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941.
Marine bacteria have recently been identified as a potent solution for petroleum hydrocarbon degradation in response to hazardous oceanic oil spills. In this study, a mesocosm experiment simulating a petroleum spill event was performed to investigate changes in the abundance, structure, and productivity of bacterial communities in response to oil pollution. Cultured heterotrophic bacteria and total bacteria showed a consistent trend involving an immediate decrease in abundance, followed by a slight increase, and a steady low-level thereafter. However, the changing trend of bacterial productivity based on bacterial biomass and bacterial volume showed the opposite trend. In addition, the density of oil-degrading bacteria increased initially, then subsequently declined. The change in the bacterial community structure at day 0 and day 28 were also analyzed by amplified ribosomal DNA restriction analysis (ARDRA), which indicated that the species diversity of the bacterial community changed greatly after oil pollution. Alphaproteobacteria (40.98%) replaced Epsilonproteobacteria (51.10%) as the most abundant class, and Gammaproteobacteria (38.80%) became the second most dominant class in the whole bacterial community. The bacterial communities in oil-contaminated seawater (32 genera) became much more complex than those found in the natural seawater sample (16 genera). The proportion of petroleum-degrading bacteria in the oil-contaminated seawater also increased. In this study, culture-dependent and culture-independent approaches were combined to elucidate changes in both bacterial productivity and community structure. These findings will contribute to a better understanding of the role that bacteria play in material cycling and degradation in response to oil pollution. 相似文献
942.
利用微生物来降解土壤中的石油类污染物,是当前应用前景最好的土壤石油处理方法。多种因素同时制约着石油类污染物的生物降解。为了定量化各因素对彼此的影响,探求促进正向作用、抑制负向作用的途径,为各因素制定适宜的施用时间顺序以及施用量,以最大限度地加快降解速度,笔者设计了本文中的生物降解实验。结果表明,使用多因素复合处理方法可以在土壤石油处理中收到很好的效果;在实验的不同阶段,各影响因素的重要性及最优水平也会不同程度地变化。 相似文献
943.
陆源污染是半封闭海湾环境恶化的主要原因,评估海湾地区陆源污染的生态损害,对目前迫切需要制定的海洋生态损害补偿政策以及生态修复计划具有重要的现实意义。本文以象山港为研究区域,运用生态恢复评估与生态服务价值评估相结合的方法,构建陆源污染生态损害评估模型,进行陆源污染对海湾生态服务损害评估与补偿标准研究。结果显示:(1)象山港陆源污染造成的生态服务损害价值为38 342.81万元,执行损害评估的费用约为20万元;以生态损害评估的总费用作为补偿标准,生态补偿费用共计38 362.81万元,单位面积补偿价值为0.42万元/hm~2·a。(2)象山港陆源污染所导致的海洋生态系统初始性修复成本为零,恢复期内损害价值主要以养分循环和净化环境为主,分别为19 740.72万元和13 938.13万元;美学景观损害价值为3 798.59万元,占比为9.91%;生物多样性维持损害价值598.66万元,占比为1.56%;食物生产的损害价值最小,为266.72万元。 相似文献
944.
Jianxiu Wang Yansheng Deng Dongsheng Song Wuji Liu Mingzhi Hu 《Marine Georesources & Geotechnology》2018,36(5):603-616
Large-scale reclamation projects have been developing rapidly in China’s coastal lands since 2000. In this study, the scale and pollutant contents of reclaimed lands were collected from published data and field surveys. Over 80% of the gross area was formed using hydraulic reclaimed technology. The pollution index, geoaccumulation index, and Nemerow integrated pollution index (NIPI) of 13 pollutant types were calculated based on the collected data. The potential pollution within major newly reclaimed lands was evaluated with valid pollutant data from sediments of the neighboring water. All reclaimed lands larger than 30?km2 were slightly to seriously polluted with Cu, Pb, Zn, Cd, Cr, Hg, As, and Ni according to NIPI. The reclaimed fields in Hengsha Island, Binhai Tower, and Lingang New City of Shanghai were selected as verification sites for the pollution evaluations. The Cu, Pb, Zn, Cd, Cr, As, and Ni concentrations in dredged soils determined through inductively coupled plasma mass spectrometry showed a generally good soil quality within the typical reclaimed fields. Principal component and hierarchical clustering analyses indicated that the relatively high As content in the reclaimed soils was due to the internal pollutants of dredging fills and originated from anthropogenic sources. 相似文献
945.
