全文获取类型
收费全文 | 1445篇 |
免费 | 269篇 |
国内免费 | 549篇 |
专业分类
安全科学 | 208篇 |
废物处理 | 56篇 |
环保管理 | 119篇 |
综合类 | 1201篇 |
基础理论 | 205篇 |
污染及防治 | 226篇 |
评价与监测 | 100篇 |
社会与环境 | 78篇 |
灾害及防治 | 70篇 |
出版年
2024年 | 15篇 |
2023年 | 63篇 |
2022年 | 147篇 |
2021年 | 109篇 |
2020年 | 131篇 |
2019年 | 104篇 |
2018年 | 118篇 |
2017年 | 124篇 |
2016年 | 108篇 |
2015年 | 122篇 |
2014年 | 111篇 |
2013年 | 153篇 |
2012年 | 132篇 |
2011年 | 137篇 |
2010年 | 108篇 |
2009年 | 84篇 |
2008年 | 76篇 |
2007年 | 78篇 |
2006年 | 81篇 |
2005年 | 52篇 |
2004年 | 41篇 |
2003年 | 24篇 |
2002年 | 32篇 |
2001年 | 37篇 |
2000年 | 21篇 |
1999年 | 14篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
排序方式: 共有2263条查询结果,搜索用时 15 毫秒
971.
For making rational and scientific land-use planning,an inventory indicator of land productivity subject to biophysical limitations and human disturbance is required.This study introduces agricultural land productivity(ALP)as the dynamic indicator to measure land productivity,involving factors that affect agricultural production,such as characteristics of climate,soil,and terrain.As a case study of this dynamic indicator,ALP was estimated at county level and aggregated into provincial level in the whole of China.The result shows that ALP increased during 2000-2010 in China,and the ratios of ALP to the actual grain yield were 65.40%and 66.38%in the years 2000 and 2005,respectively.The ALP is an effective dynamic indicator to estimate the land productivity and to represent the basic conditions about the supply of water,energy,nutrients,and the physical basis for plant growth,as well as the local input.ALP estimation could provide supporting information for policy-making about land production planning and land-use management. 相似文献
972.
运用生命周期评价方法,对以天然气为原料生产压缩天然气、甲醇、二甲醚、柴油4种汽车代用燃料系统进行生命周期的能源、环境和经济评价,评价结果是:压缩天然气系统生命周期内的能耗相对少,总成本相对低,对生态环境更友好,压缩天然气是富含天然气地区一段时期内汽车代用燃料的优先选择. 相似文献
973.
余小萱负重践行"绿色奥运" 总被引:1,自引:0,他引:1
记者在约定的时间来到奥组委环境部所在的青蓝大厦,余小萱部长已在办公室走廊里笑迎。这位1974年即投身环保工作,曾任北京市环保局副局长10余年的奥组委官员,虽然讲话慢条斯理,可身负的责任和压力却绝不轻松——随着明年初都灵冬奥会的结束,世界投向北京的目光将越来越多、越来越挑剔,北京自申奥伊始即提出的“绿色奥运”能否兑现,自然倍受关注。[编者按] 相似文献
974.
本文在利用EXCEL制作控制图方面进行了初步尝试。以该方法制作控制图快速、准确、易于推广,是环境监测工作中质量控制的有效手段。 相似文献
975.
Feng Rui Wang Qing Huang Cheng-chen Liang Jin Luo Kun Fan Jian-ren Zheng Hui-jun 《Environmental Chemistry Letters》2019,17(2):1151-1160
Environmental Chemistry Letters - The occurrence of volatile organic compounds (VOCs) in the atmosphere is a major health issue, notably in China, because those compounds are the precursors of... 相似文献
976.
