全文获取类型
收费全文 | 30350篇 |
免费 | 347篇 |
国内免费 | 475篇 |
专业分类
安全科学 | 957篇 |
废物处理 | 1440篇 |
环保管理 | 3676篇 |
综合类 | 5089篇 |
基础理论 | 7962篇 |
环境理论 | 18篇 |
污染及防治 | 8007篇 |
评价与监测 | 2071篇 |
社会与环境 | 1773篇 |
灾害及防治 | 179篇 |
出版年
2023年 | 135篇 |
2022年 | 301篇 |
2021年 | 318篇 |
2020年 | 240篇 |
2019年 | 286篇 |
2018年 | 478篇 |
2017年 | 478篇 |
2016年 | 744篇 |
2015年 | 568篇 |
2014年 | 887篇 |
2013年 | 2419篇 |
2012年 | 1067篇 |
2011年 | 1437篇 |
2010年 | 1171篇 |
2009年 | 1197篇 |
2008年 | 1438篇 |
2007年 | 1487篇 |
2006年 | 1266篇 |
2005年 | 1097篇 |
2004年 | 985篇 |
2003年 | 1076篇 |
2002年 | 952篇 |
2001年 | 1238篇 |
2000年 | 863篇 |
1999年 | 520篇 |
1998年 | 349篇 |
1997年 | 359篇 |
1996年 | 351篇 |
1995年 | 423篇 |
1994年 | 447篇 |
1993年 | 352篇 |
1992年 | 374篇 |
1991年 | 353篇 |
1990年 | 386篇 |
1989年 | 343篇 |
1988年 | 297篇 |
1987年 | 278篇 |
1986年 | 223篇 |
1985年 | 248篇 |
1984年 | 265篇 |
1983年 | 256篇 |
1982年 | 241篇 |
1981年 | 222篇 |
1980年 | 175篇 |
1979年 | 194篇 |
1978年 | 176篇 |
1975年 | 140篇 |
1974年 | 117篇 |
1972年 | 130篇 |
1971年 | 131篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
P. A. Zadubrovskiy I. V. Zadubrovskaya M. A. Potapov O. F. Potapova V. I. Evsikov 《Russian Journal of Ecology》2016,47(1):82-87
Demographic structure and its seasonal dynamics have been studied in colonies of narrow-skulled voles (Lasiopodomys gregalis Pall.) in Northern Kulunda. Three types of colonies have been distinguished: (I) true colonies (large, complex families), (II) simple families (nuclear or incomplete), and (III) all-male colonies. Changes in their sex, age, and functional composition (based on animal migration activity) during the breeding season have been analyzed. 相似文献
972.
Damon M. Hall Gerardo R. Camilo Rebecca K. Tonietto Jeff Ollerton Karin Ahrné Mike Arduser John S. Ascher Katherine C. R. Baldock Robert Fowler Gordon Frankie Dave Goulson Bengt Gunnarsson Mick E. Hanley Janet I. Jackson Gail Langellotto David Lowenstein Emily S. Minor Stacy M. Philpott Simon G. Potts Muzafar H. Sirohi Edward M. Spevak Graham N. Stone Caragh G. Threlfall 《Conservation biology》2017,31(1):24-29
Research on urban insect pollinators is changing views on the biological value and ecological importance of cities. The abundance and diversity of native bee species in urban landscapes that are absent in nearby rural lands evidence the biological value and ecological importance of cities and have implications for biodiversity conservation. Lagging behind this revised image of the city are urban conservation programs that historically have invested in education and outreach rather than programs designed to achieve high‐priority species conservation results. We synthesized research on urban bee species diversity and abundance to determine how urban conservation could be repositioned to better align with new views on the ecological importance of urban landscapes. Due to insect pollinators’ relatively small functional requirements—habitat range, life cycle, and nesting behavior—relative to larger mammals, we argue that pollinators put high‐priority and high‐impact urban conservation within reach. In a rapidly urbanizing world, transforming how environmental managers view the city can improve citizen engagement and contribute to the development of more sustainable urbanization. 相似文献
973.
