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221.
222.
印度板块北边界地震活动和中国大陆地震 总被引:17,自引:8,他引:17
本文研究了印度板块北边界地震活动与我国大陆地震活动的关系,给出了两者在时间起伏上的一致性,以及印度板块北边界兴都库会和缅甸两端点附近中深地震对中国大际强震活动所具有的前兆性和相关性。这些特点,对于中国大陆强震活动的预测,尤其是地震大形势预测是十分有意义的。文中还应用了中国大陆强震孕育发生的计算机模型的研究结果,讨论了强震活动的时空分布特征,对于理解中国大陆作为一个孕震系统在周围地质构造块体动力作用 相似文献
223.
丹江口水库及邻区地震震源参数研究 总被引:5,自引:0,他引:5
在讨论震源参数和M震级关系以及论述利用地方震尾波估算地震矩方法的基础上,尝试性地系统估算了丹江口水库及邻区内43次ML≥2.5级地震的震源参数,并讨论了丹江口水库地震的特征。丹江口水库及邻区地震震源参数的初步分析表明:丹江口及邻区属低应力降地区。水库蓄水的附加引张应力效应可能使得丹江口水库中局部以引张应变为主的地区应变迅速增加,地震应力降高于该区一般地震原有水平、从而诱发地震。此外,丹江口水库地震的破裂长度可能和震源机制的破裂类型有关。 相似文献
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用两种加载方式对岩石的破裂进行了实验研究。一种方式是在一定的围压下增加轴压使岩石破裂(A型);另一种方式是在一定围压下增加轴压直到破裂前某一应力状态,然后停止加轴压转而减小围压使岩石破裂(B型)。所用的岩石样品为济南辉长岩和山东掖县白大理岩。着重研究应力途径对岩石脆性-延性变化的影响。辉长岩在1.5千巴以下两种应力途径下的破裂都表现为脆性,但是对于同样的应力状态,B型实验比A型实验显得更脆。随着围压增加到200-250巴之间,大理岩由脆性转变为延性。围压250巴以上,大理岩的A型实验发生延性破裂。样品承受载荷的能力是逐渐丧失的。破裂过程中声发射率极低,听不到破裂声响。最后在样品中形成了剪切断面,但破裂很慢。然而,在大理岩的B型实验中,围压在250巴以上发生了脆性破裂,其表现为轴向应力突然下降,伴随着脆性破裂的声响并有声发射率剧增的前兆。看来,B型应力途径对岩石起了一个脆化的作用。 相似文献
226.
本文通过对纯烃类化合物——正十八烷的动力学模拟实验,阐述了正十八烷裂解过程中气态烃组分及其同位素的演化特征,获得了产自正十八烷的甲烷生成动力学参数。运用动力学参数将模拟实验结果外推到地质条件下,表明由烷烃裂解形成的甲烷主要生成于150~200C(Easy%Ro介于1.0%~2.0%)的范围,裂解产生的甲烷、乙烷、丙烷的碳同位素分馏效应与Easy%Ro的关系曲线受升温速率的影响,不能直接应用于地质条件。 相似文献
227.
四川丹巴白云母矿山公园矿业遗迹资源特征及评价 总被引:1,自引:0,他引:1
四川丹巴白云母矿是我国开发最早的白云母矿之一。在悠久的开采历史中遗存下了十分丰富的矿业遗迹,成为该公园建设的基础。这些遗迹典型、稀有,系统完整,科学价值高,组合独特,具有很高的历史文化价值。此外,公园内配套的自然人文景观丰富,旅游区位条件良好,矿业遗迹开发价值巨大。 相似文献
228.
Origin of natural sulphur-bearing immiscible inclusions and H2S in oolite gas reservoir, Eastern Sichuan 总被引:1,自引:0,他引:1
Liu Dehan Xiao Xianming Xiong Yongqiang Geng Ansong Tian Hui Peng Pingan Shen Jiagui Wang Yunpeng 《中国科学D辑(英文版)》2006,49(3):242-257
Based on results of microscopic observation and laser Raman analysis about fluid inclusions, multiple special forms of immiscible
inclusions that contain sulphur, liquid hydrocarbon, bitumen, etc. were discovered in samples collected from the H2S gas reservoir-containing carbonates in the Lower Triassic Feixianguan Formation in the Jinzhu-Luojia area, Kai County, Sichuan
Province. Based on the lithology and burial history of the strata involved as well as measurement results of homogenization
temperature of fluid inclusions, bitumen reflectivity, etc., it is concluded that the H2S in the gas reservoir resulted from the thermal reaction between hydrocarbons in reservoir and CaSO4 in the gypsum-bearing dolostone section at the high temperature (140°C–17°C) oil-cracked gas formation stage in Late Cretaceous.
Thereafter, research on a great number of immiscible inclusions in the reservoir reveals that elemental sulphur resulted from
oxidation of part of the earlier-formed H2S and further reaction between sulphates, hydrocarbons and H2S in geological fluids in H2S-bearing gas reservoir at a temperature of 86°C–89°C and a pressure of 340×105Pa and during the regional uplift stage as characterized by temperature decrease and pressure decrease in Tertiary. Meanwhile,
gypsum, anhydrite and calcite formed at this stage would trap particles like elemental sulphur and result in a variety of
special forms of immiscible inclusions, and these inclusions would contain information concerning the complexity of the fluids
in the reservoir and the origin of H2S and natural sulphur in the gas reservoir. 相似文献
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Soil respiration is a key component of the global terrestrial ecosystem carbon cycle. The static opaque chamber method was used to measure the CO2 effluxes from soil of a semiarid Aneurolepidium chinense steppe and a Stipa krylovii steppe in the Xilin River Basin of Inner Mongolia, China from March 2002 to December 2004. The results indicated that the soil respiration rates of the semiarid Aneurolepidium chinense steppe and the Stipa krylovii steppe were both relatively high from mid-May to mid-September of each year and remained low during the rest of the year. The minimum value of soil respiration occurred in December or January and negative effluxes of CO2 appeared for several days during the non-growing season of individual years at the two sampling sites. A high annual variation was found in the two steppes with the coefficients of variance (CV) being over 94%, even high to 131%. The annual sums of soil CO2 efflux of the Aneurolepidium chinense steppe varied between 356.4 gC m?2 yr?1 and 408.8 gC m?2 yr?1, while those of the Stipa krylovii steppe in the three years were in the range of 110.6 gC m?2 yr?1 to 148.6 gC m?2 yr?1. The mean respiration rates of the Aneurolepidium chinense steppe were significantly higher than those of the Stipa krylovii steppe in different statistical periods with the exception of the non-growing season. About 59.9% and 80.6% of the soil respiration variations in both steppes for the whole sampling period were caused by the changes of temperature and soil water content. In the Aneurolepidium chinense steppe, the soil respiration rate has significant or extremely significant positive correlation (r = 0.58 ? 0.85, p < 0.05 or p < 0.01) with air temperature and ground temperature of the topsoil except in 2002; the unique contributions of temperature change to the soil respiration variation of the three years were 53.3%, 81.0% and 58.6%, respectively. But, for the Stipa krylovii steppe in the same time interval, the soil water content (especially that of the 10–20 cm layer) has a greater effect on the change of soil respiration, and the unique contributions of the change of the 10–20 cm soil water content to the variations of soil respiration in 2002 and 2003 were 60.0% and 54.3%, respectively. In 2004, in spite of the higher contribution of temperature than soil water content, the contribution of ground temperature at a depth of 10 cm was only 46.2%, much weaker than that of any single year in the Aneurolepidium chinense steppe. 相似文献