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91.
用高铝陶瓷球磨加工在120℃下烘干30h的风砂土、黑土和暗棕壤土壤样品。用X-射线荧光光谱法等分析样品中Cu,F3,Ti等元素,做均匀度检验,结果表明样品均匀。定值分析采用NA、ICP-MS等18种不同原理的分析技术。在1年多时间里,用X-射线荧光光谱法做稳定性实验,表明样品稳定。在IBM计算机上处理获取的全部数据。用Grubbs、多重比较S法等剔除离群值,求出最佳估计值。以最佳估计值按定值原则确 相似文献
92.
93.
Characterization and distribution of polycyclic aromatic hydrocarbon in sediments of Haihe River, Tianjin, China 总被引:7,自引:0,他引:7
JIANG Bin ZHENG Hai-long HUANG Guo-qiang DING Hui LI Xin-gang SUO Hong-tu LI Rui 《环境科学学报(英文版)》2007,19(3):306-311
In this study sediment samples were collected from 13 sites of Haihe River in Tianjin City, China, sixteen of priority polycyclic aromatic hydrocarbons (PAHs) listed in USEPA were analyzed by means of GC-MS. The total concentrations of PAH ranged from 774.81 to 255371.91 ng/g dw, and two to four rings of PAHs were dominant in sediment samples. Molecular ratios, such as phenanthrene/anthracene, fluoranthene/pyrene and low-molecular-weight PAH/high-molecular-weight PAH, were used to study the possible sources of pollution. It indicated a mixed pattern of parolytic and petrogenic inputs of PAHs in sediments in Haihe River. The petrogenic PAHs may be mainly derived from the leakage of refined products, e.g., gasoline, diesel fuel and fuel oil vehicle traffics or gas stations from urban area. The pyrolytic PAHs might be from the discharge of industrial wastewater and the emission of atmospheric particles from petrochemical factories. In addition, the levels of PAHs in the urban and industrial areas are far beyond the values reported from other rivers and marine systems reported. This situation may be due to polluted discharging from some petrochemical industrial manufactories and worse traffic conditions in Tianjin. 相似文献
94.
Start-up performances of dry anaerobic mesophilic and thermophilic digestions of organic solid wastes 总被引:6,自引:0,他引:6
Two dry anaerobic digestions of organic solid wastes were conducted for 6 weeks in a lab-scale batch experiment for investigating the start-up performances under mesophilic and thermophilic conditions. The enzymatic activities, i.e., β-glucosidase, N-α-benzoyl-Largininamide (BAA)-hydrolysing protease, urease and phosphatase activities were analysed. The BAA-hydrolysing protease activity during the first 2-3 weeks was low with low pH, but was enhanced later with the pH increase. β-Glucosidase activity showed the lowest values in weeks 1-2, and recovered with the increase of BAA-hydrolysing protease activity. Acetic acid dominated most of the total VFAs in thermophilic digestion, while propionate and butyrate dominated in mesophilic digestion. Thermophilic digestion was confirmed more feasible for achieving better performance against misbalance, especially during the start-up period in a dry anaerobic digestion process. 相似文献
95.
HAN Hai-yan HUANG Guo-dong JIN Shun-ping ZHENG Pei-chao XU Guo-hu LI Jian-quan WANG Hong-mei CHU Yan-nan 《环境科学学报(英文版)》2007,19(6):751-755
Ion mobility spectrometry (IMS) is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions (H2O)nH^+ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1- propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions (H2O)nH^+. The mixture of these alcohols, including two isomers, has been detected, and the results showed that they could be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional ^63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L. 相似文献
96.
