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101.
Gianmarco de Felice Maria Antonietta Aiello Carmelo Caggegi Francesca Ceroni Stefano De Santis Enrico Garbin Natalino Gattesco Łukasz Hojdys Piotr Krajewski Arkadiusz Kwiecień Marianovella Leone Gian Piero Lignola Claudio Mazzotti Daniel Oliveira Corina Papanicolaou Carlo Poggi Thanasis Triantafillou Maria Rosa Valluzzi Alberto Viskovic 《Materials and Structures》2018,51(4):95
Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided. 相似文献
102.
Andrielli Morais de Oliveira Flávio de Andrade Silva Eduardo de Moraes Rego Fairbairn Romildo Dias Toledo Filho 《Materials and Structures》2018,51(3):65
This paper reports the experimental findings on the tensile behavior of strain-hardening cement-based composites (SHCC). The composites were subjected to the combined effects of elevated temperatures and internal moisture condition. Uniaxial tensile tests on dumbbell-shaped SHCC specimens with in situ temperature control were performed at 22, 60 and 100 °C. In addition, the effect of the internal humidity of SHCC (95, 50, 20 and 0%) coupled to the elevated temperatures was investigated. It was shown that the tensile strength decreases and the strain capacity increases with an increase in temperature. The influence of the internal moisture conditions was more significant in high temperatures. The strain capacity reduced significantly with a decrease in the humidity level. The crack pattern of the SHCC specimens was determined. Furthermore, single fiber pullout tests were performed under the considered high temperatures condition. Finally, the results are discussed based on the thermogravimetry analysis of the PVA fiber, alterations on its microstructure and surface coating. 相似文献
103.
A new method for the analysis of both total and bound SO(2) in wine is proposed, based on a quartz crystal microbalance (QCM), and it is compared with the widely used Ripper method. The proposed method is faster than the Ripper's, and the instrumentation is either home-made or widely available. When both methods are applied to the same sample, the results obtained using the QCM method are bracketed in an interval less than one-tenth the size of that obtained using the Ripper method. Although the SO(2) concentrations found using the QCM method correlate well with the ones obtained with the Ripper method, the results are systematically higher, which can be explained as due to the absence of interferences known to affect the Ripper method. 相似文献
104.
Luciano Oliveira Author Vitae Urbano Nunes Author Vitae Author Vitae Marco Silva Author Vitae Author Vitae 《Pattern recognition》2010,43(10):3648-3659
Fusion of laser and vision in object detection has been accomplished by two main approaches: (1) independent integration of sensor-driven features or sensor-driven classifiers, or (2) a region of interest (ROI) is found by laser segmentation and an image classifier is used to name the projected ROI. Here, we propose a novel fusion approach based on semantic information, and embodied on many levels. Sensor fusion is based on spatial relationship of parts-based classifiers, being performed via a Markov logic network. The proposed system deals with partial segments, it is able to recover depth information even if the laser fails, and the integration is modeled through contextual information—characteristics not found on previous approaches. Experiments in pedestrian detection demonstrate the effectiveness of our method over data sets gathered in urban scenarios. 相似文献
105.
This paper addresses the problem of position and attitude estimation, based on landmark readings and velocity measurements. A derivation of a nonlinear observer on SE(3) is presented, using a Lyapunov function conveniently expressed as a function of the difference between the estimated and the measured landmark coordinates. The resulting feedback laws are explicit functions of the landmark measurements and velocity readings, exploiting the sensor information directly in the observer. The proposed observer yields almost global asymptotic stabilization of the position and attitude errors and exponential convergence in any closed ball inside the region of attraction. Also, it is shown that the asymptotic convergence of the estimation error trajectories is shaped by the landmark geometry and observer design parameters. The problem of non-ideal velocity readings is also considered, and the observer is augmented to compensate for bias in the angular and linear velocity measurements. The resulting position, attitude, and bias estimation errors are shown to converge exponentially fast to the desired equilibrium points, for bounded initial estimation errors. Simulation results are presented to illustrate the stability and convergence properties of the observer. 相似文献
106.
