首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16篇
  免费   0篇
废物处理   1篇
环保管理   2篇
综合类   1篇
基础理论   7篇
污染及防治   1篇
评价与监测   4篇
  2012年   2篇
  2011年   2篇
  2010年   1篇
  2009年   1篇
  2008年   2篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  1999年   1篇
  1994年   2篇
  1983年   1篇
排序方式: 共有16条查询结果,搜索用时 796 毫秒
11.
Seasonal differences in the locomotor activity pattern of Podarcis sicula held in constant conditions in the laboratory were found to be associated with systematic differences in both the freerunning period of locomotor rhythms () and the circadian activity time (). In order to establish whether the pineal played a role in the control of seasonal changes in circadian parameters, we examined the effects of pinealectomy in constant conditions on the locomotor behavior of lizards displaying the bimodal activity pattern typical of summer. In most lizards pinealectomy lengthened , shortened and abolished the bimodal activity pattern. Pinealectomy induced a sudden transition from the typical locomotor behavior of summer, characterized by a marked bimodal pattern, short and long , to the typical locomotor behavior of autumn, characterized by a unimodal pattern, a long and short . These results demonstrate that the pineal plays a central role in the seasonal reorganization of the circadian system that occurs in P. sicula.  相似文献   
12.
In the last two decades we witnessed a progressive shift in the approach towards the reduction of the impact of natural hazards. From a general reactive approach, focusing on strengthening disaster response mechanisms, we have moved to proactive approaches. There has been recognition that each element of society, from public institutions to private sector, from community-based organizations to every single individual, can make a difference by acting before disasters strike to reduce the associated risks of human and economic losses. This proactive approach can be summarized in three words: Disaster Risk Reduction (DRR).Today, DRR is an approach used in several sectors and research areas. In the Development sphere, DRR is considered a key feature for sustainability of economic and development gains – especially for developing countries. Significantly, the United Nations Global Assessment Report on Disaster Risk Reduction (2009) is titled “Risk and poverty in a changing climate” highlighting the importance of DRR in reducing poverty while being a means to address the challenges posed by adaptation to climate change.This paper, which serves as an introduction to the special issue of Environment Science & Policy on climate change impact on water-related disasters, intends to provide readers with an overview of the main policy frameworks addressing DRR internationally and in Europe. Further, it aims to offer some “food for thought” on the underlying opportunities we have to enhance the resilience of our communities towards the risks posed by weather-related hazards. It stresses the importance of governance of risks, which starts from an effective dialogue between the scientific community and the policy makers: those who have the responsibility to decide on the most cost-effective interventions to address climate change adaptation and risk reduction.  相似文献   
13.
A numerical model for predicting the fate and transport of biodegradable polyester residues in soil, following successive applications of mulch film, was developed and applied. The polymer, applied on surface soil, was assumed to be converted into by-products (monomers), according to a first order kinetics with constant K(1deg). The monomers released were assumed to sorb on soil organic matter (according to a first-order kinetics with constant K(s)), to be leached with the seepage water, through vertical advection and hydrodynamic dispersion, and biodegraded (according to a first-order kinetics with constant K(b)). Results suggested that, to assess a possible build-up of mulch film (as a polymer) on the surface soil, the degradation constant K(1deg) relating the polymer conversion to by-products should be known, whereas the biodegradation constant K(b) indicates there is no danger of groundwater pollution. Likewise, on the basis of by-product concentration in deep soil, soil pollution should not occur.  相似文献   
14.
The use of disposable cutlery in fast food restaurants and canteens in the current management scenario generates mixed heterogeneous waste (containing food waste and non-compostable plastic cutlery). The waste is not recyclable and is disposed of in landfills or incinerated with or without energy recovery. Using biodegradable and compostable (B&C) plastic cutlery, an alternative management scenario is possible. The resulting mixed homogeneous waste (containing food waste and compostable plastic cutlery) can be recycled through organic recovery, i.e., composting. This LCA study, whose functional unit is "serving 1000 meals", shows that remarkable improvements can be obtained by shifting from the current scenario to the alternative scenario (based on B&C cutlery and final organic recovery of the total waste). The non-renewable energy consumption changes from 1490 to 128MJ (an overall 10-fold energy savings) and the CO(2) equivalents emission changes from 64 to 22 CO(2) eq. (an overall 3-fold GHG savings).  相似文献   
15.
The daily pattern of locomotor activity of the ruin lizard Podarcis sicula in its natural environment changes from unimodal in spring (with only one activity peak per day) to bimodal in summer (with two well-separated activity peaks per day) and it becomes unimodal again in autumn. In order to establish whether such seasonal changes in pattern might be at least in part controlled by endogenous temporal programs, lizards were collected at different times of the year and immediately after capture their locomotor behavior was tested in the laboratory under constant temperature (29°C) and in darkness. For some individuals tested in the laboratory the locomotor pattern previously expressed in the field was known. Seasonal differences in pattern have been unequivocally found to have an endogenous component, as most lizards in constant conditions retained the locomotor pattern shown in the field during the same season. Besides, in the bimodal lizards the freerunning period of locomotor rhythms () was significantly shorter and circadian activity time (a) longer than in the unimodal ones. Altogether the data are compatible with the idea that both the interdependent changes of and a and the changes in locomotor pattern occurring seasonally in the circadian activity rhythms of P. sicula would depend on changes in the phase relationship between mutually coupled oscillators which drive these rhythms. Correspondence to: A. Foà  相似文献   
16.
Humans show intra- and intersexual variation in second (2D) relative to fourth (4D) finger length, men having smaller 2D:4D ratio, possibly because of differential exposure to sex hormones during fetal life. The relations between 2D:4D and phenotypic traits including fitness components reported by several studies may originate from the organizational effects that sex hormones have on diverse organs and their concomitant effect on 2D:4D. Evolutionary theory posits that sexual preferences are adaptations whereby choosy individuals obtain direct or genetic indirect benefits by choosing a particular mate. Since sex hormones influence both fitness and 2D:4D, hand sexual attractiveness should depend on 2D:4D, a hypothesis tested only in one correlational study so far. We first presented hand computer images to undergraduates and found that opposite-sex hands with long 2D and 4D were considered more sexually attractive. When we experimentally manipulated hand images by increasing or decreasing 2D and/or 4D length, women preferred opposite-sex hands that had been masculinized by elongating 4D, whereas men avoided masculinized opposite-sex right hands with shortened 2D. Hence, consensus exists about which hands are attractive among different opposite-sex judges. Finger length may signal desirable sex hormone-dependent traits or genetic quality of potential mates. Psychological mechanisms mediating hand attractiveness judgments may thus reflect adaptations functioning to provide direct or indirect benefits to choosy individuals. Because the genetic mechanisms that link digit development to sex hormones may be mediated by Hox genes which are conserved in vertebrates, present results have broad implications for sexual selection studies also in nonhuman taxa.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号