全文获取类型
收费全文 | 255篇 |
免费 | 2篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 19篇 |
环保管理 | 31篇 |
综合类 | 42篇 |
基础理论 | 64篇 |
污染及防治 | 65篇 |
评价与监测 | 11篇 |
社会与环境 | 22篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 25篇 |
2012年 | 20篇 |
2011年 | 21篇 |
2010年 | 16篇 |
2009年 | 12篇 |
2008年 | 19篇 |
2007年 | 18篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有260条查询结果,搜索用时 172 毫秒
61.
Robert Coats Laurel Collins Joan Florsheim Darrell Kaufman 《Environmental management》1985,9(1):35-48
A study on sediment transport and channel change was conducted on Zayante Creek and the lower San Lorenzo River in Santa Cruz County, California. A rainstorm with a recurrence interval locally in excess of 150 years occurred during the study year, 1982 WY. Stream surveys indicated that significant aggradation occurred during and after the peak flood. Upper study reaches were substantially recovered after high flows of early April, but the lower study reaches still had significant filling of pools and burial of riffles by sand. Increases in width-depth ratio were minor and localized in upper reaches, but were significant in lower reaches. Large inputs of sand, primarily from landsliding, altered the sediment transport regime. A higher proportion of the bedload is now transported by lower flows than before the January event. Roads and sand quarries contributed significantly to sediment input to the stream. A proposed dam may alter the sediment transport regime of Zayante Creek. Mitigating the effects of this dam on downstream fish habitat may require occasional bankfull discharges. 相似文献
62.
The birth prevalence rate of each common autosomal trisomy generally increases with advancing maternal age and there is a substantial fetal loss rate between late first trimester and term. The literature is reviewed in order to provide the best estimates of these rates, taking account where possible of biases due to prenatal diagnosis and selective termination of pregnancy. There is an almost exponential increase in Down syndrome birth prevalence between ages 15 and 45 but at older ages the curve flattens. There is no evidence of the claimed relatively high birth prevalence at extremely low ages. Gestation-specific intra-uterine fetal loss rates are estimated by follow-up of women declining termination of pregnancy after prenatal diagnosis, comparison of observed rates with those expected from birth prevalence and comparison of age-specific curves developed for prenatal diagnosis and birth. Down syndrome fetal loss rates reduce with gestation and increase with maternal age. Edwards and Patau syndrome birth prevalence is approximately 1/8 and 1/13 that of Down syndrome overall, although the ratio differs according to maternal age, particularly for Patau syndrome where it reduces steadily from 1/9 to 1/19. Fetal loss rates are higher for Edwards and Patau syndromes than for Down syndrome. 相似文献
63.
64.
65.
Water quality in the Chesapeake Bay has deteriorated over recent years. Historically, fishing has contributed to the region's local economy in terms of commercial and recreational harvests. A contingent behavior model is used to estimate welfare measures for charter fishing participants with regard to a hypothetical improvement in water quality. Using a truncated Poisson count model corrected for endogenous stratification, it was found that charter fishers not only contribute to the local market economy, but they also place positive non-market value on preserving the Bay's water quality. Using two estimates for travels costs it is estimated that the individual consumer surplus is $200 and $117 per trip, and the average individual consumer surplus values for an improvement in water quality is $75 and $44 for two models estimated. 相似文献
66.
Fernández Pilar Rose Neil L. Vilanova Rosa M. Grimalt Joan O. 《Water, Air, & Soil Pollution: Focus》2002,2(2):261-274
Spheroidal carbonaceous particles (SCP) and polycyclicaromatic hydrocarbons (PAH) have been measured in the dated sediment cores of 10 remote lakes distributed across Europe. The geographic trends were evaluated by examination of the superficial sediment fluxes and total sediment inventories. The highest levels of both markers were observed in the Eastern European lakes whereas the minimal values corresponded to the lake located in the Arctic. However, this SCP-PAH correlation was not observed after exclusion of the end member lakes from the series. The temporal trends of both pollutant markers are consistent with the history of pyrolytic emissions over Europe. However, the downcore SCP distributions are shorter than the PAH profiles in nearly all lakes. The differences are probably related to the different size particle fractions involved in the measurement of each marker, >5 and >1 m for SCP and PAH, respectively. Thus, the two proxies probably reflect pollution inputs from closer (SCP) and more distant sites (PAH). 相似文献
67.
