全文获取类型
收费全文 | 65篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
废物处理 | 11篇 |
环保管理 | 8篇 |
综合类 | 12篇 |
基础理论 | 6篇 |
污染及防治 | 25篇 |
评价与监测 | 4篇 |
社会与环境 | 1篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 5篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1958年 | 2篇 |
1932年 | 1篇 |
排序方式: 共有67条查询结果,搜索用时 78 毫秒
41.
42.
43.
44.
The omnivorous sea urchin Strongylocentrotus pulcherrimus inhabits the coast of Japan. It also ingests foreign foods, which are not normally present in the natural habitat. In cultures, foreign foods, such as white fish meal, shellfish meal, milk casein, gelatin, soybean meal, yellow corn, alfalfa and yeast were provided in the form of a moist and soft material and their ingestion and digestibility were examined. The foreign foods were prepared by mixing with agar-agar. Digestibility of the diet, and that of nitrogen contained in the diet, was estimated as 54.7 and 64.7% dry weight. Sea urchins cultivated over a period of 5 months on such a foreign diet exhibited 24% increase in wet weight during this period. Occasionally, the ingestion of artificial food suddenly decreased, but was soon resumed upon supplying a hot-water extract of brown algae. 相似文献
45.
Kim DS Harazono Y Baten MA Nagai H Tsuruta H 《Journal of the Air & Waste Management Association (1995)》2002,52(4):416-422
The CO2 and N2O soil emissions at a rice paddy in Mase, Japan, were measured by enclosures during a fallow winter season. The Mase site, one of the AsiaFlux Network sites in Japan, has been monitored for moisture, heat, and CO2 fluxes since August 1999. The paddy soil was found to be a source of both CO2 and N2O flux from this experiment. The CO2 and N2O fluxes ranged from -27.6 to 160.4 microg CO2/m2/sec (average of 49.1 +/- 42.7 microg CO2/m2/sec) and from -4.4 to 129.5 ng N2O/m2/sec (average of 40.3 +/- 35.6 ng N2O/m2/ sec), respectively. A bimodal trend, which has a sub-peak in the morning around 10:00 a.m. and a primary peak between 2:00 and 3:00 p.m., was observed. Gas fluxes increased with soil temperature, but this temperature dependency seemed to occur only on the calm days. Average CO2 and N2O fluxes were 27.7 microg CO2/m2/sec and 13.4 ng N2O/m2/sec, with relatively small fluctuation during windy days, while averages of 69.3 microg CO2/m2/sec and 65.8 ng N2O/m2/sec were measured during calm days. This relationship was thought to be a result of strong surface winds, which enhance gas exchange between the soil surface and the atmosphere, thus reducing the gas emissions from soil surfaces. 相似文献
46.
47.
Masahide Aikawa Toshimasa Ohara Takatoshi Hiraki Okihiro Oishi Akihiro Tsuji Makiko Yamagami Kentaro Murano Hitoshi Mukai 《Atmospheric environment (Oxford, England : 1994)》2010,44(3):381-391
We found a significant geographic gradient (longitudinal and latitudinal) in the sulfate (SO42?) concentrations measured at multiple sites over the East Asian Pacific Rim region. Furthermore, the observed gradient was well reproduced by a regional chemical transport model. The observed and modeled SO42? concentrations were higher at the sites closer to the Asian continent. The concentrations of SO42? from China as calculated by the model also showed the fundamental features of the longitudinal/latitudinal gradient. The proportional contribution of Chinese SO42? to the total in Japan throughout the year was above 50–70% in the control case, using data for Chinese sulfur dioxide (SO2) emission from the Regional Emission Inventory in Asia (40–60% in the low Chinese emissions case, using Chinese SO2 emissions data from the State Environmental Protection Administration of China), with a winter maximum of approximately 65–80%, although the actual concentrations of SO42? from China were highest in summer. The multiple-site measurements and the model analysis strongly suggest that the SO42? concentrations in Japan were influenced by the outflow from the Asian continent, and this influence was greatest in the areas closer to the Asian continent. In contrast, we found no longitudinal/latitudinal gradient in SO2 concentrations; instead SO2 concentrations were significantly correlated with local SO2 emissions. Our results show that large amounts of particulate sulfate are transported over long distances from the East Asian Pacific Rim region, and consequently the SO42? concentrations in Japan are controlled by the transboundary outflow from the Asian continent. 相似文献
48.
49.
50.
Adsorption of 2,4-dichlorophenoxyacetic acid by an Andosol 总被引:1,自引:0,他引:1
To identify the important soil components involved in 2,4-dichlorophenoxyacetic acid (2,4-D) adsorption on Andosols, 2,4-D adsorption on a surface horizon of an Andosol was compared with that on hydrogen peroxide (H2O2)-treated (soil organic matter [SOM] was removed), acid-oxalate (OX)-treated (active metal hydroxides and SOM were removed), and dithionite-citrate-bicarbonate (DCB)-treated (free and active metal [hydr]oxides and SOM were removed) soil samples at equilibrium pHs ranging from 4 to 8. Although the untreated soil contained a large amount of organic C (71.9 g kg-1), removal of SOM had little effect on 2,4-D adsorption. Active surface hydroxyls, which were attached to the active and free metal (hydr)oxides and metal SOM complexes, were identified as the most important soil functional group for 2,4-D adsorption. The dominant mechanism of the 2,4-D adsorption was a ligand exchange reaction in which the carboxylic group of 2,4-D displaced the active surface hydroxyl associated with metals and formed a strong coordination bond between the 2,4-D molecule and soil solid phase. The ligand exchange reaction reasonably accounted for the selective adsorption of 2,4-D over Cl-, competitive adsorption of phosphate over 2,4-D, reduction in plant-growth-inhibitory activity of soil-adsorbed 2,4-D, and the high 2,4-D adsorption ability of Andosols. Although a humic acid purified from the soil did not adsorb 2,4-D, the presence of the humic acid increased 2,4-D adsorption on Al and Fe, probably by inhibiting the hydrolysis and polymerization of Al and Fe resulting in the preservation of available adsorption sites on these metals. The adsorption behavior of 2,4-D on soils could be a good index for predicting the adsorption behavior of other organic acids in soils. 相似文献