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排序方式: 共有870条查询结果,搜索用时 15 毫秒
741.
Abdelmalek Bouazza Asadul Haque Dong Mei Wang 《Geotechnical and Geological Engineering》2009,27(1):115-121
The generation of massive volume of slimes from sand mining industry ascertains the need for effective waste treatment. The
application of slimes in landfill barrier construction works has been identified as one of the processes that can be used
to reduce their volume, enabling in this way the rehabilitation of dangerous sites. This article presents a modified triaxial
cell specially built to investigate high water content soils and discusses the results obtained from the investigation of
the hydraulic properties of two slimes. The results of laboratory filter cake tests show that the slimes have reasonably good
sealing capacities due to the formation of a cake layer on other porous materials upon draining. A relatively low hydraulic
conductivity (1.5–3 × 10−9 m/s) was achieved, once the cake layer was formed. This is close to the prescribed 1 × 10−9 m/s required by the local environmental governmental authority for a landfill hydraulic barrier material, indicating their
potential suitability as landfill barrier. 相似文献
742.
PrabhataK.SWAMEE NimishaSWAMEE 《国际泥沙研究》2004,19(1):66-74
The grain size distribution of particulate material is of particular interest in the field of sediment transport. The size distribution is described by various equations, however no equation is flexible enough to satisfy the grain size distribution data faithfully. Presented herein are the equations for unimodal and multimodal grain size distribution curves. A graphical method has been given to evaluate the parameters involved in these equations. The size distribution equation can be used to estimate many properties of sediment sample like number of sediment particles, surface area of the particles and hydraulic conductivity. It is hoped that the equations will find many applications in studying sedimentation processes. 相似文献
743.
Estimation of fault-zone conductance by calibration of a regional groundwater flow model: Desert Hot Springs,California 总被引:1,自引:2,他引:1
The hydraulic conductance of a large fault zone has been estimated by calibrating a regional groundwater flow model. Drops in groundwater elevations of over 80 m have been observed along a 15-km length of the Mission Creek fault, California, USA. The large drops in elevation are attributed to the reduced hydraulic conductivity of the fault materials. A conceptual and numerical model of the two hydrologic subbasins in Desert Hot Springs, separated by the Mission Creek fault, was developed. The model was used to estimate the hydraulic conductance along the fault. The parameter estimation involved calibrating the model with observed groundwater elevations from over 40 locations over a 60-year period. The fault hydraulic conductances were estimated assuming a linear trend in the fault length, yielding variations in the fault hydraulic conductance of about an order of magnitude along the fault length (2?×?10?11–4?×?10?10 1/s). When an average fault thickness of 35 m is assumed, the fault hydraulic conductivity values are estimated to be from three to five orders of magnitude lower than the surrounding materials. A sensitivity analysis indicated that assumptions made in the conceptual model do not significantly affect estimated fault hydraulic conductances. 相似文献
744.
通化二密地区中生代火山成矿作用及找矿方向 总被引:2,自引:2,他引:2
通过对二密地区中生代火山活动规律,岩浆演化序列、火山喷发期次与成矿作用的研究,对控制火山活动的基底断裂构造的调查,以及松顶山石英闪长岩(次火山岩)岩石单位的划分,认为:该地区成矿与中生代侏罗纪火山活动密切相关;成矿时间长、期次多、矿体类型复杂;区内尚存在很好的找矿远景,按照新的找矿方向,在火山活动中心成矿条件有利于段采用有效的找矿手段,有望找到新的矿产基地或隐伏的工业矿体。 相似文献
745.
