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531.
在四川甘溪和贵州独山泥盆纪剖面的造礁珊瑚-层孔虫薄片中,发育多种菌藻类及其生物遗迹:主要包括结壳菌藻类、钻孔菌藻类、微钻孔和嵌生;并发现了寄主珊瑚-层孔虫中菌藻类及其遗迹产出部位具有骨骼残缺和虫室中常见软体组织死后的残留物质.我们的资料表明,菌藻类与寄主珊瑚-层孔虫之间是"侵略与反抗"的关系,前者对后者生长有抑制作用,后者有一定自我修复功能,二者关系中菌藻类是主动的一方;在适合寄主珊瑚-层孔虫生存环境的中泥盆世,寄主珊瑚-层孔虫能抵抗菌藻类入侵而不会死亡,菌藻类对珊瑚-层孔虫礁生态系的影响很小;在适合菌藻类而不适合珊瑚-层孔虫生长环境的晚泥盆世,后者无法抵抗前者"大举入侵"而出现凋零和死亡.我们认为菌藻类对寄主珊瑚-层孔虫的生长发育的直接抑制与杀死作用和菌藻类繁盛引发的环境恶化是F-F之交珊瑚-层孔虫礁生态系消失的重要原因,这为现代珊瑚礁患病-衰退的原因和发展趋势研究提供了古代实例. 相似文献
532.
编者按:湿地与森林、海洋并称为全球三大生态系统,在调节径流、蓄洪防灾、控制污染、降解有毒有害物质、缓解面积污染、净化水质、维持生物多样性、调节气候、控制土壤侵蚀、美化环境等方面具有十分重要的作用.但近20年来,广西沿海不断扩大的对虾养殖业,已对滨海湿地的生态构成了严重危害.为了让社会各界对滨海湿地的开发和可持续利用问题引起足够重视,自治区政协人口资源环境委员会与民盟广西区委会于2005年秋季赴北海、钦州、防城港等地进行专题调研,本刊现将调研报告编发如下: 相似文献
533.
1 INTRODUCTION Heavy metal pollution in marine environment has always been a serious problem over the last several decades, because most of the heavy metal species that enter marine environment accumulated there without decomposition. Strontium is a minor… 相似文献
534.
A COMPARISON OF EASTERN AND WESTERN HONG KONG PHYTOPLANKTON FROM WEEKLY SAMPLES (1997-1999) 总被引:3,自引:0,他引:3
Weekly phytoplankton samples were taken from western Hong Kong (Lamma) from Jan. 1997 to Dec. 1999 and from Port Shelter in
Eastern Hong Kong from January 1998 to December 1999. During that time diatom blooms occurred repeatedly at both sites but
never in synchrony. One species would bloom at one site and then weeks later it or another species would bloom at the other
site; while the 1998 red tide of the mucus producing dinoflagellateGymnodinium mikimotoi occurred at both sites. It first occurred at the Port Shelter site in March and did not appear at the Lamma site until April.
With the single exception of this species, no other dinoflagellate reached bloom concentrations at the Lamma site. In addition,
dinoflagellate abundance at the Lamma site was significantly lower (P<0.05) than that at the Port Shelter site. This was correlated
with a significantly higher turbidity (i. e. low Secchi transparency) and higher turbulence (stronger currents) at the Lamma
site.
Annual variation in surface temperature correlated with total surface phytoplankton abundance at both our sample sites. Phytoplankton
abundance increased in spring as water temperatures warmed. In fall, as surface water temperatures began to decline and the
monsoon rains became less frequent there was a reduction in phytoplankton abundance associated with the reduction in temperature
and light. Because so many variables co-occur with temperature (e. g. the amount of rainfall light intensity and light duration
etc.) it is not possible to cite temperature as the causal factor associated weth controlling phytoplankton abundance at our
two sample sites.
