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81.
82.
生物质炭的性质及其对土壤环境功能影响的研究进展 总被引:37,自引:0,他引:37
在厌氧或者绝氧的条件下对生物质进行热解,可产生含碳丰富的固体物质,称为生物质炭。由于生物质炭在农业和环境中的巨大应用前景和对土壤碳的增汇减排作用,近期成为土壤学和环境科学的研究热点。综述了生物质炭的一些基本性质及其对土壤环境功能的影响,分析了该领域未来的发展趋势。国内外的研究表明:生物质炭含有大量植物所需的营养元素,可以促进土壤养分的循环和植物的生长;生物质炭一般呈碱性,施用生物质炭可以降低土壤的酸度和有毒元素如铝和重金属对植物的毒性;生物质炭表面含有丰富的-COOH、-COH和-OH等含氧官能团,它们产生的表面负电荷使生物质炭具有较高的阳离子交换量(CEC),施用后可以提高土壤的CEC;生物质炭对农药等有机污染物和重金属等有很强的吸附能力,可用于污染土壤的修复;生物质炭具有高度的孔隙结构,可以增加土壤的空隙度和保水能力,降低土壤容重,有利植物根系生长;生物质炭是一种含碳的聚合物,主要由单环和多环的芳香族化合物组成,这种结构特点决定了生物质炭具有较高的化学和生物学稳定性,较强的抵抗微生物分解的能力,增强了土壤的固碳作用,减少碳向大气的再释放。该文可为从事农业废弃物的资源化利用、固碳减排、污染土壤修复和土壤改良与管理等领域的科研人员提供参考。 相似文献
83.
The dynamics of arsenic in four paddy fields in the Bengal delta 总被引:4,自引:0,他引:4
Stroud JL Norton GJ Islam MR Dasgupta T White RP Price AH Meharg AA McGrath SP Zhao FJ 《Environmental pollution (Barking, Essex : 1987)》2011,159(4):947-953
Irrigation with arsenic contaminated groundwater in the Bengal Delta may lead to As accumulation in the soil and rice grain. The dynamics of As concentration and speciation in paddy fields during dry season (boro) rice cultivation were investigated at 4 sites in Bangladesh and West Bengal, India. Three sites which were irrigated with high As groundwater had elevated As concentrations in the soils, showing a significant gradient from the irrigation inlet across the field. Arsenic concentration and speciation in soil pore water varied temporally and spatially; higher As concentrations were associated with an increasing percentage of arsenite, indicating a reductive mobilization. Concentrations of As in rice grain varied by 2-7 fold within individual fields and were poorly related with the soil As concentration. A field site employing alternating flooded-dry irrigation produced the lowest range of grain As concentration, suggesting a lower soil As availability caused by periodic aerobic conditions. 相似文献
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87.
微波萃取技术在分析土壤中有机污染物的应用 总被引:13,自引:0,他引:13
介绍了微波萃取技术及其使用的试剂、设备和条件,对微波萃取在分析土壤中有机污染物的应用予以综述,阐述了微波萃取技术是分析土壤中有机污染物的好方法。 相似文献
88.
Thomas G. Reichenauer Sunil Panamulla Siripala Subasinghe Bernhard Wimmer 《Environmental geochemistry and health》2009,31(5):573-579
The tsunami disaster in the Indian Ocean in December 2004 caused devastation of agricultural soils by salt water over wide
areas. Many rice fields located close to the coast were affected by the flood of seawater. Electric conductivity (EC) of soils
in tsunami-affected rice fields was found to be higher compared to unaffected fields 2 years after the tsunami. Four soil
amendments (gypsum, dolomite, cinnamon ash and rice-husk-charcoal) were tested for their influence on improving the yield
parameters of rice grown in a tsunami-affected and a non-affected area. Yield parameters were compared with an untreated control
of the same cultivar (AT362) and with a salt resistant rice variety (AT354). The salt resistant variety had the highest grain
yield. The two amendments gypsum and rice-husk-charcoal led to an increase in grain yield compared to the untreated control,
whereas dolomite and cinnamon ash had no significant effect on grain yield. 相似文献
89.
Soil factors associated with zinc deficiency in crops and humans 总被引:10,自引:0,他引:10
B. J. Alloway 《Environmental geochemistry and health》2009,31(5):537-548
Zinc deficiency is the most ubiquitous micronutrient deficiency problem in world crops. Zinc is essential for both plants
and animals because it is a structural constituent and regulatory co-factor in enzymes and proteins involved in many biochemical
pathways. Millions of hectares of cropland are affected by Zn deficiency and approximately one-third of the human population
suffers from an inadequate intake of Zn. The main soil factors affecting the availability of Zn to plants are low total Zn
contents, high pH, high calcite and organic matter contents and high concentrations of Na, Ca, Mg, bicarbonate and phosphate
in the soil solution or in labile forms. Maize is the most susceptible cereal crop, but wheat grown on calcareous soils and
lowland rice on flooded soils are also highly prone to Zn deficiency. Zinc fertilizers are used in the prevention of Zn deficiency
and in the biofortification of cereal grains. 相似文献
90.
Transmissible spongiform encephalopathies (TSEs) are a group of fatal neurological conditions affecting a number of mammals,
including sheep and goats (scrapie), cows (BSE), and humans (Creutzfeldt-Jakob disease). The diseases are widely believed
to be caused by the misfolding of the normal prion protein to a pathological isoform, which is thought to act as an infectious
agent. Outbreaks of the disease are commonly attributed to contaminated feed and genetic susceptibility. However, the implication
of copper and manganese in the pathology of the disease, and its apparent geographical clustering, have prompted suggestions
of a link with trace elements in the environment. Nevertheless, studies of soils at regional scales have failed to provide
evidence of an environmental risk factor. This study uses geostatistical techniques to investigate the correlations between
the distribution of TSE prevalence and soil geochemical variables across the UK according to different spatial scales. A similar
spatial pattern in scrapie and BSE occurrence is identified, which may be linked with increasing pH and total organic carbon,
and decreasing iodine concentration. However, the pattern also resembles that of the density of dairy farming. Nevertheless,
despite the low spatial resolution of the TSE data available for this study, the fact that significant correlations are detected
indicates there is a possibility of a link between soil geochemistry, scrapie, and BSE. It is suggested that further investigations
of the prevalence of TSE and environmental exposure to trace metals should take into account the factors affecting their bioavailability. 相似文献