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921.
此文在放射性固体废物压缩封装机(详见本刊1991年第12期),的基础上,阐述了其运行过程中的污染设施和防污效果。调查表明,放射性固废压缩封装工艺必须辅以适当的辐射防护措施,宜采取供风和排风相结合的通负形式,使运行车间维持一定的负压。监测数据表明,采取以上措施后,车间和周围环境中的气载放射性核素浓度仅为国标(GB4792-8)DAC规定值的1/30,工作场所表面污染水平均在GB8703-88给出的控 相似文献
922.
川西草原十字花科油料植物资源的研究和利用 总被引:12,自引:0,他引:12
首次对四川西部草原的野生十字花科油料植物资源作了比较系统的调查研究,收集植株和种子标本约12属20种。经过种子油分分析和引种观察,筛选出几种有特种用途且适应力较强的植物资源。这些植物资源是蕴藏量大的食用油料播娘蒿(Descurainia sophia)、菥蓂(Thlaspi arvense),高亚油酸的优质食用油料植物高蔊菜(Rorippa elata),高亚麻酸的工业用油料植物涩荠(Malcolmia africana)、独行菜(Lepidiumapetalum)等。可供进一步的开发利用。 相似文献
923.
Structural and photocatalytic properties of TiO2 films fabricated on silicon substrates by MOCVD method 总被引:3,自引:0,他引:3
Silicon(111) and Silicon(100) were employed for fabrication of TiO2 films by metal organic chemical vapor deposition( MOCVD).Titanium(Ⅳ) isopropoxide(Ti[O(C3H7)4]) was used as a precursor. The as-deposited TiO2 films were characterized with FE-SEM, XRD and AFM. The photocatalytic properties were investigated by decomposition of aqueous Orange Ⅱ. And UV-VlS photospectrometer was used for checking the absorption characteristics and photocatalytic degradation activity. The crystalline and structural properties of TiO2 film had crucial influences on the photodegradation efficiency. For MOCVD in-situ deposited films on Si substrates, the photoactivities varied following a shape of “M”: at Iower(350℃ ), middle(500℃ ) and higher(800℃ ) temperature of deposition, relative lower photodegradation activities were observed. At 400% and 700% of deposition, relative higher efficiencies of degradation were obtained, because one predominant crystallite orientation could be obtained as deposition at the temperature of two levels, especially a single anatase crystalline TiO2 film could be obtained at 700℃. 相似文献
924.
连云港港口渔船防污工作的调查与思考 总被引:2,自引:0,他引:2
通过对连云港港口渔船防污工作的现场调查,分析了存在的问题,对渔船的污染危害进行了评估,并提出了对策。 相似文献
925.
通过分析我国污泥处理处置的现状及国内外污泥处理处置发展动态,指出目前污泥处理过程中在污泥处理责任主体、污泥监管系统和相关标准上存在的若干问题,以及就目前各种污泥的处置方案,引出污泥处理处置的认识误区,从而对污泥处置方法进行分析说明,找出一条经济可行、管理方便的处理对策,并对污泥的最终处置方式提出合理的建议。 相似文献
926.
对以天然气、食盐为原料生产基础化工产品的综合性化工企业的职工调查显示,恶性肿瘤已成为该企业职工死亡的主要原因之一,总死亡率为1.44‰,与当地对照有显著性,尤以肺癌、肝癌、食道癌为主.动态观察显示,职工恶性肿瘤死亡率从1971~的0.41‰上升为1996~的1.93‰,总体呈现逐年上升的趋势.1991~以来的男、女职工死亡性比率为1.90∶1,两者差异非常显著,目前3位死因都有统计学意义.这说明恶性肿瘤对该企业职工,特别是男性职工的生命健康威胁越来越大,应成为今后卫生工作的重点之一. 相似文献
927.
磁化技术在含酚废水处理中的应用 总被引:5,自引:0,他引:5
将磁化技术与含酚废水的处理过程相结合。实验结果表明,应用磁化技术能够明显地改善絮凝氧化法处理含酚废水的效果,提高去酚率。 相似文献
928.
