全文获取类型
收费全文 | 2423篇 |
免费 | 139篇 |
国内免费 | 19篇 |
专业分类
电工技术 | 50篇 |
综合类 | 9篇 |
化学工业 | 579篇 |
金属工艺 | 64篇 |
机械仪表 | 79篇 |
建筑科学 | 92篇 |
矿业工程 | 6篇 |
能源动力 | 192篇 |
轻工业 | 257篇 |
水利工程 | 21篇 |
石油天然气 | 24篇 |
无线电 | 244篇 |
一般工业技术 | 411篇 |
冶金工业 | 178篇 |
原子能技术 | 17篇 |
自动化技术 | 358篇 |
出版年
2024年 | 9篇 |
2023年 | 46篇 |
2022年 | 98篇 |
2021年 | 120篇 |
2020年 | 113篇 |
2019年 | 109篇 |
2018年 | 127篇 |
2017年 | 126篇 |
2016年 | 110篇 |
2015年 | 79篇 |
2014年 | 118篇 |
2013年 | 242篇 |
2012年 | 154篇 |
2011年 | 183篇 |
2010年 | 124篇 |
2009年 | 120篇 |
2008年 | 104篇 |
2007年 | 90篇 |
2006年 | 51篇 |
2005年 | 34篇 |
2004年 | 32篇 |
2003年 | 35篇 |
2002年 | 28篇 |
2001年 | 30篇 |
2000年 | 23篇 |
1999年 | 21篇 |
1998年 | 40篇 |
1997年 | 34篇 |
1996年 | 28篇 |
1995年 | 24篇 |
1994年 | 18篇 |
1993年 | 6篇 |
1992年 | 15篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有2581条查询结果,搜索用时 15 毫秒
1.
Durmuş Burhanettin Temurtaş Hasan Özyön Serdar 《Neural computing & applications》2020,32(22):17097-17113
Neural Computing and Applications - This study presents the design of a tenth-order multiple feedback Chebyshev low-pass filter (MF-C-LPF). Component selection and gain calculation of filters are... 相似文献
2.
3.
4.
5.
Huseyin Avci Esra Akkulak Hazal Gergeroglu Hamed Ghorbanpoor Onur Uysal Ayla Eker Sariboyaci Bahar Demir Merve Nur Soykan Suat Pat Reza Mohammadigharehbagh Ceren Özel Ahmet Cabuk Fatma Doğan Güzel 《应用聚合物科学杂志》2020,137(26):49184
Among the thermoplastic elastomers that play important roles in the polymer industry due to their superior properties, styrene-based species and polyurethane block copolymers are of great interest. Poly(styrene-ethylene-butadiene-styrene) (SEBS) as a triblock copolymer seems to have the potential to meet many demands in different applications due to various industrial requirements where durability, biocompatibility, breaking elongation, and interfacial adhesion are important. In this study, the SEBS triblock copolymer was functionalized with natural (Satureja hortensis, SH) and synthetic (nanopowder, TiO2) agents to obtain composite nanofibers by electrospinning and electrospraying methods for use in biomedical and water filtration applications. The results were compared with thermoplastic polyurethane (TPU) composite nanofibers, which are commonly used in these fields. Here, functionalized SEBS nanofibers exhibited antibacterial effect while at the same time improving cell viability. In addition, because of successful water filtration by using the SEBS composite nanofibers, the material may have a good potential to be used comparably to TPU for the application. 相似文献
6.
7.
OVSF codes are used as channelization codes in WCDMA. Due to code blocking property of OVSF codes, the bandwidth available in the system is severely limited. Code reassignments mitigate the impact of the blocking property at the expense of causing delays and decreasing the throughput of the system. Nonblocking OVSF (NOVSF) codes have been proposed to alleviate the adverse effect of code reassignments. This paper presents a code assignment algorithm for NOVSF codes, which does not require any code reassignments. Simulation results show that NOVSF codes achieve better throughput than OVSF codes, even though code reassignments are allowed in the assignments of OVSF codes. 相似文献
8.
Hasan M.K. Hossain N.M. Naylor P.A. 《Vision, Image and Signal Processing, IEE Proceedings -》2005,152(5):520-526
A novel method for parameter estimation of minimum-phase autoregressive moving average (ARMA) systems in noise is presented. The ARMA parameters are estimated using a damped sinusoidal model representation of the autocorrelation function of the noise-free ARMA signal. The AR parameters are obtained directly from the estimates of the damped sinusoidal model parameters with guaranteed stability. The MA parameters are estimated using a correlation matching technique. Simulation results show that the proposed method can estimate the ARMA parameters with better accuracy as compared to other reported methods, in particular for low SNRs. 相似文献
9.
Murat Ozdemir & Hasan Sadikoglu 《International Journal of Food Science & Technology》1998,33(5):439-444
The effects of addition of κ-carrageenan to solutions containing 40% (w/w) sugar substitute on the rheological properties of these systems were investigated at 25 °C using a rotational viscometer at rotational speeds of 6, 12, 30, and 60 rev min−1 . The flow behaviour of the solutions was adequately described by the power law model with or without yield stress. The consistency index ( K ) and the flow behaviour index ( n ) were determined from shear stress vs. shear rate data. The flow parameters of the solutions depended on the carrageenan concentration. The apparent viscosities of the systems decreased with increasing shear rate, indicating pseudoplastic behaviour. The final carrageenan concentration was found to be an effective factor controlling the degree of sliminess of the model food systems studied. 相似文献
10.
The interaction of different metal oxides such as Co3O4, NiO, Al2O3, Cr2O3, Fe2O3 and SiO2 with Na2SO4 at a temperature of 1100 and 1200 K in flowing oxygen has been studied. The thermogravimetric studies for each system were
carried out as a function of Na2SO4 in the mixture. The presence of different constituents in the reaction products were identified by X-ray diffraction analysis
and the morphologies of the reaction products were characterized using metallography and scanning electron microscopy (SEM).
The formation of products was also investigated by thermodynamic computation of free energies of the reactions and the study
of relevant equilibrium phase diagrams. The soluble species in the aqueous solutions of the reaction products were determined
quantitatively using atomic absorption spectrophotometry.
The high temperature interaction products usually contain a 3-phase structure namely, Na2O·M2O
x
, M2O
x
and metal sulphide and/or metal sulphate. The formation of Na2O·M2O
x
depends upon the solid state solubility of metal oxide in the molten salt at high temperatures. Under limited solubility
conditions Na2O·M2O
x
is invariably formed, but as soon as this condition is relaxed the oxide. M2O
x
, precipitates and forms a separate phase. 相似文献