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济南市是资源型缺水城市,地表水遭到严重污染,已成为水质型缺水城市,导致地下水超采、地面沉降、泉水停涌等一系列环境、生态、经济问题,水资源已成为制约济南市发展的瓶颈因素.在对济南市水资源现状及相关问题进行详细分析的基础上,提出加强客水资源调用与管理、水资源循环利用、合理制定水价等水资源可持续利用的措施和对策. 相似文献
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The Ethical Contract as a Tool in Organic Animal Husbandry 总被引:1,自引:3,他引:1
Vonne Lund Raymond Anthony Helena Röcklinsberg 《Journal of Agricultural and Environmental Ethics》2004,17(1):23-49
This article explores what an ethicfor organic animal husbandry might look like,departing from the assumption that organicfarming is substantially based in ecocentricethics. We argue that farm animals arenecessary functional partners in sustainableagroecosystems. This opens up additional waysto argue for their moral standing. We suggestan ethical contract to be used as acomplementary to the ecocentric framework. Weexpound the content of the contract and end bysuggesting how to apply this contract inpractice. The contract enjoins us to share thewealth created in the agroecosystem (by ourjoint contributions) by enjoining us to carefor the welfare and needs of the individualanimal, and to protect them from exploitation(just as human co-workers should not beexploited). The contract makes promoting goodanimal welfare a necessary condition forbenefiting farm animals. Animals for their partare guaranteed coverage under the contract solong as they continue to contribute to thesystem with products and services. 相似文献
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山砂是我国西北部矿区地表的主要自然资源之一,但如用其直接作为煤矿注浆防灭火的原料,不仅会造成输送管路的堵塞,还会引起输送管路的严重磨损。为此,首先研究了常见增稠剂羧甲基纤维素、聚丙烯酰胺和聚丙烯酸钠等对砂粒的悬浮性能,实验结果表明它们只能延缓砂粒的沉降。进而从理论上分析了砂粒悬浮的条件,发现具有一定屈服应力的假塑性流体特性的液体才能悬浮砂粒;并且悬浮砂粒粒径越大,所需屈服应力也越大。基于理论分析,研制了具有该特性的浆液,山砂在该浆液中不仅具有良好的悬浮性能,浆液还具有输送阻力小的特性。管道输送试验表明,浆液稳定性和流动阻力符合实际要求。 相似文献
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Water use efficiency (WUE) is an important ecophysiological characteristic of plants, especially in semiarid and arid regions. At the scale of community or ecosystem, WUE is difficult to quantify because the amount of water used per unit dry mass production is a function of microclimatic variables and species composition. In this study, we analyzed corrected intrinsic water use efficiency (IWUE(s)) of grass and shrub species along the western segment of the Northeast China Transect (NECT) and the relationship between IWUE(s) and mean annual rainfall, habitat degradation status, vegetation type, and plant functional type (C3 versus C4) at 22 survey sites. Site intrinsic water use efficiency (IWUE(v)) and its relationship with the aforementioned site variables were analyzed based on species frequencies at each site. First, it was concluded that photosynthetic pathway played a very important role in determining species IWUE(s). Mean IWUE(s) for C4 species was approximately double that of C3 species. Second, mean annual rainfall, vegetation type, and site degradation status significantly affected IWUE(s) (p < 0.01). Mean IWUE(s) at degraded sites was twice as high as that at nondegraded sites. The mean IWUE(s) for meadows was significantly higher than those for other vegetation types (p < 0.05). Third, the frequency of occurrence of C4 plants explained 36% of the variance in IWUE(v) across the survey sites. The mean frequency of C4 occurrence at degraded sites was more than double that at nondegraded sites. Consequently, mean IWUE(v) at degraded sites was more than double that at nondegraded sites. Dominant C4 species in saline-alkaline areas tended to have higher intrinsic WUE than dominant C4 species in sandy shrub communities. 相似文献
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Anders Kullgren Helena Stigson Anders Ydenius Amanda Axelsson Emma Engström Matteo Rizzi 《Traffic injury prevention》2019,20(4):S7-S12
AbstractObjective: The objective of this article is to describe the characteristics of fatal crashes with bicyclists on Swedish roads in rural and urban areas and to investigate the potential of bicycle helmets and different vehicle and road infrastructure interventions to prevent them. The study has a comprehensive approach to provide road authorities and vehicle manufacturers with recommendations for future priorities.Methods: The Swedish Transport Administration’s (STA) in-depth database of fatal crashes was used for case-by-case analysis of fatal cycling accidents (2006–2016) on rural (n?=?82) and urban (n?=?102) roads. The database consists of information from the police, medical journals, autopsy reports, accident analyses performed by STA, and witness statements. The potential of helmet use and various vehicle and road infrastructure safety interventions was determined retrospectively for each case by analyzing the chain of events leading to the fatality. The potential of vehicle safety countermeasures was analyzed based on prognoses on their implementation rates in the Swedish vehicle fleet.Results: The most common accident scenario on rural roads was that the bicyclist was struck while cycling along the side of the road. On urban roads, the majority of accidents occurred in intersections. Most accidents involved a passenger car, but heavy trucks were also common, especially in urban areas. Most accidents occurred in daylight conditions (73%). Almost half (46%) of nonhelmeted bicyclists would have survived with a helmet. It was assessed that nearly 60% of the fatal accidents could be addressed by advanced vehicle safety technologies, especially autonomous emergency braking with the ability to detect bicyclists. With regard to interventions in the road infrastructure, separated paths for bicyclists and bicycle crossings with speed calming measures were found to have the greatest safety potential. Results indicated that 91% of fatally injured bicyclists could potentially be saved with known techniques. However, it will take a long time for such technologies to be widespread.Conclusions: The majority of fatally injured bicyclists studied could potentially be saved with known techniques. A speedy implementation of important vehicle safety systems is recommended. A fast introduction of effective interventions in the road infrastructure is also necessary, preferably with a plan for prioritization. 相似文献
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