辽西城子山遗址夏家店下层文化期农业活动特征及环境效应   总被引：2，自引：1，他引：1       下载免费PDF全文

赵克良  李小强  周新郢  孙楠 《第四纪研究》2011,31(1):8-15

以辽西城子山文化遗存剖面为研究对象,运用花粉、炭屑、炭化种子和果壳等指标,重建城子山地区夏家店下层文化期农业活动特征及环境效应.研究显示城子山原生植被主要为松属针叶林,先民采用"刀耕火种"农业模式毁林开荒,导致原生植被消失以及次生榛属灌丛和杂草增加.城子山剖面中禾本科花粉含量峰值与炭屑浓度峰值相对应,表明先民高强度或频...  相似文献   

周期性饥饿再投喂对建鲤（Cyprinus carpio var．Jian）生长、体组成、消化酶的影响          下载免费PDF全文

乔秋实  蒋广震  刘文斌  夏薇  刘兆普 《海洋与湖沼》2011,42(3):367-373

采用周期性饥饿再投喂的方法,研究周期性饥饿再投喂对建鲤（1．5±0．2g）的生长、体组成、消化酶的影响。试验分为10个组,共进行60d。结果表明,在相同的饥饿天数下,延长再投喂天数可以使建鲤的增重率逐渐增加,而且S1F4、S2F8、S4F16组的增重率与对照组无显著性差异（P〉0．05）,9个周期性饥饿再投喂组在摄食期...  相似文献   

Quantifying the value of multi-sectoral marine commercial activity in Ireland   总被引：1，自引：0，他引：1  

Karyn Morrissey  Cathal O’Donoghue  Stephen Hynes 《Marine Policy》2011

The realisation that the world’s oceans play an important role in climate regulation and many territory activities, notably food production, coupled with economic changes and the rapid advancement in ocean technology have seen a shift in the perception of the importance of marine resources. This increased focus on marine resources means that governments and policy-makers require accessible and reliable information regarding the role of the marine sector. This information may then be used to formulate new environmental and economic policy measures. The aim of this paper is to define, describe and quantify the value of the marine sector in Ireland. This paper outlines a methodology that provides a robust analysis of the Irish marine sector for 2007. It was found that in 2007 the Irish marine sector contributed €1.44 billion in GVA to the wider Irish economy and employed over 17,000 individuals in full time equivalents.  相似文献   

北京城市办公活动空间满意度分析   总被引：2，自引：2，他引：0  

张景秋  郭捷 《地理科学进展》2011,30(10):1225-1232

以北京城市办公集聚区为调查范围,选取公司周边绿化、交通、商业配套设施状况以及公司所在地整体环境感受4项主观评价指标,采取问卷调查方式,对北京城市以写字楼为载体的工作场所满意度进行调查和分析。研究认为,北京城区办公活动空间满意度综合评价良好,其中对商业配套设施最为满意,对绿化状况最为不满。从被调查的6个行政区看,位于前3名的分别是朝阳区、丰台区和东城区,海淀区因交通、商业配套不满意导致其综合评价为合格;从满意度的空间分布来看,北高南低,并向北和东北方向延展,形成岛状和片状高值区,与北京办公集聚区空间分布特点一致。城市工作者需要更加舒适的工作环境,对于北京城市工作场所的满意度研究,将有助于对城市从人的满意度和幸福感出发进行规划和建设。北京城市今后应注重对办公空间的整体规划,并依据功能定位和作用进行重点建设,从地方文化入手建设有中国特色和北京特点的办公空间,以办公空间优化引导北京南北城区之间均衡发展。  相似文献   

长江上游社会经济因子对侵蚀产沙的影响   总被引：1，自引：0，他引：1  

杜俊  师长兴  范小黎  周园园 《地理学报(英文版)》2011,21(2):359-371

In recent years,the role of human activities in changing sediment yield has become more apparent for the construction of hydraulic engineering and water conservation projec-tions in the Upper Yangtze River,but it has not been evaluated at the macro scale.Taking Sichuan Province and Chongqing City as an example,this paper studies the relationship between socio-economic factors and sediment yield in the Upper Yangtze River based on section data in 1989 and 2007.The results show that sediment yield is significantly correlated with population density and cultivated area,in which the former appears to be more closely related to sediment yield.Moreover,in the relation of sediment yield vs.population density,a critical value of population density exists,below which the sediment yield increases with the increase of population density and over which the sediment yield increases with the decrease of population density.The phenomenon essentially reflects the influence of natural factors,such as topography,precipitation and soil property,and some human activities on sediment yield.The region with a higher population density than critical value is located in the east of the study area and is characterized by plains,hills and low mountains,whereas the opposite is located in the west and characterized by middle and high mountains.In the eastern region,more people live on the lands with a low slope where regional soil erosion is slight;therefore,sediment yield is negatively related with population density.In contrast,in the western region,the population tends to aggregate in the areas with abundant soil and water resources which usually lead to a higher intensity of natural erosion,and in turn,high-intensity agricultural practices in these areas may further strengthen local soil erosion.It is also found that popu-lation tends to move from the areas with bad environment and high sediment yield to the areas with more comfortable environment and less sediment yield.The natural factors have greater influence on sediment yield of western region than that of eastern region.Generally,the natural factors play a dominant role on sediment yield in the Upper Yangtze River.  相似文献   

