隧道衬砌变形的反分析被动抗力法的发展与应用     

Najm  K 张佳文 《探矿工程译丛》1995,(1):57-61

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Assessment of long term change in sediment condition after organic enrichment: defining recovery     

Macleod CK  Crawford CM  Moltschaniwskyj NA 《Marine pollution bulletin》2004,49(1-2):79-88

Sediment condition at an Atlantic salmon (Salmo salar) culture site in S.E. Tasmania, Australia was evaluated to determine the rate and extent of recovery after removal of farmed fish. By local standards the cage sediment at the start of this survey was markedly degraded but comparison with results from impact studies in Scotland, Canada and Norway suggests that the sediments were considerably less impacted than in northern temperate areas. The impact at the cages diminished rapidly with both time and distance; after only 2 months conditions were markedly improved. The macrobenthos indicated a slower recovery than chemical measures, after 36 months the benthic faunal community structure under the cages still differed from reference conditions even though other sediment measures had recovered. This study highlighted two other key issues in relation to monitoring and management of sediment recovery. First, techniques used to determine impact may not be appropriate for evaluation of recovery. Second, establishment of local baseline standards is extremely important to ensure appropriate evaluation of both impact and recovery.  相似文献   

The distribution and inventory of total and methyl mercury in Kuwait Bay     

Butayban NA  Preston MR 《Marine pollution bulletin》2004,49(11-12):930-937

Sediment (surface and core) sampling was conducted during the period from August 96-December 98 from intertidal and offshore areas in Kuwait Bay. The highest (and most variable) concentrations of total mercury (T-Hg; 36500+/-34930 ng g(-1)) are encountered around the previous industrial outfall where sediments are disturbed by shipping activities. The concentrations of T-Hg are lower in the Shuwaikh Port area (650+/-210 ng g(-1)) and continue to decrease towards the northern coastline of Kuwait Bay (average concentrations in the wider Bay region are 50+/-30 ng g(-1)). These values are still above background concentrations of 15-20 ng g(-1). Calculation of the total inventory of mercury in all the surface sediments of the studied area indicates that approximately 22.5 ton is present which is similar to the estimated industrial discharges of approximately 20 ton suggesting that the contamination is largely confined to the Bay and that releases to the wider Gulf region are small. The distributions of MeHg are similar to those of T-Hg and represent ranges between 0.23% and 0.5% of the T-Hg indicating that surface sediments within Kuwait Bay contain approximately 80 kg of this chemical.  相似文献   

Evaluation of short-term fallowing as a strategy for the management of recurring organic enrichment under salmon cages     

Macleod CK  Moltschaniwskyj NA  Crawford CM 《Marine pollution bulletin》2006,52(11):1458-1466

Rotation of cages within fish farm leases and the subsequent fallowing of areas of seabed is commonly used to allow recovery of infaunal communities following periods of organic enrichment. To investigate the effect of different background environmental conditions on recovery response, two Atlantic salmon (Salmo salar) fish farm sites in southeast Tasmania were sampled over two commercial fallowing cycles. Despite similar stocking levels and feed input there were significant differences in the way in which sediment at each farm responded to the cessation of fish stocking. Sediments at both farms showed some improvement in the community structure over a three month fallow period, but the community structure only recovered to that present before stocking not to that at the reference sites. The similarity of the impact sites to the reference sites increased from ca. 25% to 31% at one site and 11% to 27% at the other after fallowing. Rate and extent of recovery were affected by farm location, initial impact of the sediments, and length of fallow period. Initial recovery was faster at the more sheltered site than at the more exposed site, possibly reflecting differences in environmental resilience with the more sheltered location better able to assimilate organic inputs. Accordingly general fallowing management protocols may need to be adapted to reflect differences between sites. The findings of this study suggest that the recovery response of benthic communities can be predicted once baseline conditions are understood.  相似文献   

滇东北镇雄硫磺矿区环境地质问题及其对策与意义     

张佳文  赵元艺  骆检兰  魏友华  方景玲  蔡剑辉  刘冠男  李小赛  崔宁  黄道袤  王蕊  郑权 《地球学报》2019,40(2):329-338

硫磺渣是硫磺矿区主要的矿业固废,其随意堆放可产生一系列的环境地质问题,并对山水林田湖草等自然资源、环境及人的健康构成较大危害。滇东北地区长期以硫铁矿为原料、以煤炭为燃料,土法炼硫生产硫磺,导致巨量硫磺渣堆积,产生了严重的环境地质问题。本文针对该地区镇雄县硫磺矿区,调查了小硫磺生产形成硫磺渣的规模和特征,梳理了该硫磺矿区主要环境地质问题及其对当地生态环境的影响,认为目前镇雄硫磺矿区存在的环境污染、自然资源破坏及可能形成的矿渣性泥石流等环境地质现状与过去40多年的小硫磺生产密切相关。基于以上认识,强调应结合矿业固废无害化、减量化和资源化技术政策,从资源回收利用、生态环境恢复、地质灾害防治和文化遗产保护方面探讨和提出镇雄硫磺矿区矿渣治理和生态修复的新理念和新对策。  相似文献   

