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41.
Microbial Biomass Dynamics Along a Trophic Gradient at the Atlantic Barrier Reef off Belize (Central America) 总被引:2,自引:0,他引:2
Abstract. Recent findings indicate that heterotrophic bacteria and not phytoplankton are the most numerous biomass components even in the euphotic zone of oligotrophic, open oceans. In this study it was hypothesized that the microbial biomass components change within a few hundred meters as oligotrophic water flows across the reef and becomes enriched with nutrients. Along a trophic gradient, four stations at the Atlantic Barrier Reef off Belize (Central America) were sampled for microbial biomass components. Phytoplankton biomass (measured as chlorophyll a) ranged from the most oligotrophic station (St. 1) to the most eutrophic station (St. 4) from 6.9–415.5 μg CI"' (assuming a C:chl a ratio of 30): heterotrophic bacterial biomass increased 4-fold (from 10.1–46.4μg C 1-1 ), heterotrophic nanoflagellate (HNAN) biomass increased from 4.6-19ug C 1-1 , and cyanobacteria from 0.9-4.5 μg C-1-1 . Production estimates derived from seawater cultures revealed a 5-fold increase in bacterial production from the oligotrophic station (3.7 ug C 1-1 d-1 ) to the eutrophic St. 4 (17.8ug C-1-d1-1 )- Cyanobacterial production rose from 1.1–3.5ug C-1–d-1 and HNAN production from 0.65-1.13 μg C-1-1 -d-1 . While cyanobacteria contributed between 13 and 20% to the autotrophic plankton component in the oligotrophic waters, their contribution dropped to about 1 % at the eutrophic stations. 相似文献
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44.
Marine manganese nodules and crusts, when processed, yield tailings which may be utilized for environmental and economic benefit. The key to the reasonable and effective utilization of these tailings lies in making a systematic appraisal of their composition and properties. This article gives an introduction to the investigation of manganese tailings properties. The tailings have a high iron and/or manganese content, high surface area, high porosity, and fine grain size. Some tailings have a high rare earth element content which is valuable. They may also have high SO3, arsenic, and uranium contents which are harmful. Depending on the process used to produce the tailings, there will likely be some differences in chemical composition, mineral assemblages, surface area and adsorption capability, pore diameter and volume, density and pH. In assigning potentially beneficial applications for these tailings, these differences should be taken into account to optimize utilization. 相似文献
45.
海洋木栖真菌抗菌活性的初步研究 总被引:6,自引:0,他引:6
从福建厦门海沧、集美及漳州浮宫等地采集到的红树林等海洋潮间带的各种腐木样品中分离得到176株海洋木栖真菌,对其进行抗菌活性检测.其结果表明共有96株海洋木栖真菌对大肠杆菌、枯草杆菌及白色假丝酵母中的一种或多种拮抗指示菌具有抑制作用,占供测菌株总数的54.5%.在这些活性菌株中,红树源菌株拮抗比例为30.2%,非红树源菌株拮抗比例为69.8%.具有抗菌活性的菌株主要分布于15个属中,包括木霉Trichoderma、青霉Penicillium、拟青霉Paecilomyces和一些不产孢的分类群.某些稀有真菌如盘多毛孢Pestalotia、茎点霉Phoma也具有一定的抗菌活性. 相似文献
46.
坛紫菜(于1988年采自青岛太平角海区人工养殖筏上)的水溶性色素粗提物经过硫酸铵沉淀和羟基磷灰石(HA)柱层析后,分离出藻蓝蛋白(RPC)、藻红蛋白(RPE)和变藻蓝蛋白(APC)。在中性介质中,其吸收光谱和荧光发射光谱与文献报道基本一致;但在酸性(pH=3)或碱性(pH=12)介质中,吸收光谱较在中性介质中有明显改变,原有的荧光性质也消失。RPC和APC只分离到一种聚集体,但RPE有两种不同的聚集体。用SephadexG—100凝胶过滤方法测量藻胆蛋白的分子量分别为:RPC117000,APC112000,小分子RPE38000,大分子RPE232000。对三种藻胆蛋白的氨基酸分析的结果表明,三种藻胆蛋白中都是酸性氨基酸的含量大于碱性氨基酸的含量。 相似文献
47.