Mário Paz Luísa Correia-Sá Carla B. Vidal Helena Becker Elisane Longhinotti 《Journal of environmental science and health. Part. B》2017,52(1):48-58
The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was applied to the extraction of 14 organochlorine pesticides (OCPs) residues from commercial fruit pulps available in supermarkets in Fortaleza, Northeastern Brazil. The analyses were carried out by gas chromatography (GC), coupled to an electron-capture detector (ECD), and were confirmed by GC-tandem mass spectrometry (MS). The parameters of the analytical method, such as accuracy, precision, linear range, limits of detection and quantification, were determined for each pesticide. The results showed good linearity (R2 ≥ 0.9916) and the overall average recoveries were considered satisfactory obtaining values between 69 and 110%, RSD of 2–15 %, except for hexachlorobenzene (HCB) in açai, acerola and guava pulp samples. The OCPs were detected in guava (α–HCH; lindane) and soursop (α, β–HCH isomers) samples. The QuEChERS method and GC–ECD were successfully used to analyze OCPs in commercially available Brazilian fruit pulps and can be applied in routine analytical laboratories. 相似文献
974.
W. M. Choi C. L. Lam W. Y. Mo M. H. Wong 《Environmental science and pollution research international》2016,23(8):7186-7194
The fast growing of global aquaculture industry accompanied with increasing pressure on the supply and price of traditional feed materials (e.g., fish meal and soy bean meal). This circumstance has urged the need to search alternative sources of feed stuff. Food waste was used as feed stuff in rearing fish which possess substantial protein and lipid. Grass carp are major species reared in Hong Kong with lower nutritional requirements; it is also an ideal species for investigating the feasibility of using food waste as fish feeds for local aquaculture industry. The growth and immunity, reflected by total protein, total immunologlobulin (IgI), and nitroblue tetrazolium (NBT) activity of grass carp blood, were depressed when feeding with food waste feeds without enzymes. However, the supplementation of bromelain and papain in fish feed enhanced the efficient use of food waste by grass carp, which in turn improved the fish immunity. The present results indicated that the addition of those enzymes could enhance the feed utilization by fish and hematological parameters of grass carp, and the improvement on growth and immunity superior to the control (commercial feed) was observed with the addition of bromelain and papain supplement. Addition of 1 and 2 % mixture of bromelain and papain could significantly enhance the lipid utilization in grass carp. 相似文献
975.
A. V. M. Subba Rao Arun K. Shanker V. U. M. Rao V. Narsimha Rao A. K. Singh Pragyan Kumari C. B. Singh Praveen Kumar Verma P. Vijaya Kumar B. Bapuji Rao Rajkumar Dhakar M. A. Sarath Chandran C. V. Naidu J. L. Chaudhary Ch. Srinivasa Rao B. Venkateshwarlu 《Environmental Modeling and Assessment》2016,21(1):17-30
976.
M. W. Gitari S. A. Akinyemi L. Ramugondo M. Matidza S. E. Mhlongo 《Environmental geochemistry and health》2018,40(6):2421-2439
The economic benefits of mining industry have often overshadowed the serious challenges posed to the environments through huge volume of tailings generated and disposed in tailings dumps. Some of these challenges include the surface and groundwater contamination, dust, and inability to utilize the land for developmental purposes. The abandoned copper mine tailings in Musina (Limpopo province, South Africa) was investigated for particle size distribution, mineralogy, physicochemical properties using arrays of granulometric, X-ray diffraction, and X-ray fluorescence analyses. A modified Community Bureau of Reference (BCR) sequential chemical extraction method followed by inductively coupled plasma mass spectrometry/atomic emission spectrometry (ICP-MS/AES) technique was employed to assess bioavailability of metals. Principal component analysis was performed on the sequential extraction data to reveal different loadings and mobilities of metals in samples collected at various depths. The pH ranged between 7.5 and 8.5 (average?≈?8.0) indicating alkaline medium. Samples composed mostly of poorly grated sands (i.e. 50% fine sand) with an average permeability of about 387.6 m/s. Samples have SiO2/Al2O3 and Na2O/(Al2O3?+?SiO2) ratios and low plastic index (i.e. PI?≈?2.79) suggesting non-plastic and very low dry strength. Major minerals were comprised of quartz, epidote, and chlorite while the order of relative abundance of minerals in minor quantities is plagioclase?>?muscovite?>?hornblende?>?calcite?>?haematite. The largest percentage of elements such as As, Cd and Cr was strongly bound to less extractable fractions. Results showed high concentration and easily extractable Cu in the Musina Copper Mine tailings, which indicates bioavailability and poses environmental risk and potential health risk of human exposure. Principal component analysis revealed Fe-oxide/hydroxides, carbonate and clay components, and copper ore process are controlling the elements distribution. 相似文献
977.
