全文获取类型
收费全文 | 606篇 |
免费 | 12篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 24篇 |
环保管理 | 140篇 |
综合类 | 48篇 |
基础理论 | 150篇 |
环境理论 | 1篇 |
污染及防治 | 132篇 |
评价与监测 | 65篇 |
社会与环境 | 24篇 |
灾害及防治 | 15篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 4篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 17篇 |
2015年 | 9篇 |
2014年 | 27篇 |
2013年 | 41篇 |
2012年 | 25篇 |
2011年 | 35篇 |
2010年 | 34篇 |
2009年 | 26篇 |
2008年 | 38篇 |
2007年 | 33篇 |
2006年 | 38篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 27篇 |
2002年 | 20篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有626条查询结果,搜索用时 31 毫秒
301.
Ayesha I. T. Tulloch Micha V. Jackson Elisa Bayraktarov Alexander R. Carey Diego F. Correa-Gomez Michael Driessen Ian C. Gynther Mel Hardie Katherine Moseby Liana Joseph Harriet Preece Andrés Felipe Suarez-Castro Stephanie Stuart John C. Z. Woinarski Hugh P. Possingham 《Conservation biology》2023,37(2):e14032
Monitoring is critical to assess management effectiveness, but broadscale systematic assessments of monitoring to evaluate and improve recovery efforts are lacking. We compiled 1808 time series from 71 threatened and near-threatened terrestrial and volant mammal species and subspecies in Australia (48% of all threatened mammal taxa) to compare relative trends of populations subject to different management strategies. We adapted the Living Planet Index to develop the Threatened Species Index for Australian Mammals and track aggregate trends for all sampled threatened mammal populations and for small (<35 g), medium (35–5500 g), and large mammals (>5500 g) from 2000 to 2017. Unmanaged populations (42 taxa) declined by 63% on average; unmanaged small mammals exhibited the greatest declines (96%). Populations of 17 taxa in havens (islands and fenced areas that excluded or eliminated introduced red foxes [Vulpes vulpes] and domestic cats [Felis catus]) increased by 680%. Outside havens, populations undergoing sustained predator baiting initially declined by 75% but subsequently increased to 47% of their abundance in 2000. At sites where predators were not excluded or baited but other actions (e.g., fire management, introduced herbivore control) occurred, populations of small and medium mammals declined faster, but large mammals declined more slowly, than unmanaged populations. Only 13% of taxa had data for both unmanaged and managed populations; index comparisons for this subset showed that taxa with populations increasing inside havens declined outside havens but taxa with populations subject to predator baiting outside havens declined more slowly than populations with no management and then increased, whereas unmanaged populations continued to decline. More comprehensive and improved monitoring (particularly encompassing poorly represented management actions and taxonomic groups like bats and small mammals) is required to understand whether and where management has worked. Improved implementation of management for threats other than predation is critical to recover Australia's threatened mammals. 相似文献
302.
Summary In a population of the splendid fairy-wren Malurus splendens, we describe 202 intrusions by solitary adult males in full breeding plumage into the territories of conspecifics. Intrusions were not secretive and although silent they involved conspicuous flight above the vegetation and several characteristic display elements, including petal-carrying. Fifteen intrusions were observed in the 2 months before eggs were laid, but the rest occurred during the period of nest-building and egg-laying when the breeding female was presumed to be fertile, and were by males from adjacent territories. A high level of extra-pair fertilization has previously been determined in this species and we interpret many of these intrusions as attempts by males to obtain extra-pair copulations (EPC); we call this activity philandering. The costs and benefits of EPC for males and females are discussed and the promiscuous mating strategy of M. splendens is contrasted with the persistent social pairing in stable groups of this long-lived cooperatively breeding species.Offprint requests to: I. Rowley 相似文献
303.
Ian Christoplos 《Disasters》1998,22(1):1-20
The role of local service institutions is not a major focus of current discourse on humanitarianism and complex emergencies. These institutions, in the few places where they are mentioned, are usually presented as either the seed of civil society and future democracy, or as pawns and components of the predatory economic, political and military élites. Few would deny that examples can be found which conform to both of these stereotypes. This simplistic representation of local institutions ignores the perspectives of the actors themselves — the nurses, extension agents, school teachers and others who actually staff most NGO-supported projects. The debate has focused on what ‘we’ should do; the moral dilemmas of aid agencies and their expatriate staff, inevitably leading to the question of whether or not humanitarian workers should stay or leave situations in which aid may be causing more harm than good. Without denying the fundamental importance of these issues, it is important to consider also how the discourse has unfortunately moved away from those humanitarian workers who have no such choice, since they live there. Current concerns about keeping humanitarian aid from feeding local political and military struggles may inadvertently and paradoxically serve to constrain room for man?uvre in the field, particularly among those individuals with the greatest tacit understanding of the predatory environment. There is a need to understand how actors in local service institutions make sense of their own situations, including the factors which frame their moral dilemmas and their day-to-day choices. By analysing the organisational processes within local service institutions, this study is intended to provoke consideration of how these individuals and their institutions may be effectively supported in complex emergencies through a focus on how they themselves deal with danger and complexity. It is suggested that there is a value in considering the lessons learnt in recent years about how service organisations in the North function in turbulent environments. This experience points to the importance of allowing workers the discretion to develop a relationship with their clients, and in so doing make sense of a confusing and ambivalent environment. 相似文献
304.
