共查询到7条相似文献,搜索用时 0 毫秒
1.
《Journal of Cleaner Production》2001,9(3):209-217
The main research question of our study was as follows: What opportunities for upgrading material efficiency and waste minimisation can be found in small and medium-sized enterprises (SMEs)? The empirical material consisted of 41 theme interviews in Finnish industrial SMEs. In the article, the SMEs are assigned to four different categories according to their attitudes towards environmental protection. This analysis also explains why SMEs build up environmental management systems (EMSs). The EMSs do not appear to provide much impetus for SMEs to implement waste minimisation. The reduction of wastes in SMEs is driven more by the costs of raw materials than by waste costs. From the standpoint of environmental authorities, it is therefore crucial to find procedures to support SMEs in increasing their efficient use of materials. 相似文献
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How can straw incorporation management impact on soil carbon storage? A meta-analysis 总被引:8,自引:0,他引:8
Fei Lu 《Mitigation and Adaptation Strategies for Global Change》2015,20(8):1545-1568
3.
Lavenda BH 《Die Naturwissenschaften》2002,89(8):329-337
Einstein's assertion that, based on the relativity principle, inertial mass is to be associated with all forms of energy, was contested by Planck, who showed that a transfer of heat is to be associated with a transfer of inertial mass. The equivalence between mass and energy is interpreted in terms of the equivalence of the rate of heating of a body and the rate of increase of its inertial mass. In an adiabatic process, where the proper mass remains constant, it is the heat content, and not the energy, which is conserved because the pressure, and not the volume, is Lorentz-invariant. There are two categories of relativistic quantities: inertial and thermodynamic, which are transformed into one another by the work necessary to keep the body in motion at a constant velocity. In a non-adiabatic process, the rate of heating is Lorentz-invariant, and it must always be greater than the power that it generates. Therefore, the amount of heat developed in the rest frame has a corresponding inertial mass. 相似文献
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The Venetian plain is a densely populated area and one of the most economically competitive regions in Europe. Therefore, a sustainable management of the water resources has to be accomplished to preserve both the social and economic value of this area and the regional environment in accordance with the European water policy directives. This paper presents the analysis of hydrologic and hydrogeological water balances of the high alluvial plain (approximately 790 km2) highlighting some important peculiarities that could be crucial for the local water policy. By focusing on the importance of different water budget components, the obtained results indicate in the irrigation the most relevant component of the aquifer recharge. Thus, the irrigation management policy of the Land Reclamation Consortia strongly influences aquifer recharge. Moreover, future scenarios (2071–2100) for the high Venetian plain are performed taking into account the changes of climate and irrigation policy. The inflow of the aquifer suffers a decrease ranging from 18% in the scenario influenced by climate change to 28% in the scenario affected by both the variations. In particular, the irrigation recharge shows the highest reduction due to both an increase in evaporation, owing to an increase in the surface temperature, or the irrigation methods. Therefore, the irrigation management policy adopted by the Land Reclamation Consortia is a fundamental concern. Changes from surface irrigation to spray or drip irrigation could strongly affect the aquifer recharge. The classical technique of surface irrigation is very useful in terms of aquifer recharge in comparison with drip or spray irrigation. However, it also requires a huge volume of water compared with the minimum desirable streamflow of a river and its management policy. Currently in Italy, the transition from conventional irrigation systems to water saving techniques is favored by the Land Reclamation Consortia in response to European and Italian directives. However, the possible reduction of the aquifer recharge could influence the actual social and economic condition of the Venetian plain because the human and industrial water needs are mostly dependent by groundwater exploitation. Therefore, water saving activities should be accompanied by appropriate corrective actions to reduce the environmental and social impact due to the decrease in aquifer recharge. 相似文献
6.
Hettyey A Laurila A Herczeg G Jönsson KI Kovács T Merilä J 《Die Naturwissenschaften》2005,92(4):188-192
Interpopulation comparisons of variation in resource availability and in allocation patterns along altitudinal and latitudinal gradients allow insights into the mechanisms shaping the life history of animals. Patterns of between-population differences in female life history traits have been studied intensively across a wide range of taxa, but similar investigations in males have remained scarce. To study if testis weight—a measure of reproductive investment—varies on a geographical scale in anurans, we focussed on the variation in relative testis weight (RelTW) and asymmetry in 22 populations of the common frog Rana temporaria along a 1,600-km latitudinal transect across the Scandinavian peninsula. We found that RelTW decreased towards the north. Body mass and body length both had independent positive effects on testes mass. We found evidence for directional asymmetry (DA) in testis weight with the right testis being larger than the left. The level of DA in testis weight was not related to latitude, but both body mass and testes mass had independent positive effects on asymmetry. We discuss the northwards decrease in RelTW in terms of a decreased reproductive investment as a possible consequence of harsher environmental conditions, and perhaps also, weaker sexual selection in the north than in the south. 相似文献
7.
M. Salvy Y. Capowiez Y. Le Conte M. Salvy J.-L. Clément 《Die Naturwissenschaften》1999,86(11):540-543
Varroa jacobsoni is an ectoparasite of honey bees which reproduces in capped brood cells. Multi-infestation is frequently observed in worker
brood and can be interpreted as an aggregative phenomenon. The aim of this study was to determine whether the distribution
of V. jacobsoni in worker brood cells relies on a random or an aggregative process. We studied the distribution of Varroa females in capped worker brood at similar age by comparing, by a Monte Carlo test, the observed frequency distribution of
mites per cell to simulated distributions based on a random process. A complementary approach, using the "nearest neighbor
distances" (NND) with Monte Carlo tests, was investigated to study the spatial distribution (a) between mites in different
cells and (b) between infested cells in brood. The observed distributions did not differ significantly from that expected
by a random process, and we conclude that there is no aggregation during invasion of V. jacobsoni in worker brood.
Received: 29 April 1999 / Accepted in revised form: 26 August 1999 相似文献