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191.
Comprehending and debugging computer programs are inherently difficult tasks. The current approach to building program execution
and debugging environments is to use exclusively visual stimuli on programming languages whose syntax and semantics has often
been designed without empirical guidance. We present an alternative: Sodbeans, an open-source integrated development environment
designed to output carefully chosen spoken auditory cues to supplement empirically evaluated visual stimuli. Originally designed
for the blind, earlier work suggested that Sodbeans may benefit sighted programmers as well. We evaluate Sodbeans in two experiments.
First, we report on a formal debugging experiment comparing (1) a visual debugger, (2) an auditory debugger, and (3) a multimedia
debugger, which includes both visual and auditory stimuli. The results from this study indicate that while auditory debuggers
on their own are significantly less effective for sighted users when compared with visual and multimedia debuggers, multimedia
debuggers might benefit sighted programmers under certain circumstances. Specifically, we found that while multimedia debuggers
do not provide instant usability, once programmers have some practice, their performance in answering comprehension questions
improves. Second, we created and evaluated a pilot survey analyzing individual elements in a custom programming language (called
HOP) to garner empirical metrics on their comprehensibility. Results showed that some of the most widely used syntax and semantics
choices in commercial programming languages are extraordinarily unintuitive for novices. For example, at an aggregate level,
the word
for
, as in a
for
loop, was rated reliably worse than
repeat
by more than 673% by novices. After completing our studies, we implemented the HOP programming language and integrated it
into Sodbeans. 相似文献
192.
Vasiliki L. KakaliPanagiotis G. Sarigiannidis Georgios I. Papadimitriou Andreas S. Pomportsis 《Computers & Mathematics with Applications》2011,62(1):474-485
A new machine learning framework is introduced in this paper, based on the hidden Markov model (HMM), designed to provide scheduling in dynamic wireless push systems. In realistic wireless systems, the clients’ intentions change dynamically; hence a cognitive scheduling scheme is needed to estimate the desirability of the connected clients. The proposed scheduling scheme is enhanced with self-organized HMMs, supporting the network with an estimated expectation of the clients’ intentions, since the system’s environment characteristics alter dynamically and the base station (server side) has no a priori knowledge of such changes. Compared to the original pure scheme, the proposed machine learning framework succeeds in predicting the clients’ information desires and overcomes the limitation of the original static scheme, in terms of mean delay and system efficiency. 相似文献
193.
Andreas Birk Burkhard Wiggerich Heiko Bülow Max Pfingsthorn Sören Schwertfeger 《Journal of Intelligent and Robotic Systems》2011,64(1):57-76
Several missions with an Unmanned Aerial Vehicle (UAV) in different realistic safety, security, and rescue field tests are
presented. First, results from two safety and security missions at the 2009 European Land Robot Trials (ELROB) are presented.
A UAV in form of an Airrobot AR100-B is used in a reconnaissance and in a camp security scenario. The UAV is capable of autonomous
waypoint navigation using onboard GPS processing. A digital video stream from the vehicle is used to create photo maps—also
known as mosaicking—in real time at the operator station. This mapping is done using an enhanced version of Fourier Mellin
based registration, which turns out to be very fast and robust. Furthermore, results from a rescue oriented scenario at the
2010 Response Robot Evaluation Exercises (RREE) at Disaster City, Texas are presented. The registration for the aerial mosaicking
is supplemented by an uncertainty metric and embedded into Simultaneous Localization and Mapping (SLAM), which further enhances
the photo maps as main mission deliveries. 相似文献
194.
3D mapping is very challenging in the underwater domain, especially due to the lack of high resolution, low noise sensors.
A new spectral registration method is presented that can determine the spatial 6 DOF transformation between pairs of very
noisy 3D scans with only partial overlap. The approach is hence suited to cope with sonar as the predominant underwater sensor.