305.
The decomposition of sodium dodecylbenzene sulfonate (SDBS) in water by means of ultrasound irradiation at 20kHz was investigated. Experiments were conducted at surfactant concentrations of 175, 260 and 350 mg l(-1), liquid volumes of 120, 170 and 220 ml, temperatures of 20, 30 and 45 degrees C and applied power of 40, 80 and 125 W. The extent of degradation was followed monitoring substrate and organic carbon concentrations, while hydrogen peroxide concentration was also measured; the latter is a product of water sonolysis due to hydroxyl radical recombination. 80% SDBS conversion was achieved after 120 min of sonication at 125 W and 30 degrees C; nonetheless, SDBS and its degradation intermediates proved difficult to oxidise as only about 20-25% of the initial carbon content was transformed to carbon dioxide. At the initial stages of the reaction, degradation rate appears to be only weakly dependent on the substrate concentration with the rate increasing from 3.1 to 4 mg l(-1)min(-1) with increasing concentration from 175 to 350 mg l(-1). Degradation appears to occur at the bubble-liquid interface through hydroxyl radical-mediated reactions whose role was established by performing experiments in the presence of radical scavengers, namely potassium bromide and sodium benzoate. Degradation rates increased with increasing power and decreasing temperature and volume. 相似文献
306.
Ian G. McKendry 《Journal of the Air & Waste Management Association (1995)》2013,63(3):443-452
ABSTRACT Three years of hourly averaged PM10 (particulate matter less than 10 Lrm in diameter) tapered element oscillating microbalance (TEOM) data from 10 sites in the large coastal valley incorporating Greater Vancouver were used to investigate the spatiotemporal dimensions and air pollution meteorology of particulate pollution. During the period studied, the provincial “acceptable” objective daily concentration of 50 μg m-3 was exceeded at 7 of the 10 sites. The highest annual, seasonal, and maximum hourly concentrations were recorded at Abbotsford in the central valley. Mean seasonal PM10 concentrations were highest in the wintertime in the western Lower Fraser Valley (LFV) and in the summertime at the central and eastern valley locations. Within the network, interstation correlations of daily average concentrations exceed 0.8 at interstation distances less than 20 km and decrease thereafter. For daily maximum concentrations (hourly), interstation correlations decrease sharply with distance. Meteorological conditions responsible for elevated par-ticulate concentrations in the LFV are associated with (1) short periods (1- to 3-hr duration) of reduced dispersion during summer nights at sites close to primary sources, (2) summer anticyclonic conditions when photochemical pollutant concentrations build up across the entire valley, and (3) occasional wintertime “gap wind” events in the eastern valley. 相似文献
307.
Predicting leaf physiology from simple plant and climate attributes: a global GLOPNET analysis. 总被引:2,自引:0,他引:2
Knowledge of leaf chemistry, physiology, and life span is essential for global vegetation modeling, but such data are scarce or lacking for some regions, especially in developing countries. Here we use data from 2021 species at 175 sites around the world from the GLOPNET compilation to show that key physiological traits that are difficult to measure (such as photosynthetic capacity) can be predicted from simple qualitative plant characteristics, climate information, easily measured ("soft") leaf traits, or all of these in combination. The qualitative plant functional type (PFT) attributes examined are phylogeny (angiosperm or gymnosperm), growth form (grass, herb, shrub, or tree), and leaf phenology (deciduous vs. evergreen). These three PFT attributes explain between one-third and two-thirds of the variation in each of five quantitative leaf ecophysiological traits: specific leaf area (SLA), leaf life span, mass-based net photosynthetic capacity (Amass), nitrogen content (N(mass)), and phosphorus content (P(mass)). Alternatively, the combination of four simple, widely available climate metrics (mean annual temperature, mean annual precipitation, mean vapor pressure deficit, and solar irradiance) explain only 5-20% of the variation in those same five leaf traits. Adding the climate metrics to the qualitative PFTs as independent factors in the model increases explanatory power by 3-11% for the five traits. If a single easily measured leaf trait (SLA) is also included in the model along with qualitative plant traits and climate metrics, an additional 5-25% of the variation in the other four other leaf traits is explained, with the models accounting for 62%, 65%, 66%, and 73% of global variation in N(mass), P(mass), A(mass), and leaf life span, respectively. Given the wide availability of the summary climate data and qualitative PFT data used in these analyses, they could be used to explain roughly half of global variation in the less accessible leaf traits (A(mass), leaf life span, N(mass), P(mass)); this can be augmented to two-thirds of all variation if climatic and PFT data are used in combination with the readily measured trait SLA. This shows encouraging possibilities of progress in developing general predictive equations for macro-ecology, global scaling, and global modeling. 相似文献
308.
