全文获取类型
收费全文 | 454篇 |
免费 | 19篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 89篇 |
金属工艺 | 8篇 |
机械仪表 | 17篇 |
建筑科学 | 15篇 |
能源动力 | 39篇 |
轻工业 | 30篇 |
石油天然气 | 2篇 |
无线电 | 72篇 |
一般工业技术 | 82篇 |
冶金工业 | 25篇 |
自动化技术 | 90篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 9篇 |
2021年 | 13篇 |
2020年 | 23篇 |
2019年 | 21篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 20篇 |
2013年 | 40篇 |
2012年 | 13篇 |
2011年 | 22篇 |
2010年 | 18篇 |
2009年 | 21篇 |
2008年 | 18篇 |
2007年 | 8篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有473条查询结果,搜索用时 15 毫秒
81.
B Sriram Shastry 《Bulletin of Materials Science》1979,1(3-4):195-199
The remarkable remanence effects observed in spin glasses are discussed. Some theoretical approaches and results are reviewed.
Invited talk given at the Indian Academy of Sciences, Bangalore, Academy discussion meeting on phase transitions, June 21st,
1978. 相似文献
82.
Sriram K. Varshney P. Shanthikumar J. 《Selected Areas in Communications, IEEE Journal on》1983,1(6):1124-1132
Discrete-time analysis of two schemes for multiplexing voice and data is presented. In each scheme voice and data are multiplexed using the movable boundary frame allocation scheme. In the first scheme, speech activity detectors (SAD's) are not used, and hence, the variations in the voice traffic are only due to the on/off characteristics of voice. In the second scheme, SAD's are employed so that talker silences can he utilized for transmission of additional voice and/or data. In this scheme, the multiplexer performs digital speech interpolation as well as movable boundary frame allocation. The performance measures considered are probability of loss for voice calls, probability of speech clipping, speech packet rejection ratio, and the expected data message delay. In the case of the multiplexer with SAD, a tradeoff exists between data message delay and speech interpolation advantage. Some numerical examples are presented which illustrate the performance of the two multiplexers. 相似文献
83.
N Muthukumar D Kondziolka LD Lunsford JC Flickinger 《Canadian Metallurgical Quarterly》1998,140(4):315-20; discussion 320-1
Radical microsurgical resection is the procedure of choice for tentorial meningiomas. Despite advances in microsurgery, tentorial meningiomas continue to challenge surgeons and patients. To evaluate the response of tentorial meningiomas, we evaluated 41 patients who had Gamma knife stereotactic radiosurgery during a 9 year period. Patient age varied from 32 to 79 years. Headache, trigeminal neuralgia, or facial paraesthesia were the most common presenting symptoms. Sensory deficits in the distribution of the trigeminal nerve were the most common finding. Eighteen patients (44%) had undergone between 1 and 5 (mean, 1.9) resections prior to radiosurgery; 23 had tumors diagnosed by neuroimaging. The average tumor diameter in this series was 20 mm. The maximum tumor dose varied from 24 to 40 Gy (mean, 30.5 Gy), and the tumor margin dose varied from 12 to 20 Gy (mean, 15.3 Gy). During the average follow-up interval of 3 years (range, 1-8 years), 19 patients had clinical improvement, 20 remained stable, and 2 patients deteriorated. Follow-up imaging showed a reduction in tumor size in 18 patients, no further tumor growth in 22, and an increase in tumor size in one (overall tumor control rate of 98%). Stereotactic radiosurgery using the Gamma Knife was a safe and effective primary or adjuvant treatment for patients with tentorial meningiomas. 相似文献
84.
Muthukumar S. L. 《Cognition, Technology & Work》2005,7(1):46-50
Multimedia involves a combination of multiple modes such as text, graphics, audio and video to present information for learners. Multimedia-based learning has increasingly proliferated in educational circles, having been shaped by rapid technological advancements. In designing pedagogically sound multimedia systems a high premium needs to be placed on leveraging a judicious mix of various presentation modes to cater to users differing learning styles and needs. This will ensure that learning is optimised which is essentially learner-centric in nature in multimedia rich learning environments. Learner-centric in the sense that learners have control over the pace of their own learning and are empowered to take charge of their learning trajectories. In recent times, cognitive psychology has progressed in its empirical research development and many of the major findings in this field have been of use in the instructional design of multimedia educational resources. In this paper, we review some of these key principles and their implications in the development of multimedia contentware that is both aesthetically appealing and pedagogically engaging. 相似文献
85.
Dynamic response of flexible-link mechanism (structure) when subjected to external dynamic load is analyzed. The non-linear equations of motion are discretized using the finite element method (FEM) and Newmark time integration method combined with Newton-Raphson iterative technique is used for solution. From the dynamic response of the structure, the required kinematic characteristics are derived. Typical examples are worked out for illustration. 相似文献
86.
