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131.
通过对泰安市城区地质环境条件的深入分析,系统阐述了泰安市城市地下空间开发与地质环境因素之间的相互影响关系,一方面城市地下空间开发受到地表水、地下水水位、水质及岩溶塌陷地质灾害等地质环境因素的制约,而地下空间开发建设又反过来影响和改变着城区地下水环境、土壤环境,并有可能提高城区岩溶塌陷发生的机率,因此建议有关部门在规划建设城市地下空间的同时要加强地质环境保护。 相似文献
132.
金刚石钻头的综合评价是一个多指标的决策问题。本文将多指标决策中的TOPSIS法应用于金刚石钻头的综合评价,并用实例与其他方法进行了对比,结果与实际相符。 相似文献
133.
Zircon SHRIMP U‐Pb Dating of the Tourmalinites from Boron‐bearing Series of Borate Deposits in Eastern Liaoning and its Geological Implications 总被引:1,自引:0,他引:1
LIU Jingdang XIAO Rongge ZHANG Yanfei FAN Minghui WANG Shengzhi JIA Yuguo WANG Gang LIU Zhixue 《《地质学报》英文版》2012,86(1):118-130
This paper focused on the zircon sensitive high resolution ion micro-probeU-Pb geochronology of the tourmalinites from boron-bearing series of borate deposits in Eastern Liaoning. The zircons commonly have core-rim structures, most cores show oscillatory zoning in cathodoluminescence and plane polarized light images, suggesting a magmatic detrital origin. Ages of the magmatic detrital zircons from the hyalotourmalite samples (N13) and (N14) are 2175?±?5??Ma and 2171?±?9??Ma, respectively. Moreover, metamorphic zircon from the sample (N13) shows an age of 1906?±?4??Ma. Zircon core and rim from the hyalotourmalite sample (N02) record ages of 2171?±?6??Ma and 1889?±?62??Ma, which are explained as indicating the formation and metamorphic ages. Combined with the geological and geochemical studies, it can be concluded that the tourmalinites are formed during sedimentary exhalative mineralizations in the mid-Paleoproterozoic (~2170?Ma) and underwent the metamorphism in the late-Paleoproterozoic (~1900?Ma). The tourmalinites are the products of submarine acid volcanism in the extension rifting phase of the Liaoji Paleoproterozoic Rift, the rock-forming materials of which are derived from the mantle sources with recycling crustal contamination. The emergence of tourmalinites not only indicates the mid-Paleoproterozoic tectonic-magmatic processes, but also provides impetus, heat and material sources for the mineralization of borate deposits in Eastern Liaoning. 相似文献
134.
通过对全省部分台站月数据文件错情的分析,发现:技术性错误占有很大的比重,有的是对《地面气象观测规范》掌握不够,有的是对月数据文件的记录格式不清楚,有的是对OSSMO2004测报软件掌握不好,有的是对各传感器及采集器的原理、维护缺乏必要的了解等。通过分析月数据文件的错情原因,提出对策,引起测报人员的警惕,以便提高月数据文件的质量。 相似文献
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136.
Wind Conditions in Idealized Building Clusters: Macroscopic Simulations Using a Porous Turbulence Model 总被引:3,自引:0,他引:3
Simulating turbulent flows in a city of many thousands of buildings using general high-resolution microscopic simulations
requires a grid number that is beyond present computer resources. We thus regard a city as porous media and divide the whole
hybrid domain into a porous city region and a clear fluid region, which are represented by a macroscopic k–e{\varepsilon} model. Some microscopic information is neglected by the volume-averaging technique in the porous city to reduce the calculation
load. A single domain approach is used to account for the interface conditions. We investigated the turbulent airflow through
aligned cube arrays (with 7, 14 or 21 rows). The building height H, the street width W, and the building width B are the same (0.15 m), and the fraction of the volume occupied by fluid (i.e. the porosity) is 0.75; the approaching flow
is parallel to the main streets. There are both microscopic and macroscopic simulations, with microscopic simulations being
well validated by experimental data. We analysed microscopic wind conditions and the ventilation capacity in such cube arrays,
and then calculated macroscopic time-averaged properties to provide a comparison for macroscopic simulations. We found that
the macroscopic k–e{\varepsilon} turbulence model predicted the macroscopic flow reduction through porous cube clusters relatively well, but under-predicted
the macroscopic turbulent kinetic energy (TKE) near the windward edge of the porous region. For a sufficiently long porous
cube array, macroscopic flow quantities maintain constant conditions in a fully developed region. 相似文献
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139.
本文利用1960-2001年甘肃省59个气象站的逐日降水资料,统计出汛期(4~9月)各站无雨日数,分析了甘肃汛期无雨日数的基本时空分布特征,并对其标准化后进行经验正交展开(EOF)和旋转经验正交展开(REOF),研究其异常的空间结构及时间演变规律。结果表明;甘肃省汛期无雨日数自东南向西北呈台阶状增加,甘肃汛期无雨日数异常在空间上表现为一致的增多或减少。旋转载荷向量场(RVL)反映出5个无雨日数异常型。旋转主分量(RPC)揭示了42a甘肃汛期无雨日数的时间演变特征,即甘肃中部、陇南、甘南区无雨日数经历了少~多~少的过程,河西为多~少~多的反抛物线型,气候向更干旱化发展,而陇东元雨日数增加趋势较为明显。 相似文献
140.