Alizée P. Lehoux Cindy L. Lockwood William M. Mayes Douglas I. Stewart Robert J. G. Mortimer Katalin Gruiz Ian T. Burke 《Environmental geochemistry and health》2013,35(5):643-656
Red mud is highly alkaline (pH 13), saline and can contain elevated concentrations of several potentially toxic elements (e.g. Al, As, Mo and V). Release of up to 1 million m3 of bauxite residue (red mud) suspension from the Ajka repository, western Hungary, caused large-scale contamination of downstream rivers and floodplains. There is now concern about the potential leaching of toxic metal(loid)s from the red mud as some have enhanced solubility at high pH. This study investigated the impact of red mud addition to three different Hungarian soils with respect to trace element solubility and soil geochemistry. The effectiveness of gypsum amendment for the rehabilitation of red mud-contaminated soils was also examined. Red mud addition to soils caused a pH increase, proportional to red mud addition, of up to 4 pH units (e.g. pH 7 → 11). Increasing red mud addition also led to significant increases in salinity, dissolved organic carbon and aqueous trace element concentrations. However, the response was highly soil specific and one of the soils tested buffered pH to around pH 8.5 even with the highest red mud loading tested (33 % w/w); experiments using this soil also had much lower aqueous Al, As and V concentrations. Gypsum addition to soil/red mud mixtures, even at relatively low concentrations (1 % w/w), was sufficient to buffer experimental pH to 7.5–8.5. This effect was attributed to the reaction of Ca2+ supplied by the gypsum with OH? and carbonate from the red mud to precipitate calcite. The lowered pH enhanced trace element sorption and largely inhibited the release of Al, As and V. Mo concentrations, however, were largely unaffected by gypsum induced pH buffering due to the greater solubility of Mo (as molybdate) at circumneutral pH. Gypsum addition also leads to significantly higher porewater salinities, and column experiments demonstrated that this increase in total dissolved solids persisted even after 25 pore volume replacements. Gypsum addition could therefore provide a cheaper alternative to recovery (dig and dump) for the treatment of red mud-affected soils. The observed inhibition of trace metal release within red mud-affected soils was relatively insensitive to either the percentage of red mud or gypsum present, making the treatment easy to apply. However, there is risk that over-application of gypsum could lead to detrimental long-term increases in soil salinity. 相似文献
309.
Judy S. LaKind Cheston M. Berlin Jr Jennifer L. Stokes Daniel Q. Naiman Ian M. Paul Donald G. Patterson Jr 《毒物与环境化学》2013,95(6):1047-1054
Polybrominated diphenyl ethers (PBDE) are a class of brominated flame retardants with some congeners having the ability to accumulate in body lipids. The incorporation of PBDE in consumer products found primarily in the indoor environment suggests that routes of exposure include inhalation of indoor air and contact with indoor dust. The purpose of this study was to test the hypothesis that lifestyle factors, and in particular the proximity and use of products likely to contain PBDE in the indoor environment, are primarily responsible for levels of PBDE found in human milk. Human milk samples were taken from two populations of lactating women in the same geographic region of the United States: one “typical” of US suburban lifestyle, and the other practicing a traditional Amish lifestyle, which excludes many modern amenities containing PBDE, such as computers and televisions. For a subset of the cohort, persistent organic pesticides and polychlorinated biphenyls (PCB) were also measured in human milk samples. Despite the small number of participants, there is evidence suggestive of Amish women having lower PBDE concentrations in their milk. In addition, the nonsignificant differences in levels of PCBs and pesticides between the two groups of women as compared to the significant differences in levels of PBDE suggest an important route of exposure for PBDE other than diet. Information prepared for study participants is provided to initiate a dialogue on how to best communicate biomonitoring findings to study participants and to the public in general. 相似文献
310.
Madhumita Mahalanabis Kelly A. Reynolds Ian L. Pepper Charles P. Gerba 《Food and environmental virology》2010,2(4):225-230
The goal of this study was to determine if a cytopathogenic effects (CPE) cell culture assay and an integrated cell culture
PCR (ICC-PCR) assay would yield similar or different results when used to assess virus survival in water. Poliovirus type
1 was added to dechlorinated tapwater and stored at room temperature (22.5–24°C) for a total of 50 days. Samples were assayed
at defined time intervals by the most probable number (MPN) method on Buffalo green monkey kidney cells (BGM) by CPE and additionally
by ICC-PCR. Monolayers that were CPE negative on first passage were passed onto fresh monolayers of cells for a second and
third time if still negative. By CPE assay, second passage was observed to yield a greater titer (2,300 vs. 24,000 MPN/ml)
and third passage also resulted in an increased titer. ICC-PCR proved to be a more rapid and sensitive method than conventional
cell culture for determining virus inactivation rates in water. Poliovirus survived in tapwater for up to 32 days, as assessed
by both third passage ICC-PCR and CPE. There was no statistical difference in the inactivation rates between the two methods.
To determine the total number of infectious viruses, these findings indicate the need for performing three cell culture passages
or, alternatively, ICC-PCR on first passage. 相似文献