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991.
本文研究了皮革铬鞣废水中铬的定性特征曲线。利用吸光度加合定律对大量实测数据进行统计处理。建立测定铬的实验室校准直线方程,相关系数γ=0.9960.以此作为测定铬鞣废水及回收铬渣中铬量的实验室回归直线方程。并对本法的可靠性进行研究,结果令人满意。本法不仅大大简化了铬量测定的步骤.而且在提高分析效率的同时获得同等的检测结果。 相似文献
992.
TAKU MATSUSHITA YOSHIHIKO MATSUI YUSUKE MATSUI TAKANOBU INOUE 《Journal of environmental science and health. Part. B》2013,48(6):851-861
The mutagenicity of chlornitrofen (CNP)-containing solutions has been reported to increase during anaerobic biodegradation. In the present study, the fate of this increased mutagenicity under subsequent aerobic and anaerobic incubation conditions was investigated using two Salmonella tester strains, YG1024 (a frameshift-detecting strain) and YG1029 (a base-pair-substitution-detecting strain). Mutagenicity for both YG1024 and YG1029 strains increased during nine-day anaerobic biodegradation. During subsequent anaerobic incubation, the increased mutagenicity decreased gradually for YG1029 but did not change significantly for YG1024. By contrast, the increased mutagenicity decreased rapidly after the conversion to aerobic incubation for both YG1024 and YG1029 strains. The rapid decrease in mutagenicity during aerobic incubation was due to decreases, not only in an identified mutagenic metabolite (CNP-amino) but also in unidentified mutagenic metabolites. 相似文献
993.
Olimpia Pepe Valeria Ventorino Giuseppe Blaiotta 《Waste management (New York, N.Y.)》2013,33(7):1616-1625
Although several reports are available concerning the composition and dynamics of the microflora during the composting of municipal solid wastes, little is known about the microbial diversity during the composting of agro-industrial refuse. For this reason, the first parts of this study included the quantification of microbial generic groups and of the main functional groups of C and N cycle during composting of agro-industrial refuse. After a generalized decrease observed during the initial phases, a new bacterial growth was observed in the final phase of the process. Ammonifiers and (N2)-fixing aerobic groups predominated outside of the piles whereas, nitrate-reducing group increased inside the piles during the first 23 days of composting. Ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), showed an opposite trend of growth since ammonia oxidation decreased with the increase of the nitrite oxidation activity. Pectinolytics, amylolytics and aerobic cellulolytic were present in greater quantities and showed an upward trend in both the internal and external part of the heaps.Several free-living (N2)-fixing bacteria were molecularly identify as belonging especially to uncommon genera of nitrogen-fixing bacteria as Stenotrophomonas, Xanthomonas, Pseudomonas, Klebsiella, Alcaligenes, Achromobacter and Caulobacter. They were investigated for their ability to fix atmospheric nitrogen to employ as improvers of quality of compost. Some strains of Azotobacter chrococcum and Azotobacter salinestris were also tested. When different diazotrophic bacterial species were added in compost, the increase of total N ranged from 16% to 27% depending on the selected microbial strain being used. Such microorganisms may be used alone or in mixtures to provide an allocation of plant growth promoting rhizobacteria in soil. 相似文献
994.
Water samples were collected in the Northeast Atlantic Ocean (33-37° N and 11-16° W) in May 1983, and vertical profiles of chemical and physical parameters allowed us to identify the different water masses. A significant difference in salinity and its maximum can be found at different places and depths, as a consequence of the spreading of the Mediterranean Water (MW) from the Strait of Gibraltar. The apparent oxygen utilization shows a correlation with nutrients in North Atlantic Central Water. The relative percentages of water masses were assessed in order to examine the depth of maximum influence of MW as a function of latitude and to apply this knowledge to the black scabbard fish long-line strategy. The long-line fishing depth location was adapted to the specific MW distribution of the different banks with improvements in the mean catch efficiency. The thickness of the MW prevalence layer has a pronounced decrease to the south. MW influence clearly sinks and decrease to south-west. The highest percentage of the MW was found in the Gorringe Bank area and the lowest in the Madeira area. 相似文献
995.
为提高煤矿井下人员身份识别率,在局部保持投影(LPP)算法的基础上,提出监督局部映射(SLP)算法。该方法充分利用数据的局部和非局部信息及类别信息,对数据进行维数约简,使特征空间同类数据间的距离更小,不同类数据间的距离更大。该方法能够克服煤矿井下艰苦、空间受限环境中人脸、虹膜和指纹识别率不高的问题。在真实步态数据库上的实验结果表明,基于步态的煤矿井下人员身份鉴别是可行的。 相似文献
996.