Number concentration and size distributions of submicron particles in Jinan urban area: Characteristics in summer and winter 总被引:1,自引:0,他引:1
GAO Jian WANG Jin CHENG Shu-hui XUE Li-kun YAN Huai-zhong HOU Lu-jian JIANG Yu-quan WANG Wen-xing 《环境科学学报(英文版)》2007,19(12):1466-1473
The aerosol number concentration and size distribution were measured with the newly developed Wide-range Particle Spectrometer in summer and winter of 2006 at the urban site of Jinan City.Here reported the characteristics of fine particles of the different observation seasons.Relative high number concentrations for the particles in the diameter range of 10-500 nm were observed in both seasons.It was found that the dominant number distributed in particle diameter smaller than 100 nm and the percentage over the number concentration of all air particles is much higher than what has been measured in other urban sites over the world.The number mean diameter in summer was much smaller than in winter,strongly suggesting the different origin of ultrafine particles in different seasons.That is, particles in ultrafine mode mainly came from nucleation and new particle formation in summer while from traffic emission in winter. The diurnal variation also supported this point.Number concentration in the diameter range of 10-200 nm got their peak values at noontime,well correlated with the mixing ratio of SO_2 and the intensity of solar radiation in summer.While in winter,those in the same diameter range showed the main peaks during the traffic hours happened in the morning and evening. 相似文献
97.
Yann Devos Pieter Maeseele Dirk Reheul Linda Van Speybroeck Danny De Waele 《Journal of Agricultural and Environmental Ethics》2008,21(1):29-61
Via a historical reconstruction, this paper primarily demonstrates how the societal debate on genetically modified organisms
(GMOs) gradually extended in terms of actors involved and concerns reflected. It is argued that the implementation of recombinant
DNA technology out of the laboratory and into civil society entailed a “complex of concerns.” In this complex, distinctions
between environmental, agricultural, socio-economic, and ethical issues proved to be blurred. This fueled the confusion between
the wider debate on genetic modification and the risk assessment of transgenic crops in the European Union. In this paper,
the lasting skeptical and/or ambivalent attitude of Europeans towards agro-food biotechnology is interpreted as signaling
an ongoing social request – and even a quest – for an evaluation of biotechnology with Sense and Sensibility. In this (re)quest, a broader-than-scientific dimension is sought for that allows addressing the GMO debate in a more “sensible”
way, whilst making “sense” of the different stances taken in it. Here, the restyling of the European regulatory frame on transgenic
agro-food products and of science communication models are discussed and taken to be indicative of the (re)quest to move from
a merely scientific evaluation and risk-based policy towards a socially more robust evaluation that takes the “non-scientific”
concerns at stake in the GMO debate seriously. 相似文献
98.
基于土地利用变化的生态服务价值损益估算--以大庆市为例 总被引:21,自引:0,他引:21
土地利用/覆盖变化遥感研究表明,大庆市自1988年以来土地利用状态变化很大,由此引起了该区域生态环境的一系列响应及其生态系统服务价值的变化。以大庆市1988年和2001年的Landsat TM图像解译数据为基础,应用Costanza等人对全球生态系统服务价值的测算方法,分析了该市土地利用变化及其所引起的生态系统服务价值的变化。研究结果表明,13年间,大庆市土地利用的变化损害了该区域生态系统的生态服务功能,使生态系统服务价值损失了20.76%-24.01%。 相似文献
99.
J.??áslavskyEmail author P.?Kotla?íková K.?Bene?ová 《Environmental Chemistry Letters》2004,2(2):89-92
Semipermeable membrane devices (SPMDs) are nowadays used as passive samplers of organic pollutants. The knowledge of the sampling rate values (RS) of each substance trapped on membranes is necessary to calculate their average concentration. Here we calculate RS values for 16 polycyclic aromatic hydrocarbons using the comparison of active sampling method results and the amounts sequestered by SPMDs at varying exposure times.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organized by Dr. Branimir Jovancicevic. 相似文献
100.
The presence of Whitethroats and their potential invertebrate prey in farmland trees and shrubs was investigated. The management of this vegetation by farmers, and their motivation for that management, was explored using participatory techniques. Whitethroats were associated with Guiera senegalensis, the shrub species which supports most caterpillars and spiders. Farmers reported declines in trees and shrubs since the 1950s, loss of fallow areas, declines in soil fertility and crop yields, and increases in the use of fire for clearing fields. Trees are valued by people for their cultural and medicinal uses and some species used by Whitethroats and other birds have potential for restoring soil fertility, although this was not recognised by farmers. More sustainable use of savanna farmland could have both agronomic and wider conservation benefits, and the provision of information that accommodates farmers' cultural and economic incentives could benefit both farmers and wildlife. 相似文献