978.
E. S. Zakharov V. M. Safronov L. P. Koryakina N. N. Smetanin 《Russian Journal of Ecology》2016,47(4):392-398
The population of foxes in the central regions of Yakutia has grown by a factor of four to five during the period from 2000 to 2011–2012, following an increase in the abundance of voles from the genus Microtus. A total of 130 carcasses of foxes taken in 2007–2012 have been examined. Age- and sex-related variation in morphological features has been described. The demographic structure of the population has been studied by estimating animal age from annual layers in the recording structures. Changes in female fertility and involvement in reproduction depending on age and feeding conditions have been analyzed. Changes in the composition of fox diet caused by long-term population depression in the mountain hare and their effect on the dynamics of fox abundance have been revealed. Age- and sex-related characteristics of the condition factor in foxes and sex-related differences in their dietary preferences have been demonstrated. 相似文献
979.
M. H. Alzawqari A. A. Al-Baddany H. H. Al-Baadani I. A. Alhidary Rifat Ullah Khan G. M. Aqil A. Abdurab 《Environmental science and pollution research international》2016,23(17):17077-17082
The current experiment was conducted to evaluate the effects of feeding dried sweet orange peel (SOP) and lemon grass leaves (LGL) as feed additives on broiler growth performance, serum metabolites, and antioxidant status. A total of 192-day-old (Ross 308) broiler chickens were distributed randomly into 4 dietary treatments with 4 replicates per each treatment. The dietary treatments included a control diet without any feed additive (T1), a diet containing 0.8 % SOP (T2), a diet containing 0.8 % LGL (T3), and a diet containing combination of 0.4 % SOP?+?0.4 % LGL (T4) was fed during the growth period from 22 to 42 days. Feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), carcass traits, serum components, and antioxidant status were measured. At the end of the experimental period, the results indicated that supplementation of SOP and LGL alone or in combination did not significantly (P?>?0.05) affect BWG, FI, FCR, and carcass characteristics in broiler chickens. Serum total protein was increased significantly (P?<?0.05) in T3 and T4 compared to the other treatments. Also, serum globulin increased significantly (P?<?0.05) in the treated groups. Serum glucose, low density lipoprotein, triglyceride, and very low density lipoprotein decreased significantly (P?<?0.05) in the treatment groups, while cholesterol and high-density lipoprotein decreased in T2 compared to the other groups. Significantly (P?<?0.05) higher total antioxidant status was observed in T2 compared to the other treatments. In conclusion, these results indicate that SOP, LGL, and their combination may positively modify some serum components and the antioxidant status without any beneficial effect on growth performance and carcass traits in broiler chickens. 相似文献
980.
M. J. Bebianno S. Sroda T. Gomes P. Chan E. Bonnafe H. Budzinski F. Geret 《Environmental science and pollution research international》2016,23(6):5046-5055
The increase use of pharmaceutical compounds in veterinary practice and human population results in the ubiquitous presence of these compounds in aquatic ecosystems. Because pharmaceuticals are highly bioactive, there is concern about their toxicological effects in aquatic organisms. Therefore, the aim of this study was to assess the effects of an effluent from a psychiatric hospital (containing a complex mixture of 25 pharmaceutical compounds from eleven therapeutic classes) on the freshwater clam Corbicula fluminea using a proteomic approach. The exposure of C. fluminea to this complex effluent containing anxiolytics, analgesics, lipid regulators, beta blockers, antidepressants, antiepileptics, antihistamines, antihypertensives, antiplatelets and antiarrhythmics induced protein changes after 1 day of exposure in clam gills and digestive gland more evident in the digestive gland. These changes included increase in the abundance of proteins associated with structural (actin and tubulin), cellular functions (calreticulin, proliferating cell nuclear antigen (PCNA), T complex protein 1 (TCP1)) and metabolism (aldehyde dehydrogenase (ALDH), alcohol dehydrogenase, 6 phosphogluconate dehydrogenase). Results from this study indicate that calreticulin, PCNA, ALDH and alcohol dehydrogenase in the digestive gland and T complex protein 1 (TCP1)) and 6 phosphogluconate dehydrogenase in the gills represent useful biomarkers for the ecotoxicological characterization of psychiatric hospital effluents in this species. 相似文献