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41.
François Mialhe Yanni Gunnell Catherine Mering Jean-Christophe Gaillard June Gonzales Coloma Lionel Dabbadie 《Journal of Land Use Science》2016,11(2):236-256
This study documents the event chronology and causes of land-use change in a deltaic region of the Philippines since the beginnings of aquaculture in the late nineteenth century. Satellite images and topographic maps spanning the period 1972–2013 were processed to map fishponds and the natural habitats over which they have encroached. Historical archives were consulted and interviews were conducted to understand the historical exploitation of local natural resources and the reasons behind the recorded land changes. Results showed that aquaculture developed in the late nineteenth century and expanded subsequently across the landscape under a succession of forcing factors. The global market, for example, played an early role but a number of land-use changes were also a direct response to changing environmental constraints and natural hazards. These cumulative events have promoted continuous gain in favor of aquaculture, to the detriment of other land-use options. 相似文献
42.
饮用水中的消毒副产物及其控制策略 总被引:1,自引:1,他引:0
消毒副产物(disinfection by-products,DBPs)是在饮用水消毒时由消毒剂与有机或无机前体物反应生成的一类次生污染物,其由于具有致癌、致畸和致突变的三致特性在全球范围内广受关注.聚焦于饮用水中的DBPs,介绍了DBPs的主要分类和研究历程,汇总了多地饮用水中常见DBPs的浓度水平以及全球饮用水水质标准对DBP指标的管控要求.随后系统介绍了饮用水中DBPs的控制策略,包括源头控制、过程控制、末端控制以及协同控制这4大类,并对各类控制方法的优缺点进行了分析.评述了中国的DBPs研究的现有水平和未来趋势,并展望了未来有关DBPs控制方法的研究方向.一方面,在评价某种工艺或技术对DBPs的控制效果时需要考虑DBPs浓度和水质综合毒性的变化,另一方面,建议关注耦合源头、过程和末端控制技术的协同控制方法,兼顾从源头到龙头每个节点,实现对饮用水中各类DBPs的高效控制. 相似文献
43.
亚热带常绿阔叶林下分布着可塑性强的耐荫植物,其叶片应对外界干扰的防御对策至少有物理性防御和化学性防御两种,这两种防御代价在一定的昆虫取食压力下在理论上应该存在权衡.为检验这种权衡是否普遍存在,分别测定了重庆缙云山4个常绿物种——光叶山矾(Symplocos lancifolia)、四川山矾(S.setchuensis)、四川毛蕊茶(Camellialawii)和细枝柃(Eurya loquaiana)在林窗和林下两种对照光环境下个体叶片的光饱和下的净光合速率、叶面积干重和部分化学防御物质含量.结果表明,4个物种生活在林窗的个体单位叶面积干重、叶片氮含量和单位面积净光合速率通常高于林下的个体,但是单位质量和单位面积的总酚含量和C/N值却低于林下的个体.蛋白质和非结构性碳水化合物含量在不同生境中没有显著差异.因为不同物种叶片对光照条件的响应不同,不同参数的变化在两种生境间的差异并不完全一致.本研究结果在一定程度上暗示了物种在林窗和林下分别倾向于采取物理和化学性防御对策,并初步证实了两种防御强度之间存在权衡关系.图4参40 相似文献
44.
45.
Kasim A. Korkmaz Ali SariAsuman I. Carhoglu 《Journal of Loss Prevention in the Process Industries》2011,24(4):314-320
In 1999, two earthquakes in northwest Turkey caused heavy damage to a large number of industrial facilities. This region is the most industrialized in the country, and heavy damage has a significant economic influence. Industrial storage tanks, ruptured by earthquakes, exascerbate damage through the spread of fire. Storage tanks are uniquely structured, tall cylindrical vessels, some supported by relatively short reinforced concrete columns. The main aim of this study is to evaluate the earthquake performance of Turkish industrial facilities, especially storage tanks in terms of earthquake resistance. Modeling a typical storage tank of an industrial facility helps to understand the structure’s seismic response. A model tank structure was modelled as a solid with lumped mass and spring systems. Performance estimation was done with 40 different earthquake data through nonlinear time history analyses. After the time history analyses, fragility analyses produced probabilistic seismic assessment for the tank model. For the model structure, analysis results were evaluated and compared. In the study, vulnerability of storage tanks in Turkey was determined and the probabilistic risk was defined with the results of the analysis. 相似文献
46.
