全文获取类型
收费全文 | 29892篇 |
免费 | 337篇 |
国内免费 | 248篇 |
专业分类
安全科学 | 1003篇 |
废物处理 | 1458篇 |
环保管理 | 3987篇 |
综合类 | 4482篇 |
基础理论 | 7774篇 |
环境理论 | 8篇 |
污染及防治 | 7401篇 |
评价与监测 | 2135篇 |
社会与环境 | 2044篇 |
灾害及防治 | 185篇 |
出版年
2023年 | 142篇 |
2022年 | 263篇 |
2021年 | 319篇 |
2020年 | 196篇 |
2019年 | 243篇 |
2018年 | 437篇 |
2017年 | 464篇 |
2016年 | 720篇 |
2015年 | 533篇 |
2014年 | 856篇 |
2013年 | 2495篇 |
2012年 | 1020篇 |
2011年 | 1352篇 |
2010年 | 1106篇 |
2009年 | 1144篇 |
2008年 | 1412篇 |
2007年 | 1330篇 |
2006年 | 1223篇 |
2005年 | 1084篇 |
2004年 | 1040篇 |
2003年 | 996篇 |
2002年 | 934篇 |
2001年 | 1091篇 |
2000年 | 772篇 |
1999年 | 484篇 |
1998年 | 365篇 |
1997年 | 383篇 |
1996年 | 401篇 |
1995年 | 465篇 |
1994年 | 398篇 |
1993年 | 343篇 |
1992年 | 378篇 |
1991年 | 359篇 |
1990年 | 329篇 |
1989年 | 323篇 |
1988年 | 297篇 |
1987年 | 249篇 |
1986年 | 248篇 |
1985年 | 250篇 |
1984年 | 269篇 |
1983年 | 256篇 |
1982年 | 270篇 |
1981年 | 227篇 |
1980年 | 167篇 |
1979年 | 185篇 |
1978年 | 166篇 |
1977年 | 134篇 |
1975年 | 139篇 |
1973年 | 168篇 |
1972年 | 143篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
641.
Andrew S. Jones Allan A. Andales Jos L. Chvez Cullen McGovern Garvey E.B. Smith Olaf David Steven J. Fletcher 《Journal of the American Water Resources Association》2020,56(2):201-211
We apply predictive weather metrics and land model sensitivities to improve the Colorado State University Water Irrigation Scheduler for Efficient Application (WISE). WISE is an irrigation decision aid that integrates environmental and user information for optimizing water use. Rainfall forecasts and verification performance metrics are used to estimate predictive rainfall probabilities that are used as input data within the irrigation decision aid. These input data errors are also used within a land model sensitivity study to diagnose important prognostic water movement behaviors for irrigation tool development purposes simultaneously performing the analysis in space and time. Thus, important questions such as “how long can a crop water application be delayed while maintaining crop yield production?” are addressed by evaluating crop growth stage interactions as a function of soil depth (i.e., space), rainfall events (i.e., time), and their probabilistic uncertainties. Editor’s note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series. 相似文献
642.
This research seeks for improved understanding regarding the interaction of meaningful work and the work–family interface. Existing literature suggests that experiencing a sense of calling toward work makes the work domain particularly salient to employees compared to other life domains. In this article, we draw on this idea, rooted in identity theory, to hypothesize that a sense of calling toward work diminishes the effects of work–family conflict and work–family enrichment on employee's job and life satisfaction. We test these ideas in two studies. First, we surveyed an alumni sample of 598 employees from various jobs, industries, and job levels. Then, in a constructive replication, we surveyed 327 employees using a time-lagged design. Calling was found to significantly buffer the effect of work–family conflict on job satisfaction in Study 2, but not Study 1. Calling did not buffer the effect of conflict on life satisfaction in either study. However, both studies demonstrated that calling attenuated (substituted for) the effect of work–family enrichment on job satisfaction. Study 1 supported the idea that calling attenuates the effect of enrichment on life satisfaction; however, this interactive effect was reversed in Study 2, contrary to expectations. We discuss implications for theory and practice related to callings and career choices, as well as for the role of calling and work identity in the work–family interface. 相似文献
643.
Hewitt Richard J. Pera Florencia A. Garca-Martn Mara Gaudry-Sada Karl-Heinz Hernndez-Jimnez Vernica Bieling Claudia 《Environmental management》2020,65(3):334-354
Environmental Management - Landscapes are changing, with rural areas becoming increasingly urbanized. Children and adolescents are underrepresented in the sense-of-place literature. Our study aimed... 相似文献
644.
