世界煤炭资源流动的时空格局及成因分析

基于1990-2016年的统计数据,采用场理论研究世界煤炭资源流动的时空格局变化及其成因,揭示近30年来世界煤炭资源的流动状态及其演变过程。研究结果显示：（1）2016年世界煤炭的输出总量达12.25亿t,比1990年增加了10.13亿t,年均增长6.98%,其中澳大利亚、印尼和俄罗斯等是主要的煤炭输出国,印度、日本、中国和韩国是主要的煤炭输入国;（2）以场理论的位势、流场分布、流动迹线角度分析,世界煤炭资源的流动以北美洲、中南美洲和非洲为源流场,以欧洲及欧亚大陆、中东和亚太为汇流场,在澳大利亚—东亚、印尼—东亚/印度之间形成主要运输航线;（3）资源空间分布、供需匹配程度、空间距离、市场因素和国家政策等是煤炭资源流动的主要动因。研究发现：虽然中国煤炭储量丰富,但是煤炭消费数量庞大,仅可维持72年,必须重视煤炭的进口和储备工作。该研究对于中国科学制定产业政策具有重要价值。     

Bioconcentration of n-dodecane and its highly branched isomer 2,2,4,6,6-pentamethylheptane in fathead minnows

Petroleum products are complex mixtures of hydrocarbons. They are important as constituents of fuels and lubricants, and as key raw materials for the chemicals industry. Since there is a potential for accidental releases to the aquatic environment, bioaccumulation of higher hydrocarbons is of concern. Here, the bioconcentration behaviour of two representative hydrocarbons, the dodecane isomers n-dodecane and 2,2,4,6,6-pentamethylheptane (PMH), was investigated in fathead minnows at concentrations in water below their maximum aqueous solubility. The concentration of n-dodecane in fish did not exceed our method limit of detection of 60 μg/kg. In contrast, PMH could be quantified in fish. No significant increase in the ratio of PMH concentrations in fish to water could be detected indicating that an exposure time of 4–10 days is sufficient to approach steady-state. For n-dodecane the upper limit of the bioconcentration factor (BCF) is estimated by dividing the method limit of detection by the exposure concentration and a value of 240 l/kg is derived. For PMH the bioconcentration factor, estimated as the average fish/water concentration ratio during the steady-state part of the experiment, ranges between 880 and 3500 l/kg. The BCFs of both compounds are small compared to their hydrophobicity. Given that both linear and branched hydrocarbons are known to be biotransformed by fish, it appears that efficient metabolism of the test compounds in fathead minnows prevents bioaccumulation.     

垂直潜流人工湿地堵塞机制：堵塞成因及堵塞物积累规律

为解决垂直潜流人工湿地的堵塞问题,需首先探明人工湿地的堵塞成因和堵塞物在人工湿地中的分布规律.在发生堵塞的垂直潜流人工湿地中,通过研究基质间各物质与雍水面积、基质间空隙率之间的相关关系,发现人工湿地发生堵塞的成因主要是基质层中不可滤物质的积累,并得出以砂子为基质的人工湿地每mL基质间不可滤堵塞物超过18.23 mg时即会出现雍水表观现象;同时研究发现,在本试验条件下,人工湿地布水口周围容易先产生堵塞现象,堵塞层主要分布于距布水管下10～20cm处;基质中不可滤无机物积累的程度比不可滤有机物更明显,且有随着水流方向沿程迁移的趋势;有机物质积累于基质深度基本呈负相关性,基质越深,有机质含量越少,雍水后基质表层有机质含量高于其它各层.     

盘锦“红海滩”退化初探

本文采用海水监测、翅碱蓬野外调查及盆栽试验和室内分析方法,研究了盘锦"红海滩"翅碱蓬群落的退化死亡原因,特别是翅碱蓬退化死亡与土壤盐分的关系。结果表明,翅碱蓬适宜的土壤盐分含量在10g/kg至16g/kg之间,初步认为由于滩涂土壤盐分升高产生的盐害是引起盘锦"红海滩"翅碱蓬群落退化死亡的主要原因。     

Nutritional benefits of filial cannibalism in three-spined sticklebacks (<Emphasis Type="Italic">Gasterosteus aculeatus</Emphasis>)

Although filial cannibalism (eating one’s own offspring) occurs in numerous species, including several teleost fishes, its adaptive value is still not well understood. One often-discussed explanation is that individuals enhance their mass and body condition by consuming part of their eggs. However, evidence for this assumption is scarce thus far. In this study, male three-spined sticklebacks (Gasterosteus aculeatus), a species with paternal care, were allowed to care for a batch of eggs or for an empty nest under food-deprived conditions. All brood-caring males cannibalised at least part of their eggs and thus preserved their initial mass and body condition. Furthermore, mass as well as body condition was significant positively correlated with the number of cannibalised eggs. In contrast, empty-nest males that had no possibility to cannibalise eggs significantly lost mass and body condition. This is, to our knowledge, the first experimentally documented evidence that mass as well as body condition were preserved by filial cannibalism.     

