全文获取类型
收费全文 | 374篇 |
免费 | 36篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 130篇 |
金属工艺 | 1篇 |
机械仪表 | 3篇 |
建筑科学 | 13篇 |
能源动力 | 6篇 |
轻工业 | 79篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
无线电 | 6篇 |
一般工业技术 | 50篇 |
冶金工业 | 45篇 |
自动化技术 | 63篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 28篇 |
2020年 | 18篇 |
2019年 | 26篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 16篇 |
2013年 | 28篇 |
2012年 | 30篇 |
2011年 | 31篇 |
2010年 | 25篇 |
2009年 | 19篇 |
2008年 | 17篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有410条查询结果,搜索用时 62 毫秒
31.
Rodrigo Máximo Sánchez-Román Marcos Vinicius Folegatti Alba María Guadalupe Orellana González 《Water Resources Management》2010,24(4):761-773
The Piracicaba, Capivari, and Jundiaí River Basins (RB-PCJ) are mainly located in the State of São Paulo, Brazil. Using a dynamics systems simulation model (WRM-PCJ) to assess water resources sustainability, five 50-year simulations were run. WRM-PCJ was developed as a tool to aid decision and policy makers on the RB-PCJ Watershed Committee. The model has 254 variables. The model was calibrated and validated using available information from the 80s. Falkenmark Water Stress Index went from 1,403 m3 person???1 year???1 in 2004 to 734 m3 P???1 year???1 in 2054, and Xu Sustainability Index from 0.44 to 0.20. In 2004, the Keller River Basin Development Phase was Conservation, and by 2054 was Augmentation. The three criteria used to evaluate water resources showed that the watershed is at crucial water resources management turning point. The WRM-PCJ performed well, and it proved to be an excellent tool for decision and policy makers at RB-PCJ. 相似文献
32.
Clio Azina Tim Bartsch Damian M. Holzapfel Martin Dahlqvist Johanna Rosen Lukas Löfler Alba San Jose Mendez Marcus Hans Daniel Primetzhofer Jochen M. Schneider 《Journal of the American Ceramic Society》2023,106(4):2652-2665
Herein we report on the synthesis of a metastable (Cr,Y)2AlC MAX phase solid solution by co-sputtering from a composite Cr–Al–C and elemental Y target, at room temperature, followed by annealing. However, direct high-temperature synthesis resulted in multiphase films, as evidenced by X-ray diffraction analyses, room-temperature depositions, followed by annealing to 760°C led to the formation of phase pure (Cr,Y)2AlC by diffusion. Higher annealing temperatures caused a decomposition of the metastable phase into Cr2AlC, Y5Al3, and Cr-carbides. In contrast to pure Cr2AlC, the Y-containing phase crystallizes directly in the MAX phase structure instead of first forming a disordered solid solution. Furthermore, the crystallization temperature was shown to be Y-content dependent and was increased by ∼200°C for 5 at.% Y compared to Cr2AlC. Calculations predicting the metastable phase formation of (Cr,Y)2AlC and its decomposition are in excellent agreement with the experimental findings. 相似文献
33.
J. García-Nieto E. Alba A. Carolina Olivera 《Engineering Applications of Artificial Intelligence》2012,25(2):274-283
Congestion, pollution, security, parking, noise, and many other problems derived from vehicular traffic are present every day in most cities around the world. The growing number of traffic lights that control the vehicular flow requires a complex scheduling, and hence, automatic systems are indispensable nowadays for optimally tackling this task. In this work, we propose a Swarm Intelligence approach to find successful cycle programs of traffic lights. Using a microscopic traffic simulator, the solutions obtained by our algorithm are evaluated in the context of two large and heterogeneous metropolitan areas located in the cities of Málaga and Sevilla (in Spain). In comparison with cycle programs predefined by experts (close to real ones), our proposal obtains significant profits in terms of two main indicators: the number of vehicles that reach their destinations on time and the global trip time. 相似文献
34.
The Spanish wholesale electricity market started on January 1st 1998. Though it is based on simple price/quantity bids, it incorporates some provisions to take thermal plant running requirements into account. This paper presents these rules and its mathematical treatment, focusing on a possible implementation of the “minimum income condition”, which allows thermal generators to declare minimum stable loads. It also shows another key point in the debate: whether the algorithm should minimize costs or consumer payments 相似文献
35.
