ENSO循环过程对南极海冰的影响

应用 1 951- 2 0 0 2年NINO特征指数 (NINO1 +2 ,NINO3 ,NINO4 ,NINO3 .4)和 1 973-1 998年南极海冰北界范围以及 1 950- 2 0 0 1年SODA海洋温度资料。首先分析探讨了在ElNi no期间 ,堆积于赤道东太平洋的异常暖水在南半球的传播途径 ,进而研究了ENSO以及东南太平洋异常海温场与南极海冰之间的关系。结果表明 ,在ElNino期间 ,堆积于赤道东太平洋的异常暖水 ,是沿秘鲁和智利沿岸向极传播。其传播过程持续大约 1年的时间 ,但未发现沿南赤道流的西传现象。ENSO循环过程与南极海冰变化存在一定联系 ,特别是Amundsen Belling shausen海和南极半岛海冰的变化与ENSO暖事件 (ElNino)较为密切。当ElNino事件发生后 ,时滞 2年左右的时间 ,Amundsen Bellingshausen海和南极半岛的海冰将出现明显的减少现象 ,特别是南极半岛的海冰减少最为明显。ElNino事件对南极海冰的影响过程是 ,堆积于赤道东太平洋的大量异常暖水 ,沿南美 (秘鲁和智利 )沿岸近海向极地传播 ,异常暖水的这种向极传播过程将引起近极的海温场出现异常升高 ,最终导致Amundsen Bellingshausen海和南极半岛地区的海冰减少。自 2 0世纪 80年代以来 ,Amundsen Bellingshausen海和南极半岛的海冰出现明显减少的趋势 ,与这一时期的ElNino事件的频繁发生     

北极海冰细菌产胞外酶及主要环境因子的初步研究

覆盖在北极海洋上的广阔海冰为其内部生存的微生物群落提供了一个独特的生境。研究表明 ,大量海冰细菌能够分泌产生胞外酶 ,其中产蛋白或脂质水解酶细菌的比例远高于产多糖水解酶的细菌。温度、盐度是直接影响海冰细菌生存与活力的 2个主要环境因子。 76%的产酪蛋白酶海冰细菌为低温菌 ,菌株只能在 <35°C条件下生长 ;而 98%的酪蛋白酶最适作用温度≥ 35°C ,其中 62 %的酶最适作用温度≥ 45°C。几乎所有的产酪蛋白酶海冰细菌都耐盐或嗜盐     

Fire Severity,Water Repellency Characteristics and Hydrogeomorphological Changes Following the Christmas 2001 Sydney Forest Fires

Soil water repellency can enhance overland flow and erosion and may be altered by fire. The Christmas 2001 bushfires near Sydney allowed investigation of the relationship between fire severity, water repellency and hydrogeomorphological changes. For two sub-catchments with differences in fire severities in Nattai National Park, south-west of Sydney, this paper considers: (1) the links between fire severity based on SPOT image analysis and ground observation of fire severity and repellency; (2) the textural and organic/minerogenic characteristics of eroded sediment; and (3) erodibility, erosion and deposition of soils in both catchments. Ground surveys show that image analysis reflects well the degree of vegetation consumption by fire, but cannot adequately predict the degree of ground litter consumption, associated soil heating and repellency effects. Fire had varying effects on repellency, leaving it unchanged, destroying it or enhancing it, depending on the soil temperature reached. The main post-fire hydrogeomorphological changes have been widespread erosion and colluvial and alluvial deposition of topsoil in foot-slope locations and river systems, but only localised redistribution of the highly erodible, repellent sandy subsurface layer. The fire did not trigger major geomorphological change in the study area, but fires probably cause important topsoil and nutrient depletion and may also affect water quality.     

Transition and Diversity in Rural Housing Provision: The case of Narrogin,Western Australia

The purpose of this paper is to examine the changing dynamics of housing markets in an Australian rural community. With reference to the case of Narrogin, Western Australia, it argues that there is an increasing disjuncture between the social and demographic characteristics of rural residents and the modal form of housing in country towns, namely the detached family house. Factors contributing to this disjuncture include the ageing of the population, the loss of traditional blue-collar employment, sub-regional restructuring of service provision, retirement migration patterns, and growing acceptance of the particular housing needs of groups such as the aged, the disabled, young and indigenous people. While it is clear that there is currently something of a mismatch between the characteristics of the population and the housing stock in Narrogin, it is also evident that a combination of political, cultural and economic factors form a significant barrier to adjustment in the local housing market.     

Population and environment in Australia: issues in the next half century

This paper considers the likely future population in Australia to 2050 and is cast within the context of environmental limitations, to which Griffith Taylor alerted the nation in the 1920s and 1930s, and for which he was vilified in several quarters. While acknowledging the relative accuracy of his long-range forecasts, the arguments here depart from environmental determinism, although varying sets of environmental ethics and values are considered in relation to Australia's global responsibilities and international commitments. It is argued that an increase in population to 26 million by 2050 will not place severe stresses on the physical environment, provided environmental and resource management strategies are put firmly in place, and if consumption and resource use practices are significantly modified. An ideological linkage exists between a resurgent Australian nationalism and a number of environmental perspectives, but one which rejects growth and biological diversity among humans while embracing environmentalism. This inward-looking nationalism–environmentalism is seen as harmful both to Australia's moral integrity as a nation, and in local and world citizenship.     

Re-placing the Pilbara's mining unions

This paper examines the attempt by mining management in Western Australia's Pilbara to replace mining unions—quite literally—by removing them from the processes of representation and bargaining. It analyses the way in which those unions have tried to re-place themselves, in the senses of transforming themselves in those spaces in which they were already operating and reviving themselves where they were not. Where unionists have succeeded in these engagements, it has been by working at a range of geographical scales, using the ‘power of place’ in the Pilbara and reshaping traditional geographies of union organisation. It is suggested here that many of these emergent outcomes are the result of the embeddedness of geographically specific historical structures along with new intersections of nationally and locally scaled labour politics.     

The ins and outs of skateboarding and transgression in public space in Newcastle,Australia

This study examines skateboarding as a transgressive activity in different inner Newcastle public spaces, highlighting the way certain places are constructed, and the values and meanings attached to them. Skateboarding has been sanctioned in some places, but is considered to be inappropriate in others, resulting in the implementation of skating restrictions in specific areas. Transgressive conduct is different from the norm and appears to be ‘out of place’. However, labels of ‘in’ and ‘out’ of place are too simplistic, because transgression is more nuanced and can simultaneously operate at multiple scales. Some skateboarding activities and locations are seen as more legitimate than others, and so a skater can be both ‘in place’ and ‘out of place’ at the same time. Problems and inconsistencies in the regulation of public space are revealed, because although skateboarding may be illegal in some places, the regulations are blunted by limited enforcement, justified by distinctions between ‘good’ and ‘bad’ skateboarding.     

测氡在滑坡研究中的应用

测氡是一种放射性地球物理方法,利用滑坡体与其周边岩土体的结构差异,应用测氡可对滑坡进行勘探,对滑坡的结构特征进行研究,达到节约投资,缩短勘探时间的目的,并可与地质分析相互验证,为工程应用提供依据。