民用压缩气体和液化气体一旦发生爆炸,会造成很大的破坏力。根据压缩气体和液化气体的特性,通过计算,由爆炸中心到能保证人身安全和建筑(构筑)物和设备免遭破坏的最小距离。 相似文献
997.
Early research showed that citizens’ environmental concern in the United States was linked to three individual-level factors: socio-demographic variables, political orientations, and personal beliefs or worldviews about human-nature relations. Given many changes in the American society over the last several decades, one important, yet unanswered question is whether these factors still drive public environmental concern in the United States today, and if so, to what extent. This study, drawing from extant theoretical and empirical studies, aims to reinvestigate the determinants of citizens’ environmental concern by employing three national public surveys conducted in 2004, 2007, and 2013. Our data analyses confirm and expand the findings of previous research on the significance and importance of political ideology, fundamental beliefs about human-nature relations, and certain socioeconomic factors such as gender and race in explaining citizens’ environmental concern. More specifically, political liberals, people with higher New Ecological Paradigm values, females, and Non-Whites tend to be more concerned about environmental problems than their counterparts are. Our data analyses also reveal some interesting findings when compared to many previous studies: first, our data indicate a positive relationship between age and environmental concern, suggesting that older people in the United States are more concerned about the environment than younger adults; second, unlike most past research showing a positive Education-Environmental Concern relationship, our study suggests that education level seems to have little effect in explaining citizens’ environmental concern measured in this study. Key implications for environmental policymaking and recommendations for future research are discussed in the conclusion. 相似文献
998.
Voluntary markets transacted over $66 million USD of forest carbon offsets in 2016, according to Forest Trends, and over 99% of those offset projects were audited to a standard, primarily the Verified Carbon Standard (VCS). We provide a table characterizing all 70 validated and verified forest carbon projects employing the VCS version 3.0 currently-in-use (December 2011–July 2017). We also examine two separate aspects of the audit process––impact and thoroughness––to assess the effectiveness of the costly audit process, which can consume up to one-third of offset revenue. Audit impact we measure in terms of reduction in the number of offsets from ex ante estimated to ex post approved. Audit thoroughness we measure both directly in terms of the number of auditor hours worked per project and also indirectly in terms of the total number of Corrective Action Requests (CARs)/Non-Conformity Reports (NCRs) auditors prescribe. In terms of impact, we find that Afforestation/Reforestation/Restoration (A/R/R) and Improved Forest Management (IFM) projects, though only constituting 5% of total verified offsets, demonstrate significant (p < = 0.05) reductions from ex ante estimated to ex post approved offsets, likely because auditors can easily scrutinize carbon stocks/emission factors for the commercial tree species involved in these project types. In terms of thoroughness, we find that higher ex ante estimates correlate with more total auditor hours worked and total CARs/NCRs prescribed for three of four project activity types, likely because auditors perceive larger ex ante projects as higher risk. We conclude with recommendations for the VCS to empower auditors to scrutinize carbon stocks/emissions factors from avoided deforestation projects, and also to continue to flag high ex ante projects as higher risk. 相似文献
999.
武钢三烧区域改建了二台大连三洋蒸汽型双效溴化锂吸收式制冷机。叙述了该改建项目的主机选型、参数选定、设计特点等。 相似文献
1000.
《Disasters》1999,23(3):271-276
Books reviewed:
Tim Dyson, Population and Food: Global Trends and Future Prospects
R. S. J. Sparks, M. I. Bursik, S. N. Carey, J. S. Gilbert, L. S. Glaze, H. Sigurdsson and A. W. Woods, Volcanic Plumes
Jasper Becker, Hungry Ghosts: Mao's Secret Famine
Dali L. Yang, Calamity and Reform in China: State, Rural Society and Institutional Change Since the Great Leap Forward 相似文献
Tim Dyson, Population and Food: Global Trends and Future Prospects
R. S. J. Sparks, M. I. Bursik, S. N. Carey, J. S. Gilbert, L. S. Glaze, H. Sigurdsson and A. W. Woods, Volcanic Plumes
Jasper Becker, Hungry Ghosts: Mao's Secret Famine
Dali L. Yang, Calamity and Reform in China: State, Rural Society and Institutional Change Since the Great Leap Forward 相似文献