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971.
Dubois A  Canva M  Brun A  Chaput F  Boilot JP 《Applied optics》1996,35(18):3193-3199
The photostability of dye molecules trapped in transparent solid matrices synthesized by the solgel technique was studied both experimentally and theoretically using a model with numerical and approximate analytical solutions. The model is based on a one-photon photodestruction process with the creation of an absorbing bleached molecule. We give the number of photons that different trapped dye molecules can absorb on average before they are bleached. Dyes such as Perylene Red, Perylene Orange, Pyrromethenes 567 and 597, Rhodamines 6G and B, DCM, a Xanthylium salt, and Neon Red were investigated; significant differences were observed. Some dye molecules in solvents were also studied; increased stability resulted when the molecules were trapped in solid matrices.  相似文献   
972.
Minetti C  Dubois F 《Applied optics》1996,35(11):1900-1903
We propose an automatic spatial frequency selection correlation filter that reduces the sensitivity to nonoverlapping noise or background clutter. This is achieved by inclusion of distorted versions of the reference images surrounded by nonoverlapping background clutter. Furthermore, we impose that the window functions of the reference images give response zero-correlation amplitudes. Simulation results are provided in the case of a two-class pattern-recognition problem and show that the results are appreciably increased. The results are compared with a normal automatic spatial frequency selection.  相似文献   
973.
Dubois F 《Applied optics》1996,35(23):4589-4597
A recognition process consisting of two cascaded correlation stages with a sigmoid nonlinearity applied in the first correlation plane is investigated. The filters are computed to give prespecified central correlation amplitudes in the second correlation plane when inputs are reference images. It is also desired that the second correlation amplitudes with the training images should minimize the cost function of the automatic spatial-frequency selection algorithm to reduce distortion sensitivity and to improve the performance of the filters. Filter computation methods are given, and it is shown why two such correlation processes may improve the correlation performance. Numerical simulations are described and compared with the one-stage correlation system that works with the automatic spatial-frequency selection filter.  相似文献   
974.
Sensing is the process of detecting and monitoring any physico-chemical environmental parameters. Herein, new self-powered iontronic sensors, which utilize touch-induced ionic charge separation in ionically conductive hydrogels, are introduced for potential use in object mapping, recognition, and localization. This is accomplished using high-resolution stereolithography (SLA) 3D printing of stacked ionic assemblies consisting of discrete compartments having different ion transport properties. The latter assemblies readily allow programming the output voltage magnitude and polarity by means of variations in ion type, charge density, and cross-linking density within the iontronic device. Voltages of up to 70 mV are generated on application of compressive strains of as much as 50% (≈22.5 kPa), with the magnitude directly proportional to stress, and the polarity dependent on the sign of the mobile ion. As a proof-of-concept demonstration, the resulting touch sensors are integrated on the fingertip to enable the tactile feedback, mimicking the tactile perception of objects for recognition applications. In addition, it is proposed that streaming potential is the underlying mechanism behind the iontronic touch sensors. The electromechanical response is therein consistent with a streaming potential model.  相似文献   
975.
Polymerization of acetoxy-2 styrene, parachloro acetoxy-2 styrene, paramethyl acetoxy-2 styrene and paranitro acetoxy-2 styrene was carried out by means of free radical initiators or by thermic reaction. The polymers therefrom showed molecular weights of about 200 000. Studies on the thermal behaviour reveal that these polymers do not undergo any change of phase, either vitreous or crystalline. Dielectric experiments show losses of about 10?3 radian; the losses are practically constant within a large scale of temperature and frequency. Over 320°K one notices a relaxation process of small magnitude and the presence of water brings about a marked change in the way the polymer reacts to dielectric treatment.  相似文献   
976.
Understanding how software systems evolve is useful from different perspectives: reverse engineering, empirical studies etc.. For an effective understanding we need an explicit meta-model. We introduce Hismo, a meta-model which is centered around the notion of history and we show how we can obtain it from a snapshot meta-model. Based on our experience in developing the Hismo reverse engineering system, we show how we can transform a snapshot meta-model in a history meta-model.  相似文献   
977.
