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271.
The Visual Semantic Web (ViSWeb) is a new paradigm for enhancing the current Semantic Web technology. Based on Object-Process Methodology (OPM), which enables modeling of systems in a single graphic and textual model, ViSWeb provides for representation of knowledge over the Web in a unified way that caters to human perceptions while also being machine processable. The advantages of the ViSWeb approach include equivalent graphic-text knowledge representation, visual navigability, semantic sentence interpretation, specification of system dynamics, and complexity management. Arguing against the claim that humans and machines need to look at different knowledge representation formats, the principles and basics of various graphic and textual knowledge representations are presented and examined as candidates for ViSWeb foundation. Since OPM is shown to be most adequate for the task, ViSWeb is developed as an OPM-based layer on top of XML/RDF/OWL to express knowledge visually and in natural language. Both the graphic and the textual representations are strictly equivalent. Being intuitive yet formal, they are not only understandable to humans but are also amenable to computer processing. The ability to use such bimodal knowledge representation is potentially a major step forward in the evolution of the Semantic Web.Received: 14 December 2002, Accepted: 28 November 2003, Published online: 6 February 2004Edited by: V. AtluriDov Dori: dori@ie.technion.ac.il  相似文献   
272.
Rating scales relating to the individual's past, present, and future were administered to Ss (aged 60–90 yrs); those who completed all ratings (N?=?589) were compared with others who specifically failed to rate the future (N?=?150). The groups were differentiated by age, gender, health, and marital status. Total subjective well-being did not differ, but specific subjective well-being factors concerning time and aging could serve as discriminators. These differences suggest that these older adults might be apprehensive about their future and that skipping future-related questions is a genuine reaction with both psychological and methodological implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
273.
274.
Of concern is an environment made up of signals and systems tightly confined both in time and frequency. Such an environment is often encountered in transmission line circuits, radar, sonar, and optical circuits, and when the principal signals are well-defined sharp pulses. It will be seen that once this environment is achieved, the signals and systems possess some attractive properties. A conventional system may preserve the symmetry of a propagating signal or change its symmetry from even to odd or from odd to even. Another system may be used to predict the arrival of an incoming pulse with a high degree of accuracy. Electrical networks may also be associated with these properties. Approximation problems, existence theorems, and realization schemes will be addressed and developed.  相似文献   
275.
Of concern is the undistorted propagation of pulse stress waves in long thin bodies. The primary signals are arbitrarily sharp pulses projected along thex-axis. It will be seen that these pulses travel close to the speed of sound in unbounded media. Secondary pulses follow representing interactive disturbances traveling along they-axis. But the process brings out certain anomalies in circuit realizability requirements. These issues, transmission parameters, and coupling between the various signals are studied in detail. The results are supported by experiments.Work supported by TecSonics Inc., Twinsburg Ohio.  相似文献   
276.
A cost-benefit approach is employed to model the discretionary use of a computerized information system. The model is constructed by integrating a systemic view of human-computer interaction with a contingency model for selecting decision strategies. It is then used to analyse the effect of presentation format on search behaviour.

An experiment on matchmaking was performed using two formats: sequential and parallel. Subjects were asked to find the best spouse for a candidate using an information retrieval system that displayed information about the individuals according to the subject's specific requests. The subject's search behaviour and perception of complexity were recorded. A first analysis of the protocols revealed different behaviours, as predicted by the cost-benefit mechanism. A second analysis incorporated a measure of individual differences in perception to gain a better understanding of the effects of display format on perceived complexity and, thereby, on behaviour. The findings support the use or the cost-benefit model. The design implications of the model are also discussed.  相似文献   
277.
A general method of regression analysis of the experimental data concerning relaxation experiments on binary compounds for the evaluation of the chemical diffusion coefficient is presented for cases in which the surface reaction exerts a partial control of the overall equilibration kinetics, assuming that the surface reaction follows a linear type of rate law. A rigorous method of analysis of data for the case of exclusive rate control by solid-state diffusion is also developed as a special solution. Application of the method to theoretically calculated curves indicates the correctness of the procedure developed. Limitations connected with the possible occurrence of forms different from the linear for the surface rate law are finally considered.  相似文献   
278.
The object-process methodology (OPM) specifies both graphically and textually the system's static-structural and behavioral-procedural aspects through a single unifying model. This model singularity is contrasted with the multimodel approach applied by existing object oriented system analysis methods. These methods usually employ at least three distinct models for specifying various system aspects: mainly structure, function, and behavior. Object modeling technique (OMT), the main ancestor of the unified modeling language (UML), extended with timed statecharts, represents a family of such multimodal object oriented methods. Two major open questions related to model multiplicity vs. model singularity have been: 1) whether or not a single model, rather than a combination of several models, enables the synthesis of a better system specification; and 2) which of the two alternative approaches yields a specification that is easier to comprehend. The authors address these questions through a double-blind controlled experiment. To obtain conclusive results, real time systems, which exhibit a more complex dynamic behavior than nonreal time systems were selected as the focus of the experiment. We establish empirically that a single model methodology, OPM, is more effective than a multimodel one, OMT, in terms of synthesis. We pinpoint specific issues in which significant diiferences between the two methodologies were found. The specification comprehension results show that there were significant differences between the two methods in specific issues  相似文献   
279.
Object-Process Methodology (OPM), which is a holistic approach to modeling and evolving systems, views objects and processes as two equally important entities that describe the system's structure and behavior in a single model. Unified Modeling Language (UML), which is the standard object-oriented modeling language for software systems, separates the system model into various aspects, each of which is represented in a different view (diagram type).The exponential growth of the Web and the progress of Internet-based architectures have set the stage for the proliferation of a variety of Web applications, which are classified as hybrids between hypermedia and information systems. Such applications require a modeling approach that is capable of clearly specifying aspects of their architecture, communication, and distributive nature. Since UML and OPM are two candidates for this task, this study has been designed to establish the level of comprehension and the quality of the constructed Web application models using each one of these two approaches.In the experiment we carried out, third year undergraduate information systems engineering students were asked to respond to comprehension and construction questions about two representative Web application models. The comprehension questions related to the system's structure, dynamics, and distribution aspects. The results suggest that OPM is better than UML in modeling the dynamics aspect of the Web applications. In specifying structure and distribution aspects, there were no significant differences. The results further suggest that the quality of the OPM models students built in the construction part was superior to that of the corresponding UML models.  相似文献   
280.
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