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41.
《Journal of power sources》2006,159(2):1300-1304
A composite photocatalyst, Pd–TiO2−xNx–WO3, was synthesized by the template method and characterized by energy dispersive X-ray microanalysis (EDX), X-ray diffraction (XRD), UV–vis spectrometer, and scanning electron microscope (SEM). The results of EDX analysis reveals that the molecular formula of the composite photocatalyst can be expressed as Pd–TiO1.72N0.28–WO3. The UV–vis absorption spectrum indicates that the absorption edge of the catalyst red-shifts to around 600 nm. Under the irradiation with ultraviolet and visible light, the catalyst showed good performance for photocatalytic hydrogen production with a Na2S/Na2SO3 system as the sacrificial agent. 相似文献
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An algebraic concentration moment (ACM)-PDF turbulent combustion model is proposed and formulated in this paper. The presumed PDF approach is adopted for the closure of the time-averaged temperature relevant quantity. It is integrated with the algebraic expression for the second-order-moment of concentration fluctuations. The obtained ACM-PDF model is employed in the simulation of swirling turbulent diffusion combustion in the TECFLAM combustor. The calculated gas axial, radial and tangential velocities, turbulent kinetic energy, species mass fractions, temperature, and fluctuating temperature are compared with the measured test data. Agreement between the calculation and the measurement is achieved. 相似文献
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《International Journal of Hydrogen Energy》2019,44(7):3953-3965
Tempering temperatures ranging between 500 and 720 °C were applied in order to analyse the relationship between steel microstructure and the deleterious effect of hydrogen on the fracture toughness of different CrMo and CrMoV steels. The influence of hydrogen on the fracture behaviour of the steel was investigated by means of fracture toughness tests using CT specimens thermally pre-charged with hydrogen gas.First, the specimens were pre-charged with gaseous hydrogen in a pressurized reactor at 19.5 MPa and 450 °C for 21h and elasto-plastic fracture toughness tests were performed under different displacement rates. The amount of hydrogen accumulated in the steel was subsequently determined in order to justify the fracture toughness results obtained with the different steel grades. Finally, scanning electron microscopy was employed to study both the resulting steel microstructures and the fracture micromechanisms that took place during the fracture tests.According to the results, hydrogen solubility was seen to decrease with increasing tempering temperature, due to the fact that hydrogen microstructural trapping is lower in relaxed martensitic microstructures, the strong effect of the presence of vanadium carbides also being noted in this same respect. Hydrogen embrittlement was also found to be much greater in the grades tempered at the lowest temperatures (with higher yield strength). Moreover, a change in the fracture micromechanism, from ductile (microvoid coalescence, MVC), in the absence of hydrogen, to intermediate (plasticity-related hydrogen induced cracking, PRHIC) and brittle (intergranular fracture, IG), was appreciated with the increase in the embrittlement indexes. 相似文献
47.
《Applied Thermal Engineering》2003,23(9):1067-1083
This paper introduces some typical cases of industrial applications, which include the equipment for the waste heat recovery and the industrial process equipment. Carbon steel–water heat pipe technology, applied to air preheater and waste heat boiler, has been successfully used in many fields, such as waste heat recovery, energy conservation and environmental protection. Liquid metal high-temperature heat pipe technology has been extensively employed in the process equipment, for example, high-temperature hot air generators and heat extractors. Heat pipe technology also finds its use in chemical reactors including ammonia converters. The success of applications is founded on the basis of fundamental research of heat pipe technology, which includes the theoretical and experimental researches on the vapor–liquid two-phase flow and heat transfer inside the heat pipe, the heat transfer limits of heat pipes, the heat transfer enhancement with heat pipes, and researches on the material compatibility and life tests of heat pipes. Hi-efficient heat pipe heat and mass transfer equipment is going to play a more and more important role in the various industrial fields. 相似文献
48.
The effects of magnetic fields were generally formulated on the thermodynamic properties of chemical reactions. The magnetic field-induced change in the heat of reaction was calculated for the metal–hydrogen system, especially for LaCo5-H2, on the basis of the general formulation. Independently of this, the heat of reaction under the influence of magnetic fields was estimated from the temperature dependence of the equilibrium hydrogen pressure. The agreement between both the results indicated that magnetic fields influence the heat of reaction in metal–hydrogen systems. 相似文献
49.
针对循环流化床锅炉(CFB)底渣利用率偏低的问题,提出一种新的底渣处理应用方案——对底渣进行急冷处理后,将其作为脱硫剂或水泥混合材进行综合利用。本文通过搭建CFB锅炉底渣急冷实验系统,制备了不同渣温下的急冷底渣样品;然后选取亿利底渣和42.5标号的水泥作为研究对象,探讨了急冷底渣作混合材对水泥性能的影响。实验结果表明:急冷会破坏底渣颗粒形状,导致外壳成分发生变化。急冷处理不仅造成CaSO4峰值显著降低,而且使得Ca(OH)2的特征峰变强。在相同的CFB底渣掺比下,与原始底渣相比,急冷底渣作为水泥混合材时,虽然无助于提高抗折抗压强度,但能缩短凝结时间,减少安定性值。同时,还能减少水泥标准稠度需水量,提升水泥的密实程度,对水泥的力学性能和抗侵蚀性有着一定的积极作用。 相似文献
50.
The accurate modelling and investigating effects of various parameters of the reciprocating compressors are important subjects. In this work, based on first law of thermodynamics, conversation of mass and real and ideal gas assumptions, a theoretical analysis has been constructed to simulate natural gas reciprocating compressors. For computing the thermodynamic properties of natural gas based on real gas model, the AGA8 equation of state has been used. Numerical results validated with previous measured values and showed a good agreement. The effects of important parameters such as: angular speed, clearance and pressure ratio have been studied on the performance of the compressors. The results reveal the in-control volume temperature for ideal gas is more than real gas model but the mass flow rate and work for real gas is higher than ideal gas model. On the other hand, the indicated work that required for compression is greater for ideal gas model. 相似文献