首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   694篇
  免费   21篇
  国内免费   192篇
安全科学   49篇
废物处理   38篇
环保管理   38篇
综合类   288篇
基础理论   113篇
污染及防治   303篇
评价与监测   33篇
社会与环境   24篇
灾害及防治   21篇
  2023年   10篇
  2022年   38篇
  2021年   19篇
  2020年   22篇
  2019年   14篇
  2018年   27篇
  2017年   33篇
  2016年   34篇
  2015年   34篇
  2014年   48篇
  2013年   75篇
  2012年   54篇
  2011年   58篇
  2010年   39篇
  2009年   32篇
  2008年   43篇
  2007年   34篇
  2006年   38篇
  2005年   27篇
  2004年   21篇
  2003年   36篇
  2002年   16篇
  2001年   19篇
  2000年   21篇
  1999年   17篇
  1998年   15篇
  1997年   12篇
  1996年   11篇
  1995年   19篇
  1994年   11篇
  1993年   8篇
  1992年   7篇
  1991年   7篇
  1990年   2篇
  1989年   2篇
  1985年   3篇
  1975年   1篇
排序方式: 共有907条查询结果,搜索用时 15 毫秒
171.
基于超临界水氧化过程的能源环境系统设计   总被引:2,自引:0,他引:2  
阐述了超临界水氧化过程的工艺路线,介绍了超临界水氧化过程的特点,提出了基于超临界水氧化过程的能源环境系统,设计了几种热量与能量回收系统程的耦合工艺,为提高超临界水氧化过程的经济性奠定了基础。  相似文献   
172.
Yu-Hern Chang  Meng-Yuan Liao   《Safety Science》2009,47(10):1337-1345
This paper examines the effect of aviation safety education on passenger cabin safety awareness in knowledge, attitude, and behavior (KAB). The educational value of KAB has been addressed in various fields such as AIDS prevention and campus safety. KAB has been applied in aviation safety related areas, especially in training, such as crew resource management training, pilot training, and mechanic training. However, KAB has not been implemented in aviation passenger education in cabin safety. This paper uses the construct of “aviation safety education”, which is intended to influence airline passenger knowledge of, attitude toward, and behavior about cabin safety awareness. Passenger surveys were done at two Taiwan airports. The results show that aviation safety education positively affects airline passenger cabin safety knowledge, attitude, and behavior. We recommend safety education that involves accurate instruction about emergency equipment procedures, situational awareness, emergency responses, and relevant cabin-safety regulations.Our findings indicated that an increase in cabin safety knowledge positively affected airline passenger behavior, which supported knowledge–behavior consistency. We also found that a positive attitude toward cabin safety positively affected airline passenger behavior, which supported attitude–behavior consistency. The hypothesis that cabin safety knowledge positively affected passenger attitude – knowledge–attitude consistency was not supported.  相似文献   
173.
This article reports on soil samples collected from Hsiang-Shan wetland, Taiwan. Canonical discriminant analysis (CDA) was applied to identify an existing habitat type's scheme by identifying the physico-chemical properties of sediment in Hsiang-Shan wetland. The three constructed discriminant functions (CDFs) showed a marked contribution by most of the discriminant variables, and the recognition capacities in these three CDFs were 49.5, 32.8 and 17.7%. Our study revealed that the most important latent factors in Hsiang-Shan wetland are soil texture-caused factor, ocean current-caused factor, nutrient-caused factor, and the redox reaction-caused factor. And the most sensitivity parameters in this habitat followed the descending order: OBD, EC, Eh, sand, TN, porosity, STP, silt, VCP and pH. And the inhabited sediment properties for U. formosensis in terms of soil texture are sand, silt, and clay (34.05, 29.72, and 32.35%, respectively): that is clay loam soil. We also found that U. formosensis preferred to inhabit the upper intertidal zone, spending 8.41% of the time submerged. Vegetation coverage on the ground was less than 2.20%, showing that it preferred to live in a bare intertidal habitat. Concerning nest choosing, excavating burrows is more difficult when a high soil penetration force is required, and in this study the soil penetration force for 20 cm was found to be is 45.98 N/cm(2). The results will be helpful in developing a methodology for use by the government in refining its management programs.  相似文献   
174.
Freshwater clam Corbicula fluminea, a surrogate species in metal toxicity testing, is a promising bioindicator of impairment in aquatic ecosystems. Little is known, however, about the relationship between clam valve daily rhythmic response and metal bioavailability related to a metal biological early warning system (BEWS) design. The purpose of this study was to link biotic ligand model (BLM)-based bioavailability and valve daily rhythm in C. fluminea to design a biomonitoring system for online in situ detection of waterborne copper (Cu). We integrated the Hill-based dose-time-response function and the fitted daily rhythm function of valve closure into a constructed programmatic mechanism. The functional presentation of the present dynamic system was completely demonstrated by employing a LabVIEW graphic control program in a personal computer. We used site-specific effect concentration causing 10% of total valve closure response (EC10) as the detection threshold to implement the proposed C. fluminea-based Cu BEWS. Here our results show that the proposed C. fluminea-based BEWS could be deliberately synthesized to online in situ transmit rapidly the information on waterborne bioavailable Cu levels under various aquatic environmental conditions through monitoring the valve daily rhythmic changes. We suggested that the developed C. fluminea-based dynamic biomonitoring system could assist in developing technically defensible site-specific water quality criteria to promote more efficient uses in water resources for protection of species health in aquatic environments.  相似文献   
175.
