全文获取类型
收费全文 | 606篇 |
免费 | 16篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 31篇 |
环保管理 | 85篇 |
综合类 | 138篇 |
基础理论 | 109篇 |
环境理论 | 1篇 |
污染及防治 | 164篇 |
评价与监测 | 43篇 |
社会与环境 | 26篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 12篇 |
2022年 | 21篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 24篇 |
2016年 | 34篇 |
2015年 | 22篇 |
2014年 | 24篇 |
2013年 | 37篇 |
2012年 | 47篇 |
2011年 | 32篇 |
2010年 | 18篇 |
2009年 | 31篇 |
2008年 | 31篇 |
2007年 | 34篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 15篇 |
2003年 | 21篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 10篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1983年 | 3篇 |
1964年 | 2篇 |
1959年 | 2篇 |
1957年 | 2篇 |
1925年 | 2篇 |
1924年 | 2篇 |
1923年 | 2篇 |
1921年 | 3篇 |
1918年 | 2篇 |
1917年 | 1篇 |
1914年 | 1篇 |
排序方式: 共有629条查询结果,搜索用时 140 毫秒
401.
An absence of aggression between non-nestmates in the bull ant <Emphasis Type="Italic">Myrmecia nigriceps</Emphasis> 总被引:2,自引:0,他引:2
van Wilgenburg E Dang S Forti AL Koumoundouros TJ Ly A Elgar MA 《Die Naturwissenschaften》2007,94(9):787-790
The ability of social insects to discriminate against non-nestmates is vital for maintaining colony integrity, and in most
social insect species, individuals act aggressively towards non-nestmates that intrude into their nest. Our experimental field
data revealed that intra-colony aggression in the primitive bulldog ant Myrmecia nigriceps is negligible; our series of bioassays revealed no significant difference in the occurrence of aggression in trials involving
workers from the same, a close (less than 300 m) or a far (more than 1.5 km) nest. Further, non-nestmate intruders were able
to enter the nest in 60% of our trials; a similar level was observed in trials involving nestmates. These results suggest
that workers of M. nigriceps are either unable to recognize alien conspecifics or that the costs of ignoring workers from foreign colonies are sufficiently
low to favor low levels of inter-colony aggression in this species. 相似文献
402.
Katherine?P.?Gill Ellen?van?Wilgenburg Peter?Taylor Mark?A.?ElgarEmail author 《Die Naturwissenschaften》2012,99(3):245-248
Social insect colonies exhibit highly coordinated responses to ecological challenges by acquiring information that is disseminated
throughout the colony. Some responses are coordinated directly from the signals produced by individuals that acquired the
information. Other responses may require information to be transferred indirectly through a third party, thereby requiring
colony-wide retention of information. Social insects use colony signature odours to distinguish between nestmates and non-nestmates,
and the level of aggression between non-nestmates typically varies according to the distance between colonies and thus their
history of interactions. Such coordinated, colony-specific responses may require information about particular odours to be
disseminated and retained across the colony. Our field experiments with weaver ants reveal colony-wide, indirect acquisition
and retention of the signature odours of a different colony with which they had experienced aggression. These data highlight
the significance of interaction history and suggest the presence of a collective memory. 相似文献
403.
Alain?DejeanEmail author James?M.?Carpenter Bruno?Corbara Pamela?Wright Olivier?Roux Louis?M.?LaPierre 《Die Naturwissenschaften》2012,99(4):265-273
Here we show that trying to rob prey (cleptobiosis) from a highly specialized predatory ant species is risky. To capture prey,
Allomerus decemarticulatus workers build gallery-shaped traps on the stems of their associated myrmecophyte, Hirtella physophora. We wondered whether the frequent presence of immobilized prey on the trap attracted flying cleptoparasites. Nine social
wasp species nest in the H. physophora foliage; of the six species studied, only Angiopolybia pallens rob prey from Allomerus colonies. For those H. physophora not sheltering wasps, we noted cleptobiosis by stingless bees (Trigona), social wasps (A. pallens and five Agelaia species), assassin bugs (Reduviidae), and flies. A relationship between the size of the robbers and their rate of capture
by ambushing Allomerus workers was established for social wasps; small wasps were easily captured, while the largest never were. Reduviids, which
are slow to extract their rostrum from prey, were always captured, while Trigona and flies often escaped. The balance sheet for the ants was positive vis-à-vis the reduviids and four out of the six social
wasp species. For the latter, wasps began by cutting up parts of the prey’s abdomen and were captured (or abandoned the prey)
before the entire abdomen was retrieved so that the total weight of the captured wasps exceeded that of the prey abdomens.
For A. pallens, we show that the number of individuals captured during attempts at cleptobiosis increases with the size of the Allomerus’ prey. 相似文献
404.
405.
Bruno Takahashi Guy Edwards J. Timmons Roberts Ran Duan 《Environmental Communication: A Journal of Nature and Culture》2015,9(2):228-247
The engagement of environmental non-governmental groups in collaborative communication efforts and decision-making about climate change remains a significant challenge. In Latin America, the website Intercambio Climático was set up to attempt to play a breakthrough role in the region's discussion of climate change. This case study focuses on the development, accomplishments, and challenges of this unique online communication initiative among non-governmental organizations working in climate change issues in Latin America with a US-based partner, as a vehicle to achieve their goals. We used secondary data and in-depth interviews to examine this platform's role in disseminating information and influencing decision-making. The results suggest that generally the participants perceive the website positively, but there are also problematic aspects of the collaboration that are not fully recognized by the members, which prevents a more functional and effective communication strategy. 相似文献
406.
407.
408.
Objective: The purpose of this study was to use the detailed medical injury information in the Crash Injury Research and Engineering Network (CIREN) to evaluate patterns of rib fractures in real-world crash occupants in both belted and unbelted restraint conditions. Fracture patterns binned into rib regional levels were examined to determine normative trends associated with belt use and other possible contributing factors.Methods: Front row adult occupants with Abbreviated Injury Scale (AIS) 3+ rib fractures, in frontal crashes with a deployed frontal airbag, were selected from the CIREN database. The circumferential location of each rib fracture (with respect to the sternum) was documented using a previously published method (Ritchie et al. 2006) and digital computed tomography scans. Fracture patterns for different crash and occupant parameters (restraint use, involved physical component, occupant kinematics, crash principal direction of force, and occupant age) were compared qualitatively and quantitatively.Results: There were 158 belted and 44 unbelted occupants included in this study. For belted occupants, fractures were mainly located near the path of the shoulder belt, with the majority of fractures occurring on the inboard (with respect to the vehicle) side of the thorax. For unbelted occupants, fractures were approximately symmetric and distributed across both sides of the thorax. There were negligible differences in fracture patterns between occupants with frontal (0°) and near side (330° to 350° for drivers; 10° to 30° for passengers) crash principal directions of force but substantial differences between groups when occupant kinematics (and contacts within the vehicle) were considered. Age also affected fracture pattern, with fractures tending to occur more anteriorly in older occupants and more laterally in younger occupants (both belted and unbelted).Conclusions: Results of this study confirmed with real-world data that rib fracture patterns in unbelted occupants were more distributed and symmetric across the thorax compared to belted occupants in crashes with a deployed frontal airbag. Other factors, such as occupant kinematics and occupant age, also produced differing patterns of fractures. Normative data on rib fracture patterns in real-world occupants can contribute to understanding injury mechanisms and the role of different causation factors, which can ultimately help prevent fractures and improve vehicle safety. 相似文献
409.