全文获取类型
收费全文 | 21865篇 |
免费 | 199篇 |
国内免费 | 196篇 |
专业分类
安全科学 | 620篇 |
废物处理 | 1024篇 |
环保管理 | 2744篇 |
综合类 | 3758篇 |
基础理论 | 5280篇 |
环境理论 | 7篇 |
污染及防治 | 5970篇 |
评价与监测 | 1472篇 |
社会与环境 | 1278篇 |
灾害及防治 | 107篇 |
出版年
2022年 | 235篇 |
2021年 | 227篇 |
2020年 | 143篇 |
2019年 | 164篇 |
2018年 | 350篇 |
2017年 | 328篇 |
2016年 | 515篇 |
2015年 | 368篇 |
2014年 | 538篇 |
2013年 | 1668篇 |
2012年 | 700篇 |
2011年 | 954篇 |
2010年 | 754篇 |
2009年 | 823篇 |
2008年 | 955篇 |
2007年 | 988篇 |
2006年 | 907篇 |
2005年 | 755篇 |
2004年 | 711篇 |
2003年 | 747篇 |
2002年 | 664篇 |
2001年 | 887篇 |
2000年 | 605篇 |
1999年 | 384篇 |
1998年 | 245篇 |
1997年 | 246篇 |
1996年 | 244篇 |
1995年 | 306篇 |
1994年 | 271篇 |
1993年 | 221篇 |
1992年 | 236篇 |
1991年 | 253篇 |
1990年 | 238篇 |
1989年 | 246篇 |
1988年 | 215篇 |
1987年 | 196篇 |
1986年 | 144篇 |
1985年 | 182篇 |
1984年 | 206篇 |
1983年 | 210篇 |
1982年 | 199篇 |
1981年 | 167篇 |
1980年 | 148篇 |
1979年 | 165篇 |
1978年 | 127篇 |
1977年 | 133篇 |
1976年 | 119篇 |
1975年 | 139篇 |
1974年 | 150篇 |
1973年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Matthew Bates Paolo Bruno Mariangela Caputi Maurizio Caselli Gianluigi de Gennaro Maria Tutino 《Atmospheric environment (Oxford, England : 1994)》2008,42(24):6144-6151
The technique of thermal desorption (TD)–GC/MS was evaluated for measuring airborne, 4–6 ring polycyclic aromatic hydrocarbons (PAHs) collected onto quartz filters. TD provides a more readily automated and sensitive alternative to traditional solvent extraction, decreasing the time/cost of analysis and reducing the risk of analyte loss or sample contamination. The developed method was successfully applied to the analysis of PAH standard solutions loaded on sorbent tubes packed with quartz wool and the graphitized carbon black sorbent Carbograph2. The optimized method showed high desorption efficiency over the whole range of target PAHs with good precision, linearity and sensitivity. The proposed method was verified on an urban dust Standard Reference Material (SRM 1649a); the experimentally determined concentrations agreed with the certified ranges (95% confidence limit) for all target compounds except benzo[a]anthracene, which fell just outside the narrow certified range. The desorption efficiency and the reproducibility of the method was evaluated by analysing pieces of real sample filters sampled from urban air for a period of 24 h. The results confirmed the homogeneity of the filter and showed high recovery efficiencies for all target PAHs. 相似文献
22.
Rapid growth of clones of the red alga Chondrus crispus: applications in assays of toxic substances and in physiological studies 总被引:1,自引:0,他引:1
Growth rates of excised apical segments from three Chondrus crispus Stackhouse clones were rapid, reproducible and easily measured using simple equipment. Clonal segments exhibited a high degree of phenotypic stability, with coefficients of variation in growth rates being typically less than 5%. Sensitivity of the assay was demonstrated using 24-h pulses of the toxicants Cu2+ (10 to 150 ppb) and the molluscicide Bayluscide (100 to 500 ppb). As a further demonstration of applicability of this assay system, growth rates were measured over two consecutive 24-h photoperiods using a normally pigmented red gametophytic clone and a green colored mutant derived from it. Growth rates were highest in the first hours of the light phase for both clones, with growth of the green mutant being consistently inferior to that of the normally pigmented one. Significant changes were measured with intervals as short as 4 h using only five apical segments for each treatment. The C. crispus assay described is sensitive, relatively rapid, and statistically robust when applied to toxicant testing in seawater and to physiological studies. 相似文献
23.
