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231.
本文简要介绍了InSAR及其差分技术的基本原理,并以仲巴地震为例,采用已知DEM的二路差分法获取了仲巴地震的同震形变场。结果表明:仲巴地震为是一个以倾滑为主的浅源正断层型地震,断层面走向近乎南北方向。 相似文献
232.
233.
Geological and geotechnical investigations of Loharinag-Pala Hydroelectric Project,Garhwal Himalaya,Uttarakhand 总被引:1,自引:0,他引:1
Ajay K. Naithani A. K. Bhatt K. S. Krishna Murthy 《Journal of the Geological Society of India》2009,73(6):821-836
The project area, forming a part of Bhagirathi valley, exposed rocks classed as central Himalayan crystallines and are medium
to high grade metamorphics. The rock types exposed are feldspathic gneisses, quartz-biotite schists, garnet-biotite schist,
biotite gneisses, migmatites and amphibolites. To design the rock support for the underground structures of desilting chambers,
HRT, surge shaft, pressure shafts, power house, TRT and for the foundations of barrage and intake of desilting chambers, rock
mass classifications was attempted following the methods of Bieniawski Rock Mass Rating (RMR) Classification and Tunnelling
Quality Index (Q) of Barton et al. RMR technique involves collection of data on rock strength, RQD (%), spacing of discontinuities,
condition of discontinuities and groundwater condition, while the ‘Q’ involves collection of data on RQD (%), joint set numbers
(Jn), joint roughness number (Jr), joint alternation number (Ja), joint water reduction factor (Jw) and stress reduction factors
(SRF). The permeability test in the overburden was done by the constant head method, while in the bed rock portion conducted
by packer test. The result indicates that the rock masses of the area fall under the good, fair and poor rock quality. Augen
gneiss of power house area is coming under the category of moderately strong rock as proved by deformability characteristics
and strength parameter. On the basis of above study recommendations have been made for the proper and safe construction of
the project components. 相似文献
234.
Groundwater level and chemistry changes resulting from tunnel construction near Matsumoto City, Japan 总被引:3,自引:0,他引:3
Before tunnel construction began, the groundwater chemical compositions and levels around the tunnel were studied to determine
if water compositions could predict whether surface water will be influenced by tunnel construction. When the chemical composition
of the well and springwater was similar to that of the tunnel seepage water, and the altitude of the well and spring was above
the tunnel level, the groundwater level in the well and spring was influenced by draining tunnel seepage water. Therefore,
comparing the chemical compositions of surface water and groundwater may be used for predictive purposes. However, the results
of this study showed there was no noticeable chemical composition change in springwater prior to changes in groundwater level
at a particular site. The changes in the hydrology of the plateau caused by tunnel construction were also studied, using measurements
of the changes in groundwater chemistry as well as changes in groundwater levels. Prior to tunnel construction, river discharge
was greater. Following tunnel construction, some river discharge decreased because springwater was drained as tunnel seepage
water and the spring in the catchment dried up. Tritium concentration indicated that 3 years after tunnel construction, surface
water did not reach tunnel levels in spite of groundwater level lowering and remaining unconfined groundwater being drained.
Received: 17 January 1996 · Accepted: 10 July 1996 相似文献
235.
236.
On the use of the capability polar plots program for dynamic positioning systems for marine vessels 总被引:2,自引:0,他引:2
As the capability of polar plots becomes better understood, improved dynamic positioning (DP) systems are possible since the control algorithms greatly depend on the accuracy of the aerodynamic and hydrodynamic models. The measurements and estimation of the environmental disturbances have an important role in the optimal design and selection of a DP system for a marine vessel. The main objective of this work is to present a new software program capable of estimating the environmental forces, thrusters capability calculations, and capability polar plots for marine vessels. A flowchart illustrating the logic and data flow of a developed software program, the Capability Polar Plot Program (CPPP), and the estimated results for two case studies for a scientific drilling vessel and a survey vessel are presented. It is obvious from the obtained results that the developed program has a future potential for the estimation of the Capability Polar Plots for marine vessels. Moreover, the developed software program would be considered as a marine tool for the thrusters' selection and their configuration for marine vessels and floating production units for the Oil and Gas industries. 相似文献
237.
1 INTRODUCTION Tunnel erosion or piping is very common in semi-arid areas. It is often associated with gully system development (e.g., Parker, 1965; Heede, 1971; Harvey, 1982; Crouch, 1983; Gutierrez et al., 1997). It may also become a severe soil conserv… 相似文献
238.
世界第一高隧青藏铁路风火山隧道施工新技术 总被引:5,自引:1,他引:5
高原、严寒条件下的青藏铁路风火山隧道施工, 在永久冻土区隧道施工技术、合理支护结构形式以及人员健康等方面提出了严峻挑战。采用适用高原严寒条件下的施工方案, 综合利用、保护冻土围岩的隧道施工方法和独特的通风、供暖、供氧和供水等辅助施工作业措施, 并结合施工技术研究, 保证了隧道施工的顺利进行。 相似文献
239.
240.
长江三峡中坝遗址是我国目前仅有的、世界上也罕见的“通史式”遗址。它不仅蕴藏大量的文化内涵,而且包含极其丰富的自然环境演变信息,是研究三峡地区全新世环境演变的理想剖面。文章对遗址地层中的铷(Rb)、锶(Sr)值进行了测试和分析,结果显示:剖面地层中的Rb含量偏低,而Sr含量偏高,Rb/Sr比值变化较大。Rb/Sr比值已成为区域环境演变研究中较理想的替代指标,根据Rb/Sr比值的环境指示意义发现,长江三峡地区全新世中晚期以来气候环境总体上逐渐趋于恶劣;气候冷暖湿热变化剧烈;寒冷期长于温暖期,并没有明显地向湿热方向发展趋势。与长江下游等东部其他地区相比,长江三峡地区也存在明显不同之处:隋唐暖期不明显,而中世纪暖期表现显著。 相似文献