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841.
842.
843.
该文基于有效应力原理建立了描述黏性浆液在小孔隙多孔介质中扩散的流固耦合模型.通过对小孔隙多孔介质注浆过程中的浆液渗流场分布与固体骨架的应力应变特性的流固耦合分析,得到了各动态参数如孔隙率、应变率等的相互关系并在施工现场进行了试验.经过与施工现场试验数据对比,得到的数值分析结果与试验结果基本一致,验证了该流固耦合模型运用于注浆工程的可行性与实用性,可作为小孔隙多孔介质地层防渗注浆设计和注浆效果的初步评判. 相似文献
844.
混凝土防渗墙是保证大坝基础稳定的一种主要防渗措施,在水电工程中的应用极为广泛。色尔古水电站在混凝土重力坝内预留导向槽"分层分仓"施工防渗墙,有效地避免了左岸接头坝的继续开挖,节约了施工工期,规避了施工风险,有效解决了左岸接头坝的绕坝渗漏,确保了大坝安全运行,在施工中取得了较好的成效。 相似文献
845.
846.
LI Yok-sheung 《水动力学研究与进展(B辑)》2011,23(1):95-104
A severe typhoon Utor,occurring between July 3 and 8,2001,brought heavy rainfall,strong wind and storm surge.Utor was responsible for tremendous destruction and economic losses in Philippines,Taiwan and Guangdong.An air-sea model system (MM5 and Princeton Ocean Model(POM))was built to simulate meteorological dynamics and ocean circulation in the South China Sea(SCS).In the POM the output of MM5 was used as the input data.With an increased number of vertical levels,a high-resolution planetary boundary layer scheme and updated landuse/vegetation data,the accuracy of computing wind,temperature and other meteorological fields are improved in near surface and upper levels in MM5 simulations.The simulated trajectory and wind speed of Utor are close to the observed results.The simulated distribution of rainfall is accorded well with measured data in the Pearl River Delta(PRD)area.At different meteorological stations in Hong Kong,the wind,temperature and sea surface pressure are well simulated.The simulated ocean surface current and surface temperature fields have an obvious rightward-biased response to the typhoon Utor,and the maximum velocity and the lowest temperature region appear in the 30 km of the right side of the typhoon track.The typhoon Utor could make the water 50m under the surface ocean unwell to surface and the ocean surface temperature decrease by about 2°C. 相似文献
847.
XIAO Yang TANG Hong-wu State Key Laboratory of Hydrology-Water Resources Hydraulic Engineering Nanjing China College of Water Conservancy Hydropower Engineering Hohai University China LIANG Dong-fang 《水动力学研究与进展(B辑)》2011,(6):806-813
The hydrodynamics of a single jet and four tandem jets in a cross flow are simulated by using the Computational Fluid Dynamics (CFD) software Fluent. The realizable model is used to close the Reynolds-Averaged equations. The flow characteristics of the jets, including the jet trajectory, the velocity field and the turbulent kinetic energy are obtained with various jet-to-cross flow velocity ratios in the range of 2.38-17.88. It is shown that a single jet penetrates slightly deeper than the first jet in a jet group at the same , although the difference decreases with the decrease of . It is also found that the way in which the velo-city decays along the centerline of the jet is similar for both a single jet and the first jet in a group, and the speed of the decay increases with the decrease of . The downstream jets in a group are found to behave differently due to the sheltering effect of the first jet in the group. Compared with the first jet, the downstream jets penetrate deeper into the cross flow, and the velocity decays more slowly. The circulation zone between the two upstream jets in the front is stronger than those formed between the downstream jets. The Turbulent Kinetic Energy (TKE) sees a distinct double-peak across the cross-sections close to each nozzle, with low values in the jet core and high values in the shear layers. The double-peak gradually vanishes, as the shear layers of the jet merge further away from the nozzle, where the TKE assumes peaks at the jet centerline. 相似文献
848.
The time-varying viscosity of common grout and the controllable grout are measured with a rotation viscometer in experiments.The time-varying viscosity of grout is analyzed according to the characteristics in the process of anti-seepage treatment for gravel foundation.The principle of effective stress for porous medium is applied to analyzes the fluid-structure coupling in grouting.In the consideration of coupling physical variables,dynamic models of porosity,permeability and viscosity are constructed.The diffusion radius can thus be defined by the foundational porosity.The distribution of holes in field experiments is designed according to the diffusion radius of grout.Then,the permeability test is designed to verify the grout effect.The calculated diffusion radius coincides with experimental results,and the permeability meets the requirements of the project,which is valuable for the anti-seepage treatment in gravel foundation. 相似文献
849.
为支持崇明生态岛建设,在现状崇明岛水利控制工程的基础上,研究选取不同等级暴雨雨型和不同特征潮型的组合对崇明岛除涝排水能力进行计算,对预降能力、暴雨期间最高水位以及暴雨后排水时间等参数进行分析,并根据研究结果提出不同等级暴雨预报情况下调整水闸引排模式、预降水位的建议。 相似文献
850.
针对传统的地震属性图像可视化过程中存在的缺点,论文提出一种基于直方图技术的地震属性图像配色阈值选取算法,该算法利用直方图统计的结果,首先进行阈值预选,然后在区间内进行阈值调整,最后根据所确定的阈值对地震属性图像进行重新配色,很好地解决了传统地震属性图像视觉上的杂乱以及区域性差的缺点。经过对大庆油田多个区块地震属性图像的分析,该算法可有效解决地震图像可视化中的不足,提高了地震解释工作的效率。 相似文献