全文获取类型
收费全文 | 3027篇 |
免费 | 237篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 28篇 |
综合类 | 1篇 |
化学工业 | 821篇 |
金属工艺 | 52篇 |
机械仪表 | 83篇 |
建筑科学 | 110篇 |
矿业工程 | 11篇 |
能源动力 | 104篇 |
轻工业 | 506篇 |
水利工程 | 21篇 |
石油天然气 | 13篇 |
无线电 | 198篇 |
一般工业技术 | 437篇 |
冶金工业 | 228篇 |
原子能技术 | 25篇 |
自动化技术 | 629篇 |
出版年
2024年 | 9篇 |
2023年 | 45篇 |
2022年 | 113篇 |
2021年 | 163篇 |
2020年 | 91篇 |
2019年 | 108篇 |
2018年 | 126篇 |
2017年 | 112篇 |
2016年 | 155篇 |
2015年 | 103篇 |
2014年 | 158篇 |
2013年 | 275篇 |
2012年 | 208篇 |
2011年 | 229篇 |
2010年 | 159篇 |
2009年 | 150篇 |
2008年 | 145篇 |
2007年 | 132篇 |
2006年 | 88篇 |
2005年 | 76篇 |
2004年 | 77篇 |
2003年 | 54篇 |
2002年 | 63篇 |
2001年 | 40篇 |
2000年 | 29篇 |
1999年 | 32篇 |
1998年 | 56篇 |
1997年 | 49篇 |
1996年 | 31篇 |
1995年 | 30篇 |
1994年 | 20篇 |
1993年 | 16篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1977年 | 3篇 |
1976年 | 8篇 |
1973年 | 3篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有3267条查询结果,搜索用时 13 毫秒
991.
Rafael Alcalá Jesús Alcalá-Fdez Jorge Casillas Oscar Cordón Francisco Herrera 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2006,10(9):717-734
One of the problems associated to linguistic fuzzy modeling is its lack of accuracy when modeling some complex systems. To overcome this problem, many different possibilities of improving the accuracy of linguistic fuzzy modeling have been considered in the specialized literature. We will call these approaches as basic refinement approaches. In this work, we present a short study of how these basic approaches can be combined to obtain new hybrid approaches presenting a better trade-off between interpretability and accuracy. As an example of application of these kinds of systems, we analyze seven hybrid approaches to develop accurate and still interpretable fuzzy rule-based systems, which will be tested considering two real-world problems.This work has been supported by the spanish cicyt project tic2002-04036-c05-01 (keel). 相似文献
992.
Alba Tres Carla Daniela Nuchi Ricard Bou Rafael Codony Francesc Guardiola 《European Journal of Lipid Science and Technology》2009,111(6):563-573
We used an induced version of the FOX method to assess the oxidative stability of meats. Formerly, this induced version only measured the lipid hydroperoxide (LHP) value once the ferrous oxidation‐xylenol orange (FOX) reaction had reached a plateau. However, samples could have similar final LHP values that were reached in different ways. Thus, there may be variations in the samples' susceptibility to oxidation that are not detected by a final measurement of the LHP value. If the LHP value is measured at different points in the FOX reaction, it might be possible to calculate parameters such as induction time, oxidation rate, maximum LHP value, time of maximum LHP value and area under the curve. Such parameters might provide deeper insight into the evolution of oxidation in each sample than a final measurement of the LHP value. However, the accuracy of the measurement of these parameters could depend on the number of LHP measurements that can be taken during the FOX reaction. This improvement in the FOX method for assessing sample susceptibility to oxidation was applied to meats and other tissues such as liver. 相似文献
993.