Our data support the rather controversial notion that percentage-wise, there are relatively more harmful bloom forming species
in nutrient-rich coastal waters than there are in the world's oceans. 16% of the dinoflagellate species and 10.3% of the diatom
species observed at our two sample sites were classed as harmful. These percentages were higher than those cited by Sournia
(1995) for the worlds oceans (9.6% and 6.8% respectively). This raises the possibility that there are relatively more toxic
species in the nutrient-rich coastal waters of the world than there are in the mid ocean nutrient-poor areas of the world.
Some reasons for this are briefly discussed. 相似文献
535.
新立城水库藻类污染成因分析及治理对策措施 总被引:1,自引:0,他引:1
本文对新立城水库发生蓝藻水华事件进行了水质应急监测和污染成因分析.从新立城水库气象条件分析,发现水库水温是历史同期最高值,为藻类在库区内大量迅速繁殖提供了温度条件;从新立城水库坝前、库中和库末氮磷浓度分析,发现水库氮磷浓度均超过富营养化临界值,为藻类在库区内大量迅速繁殖提供了营养条件.本文在分析水库藻类污染成因基础上,提出了从水库管理和现有水处理系统的改进入手,加强新立城水库外源污染控制对策措施和内源污染治理措施. 相似文献
536.
吉林省延边地区早白垩世大拉子组上段地层以含油页岩为特征。松江盆地大拉子组上段油页岩呈灰褐色或灰黑色,表现为纸片状和致密块状。有机质类型为腐泥型-腐殖腐泥型,含油率为3.8%~6.2%。大拉子组上段发育7个含油页岩层位,2号层和7号层为具有工业开采价值的矿层,产状不稳定,自东向西、由南向北累计厚度增大。致密块状油页岩发育于松江向斜轴部杨木屯地区、向斜北翼的老偏坡—东山一线,纸片状油页岩见于向斜南翼的杨木屯—松江镇北以及胜利屯一带。大拉子组上段地层可划分为两个三级层序,2号和7号油页岩矿层皆为半深湖-深湖成因,分别形成于层序I、层序II的高位体系域时期。湖水分层稳定、藻类勃发、半深湖-深湖长期滞水缺氧的还原环境、有机质有效聚集保存有利于油页岩成矿,频繁发育的重力流湖泊水下扇沉积则不利于成矿。 相似文献
537.
Based on the systematic analysis of the coal gangue in Weibei Coalfield, such as petrologic characteristics, chemical composition, nutrient elements, deleterious elements, and the transformation, and compared with the soil element content background values of Loess Plateau and national harmful materials controlling standards, we conclude that the coal gangue in the Weibei Coalfield has huge potential to be used as clay fertilizer. 相似文献
538.
A new adsorption process for the removal of As(V) ion from aqueous solutions is studied in this paper using lanthanum-loaded zeolite. The removal efficiency of different adsorbents, activated alumina and activated carbon are obtained in the study for comparison. The results show that lanthanum-loaded zeolite is an effective adsorbent for the removal of As(V) from aqueous solutions. Then, the pH effect and regeneration of modified zeolite on the As(V) removing efficiency are also assessed. It functions with a wide range of pH (2-8). After adsorption, zeolite adsorbed with As(V) ions can be regenerated successfully with 1 M NaOH. Based on the data obtained, an adsorption mechanism and the possible complex structure are tentatively presented. Compare to other adsorbents, easy availability of this adsorbent, excellent adsorption capacity, wide optimum pH range, and regeneration are expected to be utilized in practical operations. 相似文献
539.
540.
在美国圣地亚哥的一个实验室里,几乎所有的试管都装满了绿色的藻类,这是一种现代化的生物技术,可以避免池塘藻类生长产生的浮渣。试管里装着不同种类的藻类,它们之间进行着生长竞赛,这种竞赛是一种快速生长的进化,其目的是要产生一种"超级藻类",这种超级藻类能高效地将太阳光能和二氧化碳转变为脂类或者油类,然后这些脂类或者油类经过提炼和加工,最终形成汽油或燃料。 相似文献