Jun Wang Jia Li Yingpeng Xie Chengwu Li Guangxi Han Liquan Zhang Rui Xu Xiangdong Zhang 《Journal of environmental management》2010,91(3):677-684
In this work, Er3+:YAlO3/ZnO–TiO2 and ZnO–TiO2 composites were prepared by the ultrasonic dispersion and liquid boiling method. In succession, they were then characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Acid red B as a model dye compound was degraded under solar light irradiation to evaluate the photocatalytic activities of the Er3+:YAlO3/ZnO–TiO2 and ZnO–TiO2 composites. We found that the photocatalytic activity of ZnO–TiO2 composite can be enhanced by adding an appropriate amount of Er3+:YAlO3. We reviewed influencing factors, such as Er3+:YAlO3 content, heat-treated temperature and heat-treated time on the photocatalytic activity of the Er3+:YAlO3/ZnO–TiO2 composites. In addition, the effects of solar light irradiation time, dye initial concentration, Er3+:YAlO3/ZnO–TiO2 amount and solution acidity on the photocatalytic degradation of acid red B dye in aqueous solution were investigated in detail. Simultaneously, the degradation and comparison of other dyes such as methyl orange (MO), rhodamine B (RM-B), azo fuchsine (AF), congo red (CG-R) and methyl blue (MB) were also reviewed. In addition, we attempted to explore both the principle of possible excitation of Er3+:YAlO3/ZnO–TiO2 under solar light irradiation and the mechanism of photocatalytic degradation. 相似文献
977.
Rui Yang Rong-Yi Zhao 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1516-1524
Abstract An improved photocatalytic oxidation (PCO) reactor model was developed to analyze the removal of volatile organic compounds (VOCs) in indoor air. One new parameter, the average total removing factor K t, together with the other two parameters, the number of mass transfer units NTUm and the fractional conversion e, are found to be the main parameters influencing the photooxidation performance of PCO reactors. Three new parameters, the ideal reaction number of mass transfer units, NTUm,ir; the ideal reaction fractional conversion, εir; and the reaction effectiveness, η, also are defined. These concepts are helpful to the structural design and optimization for PCO reactors. The application of the model in designing a plate-type PCO reactor is demonstrated. This study shows that the present model is an effective tool for designing PCO reactors and for evaluating VOC removal performance of available PCO reactors. 相似文献
978.
Mónica A. Silva Rui Prieto Sara Magalh?es Maria I. Seabra Ricardo S. Santos Philip S. Hammond 《Marine Biology》2009,156(2):179-192
Very little is known about the ecology of common bottlenose dolphins (Tursiops truncatus) living in oceanic waters. This study investigated the ranging and residence patterns of bottlenose dolphins occurring in
the Azores (Portugal), the most isolated archipelago in the North Atlantic. Data were collected during standardized boat-based
surveys conducted over a 6-year period in an area of approximately 5,400 km2 (main study area). To investigate the extent of movements of individual animals, non-systematic surveys were also conducted
outside this area. Only 44 individuals out of 966 identified were frequently sighted within and between years. The remaining
individuals were either temporary migrants from within or outside the archipelago, or transients. Resident dolphins showed
strong geographic fidelity to the area. Long-distance movements (of almost 300 km), consistent with foraging or exploratory
trips, were observed among non-resident dolphins. Home range size was estimated for 31 individuals sighted ≥10 times. Range
areas of these dolphins varied in size and location, but considerable overlap was observed in the areas used, suggesting the
absence of habitat partitioning between resident and non-resident dolphins. Estimates of home range size of bottlenose dolphins
in the Azores were found to be considerably larger than those previously reported for this species. It is hypothesized that
dolphins living in the Azores carry out extensive movements and have large home ranges in response to the lower density and
patchy distribution of prey compared to other areas. The extensive ranging behaviour and the lack of territoriality provide
an opportunity for interbreeding between dolphins associated with different islands, thus preventing genetic differentiation
within the population of the Azores. 相似文献
979.
980.
Yong H. Qi Hui C. Zhang Rui T. Xu Jin Liu Lei Zhang 《Journal of environmental science and health. Part. B》2013,48(9):645-653
The objective of the present study was to develop a multi-analyte immunoassay for the determination of eight red dyes in food samples. Two dye intermediates (2-hydroxy-1-naphthoic acid and 1-amino-2-naphthol) were used as the haptens to produce the monoclonal antibodies. The obtained monoclonal antibodies recognized Sudan 1–4, Para red, Sudan red G, Sudan red B and Acid orange II simultaneously. After evaluation of different antibody/coating antigen combinations, a heterologous indirect competitive enzyme linked immunosorbent assay was developed to determine the eight red dyes in food samples (chili oil, chili powder, tomato sauce, hotpot seasoning). The crossreactivities to the eight analytes were in the range of 61%–79% (with β-naphthol as 100%), and the limits of detection were in the range of 1.3–1.9 ng/mL. The recoveries of the eight analytes from the fortified blank samples were in the range of 84.2%–115% with coefficients of variation lower than 18.3%. Therefore, this method could be used as a rapid and simple tool to detect the residues of the eight red dyes in foods. 相似文献