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1.
大亚湾微表层和次表层海水营养盐的研究   总被引:11,自引:0,他引:11  
根据1998年秋季(10、11月)、1999年春、秋季(4、5、10月)5个航次对大亚湾海区微、次表层的调查结果,分析了微表层海水对氮、磷、硅营养盐的富集概况,讨论了营养盐与环境因子的关系。结果表明:大亚湾海区微表层海水对氮、磷、硅营养盐均有富集作用,因海况及季节不同,富集因数(EF)与其他海区的有所差别;无论夏季或秋季,大亚湾海区微表层海水中无机氮都以NH4-N为主要存在形态;其余水层则以NO3-N为主要存在形态。结果还表明,微表层、次表层海水中NH4-N与BOD5、COD测值都呈高度显著正相关,与PO4-P和SiO3-Si含量均无相关,说明大亚湾海区水中含氮有机物较含磷有机物丰富。  相似文献   
2.
Gas exchange experiments were conducted in the tropical Atlantic Ocean during a ship expedition with FS Meteor using a small rubber raft. The temporal change of the mixing ratios of CO, H2, CH4 and N2O in the headspace of a floating glass box and the concentrations of these gases in the water phase were measured to determine their transfer velocities across the ocean-atmosphere interface. The ocean acted as a sink for these gases when the water was undersaturated with respect to the mixing ratio in the headspace. The transfer velocities were different for the individual gases and showed still large differences even when normalized for diffusivity. Applying the laminar film model, film thicknesses of 20 to 70 m were calculated for the observed flux rates of the different gas species. When the water was supersaturated with respect to atmospheric CO, H2, CH4 and N2O, the transfer velocities of the emission process were smaller than those determined for the deposition process. In case of H2 and CH4, emission was even not calculable although, based on the observed gradient, the laminar film model predicted significant fluxes at the air-sea interface. The results are interpreted by destruction processes active within the surface microlayer.  相似文献   
3.
Polycyclic aromatic hydrocarbons (PAHs) were measured in the coastal sea surface microlayer (SML), the sub-surface waters (SSW) and the overlying atmosphere in order to investigate the influence of the SML on contaminant enrichment and air-sea exchange. Samples were collected at two contrasting locations of the NW Mediterranean, one urban influenced (off Barcelona, Spain) and another comparatively clean (off Banyuls-sur-Mer, France). Statistical data analysis confirmed the accumulation of PAHs in the SML with respect to the SSW (20.3+/-9.1 vs. 13.1+/-10.0 ng L(-1) in the dissolved phase; 709+/-207 vs. 158+/-111 ng g(-1) in the particulate phase). This accumulation was higher at the contaminated location (Barcelona station) compared with the more pristine one, with PAH enrichments 1.5 and 4.5 times higher for the dissolved and particulate phases, respectively, indicating that the enrichment of PAHs in the SML is dominated by particle transport processes.  相似文献   
4.
《Polar Science》2014,8(1):10-23
This study compares the common harmonic constants of the O1, K1, P1, Q1, M2, S2, N2, and K2 tidal constituents from eight global and four regional tide models with harmonic constants from satellite altimeter and tide gauge data for the northern region of the Antarctic Peninsula (58°S–66°S, 53°W–66°W). To obtain a more representative comparison, the study area was divided into three zones with different physical characteristics but similar maximum tidal amplitude variations: Zone I (north of 62°S), Zone II (south of 62°S and west of the Antarctic Peninsula), and Zone III (between 62°S and 64.3°S, and east of 58.5°W). Root sum square (RSS) values are less than or equal to 3.0, 4.2, and 8.4 cm for zones I, II, and III, respectively. No single model shows superior performance in all zones. Because there are insufficient satellite altimetry observations in the vicinity of Matienzo Base (64.9761°S, 60.0683°W), this station was analyzed separately and presents the greatest values of both root mean square misfit and RSS. The maximum, minimum, and average amplitude values of the constituents that follow in importance after the eight common tidal constituents, and which have amplitudes greater than 1 cm, are also analyzed.  相似文献   
5.
1 INTRODUCTION Bioavailability to the biota and the biogeo-chemistry of trace metals in marine environment areaffected by their chemical speciation in the naturalsystem (Bruland et al., 1991; Van den Berg andDonat, 1992; Wells et al., 1998). Therefore, thesetwo parameters, the ligands concentrations andconditional stability constants, are important todetermine the complexing capacity. Sea surface microlayer (SML), the thin interfa-cial boundary between ocean and atmosphere, playsan imp…  相似文献   
6.