台湾南湾秋末冬初水螅水母类的组成与分布 总被引:4,自引:0,他引:4
本文分析了2001年11月2~3日和12月8~10日在台湾南湾12个测站采集的表层和底层92份浮游动物样品,共鉴定水螅水母18种,其中8种是台湾周围海域的新记录.半口壮丽水母(Aglaura hemistoma)和四叶小舌水母(Liriope tetraphylla)为优势种,它们在11月和12月分别占水螅水母类总量的77%和94%以上.南湾水螅水母类的种类数和个体丰度均以12月(17种,3102×10~(-3)个/m~3)明显多于11月(6种,72×10~(-3)个/m~3).在冬季,外海高盐水团是影响水螅水母类分布的主要因素,盐度与水螅水母类多样性指数的相关关系显著,文章还比较了南湾与邻近海区水螅水母类的季节变化. 相似文献
48.
Natalia V. Zhukova 《Ocean Science Journal》2005,40(3):34-42
Variation in the microbial biomass and community structure found in sediment of heavily polluted bays and the adjacent unpolluted
areas were examined using phospholipid fatty acid analysis. Total microbial biomass and microbial community structure were
responding to environmental determinants, sediment grain size, depth of sediment, and pollution due to petroleum hydrocarbons.
The marker fatty acids of microeukaryotes and prokaryotes - aerobic, anaerobic, and sulfate-reducing bacteria -were detected
in sediments of the areas studied. Analysis of the fatty acid profiles revealed wide variations in the community structure
in sediments, depending on the extent of pollution, sediment depth, and sediment grain size. The abundance of specific bacterial
fatty acids points to the dominance of prokaryotic organisms, whose composition differed among the stations. Fatty acid distributions
in sediments suggest the high contribution of aerobic bacteria. Sediments of polluted sites were significantly enriched with
anaerobic bacteria in comparison with clean areas. The contribution of this bacterial group increased with the depth of sediments.
Anaerobic bacteria were predominantly present in muddy sediments, as evidenced from the fatty acid profiles. Relatively high
concentrations of marker fatty acids of sulfate-reducing bacteria were associated with organic pollution in this site. Specific
fatty acids of microeukaryotes were more abundant in surface sediments than in deeper sediment layers. Among the microeukaryotes,
diatoms were an important component. Significant amounts of bacterial biomass, the predominance of bacterial biomarker fatty
acids with abundance of anaerobic and sulfate-reducing bacteria are indicative of a prokaryotic consortium responsive to organic
pollution. 相似文献
49.
50.
厦门东海域定置网渔获鱼类种类组成及其季节变化 总被引:7,自引:1,他引:7
2003年7月~2004年6月对厦门东部海域的定置网渔获鱼类进行采样分析.结果表明厦门东海域至少有鱼类242种,隶属于19个目81科145属,主要是沿岸近底层和底栖的小型鱼类.以鲈形目种类最多,共计127种,占总数的52.5%、经济种类有116种.主要优势种有:青鳞小沙丁鱼、孔鳞小沙丁鱼、斑鲦、马拉邦虫鳗、裸鳍虫鳗、中华须鳗、前鳞鲻、眶棘双边鱼、多鳞鳝、皮氏叫姑鱼、短棘银鲈、列牙垒幸4、黄斑蓝子鱼、褐蓝子鱼、锯塘鳢、锻虎鱼类、褐菖鲇、绿鳍鱼、鳄鲡、卵鳎、中华单角鲍等.渔获种类在秋季及冬初最多,夏季较多,而冬末和春初最少.渔获种类的季节变化比较明显,与海洋表层水温变化有关,种类的月更替率比较高. 相似文献