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21.
Hussain Sheikha Anil K. Mehrotra Mehran Pooladi-Darvish 《Journal of Petroleum Science and Engineering》2006,53(3-4):189-202
An inverse solution methodology is developed for the estimation of diffusion coefficient of gases in highly viscous, oil-sands bitumens from isothermal, pressure-decay measurements. The approach involves modeling the rate of change in pressure using the diffusion equation for the liquid phase coupled with a mass balance equation for the gas phase. The inverse solution framework is utilized to arrive at two graphical techniques for estimating the diffusion coefficient. Both techniques involve the determination of the slope of a straight line resulting from plotting the experimental data in accordance with the developed model. An advantage of the proposed techniques is that the diffusion coefficient is estimated directly, i.e. without making it an adjustable parameter. The novelty of the proposed method is in its simplicity as well as its ability to isolate portions of the pressure-decay data affected by experimental fluctuations. The effect of the initial pressure on the predicted diffusion coefficient and pressure-decay profile was also investigated. The diffusion coefficients of CO2, CH4, C2H6 and N2 in Athabasca bitumen at 50–90 °C and about 8 MPa were estimated and compared with literature values. 相似文献
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油,水二相流固耦合渗流的数学模型 总被引:12,自引:1,他引:11
为了正确模拟油藏中流体流动的动态过程,必须考虑由于注水和开采而引起的多相流体的流动、应力状态的变化和储集层变形之间复杂的相互作用。但由于这种问题的控制方程是三维非线性耦合方程,因此,很难模拟这种耦合作用。利用广义的Biot理论建立了一个完全耦合的数学模型,它描述可变形油藏中岩石变形和油水流动的这种相互作用。模型中假设岩石骨架具有弹塑性特性,流体是可压缩的。以岩石骨架位移和油水压力为未知变量所建立的控制方程,包括岩石骨架的平衡方程和流体(油、水)的连续性方程。所建立的流固耦合模型在石油工程,特别是在油藏数值模拟中有广泛的应用。参8(陈志宏摘 相似文献
24.
针对UO_3的N_2还原反应建立了多孔挡板流化床反应器模型。将多孔挡板床的每一级视为具有相似的流动状态,每一级的上、下段称为稀、密相段,分别用鼓泡床和活塞流模型描述。该模型的计算值与¢63mm的多孔挡板床H_2还原UO_3的热态实验值能较好的吻合。还预计了还原温度、操作气速和挡板结构参数对固相转化率的影响,为该类反应器的工业设计、放大和优化提供了依据。 相似文献
25.
圆管状声波换能器瞬态过程的分析 总被引:1,自引:0,他引:1
结合石油测井的实际情况,首次从理论上对常规声波测井仪中采用的圆管状压电陶瓷声波换能器在阶跃电压、冲激电压和正弦间断电压等激励信号的作用下的瞬态过程进行了分析,推导出了在上述几种情况下圆管状压电陶瓷换能器的声源函数和谱函数,并叙述了推导结果在声皮测井中的应用。 相似文献
26.
The pressure variations during polymer flooding of oil reservoirs for oil recovery projects can be used to analyze the flow in the reservoir which is especially useful for the partially perforated reservoirs. This paper presents a relationship between the viscosity and the shear rate which is similar to forms developed for radial flow (Odeh, A. S., Yang, H. T. ([1979]). SPEJ. AIME (Jun.) 155). The power-law viscosity model is used to give the variation of the fluid viscosity with the spherical radius for a mathematical model of unsteady spherical flow for non-Newtonian fluids with wellbore storage and skin. An analytical solution for the wellbore pressure responses derived in Laplace space is used to analyze the behavior characteristics at early and later times to interpret the well-test parameters. The pressure variations are similar to those for a Newtonian fluid at the early times, but at later times, the variation of the viscosity with the power-law exponent is important, so the pressure response differs from that for a Newtonian fluid. The solution has significance for interpreting well test parameters for non-Newtonian spherical flow. 相似文献
27.
Elias G. Abu‐Saba William M. McGinley Raymond C. Montgomery 《Canadian Metallurgical Quarterly》1991,4(4):347-354
As the manned exploration of space continues, many complex structural components are being developed to construct the orbital platforms that will be used to house communication hardware, personnel, and manufacturing complexes. These components are extremely flexible and complex in their behavior. There is a need for a simple method for determining the dynamic characteristics of these space structures with a minimum of effort. A mathematical model of one of these structural elements, an articulating truss beam, has been developed to predict its dynamic response. Assumptions of the force interaction between the beam elements and the joints have been made for using this model. Algorithms are provided to determine the flexibility matrix of the truss beam for use in the equation of motion. The natural frequencies obtained from using this method are compared with those obtained by the finite element method. An experimental procedure is planned to validate the results from the theoretical method. 相似文献
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This paper studies a system of partial differential equations modelling the behaviour of a reverse flow reactor. For the parameters appropriate for the oxidation of ammonia on a Pt/Al2O3 catalyst in a typical laboratory set-up, the reactor may be split into regions where approximate formulas that determine its behaviour are deduced. Numerical calculations are presented and can be used to compare with the analytical formulas. The physical insight gained from the asymptotic analysis suggests a new switching strategy which is the subject of numerical experiments. The switching strategy is found to be efficient at minimising the ammonia exiting the reactor after reversal. 相似文献
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