沉积物Fe-P与Fe浓度呈显著正相关(P<0.01),表明河流沉积物Fe-P分布受沉积物活性铁含量的控制．河口处Fe-P普遍低于相应河流,这可能与海相泥沙输入及河口厌氧区硫酸盐还原或硫化物累积有关.近海沉积物总可提取态磷平均浓度总体呈现出由海洋向河口方向递减的趋势.     

全自动固相萃取-超高效液相色谱串联质谱法测定地表水中18种头孢菌素

建立了超高效液相色谱串联质谱（UPLC-MS/MS） 法测定地表水中18种头孢菌素的方法。采用全自动固相萃取技术进行前处理,地表水样经HLB固相萃取小柱富集后,用10%（V/V）的甲酸溶液（溶剂为甲醇）洗脱。优选BEH Shield RP18（1.7μm,2.1mm×100mm） 色谱柱进行分离,在电喷雾正离子（ESI+）模式下电离,多反应模式（MRM）下检测,外标法定量。结果表明：18种头孢菌素在5.0～100 μg/L 范围内线性关系良好,相关系数（r）均＞0.999,方法检出限为0.5～1.8 ng/L,测定下限为2.0～7.2 ng/L。对地表水样品进行加标回收实验,18种头孢菌素的相对标准偏差（RSD）为0.5%～14.5%,加标回收率为64.3%～92.8%。该方法自动化程度高,结果稳定可靠,适用于地表水中头孢菌素的测定。     

Field evidence of decreased extractability of copper and nickel added to soils in 6-year field experiments

The phytotoxicity of added copper (Cu) and nickel (Ni) is influenced by soil properties and field aging. However, the differences in the chemical behavior between Cu and Ni are still unclear. Therefore, this study was conducted to investigate the extractability of added Cu and Ni in 6-year field experiments, as well as the link with their phytotoxicity. The results showed that the extractability of added Cu decreased by 6.63% (5.10%–7.90%), 22.5% (20.6%–23.9%), and 6.87% (0%–17.9%) on average for acidic, neutral, and alkaline soil from 1 to 6 years, although the phytotoxicity of added Cu and Ni did not change significantly from 1 to 6 years in the long term field experiment. Because of dissolution of Cu, when the pH decreased below 7.0, the extractability of Cu in alkaline soil by EDTA at pH 4.0 could not reflect the effects of aging. For Ni, the extractability decreased by 18.1% (10.1%–33.0%), 63.0% (59.2%–68.8%), and 22.0% (12.4%–31.8%) from 1 to 6 years in acidic, neutral, and alkaline soils, respectively, indicating the effects of aging on Ni were greater than on Cu. The sum of ten sequential extractions of Cu and Ni showed that added Cu was more extractable than Ni in neutral and alkaline soil, but similar in acidic soil.

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