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141.
Characterizing the optimal operation of photocatalytic degradation of BDE-209 by nano-sized TiO2 总被引:1,自引:0,他引:1
Ka Lai Chow Yu Bon Man Jin Shu Zheng Yan Liang Nora Fung Yee Tam Ming Hung Wong 《环境科学学报(英文版)》2012,24(9):1670-1678
Brominated flame retardants have been widely used in industry. There is a rapid growing public concern for their availabilities in the environment. Advanced oxidation process (AOP) is a promising and efficient technology which may be used to remove emerging chemicals such as brominated flame retardants. This project aims at investigating optimal operational conditions for the removal of BDE-209 using nano-scaled titanium(IV) oxide. The residual PBDE congeners after photocatalytical degradation of BDE-209 by TiO2 were analysed by gas chromatography-mass spectrometry (GC-MS). It was found that the degradability of BDE-209 by TiO2 was attributed to its photocatalytic activity but not the small size of the particles. The half-life of removing BDE-209 by TiO2 was 3.05 days under visible light. Tetra- and penta-BDEs were the major degraded products of BDE-209. Optimum conditions for photocatalytical degradation of BDE-209 was found to be at pH 12 (93% ± 1%), 5, 10, 20 mg/L (93.0% ± 1.70%, 91.6% ± 3.21%, 91.9% ± 0.952%, respectively), respectively of humic acid and in the form of anatase/rutile TiO2 (82% ± 3%). Hence, the efficiency of removing BDE-209 can be maximized while being cost effective at the said operating conditions. 相似文献
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Nielsen Jytte Seested Chilton Susan Metcalf Hugh 《Environmental Economics and Policy Studies》2019,21(1):61-86
Environmental Economics and Policy Studies - The risk–risk trade-off method is a technique used to elicit the relative trade-off between changes in morbidity and mortality risks in stated... 相似文献
144.
David A. Wiedenfeld Allison C. Alberts Ariadne Angulo Elizabeth L. Bennett Onnie Byers Topiltzin Contreras-MacBeath Gláucia Drummond Gustavo A. B. da Fonseca Claude Gascon Ian Harrison Nicolas Heard Axel Hochkirch William Konstant Penny F. Langhammer Olivier Langrand Frederic Launay Daniel J. Lebbin Susan Lieberman Barney Long Zhi Lu Michael Maunder Russell A. Mittermeier Sanjay Molur Razan Khalifa al Mubarak Michael J. Parr Jonah Ratsimbazafy Anders G. J. Rhodin Anthony B. Rylands Jim Sanderson Wes Sechrest Pritpal Soorae Jatna Supriatna Amy Upgren Jean-Christophe Vié Li Zhang 《Conservation biology》2021,35(5):1388-1395
Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss. 相似文献
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Dr Theresa M. Marteau Rachel Cook Jane Kidd Susan Michie Marie Johnston Joan Slack Robert W. Shaw 《黑龙江环境通报》1992,12(3):205-214
The purpose of the study was to describe the impact of false-positive results from initial maternal serum alpha-fetoprotein (MS-AFP) screening. The analyses compared two groups of women, those receiving a negative result (n = 346) and those receiving an initial positive result (n = 26), over four time points—prior to testing, immediately after testing, later in pregnancy, and in the post-partum period. Receiving an abnormal result was associated with high levels of anxiety which were reflected in increased worry about the baby's health and a more negative attitude towards the pregnancy and the baby. Women who had an initial abnormal result were offered a variety of further tests. Those women who went on to have amniocentesis were less worried about their baby's health in the third trimester and also less anxious post-partum than those who did not have amniocentesis. In view of the increasing number of screening tests available, it is necessary to establish whether and how these levels of distress can best be reduced. 相似文献
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Karen Filkins M.D. F.A.C.O.G. Joseph Russo Thomas Brown Susan Schmerler Bernard Searle 《黑龙江环境通报》1984,4(3):223-226
Thirty-one genetic amniocenteses involving multiple gestations were performed in the genetics unit between 1976 and 1982. Three sets of triplets were included. Precise locations of the sacs were determined using real-time ultrasonography and successful sampling of all sacs was accomplished. Spontaneous abortions occurred in two normal twins and one normal triplet gestation. Two therapeutic abortions were performed for fetal abnormalities. Two cases of discordance for trisomy 21 (one twin and one triplet) were allowed to continue; the twin case terminated at 25 weeks' gestation with neonatal deaths and the triplets are alive and well. 相似文献
150.
Introduction of combined screening with maternal serum alpha-fetoprotein and human chorionic gonadotropin (MShCG) assays for fetal chromosome defects requires establishment of the normal range for twins. This report documents that the normal range for MShCG between 15 and 19 weeks in twin gestations was 1.84–2.41 multiples of the singleton median. Of the 192 twin pregnancies studied, 31.7 and 47.9 per cent had MShCG values ≥2.5 and ≥ 2.0 multiples of the singleton median, respectively. 相似文献