A fractal derivative model to quantify bed-load transport along a heterogeneous sand bed

Environmental Fluid Mechanics - Bed-load transport is a complex process exhibiting anomalous dynamics, which cannot be efficiently described using the traditional advection–diffusion...     

冲裁模压力中心的简化求法

针对某些形状复杂的冲裁件，介绍了一种压力中心的简化求法。     

生态敏感性评价在生态文明建设中的运用研究——以四川省蓬安县为例

以四川省蓬安县为例,基于GIS空间分析技术,结合蓬安当地实际,选取水源涵养、土壤保持能力和生物多样性进行生态敏感性评价,获得蓬安县区域敏感性现状图,并以此为基础构建生态安全格局,该格局注重区域的内在机理与周围的相对联系,保证各生态环境功能区成为具有各自特点、功能和生命活力而又彼此联系的有机体,为其生态文明建设过程中重点领域和重点工程设计规划提供基础支撑,阐明了生态敏感性评价在生态文明建设中的运用,为县级生态文明建设规划做出了贡献.     

The in situ catalytic oxidation of sulfamethoxazole via peroxydisufate activation operated in a NG/rGO/CNTs composite membrane filtration

Environmental Science and Pollution Research - Metal-free carbonaceous composite membranes have been proven to effectively drive novel in situ catalytic oxidation for the degradation of organic...     

Denitrification potential of riparian soils in relation to multiscale spatial environmental factors: a case study of a typical watershed,China

The objective of this study was to test the hypothesis that environmental regulators of riparian zone soil denitrification potential differ according to spatial scale within a watershed; consequently, a second objective was to provide spatial strategies for conserving and restoring the purification function of runoff in riparian ecosystems. The results show that soil denitrification in riparian zones was more heterogeneous at the profile scale than at the cross-section and landscape scales. At the profile scale, biogeochemical factors (including soil total organic carbon, total nitrogen, and nitrate–nitrogen) were the major direct regulators of the spatial distribution of soil denitrification enzyme activity (DEA). At the cross-section scale, factors included distance from river bank and vegetation density, while landscape-scale factors, including topographic index, elevation, and land use types, indirectly regulated the spatial distribution of DEA. At the profile scale, soil DEA was greatest in the upper soil layers. At the cross-section scale, maximum soil DEA occurred in the mid-part of the riparian zone. At the landscape scale, soil DEA showed an increasing trend towards downstream sites, except for those in urbanized areas.     

电子拆解区家禽中溴代阻燃剂的污染特征

对某电子废物拆解区散养草鸡进行了12种多溴联苯醚(PBDEs)和十溴二苯乙烷(DBDPE)的污染水平分析.结果显示,草鸡中PBDEs和DBDPE主要通过土壤途径摄入,各个组织中PBDEs均被检出,肾脏中PBDEs含量最高(2071 ng·g~(-1),以脂重计),肝脏中PBDEs平均含量(550ng·g~(-1),以脂重计)远高于肌肉组织(131 ng·g~(-1)(腿肉)和76 ng·g~(-1)(胸肉),以脂重计),DBDPE主要在肾脏和卵组织中检出.同时,本文对电子拆解区居民通过食用草鸡摄入溴代阻燃剂(BFRs)的健康风险进行了初步评价.结果显示,尽管拆解区居民通过食用草鸡暴露PBDEs和DBDPE的风险处于可接受水平,但综合饮用水、大气呼吸和灰尘摄入等其他暴露途径,BFRs健康风险仍不容忽视.     

氨基化金属有机骨架对废水中新型烟碱类农药的去除机制

为有效去除水中多种新型烟碱类农药(neonicotinoid insecticides, NNIs),通过水热法合成了氨基化金属有机骨架纳米材料(NH₂-MIL-101),结合材料的理化性质表征结果及其对NNIs的吸附性能,探究NH₂-MIL-101对水中NNIs的去除机制。结果表明：NH₂-MIL-101对6-氯烟酸、啶虫脒、噻虫胺、吡虫啉、噻虫嗪的去除率优于MIL-101,最高可达86%、92%、30%、63%、47%,且20 min内可达到吸附平衡;π-π作用和分子空间位阻的不同导致NH₂-MIL-101对不同NNIs的去除存在差异;对于不同NNIs的去除,溶液最佳pH存在差异,综合而言,在pH为3~7时去除效果较好;水中共存阴离子Cl⁻ (0~1 000 mg·L⁻¹)与${\rm{SO}}_4^{2 - }$(0~100 mg·L⁻¹)对5种NNIs的去除效果影响不大,${\rm{HCO}}_3^ - $(0~100 mg·L⁻¹)对NNIs的去除呈现明显的抑制作用。综合上述结果,NH₂-MIL-101对NNIs的吸附符合Langmuir模型和准二级动力学模型,具有良好的吸附效果,且能够重复利用5次,在NNIs的水处理中具有应用价值。     

拉萨河放射性核素238U和232Th分布特征及健康风险评估

为了解拉萨河中放射性核素238 U和232 Th的污染水平及其对人类的致癌风险,利用拉萨河中下游和堆龙曲支流16个采样点水样的238 U和232 Th含量,采取美国环境保护局(U.S.Environmental Protection Agency,US EPA)推荐的放射性核素健康风险评价方法,评估不同年龄人群因饮水途径摄入核素的致癌风险.结果表明,拉萨河中238U和232Th平均活度浓度分别为(2.62±3.46)×10-2 Bq·L-1和(2.3±0.478)×10-3 Bq·L-1,比我国地表水平均值分别高31％和低61.7％;238U和232Th含量沿程分别呈波动稳定和波动变化的趋势;不同人群平均总致癌风险分别为(4.81±4.61)×10-8(幼儿组)、(2.29±1.81)×10-8(少年组)和(3.08±2.13)×10-8 a-1(成年组),均低于1×10-6 a-1(US EPA标准)和我国地表水平均致癌风险值,但对幼儿的致癌危害最大;238U和232Th的致癌风险贡献率随年龄的增长分别下降和上升;建议对羊八井镇附近河水进行持续监测,确保地热资源开发不会造成拉萨河放射性核素的污染.本研究不仅可以为拉萨河放射性核素污染的研究提供参考,而且可以为拉萨河未来的环境保护提供科学依据.