全文获取类型
收费全文 | 32246篇 |
免费 | 315篇 |
国内免费 | 267篇 |
专业分类
安全科学 | 837篇 |
废物处理 | 1375篇 |
环保管理 | 4028篇 |
综合类 | 6097篇 |
基础理论 | 8485篇 |
环境理论 | 14篇 |
污染及防治 | 8157篇 |
评价与监测 | 2142篇 |
社会与环境 | 1497篇 |
灾害及防治 | 196篇 |
出版年
2022年 | 254篇 |
2021年 | 231篇 |
2019年 | 212篇 |
2018年 | 417篇 |
2017年 | 424篇 |
2016年 | 660篇 |
2015年 | 499篇 |
2014年 | 796篇 |
2013年 | 2429篇 |
2012年 | 963篇 |
2011年 | 1304篇 |
2010年 | 1064篇 |
2009年 | 1093篇 |
2008年 | 1287篇 |
2007年 | 1325篇 |
2006年 | 1206篇 |
2005年 | 1052篇 |
2004年 | 1020篇 |
2003年 | 999篇 |
2002年 | 939篇 |
2001年 | 1220篇 |
2000年 | 861篇 |
1999年 | 533篇 |
1998年 | 382篇 |
1997年 | 412篇 |
1996年 | 412篇 |
1995年 | 473篇 |
1994年 | 436篇 |
1993年 | 380篇 |
1992年 | 398篇 |
1991年 | 405篇 |
1990年 | 426篇 |
1989年 | 385篇 |
1988年 | 370篇 |
1987年 | 315篇 |
1986年 | 318篇 |
1985年 | 299篇 |
1984年 | 344篇 |
1983年 | 308篇 |
1982年 | 355篇 |
1981年 | 312篇 |
1980年 | 247篇 |
1979年 | 279篇 |
1978年 | 257篇 |
1977年 | 219篇 |
1975年 | 210篇 |
1974年 | 235篇 |
1973年 | 221篇 |
1972年 | 221篇 |
1971年 | 213篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Lasun T. Ogundele Oyediran K. Owoade Felix S. Olise Philip K. Hopke 《Environmental monitoring and assessment》2016,188(10):574
To identify the potential sources responsible for the particulate matter emission from secondary iron and steel smelting factory environment, PM2.5 and PM2.5?10 particles were collected using the low-volume air samplers twice a week for a year. The samples were analyzed for the elemental and black carbon content using x-ray fluorescence spectrometer and optical transmissometer, respectively. The average mass concentrations were 216.26, 151.68, and 138. 62 μg/m3 for PM2.5 and 331.36, 190.01, and 184.60 μg/m3 for PM2.5?10 for the production, outside M1 and outside M2 sites, respectively. The same size resolved data set were used as input for the positive matrix factorization (PMF), principal component factor analysis (PCFA), and Unmix (UNMIX) receptor modeling in order to identify the possible sources of particulate matter and their contribution. The PMF resolved four sources with their respective contributions were metal processing (33 %), e-waste (33 %), diesel emission (22 %) and soil (12 %) for PM2.5, and coking (50 %), soil (29 %), metal processing (16 %) and diesel combustion (5 %) for PM2.5?10. PCFA identified soil, metal processing, Pb source, and diesel combustion contributing 45, 41, 9, and 5 %, respectively to PM2.5 while metal processing, soil, coal combustion and open burning contributed 43, 38, 12, and 7 %, respectively to the PM2.5?10. Also, UNMIX identified metal processing, soil, and diesel emission with 43, 42 and 15 % contributions, respectively for the fine fraction, and metal processing (71 %), soil (21 %) and unidentified source (1 %) for the coarse fraction. The study concluded that metal processing and e-waste are the major sources contributing to the fine fraction while coking and soil contributed to the coarse fraction within the factory environment. The application of PMF, PCFA and UNMIX receptor models improved the source identification and apportionment of particulate matter drive in the study area. 相似文献
993.
Adaptations in infrastructure may be necessitated by changes in temperature and precipitation patterns to avoid losses and maintain expected levels of service. A roster of adaptation strategies has emerged in the climate change literature, especially with regard to timing: anticipatory, concurrent, or reactive. Significant progress has been made in studying climate change adaptation decision making that incorporates uncertainty, but less work has examined how strategies interact with existing infrastructure characteristics to influence adaptability. We use a virtual testbed of highway drainage crossings configured with a selection of actual culvert emplacements in Colorado, USA, to examine the effect of adaptation strategy and culvert characteristics on cost efficiency and service level under varying rates of climate change. A meta-model approach with multinomial regression is used to compare the value of better climate change predictions with better knowledge of existing crossing characteristics. We find that, for a distributed system of infrastructural units like culverts, knowing more about existing characteristics can improve the efficacy of adaptation strategies more than better projections of climate change. Transportation departments choosing climate adaptation strategies often lack detailed data on culverts, and gathering that data could improve the efficiency of adaptation despite climate uncertainty. 相似文献
994.
