全文获取类型
收费全文 | 357篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 16篇 |
废物处理 | 6篇 |
环保管理 | 96篇 |
综合类 | 45篇 |
基础理论 | 100篇 |
环境理论 | 2篇 |
污染及防治 | 64篇 |
评价与监测 | 23篇 |
社会与环境 | 13篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 16篇 |
2014年 | 10篇 |
2013年 | 32篇 |
2012年 | 18篇 |
2011年 | 18篇 |
2010年 | 17篇 |
2009年 | 18篇 |
2008年 | 18篇 |
2007年 | 18篇 |
2006年 | 20篇 |
2005年 | 17篇 |
2004年 | 14篇 |
2003年 | 23篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 46 毫秒
231.
Understanding the evolutionary processes from recent demographic history is especially difficult for interstitial organisms
due to their poorly known natural history. In this study, the genetic variation and population history of the four Ototyphlonemertes (Diesing in Sitz ber Math Nat Kl Akad Wiss Wien 46:413–416, 1863) species were evaluated from samples collected along the Brazilian coast (between 27°31′S and 13°00′W) in 2006. The mitochondrial
region cytochrome c oxidase subunit 3 (COX3) is analyzed to assess the genetic variation of these dioecious species. Although these species have
a sympatric distribution along the coast, our data suggest that their levels of differentiation and their demographic histories
differ sharply. There is strong evidence of gene flow among demes in O. erneba and O. evelinae, and their level of structuring is much lower than for the other two species. Indeed, the COX3 fragment reveals cryptic lineages
in O. lactea and O. parmula. The results seem to contradict the high genetic structuring and low intrapopulational variability expected with the ecological
constriction and habitat discontinuity faced by these organisms, meaning that there might be gene flow among populations or
their dispersal capability has been underestimated. 相似文献
232.
Adjusting the timing of hatching to changing environmental conditions has fitness costs in blue tits
Edward?KluenEmail author Maaike?E.?de?Heij Jon?E.?Brommer 《Behavioral ecology and sociobiology》2011,65(11):2091-2103
After laying the first egg, a bird can, to a certain extent, adjust the hatching date of the brood to environmental conditions.
However, costs of this adjustment have remained largely unexplored. We studied potential costs of hatching delay in a population
of blue tits in southern Finland. We explored the factors underlying hatching delay and investigated the association between
hatching delay, clutch hatchability and female body condition. Finally, we reciprocally cross-fostered a large number of broods
irrespective of their experienced hatching delay to address possible downstream effects of hatching delay on developmental
parameters in offspring. We found that hatching delay was associated with early laying dates and low mean temperatures during
the egg-laying phase. Furthermore, we found evidence that delayed hatching negatively affected the breeding performance. Hatchability
of the clutch was lowered and the breeding female was energetically impaired, resulting in smaller clutch sizes, lower female
body mass at hatching and lowered survival of nestlings reared in nests that had experienced a long hatching delay. In addition,
delayed hatching had a significant negative effect on the body mass of nestlings prior to fledging. However, ultimately we
did not find evidence that delayed hatching affected survival of the breeding female nor recruitment of fledglings in the
local breeding population. Our study demonstrates that environmental conditions during egg laying can have lasting effects
throughout the breeding and nestling phase. Furthermore, our results emphasize the importance of energetic tradeoffs by breeding
females during the early breeding phase to manage reproductive costs. 相似文献
233.
