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171.
A.H. Gnauck S. Chandrasekhar P.J. Winzer 《Photonics Technology Letters, IEEE》2006,18(5):697-699
We experimentally demonstrate a 10.7-Gb/s duobinary transmission system operating over a chromatic-dispersion range of /spl sim/12 000 ps/nm. Heterodyne detection and maximum-likelihood sequence estimation are employed to achieve this result. 相似文献
172.
A common computing-core representation of the discrete cosine transform and discrete sine transform is derived and a reduced-complexity algorithm is developed for computation of the proposed computing-core. A parallel architecture based on the principle of distributed arithmetic is designed further for the computation of these transforms using the common-core algorithm. The proposed scheme not only leads to a systolic-like regular and modular hardware for computing these transforms, but also offers significant improvement in area-time efficiency over the existing structures. The structure proposed here is devoid of complicated input/output mapping and does not involve any complex control. Unlike the convolution-based structures, it does not restrict the transform length to be a prime or multiple of prime and can be utilized as a reusable core for cost-effective, memory-efficient, high-throughput implementation of either of these transforms 相似文献
173.
Piedade M. Sousa L. A. de Almeida T. M. Germano J. da Costa B. A. Lemos J. M. Freitas P. P. Ferreira H. A. Cardoso F. A. 《IEEE transactions on circuits and systems. I, Regular papers》2006,53(11):2384-2395
This paper presents a hand-held microsystem based on new fully integrated magnetoresistive biochips for biomolecular recognition (DNA hybridization, antibody antigen interaction, etc.). Magnetoresistive chip surfaces are chemically treated, enabling the immobilization of probe biomolecules such as DNA or antibodies. Fluid handling is also integrated in the biochip. The proposed microsystem not only integrates the biochip, which is an array of 16times16 magnetoresistive sensors, but it also provides all the electronic circuitry for addressing and reading out each transducer. The proposed architecture and circuits were specifically designed for achieving a compact, programmable and portable microsystem. The microsystem also integrates a hand-held analyzer connected through a wireless channel. A prototype of the system was already developed and detection of magnetic nanoparticles was obtained. This indicates that the system may be used for magnetic label based bioassays 相似文献
174.
N. P. Yeliseyeva 《Journal of Communications Technology and Electronics》2006,51(4):380-384
Rigorous analytic expressions for radiation resistance R Σ of an electric dipole are obtained for three mutually orthogonal orientations of the dipole’s axis with respect to a plane metal screen or right-angle corner of infinite dimensions. Radiation resistance R Σ of the dipole oriented arbitrarily in space is calculated and analyzed as a function of the distance from the screen. 相似文献
175.
Ratnabali Biswas Kaushik Chowdhury Dharma P. Agrawal 《International Journal of Wireless Information Networks》2006,13(4):303-315
Wireless sensor network is an emerging technology that enables remote monitoring of large geographical regions. In this paper, we address the problem of distributing attributes over such a large-scale sensor network so that the cost of data retrieval is minimized. The proposed scheme is a data-centric storage scheme where the attributes are distributed over the network depending on the correlations between them. The problem addressed here is similar to the Allocation Problem of distributed databases. In this paper, we have defined the Allocation Problem in the context of sensor networks and have proposed a scheme for finding a good distribution of attributes to the sensor network. We also propose an architecture for query processing given such a distribution of attributes. We analytically determine the conditions under which the proposed architecture is beneficial and present simulation results to demonstrate the same. To the best of our knowledge, this is the first attempt to determine an allocation of attributes over a sensor network based on the correlations between attributes. 相似文献
176.
We report for the first time optical signal-to-noise penalties which lead to performance degradations in single-fiber long-reach optical access networks when compared to identical dual-fiber systems. A simplified architecture, with reduced optical amplifier count compared to previous work, for single-fiber operation of a symmetrical 10-Gb/s, 1024-way split, 110-km long-reach optical access network is presented and demonstrated. In addition, a possible solution to remove the optical signal-to-noise penalty is suggested 相似文献
177.
A multi-level attention framework for tracking and segmentation of humans and objects under complex occlusions is investigated,
featuring an effective probabilistic appearance-based technique for pixel reclassification during object grouping and splitting.
A novel ’spatial-depth affinity metric’ is introduced in the conventional likelihood function, utilising information of both
spatial locations of pixels and dynamic depth ordering of the component objects in grouping. Depth ordering estimation is
achieved through a combination of top-down and bottom-up approach. Experiments on some realworld difficult scenarios of low
quality and highly compressed videos demonstrate the very promising results achieved. 相似文献
178.
In this paper, a new approach for fault detection and isolation that is based on the possibilistic clustering algorithm is proposed. Fault detection and isolation (FDI) is shown here to be a pattern classification problem, which can be solved using clustering and classification techniques. A possibilistic clustering based approach is proposed here to address some of the shortcomings of the fuzzy c-means (FCM) algorithm. The probabilistic constraint imposed on the membership value in the FCM algorithm is relaxed in the possibilistic clustering algorithm. Because of this relaxation, the possibilistic approach is shown in this paper to give more consistent results in the context of the FDI tasks. The possibilistic clustering approach has also been used to detect novel fault scenarios, for which the data was not available while training. Fault signatures that change as a function of the fault intensities are represented as fault lines, which have been shown to be useful to classify faults that can manifest with different intensities. The proposed approach has been validated here through simulations involving a benchmark quadruple tank process and also through experimental case studies on the same setup. For large scale systems, it is proposed to use the possibilistic clustering based approach in the lower dimensional approximations generated by algorithms such as PCA. Towards this end, finally, we also demonstrate the key merits of the algorithm for plant wide monitoring study using a simulation of the benchmark Tennessee Eastman problem. 相似文献
179.
Pectic enzymes are widely used in the food industry for fruit juice extraction as well as in the clarification of cloudy juices. Our laboratory has been using pectic enzymes produced from a strain of Saccharomyces cerevisiae (ATCC 52712) in different applications including fruit juice extraction. The enzyme was produced in the laboratory by culturing the yeast in papaya juice supplemented with 1% pectin for 6 days. Known amounts of enzyme preparation (0–40 mg protein) were added to a measured weight of papaya mash for varying reaction periods (30–90 min) and the amount of free‐run juice obtained in each treatment compared with a control sample. Treatment of 200 g of papaya mash with different dosages of the pectic enzyme extract resulted in rapid increases in flow rate of free‐run juice. Mash treated with 32 mg of total protein extract with a 30‐min reaction time was the optimum for a maximum rate of juice flow (25 mL/min) when initial rates were measured. There was no significant difference (P > 0.05) between the red‐ and yellow‐fleshed varieties of the papaya used. When juice flow was monitored over 6 min, the treated samples gave a flow rate that was more than twice those of the untreated samples. This biotechnological approach could be adopted to enhance papaya‐juice production by local fruit juice processors when parameters for scale‐up processes are established. 相似文献
180.
S.J. Choi K. Djordjev Zhen Peng Qi Yang Sang Jun Choi P.D. Dapkus 《Photonics Technology Letters, IEEE》2004,16(10):2266-2268
All-buried InP-InGaAsP ring resonators laterally coupled to bus waveguides are demonstrated. The buried configurations offer a lower built-in refractive index step along the resonator periphery, which affords enhanced optical coupling coefficients between the waveguides and reduced scattering losses caused by the resonator sidewall imperfections. Very low optical intensity attenuations of 0.4 cm/sup -1/ and coupling-limited quality factors of greater than 10/sup 5/ are observed from 200-/spl mu/m-radii ring resonators. The measured spectral linewidth is as narrow as 0.0145 nm. 相似文献