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971.
It is well known that L andsat TM im ages and remote-sensing data sets are widely used in the geological fields.There are7different bands of wavelength,of which the sixthone has a much lower ground resolution compared with thoseof the other six bands.Nevertheless,the L andsat TM imagesare of important significance of the rock spectrum reflectionand geothermal exploration.The raising of the ground resolu-tion of TM band6 to those of the other bands is not only in-teresting but also valuable.… 相似文献
972.
用古植被面貌重建桂林3. 7万年以来的气候变化 总被引:3,自引:0,他引:3
末次冰期自37kaB. P.以来至9kaB. P.时段内,对桂林一带的影响主要是降温及降雨量减少,平均气温最低7~ 9℃ ,比现今低10~12℃ ,其间虽有波动,但未发现有冰川的证据。9~ 8kaB. P. ,桂林气候发生突变,在1ka 的时间内,平均气温的变化幅度达12~ 13℃ ; 8kaB.P. 时桂林年均气温升至21~ 22℃ ,比现今高2~ 3℃ ; 3. 69kaB. P. 时,气温升到最高,年均气温达22~ 23℃ ,比现今高3~ 4℃ ,年均降雨量也相应发生一定的变化 相似文献
973.
福建物探、化探工作起步于20世纪50年代。近半个世纪以来,福建省地质工作者利用物探、化探、遥感等技术在区域地质,深部地质,矿产地质,水文地质、工程地质,环境地质,医学地质,农业地质等领域取得了丰硕成果,但还存在一定差距。为进一步提高福建省物探、化探、遥感等技术水平和扩大应用领域,对今后工作提出几点建议和对策。 相似文献
974.
Combined effects of heavy metal and polycyclic aromatic hydrocarbon on soil microorganism communities 总被引:2,自引:0,他引:2
Soil contaminated sites contain a variety of pollutants, especially heavy metals and polycyclic aromatic hydrocarbons (PAHs).
Interactions between heavy metals have been relatively well studied, but little is known about interactions between heavy
metals and PAHs. The combined effect of heavy metals and PAHs on soil microorganism was studied in laboratory conditions and
evaluated by random denaturing gradient gel electrophoresis. We extracted DNA directly from contaminated soils and then amplified
the V3 sequences of the 16S rDNA. The results showed that with different culture time, the gene diversity of the single and
combined contaminated soil differed as well. After 15 days of culture, the microorganisms were stimulated and accommodated.
After 45 days of cultivation, the quantities of the soil microorganisms were affected. It is concluded that some of the microorganisms
utilize phenanthrene as important carbon resources. Microorganisms directly isolated from soil could reflect the diversity
of soil microorganism and population distribution conditions. 相似文献
975.
基体效应校正是 X射线荧光分析方法中关键的一环 ,在很大程度上决定了测量数据的准确度。本文提出了一种新的基体效应校正方法—准绝对测量方法。它兼有相对测量和绝对测量方法的特点 ,并具有较广泛的适用性 相似文献
976.
ABSTRACTThe Suyunhe porphyry Mo deposit, located in the West Junggar terrane, is the largest molybdenum deposit found in Xinjiang to date, with a proven reserve of 0.57 Mt. The Suyunhe deposit is associated with Early Permian granitic rocks, which emplaced into the volcano-sedimentary sequences of the Middle Devonian Barluk Formation. Four metallogenic stages are identified in this study. Stage I is marked by the quartz-magnetite-K-feldspar±biotite±pyrite±molybdenite veins, which mainly occurred in the intensively potassic alternation zone and were formed at high temperature (>481°C), high salinity (58.6?65.18 wt.%), and relatively high oxygen fugacity conditions with a fluid system of NaCl-H2O-CO2. Stage II is the main metallogenic stage and develops numerous quartz-molybdenite±pyrite veins associated with muscovite–chlorite alteration, which were formed by immiscible fluids at medium-high temperature (210?427°C), medium-high salinity (43.36?49.90 wt.%), and relatively low oxygen fugacity conditions with the fluid system of NaCl-H2O-CO2-CH4-C2H6. After the main Mo-mineralization, quartz-polymetallic sulphides veins associated with quartz–sericite alteration were formed by fluids at medium-low temperature, low-salinity conditions with the fluid system of NaCl-H2O-CO2 in stage III. The following quartz-polymetallic sulphide veins are quartz-calcite±pyrite veins associated with calcite alteration, which were formed by fluids at low temperature and low-salinity conditions with a fluid system of NaCl-H2O in stage IV.The δ18O‰ values indicate that the ore fluids of stages I and II are dominated by magmatic water, whereas stages III and IV are dominated by meteoric water. A wide range of δ34S‰ values (?7.1 to 3.4‰) of sulphides between stages I and II indicates that increasing the reducibility plays an important role in molybdenum mineralization. The δ13CCH4 values suggest that CH4 of the ore fluids mainly results from the assimilation–contamination of carbonaceous country rocks, and partly derives from magma. However, the δ13CCO2 values suggest that CO2 of the ore fluids mainly originates from magma, and minor derives from wall-rocks as well as meteoric water. 相似文献
977.
The Yitong(伊通) basin is a Late Mesozoic and Cenozoic continental sedimentary basin in Northeast China.On the basis of well tests and seismic data,we use the 2D modeling technique to rebuild the pressure evolution and hydrocarbon migration in the Moliqing(莫里青) fault depression of the Yitong basin.Based on the modeling results,four conclusions are drawn as follows.(1) The Eocene Shuangyang(双阳) Formation within the Moliqing fault depression had entirely undergone three epi-sodic cycles of pressure accumulation... 相似文献
978.
979.
Yu Wang Zijun Cao 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2016,10(4):251-268
In site investigation, the amount of observation data obtained for geotechnical property characterisation is often too sparse to obtain meaningful statistics and probability distributions of geotechnical properties. To address this problem, a Bayesian equivalent sample method was recently developed. This paper aims to generalize the Bayesian equivalent sample method to various geotechnical properties, when measured by different direct or indirect test procedures, and to implement the generalized method in Excel by developing an Excel VBA program called Bayesian Equivalent Sample Toolkit (BEST). The BEST program makes it possible for practitioners to apply the Bayesian equivalent sample method without being compromised by sophisticated algorithms in probability, statistics and simulation. The program is demonstrated and validated through examples of soil and rock property characterisations. 相似文献
980.