全文获取类型
收费全文 | 487篇 |
免费 | 34篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 226篇 |
金属工艺 | 9篇 |
机械仪表 | 8篇 |
建筑科学 | 17篇 |
能源动力 | 18篇 |
轻工业 | 30篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 19篇 |
一般工业技术 | 53篇 |
冶金工业 | 10篇 |
原子能技术 | 2篇 |
自动化技术 | 126篇 |
出版年
2024年 | 4篇 |
2023年 | 8篇 |
2022年 | 64篇 |
2021年 | 72篇 |
2020年 | 18篇 |
2019年 | 18篇 |
2018年 | 26篇 |
2017年 | 26篇 |
2016年 | 33篇 |
2015年 | 27篇 |
2014年 | 26篇 |
2013年 | 29篇 |
2012年 | 28篇 |
2011年 | 32篇 |
2010年 | 18篇 |
2009年 | 19篇 |
2008年 | 18篇 |
2007年 | 11篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1992年 | 2篇 |
1986年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有523条查询结果,搜索用时 10 毫秒
11.
Marta Valkov Pavel Letinský Lenka Matjov Kateina Klemencov Michal Ritz Christian Schimpf Mykhailo Motylenko David Rafaja Jakub Blík 《International journal of molecular sciences》2022,23(15)
Hematite (α-Fe2O3) catalysts prepared using the precipitation methods was found to be highly effective, and therefore, it was studied with methane (CH4), showing an excellent stable performance below 500 °C. This study investigates hematite nanoparticles (NPs) obtained by precipitation in water from the precursor of ferric chloride hexahydrate using precipitating agents NaOH or NH4OH at maintained pH 11 and calcined up to 500 °C for the catalytic oxidation of low concentrations of CH4 (5% by volume in air) at 500 °C to compare their structural state in a CH4 reducing environment. The conversion (%) of CH4 values decreasing with time was discussed according to the course of different transformation of goethite and hydrohematites NPs precursors to magnetite and the structural state of the calcined hydrohematites. The phase composition, the size and morphology of nanocrystallites, thermal transformation of precipitates and the specific surface area of the NPs were characterized in detail by X-ray powder diffraction, transmission electron microscopy, infrared spectroscopy, thermal TG/DTA analysis and nitrogen physisorption measurements. The results support the finding that after goethite dehydration, transformation to hydrohematite due to structurally incorporated water and vacancies is different from hydrohematite α-Fe2O3. The surface area SBET of Fe2O3_NH-70 precipitate composed of protohematite was larger by about 53 m2/g in comparison with Fe2O3_Na-70 precipitate composed of goethite. The oxidation of methane was positively influenced by the hydrohematites of the smaller particle size and the largest lattice volume containing structurally incorporated water and vacancies. 相似文献
12.
Tomasz Kostrzewa Jakub Joczyk Joanna Drzedon Dagmara Jacewicz Magdalena Grska-Ponikowska Marcin Koaczkowski Alicja Kuban-Jankowska 《International journal of molecular sciences》2022,23(13)
One of the main goals of recent bioinorganic chemistry studies has been to design and synthesize novel substances to treat human diseases. The promising compounds are metal-based and metal ion binding components such as vanadium-based compounds. The potential anticancer action of vanadium-based compounds is one of area of investigation in this field. In this study, we present five oxovanadium(IV) and dioxovanadium(V) complexes as potential PTP1B inhibitors with anticancer activity against the MCF-7 breast cancer cell line, the triple negative MDA-MB-231 breast cancer cell line, and the human keratinocyte HaCaT cell line. We observed that all tested compounds were effective inhibitors of PTP1B, which correlates with anticancer activity. [VO(dipic)(dmbipy)]·2 H2O (Compound 4) and [VOO(dipic)](2-phepyH)·H2O (Compound 5) possessed the greatest inhibitory effect, with IC50 185.4 ± 9.8 and 167.2 ± 8.0 nM, respectively. To obtain a better understanding of the relationship between the structure of the examined compounds and their activity, we performed a computer simulation of their binding inside the active site of PTP1B. We observed a stronger binding of complexes containing dipicolinic acid with PTP1B. Based on our simulations, we suggested that the studied complexes exert their activity by stabilizing the WPD-loop in an open position and limiting access to the P-loop. 相似文献
13.
