全文获取类型
收费全文 | 366篇 |
免费 | 17篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 13篇 |
化学工业 | 95篇 |
金属工艺 | 6篇 |
机械仪表 | 6篇 |
建筑科学 | 5篇 |
矿业工程 | 3篇 |
能源动力 | 14篇 |
轻工业 | 22篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 84篇 |
一般工业技术 | 64篇 |
冶金工业 | 26篇 |
原子能技术 | 1篇 |
自动化技术 | 43篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 19篇 |
2020年 | 8篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2017年 | 16篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 22篇 |
2012年 | 15篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 26篇 |
2008年 | 11篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有385条查询结果,搜索用时 31 毫秒
21.
22.
23.
Arjun DeySamit Kumar Nandi Biswanath Kundu Chandrasekhar KumarPrasenjit Mukherjee Subhasis RoyAnoop Kumar Mukhopadhyay Mithlesh Kumar SinhaDebabrata Basu 《Ceramics International》2011,37(4):1377-1391
Here we report a comparative study of the healing kinetics of surgically created artificial defects in the tibia of New Zealand white rabbits. Comparison of the healing kinetics was made for uncoated conventional SS316L intramedullary pins, and the same pins with microplasma sprayed (MIPS) pure hydroxyapatite (HAp) and beta-tri calcium phosphate (β-TCP) coatings. After thorough material characterizations including XRD, FTIR, SEM, etc., MIPS coated pins were implanted to such animals. Serum biochemistry, radiology and fluorochrome labelling were used to evaluate the comparative healing kinetics of these implants in vivo. In comparison to those of the uncoated pins, the pins coated with both MIPS HAp and β-TCP showed significant increment of alkaline phosphatase up to 15th postoperative day, insignificant changes in serum phosphorus and calcium with uneventful healing of bone defect. There was development of Havarsian canals and well-defined peripherally placed osteoblasts along with evidence of angiogenesis and comparatively more new bone formation in the defect site. On a comparative scale, the performance of the β-TCP coated intramedullary pins was much better than that of the pure HAp coated pins than the uncoated intramedullary pins. 相似文献
24.
Ytterbium-doped sodium phospho-tellurite glasses are made with different P2O5:TeO2 ratio, and Yb3+ concentrations. Physical properties of the new Yb hosts are favorable for laser applications. The glasses show high absorption and emission cross sections and higher lifetime of Yb3+:2F5/2rarr2F7/2 transition. The emission cross sections are calculated using two different methods and compared. The laser parameters of these Yb3+ -doped glasses are better than many reported glasses and crystals making them potential to fabricate high power laser and broadband optical amplifier in the wavelength region around ~1 mum 相似文献
25.
A simple digitally programmable oscillator (DPO) based on a two-integrator loop is described. A simple experimental model for signal processing/generation (e.g., frequency shift keying, amplitude shift keying, phase shift keying/binary phase shift keying) useful in digital communication has been derived from the DPO by employing a microprocessor. The setup can be conveniently utilized for demonstration and experimentation in the communications laboratory. Some test results are included 相似文献
26.
Arup Kumar Nandi Frank Klawonn 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2007,11(5):467-478
Regression refers to the problem of approximating measured data that are assumed to be produced by an underlying, possibly
noisy function. However, in real applications the assumption that the data represent samples from one function is sometimes
wrong. For instance, in process control different strategies might be used to achieve the same goal. Any regression model,
trying to fit such data as good as possible, must fail, since it can only find an intermediate compromise between the different
strategies by which the data were produced. To tackle this problem, an approach is proposed here to detect ambiguities in
regression problems by selecting a subset of data from the total data set using TSK models, which work in parallel by sharing
the data with each other in every step. The proposed approach is verified with artificial data, and finally utilised to real
data of grinding, a manufacturing process used to generate smooth surfaces on work pieces. 相似文献
27.
AbstractThe visual perception of eyewitness plays a vital role in criminal identification scenario. It helps law enforcement authorities in searching particular criminal from their previous record. It has been reported that searching a criminal record manually requires too much time to get the accurate result. We have proposed a query-based approach which minimises the computational cost along with the reduction of search space. A symbolic database has been created to perform a stringent analysis on 150 public (Bollywood celebrities and Indian cricketers) and 90 local faces (our data-set). An expert knowledge has been captured to encapsulate every criminal’s anatomical and facial attributes in the form of symbolic representation. A fast query-based searching strategy has been implemented using dynamic decision tree data structure which allows four levels of decomposition to fetch respective criminal records. Two types of case studies - viewed and forensic sketches have been considered to evaluate the strength of our proposed approach. We have derived 1200 views of the entire population by taking into consideration 80 participants as eyewitness. The system demonstrates an accuracy level of 98.6% for test case I and 97.8% for test case II. It has also been reported that experimental results reduce the search space up to 30 most relevant records. 相似文献
28.
A new floating negative admittance convenor (FNAC) network using the second-generation current conveyor (CCII) active devices has been proposed. The novelties of the scheme are no component matching requirements, use of only the nominal termination admittance under ideal device conditions, and practically active-insensitive network characteristics. Even with nonideal but matched devices, no extra matching component is required for a true FNAC realisation. However, with nonideal and nonidentical devices, insertion of a single compensating admittance yields a precise bilateral FNAC. 相似文献
29.
30.
Through a series of simulations with one dimensional real digital signals, the effects of various degrees of phase degradation for different lengths of sequences and for different choices in the set of sampling frequencies on the quality (as measured by normalised mean-square-error-NMSE) of signals reconstructed from noisy Fourier transform (FT) phases is established.<> 相似文献