Hansen S Nieboer E Sandanger TM Wilsgaard T Thomassen Y Veyhe AS Odland JØ 《Journal of environmental monitoring : JEM》2011,13(8):2143-2152
The objective of this study was to investigate changes in the levels of toxic and essential elements in maternal blood during pregnancy and subsequently. A subset of 211 pregnant women from the North Norwegian Mother-and-Child Study was included. Blood samples were collected during the 2(nd) trimester (P1) and postpartum (day 3, P2; and 6 weeks, P3) in different regions of northern Norway, and were analyzed for a suite of 10 selected elements. The latter feature three general but distinct concentration patterns across the three collection periods, namely: progressive increase [Group 1: As, Cd (non-smokers only), Mn, Pb and Zn]; V-shaped, with a minimum at P2 [Group 2: Cd (smokers), Hg, Mo and Se]; and downward V, with a maximum at P2 [Group 3: Co and Cu]. These trends are interpreted in the context of underlying metabolic, hematological and physiological changes that occur in mothers, as well the biochemistry and accumulation preferences of these elements within the whole blood compartment and breast milk. Implications for biomonitoring strategies are discussed. In a multivariable analysis of the P1 data, fish consumption was a robust positive predictor for Hg (p < 0.02), As (p < 0.01) and Se (p ≤ 0.001) blood concentrations, multivitamin intake for Se (p < 0.001), and parity for Co (p < 0.002); age reached significance only for Hg (p < 0.001). An inverse association was observed between parity and Hg (p < 0.05). For the other elements, predictor patterns were not evident. 相似文献
234.
Elie Gaget Alison Johnston Diego Pavón-Jordán Aleksi S. Lehikoinen Brett K. Sandercock Alaaeldin Soultan Luka Božič Preben Clausen Koen Devos Cristi Domsa Vitor Encarnação Sándor Faragó Niamh Fitzgerald Teresa Frost Clemence Gaudard Lívia Gosztonyi Fredrik Haas Menno Hornman Tom Langendoen Christina Ieronymidou Leho Luigujõe Włodzimierz Meissner Tibor Mikuska Blas Molina Zuzana Musilová Jean-Yves Paquet Nicky Petkov Danae Portolou Jozef Ridzoň Laimonas Sniauksta Antra Stīpniece Norbert Teufelbauer Johannes Wahl Marco Zenatello Jon E. Brommer 《Conservation biology》2022,36(4):e13877
Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation-relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) changed in response to increases in temperature over 25 years in 26 European countries. We measured community reshuffling based on abundance time series collected under the International Waterbird Census relative to N2K sites’ conservation targets, funding, designation period, and management plan status. Waterbird community composition in sites explicitly designated to protect them and with management plans changed more quickly in response to climate warming than in other N2K sites. Temporal community changes were not affected by the designation period despite greater exposure to temperature increase inside late-designated N2K sites. Sites funded under the LIFE program had lower climate-driven community changes than sites that did not received LIFE funding. Our findings imply that efficient conservation policy that helps waterbird communities respond to climate warming is associated with sites specifically managed for waterbirds. 相似文献
235.
Stephen E. Lewis Jon E. Brodie Zoë T. Bainbridge Ken W. Rohde Aaron M. Davis Bronwyn L. Masters Mirjam Maughan Michelle J. Devlin Jochen F. Mueller Britta Schaffelke 《Environmental pollution (Barking, Essex : 1987)》2009,157(8-9):2470-2484
The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of large-scale datasets. Here we present results of a study tracing pesticide residues from rivers and creeks in three catchment regions to the adjacent marine environment. Several pesticides (mainly herbicides) were detected in both freshwater and coastal marine waters and were attributed to specific land uses in the catchment. Elevated herbicide concentrations were particularly associated with sugar cane cultivation in the adjacent catchment. We demonstrate that herbicides reach the Great Barrier Reef lagoon and may disturb sensitive marine ecosystems already affected by other pressures such as climate change. 相似文献
236.
237.
Carla Ximena Salinas Jon Mendieta 《Mitigation and Adaptation Strategies for Global Change》2013,18(5):659-672
Climate change will further increase the risk of desertification, which is already affecting large areas of the world. Many countries are making investments for the implementation of mitigation and adaptation strategies to combat desertification. The long term effectiveness of these strategies necessarily require a socioeconomic return for its sustainability. The main goal of our paper is to assess the relation between the mitigation and adaptation investments and the socio-economy of the rural population. The area of study is located in north-central Chile. The northern regions are mostly composed by arid land, which can be considered as a marginal area for agriculture. The area formed by the southern regions is optimal for the agricultural activity which is characterized by an industrialized agriculture with and increased use of technology. The indicators we have used for our study are the following: the Investments provided by the Chilean Agriculture Livestock and Forestry (ALF) promotion agencies, the ALF Gross Domestic Product (GDP) and the Population Employed in ALF. The results show that the relationship between the investments and the socioeconomy varies among the regions analyzed. Investments are positively correlated (P?≤?0.05) with the ALF GDP and the labor in ALF in the northern regions, but do not seem to be directly related to labor in ALF in the southern regions (P?≥?0.05). Therefore, our conclusion is that the Investments are significantly relevant for the agricultural activity in the arid northern regions, while in the southern regions they have no direct impact on the labor in ALF. 相似文献
238.
