全文获取类型
收费全文 | 28篇 |
免费 | 1篇 |
国内免费 | 41篇 |
专业分类
大气科学 | 1篇 |
地球物理 | 4篇 |
地质学 | 9篇 |
海洋学 | 37篇 |
综合类 | 18篇 |
自然地理 | 1篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 9篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1990年 | 1篇 |
排序方式: 共有70条查询结果,搜索用时 250 毫秒
1.
CH3I、CHCl3、C2HCl3和CH2Br2是挥发性卤代烃4种重要成分,对大气化学产生重要影响。于2018年10月在西太平洋进行船基现场培养实验,研究微量元素Fe (50 nmol/L)、酸化(pH=7.9)、酸化(pH=7.9)和微量元素Fe (50 nmol/L)耦合作用、微量元素Fe (50 nmol/L)和N/P (16∶1)耦合作用及沙尘(4 mg/L)对浮游植物释放CH3I、CHCl3、C2HCl3和CH2Br2含量的影响。结果表明,与对照组相比,实验组CH3I、C2HCl3和CH2Br2的释放均被不同程度抑制;CHCl3的释放除添加沙尘时表现抑制作用外,其他条件下均为促进作用;实验组培养周期内叶绿素a浓度较高,而营养盐浓度变化规律不明显。总的来说,酸化和微量元素Fe可能是影响浮游植物释放挥发性卤代烃的重要限制因素,沙尘对促进浮游植物生长繁殖的影响更为显著。 相似文献
2.
海洋溢油污染对生物群落和种群的影响及生态系统的恢复 总被引:1,自引:0,他引:1
海洋溢油污染带来的最严重的威胁在于它能够改变或破坏海洋环境中正常存在的生态系统。溢油污染对生态系统的初步影响是造成生物物种多样性、丰度、均匀度下降,进一步则是敏感物种消退,另一些机会物种大量繁殖,群落结构受到扰动。受到溢油污染后的生物群落的变化和恢复过程通常呈现的是多种因素共同作用的结果。溢油作为一种外来的扰动因素,对生态系统的发展强行加注了一种相对统一的发展模式,生态系统会经历一些优势种之间强烈的相互作用,种群数量出现大幅度的波动,系统变得敏感脆弱,生态恢复需要一定的时间。本文对国内外几十年来的研究成果进行综述,总结今后应大力开展海洋石油污染调查研究工作的各个方面。 相似文献
3.
夏季黄海冷水团海域的丙烯酸分布与海洋环境因子和叶绿素a变化之间的关系 总被引:1,自引:0,他引:1
海水中主要含硫化合物β-二甲基巯基丙酸内盐(DMSP)降解可产生丙烯酸(AA)和活性气体二甲基硫(DMS)。2011年8月对黄海冷水团海域的AA及相关参量的分布特征进行了研究。结果表明,该海域表层海水中AA的浓度为0~0.208μmol/L,平均值为(0.081±0.075)μmol/L。AA的高值区出现在海域的东南部,可能是受到长江冲淡水的影响。AA的浓度总体上呈现出由南到北递增的趋势,与Chl-a较为一致,表明该海域的AA主要是由DMSP裂解产生的。表层海水中AA与温度表现出明显的负相关性。AA的垂直分布表现为:中层底层表层,这可能是产生AA的浮游植物与消耗AA的细菌共同作用的结果。海域中AA浓度与DMSP或DMS无明显的相关性。AA浓度远高于DMS,AA/DMS平均为106∶1,初步估算出DMSP降解产生的AA约为66.5%。AA/Chl-a平均为126.6 mmol/g,比DMSP/Chl-a高1个数量级,比DMS/Chl-a高2个数量级。 相似文献
4.
Huang Yuhuan Sun Chengjun Yang Guipeng Yue Xinan Jiang Fenghua Cao Wei Yin Xiaofei Guo Chaonan Niu Jiaohong Ding Haibing 《中国海洋湖沼学报》2020,38(3):650-664
Journal of Oceanology and Limnology - Two sediment cores were retrieved in the hadal zone of the Yap Trench, and their concentrations of six major elements Mg, Al, Ca, Ti, Mn and Fe and nine trace... 相似文献
5.
