索氏提取-液相色谱法测定土壤中邻苯二甲酸酯类物质

采用索氏提取-固相萃取柱净化分离、高效液相色谱测定土壤中6种邻苯二甲酸酯类物质。利用正交试验对影响加标回收率的3个主要因素(萃取溶剂比例、萃取时间和萃取温度)进行了优化。方法回收率为95.3%～108.0%,相对标准偏差为0.83%～3.53%。并对实际土壤样品进行了测定。     

Temporal and spatial variations in the discharge and dissolved organic carbon of drip waters in Beijing Shihua Cave,China

To detect the causal relationship between cave drip waters and stalagmite laminae, which have been used as a climate change proxy, three drip sites in Beijing Shihua Cave were monitored for discharge and dissolved organic carbon (DOC). Drip discharges and DOC were determined at 0 to 14‐day intervals over the period 2004–2006. Drip discharges show two types of response to surface precipitation variations: (1) a rapid response; and (2) a time‐lagged response. Intra‐annual variability in drip discharge is significantly higher than inter‐annual variability. The content of DOC in all drip waters varies inter‐ and intra‐annually and has good correlation with drip water discharge at the rapid response sites. High DOC was observed in July and August in the three years observed. The flushing of soil organic matter is dependent upon the intensity of rain events. The DOC content of drip water increases sharply above a threshold rainfall intensity (>50 mm d^?1) and shows several pulses corresponding with intense rain events (>25 mm d^?1). The DOC content was lower and less variable during the dry period than during the rainy period. The shape of DOC peak also varies from year to year as it is influenced by the intensity and frequency of rainfall. The different drip sites show marked differences in DOC response, which are dominated by hydrological behaviour linked to the recharge of the soil and karst micro‐fissure/porosity network. The results explain why not all stalagmite laminae are consistent with climate changes and suggest that the structure of the rainy season events could be preserved in speleothems. Copyright © 2008 John Wiley & Sons, Ltd.     

地震异构云管理平台的技术架构设计

基于Open Stack的开源标准体系,结合中国地震台网中心和中国地震局第二监测中心的云基础设施现状,设计两级云管理架构,以异构云管理平台作为综合管理平台,纳管区域云管理平台,以统一门户的方式对地震行业云计算资源进行统一管理;通过容器化部署异构云管理平台,初步实现对地震行业云计算资源的统一监控和运行管理。     

A Social–Ecological Systems Approach to Assessing Conservation and Fisheries Outcomes in Fijian Locally Managed Marine Areas

Locally managed marine areas (LMMAs) are often recommended as a strategy to achieve conservation and fisheries management, though few studies have evaluated their performance against these objectives. We assessed the effectiveness of eight periodically harvested closures (PHCs), the most common form of management within Fijian LMMAs, focusing on two outcomes: protection of resource units and biodiversity conservation. Of the eight PHCs, only one provided biodiversity benefits, whereas three were moderately successful in protecting resource units (targeted fish biomass). Protection of resource units was more likely when PHCs were harvested less frequently, less recently, and when total fish biomass in open areas was lower. Our findings further suggest that monitoring, enforcement, and clearly defined boundaries are critical, less frequent harvesting regimes are advised, and culturally appropriate management incentives are needed. Although PHCs have some potential to protect resource units, they are not recommended as a single strategy for broad-scale biodiversity conservation.     

Seasonal Changes in Nano/Micro-Zooplankton Herbivory and Heterotrophic Nano-Flagellates Bacterivory off Cape Esan, Southwestern Hokkaido, Japan

Seasonal changes in nano/micro-zooplankton grazing on pico-, nano- and micro-size phytoplankton and heterotrophic nano-flagellates (HNF) feeding on heterotrophic bacteria were quantified by the dilution technique in the surface layer off Cape Esan, southwestern Hokkaido, Japan. Pico- and nano-size phytoplankton were major components throughout the year except in spring when a diatom bloom was observed. Although there was little seasonal variation in bacteria and HNF biomass throughout the year, the micro-zooplankton biomass varied appreciably with a peak in spring. Nano/micro-zooplankton grazing or feeding on pico-size chl-a and bacteria were well balanced throughout the year. However, nano-size and micro-size chl-a growth were much greater than grazing in summer. Nano/micro-zooplankton ingestion of phytoplankton was greater than their ingestion of bacteria almost throughout the year, which suggests phytoplankton are more important as food sources of nano/micro-zooplankton in microbial food webs off Cape Esan than bacteria off Cape Esan. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cumulative impact mapping: Advances,relevance and limitations to marine management and conservation,using Canada's Pacific waters as a case study

