全文获取类型
收费全文 | 6389篇 |
免费 | 112篇 |
国内免费 | 94篇 |
专业分类
安全科学 | 240篇 |
废物处理 | 295篇 |
环保管理 | 1498篇 |
综合类 | 777篇 |
基础理论 | 1401篇 |
环境理论 | 6篇 |
污染及防治 | 1623篇 |
评价与监测 | 420篇 |
社会与环境 | 273篇 |
灾害及防治 | 62篇 |
出版年
2023年 | 39篇 |
2022年 | 29篇 |
2021年 | 75篇 |
2020年 | 48篇 |
2019年 | 84篇 |
2018年 | 113篇 |
2017年 | 131篇 |
2016年 | 167篇 |
2015年 | 175篇 |
2014年 | 177篇 |
2013年 | 618篇 |
2012年 | 251篇 |
2011年 | 351篇 |
2010年 | 284篇 |
2009年 | 283篇 |
2008年 | 341篇 |
2007年 | 355篇 |
2006年 | 310篇 |
2005年 | 208篇 |
2004年 | 258篇 |
2003年 | 230篇 |
2002年 | 227篇 |
2001年 | 145篇 |
2000年 | 134篇 |
1999年 | 110篇 |
1998年 | 80篇 |
1997年 | 89篇 |
1996年 | 88篇 |
1995年 | 102篇 |
1994年 | 81篇 |
1993年 | 71篇 |
1992年 | 87篇 |
1991年 | 67篇 |
1990年 | 62篇 |
1989年 | 60篇 |
1988年 | 39篇 |
1987年 | 42篇 |
1986年 | 46篇 |
1985年 | 45篇 |
1984年 | 49篇 |
1983年 | 52篇 |
1982年 | 48篇 |
1981年 | 64篇 |
1980年 | 47篇 |
1979年 | 31篇 |
1978年 | 27篇 |
1977年 | 19篇 |
1975年 | 17篇 |
1971年 | 15篇 |
1970年 | 16篇 |
排序方式: 共有6595条查询结果,搜索用时 15 毫秒
1.
Rudra P. Pradhan Mahendhiran S. Nair Mak B. Arvin John H. Hall 《Natural resources forum》2023,47(3):435-483
This article postulates strong endogenous relationships in lower income countries between institutional quality, financial development and sustained economic growth. These associations were investigated using the vector-error correction model (VECM) and Granger causality method for a sample of 79 countries from 2005 to 2022. The findings show that (1) these variables reinforce each other in the short run. (2) In the long run, both institutional quality and financial development can fuel economic growth. (3) The positive effect of institutional quality on economic growth is greater than that of financial development. Policy implications of these findings are that careful attention should be paid to co-development policies to enhance the institutional quality and the financial system in these economies. Policies should also consider economic growth strategies to enable sustainable economic growth rates. 相似文献
2.
Monitoring and reporting attacks on education in the Democratic Republic of the Congo and Somalia 下载免费PDF全文
Cyril Bennouna Elburg van Boetzelaer Lina Rojas Kinyera Richard Gang Karume Marius Nshombo Leslie Roberts Neil Boothby 《Disasters》2018,42(2):314-335
The United Nations' Monitoring and Reporting Mechanism is charged with documenting six grave violations against children in a time of conflict, including attacks on schools. Many of these incidents, however, remain unreported across the globe. This study explores whether or not a local knowledge base of education and child protection actors in North and South Kivu Provinces, Democratic Republic of the Congo, and in Mogadishu, Somalia, could contribute to a more complete record of attacks on education in those areas. Hundreds of semi‐structured interviews were conducted with key informants across the three settings, and in total 432 attacks on education were documented. Purposive samples of these reports were verified and a large majority was confirmed. Local non‐governmental organisations and education institutions were most knowledgeable about these incidents, but most never reported them to a monitoring authority. The study concludes that attack surveillance and response were largely insufficient, and recommends investing in mechanisms that utilise local knowledge to address these shortcomings. 相似文献
3.
John Kelly 《Journal of Land Use Science》2020,15(2-3):203-220
ABSTRACT Sketch-map-facilitated interviews were conducted in 23 villages in two adjacent regions in the southern Yucatan Peninsula of Mexico – the Maya (and increasingly Mennonite) forest-agriculture mosaic of the Chenes, and the late-20th-century-settlement forest frontier of Calakmul – to determine the frequency and typology of local-scale reserves, including the external (e.g. Payments for Environmental Services programs) and internal sources of their generation. 9% of the study communities are found to satisfy the author’s criteria for deliberate, autochthonous reserves. The static polygon reserve and static map are found to have limited value for understanding the evolving cultural ecologies of these regions. Alternative approaches are discussed, particularly those employed by geographers. 相似文献
4.
van Heezik Yolanda Freeman Claire Davidson Katherine Lewis Blake 《Environmental management》2020,66(1):42-55
Environmental Management - Activities undertaken by householders in their gardens have huge potential to enhance city-wide biodiversity, but programs aimed at activating householders require an... 相似文献
5.
