小船的防油污措施

行驶于中国江河湖海的成千上万艘小于４００ 总吨的船舶，是造成水域环境油污染的主要原因之一。国际防污公约对这类船舶的防油污措施并无详细规定。文中介绍一种相应的举措，可供各地主管部门、船东、船舶修造厂、船员等参考。     

中国西南地区近千年湖泊水位变化

重建湖泊水位历史、掌握其演变规律和机制,对水资源管理、生态环境保护、旱涝灾害防治以及认识区域水文气候变化机制皆有重要意义.中国西南地区拥有大量湖泊,其水位变化及驱动机制广受关注.本文通过汇总历史文献记录并将其与邻近地区的其他湖泊水位重建进行比较,总结了过去一千年中国西南地区湖泊水位的变化.结果显示中国西南地区近千年的湖...     

Mercury deposition/accumulation rates in the vicinity of a lead smelter as recorded by a peat deposit

Mercury (Hg) concentration profiles and historical accumulation rates were determined in three ²¹⁰Pb-dated cores from a peat deposit in the vicinity of a lead (Pb) smelter at Příbram, Czech Republic. The Hg concentrations in peat samples ranged from 66 to 701 μg kg⁻¹. Cumulative Hg inventories from each core (for the past 150 yr) varied by a factor of 1.4 (13.6–18.5 mg Hg m⁻²), indicating variations of net Hg accumulation rate within the peat deposit. Historical changes in vegetation cover (leading to variable interception by trees) are probably responsible for this variation in space and time. The uncorrected Hg accumulation rates peaked between the 1960s and 1980s (up to 226 μg m⁻² yr⁻¹). Recent findings show that Hg records from peat tend to overestimate historical levels of Hg deposition. Therefore we used the mass loss compensation factor (MLCF) to normalize Hg accumulation rates. These corrected Hg accumulation rates were significantly lower (maximum 129 μg m⁻² yr⁻¹) and better corresponded to changes in historical smelter emissions, which were highest in the 1960s. The agreement between the corrected Hg accumulation rates in the uppermost peat sections (2–38 μg m⁻² yr⁻¹) and biomonitoring of atmospheric deposition by mosses in several recent years (4.7–34.4 μg m⁻² yr⁻¹) shows the usefulness of MLCF application on Hg accumulation in peat archives. However, the MLCF correction was unsuitable for Pb. The recent Pb deposition rates obtained by an independent biomonitoring study using mosses (0.5–127 mg m⁻² yr⁻¹) were better correlated with net Pb accumulation rates recorded in peat (7–145 mg m⁻² yr⁻¹) than with corrected rates obtained by the MLCF approach (1–28 mg m⁻² yr⁻¹).     

On Uncertain Sightings and Inference about Extinction

The extinction of many species can only be inferred from the record of sightings of individuals. Solow et al. (2012, Uncertain sightings and the extinction of the Ivory‐billed Woodpecker. Conservation Biology 26: 180–184) describe a Bayesian approach to such inference and apply it to a sighting record of the Ivory‐billed Woodpecker (Campephilus principalis). A feature of this sighting record is that all uncertain sightings occurred after the most recent certain sighting. However, this appears to be an artifact. We extended this earlier work in 2 ways. First, we allowed for overlap in time between certain and uncertain sightings. Second, we considered 2 plausible statistical models of a sighting record. In one of these models, certain and uncertain sightings that are valid arise from the same process whereas in the other they arise from independent processes. We applied both models to the case of the Ivory‐billed Woodpecker. The result from the first model did not favor extinction, whereas the result for the second model did. This underscores the importance, in applying tests for extinction, of understanding what could be called the natural history of the sighting record. Sobre Avistamientos Inciertos e Inferencia de la Extinción     

项目核准备案与环评审批衔接存在问题及对策

投资体制改革后项目核准备案与环评审批衔接过程中存在诸多问题,拟从政策、法律、部门配合等层面提出对策和建议。     

新疆博斯腾湖重金属污染的沉积记录

通过测定柱芯沉积物中重金属含量,分析了新疆博斯腾湖重金属污染水平、来源及其变化趋势。结果表明,博斯腾湖西岸Pb、Zn和Cu的地质积累指数均小于0.5,污染较轻,主要来源于自然源。西南小湖区重金属Zn、Cu、Ni、Co污染较轻,主要来源于岩石风化等地球化学过程;重金属Pb和Cd污染中等,主要来源于农业活动中磷酸盐肥料的使用,1960 s以来增加显著,近年来呈明显的上升趋势。     

围岩位移自动监测记录系统

以往围岩位移监测的位移数据是先埋设好位移监测的设备后由工作人员定时采集。这种方式不能准确记录岩体发生变形的时间,数据量也较少,不利于对危险情况及时发现处理以及数据的后期研究分析。自动化监测系统采用短时间间隔的数据采集可以很好的克服以上的缺点。系统采用USB存储方式,将监测数据以文本文件的格式直接存储到U盘上,可以更方便的应用计算机处理数据。     

Using data mining technology to explore causes of inaccurate reliability data and suggestions for maintenance management

Reliability data reflects equipment safety and provides a reference for setting inspection period, thereby serving as crucial information for the implementation of equipment integrity management policies. The calculation foundation of reliability data is maintenance records of adequate data quality. However, maintenance records of doubtful quality are common. Despite excluding poor quality recodes and using only the remaining maintenance recodes to calculate the reliability data, the calculated results generally lack a sufficient degree of confidence. This study applied data mining technology, including quality metrics, the association rule, and clustering, to explore the cause of low-quality maintenance data. The results revealed that the low data quality of maintenance records was due to ineffective maintenance policies, the low integrity of key system columns, nonadherence to the policy, and misunderstanding of column definitions. The proposed method successfully identified the causes of low-quality maintenance records. By incorporating the method into the function module of a CMMS, operators can equip the system with self-diagnosis, self-supervision, and continuous optimization functions.