全文获取类型
收费全文 | 277篇 |
免费 | 4篇 |
国内免费 | 19篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 29篇 |
环保管理 | 24篇 |
综合类 | 59篇 |
基础理论 | 42篇 |
污染及防治 | 99篇 |
评价与监测 | 21篇 |
社会与环境 | 10篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 6篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 20篇 |
2012年 | 16篇 |
2011年 | 18篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 20篇 |
2007年 | 15篇 |
2006年 | 15篇 |
2005年 | 11篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1964年 | 1篇 |
1961年 | 1篇 |
1958年 | 2篇 |
排序方式: 共有300条查询结果,搜索用时 31 毫秒
271.
Kai-Lai G. Ho Anthony L. Pometto III Paul N. Hinz Arnoldo Gadea-Rivas Jorge A. Briceño Augusto Rojas 《Journal of Polymers and the Environment》1999,7(4):167-172
For use by the banana industry of Costa Rica, polylactic acid (PLA) plastic ropes and banana finger shrouds must remain operational for 14 to 16 weeks, and they also must be able to break down in the soil after serving their purposes. The banana field at La Rebusca Farm (Costa Rica) and the experiment station at University of Costa Rica were selected for a field exposure study of Cargill EcoPla Generation II (GII) and Cargill EcoPla monolayer (Ca-I) PLA films. The average monthly temperature, relative humidity, and cumulative rainfall of the La Rebusca Farm and the University of Costa Rica site were 26 and 22°C, 92 and 84%, and 352 and 177 in., respectively. The PLA plastic films at the La Rebusca Farm lost their mechanical properties earlier than at the University of Costa Rica site because of the higher temperature and relative humidity of the banana farm. The Ca-I film meets the 14-week operational time frame and it is recommended for further studies as ropes and banana shrouds. 相似文献
272.
Monumental features or landmarks in the urban built environment are distinguished by clear form, prominent location, a high degree of visibility and in Lefebvres (1991:143) words, "impose a clearly intelligible message". In Singapore, the gazetting and preservation of national monuments come under the ambit of the Preservation of Monuments Board. From the states perspective, national monuments embody historical value: as enduring landmarks of the city which link the present to the past, they give "lithic memory to the life of a nation" and are integral to the process of building national solidarity, identity and pride. This paper examines popular cognition of Singapores national monuments, that is, the extent to which the general public are able to identify gazetted monuments in visual and nomenclatural terms. A questionnaire survey of 284 respondents selected from a public housing estate as well as in-depth interviews with a smaller sample yielded information on Singaporeans visual recognition, nomenclatural accuracy and historical knowledge with respect to national monuments. The results showed that while visual identification of monuments was strong and the public could clearly identify the main attributes and general forms which national monuments take, the specific names of these monuments were often overlooked and historical knowledge of them rather shallow. In the conclusion, it is argued that if monuments are to serve their purpose as the countrys "psyche" annd "memory", deeper knowledge of the history and meaning behind these monuments must be inculcated in the Singaporean consciousness. 相似文献
273.
Wei-Eng Thung Soon-An Ong Li-Ngee Ho Yee-Shian Wong Fahmi Ridwan Yoong-Ling Oon Yoong-Sin Oon Harvinder Kaur Lehl 《环境科学学报(英文版)》2018,30(4):295-300
This study demonstrated the potential of single chamber up-flow membrane-less microbial fuel cell(UFML-MFC) in wastewater treatment and power generation. The purpose of this study was to evaluate and enhance the performance under different operational conditions which affect the chemical oxygen demand(COD) reduction and power generation,including the increase of KCl concentration(MFC1) and COD concentration(MFC2). The results showed that the increase of KCl concentration is an important factor in up-flow membrane-less MFC to enhance the ease of electron transfer from anode to cathode. The increase of COD concentration in MFC2 could led to the drop of voltage output due to the prompt of biofilm growth in MFC2 cathode which could increase the internal resistance. It also showed that the COD concentration is a vital issue in up-flow membrane-less MFC.Despite the COD reduction was up to 96%, the power output remained constrained. 相似文献
274.
ABSTRACT: This paper uses the grey fuzzy multiobjective programming to aid in decision making for the allocation of waste load in a river system under versatile uncertainties and risks. It differs from previous studies by considering a multicriteria objective function with combined grey and fuzzy messages under a cost benefit analysis framework. Such analysis technically integrates the prior information of water quality models, water quality standards, wastewater treatment costs, and potential benefits gained via in‐stream water quality improvement. While fuzzy sets are characterized based on semantic and cognitive vagueness in decision making, grey numbers can delineate measurement errors in data collection. By employing three distinct set theoretic fuzzy operators, the synergy of grey and fuzzy implications may smoothly characterize the prescribed management complexity. With the aid of genetic algorithm in the solution procedure, the modeling outputs contribute to the development of an effective waste load allocation and reduction scheme for tributaries in this subwatershed located in the lower Tseng‐Wen River Basin, South Taiwan. Research findings indicate that the inclusion of three fuzzy set theoretic operators in decision analysis may delineate different tradeoffs in decision making due to varying changes, transformations, and movements of waste load in association with land use pattern within the watershed. 相似文献
275.
