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831.
Horino  Hideyuki  Liu  Suwen  Sano  Manami  Wako  Sugio  Hiratsuka  Atsuko  Ohno  Yuichi  Kobal  Ivan  Matsushima  Tatsuo 《Topics in Catalysis》2002,18(1-2):21-26
Two-directional N2 desorption was found in N2O decomposition on Pd(110) at 100–160 K. It collimated ±43° off the surface normal in the (001) plane. A hot-atom-assisted model is proposed for N2 desorption. Inclined O2 desorption was simulated by hot atoms emitted from aligned oxygen molecules on stepped Pt(112) at 308 nm irradiation.  相似文献   
832.
The relationship between the fluorescence behavior and crystallinity of poly(1,4-butylene terephthalate) (PBT) films, prepared by a spin-casting method, was investigated. Throughout the fluorescence measurements of PBT thin films having different crystallinities, the main-chain phenylene fluorescence near 320 nm and that near 365 nm were assigned to monomer fluorescence mainly from crystalline regions and excimer fluorescence from amorphous regions, respectively. It was found that the ratio of the fluorescence intensity at 320 nm to that at 365 nm can be an effective indicator of PBT crystallinity. The present work should provide a quick and nondestructive method for determining the crystallinity of PBT factory products.  相似文献   
833.
834.
Data abstraction and inheritance, some of the most important features in constructing a large, clean software system, in a logic programming language Prolog/KR, an expansion of Prolog, are described. First two kinds of processes are added; one is called NPO, which is mainly used to implement a generator, the other is called CPO, which is mainly used to implement an abstract data object. Then synchronization features are added to implement abstract data types that can be used concurrently. Using this feature it is possible to employ pipes for communications among processes. Finally, inheritance mechanism is added to define hierarchies among objects.  相似文献   
835.
This paper presents a new kind of climbing robots called EJBot, which has not been restricted to climb certain surface materials or terrains. EJBot is inspired by propeller-based aviation systems, however, its adhesion principle is opposite to flight concept. Thanks to the hybrid actuation system embedded in this robot which gives a good and stable adhesion. This hybrid system consists of propeller thrust forces and wheel torques actuated simultaneously to generate the proper adhesion force. It is similar to a car climbing a ramp, it needs both weight of the car and the wheels' torques. Without these torques, the car will roll down. Consequently, the thrust forces of the propellers increase the traction force capacity, then the wheels' role arises to generate the convenient torques for stopping the robot or navigating it on the structures. The feasibility of this adhesion concept is verified by the first and second modules of EJBot as presented in the simulation and practical results.  相似文献   
836.
BACKGROUND: Human embryology textbooks indicate that the trunks of the pulmonary vein and artery originate from the left atrium and aortic sac, respectively, based on histological analyses of limited human specimens. However, our studies show that the pulmonary venous trunk in the mouse as in other nonhuman vertebrates originates from a vascular "sac" at the venous pole, the sinus venosus. METHODS: Mouse embryos of 9-11 days gestation were obtained and staged according to Theiler's criteria and fixed in Carnoy's solution. Samples were embedded in paraffin and serial sections were prepared. RESULTS: Histological analysis showed that at day 9.5 the pulmonary venous rudiment was initially observed along the left margin in the extracardiac mesenchyme that separated the venous pole of the heart from the lung buds. The endothelium of the pulmonary vein was continuous, with a vascular sac we identified as sinus venosus based on its location immediately posterior to the left sinoatrial fold. The sinus venosus became incorporated into the left atrium (days 10-10.5) to form part of the posterior atrial wall. Similarly, the pulmonary vein and associated extracardiac mesenchyme were "drawn" into the atrium. This extracardiac mesenchyme of the venous pole, also called "spina vestibuli" and containing the pulmonary vein at its left margin, formed a wedge-shaped invagination within the atrium that contributed nonmuscular tissue to the primary atrial septum. CONCLUSIONS: We propose that the orifice of the pulmonary vein establishes a link with the left side of the atrium as a consequence of a venous sac, the sinus venosus, and its associated mesenchyme (in which the root of the pulmonary vein is embedded) being incorporated into the atrium.  相似文献   
837.
Abstract— The demand for projectors with high brightness and wide color gamut has been increasing; however, UHP lamp projectors cannot deliver those two qualities efficiently and simultaneously because of its color‐separation system. The newly developed projection system — “Color‐Tuning Projection System” — realizes the adaptive combination of high brightness and wide color gamut with one projector. This projector features a fourth liquid‐crystal panel — “Color Tuner” — with a 3LCD optical engine, which controls yellow light separately from the RGB light of a UHP lamp. This color‐tuner‐based optical engine — “Color‐Tuning Optical Engine” — and a new color‐conversion signal‐processing algorithm — “Adaptive Color Conversion Algorithm” — controls the yellow‐light volume and corrects color‐shifted pixels according to the brightness and chromaticity analysis of the input image, key technologies of the Color‐Tuning Projection System. This additional panel system enables the projector to ach ieve up to 115% higher brightness and 120% wider color gamut according to the input image. This paper presents an innovative design concept, a novel technology regarding brightness and a color‐gamut conversion projection system, and the characteristics of the prototype.  相似文献   
838.
强磁场对铁基合金相变温度和显微组织的影响   总被引:2,自引:0,他引:2  
The effect of a high magnetic field up to 30 T on phase transformation temperature and microstructure of Fe-based alloys has been reviewed. A high magnetic field accelerates ferrite transformation, changes the morphology of the transformed microstructures and increases the As and A1 temperature. In a magnetic field of 30 T, the A1 temperature increases by about 37.1℃ for Fe-0.8C, the A3 temperature for pure Fe increases by about 33.1 ℃. The measured transformation temperature data are not consistent with calculation results using Weiss molecular field theory. Ferrite grains are elongated and aligned along the direction of magnetic field in Fe-0.4C and Fe-0.6C alloys by ferrite transformation, but elongated and aligned structure was not found in pure Fe, Fe-0.05C alloy and Fe-1.5Mn0.11C-0.1V alloy.  相似文献   
839.
The heat treatment of base-metal Ni electrode multilayer capacitors (MLCs) in air was investigated with a view to reducing manufacturing costs. This treatment was found to recover the insulation resistance in the same way as heat treatment under low oxygen partial pressure. At temperatures above 800°C, heat treatment in air was associated with cracking as a result of volumetric expansion of Ni through oxidation. TG-DTA analysis revealed that the oxidation behavior of Ni electrodes in MLCs differs from that of Ni plates or Ni fine powder. The capacitance of 1.2 F MLCs in EIA 1206 size was successfully manufactured by the novel process.  相似文献   
840.
The limiting viscosity number in polystyrene-cyclopentane system has been determined over the temperature range of θu to θl in which θu and θl are the θ or Flory temperature for the upper and lower critical solution temperatures. The temperature coefficient of unperturbed mean square end-to-end distance observed for the polystyrene (Mw=20×104, MwMn<1·06 and Mw=67×104, MwMn<1·10) in cyclopentane is negligibly small. The observed temperature dependence of the polymer chain dimension over the temperature range of θu=19·6° to θl=154·2°C shows a parabolic curve with a maximum in the neighbourhood of 90°C and is qualitatively interpreted by the free volume theory of polymer solution, which gives a new χ1-temperature function.  相似文献   
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