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71.
Nowadays, more people tend to spend their recreational time in large national parks, and trace metal(loid)s in soils have attracted long-term attention due to their possible harm to human health. To investigate the pollution levels, potential sources and health risks of trace metal(loid)s in road soils, a total of eight trace metal(loid)s (including As, Cd, Cr, Cu, Ni, Pb, Zn and Hg) from 47 soil samples along roads were studied in the Huangshan National Park in Southeast China. The results showed that the concentrations of As, Cd, Pb, Zn and Hg appeared different degrees of pollution compared with their corresponding background values. According to the pollution indices, Hg and Cd were recognized as significant pollutants presenting moderate to high ecological risk. Combining principal component analysis and positive matrix factorization model, the results showed that traffic, industrial, agricultural and natural sources were the potential origins of trace metal(loid)s in this area, with contribution rates of 39.93%, 25.92%, 10.53% and 23.62%, respectively. Non-carcinogenic risks were all negligible, while the carcinogenic risk of As was higher than the limit (1 × 10−6). Moreover, children were more susceptible to trace metal(loid)s by ingestion which appeared to be a more important exposure pathway than dermal contact and inhalation. The contribution rates of different sources to non-carcinogenic risks and carcinogenic risks were similar among children and adults, while traffic and industrial sources have a significant impact on health risks. This study will give more insights to control the environmental risks of trace metal(loid)s in national parks.  相似文献   
72.
联合国在2015年发布了可持续发展目标,包含17个目标与169个具体目标,以指导并推动当今时代背景下的可持续发展。随后于2017年发布了包含232个指标的可持续发展目标指标体系,并指出监测工作的开展是促进可持续发展目标落实的重要途径。本文回顾了联合国可持续发展工作的主要历程,体现在可持续发展目标与指标的分离,以及目标体系不断细化两个趋势。为应对不断扩大并细化的可持续发展目标,指标体系也呈现复杂化发展的特征,并使数据需求成为监测工作有效实施的瓶颈。针对数据瓶颈,从复杂指标体系的数据来源、结构特征处理需求、数据整合框架支撑三个方面,剖析并细化了可持续发展目标监测中关于数据供应的挑战。进而提出应从全面性数据来源、多源异构数据处理与融合系列技术、基于地理空间信息的数据管理框架、持续性的数据供应四方面开展针对性研究,以保障可持续发展目标监测工作的实施。  相似文献   
73.
为了确定危险品道路运输安全容量,保障危险品道路运输安全,基于风险理念,使用对比研究方法,提出危险品道路运输个人风险基准,建立改进的危险品道路运输定量风险评估模型。结合提出的风险基准,提出危险品运输安全容量确定方法,解决了单一类别和多种类别危险品运输安全容量确定问题。研究结果表明:在某城市化工集聚区的实例应用该方法,能够大幅度降低危险品道路运输潜在生命损失,有助于保障危险品道路运输安全。  相似文献   
74.
Atmospheric sulfur deposition onto different ecosystems over China   总被引:2,自引:0,他引:2  
The regional acid deposition model system (RegADMS) was applied to simulate the air sulfur deposition onto different landuse types over China, in which the dry deposition velocities of SO2 and sulfate aerosol (SO4(2-) were estimated by use of a big leaf resistance analogy model and the wet scavenging coefficients were parameterized in terms of precipitation rate. Investigations show that the annual total sulfur deposition over mainland China is 7.24mt (1 mt = 10(6) ton) , in which dry deposition and wet deposition accounts for 56 and 44%, respectively. The sulfur deposition onto agriculture land, grass land, and forest land is 1.09, 3.6 and 1.41 mt, respectively, which sums 6.1 mt and accounts for 84% of the total sulfur deposition. The modeled sulfur deposition was in agreement with the measurement conducted at farmland in Yingtan, a typical read soil region in Jiangxi province of China, during the period of November 1998--October 1999. The total sulfur deposition at the Yingtan site is about 10.3 gm(-2) year(-1) of which 83% is dry deposition. The modeling sulfur deposition at the same site is 8.4 g m(-2) year(-1) Furthermore, the comparison between RegADMS and RAINS-ASIA on modeling regional sulfur deposition shows the consistence of the two models. The correlation coefficient between the simulated sulfur deposition at the medium-large cities reaches 0.72.  相似文献   
75.
滑坡变形趋势分析   总被引:3,自引:0,他引:3  
将自回归滑动平均模型引入滑坡变形分析,同时考虑了坡体变形趋势性和波动性对未来变形的影响,使得所建模型能更全面地反映坡体变形的动态。  相似文献   
76.