Sensitivity analysis of ground-level ozone concentration to emission changes in two urban regions of southeast Texas 总被引:1,自引:0,他引:1
Lin CJ Ho TC Chu HW Yang H Chandru S Krishnarajanagar N Chiou P Hopper JR 《Journal of environmental management》2005,75(4):315-323
Air pollutant emission is one of the predominant factors affecting urban air quality such as ground-level ozone formation. This paper assesses the impact of changing emission inventory scenarios, based on combinations of point, mobile, area/non-road and biogenic sources, on the tropospheric ozone concentration in two southeast Texas urban areas, i.e. Houston-Galveston and Beaumont-Port Arthur, during the rapid ozone formation event (ROFE) on August 25, 2000. The EPA's Community Multiscale Air Quality (CMAQ) modeling system with 1999 national emission inventory (NEI99) estimates and updated SAPRC99 chemical mechanism are used in the sensitivity analysis for twelve different emission scenarios. Based on model results, it is found that the point source emission of NOx and VOC contributes the greatest ozone peak in the ROFE. Removing Texas point sources of VOC and NOx emission from the inventory results in a reduction in peak O3 concentration by 128 and 70 ppbv in Houston urban area, respectively. Similar but less drastic impact from point source is also observed in the Beaumont-Port Arthur area. The effect on peak ozone concentration due to mobile, area and non-road sources emissions are less significant compared to that of point source emission. Reducing VOC emission appears to be more effective than reducing NOx emission in lowering peak O3 concentration in the studied region. Although biogenic emission can contribute up to 37 ppbv of peak ozone level over a large area, the affected area is away from the urban region of concern, and should not be the main cause for O3 non-attainment in the two urban areas. Removing CO emission from mobile sources does not lead to significant reduction (< 1 ppbv) in ozone concentrations. The modeled data also show that the transport of O3 precursors from adjacent states can cause a significant ozone plume near Beaumont due to its proximity to the state border based on the conditions during the August 25, 2000 O3 episode. 相似文献
276.
Sang Hwa Jin Yeong-Koo Yeo Kwang Ho Song In-Won Kim 《Journal of Loss Prevention in the Process Industries》2002,15(6):439-444
Although reliability analyses have been used to improve the reliability of industrial systems, generic reliability data from publications, such as component failure intensities and repair times, are used to calculate reliability measures instead of the real reliability data collected from the plant. One reason is that the repair history of the components is not well managed in the plant. In this work, the effect of extreme reliability parameter values on system reliability and unavailability is studied. To do this, importance and uncertainty analysis of the components of flue gas scrubber systems is carried out, and results calculated with the extreme reliability parameter values are compared with those with the mean reliability values of the systems. The different reliability parameter values can give us totally different ranks of the components critical to the reliability of the representative scrubber system. Consequently, the effort to establish a reliable database is emphasized to perform accurate reliability analysis of the system. 相似文献
277.
Landfill and sea-dumping appear to be on their way out as acceptable methods for the disposal of untreated industrial wastes in Taiwan. Recently, there has been interest in the application of fluidized bed technology to waste incineration for efficient energy utilization and environmental protection. A pilot fluidized bed combustion system was used to investigate the incineration performance and parametric test for the waste from an industrial park. According to the experimental results, the appropriate operating conditions, including temperatures of 800-840 degrees C, aeration rates of U(0)/Um(f)-2.0 or so, and on-bed feeding, were recommended to treat such waste. The emissions of SO(x), NO(x) and CO in flue gas meet the ROC-EPA regulation. 相似文献
278.
279.
280.
Paul Chiou Wei Tang Che-Jen Lin Hsing-Wei Chu Rafael Tadmor T. C. Ho 《Environmental Modeling and Assessment》2009,14(5):645-659
Speciated samples of PM2.5 were collected at the Big Bend site from July of 2003 to June 2006 and the McDonald Observatory site from July of 2003 to
August of 2005 in southwestern Texas, respectively, by the US Environmental Protection Agency. A total of 175 samples for
the Big Bend site and 105 samples for the McDonald Observatory site with 52 species were measured; however, 30 and 32 species
from the Big Bend and McDonald Observatory sites, respectively, were excluded because of too much below-detection-limit data.
Due to the laboratory change about November 1 of 2004 and possible analytical artifacts, phosphorous was excluded as well.
Among the species excluded, 31 species are common to both sites. The two data sets were analyzed by positive matrix factorization
to infer the sources of PM observed at the two sites. The analysis resolved five source-related factors for Big Bend and four
for McDonald Observatory. Sulfate-rich secondary aerosol, coal burning, motor vehicle/road dust, and a mixed factor were identified
as common sources to both sites. The other factor identified for Big Bend is related to soil. Sulfate mainly exists as ammonium
salts. The sulfate-rich secondary aerosols account for about 62% and 66% of the PM2.5 mass concentration at the two sites, respectively. The highest concentration of Si associated with Ca, Fe,
\textSO42 - {\text{SO}}_4^{2 - } , and organic carbon at the two sites was possibly attributed to the coal-fired power plants in the region. Basically, the
factor of sulfate and coal burning at the two sites showed similar chemical composition profiles and seasonal variation that
reflect the regional characteristics of these sources. The regional factors of sulfate, coal burning, and soil showed predominantly
low-frequency variations; however, the area-related and/or local factors showed both high and low frequency variations. The
motor vehicle/road dust and the mixed factors were likely to be area-related and/or local source. 相似文献