47.
Hub Zwart 《Journal of Agricultural and Environmental Ethics》2000,12(2):113-126
Moral concern with food intake is as old asmorality itself. In the course of history, however,several ways of critically examining practices of foodproduction and food intake have been developed.Whereas ancient Greek food ethics concentrated on theproblem of temperance, and ancient Jewish ethics onthe distinction between legitimate and illicit foodproducts, early Christian morality simply refused toattach any moral significance to food intake. Yet,during the middle ages food became one of theprinciple objects of monastic programs for moralexercise (askesis). During the seventeenth andeighteenth century, food ethics was transformed interms of the increasing scientific interest in foodintake, while in the nineteenth century the socialdimension of food ethics was discovered, with theresult that more and more attention was given to theproduction and distribution of food products. Becauseof the increasing distance between the production andconsumption of food products ever since, theoutstanding feature of contemporary food ethics is itreliance and dependence on labeling practices. 相似文献
48.
Lisa E. Schwanz 《Behavioral ecology and sociobiology》2008,62(8):1351-1358
Parasitized animals may alter their life histories to minimize the costs of parasitism. Organisms are predicted to decrease
investment in current reproduction when parasitism has the greatest impact on current reproductive ability. In contrast, if
parasitism decreases residual reproductive value, hosts should increase current reproductive investment, referred to as fecundity
compensation or terminal investment. In mammalian hosts, parasitic infection most often leads to reductions in current host
reproduction, perhaps attributable to the emphasis on parasites that are unlikely to impact the host’s residual reproductive
value. In this study, the life history response of a rodent, Peromyscus maniculatus, to infection with a parasite that should strongly impact the residual reproductive value of its host (Schistosomatium douthitti, Trematoda) was examined. Infection decreased survival for hosts exposed to a high dose of parasites and was chronic in survivors,
confirming that infection had strong impacts for the residual reproductive value of the host. As predicted, infected mice
increased their reproductive output, producing litters of greater mass due to heavier offspring. However, this increased output
was observed after a greater delay to begin breeding in infected mice and was not observed in animals that suffered early
mortality. The deer mouse S. douthitti system may provide a rare example of fecundity compensation in mammals. 相似文献
49.
Female and male reproductive interests often differ. In species in which matings are accompanied by a transfer of resources
valuable for both participants, such as nuptial prey gifts, conflicts may readily occur. Scorpionflies may use alternative
mating tactics. One is to offer a prey item (dead arthropod) to females in exchange for mating. This prey gift tactic includes
a conflict because a male must decide on whether to offer the gift rather than to fight the female and consume the gift. The
outcome may depend on the nutritional status of both males and females. Males may be more willing to give if they themselves
are satiated and the condition of the females may influence the payoff from the males’ investment. Similarly, females may
be more willing to accept food gifts if they are in poor nutritional condition. In this study of the scorpionfly Panorpa cognata, I experimentally manipulated the feeding history of both males and females. I observed the outcome of the direct interactions
that followed when males that were holding prey were approached by females. I found that well-fed males offered the food gift
sooner than males in poor nutritional condition that fed extensively on the food item before offering. Female condition had
no significant influence on whether prey items were offered by males or accepted by females. I also found that well-fed males
rarely searched for prey to pursue the prey gift tactic in courtship. Thus, the prey tactic does not seem to be the males’
first option. 相似文献
50.
浅谈音乐与体育之缘 总被引:2,自引:0,他引:2
张家凤 《中国环境管理干部学院学报》2006,16(2):123-125
音乐与体育作为人类社会独特的文化现象,在不同时期以各种形式相互融合,共同构成人类自身情感的表达方式,成为“世界语言”。现代社会,音乐以其特有的审美、教育、娱乐功能对社会的进步和发展起着积极的作用。尤其是音乐与现代奥运会结合,传承了奥林匹克精神,扩大奥运会的影响,展示了民族的文化,让我们真实地感受到一种前所未有的改变世界的力量。 相似文献