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101.
中国193个城市规划区土壤微量元素污染与健康风险 总被引:4,自引:4,他引:0
随着城市化进程的加快,城市表层土壤微量元素含量发生了不同程度的变化,城市土壤污染所引发的环境问题进一步凸显.为了系统研究我国31个省(自治区、直辖市)193个地级以上城市规划区表层土壤13种微量元素的含量特征、污染水平和暴露风险,利用地累积指数(Igeo)和综合污染指数(IPI)对土壤微量元素的污染水平进行了评价,采用美国环保署(USEPA)推荐的健康风险评估方法量化了居民暴露于城市土壤的健康风险.研究结果显示:城市规划区表层土壤As、Be、Cd、Co、Cr、Cu、Hg、Ni、Pb、Se、Tl、V和Zn等13个元素含量中位值分别是9.25、2.14、0.174、12.4、68.4、28.2、0.095、27.7、31.1、0.29、0.61、82.7和82.2 mg·kg-1,相比于城市土壤背景值,Cd、Hg和Se是含量变化比较显著的元素.Igeo值表明城市规划区表层土壤污染最严重的是Hg,其次是Se和Cd,污染程度介于无污染至中度污染之间,其他元素无污染.综合污染指数IPIN显示:全国有22个城市规划区土壤已达到重度污染,16个城市达到中度污染,湖南省株洲市是全国土壤污染最严重的城市.健康风险评估结果表明:郴州市、黄石市、株洲市、湘潭市和龙岩市等5个城市规划区土壤暴露对未成年人具有潜在非致癌风险,其中土壤Pb摄入是引发风险的主要因素.建议在综合污染已达中度到重度污染的城市开展详查,摸清土壤污染状况及污染地块分布,建立污染地块清单和优先管控名录,实施污染调控和修复治理. 相似文献
102.
未来升温1.5℃与2.0℃背景下中国水稻产量可能变化趋势 总被引:3,自引:0,他引:3
基于ISI-MIP的5个气候模式在4种RCP情景下模拟输出未来气候数据,筛选未来升温1.5℃和2.0℃的情景数据,依托CERES-Rice水稻模型,模拟升温1.5℃和2.0℃的背景下中国各区水稻产量变化趋势,综合分析未来气候变化特征与水稻产量之间的关系。结果表明:在1.5℃和2.0℃升温背景下,中国平均温度相对于基准时段分别升高1.19℃和1.87℃,平均降水量相对于基准时段分别增加3.07%和6.17%。1.5℃升温背景下中国水稻单产平均减幅7.49%,减产面积占水稻种植总面积的68.6%,严重减产面积占水稻种植总面积的10.3%,其中华南双季稻区单产减幅最大,而东北单季稻区单产增幅最大;2.0℃升温背景下中国水稻单产平均减幅12.02%,减产面积占水稻种植总面积的70.6%,严重减产面积占水稻种植总面积的18.7%,其中华南双季稻区单产减幅仍然最大,而西北单季稻区单产增幅最大。 相似文献
103.
104.
Chi-Chien Kuo Chiou-Ju Yao Te-En Lin Hsu-Che Liu Yu-Cheng Hsu Ming-Kun Hsieh Wen-San Huang 《Die Naturwissenschaften》2013,100(4):379-384
Tail autotomy incurs energetic costs, and thus, a trade-off in resource allocation may lead to compromised immunity in lizards. We tested the hypothesis that tailless lizards will favor constitutive innate immunity responses over an energetically costly inflammatory response. The influence of fasting and colorful ornamentation was also investigated. We experimentally induced tail autotomy in the lizard Eutropis multifasciata and found that inflammation was suppressed by tail loss, but not further affected by fasting; the suppressive effect of colorful ornamentation was manifested only in males, but not in females. Constitutive innate immunity was not affected by any of these factors. As expected, only costly inflammation was compromised, and a less expensive constitutive innate immunity might be favored as a competent first-line defense during energetically demanding periods. After considering conventional trade-offs among tail regeneration and reproduction, further extending these studies to incorporate disease risk and how this influences escape responses to predators and future reproduction would make worthwhile studies. 相似文献
105.
