全文获取类型
收费全文 | 584篇 |
免费 | 20篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 54篇 |
综合类 | 3篇 |
化学工业 | 85篇 |
金属工艺 | 9篇 |
机械仪表 | 20篇 |
建筑科学 | 27篇 |
能源动力 | 5篇 |
轻工业 | 15篇 |
无线电 | 153篇 |
一般工业技术 | 83篇 |
冶金工业 | 72篇 |
原子能技术 | 4篇 |
自动化技术 | 76篇 |
出版年
2023年 | 6篇 |
2022年 | 13篇 |
2021年 | 7篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 14篇 |
2015年 | 5篇 |
2014年 | 7篇 |
2013年 | 36篇 |
2012年 | 22篇 |
2011年 | 21篇 |
2010年 | 19篇 |
2009年 | 25篇 |
2008年 | 32篇 |
2007年 | 38篇 |
2006年 | 31篇 |
2005年 | 21篇 |
2004年 | 23篇 |
2003年 | 27篇 |
2002年 | 23篇 |
2001年 | 20篇 |
2000年 | 24篇 |
1999年 | 21篇 |
1998年 | 38篇 |
1997年 | 16篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 5篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有606条查询结果,搜索用时 0 毫秒
11.
Montesinos CA Tse ZT Chan YJ Elhawary H Rea M Hamed A Young I Lamperth M 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2012,226(1):49-54
The static magnetic field of a magnetic resonance imaging scanner can be distorted by the presence of materials, perturbing the spatial encoding process in magnetic resonance imaging and often resulting in image artifacts. The relationship between the image artifact size and magnetic susceptibility of the material specimen is of interest to engineers for the design of devices that are to be compatible with the imaging volume of the scanner. In this study, a finite-element method was used to simulate the distorted magnetic field of samples with different susceptibilities. With the knowledge of the external- and self- magnetic field interactions, a Lorentz correction was applied to compute the magnetic field deviation. The simulated results were then validated by the corresponding experimental magnetic resonance images. 相似文献
12.
Tin oxide thin films have been deposited by a custom-designed inductively coupled plasma chemical vapor deposition (ICP-CVD)
system in order to explore its application as an alternative approach for thin film gas sensor preparation. The as-deposited
SnO2 films were of polycrystalline structure with nano-size grains of 12 nm. The SnO2 films exhibited a maximum sensitivity of 43 to 1000 ppm H2 at an optimum operating temperature of 350∘C. The response time of the SnO2 films was 12 s and full recovery was achievable. 相似文献
13.
Etkin R.H. Tse D.N.C. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(4):1576-1608
Consider a multiple-input multiple-output (MIMO) fading channel in which the fading process varies slowly over time. Assuming that neither the transmitter nor the receiver have knowledge of the fading process, do multiple transmit and receive antennas provide significant capacity improvements at high signal-to-noise ratio (SNR)? For regular fading processes, recent results show that capacity ultimately grows doubly logarithmically with the SNR independently of the number of transmit and receive antennas used. We show that for the Gauss-Markov fading process in all regimes of practical interest the use of multiple antennas provides large capacity improvements. Nonregular fading processes show completely different high-SNR behaviors due to the perfect predictability of the process from noiseless observations. We analyze the capacity of MIMO channels with nonregular fading by presenting a lower bound, which we specialize to the case of band-limited slowly varying fading processes to show that the use of multiple antennas is still highly beneficial. In both cases, regular and nonregular fading, this capacity improvement can be seen as the benefit of having multiple spatial degrees of freedom. For the Gauss-Markov fading model and all regimes of practical interest, we present a communication scheme that achieves the full number of degrees of freedom of the channel with tractable complexity. Our results for underspread Gauss-Markov and band-limited nonregular fading channels suggest that multiple antennas are useful at high SNR. 相似文献
14.
Chen CW Lin WC Liao LS Lin ZH Chiang HP Leung PT Sijercic E Tse WS 《Applied optics》2007,46(22):5347-5351
The possibility of constructing an optical sensor for temperature monitoring based on the Goos-H?nchen (GH) effect is explored using a theoretical model. This model considers the lateral shift of the incident beam upon reflection from a metal-dielectric interface, with the shift becoming a function of temperature due mainly to the temperature dependence of the optical properties of the metal. It is found that such a sensor can be most effective by using long wavelength p-polarized incident light at almost grazing incidence onto the metal, where significant variation of negative GH shifts can be observed as a function of the temperature. 相似文献
15.
