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991.
The capacity defines the ultimate fidelity limits of information transmission by any system. We derive the capacity of parallel Poisson process channels to judge the relative effectiveness of neural population structures. Because the Poisson process is equivalent to a Bernoulli process having small event probabilities, we infer the capacity of multi-channel Poisson models from their Bernoulli surrogates. For neural populations wherein each neuron has individual innervation, inter-neuron dependencies increase capacity, the opposite behavior of populations that share a single input. We use Shannon's rate-distortion theory to show that for Gaussian stimuli, the mean-squared error of the decoded stimulus decreases exponentially in both the population size and the maximal discharge rate. Detailed analysis shows that population coding is essential for accurate stimulus reconstruction. By modeling multi-neuron recordings as a sum of a neural population, we show that the resulting capacity is much less than the population's, reducing it to a level that can be less than provided with two separated neural responses. This result suggests that attempting neural control without spike sorting greatly reduces the achievable fidelity. In contrast, single-electrode neural stimulation does not incur any capacity deficit in comparison to stimulating individual neurons.  相似文献   
992.
This study presents an introduction to mass customization in the product life cycle—the goal of mass customization, mass customization configurations, and new customer integration techniques, modular design techniques, flexible manufacturing systems (FMSs), and supply chain management methods. The study reviews three selected books and twenty-one selected papers—early papers that describe the goal of mass customization, early papers that describe mass customization configurations, and recent papers that describe new customer integration techniques, modular design techniques, FMSs, and supply chain management methods. The study shows that the goal of mass customization is to create individually customized products, with mass production volume, cost, and efficiency, that most companies use ‘assemble-to-order’ configurations to create standardized products, and that more work is needed on interactive customer integration techniques, collaborative modular design techniques, reconfigurable manufacturing systems, and integrated supply chain management methods to achieve the goal of mass customization.  相似文献   
993.
Semi-formal design of reliable mesh generation systems   总被引:2,自引:0,他引:2  
A reliable mesh generation infrastructure is designed based on software engineering principles. Formal methods, software design documents and clear modular decomposition criteria are introduced to improve the quality of mesh generation software. The design document for a simple 2D mesh generation data structure is presented using a semi-formal specification. The proposed semi-formal documentation system avoids any ambiguity during the software design process and will help in driving the software test cases. Using the proposed software, design techniques result in a consistent software design that is easy to extend and modify.  相似文献   
994.
Existing face imaging systems are not suitable to meet the face representation and recognition demands for emerging applications in areas such as interactive gaming, enhanced learning environments and directed advertising. This is mainly due to the poor capture and characterisation of facial data that compromises their spatial and temporal precision. For emerging applications it is not only necessary to have a high level of precision for the representation of facial data, but also to characterise dynamic faces as naturally as possible and in a timely manner. This study proposes a new framework for capturing and recovering dynamic facial information in real-time at significantly high order of spatial and temporal accuracy to capture and model subtle facial changes for enhanced realism in 3D face visualisation and higher precision for face recognition applications. We also present a novel, fast, and robust correspondence mapping approach for 3D registration of moving 3D faces.  相似文献   
995.
Three studies tested the idea that when social identity is salient, group-based appraisals elicit specific emotions and action tendencies toward out-groups. Participants' group memberships were made salient and the collective support apparently enjoyed by the in-group was measured or manipulated. The authors then measured anger and fear (Studies 1 and 2) and anger and contempt (Study 3), as well as the desire to move against or away from the out-group. Intergroup anger was distinct from intergroup fear, and the inclination to act against the out-group was distinct from the tendency to move away from it. Participants who perceived the in-group as strong were more likely to experience anger toward the out-group and to desire to take action against it. The effects of perceived in-group strength on offensive action tendencies were mediated by anger. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
996.