焦炭塔现场操作的危险原因分析和解决措施

根据具体的事故案例,对焦炭塔现场操作过程存在的各种危险进行了原因分析,提出要从完善仪表控制、加强操作工培训、改善操作条件、进行技术动改及不断完善操作规程和各类制度等方面入手,切实做好各类基础工作,才能消除危险,保障安全。     

Assessment of the effect of technical and management characteristics on the frequency of release from piping: An application to a gas storage facility

The assessment of the frequencies of release from piping due to losses of containment is an essential step in the preparing Safety Reports, drawn up as required by the so-called “Seveso” Directive. These are usually calculated starting from the frequencies of random rupture included in international databases and are not plant-specific, furthermore, the quantification of the effect of the safety management system of the facility is not easy. A simple and flexible approach quantifying technical and management characteristics of the plant has been proposed by Milazzo and co-workers in 2010; it is based on the modification of the frequency taken from literature, through the use of the percentages of failure causes actually possible in that plant, and the judgment about their management. The data about the failure causes are taken from the literature and modified by using corrective factors to adapt them to the industrial context. To make possible the application of the method to a large number of major-hazard industry types, some aspects of the approach needed to be improved; these have been identified during a development project coordinated by RINA Consulting, on behalf of Saipem, with the collaboration of the University of Messina. The improvement of the approach focused on two main points, the development of a method to calculate the corrective factors for the failure causes associated with corrosion and erosion phenomena and the strengthening of the methodology for the formulation of the judgment about the safety management. This paper illustrates the fully improved method, as well as an application to a typical gas storage plant.     

松花江鱼类肌肉中污染物的分析监测

分析研究了松花江吉林市至三岔河口江段鱼类肌肉中43种污染物,结果表明:该江段鱼类已受到总汞、甲基汞、铜、锌、镉和铬的轻度污染,尚未受到铅、锰、铁、砷的污染。扶余至三岔河口江段的鱼类食之有异味,肌内中烷烃、芳烃、硝基芳烃、硝基氯苯和挥发酚5类28种有机污染物的总平均含量和其中的3种促癌或助癌物、6种可疑致癌物以及化工污染的特征性有机污染物──硝基芳烃类的平均含量均比其它江段高。      

温度、氨对鲢、鳙、草、鲤鱼的影响

为制定热排放标准的需要,用动态实验和静态实验方法研究了热冲击与氨对鲢、鳙、草、鲤鱼的急性和亚急性效应。结果表明：选择温度与起始致死温度（TL₅₀）值随着驯化温度的升高而增大,鳙鱼对热冲击的反应较敏感。氨对鲢、鳙、鲤鱼的急性毒性（96h）LC₅₀值分别为0.38、0.30、0.66mgNH₃/L（非离解氨）。水温升高5℃,鲤鱼的（96h）LC₅₀。值从0.66mgNH₃/L下降到0.44mgNH₃/L,热冲击明显提高了氨对鲤鱼的毒性。氨对鲤鱼的亚急性毒性结果表明,鳃、肝组织出现了病理改变。以上室内实验结果可作为评价监测热污染水质的科学依据。     

Change in Fish Fauna as Indication of Aquatic Ecosystem Condition in Río Grande de Morelia–Lago de Cuitzeo Basin, Mexico

Chirostoma charari and C. compressum, and they are presumed extinct. Twelve (63%) of the remaining species had declines in distribution. Sixteen (80%) of the 20 localities sampled had lost species. The greatest declines occurred in Lago de Cuitzeo proper and in the lower portion of the Río Grande de Morelia watershed. Species losses from the lake were attributable to drying and hypereutrophication of the lake because of substantial reductions in the amount and quality of tributary inputs, whereas losses from the Río Grande de Morelia watershed were the result of pollution from agricultural, municipal, and industrial sources, especially in the region around the city of Morelia. Three localities in the upper portion of the Río Grande de Morelia watershed—Cointzio reservoir, La Mintzita spring, and Insurgente Morelos stream—contained most of the remaining fish species diversity in the basin and deserve additional protection. Fish faunal changes indicated major declines in the health of aquatic ecosystems in the Morelia–Cuitzeo basin.