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31.
Yongnian Ni Lin Wang Serge Kokot 《Journal of environmental science and health. Part. B》2013,48(4):328-335
A novel differential pulse voltammetry method (DPV) was researched and developed for the simultaneous determination of Pendimethalin, Dinoseb and sodium 5-nitroguaiacolate (5NG) with the aid of chemometrics. The voltammograms of these three compounds overlapped significantly, and to facilitate the simultaneous determination of the three analytes, chemometrics methods were applied. These included classical least squares (CLS), principal component regression (PCR), partial least squares (PLS) and radial basis function-artificial neural networks (RBF-ANN). A separately prepared verification data set was used to confirm the calibrations, which were built from the original and first derivative data matrices of the voltammograms. On the basis relative prediction errors and recoveries of the analytes, the RBF-ANN and the DPLS (D – first derivative spectra) models performed best and are particularly recommended for application. The DPLS calibration model was applied satisfactorily for the prediction of the three analytes from market vegetables and lake water samples. 相似文献
32.
Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building 总被引:2,自引:0,他引:2
This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ15PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM10 (Particulate Matter up to 10 μm in size) bounded Σ15PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ15PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. 相似文献
33.
固定化微生物法去除模拟渗滤液中氨氮的研究 总被引:1,自引:0,他引:1
采用固定化微生物曝气生物滤池(I-BAF)技术成功处理了模拟垃圾渗滤液,探讨了pH和溶解氧(DO)对系统脱氮性能的影响。结果表明,固定化微生物曝气生物滤池反应系统启动迅速,运行稳定,可以有效去除模拟垃圾渗滤液中的有机物和氨氮,其去除率分别达到97.1%和99.9%。在pH为7.5~8.5之间,DO 4.0 mg/L左右的条件下对模拟垃圾渗滤液中氮的去除最为有利,同步硝化反硝化效率以及总氮去除率均达到最高,分别为96.2%和94.3%。这主要是由于I-BAF系统中大孔载体提供了厌氧-兼氧-好氧的微环境,使硝化和反硝化反应在同一个反应器内发生,共同作用实现模拟垃圾渗滤液中总氮的去除。 相似文献
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四川省彭县银厂沟峡谷全长21公里,峡谷和原始森林保存完整。时隐时现的“彩虹”出现于峡谷两岸的瀑布上。区内自然景观丰富多彩。本文根据旅游地质调查工作成果,对自然景观的成因作了初步探讨。 相似文献
36.
Odor and gas release from anaerobic lagoons for treating swine waste affect air quality in neighboring communities but rates of release are not well documented. A buoyant convective flux chamber (BCFC) was used to determine the effect of lagoon loading rate on measured odor and gas releases from two primary lagoons at a simulated wind speed of 1.0 m s(-1). Concentrations of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) in 50-L air samples were measured. A panel of human subjects, whose sensitivity was verified with a certified reference odorant, evaluated odor concentration, intensity, and hedonic tone. Geometric mean odor concentrations of BCFC inlet and outlet samples and of downwind berm samples were 168 +/- 44 (mean +/- 95% confidence interval), 262 +/- 60, and 114 +/- 38 OU(E) m(-3) (OU(E), European odor unit, equivalent to 123 microg n-butanol), respectively. The overall geometric mean odor release was 2.3 +/- 1.5 OU(E) s(-1) m(-2) (1.5 +/- 0.9 OU s(-1) m(-2)). The live mass specific geometric mean odor release was 13.5 OU(E) s(-1) AU(-1) (animal unit = 500 kg live body mass). Overall mean NH3, H2S, CO2 and SO2 releases were 101 +/- 24, 5.7 +/- 2.0, 852 +/- 307, and 0.5 +/- 0.4 microg s(-1) m(-2), respectively. Nitric oxide was not detected. Odor concentrations were directly proportional to H2S and CO2 concentrations and odor intensity, and inversely proportional to hedonic tone and SO2 concentration (P < 0.05). Releases of NH3, H2S, and CO2 were directly proportional (P < 0.05) to volatile solids loading rate (VSLR). 相似文献
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38.
Impact of socioeconomic development on ecosystem services and its conservation strategies: a case study of Shandong Province,China 总被引:1,自引:0,他引:1
Ecosystems and their components provide a lot of benefits for the welfare of human beings. Coupled with increasing socioeconomic
development, most of the rapidly developing and transitional countries and regions have been experiencing dramatic land use
changes. This has resulted in a large amount of forestland, grassland, and wetland being occupied as residential and industrial
land or reclaimed for arable land, which in turn results in a sharp deterioration of ecosystem services around the world.
Shandong Province, an economically powerful province of China, was chosen as a case study in order to capture the impact of
socioeconomic development on ecosystem services. By way of the study, land uses and their changes were categorized between
1980 and 2006, and the ecosystem services capital and changes of 111 counties of Shandong Province in different phases were
evaluated, as well as the total ecosystem services capital, followed by the zoning of ecosystem services function region of
Shandong Province. We found that the counties in mountainous areas and wetlands, where generally the prefectural-level cities
are located with a rapid socioeconomic development, experienced a successive deterioration of ecosystem services especially
during the 2000s. Finally, three conservation strategies for managing and improving ecosystem services were proposed and discussed
with the aim of achieving coordinate and sustainable development of the socioeconomy, environment, and ecosystems not only
in Shandong Province but also in other provinces of China, as well as in other developing and transitional countries and regions. 相似文献
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40.
Katja Hogendoorn Ni Watiniasih Michael P. Schwarz 《Behavioral ecology and sociobiology》2001,50(3):275-282
The possibility of extending brood care via the overlapping presence of relatively short lived adults could generate advantages that may have been among the selective forces at the origin of eusociality. In this paper we provide evidence for extended brood care through sib-rearing in the arid-zone allodapine bee, Exoneurella eremophila. Solitary females of the overwintered generation generally die before all their offspring have become independent. In a relatively high proportion of nests, a newly eclosed female invests in her siblings while producing her own offspring in the maternal nest. The sex ratio of the first offspring produced by the overwintered female is highly female biased, but the overall sex ratio of the brood is unbiased. This finding supports the prediction of Bull's 'insurance by protogyny' model of a female bias in the first-produced offspring as a strategy by the mother to ensure extended brood care. 相似文献