A lek is a clump of male territories that females visit only for mating; it is quite a rare mating system among mammals. As we wanted to investigate the role of past male mating success on their fidelity to lek territories, we displaced fallow deer females by a lek (Lek A), i.e. we removed the resources for rutting males. They moved to a new area followed by some of the territorial males (mobile males) where they established a new lek (Lek B). Other males (faithful males) stayed on Lek A. The former had lower mating success and dominance ranking in the early, undisturbed part of the rut. After disturbance, the MS of faithful males was much reduced, while that of mobile males was higher on Lek B than it had been on Lek A. We then disturbed Lek B. Females returned to Lek A, and the mating success of faithful males reverted to its original level. Past mating success was the main factor predicting whether a male was faithful or mobile. We illustrated for the first time the importance of past experience in promoting lek fidelity; this experiment gives an insight into the mechanisms leading to the traditional use of leks. 相似文献
929.
Jinbo Xiong Chaohua Wang Zhiyuan Yao Pingping Zhan Xianghua Yi Jiong Chen 《环境科学学报(英文版)》2023,35(2):429-439
Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes. Existing studies have primarily focused on bacterial responses to antibiotic pollution, but they ignored the microeukaryotic counterpart, though microeukaryotes are functionally important (e.g., predators and saprophytes) in microbial ecology. Herein, we explored how the assembly of sediment microeukaryotes was affected by increasing antibiotic pollution at the inlet (control) and across the outlet sites along a shrimp wastewater discharge channel. The structures of sediment microeukaryotic community were substantially altered by the increasing nutrient and antibiotic pollutions, which were primarily controlled by the direct effects of phosphate and ammonium (−0.645 and 0.507, respectively). In addition, tetracyclines exerted a large effect (0.209), including direct effect (0.326) and indirect effect (−0.117), on the microeukaryotic assembly. On the contrary, the fungal subcommunity was relatively resistant to antibiotic pollution. Segmented analysis depicted nonlinear responses of microeukaryotic genera to the antibiotic pollution gradient, as supported by the significant tipping points. We screened 30 antibiotic concentration-discriminatory taxa of microeukaryotes, which can quantitatively and accurately predict (98.7% accuracy) the in-situ antibiotic concentration. Sediment microeukaryotic (except fungal) community is sensitive to antibiotic pollution, and the identified bioindicators could be used for antibiotic pollution diagnosis. 相似文献
930.
Although the role of macroinvertebrates in the nutrient cycling of the Indo-Pacific mangrove ecosystems is now a paradigm of ecological research, most of the research and scientific assumptions deal with decapod crustaceans alone. However, decapods are not the only representatives of mangrove macrobenthos and in certain mangals they are surely outnumbered by gastropods, especially by potamidids of the genus Terebralia. This paper aims at bridging the gap in the knowledge of the ecological role of the largest and most abundant potamidid species of the Indo-Pacific mangals, the semiterrestrial T. palustris. In particular we studied size structure and distribution in relation to micro-environmental factors and feeding ecology, both in terms of diet composition and grazing rate, of two populations of this gastropod colonising a Kenyan mangrove creek. In contrast to what has been described by various authors concerning other mangals, in our study site juveniles and adults of T. palustris were present throughout the whole forest, from the landward belt to the seaward fringe, locally reaching very high densities at various levels. Both life stages showed a preference for patches characterised by soil with high organic content; thus the habitat of juveniles largely overlapped with that of the adults, although they are known to occupy different ecological niches. Indeed, gut-content analysis confirmed that juveniles are detritivorous and adults are mainly leaf-litter consumers. In situ experiments on the grazing activity of the adult snails showed that, in contrast to the litter-consuming crabs, they feed in every light and tidal condition, for an hourly consumption rate of ~0.65 g per snail. Considering an average density of about 10.5 adults m–2, it is estimated that a total of 10.5 leaves m–2 are removed by adult snails in each tidal cycle (i.e. about every 6 h). T. palustris is the only leaf consumer capable of searching for food under water during high tide and is responsible for the removal of a great quantity of mangrove litter. The results of the present study strongly suggest that T. palustris plays a major role in the food web, mangrove litter degradation and nutrient cycling of the Kenyan mangal.Communicated by R. Cattaneo-Vietti, Genova 相似文献