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161.
Sivaraman R Rajagopalan Sundararaman Amirtharajan Rengarajan 《Multimedia Tools and Applications》2020,79(19-20):13841-13868
Multimedia Tools and Applications - True Random Number Generator (TRNG) has become a central element of today’s secure communication. TRNGs developed through FPGA implementation have a... 相似文献
162.
We propose a model for the interframe correspondences existing between pixels of an image sequence. These correspondences form the elements of a field called the motion field. In our model, spatial neighborhoods of motion elements are related based on a generalization of autoregressive (AR) modeling of the time-series. We also propose a joint spatio-temporal model by including spatial neighborhoods of pixel intensities in the motion model. A fundamental difference of our approach with most previous approaches to modeling motion is in basing our model on concepts from statistical signal processing. The developments in this paper give rise to the promise of extending well-understood tools of signal processing (e.g., filtering) to the analysis and processing of motion fields. Simulation results presented show the performance of our models in interframe prediction; specifically, on average the motion model performs 29% better in terms of the mean squared error energy over a commonly used pel-recursive approach. The spatio-temporal model improves the prediction efficiencies by 8% over the motion model. Our model can also be used to obtain estimates of the optical flow field as the simulations demonstrate. 相似文献
163.
Rajagopalan C. Lesieutre B.C. Sauer P.W. Pai M.A. 《Power Systems, IEEE Transactions on》1992,7(3):990-1000
The authors investigate the dynamic aspects of operation on a typical voltage/power curve. They discuss multiple stable equilibrium points in the context of small signal stability. A single machine example supplying different types of voltage-dependent loads is examined. A multimachine power system is also studied. Examples include a discussion on multiple stable operating points and the effects of different load characteristics 相似文献
164.
The deposition of polydisperse particles under the influence of gravity is examined using computer simulation. A parameter,
σ, that represents the standard deviation of particle size is used for studying the effect of the variation in polydispersity
on the resulting microstructures. Structural correlations are examined through contact networks, radial and angular distribution
functions, and diffraction patterns. The results show that the onset of ordering appears near σ = 0.05 as σ is decreased.
The long-range ordering of the structures is not influenced by the introduction of a small amount of polydispersity, which
may increase the uniformity of local density distribution in the angular direction. Polydisperse systems with small deviations
in size display stronger positional order in some directions and this in turn contributes to the uniformity of overall packing
structures. 相似文献
165.
The transmission of two frequency-division-multiplexed full motion network quality video channels and one digital ISDN-H1 channel over a repeaterless single-mode fibre in excess of eleven kilometres using a LED operating at 1300 nm wavelength is demonstrated. Transmitted video quality, and bit error rate performance of the digital channel are reported. Experimental system components and procedures are described in detail 相似文献
166.
The usefulness of the static condensation technique in the finite element analysis of stiffened submersible. cylindrical hulls is examined in this paper. The finite element formulation used herein is essentially the same as outlined by the authors in an earlier paper wherein the stiffener is modeled rigorously using axisymmetric thin annular plate elements for the web and axisymmetric thin shell elements for the flange. The static condensation technique has been applied in this paper to reduce these stiffener finite elements so that their effect can be transferred to the shell node at the point of attachment of the stiffener with the shell. The advantage of such condensation of the stiffener elements is the smaller number of equations to be solved without the rigor of the stiffener modeling being lost in any way. The manner of incorporating the condensation in the computer program has been described. Examples of several stiffened submersible cylindrical hulls have been considered as an illustration of the use of the program. 相似文献
167.
The essential requirements for the industrial preparation of potassium gold cyanide (pgc) are: (a) high rate of dissolution and (b) smooth and uniform dissolution. Employing galvanostatic and potentiostatic polarisation
data and observations on the surface topography of anodes dissolved by both the techniques, it is shown that potentiostatic
dissolution of gold in potassium cyanide at +0·345 V satisfies the above requirements. 相似文献
168.