Kavitha S Venkata Krishna P Pounambal Muthukumar 《International Journal of Communication Systems》2020,33(9)
The performance of cyber physical system–based smart wireless networks depends on effective channel access by reducing the blocking, the dropping probability, and collisions. The aim of this proposed algorithm is to reduce the collisions in cyber physical system–based smart wireless networks. In this paper, multilevel medium access control in cyber physical system–based smart wireless networks is proposed. The optimal number of levels of gateways is determined using the concept of learning automata. Priority and time limit are assigned to every packet that is being transmitted. The proposed algorithm is evaluated and compared with two‐level medium access control in cyber physical system–based smart wireless networks, which is referred as priority with counter modified backoff (PCMB). The parameters used for evaluating the performance are throughput, delay, % of collisions, and number of packets dropped. The results project that the proposed algorithm accomplishes improved performance than PCMB. 相似文献
87.
Bharath Reddy Gudibandi Harish Adhithya Murugan Sriram Kumar Dhamodharan 《国际射频与微波计算机辅助工程杂志》2020,30(5)
In this article, miniaturization of the wire monopole antenna with the help of high refractive index (HRI) metamaterial is presented. For the first time, HRI medium is realized by using the array of single ring split ring resonator. By surrounding the wire monopole with the array of SR‐SRRs, the effective wavelength is squeezed in the vicinity of the near field dominance. By the loading of the monopole with such an HRI medium, the size of the antenna is reduced from 29.5 to 16 mm, without any deformation in the current distribution and radiation pattern corresponding to the fundamental resonance. The simulated and measured results are agreed to the same. 相似文献
88.
Harish Adhithya Murugan Gudibandi Bharath Reddy Sriram Kumar Dhamodharan 《国际射频与微波计算机辅助工程杂志》2020,30(10)
A coaxial‐fed tri‐band zeroth‐order resonance (ZOR) circularly polarized antenna with higher gains for all the excited ZORs is designed and analyzed in this paper. Epsilon negative transmission line (ENG TL) and pseudo‐open termination (P‐OT) unit cells with different series capacitances (CS and CS1 ) resonate shunt ZOR (fsh ) and two series ZORs (fse and fse1 ), respectively. Asymmetric unit cell concept is applied to ENG‐TL and P‐OT unit cells to create vertical and horizontal components, and the 90° phase shift is provided by the ZOR, resulting in circular polarization (CP). Left‐hand CP (LHCP) is achieved by creating two 90° right bends to the extended stubs in ENG TL and P‐OT unit cells. Higher gains for all the excited ZORs are achieved by shifting the shorting pins of ENG TL and P‐OT unit cells far away from the center position. After fabrication, the measured resonances occur at 4.64 GHz (fsh ), 4.04 GHz (fse ), and 3.86 GHz (fse1 ) with fractional bandwidths of 1.62%, 1.73%, and 1.6%, respectively. The measured LHCP peak gains are 4.05 dBic (fsh ), 3.85 dBic (fse ), and 3.94 dBic (fse1 ). The average axial ratio obtained is less than 3‐dB in the 10‐dB fractional bandwidth of the proposed antenna. 相似文献
89.
Rajivganthi C. Rihan F. A. Lakshmanan S. Muthukumar P. 《Neural computing & applications》2018,29(12):1309-1320
In this paper, the problem of finite-time stability for a class of fractional-order Cohen–Grossberg BAM neural networks with time delays is investigated. Using some inequality techniques, differential mean value theorem and contraction mapping principle, sufficient conditions are presented to ensure the finite-time stability of such fractional-order neural models. Finally, a numerical example and simulations are provided to demonstrate the effectiveness of the derived theoretical results.
相似文献90.
Steering the Craft: UI Elements and Visualizations for Supporting Progressive Visual Analytics 下载免费PDF全文
Progressive visual analytics (PVA) has emerged in recent years to manage the latency of data analysis systems. When analysis is performed progressively, rough estimates of the results are generated quickly and are then improved over time. Analysts can therefore monitor the progression of the results, steer the analysis algorithms, and make early decisions if the estimates provide a convincing picture. In this article, we describe interface design guidelines for helping users understand progressively updating results and make early decisions based on progressive estimates. To illustrate our ideas, we present a prototype PVA tool called Insights Feed for exploring Twitter data at scale. As validation, we investigate the tradeoffs of our tool when exploring a Twitter dataset in a user study. We report the usage patterns in making early decisions using the user interface, guiding computational methods, and exploring different subsets of the dataset, compared to sequential analysis without progression. 相似文献