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121.
地震反射波检测煤层厚度的直接反演方法 总被引:3,自引:0,他引:3
为适应矿井建设时采区地震勘探检测煤层厚度的需要,从煤层具有地震勘探中"薄层"特点出发,建立煤层反射波数学表达式在频率城直接反演,并采用可减少非煤厚因素影响的谱平方比法检测煤厚,取得良好效果,可达到煤矿建设要求。 相似文献
122.
Yong Zhang Tao Yang Junbo Zhang Baoyi Lv Xiangsheng Cheng Yin Fang 《中国海洋大学学报(英文版)》2020,19(3):633-642
The Sanchi oil tanker collision in the East China Sea on January 6th, 2018 has caused worldwide attention due to its uniqueness. A considerable amount of h 相似文献
123.
对济南市2013年1—12月的能见度、相对湿度、PM10及PM2.5逐时监测数据分析,结果表明:能见度、相对湿度、PM10和PM2.5浓度有明显的月变化和日变化规律。在各项污染物中,能见度与颗粒物的相关性最高,与PM10的相关系数为-0.6718,与PM2.5的相关系数为-0.7422;在气象因子中,与相对湿度的相关性最高,相关系数为-0.6501。不同季节条件下,能见度与PM2.5的相关性明显优于PM10的,冬季能见度与颗粒物的相关性明显优于其他季节的。 相似文献
124.
Yin Jiabo Guo Shenglian Yang Yan Chen Jie Gu Lei Wang Jun He Shaokun Wu Boyang Xiong Jinghua 《中国科学:地球科学(英文版)》2022,65(9):1772-1787
Science China Earth Sciences - Global warming has altered the thermodynamic and dynamic environments of the climate system, thus affecting the energy budget and water cycle process of the... 相似文献
125.
Investigated is the coupled response of a tension leg platform (TLP) for random waves. Inferred are the mass matrix, coupling stiffness matrix, damping matrix in the vibration differential equation and external load of TLP in moving coordinating system. Infinitesimal method is applied to divide columns and pontoons into small parts. Time domain motion equation is solved by Runge-Kutta integration scheme. Jonswap spectrum is simulated in the random wave, current is simulated by linear interpolation, and NPD spectrum is applied as wind spectrum. The Monte Carlo method is used to simulate random waves and fluctuated wind. Coupling dynamic response, change of tendon tension and riser tension in different sea conditions are analyzed by power spectral density (PSD). The influence of approach angle on dynamic response of TLP and tendon tension is compared. 相似文献
126.
127.
茅排金矿床属中-低温硫化物金矿床,矿体的分布严格受断裂构造控制.通过应用不同的物探方法来寻找控矿断裂,从而达到间接地寻找矿体分布的目的,取得了较好的效果。 相似文献
128.
129.
本文研究了直接测定海洋河弧菌 (vibrio fluvailis) 5 10脂多糖的分光光度法。利用 1,9-二甲基亚甲蓝 (DMB) ,在适当条件下同脂多糖发生染色反应 ,在 5 5 0 nm波长下 ,反应体系的吸光值同脂多糖含量呈线性相关。相关系数为 0 .9993,最低检出限为 10 μg/m L,相对标准偏差为 1.6 2 ,平均回收率为 (10 5± 2 .18) %。 相似文献
130.
To restore China’s degraded ecological environment, the government has launched an environmental restoration project named
the “Grain for Green Project” (GGP) in 1999. From 1999 to 2010, the government will spend 40 billion dollars to convert 147
million ha of croplands and 173 million ha of wastelands into forestlands and grasslands in 25 provinces, municipalities and
autonomous regions. A primary goal is to replace cropping and livestock grazing in fragile areas with trees and grass. Given
the tremendous scale and great number of participants in the project, the attitudes of the affected farmers and the future
development in the area where GGP is implemented have a direct influence on the success of the project. To gain a clear idea
about the farmers’ attitudes towards the project and put forward the development models for the forestlands converted from
croplands, two case sites in the mountain-gorge region in Nujiang River are selected as the study areas, and the methods of
field survey and semi-structured interview are adopted to make interviews with more than 100 households in 2002 and 2003 in
order to quantify the farmers’ opinions about the GGP and how it has affected their livelihood, socio-cultural and industrial
structures, etc. The results are as follows: 1) the project has a certain influence on the farmers with better economic basis
and exerts greater influence on the farmers living in the low-elevation regions than on those living in the regions with middle-high
elevation; 2) the production models of the local farmers has changed from cultivation and animal husbandry to forestry and
sidelines due to the project and the income structure has changed from animal husbandry as main income source to state subsidy
and sideline as main income sources; 3) the reduction in the grain income and decrease in the quantity of livestock because
of the project have led to the diminution in the total income of the farmers; 4) the project has resulted in changes in the
lifestyles and architecture styles of the local farmers, and the traditional “huotang” culture has gone away after the implementation
of the project; 5) energy utilization has changed from firewood to methane and electricity in the wake of the implementation
of the project. The above-mentioned study results have indicated that the GGP has truly exerted influence on the livelihood
and production of the local farmers. Therefore, it is very necessary to make a research into the development models in the
forestlands converted from croplands to resolve the problems of the farmers’ livelihood and production. The study results
will provide some references for the sustainable development of the mountain-gorge regions. 相似文献