渔业污染事故的应急监测

简述我国渔业污染现状,分析突发性污染死鱼事件的管辖权问题和一般分类,提出突发性污染死鱼事件应急监测的实施和要求.     

Canopy structure versus physiology effects on net photosynthesis of mountain grasslands differing in land use

The present paper aims at investigating how changes in canopy structure and species physiology associated with the abandonment of mountain meadows and pastures affect their net photosynthesis. For this purpose, a multi-layer vegetation–atmosphere transfer (VAT) model is employed, which explicitly takes into account the structural and functional properties of the various canopy components and species. Three sites differing in land use are investigated, a meadow, a pasture and an abandoned area. Model simulations agree reasonably with measured canopy net photosynthetic rates, the meadow featuring the highest daily net photosynthesis, followed by the pasture and, finally, the abandoned area. A detailed process analysis suggests this ranking to be mainly due to bulk canopy physiology, which decreases from the meadow to the pasture and the abandoned area, reflecting species composition and species-specific photosynthetic capacities. Differences between the canopies with regard to canopy structure are found to be of minor importance. The amounts of green, photosynthetically active plant matter are too similar at the three sites to be a major source of variation in net photosynthesis. Large differences exist between the canopies with regard to the amount of photosynthetically inactive phytoelements. Even though a model analysis showed them to be potentially important, most of them are accumulated close to the ground surface, where they exert little influence on canopy net photosynthesis.     

Low levels of toxic elements in Dead Sea black mud and mud-derived cosmetic products

Natural muds used as or in cosmetics may expose consumers to toxic metals and elements via absorption through the skin, inhalation of the dried product, or ingestion (by children). Despite the extensive therapeutic and cosmetic use of the Dead Sea muds, there apparently has been no assessment of the levels of such toxic elements as Pb, As, or Cd in the mud and mud-based products. Inductively coupled plasma mass spectrometry analysis of eight toxic elements in samples collected from three black mud deposits (Lisan Marl, Pleistocene age) on the eastern shore of the Dead Sea in Jordan revealed no special enrichment of toxic elements in the mud. A similar analysis of 16 different commercial Dead Sea mud cosmetics, including packaged mud, likewise revealed no toxic elements at elevated levels of concern. From a toxic element standpoint, the Dead Sea black muds and derivative products appear to be safe for the consumer. Whatever the therapeutic benefits of the mud, our comparison of the elemental fingerprints of the consumer products with those of the field samples revealed one disturbing aspect: Dead Sea black mud should not be a significant component of such items as hand creams, body lotions, shampoo, and moisturizer.     

Changes in quality of groundwater with seasonal fluctuations: an example from Ghor Safi area, southern Dead Sea coastal aquifers, Jordan

Introduction The alluvial fan along the eastern and southern m argins of the D ead Sea (hereafter denoted D S) consists of fine to coarse-grained siliclastic sand and pebble-size gravel w ith thin intercalations of lam inated m arl of H olocene age (Pow e…     

Identifying Conservation and Restoration Priorities for Saproxylic and Old-Growth Forest Species: A Case Study in Switzerland

Saproxylic (dead-wood-associated) and old-growth species are among the most threatened species in European forest ecosystems, as they are susceptible to intensive forest management. Identifying areas with particular relevant features of biodiversity is of prime concern when developing species conservation and habitat restoration strategies and in optimizing resource investments. We present an approach to identify regional conservation and restoration priorities even if knowledge on species distribution is weak, such as for saproxylic and old-growth species in Switzerland. Habitat suitability maps were modeled for an expert-based selection of 55 focal species, using an ecological niche factor analyses (ENFA). All the maps were then overlaid, in order to identify potential species’ hotspots for different species groups of the 55 focal species (e.g., birds, fungi, red-listed species). We found that hotspots for various species groups did not correspond. Our results indicate that an approach based on “richness hotspots” may fail to conserve specific species groups. We hence recommend defining a biodiversity conservation strategy prior to implementing conservation/restoration efforts in specific regions. The conservation priority setting of the five biogeographical regions in Switzerland, however, did not differ when different hotspot definitions were applied. This observation emphasizes that the chosen method is robust. Since the ENFA needs only presence data, this species prediction method seems to be useful for any situation where the species distribution is poorly known and/or absence data are lacking. In order to identify priorities for either conservation or restoration efforts, we recommend a method based on presence data only, because absence data may reflect factors unrelated to species presence.     

关于死海地区臭氧耗损现象(ODEs)的研究综述

自1997年在死海地区的大气边界层中观测到午间臭氧浓度迅速下降的现象后,研究学者们即对该地区的臭氧耗损现象(ozone depletion events,简称ODEs)展开了研究.而在此之前,大气边界层内的ODEs现象普遍被认为只会发生在极地地区的特殊大气现象.本文综述了关于死海地区ODEs研究的发展历史,主要展示了促...     

大吨位桥式起重机主梁静刚度检测方法

探索了一种基于弹性理论的桥式起重机静刚度的近似测量方法,可大幅度减轻配重工作的难度并在现场检测中得到应用。     

灭活性产黄青霉菌对铅的吸附研究

本文通过某制约厂青霉素车间排放手大量灭活性产黄青霉菌对溶液中铅的吸附研究，发现该菌体对金属离子吸附有较强的选择性，尤其对铅离子高于其它金属离子。而且被吸附的铅离子能被重新洗脱回收。     

Water input requirements of the rapidly shrinking Dead Sea

The deepest point on Earth, the Dead Sea level, has been dropping alarmingly since 1978 by 0.7 m/a on average due to the accelerating water consumption in the Jordan catchment and stood in 2008 at 420 m below sea level. In this study, a terrain model of the surface area and water volume of the Dead Sea was developed from the Shuttle Radar Topography Mission data using ArcGIS. The model shows that the lake shrinks on average by 4 km²/a in area and by 0.47 km³/a in volume, amounting to a cumulative loss of 14 km³ in the last 30 years. The receding level leaves almost annually erosional terraces, recorded here for the first time by Differential Global Positioning System field surveys. The terrace altitudes were correlated among the different profiles and dated to specific years of the lake level regression, illustrating the tight correlation between the morphology of the terrace sequence and the receding lake level. Our volume-level model described here and previous work on groundwater inflow suggest that the projected Dead Sea–Red Sea channel or the Mediterranean–Dead Sea channel must have a carrying capacity of >0.9 km³/a in order to slowly re-fill the lake to its former level and to create a sustainable system of electricity generation and freshwater production by desalinization. Moreover, such a channel will maintain tourism and potash industry on both sides of the Dead Sea and reduce the natural hazard caused by the recession.     

Changes in quality of groundwater with seasonal fluctuations： an example from Ghor Sail area, southern Dead Sea coastal aquifers, Jordan

The demand for water resources in the area south of the Dead Sea due to continued development, especially at the Arab Potash Company （APC） for production and domestic purposes necessitates that water quality in the area be monitored and evaluated based on the local geology and hydrogeology. The objective of this paper is to monitor seasonal fluctuations of groundwater and to determine how fluctuation in the water levels will affect the groundwater quality. Groundwater levels were found to be influenced by rainfall and pumping of water from the wells for domestic and industrial use. Twenty water samples were collected from different wells and analyzed for major chemical constituents both in pre- and post-seasons to determine the quality variation. Chemical constituents are significantly increased after post-season recharge. According to the overall assessment of the area, water quality was found to be useful for drinking, irrigation and industry.