全文获取类型
收费全文 | 785篇 |
免费 | 6篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 34篇 |
环保管理 | 56篇 |
综合类 | 178篇 |
基础理论 | 161篇 |
污染及防治 | 241篇 |
评价与监测 | 58篇 |
社会与环境 | 42篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 9篇 |
2022年 | 33篇 |
2021年 | 19篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 27篇 |
2017年 | 28篇 |
2016年 | 49篇 |
2015年 | 14篇 |
2014年 | 54篇 |
2013年 | 63篇 |
2012年 | 34篇 |
2011年 | 61篇 |
2010年 | 35篇 |
2009年 | 33篇 |
2008年 | 46篇 |
2007年 | 38篇 |
2006年 | 39篇 |
2005年 | 29篇 |
2004年 | 28篇 |
2003年 | 15篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 3篇 |
1964年 | 4篇 |
1963年 | 4篇 |
1962年 | 2篇 |
1961年 | 4篇 |
1960年 | 5篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1957年 | 5篇 |
1947年 | 1篇 |
1942年 | 2篇 |
1941年 | 2篇 |
1927年 | 1篇 |
排序方式: 共有794条查询结果,搜索用时 31 毫秒
191.
Total concentrations and extractable fractionations of As and Sb were determined in soil samples from former mining sites in Scotland and Italy. Pseudo-total levels of As and Sb in the sample were between 50–17,428 mg/kg and 10–1,187 mg/kg (Scotland), and 16–691 mg/kg and 1.63–11.44 mg/kg (Italy). Between 0.001–0.63% and <0.001−8.82% of the total soil As and Sb, were extractable using, a single extraction bioavailability estimate. Data from an As-specific extraction procedure revealed that up to 60% of As was associated to amorphous Fe-Al oxyhydroxide phase in all soils. A non-specific-sequential extraction test also showed As to be strongly associated with Fe (and Al) oxyhydroxides at both locations. In the case of Sb, in addition to the crystalline Fe-oxide bound Sb the Al-silicate phase also appeared to be significant. At both sites Sb appears to be chemically more accessible than As with consistent availability despite the varied origin and host soil properties. 相似文献
192.
The swimming behaviour of laboratory-reared newly hatched cod larvae (Gadus morhua L.) was observed in a control solution of artificial seawater and in seven solutions, each with a different concentration of arginine (109 to 10-3
M). The behaviour of 20 larvae was analysed in each of the eight solutions; the individual observation time was 1 min. Individual movements were recorded on video and analyzed using a computer-assisted program. The larvae swam in straight lines (a trajectory), rested, moved and started swimming again. For the parameters analyzed, i.e., number of movements, angle between successive trajectories and straightness index, there was no significant difference between the behaviour of the larvae in the different solutions. However, for the larvae in 10-5, 10-4 and 10-3
M arginine solutions, the analyzed parameters, i.e., time active, frequency of trajectories (number of movements exceeding body length), distance swum min-1, length of individual trajectories and trajectory velocity, were all significantly lower than for the larvae in the control solution of artificial seawater and for larvae in the solutions of 10-9, 10-8, 10-7 and 10-6
M arginine. The results show that the mean distance swum by cod larvae min-1 was two to five times longer in artificial seawater without arginine and in the four lower concentrations of arginine than in the three higher concentrations. Scanning micrographs show that newly hatched (pre-feeding) cod larvae possess olfactory organs. It seems reasonalbe to assume that the observed changes in swimming behaviour are mediated by the olfactory sense and are important in the feeding strategy of cod larvae. We suggest that the observed behaviour increases the probability of the larvae localizing patches of prey organisms and remaining in the patch once they have found it. The results show that chemokinesis is a mechanism by which the spatial distribution of fish larvae will be correlated with their prey. 相似文献
193.
194.
195.
Harriet von Koskull Ph.D. Annukka Ritvanen Pirkko Ämmälä Nina Gahmberg Riitta Salonen 《黑龙江环境通报》1989,9(6):433-437
Trisomy 12 mosaicism (44 per cent) was detected prenatally in cultured amniocytes. A cordocentesis was performed to confirm the result. Only normal cells were found in the fetal blood sample. The fetus was estimated to be at a low risk of having a chromosomal abnormality and the pregnancy continued. Eight days after birth, a congenital heart defect was detected in the child. Several dysmorphic features were also evident. Further karyotyping of different tissues revealed normal blood and urinary cells but trisomic cells in the placenta (100 per cent) and in skin fibroblasts (25 per cent). The child died at 5 weeks of age. In this case, the fetal blood sample failed to reveal the real chromosome constitution of the fetus. 相似文献
196.
利用景观信息分析和预测环境变化:扩展的基线观点—坦桑尼亚两?… 总被引:1,自引:0,他引:1
197.
Khanam Tahamina Rahman Abul Mola-Yudego Blas Pykäläinen Jouni 《Mitigation and Adaptation Strategies for Global Change》2020,25(4):733-734
Mitigation and Adaptation Strategies for Global Change - This paper was published on March 2017, Volume 22, Issue 3, 469–483pp, titled “Identification of structural breaks in the forest... 相似文献
198.
Gabriel L. Castiglioni Jorge Cuellar Raúl Rodrigo Jorge A. V. Costa Ranulfo Monte-Alegre 《Journal of Polymers and the Environment》2016,24(3):264-273
Macroporous poly(styrene-co-divinylbenzene) microparticles, with three different structural characteristics, have been synthesized and used as supports in the immobilization of lipase from Burkholderia cepacia. The best immobilization yield was found upon using microparticles with 35 % of divinylbenzene and the immobilized lipase on this type of particles was used as a catalyst to obtain biodiesel from soybean oil and ethanol. From the experimental results of the transesterification reaction, an empirical model quantitatively relating the temperature, the concentration of the enzyme and the transesterification yield was obtained. Statistical analysis of this model indicated that within the range of values of the variables studied (35–47 °C and 231–788 U/mg respectively) only the enzyme concentration exerted a significant influence on the reaction yield. Additionally, the good fit of a Michaelis–Menten-type model to the experimental results suggests that the limiting step of the reaction was the formation of the enzyme-substrate complex. 相似文献
199.
John E. Mathieu 《组织行为杂志》2016,37(8):1132-1141
Theory is essential to everything that we do as people studying and practicing industrial/organizational psychology and organizational behavior. But, I think that our field has lost its way recently and become enamored by shiny objects and interesting puzzles. Advancing management theory seems to have become an end state in and of itself. We seemed to be far more concerned with the entertainment value of theories than we are with their scientific rigor or real‐world value. Top journals in our field are mandating that all articles must make a theoretical contribution, and theoretical contributions are being gauged primarily in terms of how innovative, counter‐intuitive, surprising, and interesting they may be. I advocate for a more balanced approach, and in particular, for greater use of abductive inference. I argue that if you start with a real‐world challenge and draw from existing theory, and then develop new theory to understand and change things, you are also making a theoretical contribution. Whether or not we are guided by theory is not really at issue—at issue is how well developed are our theories, how accurate are they, and do they help us to improve organizational life for everyone involved? 相似文献
200.