Joan Iverson Nassauer Sandra E. Kosek Robert C. Corry 《Journal of the American Water Resources Association》2001,37(6):1439-1443
ABSTRACT: Appearances matter for managing riparian landscapes because the appearance of landscapes affects public willingness to accept plans and designs that improve ecological quality. Riparian landscape design and planning should respect and strategically incorporate characteristics that the public values and expects to see. Such design can be quite novel in its ecological effects, but it also should be sufficiently familiar in appearance to correspond with cultural values. This paper describes some influential cultural values for riparian landscapes and demonstrates how attention to such values supports public acceptance of ecologically innovative design in rural and urban watersheds. 相似文献
68.
Bartolome J Penuelas J Filella I Llusia J Broncano MJ Plaixats J 《Journal of environmental biology / Academy of Environmental Biology, India》2007,28(4):697-700
Plants usually emit large amount and varieties of volatiles after being damaged by herbivores. However, analytical methods for measuring herbivore-induced volatiles do not normally monitor the whole range of volatiles and the response to large herbivores such as large mammals is much less studied than the response to other herbivores such as insects. In this paper we present the results of using a highly sensitive proton transfer reaction-mass spectrometry (PTR-MS) technique that allows simultaneous monitoring of leaf volatiles in the pptv range. The resulting mass scans in air over Mediterranean shrubland browsed by horses show 70 to 100% higher concentrations of the masses corresponding to mass fragments 57, 43 and 41 (mostly hexenals, acetone and acetic acid) than scans over control non-browsed shrubland. These compounds are biogeochemically active and they are significant components of the volatile organic carbon found in the atmosphere. They influence the performance of living organisms and, the chemical and physical processes of Earth's atmosphere. 相似文献
69.
Thanigaivel S. Rajendran Saravanan Gnanasekaran Lalitha Chew Kit Wayne Tran Dang Thuan Tran Hoang-Dung Nghia Nguyen Khoi Show Pau Loke 《Environmental Chemistry Letters》2023,21(2):821-837
Environmental Chemistry Letters - Fossil fuel depletion and carbon dioxide emissions are calling for carbon neutral energies such as algal biofuels, yet actual production of agal biofuels is... 相似文献
70.
Joan Iliopoulou-Georgudaki Athanasios Kalogeras Panagiotis Konstantinopoulos 《国际发展与全球生态学杂志》2016,23(2):143-153
A process is presented to facilitate the sustainable management and development of tourist destinations. Based on a specific reforming of the Limits of Acceptable Change planning system and combined with the Tourism Carrying Capacity concept into a common framework, specific steps are described to integrate environmental, social and economic information of a tourist destination into indicators, which are afterwards compared with reference conditions. The Leopold matrix is applied to identify and classify restrictions of development and provide the basis for negotiations between managers, stakeholders and local communities. Through a feedback process of continuous monitoring and adjustment, the aim is to focus developmental activities on restricting factors until all indicators upgrade to reference. A case study at a Greek coastal municipality (Ilida – western Greece) is applied to demonstrate the process. Activity zones are identified and 18 indicators are selected. Results suggest high potential for tourism development of the area. However, low scores are assigned to 8/18 indicators, reflecting restrictions, requiring priority under a sustainable development plan. The proposed process offers managers and stakeholders the ability to easily visualize/identify restrictions and assign developmental priorities within a step-by-step upgrading process, toward the sustainable management and development of tourist destinations. 相似文献