C Kosore L Ojwang J Maghanga J Kamau A Kimeli J Omukoto 《African Journal of Marine Science》2018,40(3):225-234
Microplastics can be ingested by marine organisms and may lead to negative impacts at the base of marine food chains. This study investigated the occurrence and composition of microplastics in the sea-surface water and sought evidence of ingestion by zooplankton. Surface seawater was collected using a stainless-steel bucket and sieved directly through a stainless-steel sieve (250-µm mesh), while a 500-μm mesh net was towed horizontally to collect zooplankton, at 11 georeferenced stations off the Kenyan coast in February 2017, on board the national research vessel RV Mtafiti. Microplastic particles were sorted and characterised using an Optika dissecting microscope. Polymer types were identified using an ALPHA Platinum attenuated total reflection—Fourier-transform infrared (ATR-FTIR) spectrometer. A total of 149 microplastic particles, with an average abundance of 110 particles m–3, were found in the surface seawater. A total of 129 particles were found ingested by zooplankton groups, where Chaetognatha, Copepoda, Amphipoda and fish larvae ingested 0.46, 0.33, 0.22 and 0.16 particles ind.–1, respectively. Filaments dominated both the surface-water microplastics and the ingested microplastics, contributing 76% and 97% to those compositions, respectively. White particles were prevalent in the water (51%), whereas black was the colour found most commonly (42%) across the zooplankton groups. The sizes of particles that were in the water were in the range of 0.25–2.4 mm, and those ingested ranged between 0.01 and 1.6 mm. Polypropylene was predominant in the surface water, whereas low-density polyethylene was the most-ingested polymer type. The results provide the first documented evidence of the occurrence, composition and ingestion of microplastics by zooplankton in Kenya's marine environment, indicating that microplastics have the potential to enter pelagic food webs and cause pollution in the study area. 相似文献
946.
Misganaw DEMISSIE 《国际泥沙研究》1999,(2)
1INTRODUCTIONTileillinoisRiver,oneofthemajortributariestotheMississippiRiverinthecentralUnitedStates,hasadrainageareaof75,156kmZthatcoversportionsof1llinois,Indiana,andWisconsin(Figllre1).Asaresultofrepeatedlevelingbyglaciers,mostofthe1llinoisRiverwatershedisflatandcoveredwithfineloesssoil,makingitoneofthebestagriculturalregionsinNorthAmerica.Morethan80percentoftheIllinoisRiverbasinispresentlyusedforagricultUralpurposes.IllinoisagricultUrestartedtoexpandveryrapidlyinthe19thcentury,g… 相似文献
947.
The Ganga Plain is one of the most densely populated regions and one of the largest groundwater repositories of the Earth.
For several decades, the drainage basin of the Ganga Plain has been used for the disposal of domestic and industrial wastes
which has adversely affected the quality of water, sediments and agricultural soils of the plain. The concentrations of Al,
Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, Zn and organic carbon were determined in river sediments and soils of the Ganga Plain
in the Kanpur-Unnao industrial region in 1994 and 1995 (pre-monsoon period of April–May). High contents (maximum values) of
C-org (12.0 wt. %), Cr (3.40 wt. %), Sn (1.92 wt. %), Zn (4000 mg/kg), Pb (646 mg/kg), Cu (408 mg/kg), Ni (502 mg/kg) and
Cd (9.8 mg/kg) in sediments (<20 μm fraction); and C-org (5.9 wt. %), Cr (2.16 wt. %), Sn (1.21 wt %), Zn (975 mg/kg) and
Ni (482 mg/kg) in soils (<20 μm) in the pre-monsoon period of 1994 were found. From 1994 to 1995 the contents of Fe and Sn
in sediments increase whereas those of C-org, Cd, Cu, Ni and Zn decrease. Considering the analytical errors, Al, Co, Cr, Mn
and Pb do not show any change in their concentrations. In soils, the contents of Cd, Fe and Sn increase whereas those of Ni
decrease from 1994 to 1995. Aluminium, Co, Cr, Cu, Mn, Pb and Zn do not show any change in their concentrations from 1994
to 1995. About 90% of the contents of Cd, Cr and Sn; 50–75% of C-org, Cu and Zn; and 25% of Co, Ni and Pb in sediments are
derived from the anthropogenic input in relation to the natural background values, whereas in soils this is the case for about
90% of Cr and Sn; about 75% of Cd; and about 25% of C-org, Cu, Ni and Zn. The sediments of the study area show enrichment
factors of 23.6 for Cr, 14.7 for Cd, 12.2 for Sn, 3.6 for C-org, 3.2 for Zn, 2.6 for Cu and 1.6 for Ni. The soils are enriched
with factors of 10.7 for Cr, 9.0 for Sn, 3.6 for Cd, 1.8 for Ni and 1.5 for Cu and Zn, respectively.