Ricardo V. de Oliveira Rodrigo A. Ramos Newton G. Bretas 《Control Engineering Practice》2010,18(1):45-54
The main objective of this paper is to relieve the power system engineers from the burden of the complex and time-consuming process of power system stabilizer (PSS) tuning. To achieve this goal, the paper proposes an automatic process for computerized tuning of PSSs, which is based on an iterative process that uses a linear matrix inequality (LMI) solver to find the PSS parameters. It is shown in the paper that PSS tuning can be written as a search problem over a non-convex feasible set. The proposed algorithm solves this feasibility problem using an iterative LMI approach and a suitable initial condition, corresponding to a PSS designed for nominal operating conditions only (which is a quite simple task, since the required phase compensation is uniquely defined). Some knowledge about the PSS tuning is also incorporated in the algorithm through the specification of bounds defining the allowable PSS parameters. The application of the proposed algorithm to a benchmark test system and the nonlinear simulation of the resulting closed-loop models demonstrate the efficiency of this algorithm. 相似文献
107.
R. Guadagnin L. Santana E. Ferneda H. Prado 《Pattern Recognition and Image Analysis》2010,20(1):81-85
Geoprocessing Information Systems (GIS) deal with structured information concerned some geographical localization. So one
uses three-dimensional image representation systems in a huge database, where it is possible to insert many data about some
interest domain, say, agriculture, economics, industry, demographics and so on. Images are powerful information sources that
can soundly support decision making processes. An image can be seen as a set of elements with spatial localization and color.
To interpret an image includes deriving clusters and relations between such elements. This article proposes an integration
of Geoprocessing and Image Mining to support image based decisions in several domains such as healthcare. 相似文献
108.
Mauri Aparecido de Oliveira 《Neural computing & applications》2011,20(5):687-701
The objective of this article is to find out the influence of the parameters of the ARIMA-GARCH models in the prediction of
artificial neural networks (ANN) of the feed forward type, trained with the Levenberg–Marquardt algorithm, through Monte Carlo
simulations. The paper presents a study of the relationship between ANN performance and ARIMA-GARCH model parameters, i.e.
the fact that depending on the stationarity and other parameters of the time series, the ANN structure should be selected
differently. Neural networks have been widely used to predict time series and their capacity for dealing with non-linearities
is a normally outstanding advantage. However, the values of the parameters of the models of generalized autoregressive conditional
heteroscedasticity have an influence on ANN prediction performance. The combination of the values of the GARCH parameters
with the ARIMA autoregressive terms also implies in ANN performance variation. Combining the parameters of the ARIMA-GARCH
models and changing the ANN’s topologies, we used the Theil inequality coefficient to measure the prediction of the feed forward
ANN. 相似文献
109.
Paulo Anselmo da Mota Silveira Neto Ivan do Carmo Machado John D. McGregorEduardo Santana de Almeida Silvio Romero de Lemos Meira 《Information and Software Technology》2011,53(5):407-423
Context
In software development, Testing is an important mechanism both to identify defects and assure that completed products work as specified. This is a common practice in single-system development, and continues to hold in Software Product Lines (SPL). Even though extensive research has been done in the SPL Testing field, it is necessary to assess the current state of research and practice, in order to provide practitioners with evidence that enable fostering its further development.Objective
This paper focuses on Testing in SPL and has the following goals: investigate state-of-the-art testing practices, synthesize available evidence, and identify gaps between required techniques and existing approaches, available in the literature.Method
A systematic mapping study was conducted with a set of nine research questions, in which 120 studies, dated from 1993 to 2009, were evaluated.Results
Although several aspects regarding testing have been covered by single-system development approaches, many cannot be directly applied in the SPL context due to specific issues. In addition, particular aspects regarding SPL are not covered by the existing SPL approaches, and when the aspects are covered, the literature just gives brief overviews. This scenario indicates that additional investigation, empirical and practical, should be performed.Conclusion
The results can help to understand the needs in SPL Testing, by identifying points that still require additional investigation, since important aspects regarding particular points of software product lines have not been addressed yet. 相似文献110.
Alvaro E. Cuno Parari Claudio Esperança Antonio A. F. Oliveira 《The Visual computer》2009,25(10):911-922
This work presents methods for deforming meshes in a shape-sensitive way using Moving Least Squares (MLS) optimization. It
extends an approach for deforming space (Cuno et al. in Proceedings of the 27th Computer Graphics International Conference,
pp. 115–122, 2007) by showing how custom distance metrics may be used to achieve deformations which preserve the overall mesh shape. Several
variant formulations are discussed and demonstrated, including the use of geodesic distances, distances constrained to paths
contained in the mesh, the use of skeletons, and a reformulation of the MLS scheme which makes it possible to affect the bending
behavior of the deformation. Finally, aspects of the implementation of these techniques in parallel architectures such as
GPUs (graphics processing units) are described and compared with CPU-only implementations. 相似文献