I. V. Seryodkin V. A. Zaitsev Yu. K. Petrunenko D. A. Maksimova D. G. Miquelle 《Russian Journal of Ecology》2017,48(4):372-376
The role of the Siberian musk deer in the diets of the Amur tiger, brown bear, and Asian black bear has been studied in the Sikhote-Alin State Biosphere Reserve in 1992 to 2016. Information has been collected from 763 tiger feeding sites, and the contents of tiger feces have been analyzed. Radiotelemetry has been used to evaluate tiger–musk deer relationships. The musk deer accounted for 0.26% of all animal species found to be eaten by the tiger. Musk deer remains in feces of the tiger, brown bear, and Asian black bear occurred with frequencies of 1.3, 0.2, and 0.3%, respectively. A case of musk deer avoiding the presence of brown bear is described. 相似文献
995.
996.
997.
Estelle Lefrançois Laure Apothéloz-Perret-Gentil Philippe Blancher Samuel Botreau Cécile Chardon Laura Crepin Tristan Cordier Arielle Cordonier Isabelle Domaizon Benoit J. D. Ferrari Julie Guéguen Jean-Christophe Hustache Louis Jacas Stephan Jacquet Sonia Lacroix Anne-Laurence Mazenq Alina Pawlowska Pascal Perney Jan Pawlowski Frédéric Rimet Jean-François Rubin Dominique Trevisan Régis Vivien Agnès Bouchez 《Environmental science and pollution research international》2018,25(34):33858-33866
The effectiveness of environmental protection measures is based on the early identification and diagnosis of anthropogenic pressures. Similarly, restoration actions require precise monitoring of changes in the ecological quality of ecosystems, in order to highlight their effectiveness. Monitoring the ecological quality relies on bioindicators, which are organisms revealing the pressures exerted on the environment through the composition of their communities. Their implementation, based on the morphological identification of species, is expensive because it requires time and experts in taxonomy. Recent genomic tools should provide access to reliable and high-throughput environmental monitoring by directly inferring the composition of bioindicators’ communities from their DNA (metabarcoding). The French-Swiss program SYNAQUA (INTERREG France-Switzerland 2017–2019) proposes to use and validate the tools of environmental genomic for biomonitoring and aims ultimately at their implementation in the regulatory bio-surveillance. SYNAQUA will test the metabarcoding approach focusing on two bioindicators, diatoms, and aquatic oligochaetes, which are used in freshwater biomonitoring in France and Switzerland. To go towards the renewal of current biomonitoring practices, SYNAQUA will (1) bring together different actors: scientists, environmental managers, consulting firms, and biotechnological companies, (2) apply this approach on a large scale to demonstrate its relevance, (3) propose robust and reliable tools, and (4) raise public awareness and train the various actors likely to use these new tools. Biomonitoring approaches based on such environmental genomic tools should address the European need for reliable, higher-throughput monitoring to improve the protection of aquatic environments under multiple pressures, guide their restoration, and follow their evolution. 相似文献
998.
999.
1000.
M. Stefanidou E. Anastasiou K. Georgiadis Filikas 《Waste management (New York, N.Y.)》2014,34(12):2595-2602
The increasing awareness of the society about safe guarding heritage buildings and at the same time protecting the environment promotes strategies of combining principles of restoration with environmentally friendly materials and techniques. Along these lines, an experimental program was carried out in order to investigate the possibility of producing repair, lime-based mortars used in historic buildings incorporating secondary materials. The alternative material tested was recycled fine aggregates originating from mixed construction and demolition waste. Extensive tests on the raw materials have been performed and mortar mixtures were produced using different binding systems with natural, standard and recycled sand in order to compare their mechanical, physical and microstructure properties. The study reveals the improved behavior of lime mortars, even at early ages, due to the reaction of lime with the Al and Si constituents of the fine recycled sand. The role of the recycled sand was more beneficial in lime mortars rather than the lime–pozzolan or lime–pozzolan–cement mortars as a decrease in their performance was recorded in the latter cases due to the mortars’ structure. 相似文献