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841.
842.
Long ER Dutch M Aasen S Welch K Hameedi MJ 《Environmental monitoring and assessment》2005,111(1-3):173-222
A survey was designed and conducted to determine the severity, spatial patterns, and spatial extent of degraded sediment quality
in Puget Sound (Washington State, USA). A weight of evidence compiled from results of chemical analyses, toxicity tests, and
benthic infaunal analyses was used to classify the quality of sediments. Sediment samples were collected from 300 locations
within a 2363 km2 area extending from the US/Canada border to the inlets of southern Puget Sound and Hood Canal. Degraded conditions, as indicated
with a combination of high chemical concentrations, significant toxicity, and adversely altered benthos, occurred in samples
that represented about 1% of the total area. These conditions invariably occurred in samples collected within urbanized bays
and industrial waterways, especially near the urban centers of Everett, Seattle, Tacoma, and Bremerton. Sediments with high
quality (as indicated by no toxicity, no contamination, and the presence of a relatively abundant and diverse infauna) occurred
in samples that represented a majority (68%) of the total study area. Sediments in which results of the three kinds of analyses
were not in agreement were classified as intermediate in quality and represented about 31% of the total area. Relative to
many other estuaries and marine bays of the USA, Puget Sound sediments ranked among those with minimal evidence of toxicant-induced
degradation. 相似文献
843.
844.
黑岱沟露天煤矿排土场果园景观生态建设研究 总被引:2,自引:0,他引:2
本文通过对黑岱沟露天煤矿开发所形成新的人工环境条件下的气候和土壤等因子分析,应用景观生态学原理,规划建设了以观赏为主的果园观生态建设。通过对所载植果树和其它乔灌木的观测研究,筛选出了适宜于排土场生长的杏树、苹果梨、123苹果、山桃等果树品种,以及油松、旱柳、榆树、沙棘、玫瑰和先辈乔灌木品种,完成了排土场的景观生态建设工作,为矿区大面积土地复垦提供了依据。 相似文献
845.
矿区土地复垦是实现土地可持续利用的重要环节,土地复垦中的资金落实,复垦技术利用关系到复垦工作的成败与进展快慢。 相似文献
846.
Antonio Cao Angela M. Falchi Teresa Tuveri Maria T. Scalas Giovanni Monni Cristina Rosatelli 《黑龙江环境通报》1986,6(3):159-167
In this report we have summarized our experience with the prenatal diagnosis of β-thalassemia in 1000 pregnancies followed at least until 12 months after birth. In the majority of these cases, the thalassemia lesion was the nonsense mutation at the codon corresponding to amino acid 39, which produces the hematological phenotype of β-thalassemia. Fetal blood sampling was carried out by placental aspiration, by which a sufficient amount of fetal blood for analysis was obtained in the majority of cases (99 per cent). The fetal mortality associated with fetal blood sampling was 6·3 per cent. Those placental samples contaminated by maternal cells were successfully purified by Ørskov lysis. Fetal blood was analysed by globin chain synthesis on CM–52 columns, which gave reliable results. Two misdiagnoses (0·2 per cent) have been made of which one was due to a non-globin protein co-migrating with the β-chains while the other resulted from a misclassification of the type of thalassemia segregating in the family. 相似文献
847.
以稀土元素(简称稀土)用量较大的废FCC催化剂和废汽车尾气净化催化剂为研究对象,分析总结了两类废催化剂中稀土的成分和回收方法。从废催化剂中回收稀土普遍采用先浸出、后分离提纯的方法。浸出普遍采用无机酸(多为盐酸),分离方法包括溶剂萃取法、化学沉淀法等,最后经焙烧得到稀土氧化物。为从废催化剂中高效回收稀土,可着重考察新浸出机制的引入、分离方式的选择、分离试剂的应用,以及浸出和分离条件的优化,从而为实现工业化回收提供技术支持。 相似文献
848.
Li Li Shixiao Yu Baoping Ren Ming Li Ruidong Wu Yongcheng Long 《Environmental science and pollution research international》2009,16(4):474-478
Background, aim, and scope The Yunnan snub-nosed monkey is one of the most endangered primates in the world. It is experiencing a range of ongoing threats
and the persisting effects of past disturbances. The prospects for this species are not very optimistic because habitat corridors
are severely damaged by logging, grazing, and mining. Each group of the monkeys in different areas is facing a unique variety
of threats. Based on genetic analysis, Rhinopithecus bieti should be separated into three management units for conservation, of which the Mt. Laojun management unit involves the most
endangered primates. Despite the fact that the vegetation on Mt. Laojun is in a relatively pristine state, only two groups
of monkeys, of a total of fewer than 300, survive in the area. With this paper, we aimed to address the capacity of the monkeys’
habitat at the study site and the possible reasons for the small populations.
