海洋-声学-探测模型的并行预报技术研究

针对声纳探测性能预报的需求,建立了海洋-声学-探测模型,实现了并行计算。该模型将海洋数值预报模式、声学模式与海洋观测资源进行整合,辅以战术需求,实现了对水声环境和声纳探测性能的动态预报和估计。同时,结合高性能计算机系统,设计并实现了模型的并行算法,结果表明,该程序具有较高的并行性能,较好地满足了声纳探测性能预报对实效性的要求,为形成业务化海洋水声环境预报能力打下了良好的基础。     

面向21世纪的地貌学教学改革的几点思考

地貌学是自然地理学中重要的传统分支学科之一。在跨入新世纪的今天 ,高校地貌学教学亟待改革。笔者认为 ,教学改革不应囿于形式 ,而应注重实质。从培养学生坚实的专业基础考虑 ,教学改革的指导思想应是加强基础教学。教学内容的更新是其中心环节 ,首先是要加强和拓展基础理论 ,其次应密切联系实际 ,突出应用性和环境教育。面对教学内容与课时不足的矛盾 ,应积极进行教法的改革和完善。     

Hydrochemical indexes of seawater intrusion and comprehensive judgement on intrusive degree

１ＴＨＥＨＹＤＲＯＣＨＥＭＩＣＡＬＩＮＤＥＸＥＳＦＯＲＴＨＥＪＵＤＧＥＭＥＮＴＯＮＳＥＡＷＡＴＥＲＩＮＴＲＵＳＩＯＮＴｈｅｈｙｄｒｏｃｈｅｍｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｉｓｔｈｅｄｉｒｅｃｔｂａｓｉｓｆｏｒｔｈｅｊｕｄｇｅｍｅｎｔｏｎｓｅａ...     

延安城区地下水动态及影响因素分析

依据大量地下水监测及开发利用等实测资料,对延安城区地下水动态特征和规律进行分析总结,对影响地下水位的因素采取分类剖析,认为单纯从气象因素看,降水是影响地下水的最重要因素,蒸发次之;而人为开采因素则是地下水持续下降的根本影响因素。为今后该地区的地下水资源开发利用和保护提供科学依据。     

1961-2013年东北与华北气温变化速度空间差异

全球气候的不断变化使得生物生境受到极大影响。气温作为最基本的气候要素,其变化迁移会胁迫生物对此做出响应,造成生物群落的迁徙。气温变化速度将气温看作物质的运动,能够直观地表示气温时空变化特征,对研究生物分布地理界限变化具有重要的指导意义。本文利用1961-2013年的全国每月平均温度数据集,分析了过去50多年中国东北与华北地区之间气温变化速度的区域差异。结果表明：东北与华北两地区整体气温变化速度均值为5.60 km/year,速度范围主要集中于0~9 km/year之间,约占总数的90%。东北地区气温变化速度均值大于华北地区。其中,东北速度均值为5.85 km/year,华北为5.41 km/year。从区域内部来看,东北地区气温变化速度整体较高,三省中黑龙江与吉林速度较高,辽宁省速度变化相对较小。华北气温变化速度高值区域主要分布在内蒙古高原与河北、天津的小部分地区,其他地区的气温变化速度则相对较小。     

全站仪免棱镜测绘线路横断面

测绘横断面是线路勘测的重要工作之一,若能准确、快速测绘横断面会取得显著的经济效益。介绍了全站仪免棱镜测量的基本原理,并对其测量精度作了分析,论述其在较差的测量条件下,简捷、高效、准确测绘横断面的具体应用和注意事项,具有实际指导意义。     

Comparison of the role of two Spartina species in terms of phytostabilization and bioaccumulation of metals in the estuarine sediment

In the joint estuary of the Odiel and Tinto rivers (SW Spain), the invasive Spartina densiflora Brongn. and the native Spartina maritima (Curtis) Fernald are growing over sediments with extreme concentrations of heavy metals. The contents of As, Cu, Fe, Mn, Pb and Zn were determined in sediments, rhizosediments and different tissues of both species, from Odiel and Tinto marshes. S. densiflora showed a higher capability to retain metals around their roots and to control the uptake or transport of metals, mediated by a higher formation of plaques of Fe/Mn (hydro) oxides on the roots. At the Tinto marsh, there were no differences between the metal concentrations of the sediment and those of the rhizosediment, a fact that could be explained by the extremely high concentrations of metals which can pass over a threshold value, altering the properties of root cells and preventing roots from acting as a ‘barrier’ to the uptake or transport of metals.     