Robert A. Montgomery Madeline Carr Charlie R. Booher Abigail M. Pointer Brendan M. Mitchell Natalie Smith Keegan Calnan Georgina M. Montgomery Mordecai Ogada Daniel B. Kramer 《Conservation biology》2020,34(4):915-924
In November 1928, Theodore Jr. and Kermit Roosevelt led an expedition to China with the expressed purpose of being the first Westerners to kill the giant panda (Ailuropoda melanoleuca). The expedition lasted 8 months and resulted in the brothers shooting a giant panda in the mountains of Sichuan Province. Given the concurrent attention in the popular press describing this celebrated expedition, the giant panda was poised to be trophy hunted much like other large mammals around the world. Today, however, the killing of giant pandas, even for the generation of conservation revenue, is unthinkable for reasons related to the species itself and the context, in time and space, in which the species was popularized in the West. We found that the giant panda's status as a conservation symbol, exceptional charisma and gentle disposition, rarity, value as a nonconsumptive ecotourism attraction, and endemism are integral to the explanation of why the species is not trophy hunted. We compared these intrinsic and extrinsic characteristics with 20 of the most common trophy-hunted mammals to determine whether the principles applying to giant pandas are generalizable to other species. Although certain characteristics of the 20 trophy-hunted mammals aligned with the giant panda, many did not. Charisma, economic value, and endemism, in particular, were comparatively unique to the giant panda. Our analysis suggests that, at present, exceptional characteristics may be necessary for certain mammals to be excepted from trophy hunting. However, because discourse relating to the role of trophy hunting in supporting conservation outcomes is dynamic in both science and society, we suspect these valuations will also change in future. 相似文献
645.
Robert A. Montgomery Kendi Borona Herbert Kasozi Tutilo Mudumba Mordecai Ogada 《Conservation biology》2020,34(5):1122-1130
Conservation projects subscribing to a community-based paradigm have predominated in the 21st century. We examined the context in which the phrase was coined and traced its growth over time. Community-based conservation first appeared in the literature in the early 1990s; but grew little until after the 5th World Parks Congress in 2003. Thereafter, publications describing community-based conservation approaches increased exponentially. The conference theme was Benefits Beyond Boundaries, and its goal was to provide an economic model based on revenue accrued from conservation fundraising and ecotourism to support ecosystems, wildlife, and people, particularly in the Global South. Such models tended not to incorporate, as a core principle, the heritage of local human communities. Human heritage varies substantially over time and space making generalization of conservation principles across scales challenging. Pitfalls that have grown out of the community-based conservation approaches in the Global South include fortress conservation, conservation militarism, consumptive and nonconsumptive ecotourism, and whiz-bang solutions. We propose 10 tenets in a human heritage-centered conservation framework (e.g., engage in conservation practices using local languages, thoughtfully propose and apply solutions consistent with human heritage, provide clear professional development pathways for individuals from local communities, and promote alternative revenue-generating programs centered in local communities, among others). Progressive philosophies can derive from authentic and ethical integration of local communities in conservation practice. 相似文献
646.
LaPlue Lawrence D. Erickson Christopher A. 《Environmental Economics and Policy Studies》2020,22(2):217-245
Environmental Economics and Policy Studies - U.S. output has steadily outpaced the rise in greenhouse gas (GHG) emissions over the past several decades. The decoupling of these two trends... 相似文献
647.
Murshed Mutee Dkhil Mohamed A. Al-Shaebi Esam M. Qasem Mahmood A. A. Mares Mohammed M. Aljawdah Hossam M. A. Alojayri Ghada Abdel-Gaber Rewaida Al-Quraishy Saleh 《Environmental science and pollution research international》2020,27(32):40054-40060
Environmental Science and Pollution Research - Malaria is a dangerous disease affecting millions around the globe. Biosynthesized nanoparticles are used against a variety of diseases including... 相似文献
648.
Abdelnour Sameh A. Yang Chun-Yan Swelum Ayman A. Abd El-Hack Mohamed E. Khafaga Asmaa F. Abdo Mohamed Shang Jiang-Hua Lu Yang-Qing 《Environmental science and pollution research international》2020,27(31):38472-38490
Environmental Science and Pollution Research - Global warming is considered as the main environmental stress affecting ecosystems as well as physiological and biochemical characteristics, and... 相似文献
649.
Russian Journal of Ecology - Analysis of hunting samples of the Kamchatka sable population for 2001–2013 has revealed changes in the reproductive parameters of females over the period from... 相似文献
650.
Seventy-two squares of 100 ha were selected by stratified random sampling with probabilities proportional to size (pps) to survey landscape changes in the period 1996–2003. The area of the plots times the urbanization pressure was used as a size measure. The central question of this study is whether the sampling with probabilities proportional to size leads to gain in precision compared to equal probability sampling. On average 1.03 isolated buildings per 100 ha have been built, while 0.90 buildings per 100 ha have been removed, leading to a net change of 0.13 building per 100 ha. The area with unspoiled natural relief has been reduced by 2.3 ha per 100 ha, and the length of linear relicts by 137 m per 100 ha. On average 74 m of linear green elements have been planted per 100 ha, while 106 m have been removed, leading to a net change of −31 m per 100 ha. For the state variables ‘unspoiled natural relief', ‘ linear relicts', ‘removed linear green elements', and ‘new – removed linear green elements' there is a gain in precision due to the pps-sampling. For the remaining state variables there is no gain or even a loss of precision (`new buildings', ‘removed buildings', ‘new – removed buildings', ‘new linear green elements'). Therefore, if many state variables must be monitored or when interest is not only in the change but also in the current totals, we recommend to keep things simple, and to select plots with equal probability. 相似文献