沈阳北部污水处理厂优化运行管理实践

满负荷运行、达标排放是运行管理的使命和责任,摸索运行规律是优化运行管理的基础和前提,变废为宝资源利用是动力和方向。     

废弃印刷电路板资源化回收利用技术探讨

废弃印刷电路板成分复杂,在含有大量可回收金属的同时,还含有多种有害物质,其资源化回收和处置技术受到国内外广泛的关注。对目前主要的废弃印刷电路板回收利用技术应用状况和实践进展进行了分析。机械法．化学冶金法是目前广泛应用的以回收废弃印刷电路板中的金属为主要目的的回收技术。应用热解技术处理废弃印刷电路板,不仅可以有效回收废弃印刷电路板中的金属物质,还可以使废弃印刷电路板中的非金属物质得到资源化利用,具有很好的发展前景。     

淮南矿业集团谢桥煤矿矿井水资源化利用

随着淮南矿业集团谢桥煤矿的发展,矿区生产和生活用水量日趋紧张,解决缺水问题的有效途径是合理开发利用矿井水资源。在此论述了煤矿矿井水资源化的必要性,给出了矿井水处理工艺流程、主要建（构）筑物、主要设备等,说明了开发利用矿井水资源具有良好的社会、环境和经济效益。     

浅谈城市固体废物处理

由于城市化速度加快和城市固体废物产量的增加,城市固体废物的处理已成为环境领域研究的热点。在此从城市固体废物的分类入手,分析了城市固体废物的危害,并对目前城市固体废物处理技术进行了对比分析,提出了加快固体废物减量化、资源化和无害化的建议。     

Influence of atmospheric stability on the mass concentration and chemical composition of atmospheric particles: a case study in Rome, Italy

PM(10) concentration and chemical composition (ions and carbon compounds) at three sampling stations in Rome and in its surroundings was determined daily during a one-month field study, carried out during December 2003. PM concentration at the traffic station was considerably higher than at the urban background and semi-rural stations; elemental carbon was detected as one of the chemical components responsible for this increase. The difference in the concentration of sulphate and ammonium was negligible, as it was expected for secondary pollutants. A negative artefact in the determination of ammonium nitrate by means of heated automatic monitors was highlighted. The dilution properties of the lower atmosphere were traced by means of a natural radioactivity monitor. This parameter has been found to play an essential role in pollution buildup. A considerable increase in PM concentration was observed to coincide with periods of atmospheric stability. The main difference in PM composition between periods of high concentration and periods of "clean" air was found to be in the increase of ammonium nitrate concentration.     

Fractionating dead reckoning: role of the compass,odometer, logbook,and home base establishment in spatial orientation

Rats use multiple sources of information to maintain spatial orientation. Although previous work has focused on rats’ use of environmental cues, a growing number of studies have demonstrated that rats also use self-movement cues to organize navigation. This review examines the extent that kinematic analysis of naturally occurring behavior has provided insight into processes that mediate dead-reckoning-based navigation. This work supports a role for separate systems in processing self-movement cues that converge on the hippocampus. The compass system is involved in deriving directional information from self-movement cues; whereas, the odometer system is involved in deriving distance information from self-movement cues. The hippocampus functions similar to a logbook in that outward path unique information from the compass and odometer is used to derive the direction and distance of a path to the point at which movement was initiated. Finally, home base establishment may function to reset this system after each excursion and anchor environmental cues to self-movement cues. The combination of natural behaviors and kinematic analysis has proven to be a robust paradigm to investigate the neural basis of spatial orientation.     

Spatial and temporal variation of below-ground N transfer from a leguminous tree to an associated grass in an agroforestry system

Nitrogen (N) transfer from leguminous trees can be a major N source for the associated crop in low-input agroforestry systems. The aim of this study was to identify the main climatic and soil factors controlling N transfer from the leguminous tree Gliricidia sepium (Jacq.) Walp to the associated grass Dichanthium aristatum (Poir.) C.E. Hubb, in a 16-year-old tropical agroforestry system. Nitrogen transfer was estimated using the natural ¹⁵N abundance method. Before tree pruning, total N transfer represented 57% of the N uptake of the grass, including 31% coming from N₂ fixation. The spatial variation induced by the tree was well described by soil organic N content (ON). In this system, ON is an index of soil available N as well as of tree root density. Rainfall (R) and evapotranspiration (ETP) were the main climatic factors controlling N transfer. Multiple regression analysis indicated that R, ETP and ON explained 79% of the temporal and spatial variation of N transfer. Transferred N cannot be estimated after pruning because of the change in the isotopic signature of the soil N source. This was related to N release from root turnover. The results suggest that grass showed a preferential uptake of N coming from the tree, which could be due to a lower energy cost compared to obtaining absorbed N from the clayey soil used in this work.     

齐齐哈尔市自然保护区发展现状与对策研究

自然保护区是维护生态安全,促进生态文明,实现社会经济可持续发展的重要保障。从齐齐哈尔市自然保护区发展现状及其作用入手,着重分析了在自然保护区建设管理中存在的问题,并在此基础上,提出了管理的对策。     

扎龙自然保护区鸻形目水禽的现状调查

本文在扎龙自然保护区内对鸻形目水鸟的种类、数量及生境进行了调查。结果表明,扎龙保护区现有鸻形目迁徙水鸟28种,其中近年来的新纪录种有3种,种群数量超过1000只的4种;鸻形目繁殖水鸟12种,其中数量超过1000只的优势种3种;实施生态补水以来,以优势种为代表的鸻形目水鸟的繁殖种群数量显著增加。     

Severity of emergency natural gas distribution pipeline incidents: Application of an integrated spatio-temporal approach fused with text mining

The transportation of natural gas often relies on pipelines which require constant monitoring and regular maintenance to prevent spills or leaks. Pipeline incidents could pose a huge adverse impact on people, the environment, and society. Numerous efforts have been invested to identify contributing factors to pipeline incidents so that countermeasures could be developed to proactively prevent some incidents and reduce incident severities or impacts. However, the countermeasures may need to vary for different incidents due to the potential heterogeneity between incidents, and such heterogeneity is likely related to the geology, weather, and built environment which vary across space and time domain. The objective of this study is to revisit the correlates of pipeline incidents, focusing on the spatial and temporal patterns of the correlations between natural gas pipeline incident severity and contributing factors. This study leveraged an integrated spatio-temporal modeling approach, namely the Geographically and Temporally Weighted Ordered Logistic Regression (GTWOLR) to model the natural gas pipeline incident report data (2010–2019) from the U.S. Pipeline and Hazardous Material Safety Administration. Text mining was performed to extract additional information from the narratives in reports. Results show several factors have significant spatiotemporally varying correlations with the pipeline incident severity, and these factors include excavation damage, gas explosion, iron pipes, longer incident response time, and longer pipe lifetime. Findings from this study are valuable for pipeline operators, end-users, responders to jointly develop localized strategies to maintain the natural gas distribution system. More implications are discussed in the paper.