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101.
近年来,有害藻华频繁发生给海洋生态系统甚至人类健康带来严重影响。伊姆裸甲藻(Gymnodinium impudicum)是一种典型有害藻华原因种,开展其溶藻菌筛选工作,将有利于该种藻华的防控研究。本研究从伊姆裸甲藻藻华发生海域,分离一株针对藻华原因种的溶藻菌LD B3,16S rDNA序列分析表明,该菌株属于假交替单胞菌属(Pseudoalteromonas)。菌藻共培养结果显示,2.0%终浓度LD B3菌液添加72 h后,伊姆裸甲藻溶藻率达81.06%,且溶藻效应呈现浓度和时间依赖性。显微观察和生理参数测定结果表明,菌株LD B3可导致伊姆裸甲藻细胞链断裂,最大光合效率(Fv/Fm)下降。溶藻方式研究发现,菌株LD B3主要通过分泌胞外物质实现溶藻,且这类物质对温度较为敏感,初步推断其可能为蛋白类物质。本研究结果表明菌株LD B3在伊姆裸甲藻溶藻剂开发方面有一定应用前景。  相似文献   
102.
Based on a comparison of similar colour indices we investigate the effects of luminosity and metallicity that influence the Strömgren and Vilnius photometric quantities for different spectral types. We notice significant differences for similar indices, apparently due to small deviations of central wavelengths and band-widths of the filters. For the G-K type stars of moderate luminosity we interpret the difference introduced by v and X pass-bands as an log g effect, reflecting the presence of H&;K Ca II stellar lines in these spectral types. We discuss a possible influence of the H&;K Ca II lines on the luminosities derived from the Vilnius classification diagrams.  相似文献   
103.
乔欣  胡煜昭  江小均  陆俊吉 《地质通报》2016,35(11):1884-1894
新疆萨热克含铜盆地库孜贡苏组是复合型冲积扇沉积相,是重要的赋矿层。利用研究区24个钻孔和10个露头剖面资料,运用高分辨率层序地层学原理进行单孔沉积相、连孔沉积相、平面沉积相分析,对新疆萨热克含铜盆地库孜贡苏组(J3k)复合型冲积扇内部垂向和3个中期旋回期间沉积相亚相的平面分布特征进行了研究。研究表明,该区库孜贡苏组垂向分布大体可分为3个中期基准面旋回和若干短期基准面旋回,据此建立了高分辨率层序地层对比格架。3个中期旋回期间,沉积亚相平面发育模式差异大。铜矿(化)体垂向、平面分布特征明显。  相似文献   
104.
The attainment of suitable ambient air quality standards is a matter of great concern for successfully hosting the XXIV Olympic Winter Games (OWG). Transport patterns and potential sources of pollutants in Zhangjiakou (ZJK) were investigated using pollutant monitoring datasets and a dispersion model. The PM2.5 concentration during February in ZJK has increased slightly (28%) from 2018 to 2021, mostly owing to the shift of main potential source regions of west-central Inner Mongolia and Mongolian areas (2015–18) to the North China Plain and northern Shanxi Province (NCPS) after 2018. Using CO as an indicator, the relative contributions of the different regions to the receptor site (ZJK) were evaluated based on the source-receptor-relationship method (SRR) and an emission inventory. We found that the relative contribution of pollutants from NCPS increased from 33% to 68% during 2019–21. Central Inner Mongolia (CIM) also has an important impact on ZJK under unfavorable weather conditions. This study demonstrated that the effect of pollution control measures in the NCPS and CIM should be strengthened to ensure that the air quality meets the standard during the XXIV OWG.  相似文献   
105.