16.
Chung H. Hui S.Y.R. Tse K.K. 《Electromagnetic Compatibility, IEEE Transactions on》1998,40(3):282-287
Measurements of conducted and radiated electromagnetic interference (EMI) emission from hard-switched and soft-switched buck, boost, and flyback converters of similar power ratings are presented. Results indicate that EMI emission can be substantially reduced by using a soft-switching technique in power converters. Thus, the soft-switching technique provides a practical and useful solution to reduce EMI emission from switched-mode power circuits. A comparison of EMI emission on the three classes of converters is also included. The flyback converter is found to be the least EMC friendly among the converters tested 相似文献
17.
The paper targets to devise a genuine Knowledge Management (KM) performance measurement model in a stochastic setting based on Data Envelopment Analysis (DEA), Monte Carlo simulation and Genetic Algorithm (GA). The proposed model evaluates KM using a set of proxy measures correlated with the major KM processes. Data Collection Budget Allocation (DCBA) that maximizes the model accuracy is determined using GA. Additional data are generated and analyzed using a Monte-Carlo-enhanced DEA model to obtain the overall KM efficiency and KM processes’ efficiency scores. An application of the model has been carried out to evaluate KM performance in higher educational institutions. It is found that with GA, the accuracy of the model has been greatly improved. Lastly, comparing with a conventional deterministic DEA model, the results from the proposed model would be more useful for managers to determine future strategies to improve their KM. 相似文献
18.
M. Berkan Sesen Michael D. Peake Rene Banares-Alcantara Donald Tse Timor Kadir Roz Stanley Fergus Gleeson Michael Brady 《Journal of the Royal Society Interface》2014,11(98)
Multidisciplinary team (MDT) meetings are becoming the model of care for cancer patients worldwide. While MDTs have improved the quality of cancer care, the meetings impose substantial time pressure on the members, who generally attend several such MDTs. We describe Lung Cancer Assistant (LCA), a clinical decision support (CDS) prototype designed to assist the experts in the treatment selection decisions in the lung cancer MDTs. A novel feature of LCA is its ability to provide rule-based and probabilistic decision support within a single platform. The guideline-based CDS is based on clinical guideline rules, while the probabilistic CDS is based on a Bayesian network trained on the English Lung Cancer Audit Database (LUCADA). We assess rule-based and probabilistic recommendations based on their concordances with the treatments recorded in LUCADA. Our results reveal that the guideline rule-based recommendations perform well in simulating the recorded treatments with exact and partial concordance rates of 0.57 and 0.79, respectively. On the other hand, the exact and partial concordance rates achieved with probabilistic results are relatively poorer with 0.27 and 0.76. However, probabilistic decision support fulfils a complementary role in providing accurate survival estimations. Compared to recorded treatments, both CDS approaches promote higher resection rates and multimodality treatments. 相似文献
19.
Kathryn Rounding Kimberly Tee Xiaomin Wu Cheng Guo Edward Tse 《Personal and Ubiquitous Computing》2013,17(8):1663-1666
Children are very different from adults—they have developing motor skills, limited reach, short attention spans, limited exposure to traditional user interfaces and social protocols. How do we evaluate user interfaces for children? In this paper, we present four evaluative techniques that we have successfully used with children. 相似文献
20.
Yung‐Tse Hung 《The International journal of environmental studies》2013,70(3-4):261-270
The batch shaking adsorption study was conducted to determine the potential of fly and volcanic ashes in removing organic pollutants from oxidation pond effluents. Factors affecting organic pollutant removals, such as concentrations and sizes of fly and volcanic ashes, initial pond effluent organic concentrations, washed and unwashed conditions of fly and volcanic ashes, were investigated. The TOC (total organic carbon) removal efficiency varied from 30 to 58 percent. The organic removal efficiency increased with increasing ash concentrations, with decreasing initial pond effluent organic concentrations and with decreasing sizes of ashes. 相似文献