波兰湖泊面积变化因素     

AdamCHOI 《资源与生态学报(英文版)》2011,2(2):175-180

摘波兰北部有众多斯堪的纳维亚冰盖冰期形成的湖泊。通过湖泊区的研究,发现湖泊面积在逐渐减少,甚至导致消失．本文对变化的程度进行了观测,指出影响波兰湖泊面积变化的主要自然与人为因素,包括气候变化、湖盆深度、生物量增长、森林砍伐、水利工程建修、农药利用和排污等。  相似文献   

Assessing the recent (1834 – 2002) morphological evolution of a rapidly prograding delta within a GIS framework: Macquarie Rivulet delta,Lake Illawarra,New South Wales     

C. A. Hopley  B. G. Jones  M. Puotinen 《Australian Journal of Earth Sciences》2013,60(8):1047-1056

The recent morphological evolution of Macquarie Rivulet delta, Lake Illawarra, New South Wales, has been assessed from historical parish maps from 1834, 1892, 1916 and 1927 along with aerial photographs from 1938 to 2002. These images were digitised, georeferenced and analysed in a GIS framework. The 1834 sketch map could not be georeferenced and it was excluded from the calculation of delta progradation areas. Between 1892 and 1927 morphological changes were minimal, probably because the areas were not resurveyed between these map editions. A significant change in morphology between 1927 and 1938 reflects a change in source material from maps to aerial photographs. The research highlights that great care must be taken when utilising historical data. Major morphological changes observed between 1938 and 2002 included the development of a large crevasse splay in the 1960s to 1970s and the abandonment and infilling of the delta's previously active distributary channels. The research shows that the morphological changes observed on the delta can be related to both natural processes and anthropogenic modifications to the catchment and thus could be used in the development of catchment management plans.  相似文献   

Discussion Water-Rock Interaction and Contamination Characteristics of Karst Groundwater in an Urbanized Area     

LAN Jiacheng  REN Kun  HU Ning  WANG Peng 《《地质学报》英文版》2013,87(Z1):637-637

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首钢地区表层土壤重金属的分布特征及污染评价   总被引：2，自引：0，他引：2  

韩鹏  孙天河  袁国礼  黄勇 《现代地质》2012,26(5):963-971

利用多元统计分析和空间分析相结合的方法,分析了首钢地区表层土壤中Fe、Cr、Ni、V、As、Cd、Pb、Cu、Zn、Hg 10种重金属元素的地球化学特征。研究结果表明,10种元素可以归结为4类:第一类Ni、V、As的含量低于自然背景值,主要受成土母质等自然因素的影响;第二类Cd、Cu、Pb、Zn的含量已经超出自然背景值,其中Cu、Pb、Zn属于轻度污染,Cd属于中度污染,这一类元素主要受到交通和冶炼等人为因素的影响,高值区主要分布于居民区;第三类为Fe、Cr,同时受到自然因素和人为因素的共同影响,高值区集中分布在厂区和部分居民区;第四类为Hg,Hg因其是一种非点源污染的元素而单独聚为一类,主要受到人为因素的影响且高值样点位于河流区。总体而言,首钢地区表层土壤已经受到部分污染,需密切关注其对环境的危害及人群的潜在健康风险。本研究对该区域土壤污染风险评价和土地利用规划等具有一定的借鉴意义。  相似文献   

生长断层活动强度定量研究的主要方法评述   总被引：2，自引：0，他引：2  

雷宝华 《地球科学进展》2012,27(9):947-956

目前,定量研究生长断层活动强度的主要方法有生长指数法、古落差法、断层活动速率法、(古)滑距法和断层位移—长度关系分析法等。在前人研究的基础上,对这些方法进行系统的补充和总结。从不同方法的提出、判别、前提假设、优缺点和关系对比等方面,进行介绍和评述。并通过实例分析,用生长指数法、古落差法、断层活动速率法和断层位移—长度关系分析法计算大张坨断层的活动强度,指出不同方法的优缺点。最后对生长断层活动定量研究方法的发展趋势进行了预测,认为生长断层活动定量研究向精度不断提高、多种方法综合运用、对断层活动演化研究更全面、揭示更多的地质和油气信息等方面发展。  相似文献