全文获取类型
收费全文 | 223篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 9篇 |
环保管理 | 39篇 |
综合类 | 27篇 |
基础理论 | 44篇 |
污染及防治 | 72篇 |
评价与监测 | 20篇 |
社会与环境 | 11篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 13篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 17篇 |
2016年 | 7篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 20篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 11篇 |
2008年 | 14篇 |
2007年 | 12篇 |
2006年 | 15篇 |
2005年 | 3篇 |
2004年 | 10篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1983年 | 2篇 |
1958年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有232条查询结果,搜索用时 15 毫秒
41.
Decolorization of synthetic dyes by the Fenton reagent and the Cu/pyridine/H2O2 system 总被引:4,自引:0,他引:4
Representative azo, triphenylmethane, heterocyclic and polymeric synthetic dyes have been decolorized by two biological non-ezymatic systems, copper/pyridine/H2O2 and the Fenton reagent. With the former system, intensive decolorization measured after 1 h was obtained with phenol red (89%), tropaeolin 00 (58%), Evans blue (95%), eosin yellowish (84%), and Poly B-411 (92%). The rate of decolorization was not affected by pH in the range of 3-9 and increased with increasing temperature. The use of the radical scavengers thiourea and superoxide dismutase showed that hydroxyl radicals rather than superoxide anions are involved in the reaction. Omission of pyridine led to a substantial decrease in the extent of decolorization (20-50% decolorization). The use of organic peroxide instead of H2O2 resulted in slightly slower decolorization, similar values of decolorization being obtained only after a 2-h incubation. Decolorization of the dyes by the Fenton reagent was also very effective but slower than that obtained with the first system. Except for phenol red and eosin yellowish, (decolorization 8% and 52%, respectively) the dyes were decolorized up to 99% after 1-day incubation. 相似文献
42.
43.
Hua Shi Roger F. Auch James E. Vogelmann Min Feng Matthew Rigge Gabriel Senay James P. Verdin 《Journal of the American Water Resources Association》2018,54(2):505-526
While there are currently a number of irrigated land datasets available for the western United States (U.S.), there is uncertainty regarding in how they relate to each other. To help understand the characteristics of available irrigated datasets, we compared (1) the Cropland Data Layer (CDL), (2) Moderate Resolution Imaging Spectroradiometer Irrigated Agriculture Dataset (IAD), (3) Digitized Irrigated Land (DIL), and (4) Consumptive Use for Irrigation (CUI) data in Arizona and Colorado, U.S. These datasets were derived from multiple sources at various spatial resolutions and temporal scales. We found spatial and temporal trends among all of them. The datasets showed decreases in irrigated land area in Arizona during the 2000–2010 time period. The change ranges and ratios were similar in all Arizona datasets. Irrigated land in Colorado decreased in DIL and CUI but increased in IAD and CDL. The agreement within the same type of dataset during different time periods was from 60% to 80% (R2 from 0.35 to 0.72) in Arizona and from 50% to 80% (R2 from 0.23 to 0.68) in Colorado. DIL had the highest agreement (80%) in both states. The agreement among different datasets acquired at approximately the same time frame ranged from 51% to 63% (R2 from 0.14 to 0.31) in Arizona and from 47% to 69% (R2 from 0.32 to 0.40) in Colorado. The results from this study support a greater understanding of the multiresolution and multitemporal nature of these datasets for various applications. 相似文献
44.
