全文获取类型
收费全文 | 2225篇 |
免费 | 139篇 |
国内免费 | 16篇 |
专业分类
电工技术 | 46篇 |
综合类 | 6篇 |
化学工业 | 509篇 |
金属工艺 | 49篇 |
机械仪表 | 97篇 |
建筑科学 | 59篇 |
矿业工程 | 4篇 |
能源动力 | 136篇 |
轻工业 | 215篇 |
水利工程 | 20篇 |
石油天然气 | 31篇 |
无线电 | 227篇 |
一般工业技术 | 392篇 |
冶金工业 | 271篇 |
原子能技术 | 34篇 |
自动化技术 | 284篇 |
出版年
2024年 | 7篇 |
2023年 | 30篇 |
2022年 | 45篇 |
2021年 | 101篇 |
2020年 | 99篇 |
2019年 | 131篇 |
2018年 | 158篇 |
2017年 | 128篇 |
2016年 | 129篇 |
2015年 | 60篇 |
2014年 | 100篇 |
2013年 | 196篇 |
2012年 | 98篇 |
2011年 | 125篇 |
2010年 | 88篇 |
2009年 | 82篇 |
2008年 | 62篇 |
2007年 | 55篇 |
2006年 | 42篇 |
2005年 | 42篇 |
2004年 | 25篇 |
2003年 | 42篇 |
2002年 | 19篇 |
2001年 | 22篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 81篇 |
1997年 | 59篇 |
1996年 | 28篇 |
1995年 | 22篇 |
1994年 | 36篇 |
1993年 | 29篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 14篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 15篇 |
1985年 | 12篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 19篇 |
1981年 | 6篇 |
1979年 | 10篇 |
1977年 | 17篇 |
1976年 | 10篇 |
1975年 | 4篇 |
1970年 | 5篇 |
1966年 | 6篇 |
排序方式: 共有2380条查询结果,搜索用时 31 毫秒
1.
2.
3.
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
4.
Parisa Solhi Sodeif Azadmard‐Damirchi Javad Hesari Hamed Hamishehkar 《International Journal of Dairy Technology》2020,73(1):226-233
The qualitative properties of processed cheese (PC) fortified with different levels of asparagus powder (AP) (0.5%, 1% and 1.5% wt/wt) were evaluated during storage. AP decreased the pH and lipolysis indexes and increased the phenolic content, antioxidant activity and proteolysis of the processed cheeses. AP made the structure of the cheese more elastic, increased the rigidity and decreased the spreadability compared with the control sample, which corresponded to the results obtained using dynamic oscillatory rheometry. The results showed that AP as a rich source of bioactive components could be used for the fortification of processed cheeses. 相似文献
5.
Graded evolution of anisotropic microstructure during sintering from crystal-oriented powder compact
Shoko Baba Alexandre Maître Nicolas Pradeilles Guy Antou Nobuo Saito Satoshi Tanaka 《International Journal of Applied Ceramic Technology》2020,17(2):677-684
Anisotropic sintering, including shrinkage and grain growth, was examined for c-axis-oriented (Sr,Ca)2NaNb5O15 (SCNN) ceramics, which were prepared by colloidal processing under a magnetic field. In the c-axis-oriented SCNN powder compact, shrinkage and grain growth along the c-axis were higher than those along the a-axis. The anisotropic microstructural development was clearly associated with anisotropic sintering shrinkage. X-ray diffraction, scanning electron microscopy, and energy back scattering diffraction showed that the grain growth of oriented particles by including random grains contribute to the development of the oriented microstructure. Finally, the highly crystal-oriented SCNN ceramics with a densified microstructure were obtained through anisotropic sintering. These results clearly showed the potential to develop a well-defined anisotropic microstructure during sintering by designing and controlling the particle packing structure in a powder compact. 相似文献
6.
Discrete time queueing systems have been successfully used to model packet queues in computer and digital communications systems. In this article we introduce a novel approach to analyzing the GeoX/GeoY/∞ queueing system, which is suitable for modelling high speed computer and communications systems. The approach is based on characterizing the system by a functional equation which is then solved recursively to give identical results to those obtained using other approaches. 相似文献
7.
It is necessary to determine the accurate reflectance of painted surfaces for the review of paint finishes by computer graphics (CG) before actual painting of the exterior color of automobiles, and for quality control during production and inspection processes. We have optimized a method for measuring reflectance by using a statistical technique. We have found that the reflectance of a painted surface is best measured at an incident angle of 60° and at five aspecular angles of 10°, 18°, 28°, 40°, and 90°. Our method makes it possible to accurately reproduce reflection characteristics of paint finishes containing special flake pigments, such as pearl mica. Also it was proved that our method can apply not only to solid and metallic coatings but to all painted surfaces. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 275–282, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20125 相似文献
8.
9.
10.
M. Hamed 《Circuits, Systems, and Signal Processing》1997,16(1):41-58
This paper presents a comparison between the traditional image processing method and the area vector concept as well as the new technique of artificial neural networks. Freeman chain coding is considered in the study, and the principle of segmentation may be based and implemented for further investigations resulting from the proposed work. The pattern recognition concept is analyzed and defined through the sigmoid function and the determination of the threshold of a gray image for an object. The block schemes for the given protocols are summarized in a single scheme for illustration and comparison purposes. The synthetic pictures are generated and investigated regarding the dependence of computer vision on the contents of the artificial neural network. The normalization technique is included to eliminate noise and zooming problems. The minimum computational time for image processing with the generated pictures is also determined. The rate of deflection in the computational time is recommended for sensing the minimum computational time according to the variation of the number of hidden units in the hidden layer. A three-layer neural network has been used. The study of gray binary imaging for color pictures is illustrated to save computational time and effort. 相似文献