Seasonal and spatial distributions of dissolved and particulate dimethylsulfoxide(DMSOd,DMSOp)were measured in the East China Sea and the Yellow Sea during March–April 2011 and October–November 2011.The concentrations of DMSOd and DMSOp in the surface water were 20.6(5.13–73.8)and 8.90(3.75–29.6)nmol/L in spring,and 13.4(4.17–42.7)and 8.18(3.44–22.6)nmol/L in autumn,respectively.Both DMSOd and DMSOp concentrations revealed similar seasonal changes with higher values occurring in spring,mainly because of the higher phytoplankton biomass observed in spring.Moreover,the ratios of DMSOp/chlorophyll a also exhibited an apparent seasonal change with higher values in autumn(35.7 mmol/g)and lower values in spring(23.4 mmol/g),thereby corresponding with the seasonal variation in the proportion of DMSO producers in the phytoplankton community between spring and autumn.In addition,DMSOd and DMSOp concentrations in the surface seawater revealed obvious diurnal variations with the maxima appearing in the afternoon. 相似文献
6.
Systematic study on sorption behavior of o-nitrophenol on marine sediments was conducted.Isotherms of sorption of o-nitrophenol on marine sediments could be described by Freundlich model; and the isotherm of sorption of o-nitrophenol on HCl-treated sediment could be described by Langmuir model. The sorption behavior was affected by various factors including organic carbon content, aqueous solution salinity,temperature, and acidity. The sorption amount of o-nitrophenol increased when salinity and acidity of the aqueous solution increase, but decreased with increasing temperature. Organic carbon content in sediments had apparent effect on the behavior except for HCl-treated sediments. 相似文献
7.
Guo Chaonan Sun Chengjun Yang Guipeng Zhang Honghai Chen Yan Yin Xiaofei Jiang Fenghua Huang Yuhuan Niu Jiaohong Ding Haibing 《中国海洋湖沼学报》2020,38(3):606-618
Journal of Oceanology and Limnology - The concentrations of dissolved monosaccharides (MCHO), polysaccharides (PCHO), and total carbohydrates (TCHO) in the seawater samples collected from the north... 相似文献
8.
二甲基硫光化学氧化反应的动力学研究 总被引:1,自引:1,他引:1
实验研究水溶液中二甲基硫(DMS)的光化学氧化反应的动力学。结果表明,在入射光频率与强度一定条件下,DMS进行光化学氧化反应的速率会受到介质、pH、重金属离子的影响。Hg2+能显著加快人工海水介质中DMS的光氧化速率。DMS进行光氧化的一级速率常数为4.46×10-5~30.4×10-5s-1,其在光照下的人工海水介质中的半寿期为3.6h。这说明光化学过程对于影响和控制DMS在海洋中的浓度和分布起着十分重要的作用 相似文献
9.
Fatty acids(FAs) in sediment collected from three different stations in the Yellow Sea and the East China Sea were analyzed for their distributions and to determine evidence of harmful algal blooms in the sediment core.Less diverse FAs were found in the Yellow Sea(YS) station,whereas in the two stations of the East China Sea(ECS) the FAs were more diverse.Concentrations of some FA species in the two ECS stations displayed an occasional surge in their vertical profile.The highest concentration of FAs was found in the surface layer of station QT3(43.28 μg g~(-1)).Monounsaturated FAs were more susceptible to degradation compared to their saturated counterparts,and changes of 16:0,18:2 and 20:5 accounted for the most variability in total concentrations of FAs as those species made up most of the quantified FAs.The origins of the major fraction of FAs were attributed to autotrophic sources,and bacterial FAs accounted for only a small fraction of the total FAs in the region.Nutrient availability was a possible regulating factor controlling bacteria abundances in marine sediments in the ECS and the YS.A principal component analysis(PCA) was applied to analyze the FA dataset and to reveal the principal environmental factors that control the composition of FAs in the sediments.PC2,which explains 15% of the variance,was estimated to reflect the diagenetic effects on the FA compositional changes in sediments influenced by bacterial degradation. 相似文献
10.