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51.
水力旋流器内固相颗粒时均流场及脉动特性的研究 总被引:1,自引:0,他引:1
利用一种新型的激光多普勒测速仪———粒子动态分析仪(PDA),对水力旋流器中固相颗粒的时均流速、绝对湍流度、相对湍流度等流动参数进行了实测研究,给出了更全面的关于水力旋流器内固相颗粒流速分布的信息,并探讨了湍流脉动对水力旋流器分离过程的影响。 相似文献
52.
西部地区地下构造复杂,地层埋深较深,地震资料采集中,炮检距较大,地下介质的各向异性问题表现得较为明显。此时应用常规方法进行速度分析精度将变低,进而影响地震资料的成像质量。针对以上问题本文重点对VTI介质速度分析原理、各向异性参数求取方法进行了研究,并总结了一套各向异性参数求取的方法。通过模型试算和胜利西部资料的实际应用,表明各向异性速度分析技术是提高速度分析精度,改善成像效果的有效方法。 相似文献
53.
针对丁苯橡胶装置100 m3凝聚釜在运行中存在的搅拌效果不理想、釜内液面容易积胶、搅拌轴摆动大、中间轴承易磨损、调节拉杆易断裂等不足之处,提出了搅拌器改造方案。搅拌器采用CBY桨叶,取消中间轴承和调节拉杆,增大搅拌轴直径。这次改造满足了生产需要,改善了搅拌器搅拌效果,解决了搅拌器故障,延长了凝聚釜使用周期。 相似文献
54.
Sławomir Jodzis 《臭氧:科学与工程》2012,34(5):378-386
Results of studies on ozone synthesis under discharges proceeding in a metal mesh-ceramic dielectric system have been presented. The experiments were carried out in the reactor with unique reaction space geometry, in which the reacting gas flew with consequently increasing linear velocity. The high voltage electrode was made of a metal mesh, which caused intensification of the gas mixing in the reaction space. Using a simple reactor with one-side cooling of the reaction space, high ozone maximum concentrations (100 g/Nm3) and energy efficiencies (180–200 g/kWh) were obtained at 25 °C. 相似文献
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Non-Newtonian fluid flow characteristics in inflatable and collapsible elastic tubes are relevant to bio-fluid mechanics and other applications. The radial velocity profiles in an elastic tube during steady laminar flow of a shear thinning aqueous solution of 1.5% carboxy methyl cellulose (CMC) were investigated using ultrasound Doppler velocimetry. The shear rate–dependent viscosities obtained using a rheometer were well represented by the Carreau model. Measured storage and loss moduli indicated the CMC solution to be inelastic up to 2% concentration. The velocity profiles were predicted by integrating the theoretical equation derived by equating the shear stress along the tube radius involving pressure drop to that of the Carreau model using its parameters. The agreement between predicted and measured velocity profiles was good. The predicted pressure drop is about the same as the experimental value at lower flow rates. In contrast, the measured pressure drop is lower than that predicted at higher flow rates due to inflation of the tube. Good agreement between estimation (Hagen-Poiseuille's law) and measurement (tube shape image analysis) for the detection of elastic tube expansion while increasing flow rates is found. 相似文献
57.
REUEL SHINNAR 《Chemical Engineering Communications》2013,200(1-6):73-99
The relation between modelling and design of control systems for chemical reactors is discussed, using several practical examples. Criteria for controlability and satisfactory response are proposed. The dependence of the controller structure on the properties of the reactor model is investigated, and it is shown that the most important decisions in controller design occur during process design. The information required for controller design is different from the information required for scaleup, and depends on the design approach. Examples chosen are control of a fluid catalytic cracker, a hydrocracker, and a crystallizer. Control and reactor modelling are not only often separate activities by themselves, but they are done in separate groups and current practice is to call the control engineering in after the design is finished or the plant either operates or is scheduled to start operation. If we want to make significant advances, we have to realize that some of the most important decisions that affect plant control are made during the pilot plant operation and steady stale process design, and we should make control an essential part of process and reactor design. 相似文献
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采用激光多普勒测速仪(简称LDV)对U型弯管流场进行了测量,得到切向速度与轴向速度的分布。进而证明了流体在弯管内流动受弯管壁的限制,被强制沿弯管作适体的圆周运动而产生惯性离心力,表现出压力不均匀分布流体的速度。轴向速度的存在也证明了在U型弯管湍流流场中,存在着较为强烈的二次流。 相似文献
60.
A technique of Positron Emission Particle Tracking (PEPT) was used to obtain information on the flow behavior of coarse particles suspended in pseudoplastic liquids agitated by axial‐hydrofoil Lightnin impellers A320 and A410. PEPT enables the position of a 600 μm radioactive particle tracer inserted inside one of the suspended particles to be detected many times per second and its full trajectory followed inside the vessel. Particle trajectory analysis yielded information on particle circulation, velocity distribution, and spatial occupancy. The minimum speed for complete particle suspension, Njs, was also determined. The well‐known Zwietering correlation failed to predict the measurements by a substantial margin, suggesting that it is inadequate for viscous non‐Newtonian liquids. 相似文献