Wurl O  Obbard JP 《Marine pollution bulletin》2004,48(11-12):1016-1030
Boundary layers between different environmental compartments represent critical interfaces for biological, chemical and physical processes. The sea-surface microlayer (uppermost 1-1000 microm layer) forms the boundary layer interface between the atmosphere and ocean. Environmental processes are controlled by the SML, and it is known to play a key role in the global distribution of anthropogenic pollutants. Due to its unique chemical composition, the upper organic film of the SML represents both a sink and a source for a range of pollutants including chlorinated hydrocarbons, organotin compounds, petroleum hydrocarbons, polycyclic aromatic hydrocarbons (PAH) and heavy metals. These pollutants can be enriched in the SML by up to 500 times relative to concentrations occurring in the underlying bulk water column. The SML is also a unique ecosystem, serving as an important habitat for fish eggs and larvae. Concentration ranges and enrichment factors of pollutants in the SML in different areas of the world's oceans have been critically reviewed, together with available toxicity data for marine biota found within the SML. Overall, the SML is highly contaminated in many urban and industrialized areas of the world, resulting in severe ecotoxicological impacts. Such impacts may lead to drastic effects on the marine food web and to fishery recruitment in coastal waters. Studies of the toxicity of fish eggs and larvae exposed to the SML contaminants have shown that the SML in polluted areas leads to significantly higher rates of mortality and abnormality of fish embryos and larvae.  相似文献   
7.
Dimethylsulfide enrichment in the surface microlayer of the South China Sea   总被引:5,自引:0,他引:5  
A total of 22 sea surface microlayer samples collected from the Nansha Islands waters of the South China Sea were analyzed for dimethylsulfide (DMS), chlorophyll a and nutrients including nitrate, phosphate and silicate. The DMS concentrations in surface microlayer samples ranged from 82 to 280 ng S/l with a mean of 145 ng S/l. A significant correlation was found between DMS and chlorophyll a data both in the surface microlayer as well as in the subsurface water. However, no correlation was observed between DMS and nutrient concentrations in the surface microlayer. The DMS concentrations were higher in all surface microlayer samples, compared with subsurface samples. The enrichment factor (EF) of DMS in the surface microlayer varied from 1.21 to 3.08 with an average of 1.95. The EF of DMS was significantly correlated with that of chlorophyll a in the microlayer. The enrichment of DMS in the microlayer may be due to two factors, including the in situ production from phytoplankton and the transportation from the underlying seawater. The diel variations in DMS and chlorophyll a concentrations were studied at a fixed station. The highest concentrations of DMS in the surface microlayer and subsurface water were simultaneously observed in the late afternoon (1800 h), while the highest levels of chlorophyll a were simultaneously found at night (0200 h).  相似文献   
8.
A study was done to determine the concentrations of surfactants on the sea-surface microlayer and in atmospheric aerosols in several coastal areas around the Malaysian peninsula. The concentrations of surfactants from the sea-surface microlayer (collected using rotation drum) and from aerosols (collected using HVS) were analyzed as methylene blue active substances and disulphine blue active substances through the colorimetric method using a UV-vis spectrophotometer. The results of this study showed that the average concentrations of surfactants in the sea-surface microlayer ranged between undetected and 0.36 ± 0.34 μmol L−1 for MBAS and between 0.11 ± 0.02 and 0.21 ± 0.13 μmol L−1 for DBAS. The contribution of surfactants from the sea-surface microlayer to the composition of surfactants in atmospheric aerosols appears to be very minimal and more dominant in fine mode aerosols.  相似文献   
9.
Aliphatic (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed in dissolved and particulate material from surface microlayer (SML) and subsurface water (SSW) sampled at nearshore observation stations, sewage effluents and harbour sites from Marseilles coastal area (Northwestern Mediterranean) in 2009 and 2010. Dissolved and particulate AH concentrations ranged 0.05–0.41 and 0.04–4.3 μg l−1 in the SSW, peaking up to 38 and 1366 μg l−1 in the SML, respectively. Dissolved and particulate PAHs ranged 1.9–98 and 1.9–21 ng l−1 in the SSW, amounting up 217 and 1597 ng l−1 in the SML, respectively. In harbours, hydrocarbons were concentrated in the SML, with enrichment factors reaching 1138 for particulate AHs. Besides episodic dominance of biogenic and pyrogenic inputs, a moderate anthropisation from petrogenic sources dominated suggesting the impact of shipping traffic and surface runoffs on this urbanised area. Rainfalls increased hydrocarbon concentrations by a factor 1.9–11.5 in the dissolved phase.  相似文献   
10.
于2013年12月3日清晨、正午、傍晚采集了大亚湾大鹏澳海域3个站位的微表层和次表层水样,经过三级分级过滤(小型:20μm;微型:2.7~20μm;微微型:2.7μm)后,对其进行高效液相色谱(HPLC)色素分析,通过藻类色素化学分类法(CHEMTAX)分析不同浮游植物对Chl a的贡献,研究了微表层及次表层光合色素粒径特征及浮游植物群落结构差异。结果表明,冬季大亚湾海域水体中存在的浮游植物光合色素主要有17种,以岩藻黄素和Chl a含量较高。微表层总Chl a平均浓度为0.797μg/L,略高于次表层的0.714μg/L,不存在显著性差异(P0.05);微表层和次表层Chl a含量清晨最高,傍晚次之,正午最低。微表层不同粒径浮游植物对Chl a的贡献率从大到小依次为小型、微型、微微型浮游植物,分别为80.7%,10.1%和9.2%。CHEMTAX分析结果得出,冬季该海域硅藻占绝对优势,甲藻、定鞭藻、青绿藻、蓝藻、隐藻所占比重相差不大。微表层中定鞭藻、青绿藻和蓝藻等较小粒径浮游植物种群所占比重高于次表层,说明相对于次表层,微表层中的浮游植物群落有小型化趋势。  相似文献   
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