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291.
研究了2,4,6-三氯酚(TCP)在水中不同存在形态、水体pH值、溶解氧、藻类对其光化学降解行为的影响。先用孔雀绿无色氰化物(MGLC),计算天津海河、北排污河两个自然水体,底泥悬浮物引起的光分散衰减系数,再用RG.Zeep公式预测出天津海河水中TCP的光解速率高于天津北排污河。天津污水土地处理系统进口水中TCP的光解速率常数:在夏季,kd=0.059(h-1);在冬季kd=0.011(b-1);光解半衰期为19.8h-1。实验结果为处理后污水的安全回用提供了科学依据。 相似文献
292.
通过对海南岛上万名学龄前儿童头发钙含量以及所处地域农耕旱地土壤交换性钙的调查与分析发现:土壤钙与儿童头发钙含量呈极显著正相关;海南岛儿童头发钙均值低于国内其它地方的报道值;土壤环境钙含量的高低,能间接反映人体钙的营养状况。 相似文献
293.
Sea-level rise and coastal vulnerability: an assessment of Andhra Pradesh coast,India through remote sensing and GIS 总被引:2,自引:1,他引:1
K. Nageswara Rao P. Subraelu T. Venkateswara Rao B. Hema Malini R. Ratheesh S. Bhattacharya A. S. Rajawat Ajai 《Journal of Coastal Conservation》2008,12(4):195-207
The eustatic sea-level rise due to global warming is predicted to be about 18 to 59 cm by the 2100 (IPCC 2007), which necessitates identification and protection of vulnerable sections of coasts. Assessment of vulnerability level of
Andhra Pradesh (AP) coast as an example is demonstrated in this study using five physical variables, namely coastal geomorphology,
coastal slope, shoreline change, mean spring tide range, and significant wave height. A coastal vulnerability index was prepared
by integrating the differentially weighted rank values of the five variables, based on which the coastline is segmented into
low-, moderate-, high-, and very high risk categories. About 43% of the 1,030-km-long AP coast is under very high-risk, followed
by another 35% under high-risk if the sea level rises by ~0.6 m displacing more than 1.29 million people living within 2.0 m
elevation in 282 villages in the region. 相似文献
294.
Ramaneswari K Rao LM 《Journal of environmental biology / Academy of Environmental Biology, India》2008,29(2):183-185
The response of NADPH cytochrome C reductase (NCCR) activity in liver of Labeo rohita fish exposed to the pesticides, 0.25 microgl(-1) endosulfan and 2 mg/l monocrotophos was studied. In terms of specific enzyme activity (mU/mg protein) a significant level of NCCR was observed in the liver tissues of Labeo rohita exposed to the pesticides, when compared to the control fish (2.460 mU/mg protein). Increase of NCCR activity was more in the liver of the fish exposed to monocrotophos (4.595 mU/mg protein) than those exposed to endosulfan (2.850 mU/mg protein). The results demonstrate that the pesticides, endosulfan and monocrotophos, interfere with NADPH dependent monoxygenase mechanism and are effective inducers of NADPH cytochrome C reductase. The activity of NCCR in the liver tissue of Labeo rohita may serve as a useful tool for monitoring aquatic pollution. 相似文献
295.
In the course of their foraging bouts, bees frequently encounter spider webs among the vegetation. The ability to see and
avoid these webs is vital for the success of the individual bee’s foraging bout. In this study, we report on the response
of stingless bees (Trigona carbonaria) towards the webs of the St. Andrew’s Cross spider (Argiope keyserlingi). We studied the ability of bees to avoid webs in different contexts: when bees were on their foraging path or when they
were returning to the hive as well as when they were flying North or South. We show that the probability of a bee being able
to avoid a web depends on the context of the bee’s flight rather than the visual appearance of the web. Furthermore, the presence
of the spider seems to alert the bee to the web, resulting in bees being more able to avoid capture. We show, specifically,
that the probability of being captured is higher when the bee is returning to the hive compared with when the bee is foraging.
The likelihood of avoiding a web is also influenced by the compass direction of the flight, although to a lesser extent. Our
results indicate that the context of the predator–prey encounter has a significant influence on a bee’s ability to escape
interception by a spider web. 相似文献
296.
Madhavi D Devil KR Rao KK Reddy PP 《Journal of environmental biology / Academy of Environmental Biology, India》2007,28(1):115-117
The objective of the present study was to evaluate the protective effect of Phyllanthus emblica against clastogenicity induced by lead nitrate on the incidence of sperm head abnormalities in the germ cells of mice. At higher concentration of lead, a significant increase in the percentage of sperm head abnormalities was noted but when animals primed with Phyllanthus fruit extract (PFE), a reduction in the frequency of sperm head abnormalities was observed. It can be suggested from the above study that Phyllanthus emblica plays a key role in inhibition of heavy metal mutagenesis in mammals. 相似文献
297.
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299.
采用共沉淀法制备了复合光催化剂Fe_3O_4-xTiO_2。运用XRD、SEM、TEM和UV-Vis DRS等技术对光催化剂进行了表征,并考察了其在太阳光下对茜素红模拟染料废水的光催化降解活性。实验结果表明,当TiO_2与Fe_3O_4的质量比为0.75、初始溶液p H为3.0时,茜素红去除率最高,光催化反应120 min后,茜素红去除率为100%。表征结果显示,Fe_3O_4-0.75TiO_2复合光催化剂不是核壳结构,而是Fe_3O_4和TiO_2的聚集体。Fe_3O_4-0.75TiO_2复合光催化剂重复使用5次后茜素红去除率几乎没有下降,活性稳定性极佳。 相似文献
300.
George Pouliot Venkatesh Rao Jessica L. McCarty Amber Soja 《Journal of the Air & Waste Management Association (1995)》2017,67(5):613-622
Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. One component of the biomass burning inventory, crop residue burning, has been poorly characterized in the National Emissions Inventory (NEI). In the 2011 NEI, wildland fires, prescribed fires, and crop residue burning collectively were the largest source of PM2.5. This paper summarizes our 2014 NEI method to estimate crop residue burning emissions and grass/pasture burning emissions using remote sensing data and field information and literature-based, crop-specific emission factors. We focus on both the postharvest and pre-harvest burning that takes place with bluegrass, corn, cotton, rice, soybeans, sugarcane and wheat. Estimates for 2014 indicate that over the continental United States (CONUS), crop residue burning excluding all areas identified as Pasture/Grass, Grassland Herbaceous, and Pasture/Hay occurred over approximately 1.5 million acres of land and produced 19,600 short tons of PM2.5. For areas identified as Pasture/Grass, Grassland Herbaceous, and Pasture/Hay, biomass burning emissions occurred over approximately 1.6 million acres of land and produced 30,000 short tons of PM2.5. This estimate compares with the 2011 NEI and 2008 NEI as follows: 2008: 49,650 short tons and 2011: 141,180 short tons. Note that in the previous two NEIs rangeland burning was not well defined and so the comparison is not exact. The remote sensing data also provided verification of our existing diurnal profile for crop residue burning emissions used in chemical transport modeling. In addition, the entire database used to estimate this sector of emissions is available on EPA’s Clearinghouse for Inventories and Emission Factors (CHIEF, http://www3.epa.gov/ttn/chief/index.html).Implications: Estimates of crop residue burning and rangeland burning emissions can be improved by using satellite detections. Local information is helpful in distinguishing crop residue and rangeland burning from all other types of fires. 相似文献