Materials and methods Rapid ecological assessment based on a SPOT 5 image and field survey was used to simulate the vegetation of the whole area
based on reference ecological factors of the GIS system. The vegetation map of the site was thus derived from this simulation.
Based on the previous studies, the three vegetation types were identified as the suitable habitat of the monkeys. The confusion
matrix-based field GPS points were applied to analyze the precision of the habitat map. Based on the map of suitable habitat
of the monkeys, the utilization of the habitat and the carrying capacity were analyzed in the GIS.
Results The confusion matrix-based field GPS points were applied to the habitat analysis process, and it was found that the habitat
map was 81.3% precise. Then, with the current habitat map, we found that the mixed forest currently used by the monkeys is
only a very small fraction (2.65%) of the overall potential habitat of the population, while the dark conifer forest is 4.09%.
Discussion Poaching is the greatest short-term threat to this species, particularly in the southern range where local residents have
a strong tradition of hunting. Quite a few individual monkeys are still trapped accidentally due to the high density of traps.
These problems are hard to mitigate because it is difficult to enforce laws due to the extremely rugged terrain.
Conclusions The results show that there is a great ecological capacity of the area for the monkey’s survival and a great potential for
an expansion of the monkey population at the site. Based on the current population and its geographical range, it can be estimated
that the suitable habitat area defined by this study can support more monkeys, about many times the current population. Thus,
at least in the Mt. Laojun Area, poaching pressure is the main factor to be responsible for the low density of Yunnan snub-nosed
monkeys instead of habitat alteration.
Recommendations and perspectives Based on these results, some suggestions relating to conservation can be made: Focus conservation efforts on the current distribution
area of the monkeys and create a 20 km buffer zone; design a long-term plan for the suitable habitat outside the buffer zone
to set up a wildlife corridor in the long run; establish an association for the local hunters exploiting, their knowledge
on the animals to promote monkey conservation and stop poaching. Also, the map derived from the study helps managers to allocate
conservation resources more efficiently and enhances the overall outcomes of conservation measures. 相似文献
849.
垃圾填埋场场址的适宜性评价是生活垃圾填埋场建设和运营的前提和基础。以湖南省永州市坦塘垃圾填埋场为例,在分析研究区的地质与水文地质条件的基础上,确定了填埋场适宜性的影响因素为填埋场规模、运输条件、环境条件、建场条件和地质条件,具体包括填埋场面积及容量、综合路况条件、对地表水体污染的可能性、地形平坦程度以及场地是否处在岩溶区等条件,明确了局部地区岩溶发育是制约其适宜性的主要因素。结合垃圾填埋场的建设情况和相关规范、标准,采用层次分析法对坦塘垃圾填埋场进行适宜性评价。评价结果表明,坦塘垃圾填埋场是一个适宜场地,评价结果与实际情况相符。 相似文献
850.
Y.M. Han S.C. Lee J.J. Cao K.F. Ho Z.S. An 《Atmospheric environment (Oxford, England : 1994)》2009,43(38):6066-6073
A previous study on PM2.5 carbonaceous aerosols measured with the thermal optical reflectance (TOR) method in fourteen Chinese cities is extended by subdividing total EC into char-EC and soot-EC. Average char-EC concentrations show great differences between the fourteen cities and between winter and summer periods, with concentrations of 8.67 and 2.41 μg m?3 in winter and summer, respectively. Meanwhile spatial and seasonal soot-EC variations are small, with average concentrations of 1.26 and 1.21 μg m?3 in winter and summer, respectively. Spatial and temporal distributions of char-EC, similar to EC, are mainly influenced by local fuel consumption, as well as the East Asian monsoon and some meteorological factors such as the mixing height and wet precipitation. The small spatial and seasonal variation of soot-EC is consistent with its regional-to-global dispersion, which may suggest that soot carbon is not local carbon, but regional carbon. Char-EC/soot-EC ratios show summer minimum and winter maximum in all cities, which is in good agreement with the difference in source contributions between the two periods. As OC/EC ratio is affected by the formation of the secondary organic aerosol (SOA), char-EC/soot-EC ratio is a more effective indicator for source identification of carbonaceous aerosol than previously used OC/EC ratio. 相似文献