Received: 3 March 1998 · Accepted: 15 June 1998 相似文献
948.
Ankara Creek is often subjected to overflowing of sewage caused by rainfall or direct discharge of raw sewage. Alluvial aquifers
adjacent to Ankara Creek and its tributaries have considerable groundwater potential. The present status of groundwater quality
is far from drinking water standards. Groundwater contamination in Ankara is suspected to be caused by Ankara Creek which
is heavily polluted by raw sewage discharge, surface runoff and other common sources. In order to investigate the influence
of heavily polluted Ankara Creek on the groundwater contamination in the adjacent alluvial aquifers, five sampling stations
on Ankara Creek and 25 water wells were monitored during 1996. At five different sampling periods, water samples were collected
from both surface water and groundwater. Chemical analyses of basic ions, pollution parameters and heavy metals in natural
waters were carried out. The organic pollution prevails in Ankara Creek whereas total dissolved solids (TDS) and heavy metal
concentrations are considerably low. Starting from the idea that Ankara Creek somewhat influences the groundwater quality
and the contaminants in groundwater should attenuate with respect to distance, a series of water wells in a certain area,
each having different distance from the creek, were examined using four pollution parameters. It is concluded that Ankara
Creek barely influences the aquifer systems in connection. This is attributed to two reasons: rapid attenuation of contaminants
due to dilution in groundwater and a blanket of very fine sized materials covering the bottom of Ankara Creek.
Received: 28. April 1997 · Accepted: 23. February 1998 相似文献
949.
In the present paper, an environmental analysis of Manikpur area, Korba coalfield, Bilaspur, M.P., India is undertaken. The
area lies in the Geological Survey of India Toposheet no. 64J/11 Latitude 82°42′54″–82°45′10″ North; Longitude 22°18′46″–22°19′46″
East. The paper deals with pollution and its control measures through the natural plants found in the vicinity of the coalmines,
namely Mangifera indica, Eucalyptus spp., Cassia siamea, Delbergia sissoo, etc. The plants control the Suspended Particulate Matter (SPM), Nitrous Oxides (NOx), Sulphur Oxides (SOx) of the mines
and mining site. Therefore, plantation in the mining site should be encouraged.
Received: 12 May 1998 · Accepted: 6 October 1998 相似文献
950.
通过研究大洋锰结核经氨浸工艺提取Co,Ni,Cu等有价金属后的粉末状固体残渣(氨浸渣)对石英-长石-高岭土3组分陶瓷体系烧结行为及制品性能的影响发现:3组分体系中添加不超过10%的氨浸渣,在1140℃烧结90min,烧结体的抗折强度大于65.9MPa,吸水率小于0.128%.达到JC/T665-1997规定的要求。氨浸渣的助熔效果明显,添加5%~10%即可降低3组分陶瓷烧结温度40℃~80℃,添加量过多(超过10%)会增加熔体相含量.易引起坯体过烧,不利于坯体致密化和烧成工艺控制。添加氨浸渣,烧结体呈灰白色一黄褐色,且烧结体颜色随氨浸渣含量增加而变深。研究认为,氨浸渣可以作为石英-长石-高岭土3组分陶瓷的助熔剂和色料。 相似文献