24.
F. Rincón-León G. Zurera-Cosano R. Moreno-Rojas M. Amaro-López 《Environmental monitoring and assessment》1993,27(3):193-200
The importance of eating habits and the number of fish sampled in the estimation of mercury environmental contamination through biological indicators was studied. The species used were one with piscivorous habits (Anguilla anguilla) and another with omnivorous habits (Ciprinus carpio). From one original sample for each species, randomized samples were generated using the subroutine GGSRS from the mathematics library IMSL, and later the statistical significance of Pearson's correlation coefficient for the relationship between fish weight and mercury concentrations in muscle was obtained for each random sample. The results show that the use of omnivorous species such as Ciprinus carpio as a biological indicator of contamination enables us to carry out estimations with a greater degree of confidence than when piscivorous species such as Anguilla anguilla are used. 相似文献
25.
Dario Paladini Maria Giovanna Russo Antonio Tartaglione Annamaria Loffredo Pasquale Martinelli 《黑龙江环境通报》2002,22(13):1185-1187
Toriello–Carey syndrome is a rare malformative complex, described for the first time in 1988, characterized by agenesis of the corpus callosum, facial anomalies, cardiac defects and hypotonia. Relatively few neonatal cases have been reported. We describe here the first prenatal ultrasound diagnosis of the syndrome based on the detection of agenesis of the corpus callosum and spongious cardiomyopathy in a 22-week-old fetus of a couple with positive family history. The first sib of the couple was diagnosed with Toriello–Carey syndrome at 1 year of age, and had, in addition to the typical facial anomalies not detectable by ultrasound, agenesis of the corpus callosum and the same heart lesion (spongious cardiomyopathy). This report demonstrates that prenatal diagnosis of Toriello–Carey syndrome is feasible in the second trimester of pregnancy. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
26.
27.
S. Kojima S. Ohta T. Yamamoto T. Miura Y. Fujiwara K. Fujikura J. Hashimoto 《Marine Biology》2002,141(1):57-64
The nucleotide sequence of part (624 bp) of a mitochondrial gene for cytochrome oxidase I was determined for 46 escarpiid vestimentiferans collected from seven sites in the western Pacific and 49 individual specimens of Arcovestia ivanovi from two sites in the Manus Basin. Phylogenetic analysis, based on the newly obtained and previously reported sequences, indicated that escarpiids in the western Pacific can be divided into two tentative species, as we proposed in a previous report. While members of the first tentative species have been collected exclusively from a seep area at a depth of 300 m off the coast of central Japan, the members of the second species inhabit some sites at depths greater than 1,100 m, namely, seep areas in Japanese and Papua-New Guinean waters as well as hydrothermal vent fields in the Okinawa Trough and the Manus Basin. We detected no genetic structure among populations of the second tentative species. The first tentative species was more closely related to a species in the eastern Pacific, Escarpia spicata, and to a species in the Gulf of Mexico, Escarpia laminata, than to the second tentative species in the western Pacific. Sequences obtained from all arcovestiids were identical with the exception of those from three individuals, each of which included a single synonymous nucleotide substitution relative to the dominant haplotype, and no genetic differences were detected between specimens from the two sites in the Manus Basin. 相似文献
28.
29.
A significant positive correlation between the lipid content of eight fish species and their bioconcentration factor (BCF) of 1,2,4-trichlorobenzene is demonstrated. The log BCF value on a lipid basis is in good agreement with the log n-octanol/water partition coefficient. 相似文献
30.
W. F. Wood 《Marine Biology》1987,96(1):143-150
During spring and summer, 1982–1986, experiments were carried out near Marmion Reef, Western Australia. In summer, nearly 30% of the surface solar ultraviolet radiation (280 to 400 nm) penetrates offshore waters to 5 m depth. Experimental removal of the mature Ecklonia radiata kelp canopy in summer results in tissue damage, photopigment destruction, reduced growth, and low survivorship of subcanopy kelp sporophytes. These effects do not occur with canopy removal in winter. Laboratory experiments revealed that the UV component of radiation, rather than intense photosynthetically active radiation, was responsible for the inhibition of growth and photodamage. UV radiation probably affects survival of the settlement stages of E. radiata sporophytes, thus excluding them from otherwise suitable substrata in shallow waters. UV radiation is implicated in the reduction of canopy productivity in summer. 相似文献