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91.
综述了国内外丁二烯过氧化物研究进展,主要包括丁二烯过氧化物的危害性、成因、危险评价和热稳定性,并对今后的研究方向进行了展望。  相似文献   
92.
自动化技术在能源、电力、机械、环境等行业的应用越来越广泛,也促使了自动化水平的不断提高。由于Synall2000强大的网络化功能,为将来系统在子网级和企业级实施基于Synall2000网络化数据监控系统打下了坚实、可靠的基础。在全面实施单个站点自动化监控的基础上,可方便地实现子网级的网络化数据自动采集与监控系统。  相似文献   
93.
对一起油罐爆炸火灾事故进行了调查,对回流油速度进行了测算,从静电的产生和放电、爆炸性气体混合物的形成进行了分析和研究,指出了火灾原因,提出了应吸取的教训。  相似文献   
94.
针对现有城市生活垃圾处理方式的不足,结合垃圾生物处理特点,设计了集混合菌群降解、生物过滤除臭、污水回用及植被绿化于一体的立体处理体系。结果表明,该系统在城市生活垃圾的“三化”处理中具有显著的潜势:既使生活垃圾在食物链外形成安全的闭路循环,防止有害物质向人居环境入渗;同时,处理设施的立体化、终产物的生物转化以及即刻的市场效应,有效地增强了系统的消纳能力,缓解了传统处理方式对城市空间的压力。该系统对我国中小城市生活垃圾的综合利用具有积极的参考价值。  相似文献   
95.
为了寻找甲基汞神经毒性检测和评价效应指标以及探讨甲基汞神经毒性分子机制,对大鼠进行氯化甲基汞(MMC)急性暴露(对照组为0.9%生理盐水、暴露组浓度为0.05mg/kg),20min后对大鼠进行生理生化指标和即早基因的检测,大鼠大脑中枢神经系统的神经递质一氧化氮合酶活力采用一氧化氮合酶(NOS)测定试剂盒检测;自由基脂质过氧化产物丙二醛含量采用硫代巴比妥酸(TBA)比色法检测;即刻早期基因c-fos表达的变化采用免疫组化方法检测。结果表明,在暴露氯化甲基汞(MMC)20min后,大鼠大脑中枢神经系统的一氧化氮合酶活力、自由基脂质过氧化产物丙二醛含量以及即刻早期基因(IEG)c-fos蛋白阳性表达数量都有提高。但其中一氧化氮合酶活力及自由基脂质过氧化产物丙二醛含量同对照组相比没有显著性差异;而即刻早期基因c-fos的阳性表达同对照组相比有极显著性差异(P<0.01)。据此可以推测,即刻早期基因能作为甲基汞神经毒性检测和评价效应指标,一氧化氮合酶、丙二醛和即刻早期基因在甲基汞神经毒性过程中具有重要作用。  相似文献   
96.
Reclaiming abandoned and unmaintained roads, built originally for forestry and mineral extraction, is an important part of ecological restoration, because the roads running through natural habitats cause fragmentation. The roads can be reclaimed in a passive way by blocking access to the road, but successful seedling recruitment may require additional management due to the physical constraints present at the road. We established a full factorial study to compare the effects of three road reclaiming measures, namely ripping, creation of safe sites by adding mulch and pine seed addition, on soil processes, recovery of understorey vegetation and seedling recruitment in three conservation areas in eastern Finland. We surveyed soil organic matter, frequency and cover of plant functional types, litter and mineral soil, and number of tree seedlings. The soil organic matter was, on average, 1.3-fold in the 50-cm-deep ripping treatment relative to unripped and 20-cm-deep ripping treatments. The germination and survival of deciduous seedlings and grass establishment were promoted by adding mulch. The addition of pine seeds counteracted the seed limitation and enhanced the regeneration of trees. The treatment combination consisting of ripping, adding mulch and pine seed addition enhanced the vegetation succession and tree-seedling recruitment most: the cover of grasses, herbs and ericaceous dwarf shrubs was 1.3–7.6-fold and the number of coniferous tree seedlings was 3.4–7.1-fold relative to the other treatment combinations. Differences between short-term (1–3 years) and longer-term (6 years) results indicate the need for a sufficient observation period in road reclamation studies.  相似文献   
97.