Quantifying potential recharge in mantled sinkholes using ERT

Potential recharge through thick soils in mantled sinkholes was quantified using differential electrical resistivity tomography (ERT). Conversion of time series two-dimensional (2D) ERT profiles into 2D volumetric water content profiles using a numerically optimized form of Archie's law allowed us to monitor temporal changes in water content in soil profiles up to 9 m in depth. Combining Penman-Monteith daily potential evapotranspiration (PET) and daily precipitation data with potential recharge calculations for three sinkhole transects indicates that potential recharge occurred only during brief intervals over the study period and ranged from 19% to 31% of cumulative precipitation. Spatial analysis of ERT-derived water content showed that infiltration occurred both on sinkhole flanks and in sinkhole bottoms. Results also demonstrate that mantled sinkholes can act as regions of both rapid and slow recharge. Rapid recharge is likely the result of flow through macropores (such as root casts and thin gravel layers), while slow recharge is the result of unsaturated flow through fine-grained sediments. In addition to developing a new method for quantifying potential recharge at the field scale in unsaturated conditions, we show that mantled sinkholes are an important component of storage in a karst system.     

Integrated use of biomarkers (acetylcholinesterase and antioxidant enzymes activities) in Mytilus galloprovincialis and Mullus barbatus in an Italian coastal marine area

The use of biomarkers to evaluate the biological effects of chemical pollutants in marine organisms represents a recent tool in the monitoring field responding to the need to detect and assess the effects of chemical contaminants on the biota. The aim of the present work was the field application of the integrated use of acetylcholinesterase (AChE) and antioxidant enzymes (catalase--CAT, glutathione peroxidase--GSH-Px), for detecting the possible exposure/effect induced by chemical pollutants in native marine organisms from a coastal marine area, represented by Salento Peninsula (Italy), that shows a coastline of high environmental value, but under constant urban pressure, including agriculture activities, widely diffused in the whole hinterland. Eight sampling stations were chosen: four not urbanized areas considered "uncontaminated" controls and four clearly exposed to anthropogenic impact. The bioindicator species studied were a sessile invertebrate, Mytilus galloprovincialis, and a benthic teleost fish, Mullus barbatus.AChE activity in M. galloprovincialis revealed significant differences among places; the minimum values observed (3.9+/-1.8 nmolmin(-1)mg(-1)) was about 50% reduced with respect to the maximum found (11.4+/-0.9 nmolmin(-1)mg(-1)). The reduction in AChE activity observed in two control stations could be explained by the leaching of pesticides into the sea from the agricultural lands. Moreover, the inhibition of AChE activity by heavy metals besides pesticides, can also explain the reduction of the enzymatic activity observed in an industrialized and harbour area. In M. galloprovincialis AChE activity showed a significant inverse correlation with catalase activity but not with glutathione peroxidase that did not significantly change in animals sampled from the eight stations. Also in M. barbatus AChE activity showed significant differences among places; it was inversely correlated with liver GSH-Px activity, but not with catalase activity, that did not show any significantly variation in animals sampled in the different stations.In conclusion, the integrated use of AChE and antioxidant enzymes (catalase or glutathione peroxidase) in M. galloprovincialis and M. barbatus, two species living in different compartment of marine coastal ecosystem, can find a useful application within the framework of marine coastal environment monitoring programs for detecting the possible exposure/effect induced by chemical pollutants, including pesticides, on living marine organisms.