利用海藻酸钠作为包埋剂对苯系物细胞传感器Pseudomonas fluorescens A506(pTS)进行固定化处理,并对细胞浓度、固定化时间、投加量等检测因素进行了优化.固定化后的细胞与游离细胞对苯系污染物的检测效果进行对比.经过2 h固定化处理的细胞传感器,在检测时间1.5~6.0 h内,信号上升速度为游离细胞的2.26倍,信号最大值为游离细胞的2.23倍.固定化处理后的细胞生长缓慢,且浓度远低于游离细胞,说明了固定化处理后的单位细胞信号强度增加.同时,细胞浓度随着固定化时间的延长而降低.在影响因素方面,细胞浓度和固定化时间对于检测信号的影响较大.固定化后,对高浓度的苯系污染物有着更快的信号响应. 相似文献
106.
The effect of preparation parameters on the performance of zeolite for ammonium(20–300 mg N/L) adsorption from simulated wastewater is reported. It was found that the ratios of Na_2O/SiO_2 and Si/Al had a more important influence than crystallization time on zeolite adsorption properties. Relatively low Na_2O/SiO_2 ratios were beneficial for fabrication of zeolites with high proportions of micropore area and volume, which led to the surface adsorption mechanism being dominated by surface free energy and pore effects. However,with decreasing Si/Al ratios, the effect of ion-exchange was more prominent due to the high negative surface potential of zeolite. In addition, the concentration of weak acid sites on the zeolites was increased with lower ratios of Na_2O/SiO_2 and Si/Al, which may promote ammonium removal. Therefore, the most effective zeolite for ammonium removal, which was fabricated at Na_2O/SiO_2= 1.375, Si/Al = 4 and crystallization time of 48 hr, exhibited the cooperative effects of adsorption, ion-exchange and a large amount of weak acid sites. The maximum ammonium adsorption capacity(35.06 ± 0.98 mg/g) and the removal efficiency(94.44% ± 4.00%) were obtained at the dosage of 4.0 g/L zeolite NaX at ammonium concentrations of 300 mg N/L and 20 mg N/L, respectively. The Freundlich isotherm and pseudo-first-order kinetics models provided excellent fitting for the ammonium adsorption process. In addition, zeolite NaX showed about 1.23–3.2 times the ammonium adsorption capacity of clinoptilolite. The stable and efficient reusability of zeolite NaX after five regeneration cycles demonstrated that this adsorbent has considerable potential for practical industrial applications. 相似文献
107.
Ting Kuo Chiang Lin Hsiao-Hsien Chien Jung-Hul Tseng Kuan-Chieh Hsu Chin-Hsien 《Environmental science and pollution research international》2022,29(48):72101-72116
Environmental Science and Pollution Research - The present study aimed to explore the opportunities for the sustainable development of professional sports enterprises and events from the... 相似文献
108.
In recent years, with the raising of awareness in environmental protection and sustainable development in enterprises, the green issue has become more and more critical in supply chain management. This study intends to develop a green supplier selection model which integrates artificial neural network (ANN) and two multi-attribute decision analysis (MADA) methods: data envelopment analysis (DEA) and analytic network process (ANP). It is called ANN–MADA hybrid method. ANN–MADA hybrid method considers both practicality in traditional supplier selection criteria and environmental regulations. It also overcomes traditional DEA drawbacks, limitations of data accuracy and decision-making units (DMUs) amounts constraint. The model evaluation results of an international well-known camera manufacturer indicate that the ANN–MADA hybrid method outperforms two other hybrid methods, ANN–DEA and ANP–DEA. It was also discovered that ANN–MADA has better power of discrimination and noise-insensitivity in evaluating green suppliers’ performances. 相似文献
109.
110.
Fetal cells were enriched from maternal blood using density gradient centrifugation of Histopaque followed by magnetic-activated cell sorting (MACS) to select CD71-positive cells. For each specimen, cells partially purified by Histopaque were split into equal portions, and each portion was subjected to purification by MACS in parallel. Cells before and after MACS were subjected to dual-color fluorescence in situ hybridization (FISH) analysis with X- and Y-chromosome-specific probes. We found that the hybridization rates were decreased by approximately 10% after MACS based on duplicated analysis for each sample. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献