The Taranto basin is a shallow water marine system in the South of Italy characterized by the presence of a lagoon environment together with a semi-enclosed bay connected to the Ionian Sea. This marine system experienced over the last few decades strong biochemical pollution and environmental degradation, and it is considered a hotspot study site for economic, ecological and scientific reasons. The aim of this study was to examine, on an annual temporal scale and with high spatial resolution, the main hydrodynamical processes and transport scales of the system by means of a 3D finite element numerical model application, adopting the most realistic forcing available. The model allowed us to assess the role played by baroclinic terms in the basin circulation, describing its estuarine nature. In particular, the main features of water circulation, salinity and temperature distribution, water renewal time and bottom stress were investigated. Our results allowed us to equate this system dynamic to that of a weakly stratified estuary, identifying the main driving sources of this mechanism. The vertical stratification over the whole year was proved to be stable, leading to a dual circulation flowing out on the surface, mainly through Porta Napoli channel, and inflowing on the bottom mainly through Navigabile channel. This process was responsible also for the renewal time faster on the bottom of the Mar Piccolo basin than the surface. Due to the great importance of the Taranto basin for what concerns sediment pollution, also the effect of currents in terms of bottom stress was investigated, leading to the conclusion that only in the inlets area the values of bottom stress can be high enough to cause erosion.  相似文献   
98.
Mercury is a well-known toxic element, and flue gas streams emitted from coal-fired utilities are one of the largest anthropogenic sources of this element. This study briefly reviews the proposed technologies for reducing mercury emissions from coal combustion, focusing on an emerging process which involves the use of regenerable sorbents and especially those loaded with noble metals. Among the mercury species formed during coal combustion, elemental mercury is the most difficult to remove from the flue gases due to its low reactivity and insolubility in water. The widespread interest in using regenerable sorbents with metals is due to their ability to retain elemental mercury. With this technology, not only can efficiencies of 100 % be reached in the retention of elemental mercury but also a way to avoid the generation of new wastes loaded with mercury. This study considers the main aspects that must be taken into account when developing effective regenerable sorbents for mercury capture, with special attention to sorbents containing noble metals. The characteristics of this process are compared with those of other processes in a more advanced state of development.  相似文献   
99.
Among the mitigation strategies to prevent nitrogen (N) losses from ureic fertilizers, urease inhibitors (UIs) have been demonstrated to promote high N use efficiency by reducing ammonia (NH3) volatilization. In the last few years, some field experiments have also shown its effectiveness in reducing nitrous oxide (N2O) losses from fertilized soils under conditions of low soil moisture. An incubation experiment was carried out with the aim of assessing the main biotic mechanisms behind N2O emissions once that the UIs N-(n-butyl) thiophosphoric triamid (NBPT) and phenil phosphorodiamidate (PPDA) were applied with Urea (U) under different soil moisture conditions (40, 60 and 80 % water-filled pore space, WFPS). In the same study we tried to analyze to what extent soil WFPS regulates the effect of these inhibitors on N2O emissions. The use of PPDA in our study allowed us to compare the effect of NBPT with that of another commercially available urease inhibitor, aiming to see if the results were inhibitor-specific or not. Based on the results from this experiment, a WFPS (i.e. 60 %) was chosen for a second study (i.e. mesocosm experiment) aiming to assess the efficiency of the UIs to indirectly affect N2O emissions through influencing the pool of soil mineral N. The N2O emissions at 40 % WFPS were almost negligible, being significantly lower from all fertilized treatments than that produced at 60 and 80 % WFPS. When compared to U alone, NBPT+U reduced the N2O emissions at 60 % WFPS but had no effect at 80 % WFPS. The application of PPDA significantly increased the emissions with respect to U at 80 % WFPS whereas no significant effect was found at 60 %. At 80 % WFPS, denitrification was the main source of N2O emissions for all treatments. In the mesocosm study, the application of NBPT+U was an effective strategy to reduce N2O emissions (75 % reduction compared to U alone), due to a lower soil ammonium (NH4 +) content induced by the inhibitor. These results suggest that adequate management of the UI NBPT could provide, under certain soil conditions, an opportunity for mitigation of N2O emissions from fertilized soils.  相似文献   
100.
焦化废水是一种典型的含难降解有机污染物的工业废水,除含酚类化合物外,还含有多种芳香烃和杂环类有机物,成分复杂,水量大,对环境污染严重。因此,焦化废水的处理越来越多的受到相关学者及专家的重视。本文首先从焦化废水的来源及特征出发,根据其特殊性,综合阐述了近年来国内外焦化废水的常规处理方法及深度处理方法,为以后焦化废水的处理提供一些思路。  相似文献   
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