Julie A. Mansfield Yadetsie N. Zaragoza-Rivera John H. Bolte IV 《Traffic injury prevention》2018,19(8):S8-S13
AbstractObjectives: The objective of this study was to determine whether the amount of tension required for proper child restraint system (CRS) installation varies with lower anchor spacing and to determine whether nonexperts can produce adequate tension on wider-than-standard lower anchor configurations.Methods: CRSs were installed by certified child passenger safety technicians (CPSTs; n?=?6 subjects, n?=?72 installations) and nonexperts (n?=?30 subjects, n?=?120 installations) on a mock-up vehicle seat fixture with lower anchors set at 11 (standard), 15, 19, and 23 in. apart from one another. Each CPST installed a rear-facing (RF) infant base, RF convertible, and forward-facing (FF) convertible into each of the 4 spacing configurations in random order. The CPSTs were instructed to tighten the lower connector strap until the tension was exactly at the threshold between passing and failing the 1-in. test. Each nonexpert installed one CRS model into all 4 spacing conditions in random order. Nonexperts were instructed to install the CRS to the best of their ability. The tension produced on the lower connector strap was recorded via load cell in the lower anchor assembly of the vehicle seat. Resultant tension magnitudes were compared across spacing conditions using matched pair t-tests. The CPSTs’ mean 1-in. test threshold values were compared to tensions produced by nonexperts. Installations were visually evaluated for errors and qualitative usability feedback was collected via survey.Results: CPSTs installed the infant base with higher tensions in the 15-, 19-, and 23-in. configurations compared to the standard 11-in. configuration (P = .034, .032, and .003, respectively). The nonexperts installed the infant base with higher tension in the 15- and 23-in. configurations compared to the 11-in. configuration (P = .004 and .026, respectively). The RF convertible and FF convertible installations showed no significant differences in tension among any of the spacing configurations for either group. Only 19% of the nonexperts’ installations were tight enough to pass CPST thresholds, and the pass rate did not vary with respect to lower anchor spacing. In feedback surveys, the nonexpert group did not show a consistent preference for either standard or wider-than-standard lower anchor configurations.Conclusions: The amount of tension required to pass the 1-in. rule did not vary with lower anchor spacing configurations for the RF and FF convertible CRS, but the infant base required more tension in wider anchor configurations. Nonexperts tended to produce less than ideal tension in all configurations, although their tension magnitudes increased for the infant base in wider configurations. 相似文献
6.
A graphics processing unit (GPU) accelerated two-dimensional contamination transport model is developed using the lattice Boltzmann method (LBM). The intrinsic parallel features of LBM make it particularly suitable for implementation on GPUs. After validation with two benchmarks, the model was applied to a cyanide-release accident in the Danjiangkou Reservoir, using a numerical combination of hydrodynamics and solute transport. The results show good agreement with an Environmental Fluid Dynamics Code (EFDC) model. A single GPU workstation speedup reaches 1.58 times that of a central processing unit (CPU) calculation alone. This speedup provides the opportunity for applying the model as a pollution accident information and decision support system for the Middle Route of the South to North Water Diversion Project in China. 相似文献
7.
We investigate the effect of buoyancy on the small-scale aspects of turbulent entrainment by performing direct numerical simulation of a gravity current and a wall jet. In both flows, we detect the turbulent/nonturbulent interface separating turbulent from irrotational ambient flow regions using a range of enstrophy iso-levels spanning many orders of magnitude. Conform to expectation, the relative enstrophy isosurface velocity \(v_n\) in the viscous superlayer scales with the Kolmogorov velocity for both flow cases. We connect the integral entrainment coefficient E to the small-scale entrainment and observe excellent agreement between the two estimates throughout the viscous superlayer. The contribution of baroclinic torque to \(v_n\) is negligible, and we show that the primary reason for reduced entrainment in the gravity current as compared to the wall-jet are 1) the reduction of \(v_n\) relative to the integral velocity scale \(u_T\); and 2) the reduction in the surface area of the isosurfaces. 相似文献
8.
Tolis Evangelos I. Karanotas Tilemachos Svolakis Grigoris Panaras George Bartzis John G. 《Environmental science and pollution research international》2021,28(37):51232-51241
Environmental Science and Pollution Research - Despite that commuters spend only 5.5% of their time in cabin vehicles, their exposure to harmful air pollutants, originated from the vehicle itself,... 相似文献
9.
Environmental Economics and Policy Studies - Rising sea levels necessitate careful consideration of different forms of coastal protection but cost-benefit analysis is limited when important... 相似文献
10.
Mughal Nafessa Kashif Maryam Arif Asma Guerrero John William Grimaldo Nabua Wilson C. Niedbała Gniewko 《Environmental science and pollution research international》2021,28(46):65116-65126
Environmental Science and Pollution Research - This study aims to re-examine the impacts of monetary and fiscal policy on environmental quality in ASEAN countries from 1990 to 2019. We utilized the... 相似文献