A mixed-integer programming model that minimizes the social abatement cost is used to investigate whether a market equilibrium condition could be reached in a newly proposed permit-trading market for nitrogen oxide control in Taiwan. Unlike in previous studies, unit pollution abatement cost is determined endogenously by incorporating technology adoption as a binary decision variable. The results show that when technologies are lumpy and irreversible, disequilibrium might occur due to firms’ inability to manage their emission levels after installing equipment with fixed size and control capacity.
Chao-ning LiaoEmail:
  相似文献   
176.
Huang SS  Liao QL  Hua M  Wu XM  Bi KS  Yan CY  Chen B  Zhang XY 《Chemosphere》2007,67(11):2148-2155
We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.  相似文献   
177.
Modeling VOC-odor exposure risk in livestock buildings   总被引:1,自引:0,他引:1  
Liang HM  Liao CM 《Chemosphere》2007,68(4):781-789
This paper describes a novel idea of linking models of exposure, internal dosimetry, and health effects. Risk assessment approach that integrates predicted odor caused by volatile organic compounds (VOC-odor) of toluene/xylene concentrations in human tissues leads to predict exposure risks in livestock buildings. First, VOC transport model was developed to calculate airborne toluene/xylene concentrations. Based on a physiologically based pharmacokinetic (PBPK) model, concentrations within five compartments representing lung, liver, fat, slowly perfused tissues, and rapidly perfused tissues could be quantified. By using a pharmacodynamic (PD) Hill model, we can optimally fit data from rat and human experiments to reconstruct dose-response relationships for accounting human health effects from nose poke and eye irritation. Results demonstrated that peak tissue concentration occurring at 5-10h in that fat contains the highest concentration than other tissues at around 4ppm of toluene and 1.8ppm of xylene. The EC(10) values are 114 and 232ppm, whereas expected risks are estimated to be 0.71% and 0.26% of human exposure to toluene and xylene, respectively. Risk analyses indicate that inhalation exposure in livestock buildings poses no significant threat to human health under the present environmental conditions. This method provides a rigorous and effective approach to relate target tissue concentration to human nose poke or eye irritation. We suggest that our probabilistic framework and methods be taken seriously because they produce general conclusions that are more robust and could offer a risk-management framework for discussion of future establishment of limits for respiratory exposure to VOC-odor.  相似文献   
178.
A full-scale sequencing batch reactor (SBR) system was evaluated for its ability to remove carbon and nitrogen from swine wastewater. The SBR was operated on four, six-hour cycles each day, with each cycle consisting of 4.5 hours of "React," 0.75 hours of "Settling", 0.75 hours for "Draw" and "Fill." Within each cycle, an amount of wastewater equivalent to about 5% of the reactor volume (5,500 litres) was removed and added. The SBR system was able to remove 82% of biochemical oxygen demand (BOD) and more than 75% of nitrogen. Even though the SBR effluent, with an average effluent BOD5 of about 588 mg L(-1), did not meet the discharge criteria, it enabled a reduction of the land base required for land application of swine wastewater by about 75%. Results indicated that the SBR system was a viable method for the treatment of swine wastewater.  相似文献   
179.
在回顾国内外策划发展史的基础上,提出了璧山县旅游产品策划的概念;结合璧山县旅游产品策划的背景,提出璧山县旅游产品策划的原则,重点对新资源古特色、新功能、全面整合等旅游产品策划方式进行了研究。通过挖掘璧山县旅游资源特色及文化内涵,提出了璧山县旅游产品策划的几个方向。  相似文献   
180.
Studies on the distribution and isotope compositions of fallout Pu are important for source characterization of possible future non-fallout Pu contamination in aquatic environments, and useful for dating of recent sediments to understand the pollution history of environmental contaminants. We present the historical record of atmospheric Pu fallout reconstructed from a sediment core from Lake Hongfeng, China. The Pu activity profile was in agreement with the 137Cs profile. Inventories were 50.7 Bq m(-2) for 239+240Pu and 1586 Bq m(-2) for 137Cs. The average 240Pu/239Pu atom ratio was 0.185+/-0.009, indicating that Pu originated from global stratospheric fallout rather than from direct tropospheric or close-in fallout from the Chinese nuclear testing conducted in the 1970s. Our data suggested that Lake Hongfeng would be an ideal setting for monitoring atmospheric fallout and environmental changes in this region.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号