金厂特大型金矿床的地质特征与成因研究 总被引:18,自引:0,他引:18
金厂特大型金矿床产于吉黑东部兴凯地块太平岭隆起与老黑山断陷的交接部位,矿区外围出露新元古界黄松群变质岩系。本区燕山期岩浆活动可分为5期,分别为燕山早期第一阶段闪长岩(δ52-1)、燕山早期第二阶段文象花岗岩(γo52-2)、燕山早期第三阶段花岗岩(γ52-3)、燕山晚期第一阶段花岗斑岩(γπ53-1)、燕山晚期第二阶段闪长玢岩脉(δμ53-2),形成岩浆穹窿型构造和隐爆角砾岩筒构造,并叠加大规模的热液蚀变活动,金矿化与第4、5期岩浆活动紧密相关。金矿矿体产状有三种类型:岩浆穹窿构造型、隐爆角砾岩型和环状放射状断裂型。矿石类型主要有含金黄铁矿化石英脉、含金石英黄铁矿脉、含金多金属硫化物石英脉、含金黄铁矿化方解石脉等。金矿成矿年龄为119.40 -122.53 Ma。金矿体受统一的构造-岩浆流体蚀变系统控制,成矿物质来源于深部,成矿流体为岩浆水,晚阶段有少量大气水加入。成矿环境为中高温、中等压力,流体盐度为中等偏高,流体性质为弱碱性、弱还原性,属于K -Na - Ca2 -Cl--SO42-型流体。金在成矿流体中以[Au(HS)2]-、[AuCl2]-、[Au(CO3)]-及[Au(HCO3)2]-等络合物形式存在,当温度、压力下降时,溶液由酸性演化为弱酸性再到弱碱性时,络合物离解,金沉淀成矿。 相似文献
746.
747.
Experimental and numerical investigation for energy dissipation of supercritical flow in sudden contractions 下载免费PDF全文
Rasoul Daneshfaraz Ehsan Aminvash Reza Esmaeli Sina Sadeghfam John Abraham 《地下水科学与工程》2020,8(4):396-406
Dealing with kinetic energy is one of the most important problems in hydraulic structures, and this energy can damage downstream structures. This study aims to study energy dissipation of supercritical water flow passing through a sudden contraction. The experiments were conducted on a sudden contraction with 15 cm width. A 30 cm wide flume was installed. The relative contraction ranged from 8.9 to 9.7, where relative contraction refers to the ratio of contraction width to initial flow depth. The Froude value in the investigation varied from 2 to 7. The contraction width of numerical simulation was 5~15 cm, the relative contraction was 8.9~12.42, and the Froude value ranged from 8.9~12.42. In order to simulate turbulence, the k-ε RNG model was harnessed. The experimental and numerical results demonstrate that the energy dissipation increases with the increase of Froude value. Also, with the sudden contraction, the rate of relative depreciation of energy is increased due to the increase in backwater profile and downstream flow depth. The experimentation verifies the numerical results with a correlation coefficient of 0.99 and the root mean square error is 0.02. 相似文献
748.
吉沙水电站低压引水隧洞,位于青藏高原的东南端,地质环境条件复杂。通过勘查,对工程区的地貌特征、地层岩性、地质构造、水文地质、工程地质特征有了基本了解,对引水隧洞区存在的上覆岩体厚度问题,围岩稳定及施工涌水问题.隧洞外水压力问题以及岩体工程地质问题进行了分析与评价,并提出了工程处理建议。 相似文献
749.
750.
Transformations and hydraulic captures of petrochemical contaminants in a karst-fractured aquifer 总被引:2,自引:0,他引:2
Yudao Chen Xueyu Zhu Xueshun Zhu Yaping Jiang Qinglin Xie 《Environmental Geology》2000,39(11):1304-1308
The development of a petrochemical industry may be responsible for petrochemical contamination of karst-fractured aquifers
in an urban water supply system. In the Dawu Well Field, a karst-fractured aquifer in Zibo City, in the east of China, has
been seriously polluted by petrochemicals from the operation of petrochemical plants. More than 60 species of organic contaminants
have been detected in the water supply wells of the Liuhang-Hougao zone, in the west part of Dawu Well Field. Investigations
indicate that contaminants are transported from the petrochemical plants to the karst-fractured aquifer along karst fractures
and the Jinling Fault. In the groundwater, concentrations of pollutants vary with depth. Concentrations are greater with depth
because of the transmissibility of the Jinling fault. The local convective flow field has a significant influence on transportation
of contaminants. Hydraulic barriers can prevent the transportation of contaminants and they can be removed by extraction.
Received: 22 October 1999 · Accepted: 14 February 2000 相似文献