有色示踪剂模拟槽实验图像分析法     

赵勇胜  陈震  张佳文  肖乐乐  陈瑾 《吉林大学学报(地球科学版)》2018,48(3):846-853

图像分析法是处理有色示踪剂模拟槽实验结果的常用方法之一。本文以食用亮蓝为示踪剂,从污染物的检测精度和污染羽描绘的准确度两个方面将图像分析法与传统取样法进行对比,并利用Matlab编程对模拟槽内的污染物贮存质量进行定量计算。结果表明,与传统取样法结果相比：图像分析法的检测精度可提高1个数量级;污染羽的描绘准确度至少可提高3%左右,在实验所设置的非均质条件下可提高17%左右。利用自行编制的Matlab程序对本实验模拟槽内贮存亮蓝质量进行计算可得,当剖分格数为3 700²（1 369万）时,亮蓝贮存质量的计算值最接近实测值,最小误差仅为0.5%。综合来讲,图像分析法是一种准确度高、空间分辨率高的信息采集和处理手段,可实现对非均质地层中有色示踪剂运移过程更为精细的描述。  相似文献   

Macrobenthic community structure in the northern Saudi waters of the Gulf, 14 years after the 1991 oil spill   总被引：1，自引：0，他引：1  

Joydas TV  Qurban MA  Al-Suwailem A  Krishnakumar PK  Nazeer Z  Cali NA 《Marine pollution bulletin》2012,64(2):325-335

The 1991 Gulf oil spill heavily impacted the coastal areas of the Saudi waters of the Arabian Gulf and recent studies have indicated that even 15 years after the incident, macrobenthos had not completely recovered in the sheltered bays in the affected region such as, Manifa Bay. This study investigates the community conditions of macrobenthos in the open waters in one of the impacted areas, Al-Khafji waters, about 14 years after the spill. Diversity measures and community structure analyses indicate a healthy status of polychaete communities. The BOPA index reveals that oil sensitive amphipods were recolonized in the study area. This confirms that the benthic communities of the oil spill impacted area had taken only <14 years to recover in the open waters of the impacted areas. The study also reveals the existence of three distinct polychaete communities along the depth and sediment gradients.  相似文献   

Early Cambrian Mollusc Watsonella crosbyi: A Potential GSSP Index Fossil for the Base of the Cambrian Stage 2     

LI Guoxiang  ZHAO Xin  Alexander GUBANOV  ZHU Maoyan  NA Lin 《《地质学报》英文版》2011,85(2):309-319

The mollusc Watsonella crosbyi was studied on the basis of material from the lower Cambrian Dahai Member of the Zhujiaqing Formation in eastern Yunnan, China and the Pestrotsvet Formation of the Aldan River region in the Siberian Platform. This fossil had been excessively described under different names in the literature, such as Heraultia varensalensis Cobbold, 1935, H. sibirica Missarzhevsky, 1974, Heraultipegma yunnanensis He and Yang, 1982, H. yannanese He and Yang, 1982, Watsonella yunnanensis, W. crosbyi Grabau, 1900, etc. Taxonomic revision shows that other species are junior synonyms of W. crosbyi. Analysis of functional morphology implies that W. crosbyi may be rather a helcionelloid than a rostroconch since its univalved conch is untorted endogastric and lacks a rostrum and a true internal pegma. Replicas of the original microstructures preserved on the surfaces of phosphatic internal moulds confirm that the shell consists of two layers. The inner layer is lamello-fibrillar, and the outer layer is spherulitic prismatic. The widespread geographical occurrences in both siliciclastic and carbonate rocks of the late Terreneuvian indicate that W. crosbyi is an important index fossil for global correlations and subdivision of the Cambrian Series 1 (Terreneuvian). The first appearance datum (FAD) of W. crosbyi is suggested to be a potential GSSP (Global Boundary Stratotype Section and Point) candidate marker for defining the base of the Cambrian Stage 2.  相似文献   

隧道工程的土体与岩石加固     

Peliz.  S 张佳文 《探矿工程译丛》1994,(3):58-61

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整体推进 协调发展     

张佳文 《地质科技管理》1997,(4):25-29,15

本文回顾地矿部勘探技术所“八五”期间深化改革、转轨建制、整体推进、协调发展的做法和所取得的成绩。  相似文献