New single asymmetric error-correcting codes 总被引:1,自引:0,他引:1
Al-Bassam S. Venkatesan R. Al-Muhammadi S. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1997,43(5):1619-1623
New single asymmetric error-correcting codes are proposed. These codes are better than existing codes when the code length n is greater than 10, except for n=12 and n=15. In many cases one can construct a code C containing at least [2n/n] codewords. It is known that a code with |C|⩾[2n/(n+1)] can be easily obtained. It should be noted that the proposed codes for n=12 and n=15 are also the best known codes that can be explicitly constructed, since the best of the existing codes for these values of n are based on combinatorial arguments. Useful partitions of binary vectors are also presented 相似文献
169.
The present investigation was designed to characterize the biochemical and connective tissue components and to correlate the significance of morphological and biochemical perturbations in cyclophosphamide (CP)-induced lung fibrosis in rats. Lung fibrosis was induced in male Wistar rats by intraperitoneal injection of 20 mg/100 g body weight of CP, and their pneumotoxic derangements were characterized during an early destructive phase followed by a proliferative and synthetic phase. Serum angiotensin-converting enzyme (ACE) activity was higher in CP-treated rats at days 2, 3, 5, 7, and 11, but there was a significant decrease in lung ACE activity during the same time period. Elevated levels of beta-glucuronidase activity were observed in the lung lavage fluid of CP-administered rats days 2, 3, 5, and 7. Lung myeloperoxidase activity was higher in CP rats. Of significance was the presence of collagenase and collagenolytic cathepsin in the lavage fluid of CP rats, when compared with the barely detectable levels in controls. A similar increase in these enzyme activities was also noticed in the lung tissue of CP rats during the same experimental period. Lavage fluid hydroxyproline content was higher in CP rats when compared with controls. Similarly, lung protein and DNA levels were elevated significantly after treatment with CP. The pulmonary histamine and serotonin contents were significantly higher in CP rats. The incorporation of [3H]thymidine into lung total DNA, [3H]proline into lung hydroxyproline, and [35S]sulphate into lung glycosaminoglycan, measured as indicators of lung DNA, collagen, and glycosaminoglycan synthesis, respectively, was also higher in CP groups. Increased levels of hydroxyproline, elastin, hexosamine, total hexose, fucose, sialic acid, and uronic acid in the lungs of rats 14, 28, and 42 days after CP insult were characterized as biomarkers of CP-induced interstitial changes. These findings indicate that CP-induced lung fibrosis results in alterations not only in collagen synthesis and accumulation, but also in glycosaminoglycan and glycoprotein content. 相似文献
170.
Ravi Jain Rajagopalan S. Li Fung Chang 《Selected Areas in Communications, IEEE Journal on》1997,15(1):96-105
Current cellular subscribers have a geographic phone number (e.g., in AMPS and US digital cellular systems) or a number which contains the network provider's identity (e.g., in GSM), and whenever subscribers register or receive (and possibly, originate) a call, a home location register (HLR) database has to be queried. The wired infrastructure supports a function called global title translation (GTT) that converts the subscriber's number to an HLR database address. A special feature of next generation wireless access service will be to support personal communication services (PCS) and wireless subscribers with portable personal numbers, or nongeographic phone numbers (NGPNs), that do not indicate the service provider or HLR database serving the user. In addition, the GTT function may not be available when the wired backbone is an ATM network. Thus a key function required in future wireless access systems with wired ATM backbones will be the ability to translate an NGPN to the identity of the HLR which serves the subscriber, a process we call NGPN translation. We discuss the requirements of NGPN translation and some alternative schemes. We propose two schemes for fast, efficient, scalable and flexible NGPN translation which use ideas of dynamic hashing, caching, and indirection. The schemes use a hash function in the visiting location registers (VLRs) (or serving SCP) and a set of distributed translation servers which store the NGPN-to-HLR mapping. We discuss how the operations required to maintain the translation information can be performed. Finally, we perform a simplified analysis of the scalability of the alternative schemes as well as the hash-based schemes we propose 相似文献