Analysis of cumulative human impacts in the marine environment is still in its infancy but developing rapidly. In this study, existing approaches were expanded upon, aiming for a realistic consideration of cumulative impacts at a regional scale. Thirty-eight human activities were considered, with each broken down according to stressor types and a range of spatial influences. To add to the policy relevance, existing stressors within and outside of conservation areas were compared. Results indicate the entire continental shelf of Canada's Pacific marine waters is affected by multiple human activities at some level. Commercial fishing, land-based activities and marine transportation accounted for 57.0%, 19.1%, and 17.7% of total cumulative impacts, respectively. Surprisingly, most areas with conservation designations contained higher impact scores than the mean values of their corresponding ecoregions. Despite recent advances in mapping cumulative impacts, many limitations remain. Nonetheless, preliminary analyses such as these can provide information relevant to precautionary management and conservation efforts.     

白令海底栖生物体内的Cd、Cu、Cr、Zn含量及其生物富集作用

The Bering Sea is an area of high biological productivity, with large populations of sea-birds, demersal and pelagic fishes, so it seemed desirable to assess the bioaccumulation of trace metals in the ...     

气相色谱-质谱法测定水中8种多氯联苯

以正己烷为提取剂,对水中PCB15、PCB28、PCB52、PCB101、PCB118、PCB138、PCB153、PCB180共8种多氯联苯(PCBs)单体经液-液提取、浓缩后,采用气相色谱-质谱联用选择离子扫描法测定,8种PCBs单体的检测限均小于2.5ng/L。低浓度PCBs的回收率为88.5%～104.0%,相对标准偏差(RSD,n=5)为3.5%～9.7%;高浓度PCBs的回收率为90.3%～102.0%,相对标准偏差(n=5)为2.6%～8.3%。方法具有良好的灵敏度和选择性,适用于批量水样中多氯联苯的测定。     

Studies on groundwater recharge characteristics at a reclaimed land site with an equatorial climate using time‐series and spectral analyses

Groundwater recharge studies are essential for investigating the feasibility of using the reclaimed lands in Singapore for subsurface storage and recovery of water. Through time‐series and spectral analyses, net recharge percentages and stress‐filtering characteristics at the reclaimed land were found to depend strongly on the stress transfer velocity, which was a combined function of rainfall pattern and vadose zone thickness. Based on stress transfer velocity, a theory was established to provide logical explanations for the rainfall–recharge relationship, the observed stress‐filtering characteristics and the recharge percentage characteristics at the unconfined sandy aquifer. Although the reclaimed land site has a lithollogically homogeneous soil profile, a non‐uniform recharge pattern was observed to be influenced pronouncedly by the uneven density distribution of bush grasses. Under a bare soil condition, significantly lower recharge percentages were observed for areas under the influence of offshore tides. The unconfined sandy aquifer appears to dampen out the wave propagation of offshore tides rapidly within a short distance from the tidal source, though it has a fairly straight shoreline and is created from highly compacted sand fills. Copyright © 2006 John Wiley & Sons, Ltd.     

湖泊沉积物中蛋白质和氨基酸的动态变化

测定了阿哈湖和百花湖沉积物孔隙水中蛋白质和氨基酸的含量。蛋白质含量分别在0．32－1．71mg/ml和0．22－1．38mg/ml之间，氨基酸含量分别在1．15－5．01μg/ml（以含N量计）和1．41－4．16μg/ml之间。两湖沉积物氨基酸含量逐渐增高，表明扩散作用的存在。随着时间的推移，蛋白质在沉积物各层中得到了很好的保存，说明它的分解比较有限。沉积物孔隙水中氨基酸含量和微生物活动有关，氨基酸在27cm以后的阿哈湖沉积物中明显积累，可能指示微生物活动的减弱。