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61.
为了简化多环芳烃(PAHs)的Koc、Kow和BCF等活性参数的测定和预测工作,通过对PAHs的活性参数与气相色谱保留指数(I)、苯环个数(N)的相关关系分析,分别建立了I与lgKoc、lgKow和lgBCF,N与lgKoc、lgKow和lgBCF间的2类一元线性回归预测方程,以及I、N与lgKoc、lgKow和lgBCF间的二元线性回归预测方程。结果表明,PAHs类化合物的I值或N值分别与lgKoc、lgKow和lgBCF存在明显的线性相关性,均能对上述3种活性参数进行准确预测,其中,用I值建立的一元回归方程的预测精度更好;而利用I值和N值共同建立的二元预测方程经t检验发现,方程中变量N的偏回归系数的统计检验没有显著意义。本研究利用I值建立的一元线性预测模型能较好地预测PAHs类化合物的Koc、Kow和BCF等活性参数,从而为PAHs的活性参数预测提供了一种简便易行的方法。  相似文献   
62.
建立了一种以SYBR Green Ⅰ为结合染料、快速准确检测转抗除草剂基因成分的实时荧光定量PCR方法.以转基因大豆与转基因玉米标准品为材料,通过使用特异性引物和SYBR Green Ⅰ结合染料实时荧光定量PCR技术,对转基因农作物中外源抗除草剂基因进行了定量检测,绘制了两种基因扩增的标准曲线图,根据标准曲线方程计算外源基因含量;并作了溶解曲线、检测方法检测灵敏度和精密度的分析.研究发现,两者标准曲线方程线性关系良好.R~2 值分别达到0.993 9与0.992 4.通过已知标准品进行验证,实测值与真值接近,与实际含量的相埘偏差是6.52%和7.90%.结果表明,SYBR Green Ⅰ结合染料法完全可以用于转基因农作物定量PCR检测.图5表2参11  相似文献   
63.
In 2010 the Gulf Coast experienced the largest oil spill affecting U.S. waters in history. Evaporating crude oil and dispersant chemicals can cause major health problems. This paper examines the impact of the Deepwater Horizon oil spill on air quality and infant health outcomes. Using U.S. Environmental Protection Agency (EPA) AirData, vital statistics data from National Center for Health Statistics (NCHS), and a difference-in-difference methodology, we find that the oil spill of 2010 increased concentrations of PM2.5, NO2, SO2, and CO in affected coastal counties, increased incidence of low birth weight (<2500 g) and premature born infants (<37 weeks of gestation). Heterogeneity effects reveal more pronounced adverse infant health outcomes for black, Hispanic, less educated, unmarried, and younger mothers. Results are robust to a wide range of controls and robustness checks.  相似文献   
64.
为研究室内外PM10中多环芳烃相关性和来源特征,于2009年非采暖季、采暖季在天津市某小区36位住户室内和室外进行PM10膜采样,并分析其中12种PAHs浓度.结果表明,非采暖季较采暖季更为良好的室内外通风性,导致非采暖季室内外PM10中PAHs浓度没有显著差异(P>0.05),而采暖季室内PM10中PAHs浓度显著小于室外浓度;非采暖季室内外PM10中各PAHs占总PAHs的质量百分比基本一致,而采暖季其室内外质量百分比有明显不同;采暖季和非采暖季室内外PM10中PAHs的I/O平均值均低于1,但采暖季I/O值小于非采暖季. 对参与者的时间活动模式分析表明,在采暖季和非采暖季,室内吸烟、清洁活动以及烹饪对室内PM10中PAHs浓度变化均没有显著影响(P>0.05). 室内外PAHs浓度线性回归分析表明,室内PM10中5~7环PAHs主要受到室外源的影响,2~4环PAHs主要受到室内源的影响,非采暖季和采暖季室内外PM10中总PAHs的有效穿透因子分别为0.73和0.51. 通过特征比值法对PM10中PAHs来源进行解析得出,燃煤源、柴油机动车是其主要来源.  相似文献   
65.
分别采用黄菖蒲(Iris pseudacorus L.)、狭叶香蒲(Typha angustifolia L.)和铜绿微囊藻(Microcystis aeruginosa)共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明,黄菖蒲在质量浓度大于10 g/L时对初始密度为1.0×107 ind/mL的铜绿微囊藻具有较好的抑制作用,表现为黄菖蒲质量浓度为10、20和40 g/L时,第15天对铜绿微囊藻的抑制率分别为30.1%、51.8%和84.0%;狭叶香蒲在质量浓度大于20 g/L时对铜绿微囊藻有明显的抑制作用,表现为狭叶香蒲质量浓度为20 g/L和40 g/L时,第15天对铜绿微囊藻的抑制率分别为34.2%和77.7%,实验过程中,铜绿微囊藻叶绿素a含量逐渐减少,而藻密度、SOD活性及MDA含量先增加后逐渐降低,表明经过一段时间持续地化感胁迫,黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫,导致细胞结构严重损伤和叶绿素大量分解,从而强烈抑制铜绿微囊藻的生长。  相似文献   
66.