Gradual Numbers and Their Application to Fuzzy Interval Analysis   总被引:1,自引:0,他引:1  
In this paper, we introduce a new way of looking at fuzzy intervals. Instead of considering them as fuzzy sets, we see them as crisp sets of entities we call gradual (real) numbers. They are a gradual extension of real numbers, not of intervals. Such a concept is apparently missing in fuzzy set theory. Gradual numbers basically have the same algebraic properties as real numbers, but they are functions. A fuzzy interval is then viewed as a pair of fuzzy thresholds, which are monotonic gradual real numbers. This view enables interval analysis to be directly extended to fuzzy intervals, without resorting to alpha-cuts, in agreement with Zadeh's extension principle. Several results show that interval analysis methods can be directly adapted to fuzzy interval computation where end- points of intervals are changed into left and right fuzzy bounds. Our approach is illustrated on two known problems: computing fuzzy weighted averages and determining fuzzy floats and latest starting times in activity network scheduling.  相似文献   
978.
This paper describescoordination relations, that are relations that induce the presence or absence of data on some dataspaces from the presence or absence of other data on other dataspaces. To that end we build upon previous work on the μLog model and show that the coordination relations can be easily incorporated in it. This is achieved, on the one hand, by means of novel auxiliary operations, not classically used in Linda-like languages, and, on the other hand, by a translation technique reducing the extended μLog model to the core model augmented with the auxiliary operations. Among the most significant ones are multiple read and get operations on a blackboard, readall and getall operations, and tests for the absence of data on blackboards. Although simple, the form of coordination relations we propose is quite powerful as evidenced by a few examples including relations coming from the object-oriented paradigm such as inheritance relations. Jean-Marie Jacquet, Ph.D.: He is Professor at the Institute of Informatics at the University of Namur, Belgium, and, at an honorary title, Research Associate of the Belgian National Fund for Scientific Research. He obtained a Master in Mathematics from the University of Liège in 1982, a Master in Computer Science from the University of Namur in 1984 and a Ph.D. in Computer Science from the University of Namur in 1989. His research interest are in Programming Languages and Coordination models. He has served as a reviewer and program committee member of several conferences. Koen de Bosschere, Ph.D.: He holds the degree of master of Science in Engineering of the Ghent University, and a Ph.D. from the same University. He is currently research associate with the Fund for Scientific Research — Flanders and senior lecturer at the Ghent University, where he teaches courses on computer architecture, operating systems and declarative programming languages. His research interests are coordination in parallel logic programming, computer architecture and systems software.  相似文献   
979.
This paper investigates the possibility of performing automated reasoning in probabilistic knowledge bases when probabilities are expressed by means of linguistic quantifiers. Data are expressed in terms of ill-known conditional probabilities represented by linguistic terms. Each linguistic term is expressed as a prescribed interval of proportions. Then instead of propagating numbers, qualitative terms are propagated in accordance with the numerical interpretation of these terms. The quantified syllogism, modeling the chaining of probabilistic rules, is studied in this context. It is shown that a qualitative counterpart of this syllogism makes sense and is fairly independent of the thresholds defining the linguistically meaningful intervals, provided that these threshold values remain in accordance with the intuition. The inference power is less than a full-fledged probabilistic constraint propagation device but corresponds better to what could be thought of as commonsense probabilistic reasoning. Suggestions that may improve the inferencing power in the qualitative setting are proposed.This paper is an extended and revised version of a paper entitled A Symbolic Approach to Reasoning with Linguistic Quantifiers inProc. 8th Conf. Uncertainty in Artificial Intelligence Dubois, D., Wellman, M.P., D'Ambrosio, B., and Smets, Ph. (Eds.), Morgan Kaufmann, pp. 74–82, 1992.  相似文献   
980.
Although epoxy resins exhibit a wide range of useful properties for protective coatings on metal substrates, an increasing trend in the coatings industry toward more formable coatings places a severe burden on the traditional bisphenol. A based epoxy resins. Presented in this work are the results of experiments with a new series of epoxy resins based on alkylenedioxy diphenols demonstrating the relationship between coating performance properties (formability, chemical resistance, and adhesion) and structural parameters such as resin backbone flexibility, degree of phenol/formaldehyde crosslinkmg, and concentration of OH groups in the backbone of epoxy resins. Optimizing the three structural parameters for the new resins results in substantial improvements in coating performance properties over the traditional bisphenol A based resins.  相似文献   
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