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91.
92.
We present a non-linear 2-D/2-D affine registration technique for MR and CT modality images of section of human brain. Automatic
registration is achieved by maximization of a similarity metric, which is the correlation function of two images. The proposed
method has been implemented by choosing a realistic, practical transformation and optimization techniques. Correlation-based
similarity metric should be maximal when two images are perfectly aligned. Since similarity metric is a non-convex function
and contains many local optima, choice of search strategy for optimization is important in registration problem. Many optimization
schemes are existing, most of which are local and require a starting point. In present study we have implemented genetic algorithm
and particle swarm optimization technique to overcome this problem. A comparative study shows the superiority and robustness
of swarm methodology over genetic approach. 相似文献
93.
We consider three different communication tasks for quantum broadcast channels, and we determine the capacity region of a Hadamard broadcast channel for these various tasks. We define a Hadamard broadcast channel to be such that the channel from the sender to one of the receivers is entanglement-breaking and the channel from the sender to the other receiver is complementary to this one. As such, this channel is a quantum generalization of a degraded broadcast channel, which is well known in classical information theory. The first communication task we consider is classical communication to both receivers, the second is quantum communication to the stronger receiver and classical communication to other, and the third is entanglement-assisted classical communication to the stronger receiver and unassisted classical communication to the other. The structure of a Hadamard broadcast channel plays a critical role in our analysis: The channel to the weaker receiver can be simulated by performing a measurement channel on the stronger receiver’s system, followed by a preparation channel. As such, we can incorporate the classical output of the measurement channel as an auxiliary variable and solve all three of the above capacities for Hadamard broadcast channels, in this way avoiding known difficulties associated with quantum auxiliary variables. 相似文献
94.
By exploiting the unattended nature of the wireless sensor networks, an attacker can physically capture and compromise sensor nodes and then launch a variety of attacks. He can additionally create many replicas of a few compromised nodes and spread these replicas over the network, thus launching further attacks with their help. In order to minimize the damage incurred by compromised and replicated nodes, it is very important to detect such malicious nodes as quickly as possible. In this review article, we synthesize our previous works on node compromise detection in sensor networks while providing the extended analysis in terms of performance comparison to the related work. More specifically, we use the methodology of the sequential analysis to detect static and mobile compromised nodes, as well as mobile replicated nodes in sensor networks. With the help of analytical and simulation results, we also demonstrate that our schemes provide robust and efficient node compromise detection capability. 相似文献
95.
Das S. Abraham A. Konar A. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2008,38(1):218-237
Differential evolution (DE) has emerged as one of the fast, robust, and efficient global search heuristics of current interest. This paper describes an application of DE to the automatic clustering of large unlabeled data sets. In contrast to most of the existing clustering techniques, the proposed algorithm requires no prior knowledge of the data to be classified. Rather, it determines the optimal number of partitions of the data "on the run." Superiority of the new method is demonstrated by comparing it with two recently developed partitional clustering techniques and one popular hierarchical clustering algorithm. The partitional clustering algorithms are based on two powerful well-known optimization algorithms, namely the genetic algorithm and the particle swarm optimization. An interesting real-world application of the proposed method to automatic segmentation of images is also reported. 相似文献
96.
Presents new methods for lossless predictive coding of medical images using two dimensional multiplicative autoregressive models. Both single-resolution and multi-resolution schemes are presented. The performances of the proposed schemes are compared with those of four existing techniques. The experimental results clearly indicate that the proposed schemes achieve higher compression compared to the lossless image coding techniques considered. 相似文献
97.
The oxidation kinetics of CuFeO2 in the Cu-Fe-O system have been studied between 500 and 900° C in an atmosphere containing 1 vol% oxygen in a nitrogen stream using thermogravimetric analysis (TGA). It was found that addition of Fe2O3 to the CuFeO2 caused a decrease in the oxidation rate while addition of CuO caused an increase. On increasing the concentration of Fe2O3 the activation energy was found to increase from ~ 18 kcal mol–1 to ~ 45 kcal mol–1 and the exponent n in Avrami's equationf=1-exp (–kt
n) was also observed to increase, from 1.3 to 2.3. On adding CuO to the CuFeO2 in the Cu-Fe-O system the activation energy decreased from ~ 18 kcal mol–1 to ~ 8 kcal mol–1. The variation in both values indicates changes in the oxidation mechanisms. The microstructural changes associated with oxidation have been studied using optical microscopy. A model has been proposed to explain the results. 相似文献
98.
Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated. In addition, the parameters, viz. drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant. The study revealed that addition of only 5 × 10?6 of Sodium Carboxymethyl Cellulose (Na-CMC) flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash. Besides, it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing. The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle–particle bridging. This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines. 相似文献
99.
Cabral RM Ferraz MS Rizzo M Sousa FD Rodrigues NM Ibiapina PB Ambrósio CE De Carvalho MA 《Microscopy research and technique》2012,75(5):566-570
The aim of this study is to show histological and immunofluorescence analysis of renal parenchyma of agoutis affected by gentamicin‐induced renal disease after the infusion of bone marrow mononuclear cells (BMMC) stained with Hoechst®. Nine agouti's males were divided into three groups: Test group (TG): renal disease by gentamicin induced (n = 3), cell therapy group (CTG): renal disease by gentamicin induced and BMMC infusion (n = 3), and control group (CG): nonrenal disease and BMMC infusion (n = 3). TG and CTG were submitted to the protocol of renal disease induction using weekly application of gentamicin sulfate for 4 months. CG and CTG received a 1 × 108 BMMC stained with Hoechst and were euthanized for kidney examination 21 days after BMMC injection and samples were collected for histology and immunofluorescence analysis. Histological analysis demonstrated typical interstitial lesions in kidney similarly to human disease, as tubular necrosis, glomerular destruction, atrophy tubular, fibrotic areas, and collagen deposition. We conclude that histological analysis suggest a positive application of agouti's as a model for a gentamicin inducing of kidney disease, beyond the immunofluorescence analysis suggest a significant migration of BMMC to sites of renal injury in CTG. Microsc. Res. Tech., 2012. © 2011 Wiley Periodicals, Inc. 相似文献
100.
An inertia-adaptive particle swarm system with particle mobility factor for improved global optimization 总被引:2,自引:2,他引:0
Sayan Ghosh Swagatam Das Debarati Kundu Kaushik Suresh B. K. Panigrahi Zhihua Cui 《Neural computing & applications》2012,21(2):237-250
Particle Swarm Optimization (PSO) has recently emerged as a nature-inspired algorithm for real parameter optimization. This
article describes a method for improving the final accuracy and the convergence speed of PSO by firstly adding a new coefficient
(called mobility factor) to the position updating equation and secondly modulating the inertia weight according to the distance
between a particle and the globally best position found so far. The two-fold modification tries to balance between the explorative
and exploitative tendencies of the swarm with an objective of achieving better search performance. We also mathematically
analyze the effect of the modifications on the dynamics of the PSO algorithm. The new algorithm has been shown to be statistically
significantly better than the basic PSO and four of its state-of-the-art variants on a twelve-function test-suite in terms
of speed, accuracy, and robustness. 相似文献