The spectral registration method is based on Phase Only Matched Filtering (POMF) on non-trivially resampled spectra of the
3D data. 相似文献
195.
The combination of backstepping-based state-feedback control and flatness-based trajectory planning and feedforward control is considered for the design of an exponentially stabilizing tracking controller for a linear diffusion-convection-reaction system with spatially and temporally varying parameters and nonlinear boundary input. For this, in a first step the backstepping transformation is utilized to determine a state-feedback controller, which transforms the original distributed-parameter system into an appropriately chosen exponentially stable distributed-parameter target system of a significantly simpler structure. In a second step, the flatness property of the target system is exploited in order to determine the feedforward controller, which allows us to realize the tracking of suitably prescribed trajectories for the system output. This results in a systematic procedure for the design of an exponentially stabilizing tracking controller for the considered general linear diffusion-convection-reaction system with varying parameters, whose applicability and tracking performance is evaluated in simulation studies. 相似文献
196.
We propose a mathematical model for the Towers of Hanoi and London based on state graphs. The analysis of this model allows to address questions like equivalence of puzzles, difficulty of tasks and optimality of solutions using topological, metric and symmetry properties of the corresponding graphs.The mathematical model serves as a base for a computer program to administer tower puzzles in a variety of psychological test situations. It is suitable for bedside use and is equipped with numerous devices for post-processing of recorded data. Among these features is the graphical representation of the projection of the path taken by a test person onto the state graph. 相似文献
197.
A famous lower bound for the bilinear complexity of the multiplication in associative algebras is the Alder–Strassen bound. Algebras for which this bound is tight are called algebras of minimal rank. After 25 years of research, these algebras are now well understood. Here we start the investigation of the algebras for which the Alder–Strassen bound is off by one. As a first result, we completely characterize the semisimple algebras over R whose bilinear complexity is by one larger than the Alder–Strassen bound. Furthermore, we characterize all algebras A (with radical) of minimal rank plus one over R for which A/radA has minimal rank plus one. The other possibility is that A/radA has minimal rank. For this case, we only present a partial result. 相似文献
198.
In a graph, a vertex is simplicial if its neighborhood is a clique. For an integer k≥1, a graph G=(VG,EG) is the k-simplicial power of a graph H=(VH,EH) (H a root graph of G) if VG is the set of all simplicial vertices of H, and for all distinct vertices x and y in VG, xyEG if and only if the distance in H between x and y is at most k. This concept generalizes k-leaf powers introduced by Nishimura, Ragde and Thilikos which were motivated by the search for underlying phylogenetic trees; k-leaf powers are the k-simplicial powers of trees. Recently, a lot of work has been done on k-leaf powers and their roots as well as on their variants phylogenetic roots and Steiner roots. For k≤5, k-leaf powers can be recognized in linear time, and for k≤4, structural characterizations are known. For k≥6, the recognition and characterization problems of k-leaf powers are still open. Since trees and block graphs (i.e., connected graphs whose blocks are cliques) have very similar metric properties, it is natural to study k-simplicial powers of block graphs. We show that leaf powers of trees and simplicial powers of block graphs are closely related, and we study simplicial powers of other graph classes containing all trees such as ptolemaic graphs and strongly chordal graphs. 相似文献
199.
Changes in the microstructure of materials and their impact on reliability: experiments and modeling
Several types of microstructural changes in microelectronic solder materials are briefly discussed, namely the formation of
intermetallics, Kirkendall voiding, spinodal decomposition, and coarsening. Moreover, a theoretical framework, based on the
entropy principle, is developed by means of which constitutive equations can be derived that are necessary to understand and
simulate such processes. The resulting equations are specialized to binary alloys and then investigated numerically. Finally,
simulations of spinodal decomposition and coarsening are performed for the eutectic solder AgCu. The theoretical predictions
are compared with experiments.
相似文献
Andreas BrandmairEmail: |
Wolfgang H. Müller (Corresponding author)Email: |
200.