On 22 September 2020, within the backdrop of the COVID-19 global pandemic, China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060. This carbon-neutral goal is generally considered to cover all anthropogenic greenhouse gases. The planning effort is now in full swing in China, but the pathway to decarbonization is unclear. The needed transition towards non-fossil fuel energy and its impact on China and the world may be more profound than its reform and development over the past 40 years, but the challenges are enormous. Analysis of four representative scenarios shows significant differences in achieving the carbon-neutral goal, particularly the contribution of non-fossil fuel energy sources. The high target values for nuclear, wind, and bioenergy have approached their corresponding resource limitations, with solar energy being the exception, suggesting solar’s critical role. We also found that the near-term policies that allow for a gradual transition, followed by more drastic changes after 2030, can eventually reach the carbon-neutral goal and lead to less of a reduction in cumulative emissions, thus inconsistent with the IPCC 1.5°C scenario. The challenges and prospects are discussed in the historical context of China’s socio-economic reform, globalization, international collaboration, and development.  相似文献   
106.
The Fukusen No. 1 vein is located in the southeastern part of the Yamada deposit, Hishikari epithermal gold deposits, southern Kyushu, Japan. 40Ar/39Ar plateau ages of adularia from the margin and the center of the Fukusen vein are determined to be 0.617 ± 0.024 Ma and 0.606 ± 0.009 Ma, respectively. The Fukusen No. 1 vein shows banding structure composed mainly of quartz, adularia and clay minerals. Colloform texture is displayed by cryptocrystalline to amorphous silica material that is associated with fine-grained electrum and sulfides near the center of the vein. Pyrite in the Fukusen No. 1 vein often shows acicular shape resulting from inversion from marcasite. Near the center of the vein, primary marcasite occurs associated with colloform texture of silica. The Fukusen No.1 vein preserves primary texture and materials which were deposited from the ore-forming hydrothermal solution. The Fukusen No. 1 vein was formed in a short period and is one of the youngest veins in the Hishikari deposits.  相似文献   
107.
Black carbon (BC) concentrations were measured in the southeast (SE) Tibetan Plateau along the valley of the Yarlung Tsangpo River during winter (between November, 2008 and January, 2009). The measured mean concentration (0.75 μg m−3) is significantly higher than the concentrations (0.004–0.34 μg m−3) measured in background and remote regions of the globe, indicating that Tibetan glaciers are contaminated by BC particles in the Plateau. Because BC particles play important roles for the climate in the Tibetan Plateau, the sources and causes of the BC contamination need to be understood and investigated. In this study, a mesocale dynamical model (WRF) with BC particle modules is applied for analyzing the measurement. The analysis suggests that the major sources for the contamination in the SE Plateau were mainly from the BC emissions in eastern Indian and Bangladesh. Because of the west prevailing winds, the heavy emissions in China had no significant effects on the SE Plateau in winter. Usually, the high altitude of the Himalayas acts a physical wall, inhibiting the transport of BC particles across the mountains to the plateau. This study, however, finds that the Yarlung Tsangpo River valley causes a 'leaking wall', whereby under certain meteorological conditions, BC particles are being transported up onto the glacier. This too causes variability of BC concentrations (ranging from 0.3 to 1.5 μg m−3) in a time scale of a few days. The analysis of the variability suggests that the “leaking wall” effect cannot occur when the prevailing winds were northwest winds, during which the BC transport along the valley of the Yarlung Tsangpo River was obstructed. As a result, large variability of BC concentration was observed due to the change of prevailing wind directions.  相似文献   
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110.
The flattened or elongated morphology often observed in contact twinned crystals has been referred to the so-called re-entrant corner effect at twin junctions. To re-investigate the validity of this mechanism, natural quartz crystals twinned after Japan Law have been subjected to re-growth in a commercial synthetic quartz autoclave, and the change in their morphology and surface microtopography by re-growth studied. It is found that although twin re-entrant corners may play a role of preferential growth sites, this role can be weakened considerably and in fact can become almost negligible when crystals grow under high supersaturation condition. Preferential growth at the re-entrant corner of a twin junction is probably due to clusters of dislocations concentrated in the composition plane, and not due to the so-called re-entrant corner effect in its original sense.  相似文献   
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