William R. Hesse Langli Luo Guangneng Zhang Rafael Mulero Junghyun Cho Min Jun Kim 《Materials science & engineering. C, Materials for biological applications》2009,29(7):2282-2286
Flagella isolated from Salmonella typhimurium were used as a template for the formation of TiO2 nanotubes, which was accomplished through recent advances in low temperature ceramic film processing. TiO2 is precipitated onto or attracted to the flagellar surface in aqueous solution. The mechanism of mineral film formation is similar to that of biominerals in nacre, sea urchin spine, and sponge spicule. This process is advantageous over other mineralization processes, as no genetic modification of the flagella is necessary and the mineralization is done at low temperature in aqueous solution. 相似文献
994.
The effects of pyrrole, anthraquinone‐2‐sulphonic acid (AQSA) and iron(III) chloride (FeCl3) concentrations, reaction time and temperature on the electrical conductivity of polypyrrole (PPy)—coated poly(ethylene terephthalate) (PET) fabrics were investigated. With an increase in both the AQSA and FeCl3 concentrations, resistivity decreased to a point beyond which higher concentrations led to increased surface resistivity. Erosion of the polymer coating, in dynamic synthesis from continual abrasion, manifested as an exponential increase in the resistance of the coated textile substrate. This was not encountered in static synthesis conditions. Temperature affected the degree of surface and bulk polymerisation. The effect of polymerisation temperature on conductivity was negligible. Conductive polymer coating on textiles through chemical polymerisation enabled a smooth coherent film to encase individual fibres, which did not affect the tactile properties of the host substrate. The optimum FeCl3/pyrrole and AQSA FeCl3/pyrrole molar ratios were found to be 2.22 and 0.40 respectively. Copyright © 2003 Society of Chemical Industry 相似文献
995.
Kü hnle Matthias Hü bner Michael Becker Jü rgen Deledda Antonio Mucci Claudio Ries Florian Coppola Antonio Marcello Pieralisi Lorenzo Locatelli Riccardo Maruccia Giuseppe DeMarco Tommaso Campi Fabio 《Design & Test of Computers, IEEE》2008,25(5):442-451
Editor's note:The diversification of the SoC market has increased the need for domain-specific programmable platforms that can be tailored to postfabrication products. This article presents a design case study on the interconnect for such a programmable platform, as part of the Morpheus project.—Li-Shiuan Peh, Princeton University 相似文献
996.
997.
Fábio A. Cardoso Anne K. Agopyan Carlos Carbone Rafael G. Pileggi Vanderley M. John 《Construction and Building Materials》2009,23(3):1349-1353
This paper presents a rheological investigation of pure gypsum (PG) and a commercial gypsum–lime–filler plaster (CP) using the modified Vicat apparatus and squeeze flow method. The samples were tested at several different intervals after manual or mechanical mixing. The results confirmed squeeze flow to be more sensitive in determining fresh paste behavior than the modified Vicat apparatus. PG set faster when prepared in mechanical mixer than when manually mixed. Conversely, the CP composition presented longer setting when mixed mechanically. The study also included the analysis of two ready-to-use polymer-based products for leveling and rendering (drywall joint compound – DJC; acrylic putty – AP) measured by squeeze flow and compared to the commercial composition. 相似文献
998.
999.
1000.
The International Sourcing Problem consists of selecting a subset from an available set of potential suppliers internationally located. The selected suppliers must meet the demand for items from a set of plants, which are also located worldwide. Since the costs are affected by macroeconomic conditions in the countries where the supplier and the plant are located, the formulation considers the uncertainty associated with changes in these conditions. We formulate the robust capacitated international sourcing problem by means of a scenario-optimization approach. When dealing with uncertainty, one of the most common approaches in the literature is to formulate the problem via a set of possible scenarios, this is the approach we follow here. In this paper we propose a constructive method based on memory structures to solve this problem. The method is coupled with a local search procedure followed by a path relinking for improved outcomes. We propose an innovative mechanism to achieve a good balance between intensification and diversification in the search process. Moreover, our path-relinking implementation uses constructive neighborhoods for extrapolated relinking. The computational experimentation favors this method when compared with a recent tabu search approach. 相似文献