Alice H. Tait David Raubenheimer Karen A. Stockin Monika Merriman Gabriel E. Machovsky-Capuska 《Marine Biology》2014,161(12):2791-2801
Foraging theory proposes that the nutritional driver of food choice and foraging in carnivores is energy gain. In contrast, recent laboratory experiments have shown that several species of carnivore select prey that provides a diet with a specific balance of macronutrients, rather than the highest energy content. It remains, however, to be determined how nutritionally variable the foods of predators in the wild are, and whether they feed selectively from available prey to balance their diet. Here, we used a geometric method named the right-angled mixture triangle (RMT) for examining nutritional variability in the prey and selected diets of a group of wild carnivores and marine top predators, the gannets (Morus spp.). A prey-level diet analysis was performed on Australasian gannets (M. serrator) from two New Zealand locations, and the macronutrient composition of their chosen prey species was measured. We use RMT to extend the comparison in the compositions of foods and diets from Australasian gannets from Australia as well as Northern gannets (M. bassanus) and Cape gannets (M. capensis). We found nutritional variability at multiple scales: intra- and interspecific variability in the pelagic fish and squid prey themselves; and intra- and interspecific variability in the diets consumed by geographically disparate populations of gannets. This nutritional variability potentially presents these predatory seabirds with both opportunity to select an optimal diet, and constraint if prevented from securing an optimal diet. 相似文献
45.
Gabriel Núñez-Antonio Manuel Mendoza Alberto Contreras-Cristán Eduardo Gutiérrez-Peña Eduardo Mendoza 《Environmental and Ecological Statistics》2018,25(4):471-494
The study of the interaction among species is an active area of research in Ecology. In particular, it is of interest to evaluate the overlap of their ecological niches. Temporal activity is one of the niche’s axes most commonly used to explore ecological segregation among animal species, and many contributions focus on the overlap of this variable. Once the information of the temporal activity is obtained in the wild, the data is treated as a random sample. There exist different methods to estimate the overlap. Specifically, in the case of two species, one possibility is to estimate the density of the temporal activity of each species and then evaluate the overlap between these density functions. This leads naturally to the analysis of circular data. Most of the procedures currently in use impose some rather restrictive assumptions on the probabilistic models used to describe the phenomena, and only provide approximate measures of the uncertainty involved in the process. In this article, we propose a Bayesian nonparametric approach which incorporates a well-defined noninformative prior. We take advantage of the data structure to define such a prior in terms of the predictive distribution. To the best of our knowledge, this is a novel approach. Our procedure is compared with a well-known method using simulated data, and applied to the analysis of real camera-trap data concerning two mammalian species from the El Triunfo biosphere reserve (Chiapas, Mexico). 相似文献
46.
Magnago Rachel Faverzani de Alcântara Braglia Thiago de Aguiar Ana Carolina Baungarten Polyana Mendonça Bruno Afonso Büchele Silva Heloisa Regina Turatti Egert Paola Girotto Edivandro Júnior Américo Cruz Parma Gabriel Oscar Cremona 《Journal of Material Cycles and Waste Management》2021,23(3):1126-1140
Journal of Material Cycles and Waste Management - This article aims to study the mechanical strength and fire resistance of polyurethane/cement (PuCem) composites containing glass sludge and sludge... 相似文献
47.
Stefan Gabriel 《International journal of occupational safety and ergonomics》2013,19(1):101-104
German employers ‘ liability insurance associations or Berufsgenossenschaften (BGs)—institutions for statutoryaccident insurance—maintain a measurement system for hazardous substances, the so-called BGMG. The aimof the BGMG is to determine and document valid results of measurements of exposure primarily for preventionpurposes. The data are collected systematically, in parallel to the sampling in a company. Parameters which aresupposed to have a visible effect on exposure levels are documented. The MEGA database (documentation ofmeasurement data relating to workplace exposure to hazardous substances) holds 1,629 million measurementvalues, which have been compiled in since 1972. The database offers a host of selection possibilities forassessments depending on the evaluation strategy. 相似文献
48.
Cristea Adorján Pustan Marius Bîrleanu Corina Dudescu Cristian Floare Călin Gabriel Tripon Andreea-Melisa Banciu Horia Leonard 《Journal of Polymers and the Environment》2022,30(1):424-430
Journal of Polymers and the Environment - Poly(3-hydroxybutyrate) (PHB) is a natural and biodegradable polyester which represents an alternative to replace conventional plastics in the packaging... 相似文献
49.