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71.
Twitter has become an important data source for detecting events, especially tracking detailed information for events of a specific domain. Previous studies on targeted-domain Twitter information extraction have used supervised learning techniques to identify domain-related tweets, however, the need for extensive manual labeling makes these supervised systems extremely expensive to build and maintain. What’s more, most of these existing work fail to consider spatiotemporal factors, which are essential attributes of target-domain events. In this paper, we propose a semi-supervised method for Automatical Targeted-domain Spatiotemporal Event Detection (ATSED) in Twitter. Given a targeted domain, ATSED first learns tweet labels from historical data, and then detects on-going events from real-time Twitter data streams. Specifically, an efficient label generation algorithm is proposed to automatically recognize tweet labels from domain-related news articles, a customized classifier is created for Twitter data analysis by utilizing tweets’ distinguishing features, and a novel multinomial spatial-scan model is provided to identify geographical locations for detected events. Experiments on 305 million tweets demonstrated the effectiveness of this new approach.  相似文献   
72.
Wireless Personal Communications - Efficiency can be achieved in CEAACK MANETs by implementing clustering technique into the network. Using this strategy the cluster head can monitor the members...  相似文献   
73.
The effect of Gate-Source/Drain underlap (L un) on soft error performance in 30 nm common double gate-FinFET (simultaneously driven gates) and independent double gate-FinFET (independently driven gates) have been examined through extensive mixed mode-device and circuit simulations using Sentaurus TCAD. Four different 6T-SRAM topologies, one simultaneously driven double gate-FinFET and three independently driven double gate-FinFETs-based topologies namely Flex-V TH, Flex-PG, and PG-SN are chosen to study the geometrical parameter L un and also to calculate their soft error performance. When L un increases, current decreases due to increase in parasitic series resistance. The simulation results reveal that L un increase in independently driven double gate-FinFETs in place of access devices in 6T-SRAM does not degrade the soft error performance significantly whereas the L un increase inside the cell, in the inverters, degrade the performance significantly.  相似文献   
74.
让周遭的系统能够自动感测环境变化并做出反应,势必将对于人类的生活造成重大改变。无线传感器网络是多个分布式传感器实作(节点)组成的系统,能够共同透过相互无线通信的方式响应实体变化。本文将重点介绍节点的最新进展,并推广对于系统层级设计方法的需求。  相似文献   
75.
A permeability measurement method based on perturbed pressure decay between a source and a sink communicating through a porous medium is formulated. Nonideality of gas as well as corrections due to adsorption are considered. The method allows us to infer permeability at a given rock and fluid state. The accuracy of the method may be evaluated through comparison with theoretical decay characteristics and its modal amplitudes. A quantitative evaluation of the experimental inference is therefore possible. Based on the pressure decay theory, an apparatus built in our laboratory for measuring permeability is presented. As a secondary output, data analysis also provides porosity. The lowest permeability that the present apparatus is capable of characterizing is about 0.3 nm2, and with additional improvements, capability down to 0.05 nm2 is anticipated. Where a steady‐state permeameter is pragmatic, excellent agreement between the two measurements is showed, validating the method. Measurements in synthetic samples also show that the method is accurate. Porosity data from a standard helium pycnometer confirm the porosity obtained from the decay method. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1278–1293, 2016  相似文献   
76.
Ramkumar  K.  Ramakrishnan  V. N. 《SILICON》2022,14(16):10603-10612
Silicon - The performance analysis of Ge-Si-VTFETs for analog/RF applications has been studied in this article under various gate dielectric materials. In the proposed device, Ge/Si materials were...  相似文献   
77.
Journal of Mechanical Science and Technology - Achieving stability of unmanned, heavy tracked vehicles is challenging, especially under conditions of teleoperation because the remote operator...  相似文献   
78.
Self‐condensation of AB2 type monomers (containing one A‐type and two B‐type functional groups) generates hyperbranched (HB) polymers that carry numerous B ‐type end‐groups at their molecular periphery; thus, development of synthetic methods that directly provide quantitatively transformable peripheral B groups would be of immense value as this would provide easy access to multiply functionalized HB systems. A readily accessible AB2 monomer, namely diallyl, 5‐(4‐hydroxybutoxy)isophthalate was synthesized, which on polymerization under standard melt‐transesterfication conditions yielded a peripherally clickable HB polyester in a single step; the allyl groups were quantitatively reacted with a variety of thiols using the facile photoinitiated “thiol‐ene” reaction to generate a wide range of derivatives, with varying solubility and thermal properties. Furthermore, it is shown that the peripheral allyl double bonds can also be readily epoxidized using meta‐chloroperoxybenzoic acid to yield interesting HB systems, which could potentially serve as a multifunctional cross‐linking agent in epoxy formulations. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40248.  相似文献   
79.
Polyamine oxidation plays a major role in neurodegenerative diseases. Previous studies from our laboratory demonstrated that spermine oxidase (SMOX, a member of the polyamine oxidase family) inhibition using MDL 72527 reduced neurodegeneration in models of retinal excitotoxicity and diabetic retinopathy. However, the mechanisms behind the neuroprotection offered by SMOX inhibition are not completely studied. Utilizing the experimental model of retinal excitotoxicity, the present study determined the impact of SMOX blockade in retinal neuroinflammation. Our results demonstrated upregulation in the number of cells positive for Iba-1 (ionized calcium-binding adaptor molecule 1), CD (Cluster Differentiation) 68, and CD16/32 in excitotoxicity-induced retinas, while MDL 72527 treatment reduced these changes, along with increases in the number of cells positive for Arginase1 and CD206. When retinal excitotoxicity upregulated several pro-inflammatory genes, MDL 72527 treatment reduced many of them and increased anti-inflammatory genes. Furthermore, SMOX inhibition upregulated antioxidant signaling (indicated by elevated Nrf2 and HO-1 levels) and reduced protein-conjugated acrolein in excitotoxic retinas. In vitro studies using C8-B4 cells showed changes in cellular morphology and increased reactive oxygen species formation in response to acrolein (a product of SMOX activity) treatment. Overall, our findings indicate that the inhibition SMOX pathway reduced neuroinflammation and upregulated antioxidant signaling in the retina.  相似文献   
80.
Volumetric heating provided by microwave curing results in faster property development as compared to conventional heat curing that relies on heat conduction from the skin to the core. This paper discusses the compressive strength and microstructure development of microwave cured NaOH activated fly ash mortars, and relates them to the microwave energy absorption by the material which is a function of its dielectric properties. Microwave curing parameters are chosen so as to eliminate the effects of thermal runaway. Strengths that are comparable to or greater than those of mortars heat cured for 48 h at 75 °C are obtained in less than 120 min of microwave curing. The rate of energy absorption by the mortars is found to be relatively constant for a considerable fraction of the microwave curing duration, attributable to the compensation for the drop in dielectric loss factor as a result of moisture loss by the increase in internal electric field. Compressive strength is shown to be related to the microwave energy absorbed by the specimens, especially during the time when free water is present in the system.  相似文献   
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