Measuring safety performance is becoming increasingly important in many high-risk industries such as atomic power, the chemical industry, offshore oil production, air traffic control and construction. Much has been done to study the antecedents/factors that shape the safety culture and safety climate in these types of industries, but almost no research has been conducted into another high-risk industry – shipping. Based on the safety orientation model (SOM) and a review of items and scales used in surveys of safety climate and safety culture, a safety orientation scale (SOS) was developed and refined through the use of multivariate statistics. This study was conducted with a sample of seafarers sailing on Norwegian-owned vessels. A total of 2558 questionnaires were returned from 141 vessels and 16 shipping companies, giving a calculated response rate of 70%.The study showed that replicating previous studies on the sample of seafarers demonstrated a large degree of stability in scales and items across both industries and nations.Exploratory factor analysis (EFA) is the most commonly adopted approach to the development of scales of safety climate and culture scale reported in the literature, and factor retention seems to be the most important decision in EFA. In the present study several rules to determine the number of factors and items retained are applied, and a comparison is made of a short form of latent root criterion (SFLRC) and parallel criterion (PC). SFLRC is found to be the superior method for the present data set.Confirmatory factor analysis (CFA) did not support the preliminary SOM of 12 dimensions (13 dimensions, since one of the 12 dimensions was split during the CFA procedure); however, a re-specification of the model on the basis of the CFA for four different behavioural measures gave a simplified and well-defined model with seven factors and 22 items. 相似文献
239.
Xi Liang David Reiner Jon Gibbins Jia Li 《International Journal of Greenhouse Gas Control》2009,3(6):787-792
Making new plants CO2 capture ready (CCR) would enable them to retrofit to capture CO2 at a later date at lower cost when the appropriate policy and/or economic drivers are in place. In order to understand the economic value and investment characteristics of making new plants CCR in China, a typical 600 MW pulverised coal-fired ultra-supercritical power plant, locating in Guangdong province, was examined. Combined with an engineering assessment, costs were estimated for different CCR scenarios. To analyze CCR investment opportunities, the paper applies a cash flow model for valuing capture options and CCR investment. Results were obtained by Monte-Carlo simulation, based on engineering surveys and an IEA GHG CCR study, as well as plant performance information and expert projections on carbon prices, coal prices and electricity prices.CCR investments are justified by factors such as higher retrofitting probabilities, lower early closure probabilities and fair economic return. However, the economic case for CCR largely depends on two factors: (a) whether the original plant is retrofittable without CCR; and (b) the type of investments made, for example, investments essential to CCR tend to be more economic than additional non-essential CCR features such as clutched low pressure turbines. The carbon price and discount rate were found to have significant impacts on the economics of CCR. Overall, it appears that the value of the ‘capture options’ that CCR generates for retrofitting CCS is significant, and so could justify a modest CCR investment, even assuming the original plant is retrofittable without CCR. It was also found the value of CCR might be significantly understated if the range of potential retrofitting dates is artificially constrained. 相似文献
240.
Cost estimates are frequently developed to evaluate hazardous‐waste‐site cleanup options in support of a site investigation, remedy selection decision, or assessment of environmental liabilities. The accuracy of the cost estimate depends largely on the quality of the information available at the time it is prepared. This article presents a practical guide to developing a cleanup cost estimate. It includes information on how to document assumptions, use the latest technical resources, and perform basic adjustments to account for uncertainty and the time value of money. The content is based upon a recent guidance document issued by the U.S. Environmental Protection Agency and U.S. Army Corps of Engineers entitled A Guide to Developing and Documenting Cost Estimates during the Feasibility Study (USEPA, 2000). © 2001 John Wiley & Sons, Inc. 相似文献