本文通过对医药PG05生产过程中产生的洗柱废液进行气相色谱分析,建立了洗柱废液二氯甲烷、甲醇的色谱分析条件,并且进行定性、定量的分析,从而达到重新利用的目的.该方法已在东北制药总厂三分厂应用.  相似文献   
67.
出露于新疆西准噶尔北缘萨吾尔山北坡哈尔交一带的哈尔交岩体和阔依塔斯岩体同时形成于早二叠世的拉张环境,但地质、地球化学特征存在明显差异。前者Na2O K2O、Zr、Hf偏高,Rb、Sr、Nb、Th、Rb/Sr、Rb/Ba偏低,∑REE=99.66~249.47,平均为177.08,δEu=0.66~0.77,平均0.72。与区内华力西中期形成的“I”型花岗岩中的到性岩地球化学特征相近,为“I”型花岗岩;后者富硅、碱、高∑REE,低Ca、Mg、Al,δEu=0.15~0.23,与典型“A”型花岗岩地球化学一致。两种不同成因类型花岗岩是在碰撞造山之后的应力松弛阶段,随着扩张程度的不断增强,岩浆向着硅、碱和稀土元素含量增加的方向演化过程中不同阶段的产物。  相似文献   
68.
PAHs and PCBs were collected simultaneously indoors and outdoors at eight non-smoking homes located in four buildings in high-traffic areas of Rome. The purpose was to evaluate the relevance of indoor air in contributing to the overall exposure of the urban population. The vertical distribution was also investigated by collecting outdoor samples at both road and roof level, and indoor samples in both a high and a low floor flat of each building. At one coal-heated building, samples were collected during both the heating and the non-heating season. No evident PAH source was present indoors. Indoor and outdoor daily concentrations of benzo[a]pyrene (BaP) ranged, respectively, 0.1–4.6 ng m−3 and 0.7–2.3 ng m−3. With the heating on, indoor PAH concentrations equalled or exceeded those outdoors, with BaP indoor/outdoor ratios up to 4; during the warm season, ratios decreased to 0.2–0.6. Indoor PAHs at the low floors exceeded the high-floor ones when the heating was off (vehicle exhausts being the dominant source), while being equal or lower with the heating on; the vertical gradient of indoor PAHs between different floors was within a factor of 2. Outdoor PAHs at roof level were 20–70% of those at road level, which in turn exceeded those at the medium-traffic station up to a factor of 4. The outdoor concentrations of Σ6 indicator PCBs ranged 0.1–1.6 ng m−3. Indoor PCB concentrations exceeded those outdoors by an approximate factor of 2–50. No vertical gradient was observed. The results indicated that indoor air may contribute to the overall exposure to PAHs and PCBs more than the urban air. They were also consistent with recent findings suggesting that indoor air can be a relevant source of PCBs for outdoor air.  相似文献   
69.
This paper develops and applies an integrated model of mortality and morbidity valuation that is consistent with the principles of welfare economics. To obtain the integrated model, the standard one-period expected utility model of one person facing the prospect of either being alive or dead is extended to incorporate (1) a third health state (sick) with a utility level that is intermediate to utility if healthy and utility if dead, (2) a family perspective in which a parent makes choices about risk exposure both for herself and for a child, and (3) a multi-period framework that allows for possible parent/child differences in illness latency. Monetary benefits of health risk reduction obtained from the integrated model are compared with those that would be computed using the standard model. The integrated model then is applied using data obtained from two field studies of skin cancer and leukemia to demonstrate how it can be used to estimate health benefits of reduced illness and death risks.  相似文献   
70.
Measurements of indoor and outdoor PM10, as well as indoor O3 and CO concentrations were conducted and are presented here. These measurements were carried out at an institute building, located in a suburban industrial area in Greece. Both indoor and outdoor PM10 samples were also collected and their elemental composition was identified by ED-XRF analysis. Twenty seven major, minor and trace elements were identified. The measurements took place generally in different periods of institute operation, from June 2004 to February 2005. The indoor PM10 concentrations which were measured during the normal operation period of the institute were found to be many times higher than the respective outdoor PM10 concentrations of the same periods. On the contrary, the indoor PM10 concentrations which were measured during the holiday period were found to be lower than their corresponding outdoor values. Indoor O3 and CO concentrations were found to be in low level. Indoor PM10 concentrations were found to be in a relative good correlation with O3 (r = 0.45) and in high correlation (r = 0.98) with CO concentrations. On average, total elements concentrations were much higher indoors relative to outdoors. Based on above findings we attempted to determine the pollution sources of the indoor environment and to investigate some parameters or chemical processes that affect indoor pollutants’ levels.  相似文献   
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