全文获取类型
收费全文 | 347篇 |
免费 | 0篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 18篇 |
环保管理 | 33篇 |
综合类 | 155篇 |
基础理论 | 61篇 |
环境理论 | 2篇 |
污染及防治 | 59篇 |
评价与监测 | 10篇 |
社会与环境 | 10篇 |
灾害及防治 | 1篇 |
出版年
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 18篇 |
2012年 | 9篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 14篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 15篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 6篇 |
1987年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 8篇 |
1969年 | 3篇 |
1965年 | 5篇 |
1964年 | 3篇 |
1963年 | 5篇 |
1962年 | 3篇 |
1961年 | 6篇 |
1960年 | 4篇 |
1959年 | 3篇 |
1958年 | 5篇 |
1957年 | 6篇 |
1955年 | 2篇 |
1954年 | 5篇 |
1927年 | 2篇 |
排序方式: 共有355条查询结果,搜索用时 359 毫秒
71.
72.
73.
74.
75.
Archaeochronometry uses luminescence dating to reveal ages of sediments and artefacts. Uncertainties in luminescence ages are partly related to the dating procedure, which uses grain separates. This is particularly true for stone surfaces, which require an imaging method for luminescence detection. Here we present the development of a novel luminescence device with high spatial resolution as well as signal-to-noise ratio and data processing software that now allows us to determine palaeodoses and potentially the dose-rate for cut sections of rocks and artefacts. The determination of the luminescence age of single mineral grains within sections and even of selected zones within grains becomes feasible, opening up a wide field of new applications. 相似文献
76.
77.
78.
79.
80.
B.?W.?HansenEmail author T.?Marker P.?Andreassen E.?Arashkewich F.?Carlotti P.?Lindeque K.?S.?Tande M.?Wagner 《Marine Biology》2003,142(5):877-893
Two different Calanus finmarchicus (Gunnerus) cohorts originating from 60°N (Bergen) and 69°N (Tromsø) were investigated in equal environmental conditions to study their different physiological responses to the same environment. A two-plus-two-bag mesocosm study was carried out between March and July 1998, in Håkøybotn, Tromsø, in order to determine development and mortality rates of the two parallel cohorts of C. finmarchicus. For practical reasons, the cohort from Bergen was incubated 10 days earlier than the Tromsø cohort. Consequently, they were exposed to elevated food conditions as compared to the Tromsø cohort. A high initial mortality among the Bergen cohort could clearly be ascribed, by genetic discrimination, to "contamination" with C. helgolandicus. After this initial mass mortality, the mortality was constantly 0.03-0.04 dayу. In cohorts starting from naupliar stage I, there was no significant difference in development or growth, the median development time (NI-CIV) differing by only 7 days (~6%). The difference in development time can be explained to a large extent (~4 days) by temperature differences. This is substantiated with model simulations using a physiological model developed for C. finmarchicus. There was a time lag in incubation between the two cohorts, resulting in elevated temperature during incubation of the Tromsø cohort. A fraction of both cohorts differentiated sexually at stage CV, with males differentiating before females. Females from both cohorts produced eggs, but specific egg production differed significantly (P>0.001, t-test). This was supported by elevated RNA:DNA ratio in females from the Bergen cohort. Both cohorts demonstrated quite similar development and physiological growth rates and, consequently, are considered to belong to the same genetic population inhabiting the Norwegian Shelf. The study demonstrates that C. finmarchicus is capable of adaptation to changes in environment and, thereby, demonstrates a significant physiological plasticity. 相似文献