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151.
Jolien Schure Verina Ingram Julius Chupezi Tieguhong Cleto Ndikumagenge 《Resources Policy》2011,36(4):363-371
This paper examines the institutional framework of artisanal mining in the forests of the Sangha Tri-National Landscape (TNS) in the Congo Basin. Artisanal miners in Cameroon and the Central African Republic (CAR) commonly make sacrifices to their god of diamonds, to improve fortunes. This study looks into ‘the other forces’; institutions that play a role in shaping the sector and its outcomes. These institutions comprise formal and informal institutions at a local, national, regional and international level. Although artisanal miners in TNS benefit by gaining cash income, this activity also carries risks as income is highly disparate and environmental impacts in this priority forest conservation area are expected to increase due to the growing competition over land use. It was concluded from a literature review, interviews and site visits that informal arrangements dominate the sector, especially in Cameroon, leading to poor relations between officials and miners and meaning that miners have few rights and no voice. The current institutional setup is inadequate to deal with current and anticipated social and environmental issues. Future interventions need to take into account the existing (local) types of organization, vulnerable groups, the interests of multiple actors and the fact that most miners are experienced but combine mining with other activities, such as agriculture, fishing and harvesting forest products. African initiatives concerning ASM offer opportunities to Cameroon and CAR to collaborate with other countries to combat similar issues. A regional integrated approach of both the forest and mining sector would be especially relevant for trans-boundary agreements, such as concerning the TNS, to reinforce positive outcomes for the landscape and the area's population. 相似文献
152.
Ben T. Hirsch 《Behavioral ecology and sociobiology》2011,65(4):581-591
The location of an animal within a social group has important effects on feeding success. When animals consume quickly eaten
food items, individuals located at the front edge of a group typically have greater foraging success. When groups feed at
large clumped resources, dominant individuals can often monopolize the resource, leading to higher feeding success in the
center of the group. In order to test these predictions, behavioral data relating foraging success to within-group spatial
position were recorded from two habituated groups of ring-tailed coatis (Nasua nasua) in Iguazu, Argentina. Foraging success did not fit expected patterns. When feeding on small ground litter invertebrates,
coatis had the same foraging success at all spatial positions. This pattern likely resulted from an abundance of invertebrates
in the ground litter. When feeding on fruit, individuals in the front of the group had greater feeding success, which was
driven by the relatively quick depletion of fruit trees. Dominant juveniles were often located in the front of the group which
led to increased access to food. This resulted in higher feeding success on fruits but simultaneously increased their risk
of predation. Although groups typically became more elongated and traveled faster when feeding on fruit, it did not appear
that the coatis were drastically changing their spacing strategies when switching between the two food types. Paradoxically,
spatial position preferences during invertebrate foraging appeared to be driven by fruit trees. Because fruit trees were encountered
so frequently, juveniles ranging at the front edge of the group during invertebrate foraging were the first to arrive at fruit
trees and thus had higher foraging success. This study demonstrates the importance of how food patch size and depletion rate
affect the spatial preferences of individuals. 相似文献
153.
PROBLEM: In many jurisdictions, driver education (DE) graduates, compared to non-graduates, are granted a time-discount that allows them to drive unsupervised several months earlier, despite little evidence of a safety benefit and consistent evidence of increased crash risk. Confounding factors may be threatening the validity of DE evaluations. A theoretical framework called the "licensing process" (LP) is proposed to identify and explore potential confounding factors in DE evaluations. METHOD: Prospective study data on a cohort of 1804 novice drivers 16 to 19 years of age of both sexes are analyzed in relation to the LP framework. These data derive from two sources that were linked together: an extensive questionnaire on learning methods, risk-taking, and lifestyles, and government records on exam performance, violations, and crashes. RESULTS: Violation and crash records are not associated with DE attendance. DE attendance is associated with younger ages, greater financial support from family, and fewer hours of supervised driving practice with a learner's permit. For both sexes, more hours of supervised driving practice with a learner's permit is associated with increased crash risk. Most participants, particularly males under 19 years of age, attended DE partly or entirely to save time or money; these motivations are associated with higher violation and crash rates. DISCUSSION: DE evaluations need to identify and control for potential confounding factors. Research is needed to understand the associations between increased crash risk and potential confounding factors like motivation to attend DE and hours of supervised driving practice. 相似文献