Mercedes Aleman Carla Daniela Nuchi Ricard Bou Alba Tres Javier Polo Francesc Guardiola Rafael Codony 《European Journal of Lipid Science and Technology》2010,112(7):761-769
Bakery products such as biscuits, cookies, and pastries represent a good medium for iron fortification in food products, since they are consumed by a large proportion of the population at risk of developing iron deficiency anemia, mainly children. The drawback, however, is that iron fortification can promote oxidation. To assess the extent of this, palm oil added with heme iron and different antioxidants was used as a model for evaluating the oxidative stability of some bakery products, such as baked goods containing chocolate. The palm oil samples were heated at 220°C for 10 min to mimic the conditions found during a typical baking processing. The selected antioxidants were a free radical scavenger (tocopherol extract (TE), 0 and 500 mg/kg), an oxygen scavenger (ascorbyl palmitate (AP), 0 and 500 mg/kg), and a chelating agent (citric acid (CA), 0 and 300 mg/kg). These antioxidants were combined using a factorial design and were compared to a control sample, which was not supplemented with antioxidants. Primary (peroxide value and lipid hydroperoxide content) and secondary oxidation parameters (p‐anisidine value, p‐AnV) were monitored over a period of 200 days in storage at room temperature. The combination of AP and CA was the most effective treatment in delaying the onset of oxidation. TE was not effective in preventing oxidation. The p‐AnV did not increase during the storage period, indicating that this oxidation marker was not suitable for monitoring oxidation in this model. 相似文献
36.
Alba L. Ramaswamy 《Journal of Energetic Materials》2013,31(2-3):195-217
Abstract The sensitivity to initiation of different crystalline polymorphic forms of the same energetic material is known to differ. Similarly single crystals of energetic materials such as PETN and nitromethane show a shock initiation sensitivity anisotropy. The crystal structure of the energetic materials is thus known to control the initiation sensitivity of the same. As will be described in this paper there is evidence to indicate that the orientation of the molecules surrounding a given molecule in the crystal lattice, influences the initial decomposition reaction of the molecule. Several microscopic mechanisms of initiation have been postulated. It is shown here that added to and above these mechanisms the crystal structure can be taken into account in a metastable intermolecular trigger reaction which explains the observed differences in initiation as a function of crystal structure. 相似文献
37.
Rodriguez-Garcia J.D. Guerra O. Roca E. Fernandez F.V. Rodriguez-Vazquez A. 《Electronics letters》1999,35(4):260-261
Circuit reduction is a fundamental first step in addressing the symbolic analysis of large analogue circuits. A new algorithm for simplification before generation is presented which is very efficient in terms of speed and the amount of circuit reduction, and solves the accuracy problems of previously reported approaches 相似文献
38.
Gulya Michelle; Rossi-George Alba; Rovee-Collier Carolyn 《Canadian Metallurgical Quarterly》2002,28(2):151
In 3 experiments with 85 human 3-month-olds, the authors asked whether retroactive interference with their memory of the original training stimulus is temporary or permanent. Infants learned to move a mobile by kicking and then were exposed to a different mobile (Exp 1) or context (Exp 2) immediately or 3 days afterward (Exp 3). They were tested after increasing delays with the original stimulus, the exposed stimulus, or a completely novel stimulus. Retroactive interference was temporary and unrelated to the exposure delay. The data are consistent with a retrieval-based account of interference. Memory updating (i.e., responding to the interfering stimulus) was coincident with retroactive interference, suggesting that retroactive interference is an adaptive mechanism that facilitates memory updating within a narrow time window. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
39.
Forecasting airborne pollen concentration time series with neural and neuro-fuzzy models 总被引:3,自引:0,他引:3
Jos Luis Aznarte M. Jos Manuel Benítez Snchez Diego Nieto Lugilde Concepcin de Linares Fernndez Consuelo Díaz de la Guardia Francisca Alba Snchez 《Expert systems with applications》2007,32(4):1218-1225
Forecasting airborne pollen concentrations is one of the most studied topics in aerobiology, due to its crucial application to allergology. The most used tools for this problem are single lineal regressions and autoregressive models (ARIMA). Notwithstanding, few works have used more sophisticated tools based in Artificial Intelligence, as are neural or neuro-fuzzy models. In this work, we applied some of these models to forecast olive pollen concentrations in the atmosphere of Granada (Spain). We first studied the overall performance of the selected models, then considering the data segmented into intervals (low, medium and high concentration), to test how they behave on each interval. Experimental results show an advantage of the neuro-fuzzy models against classical statistical methods, although there is still room for improvement.1 相似文献
40.
Bentosela Mariana; Ruetti Eliana; Muzio Rubén N.; Mustaca Alba E.; Papini Mauricio R. 《Canadian Metallurgical Quarterly》2006,120(2):371
Rats given access to a 32% sucrose solution and then downshifted to a 4% solution exhibit less contact with the sipper tube than unshifted controls always given access to 4% solution. This phenomenon, called consummatory successive negative contrast, was facilitated in Experiment 1 by a posttrial injection of corticosterone (3 mg/kg) administered immediately after the first downshift trial. Experiment 2 demonstrated that this facilitatory effect of posttrial corticosterone does not occur when administered 3 hr after the first downshift trial. These results support the hypothesis that corticosterone strengthens an aversive emotional component elicited by the surprising downshift in reward magnitude during the initial downshift trial. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献