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891.
892.
Peer-to-Peer (P2P) technology has become an attractive approach for enabling large-scale video streaming applications, but
the factor of users’ subjective preferences is not paid enough attention in such networks. As users have various demand on
video qualities, we can provide them with video streams at different resolutions without impairing their satisfaction. The
adaptive streaming rate technique is a promising method. However, in providing adaptive streaming rate services, P2P live
streaming design faces the following challenge: how to provide all users with uninterrupted video with their desired qualities
in case that their demand dynamically changes? To shed more light on this problem, we first derive a model and formulate the
problem as a resource demand vs supply problem. Then we present a framework to address the challenge via efficient bandwidth
allocation and group cooperation. Through comprehensive simulations, we evaluate the effectiveness of the proposed framework,
and conclude that it effectively helps existing solutions, such as Partial Participation Scheme (PPS), achieve better performance. 相似文献
893.
On filter theory of residuated lattices 总被引:3,自引:0,他引:3
The aim of this paper is to develop the filter theory of general residuated lattices. First, we extend some particular types of filters and fuzzy filters in BL-algebras and MTL-algebras naturally to general residuated lattices, and further enumerate some relative results obtained in BL-algebras or MTL-algebras, which still hold in general residuated lattices. Next, we introduce the concepts of regular filters and fuzzy regular filters to general residuated lattices, which are two new types of filters and fuzzy filters, and derive some of their characterizations. Finally, we discuss the relations between (fuzzy) regular filters and several other special (fuzzy) filters, and also characterize some special classes of residuated lattices by filters or fuzzy filters. 相似文献
894.
Locality preserving projection (LPP) is a manifold learning method widely used in pattern recognition and computer vision. The face recognition application of LPP is known to suffer from a number of problems including the small sample size (SSS) problem, the fact that it might produce statistically identical transform results for neighboring samples, and that its classification performance seems to be heavily influenced by its parameters. In this paper, we propose three novel solution schemes for LPP. Experimental results also show that the proposed LPP solution scheme is able to classify much more accurately than conventional LPP and to obtain a classification performance that is only little influenced by the definition of neighbor samples. 相似文献
895.
Bimodal biometrics has been found to outperform single biometrics and are usually implemented using the matching score level or decision level fusion, though this fusion will enable less information of bimodal biometric traits to be exploited for personal authentication than fusion at the feature level. This paper proposes matrix-based complex PCA (MCPCA), a feature level fusion method for bimodal biometrics that uses a complex matrix to denote two biometric traits from one subject. The method respectively takes the two images from two biometric traits of a subject as the real part and imaginary part of a complex matrix. MCPCA applies a novel and mathematically tractable algorithm for extracting features directly from complex matrices. We also show that MCPCA has a sound theoretical foundation and the previous matrix-based PCA technique, two-dimensional PCA (2DPCA), is only one special form of the proposed method. On the other hand, the features extracted by the developed method may have a large number of data items (each real number in the obtained features is called one data item). In order to obtain features with a small number of data items, we have devised a two-step feature extraction scheme. Our experiments show that the proposed two-step feature extraction scheme can achieve a higher classification accuracy than the 2DPCA and PCA techniques. 相似文献
896.
New GOES imager algorithms for cloud and active fire detection and fire radiative power assessment across North, South and Central America 总被引:1,自引:0,他引:1
Vegetation fires are a key global terrestrial disturbance factor and a major source of atmospheric trace gases and aerosols. Therefore, many earth-system science and operational monitoring applications require access to repetitive, frequent and well-characterized information on fire emissions source strengths. Geostationary imagers offer important temporal advantages when studying rapidly changing phenomena such as vegetation fires. Here we present a new algorithm for detecting and characterising active fires burning within the imager footprints of the Geostationary Operational Environmental Satellites (GOES), including consideration of cloud-cover and calculation of fire radiative power (FRP), a metric shown to be strongly related to fuel consumption and smoke emission rates. The approach is based on a set of algorithms now delivering near real time (NRT) operational FRP products from the Meteosat Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) imager (available from http://landsaf.meteo.pt/), and the GOES processing chain presented here is designed to deliver a compatible fire product to complete geostationary coverage of the Western hemisphere. Results from the two GOES imagers are intercompared, and are independently verified against the well regarded MODIS cloud mask and active fire products. We find that the detection of cloud and active fires from GOES matches that of MODIS very well for fire pixels having FRP > 30 MW, when the GOES omission error falls to less than 10%. The FRP of fire clusters detected near simultaneously by both GOES and MODIS have a bias of only 22 MW, and a similar bias is found when comparing near-simultaneous GOES East and GOES West FRP observations. However, many fire pixels having FRP < 30 MW remain undetected by GOES, probably unavoidably since it has a much coarser spatial resolution than MODIS. Adjustment using data from the less frequent but more accurate views obtained from high spatial resolution polar orbiting imagers could be used to bias correct regional FRP totals. Temporal integration of the GOES FRP record indicates that during the summer months, biomass burning combusts thousands of millions of tonnes of fuel daily across the Americas. Comparison of these results to those of the Global Fire Emissions Database (GFEDv2) indicate strong linear relationships (r² > 0.9), suggesting that the timely FRP data available from a GOES real-time data feed is likely to be a suitable fire emissions source strength term for inclusion in schemes aiming to forecast the concentrations of atmospheric constituents affected by biomass burning. 相似文献
897.
898.
根据医学领城应用计算机技术的现状,对医学实验、辅助诊断、图像处理、医院综合管理等方面的应用做简要概述,并举例说明计算机在医疗领域的具体应用. 相似文献
899.
设计了护栏管显示与控制系统,给出了它们的硬件电路图。结合驱动芯片P9816的通信协议,编写了相应程序来控制护栏管的显示。系统采用控制器读取SD卡中的数据并进行处理,将处理后的数据送入护栏管,护栏管即可显示丰富多彩的内容。 相似文献
900.
针对现有家居控制系统功耗大和成本高等缺陷,设计了一种基于CC430F6135单片机的低功耗智能家居控制系统.本系统具有功耗低、控制可靠性高、人性化等特点.介绍了CC430F6135芯片内部集成的RF无线模块特点和家居控制系统的结构原理,给出了硬件设计框图和软件流程,详细分析了中央控制模块、RF无线收发功能模块和触摸屏控... 相似文献