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941.
942.
在我国西南地区机场建设过程中,由于山地凹凸,要大量采用爆破开挖进行土石方工程的作业,产生的爆破费用较高,且作业具有一定的危险性。介绍了中深孔爆破方法,其具有爆破成本低、单次爆破量大、施工环境较好、作业安全等优点,可在类似工程中推广使用。 相似文献
943.
Zhao Ren Kun Qian Zixing Zhang Vedhas Pandit Alice Baird Bj?rn Schuller 《IEEE/CAA Journal of Automatica Sinica》2018,5(3):662-669
Spectrogram representations of acoustic scenes have achieved competitive performance for acoustic scene classification. Yet, the spectrogram alone does not take into account a substantial amount of time-frequency information. In this study, we present an approach for exploring the benefits of deep scalogram representations, extracted in segments from an audio stream. The approach presented firstly transforms the segmented acoustic scenes into bump and morse scalograms, as well as spectrograms; secondly, the spectrograms or scalograms are sent into pre-trained convolutional neural networks; thirdly, the features extracted from a subsequent fully connected layer are fed into (bidirectional) gated recurrent neural networks, which are followed by a single highway layer and a softmax layer; finally, predictions from these three systems are fused by a margin sampling value strategy. We then evaluate the proposed approach using the acoustic scene classification data set of 2017 IEEE AASP Challenge on Detection and Classification of Acoustic Scenes and Events (DCASE). On the evaluation set, an accuracy of 64.0% from bidirectional gated recurrent neural networks is obtained when fusing the spectrogram and the bump scalogram, which is an improvement on the 61.0% baseline result provided by the DCASE 2017 organisers. This result shows that extracted bump scalograms are capable of improving the classification accuracy, when fusing with a spectrogram-based system. 相似文献
944.
A recent Quantum Private Set Intersection (QPSI) scheme is crypt-analyzed. The original claimed communication overhead is shown to be not accurate. And the original security definition is passive and not fair. To ensure fairness, a passive third party is introduced. It is also shown that unconditional fairness of QPSI protocol is impossible. Since otherwise, it would violate a well-known impossible quantum cryptography result. 相似文献
945.
We present particle counting ultrahigh-resolution optical Doppler tomography (pc-μODT) that enables accurate imaging of red blood cell velocities (ν(RBC)) of cerebrovascular networks by detecting the Doppler phase transients induced by the passage of a RBC through a capillary. We apply pc-μODT to image the response of capillary ν(RBC) to mild hypercapnia in mouse cortex. The results show that ν(RBC) in normocapnia (ν(N)?=?0.72?±?0.15?mm/s) increased 36.1%?±?5.3% (ν(H)?=?0.98?±?0.29?mm/s) in response to hypercapnia. Due to uncorrected angle effect and low hematocrit (e.g., ~10%), ν(RBC) directly measured by μODT were markedly underestimated (ν(N) ≈ 0.27?±?0.03?mm/s, ν(H) ≈ 0.37±?0.05?mm/s). Nevertheless, the measured ν(RBC) increase (35.3%) matched that (36.1%?±?5.3%) by pc-μODT. 相似文献
946.
We present and investigate techniques for optimizing particle dispersions in all kinds of Reynolds number flows. In particular,
we show the range of application, power and efficiency of space mapping approaches that are based on a hierarchy of models
ranging from a complex (fine, accurate, costly) to simple (coarse, rough, cheap) model. Space mapping turns out to be a reasonable
approximation to optimal control and a competitive alternative to instantaneous control regarding speed and memory demands
when dealing with complex, non-stationary problems. Moreover it allows the easy and efficient treatment of stochastic design
problems. To control random particle dynamics in a turbulent flow, we suggest a Monte-Carlo aggressive space mapping algorithm
which yields very convincing numerical results. 相似文献
947.
948.
Jorge René Nuricumbo Haider Ali Zoltán-Csaba Márton Marcin Grzegorzek 《Multimedia Tools and Applications》2016,75(12):6829-6847
Nowadays object recognition is a fundamental capability for an autonomous robot in interaction with the physical world. Taking advantage of new sensing technologies providing RGB-D data, the object recognition capabilities increase dramatically. Object recognition has been well studied, however, known object classifiers usually feature poor generality and, therefore, limited adaptivity to different application domains. Although some domain adaptation approaches have been presented for RGB data, little work has been done on understanding the effects of applying object classification algorithms using RGB-D for different domains. Addressing this problem, we propose and comprehensively investigate an approach for object recognition in RGB-D data that uses adaptive Support Vector Machines (aSVM) and, in this way, achieves an impressive robustness in cross-domain adaptivity. For evaluation, two datasets from different application domains were used. Moreover, a study of state-of-the-art RGB-D feature extraction techniques and object classification methods was performed to identify which combinations (object representation - classification algorithm) remain less affected in terms of performance while switching between different application domains. 相似文献
949.
We perform a comprehensive study of the ionization of hydrogen atom by a few-cycle laser pulse with a fixed carrier-envelop in phase space through calculating the Wigner functions. The results show that the electrons always locate around the nucleus before the laser electric field force reaches a certain intensity. While as the force of the laser electric field increases, the electrons are gradually deviated away from the nucleus. The ionized electrons are driven back to the core region and make a wiggling motion because of the variation of the laser electric field force with time. Moreover Wigner functions enable us to clearly show the classical and quantum behaviours during ionization process are presented in phase space, and explicitly attribute the arc fringes to the interference effect between the electronic wavepackets born at different ionization times. 相似文献
950.