This paper is concerned with methods for refinement of specifications written using a combination of Object-Z and CSP. Such a combination has proved to be a suitable vehicle for specifying complex systems which involve state and behaviour, and several proposals exist for integrating these two languages. The basis of the integration in this paper is a semantics of Object-Z classes identical to CSP processes. This allows classes specified in Object-Z to be combined using CSP operators. It has been shown that this semantic model allows state-based refinement relations to be used on the Object-Z components in an integrated Object-Z/CSP specification. However, the current refinement methodology does not allow the structure of a specification to be changed in a refinement, whereas a full methodology would, for example, allow concurrency to be introduced during the development life-cycle. In this paper, we tackle these concerns and discuss refinements of specifications written using Object-Z and CSP where we change the structure of the specification when performing the refinement. In particular, we develop a set of structural simulation rules which allow single components to be refined to more complex specifications involving CSP operators. The soundness of these rules is verified against the common semantic model and they are illustrated via a number of examples.  相似文献   
997.
The structured singular value μ gives a means of assessing the stability and performance of a system under a class of norm-bounded structured perturbations. This paper introduces a generalization of μ which guarantees stability with respect to perturbations, where some elements of the perturbation structure are bounded from above and some are bounded from below. This generalization is used to solve the frequency domain robust control model validation problem. Model validation determines whether or not there exist a model in the model set and a bounded noise signal that are consistent with the experimental input-output measurements. A computable convex upper bound to the generalized μ problem is presented, and the relationship between the generalized μ problem and the standard μ and model validation problems is discussed  相似文献   
998.
We present various 4-bit /spl times/ 4-bit unsigned multipliers designed using the delay-insensitive convention logic (NCL) paradigm. They represent bit-serial, iterative, and fully parallel multiplication architectures. NCL is a self-timed logic paradigm in which control is inherent in each datum. NCL follows the so-called weak conditions of Seitz's delay-insensitive signaling scheme. Like other delay-insensitive logic methods, the NCL paradigm assumes that forks in wires are isochronic. NCL uses symbolic completeness of expression to achieve delay-insensitive behavior. Simulation results show a large variance in circuit performance in terms of power, area, and speed. This study serve as a good reference for designers who wish to accomplish high-performance, low-power implementations of clockless digital VLSI circuits.  相似文献   
999.
Participants were 36 adolescents diagnosed with attention-deficit/hyperactivity disorder (ADHD) who completed a summer treatment program. Self-report measures included the IOWA Conners Inattention/Overactivity and Oppositional/Defiant subscales, peer and staff interaction ratings, and a daily guess if the placebo or methylphenidate was given during a double-blind medication trial. Self-reports were reliable, and some of the self-report measures distinguished between placebo and methylphenidate conditions. However, the self-report measures exhibited weak correlations with observed frequencies of negative behavior and did not make a unique contribution beyond what was reported by adults. This study replicates previous findings that adolescents may be poor sources of information about ADHD symptoms, but adolescents receiving treatment for ADHD may be able to provide valid self-reports about negative social behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
1000.
Measurement, inspection and quality control in industry have benefited from 3D techniques for imaging and visualization in recent years. The development of machine vision devices at decreased costs, as well as their miniaturization and integration in industrial processes, have accelerated the use of 3D imaging systems in industry. In this paper we describe how to improve the performance of a 3D imaging system for inline dimensional quality inspection of long, flat-rolled metal products manufactured in rolling mills we designed and developed in previous works. Two dimensional characteristics of rolled products are measured by the system: width and flatness. The system is based on active triangulation using a single-line pattern projected onto the surface of the product under inspection for range image acquisition. Taking the system calibration into account the range images are transformed into a calibrated point cloud representing the 3D surface reconstruction of the product. Two approaches to improve the line detection and extraction method used in the original system are discussed, one intended for high-speed processing with lower accuracy, and the other providing high accuracy while incurring higher computational time expenses. A mechanism to remove, or at least reduce, the effects of product movements while manufacturing, such as bouncing and flapping, is also proposed to improve the performance of the system.  相似文献   
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