Bi X  Sheng G  Feng Y  Fu J  Xie J 《Chemosphere》2005,61(10):1512-1522
Cigarette smoke constituents are worthy of concern and characterized as carcinogens. Different experiment conditions may affect the environmental tobacco smoke (ETS) constituents. A study was undertaken in a 75.5-m3 spare office to evaluate ETS constituents in a real environment. Thirty-four volatile organic compounds (VOCs) including three ETS tracers: nicotine, 2,5-dimethylfuran and 3-ethenylpyridine (3-EP), 19 carbonyl compounds, 54 semi-volatile compounds (24 polycyclic aromatic hydrocarbons (PAHs) and 30 alkanes) as well as CO and total particulate matter (TPM) from 15 leading commercial brands were determined. ETS constituents did not increase with increasing cigarette tar. ETS tracers nicotine and 3-EP were affected greatly due to more sorption and surface reactions in real world compared to other studies conducted in chamber, which resulted in 2-5 times lower. Benzene, toluene, ethylbenzene, xylenes, acrolein, 2-butanone and the high molecular weight compounds exhibited little affect. Pearson correlation analyses show that gas-phase and particulate-phase ETS tracers did not show significant correlation, but within each homologue many of compounds correlated significantly. Indole and cholesta-3,5-diene were also detected in ETS. These results may be useful in efforts to better understand the health effect of ETS exposure and source apportionment.  相似文献   
77.
联合国于2015年发布了17个可持续发展目标,为推动其落实,于2017年发布了包含232个指标的指标体系,同时由于其复杂的数据需求,成为可持续发展目标监测工作有效开展的瓶颈。本文针对该指标体系的数据需求,简述了具有可行性的数据供应来源,并以重庆市为例探讨了应对可持续发展目标监测数据需求的数据供应来源。结果发现,跨部门全面性数据需求,成为可持续发展目标监测工作有效实施的重要限制。地理国情普查/监测提供了跨部门数据融合的地理信息数据框架,共享交换平台提供了最为全面的跨部门数据汇聚成果,均成为可持续发展目标监测实施的有效数据供应来源。研究认为,如何发挥现有多类型数据汇聚工作成果优势,针对可持续发展目标监测需求开展数据供应机制研究,应是在实施层面推动监测有效开展的重要方向。  相似文献   
78.
阴霾天气PM_(10)的微观特征及生物活性研究   总被引:2,自引:0,他引:2  
利用高分辨率场发射扫描电镜(FESEM)、图像分析技术(IA),对北京市2004年12月一次严重的阴霾天气条件下采集的PM10(指空气动力学直径小于10μm的颗粒物)的微观形貌、粒度分布、主要颗粒物类型进行了分析,并运用质粒DNA评价法对阴霾和非阴霾天气条件下的PM10样品的生物活性进行了对比研究。结果表明,阴霾天气时PM10样品中以粒度较小的烟尘及其集合体为主,且多呈湿状,含有较多的二次颗粒物,并发现了残余的有机液滴颗粒。质粒DNA实验的结果显示,阴霾天气PM10样品的水溶和全样样品的TD20值(造成20%DNA破坏时所需要的样品剂量)分别为93μg.ml-1和50μg.ml-1,而同一月份非阴霾天气条件下PM10样品的水溶和全样样品的TD20值分别为200μg.ml-1和160μg.ml-1,表明阴霾天气PM10样品比非阴霾天气样品具较强的生物活性,即对人体健康存在着潜在的危害。且无论是阴霾还是非阴霾天气条件下的PM10的全样样品均较水溶样品具更大的生物活性。  相似文献   
79.
In order to characterize the organic properties of waste activated sludge in a wastewater treatment plant,organic matter within sludge was extracted with NH 3 ·H 2 O preferentially,and subsequently fractionated into five fractions using XAD-8/XAD-4 resins.Up to a 63.8%-71.1% of organic matter within the sludge could be efficiently extracted by NH 3 ·H 2 O.Fractionation results showed that hydrophobic acid and hydrophilic fraction were two main components among the sludge organic matter (accounting for 32.2% and 48.0% of the bulk organic matter,respectively),whereas transphilic acid,hydrophobic neutral and transphilic neutral were quite low (accounting for 9.2%,5.8% and 4.8%,respectively).Despite that the extractant of NH 3 ·H 2 O showed a relatively higher extraction efficiency of the aromatic components,the relatively low aromaticity of the organic fractions implied that those non-aromatic components could also be effectively extracted,especially for neutral and hydrophilic fractions.In addition,acidic fractions contained more aromatic humic-like components,whereas the neutral fractions had a greater content of aromatic proteins and soluble microbial byproduct-like components.Extraction of sludge organics with NH 3 ·H 2 O and subsequential fractionation using XAD resins could be a novel method for further characterization of sludge organics.  相似文献   
80.
拓应全 《环境技术》2022,40(1):147-150,156
采用金相显微镜、扫描电镜和拉伸试验机等手段,对复杂环境下电子元器件进行了综合检测和失效原因分析.结果表明,失效电子元器件中铜镁导线材料的化学成分符合规范要求,但是部分单线表面局部分布有不同尺寸横向压痕,不符合规范要求.电子元器件中导线整体在弯扭应力作用下,各单线外侧表面承受较大轴向拉应力;单线在拉应力作用下,极易在表面...  相似文献   
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