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991.
Tadao Aizawa 《Electrical Engineering in Japan》2009,166(2):32-38
Most general‐purpose analyzers for harmonic analysis on distribution lines are designed to sample the data of one or two power supply periods. In other words, these analyzers process waveforms and display the results based on the assumption that the analyzed waveforms contain no noninteger components, such as subharmonics and interharmonics. When waveforms containing noninteger components are analyzed with these general‐purpose analyzers, the results often indicate components that are not actually present. This paper proposes a technique of waveform judgment and explains its method of application. The technique allows noninteger components to be recognized in analyzed waveforms from the properties of Lissajous figures, and clarifies the types of components and the time windows necessary for appropriate analysis. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(2): 32– 38, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20536 相似文献
992.
Three experiments used the "list-before-the-last" free recall paradigm (Shiffrin, 1970) to investigate retrieval for context and the manner in which context changes. This paradigm manipulates target and intervening list lengths to measure the interference from each list, providing a measure of list isolation. Correct target list recall was only affected by the target list length when participants engaged in recall between the lists, whereas there were effects of both list lengths with other activities. This suggests that the act of recalling drives context change, thus isolating the target list from interference. Correspondingly, incorrect recall of intervening list items was affected only by the length of the intervening list when recall occurred between the lists, but was otherwise affected by both list lengths. Concurrent with these changes in context similarity, there were apparent changes in context retrieval, as indicated by the overall levels of target retrieval versus intervening recall. A multinomial model of sampling and recovery was implemented to assess the adequacy of this account and to quantify context similarity and context retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
使用“脉冲信号流统计理论”建立了由群体电磁干扰源产生的电磁干扰脉冲流的一维概率密度函数(pdf)统计模型具有普遍性特点。分析了建立了杂乱脉冲干扰流和来自有限,无限数量干扰源干扰流的统计模型。 相似文献
994.
995.
Selecting a threshold from the gradient histogram, a histogram of gradient magnitudes, of an image plays a crucial role in a gradient based edge detection system. This paper presents a methodology to determine the threshold from a gradient histogram generated using any kind of linear gradient operator on an image. We consider the image as a random process with dependent samples, model the gradient histogram using theories of random process and random input to a system, and determine a region of interest in the gradient histogram using certain properties of a probability density function. Standard histogram thresholding techniques are then used within the region of interest to get the threshold value. To obtain the edges, this threshold value is then used as the upper threshold of the hysteresis thresholding technique that follows the non-maximum suppression operation applied on the gradient magnitude image. The proposed methodology of determining a threshold in a gradient histogram is deduced through rigorous analysis and hence it helps in achieving consistently appreciable edge detection performance. Experimental results using different real-life and benchmark images are shown to demonstrate the effectiveness of the proposed technique. 相似文献
996.
Jui Teng Wang 《AEUE-International Journal of Electronics and Communications》2010,64(11):1090-1093
The time slotted system with rate regulation, which adapts the transmission rate to the interference for each time slot, is proposed to enhance the throughput while meeting the SINR requirement for cochannel interference limited wireless ad hoc networks. We show that the throughput of the rate regulated TDMA system is larger than that of the rate regulated TDMA/CDMA system. Furthermore, we also propose a scheduling algorithm to maximize the total throughput of the rate regulated TDMA system. 相似文献
997.
提出了一种新的K空间权重导航技术(DKWN),该技术有利于缩短磁共振冠脉成像扫描时间同时获得好的图像质量.并将该导航技术应用到25位健康志愿者.经过实验分析,相比于常规固定窗导航技术而言,DKWN可以使导航效率提高30%(P<0.05),同时平均扫描时间由2.12 min缩短至1.64 min(P<0.05),并且图像质量相当.冠脉的直径和长度没有显著差异. 相似文献
998.
E. Dhooge and R. J. Hartsuiker (2010) reported experiments showing that picture naming takes longer with low- than high-frequency distractor words, replicating M. Miozzo and A. Caramazza (2003). In addition, they showed that this distractor-frequency effect disappears when distractors are masked or preexposed. These findings were taken to refute models like WEAVER++ (A. Roelofs, 2003) in which words are selected by competition. However, Dhooge and Hartsuiker do not take into account that according to this model, picture-word interference taps not only into word production but also into attentional processes. Here, the authors indicate that WEAVER++ contains an attentional mechanism that accounts for the distractor-frequency effect (A. Roelofs, 2005). Moreover, the authors demonstrate that the model accounts for the influence of masking and preexposure, and does so in a simpler way than the response exclusion through self-monitoring account advanced by Dhooge and Hartsuiker. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
999.
Fang Liang Zhao Zhengyu Wang Feng Su Fanfan 《Frontiers of Electrical and Electronic Engineering in China》2007,2(4):415-419
The real-time information of the distant ionosphere can be acquired by using the Wuhan ionospheric oblique backscattering
sounding system (WIOBSS), which adopts a discontinuous wave mechanism. After the characteristics of the ionospheric echo Doppler
spectra were analyzed, the signal preprocessing was developed in this paper, which aimed at improving the Doppler spectra.
The results indicate that the preprocessing not only makes the system acquire a higher ability of target detection but also
suppresses the radio frequency interference by 6–7 dB.
__________
Translated from Journal of Wuhan University (Natural Science), 2006, 52(1): 114–118 [译自: 武汉大学学报(理学版)] 相似文献
1000.
Carter Frances A.; McIntosh Virginia V. W.; Joyce Peter R.; Bulik Cynthia M. 《Canadian Metallurgical Quarterly》2008,117(4):936
The authors attempted to replicate previous findings that weight suppression is a significant predictor of treatment completion and treatment outcome (M. L. Butryn, M. R. Lowe, D. L. Safer, & W. S. Agras, 2006) and weight gain over treatment (M. R. Lowe, W. Davis, D. Lucks, R. A. Annunziato, & M. L. Butryn, 2006) among women with bulimic disorders. The authors also examined 2 alternative measures of weight variability. Participants were 132 women with bulimia nervosa treated with cognitive-behavioral therapy. Participants who dropped out of treatment did not have significantly higher levels of weight suppression than did treatment completers. Among those who completed treatment, weight suppression did not significantly predict binge eating and purging at post-treatment. Weight suppression did significantly predict weight change and, in particular, weight gain (≥5 kg) over treatment. Alternative measures of weight variability did not significantly predict treatment completion or treatment outcome, but 1 measure significantly predicted weight gain over treatment. In conclusion, the authors failed to replicate the previous finding that weight suppression predicts treatment compliance and treatment outcome, but they did replicate the finding that weight suppression predicts weight gain over treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献