14.
15.
The knowledge extraction is an important element of the e-Health system. In this paper, we introduce a new method for decision rules extraction called Graph-based Rules Inducer to support the medical interview in the diabetes treatment. The emphasis is put on the capability of hidden context change tracking. The context is understood as a set of all factors affecting patient condition. In order to follow context changes, a forgetting mechanism with a forgetting factor is implemented in the proposed algorithm. Moreover, to aggregate data, a graph representation is used and a limitation of the search space is proposed to protect from overfitting. We demonstrate the advantages of our approach in comparison with other methods through an empirical study on the Electricity benchmark data set in the classification task. Subsequently, our method is applied in the diabetes treatment as a tool supporting medical interviews. 相似文献
16.
Bruce G. Cameron Edward F. Crawley Jakub Kwapisz Alicia McNeill 《Engineering Management Journal; EMJ》2017,29(3):128-139
Platforming has become an important means of cost-sharing among industrial products. However, many firms face systemic downward pressure on commonality, with the result that many platforms realize less commonality than intended. Past research has hypothesized that divergence is the result of conflicting tensions between product customization/optimization and cost control. This article investigates the control and incentive levers available to platform managers to shape the behavior of the organization when divergence opportunities arise. Management levers are drawn from a series of 12 industrial case studies, stemming from investigations of the causes of divergences. These management levers are categorized as technical levers, financial levers, and organizational levers. This article illustrates each of the management levers with examples from the case studies. 相似文献
17.
Alena Reznickova Zdenka Kolska Jakub Siegel Vaclav Svorcik 《Journal of Materials Science》2012,47(17):6297-6304
Grafting of gold nanoparticles and nanorods on the surface of polymers, modified by plasma discharge, is studied with the aim to create structures with potential applications in electronics or tissue engineering. Surfaces of polyethyleneterephthalate and polytetrafluoroethylene were modified by plasma discharge and subsequently, grafted with 2-mercaptoethanol, 4,4′-biphenyldithiol, and cysteamine. The thiols are expected to be fixed via one of –OH, –SH or –NH2 groups to reactive places on the polymer surface created by the plasma treatment. “Free” –SH groups are allowed to interact (graft) with gold nanoparticles and nanorods. Gold nano-objects were characterized before grafting by transmission electron microscopy and UV–Vis spectroscopy. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and electrokinetic analysis (zeta potential determination) were used for the characterization of polymer surface at different modification phases. It was proved by FTIR and XPS measurements that the thiols were chemically bonded on the surface of the plasma-treated polymers, and they mediate subsequent grafting of the gold nano-objects. On the surfaces, modified polymers were indicated some objects by AFM, size of which was dramatically larger in comparison with that of original nanoparticles and nanorods. This result and the other results of UV–Vis spectroscopy indicate an aggregation of deposited gold nano-objects. 相似文献
18.
19.
Łukasz Szabłowski Jarosław Milewski Krzysztof Badyda Jakub Kupecki 《International Journal of Hydrogen Energy》2018,43(6):3555-3565
The idea of control strategy of SOFC operating to meet demand of a public utility building was presented. The strategy was formulated with the support of Artificial Neural Network. The network was used to predict the demand for electricity. The calculations were carried out on the example of a building of the Institute of Heat Engineering Warsaw University of Technology. The control strategy is influenced by various factors depending on changes in market conditions and operating characteristics of the cell. We can define different objective functions eg: working for own needs, for maximum profit and maximum service life. The article presents a simulation of SOFC operation for demand profile of the IHE building from the selected time period. 相似文献
20.
Jakub Galuszka 《Planning Theory & Practice》2019,20(3):395-419
Social movement-initiated co-production has been increasingly described as an approach that enables urban poor communities in the South to gain wider access to urban governance. However, with a predominant focus on project-level interventions, the case studies in which movements truly affect governance matters in a metro scale are rare. One of the examples involving such an achievement is the activism of civil society organisations and urban poor groups in Metro Manila, Philippines, which have succeeded to have a major impact on the housing and resettlement programme; the Oplan LIKAS. This article analyses how the civil society was able to gain such a position and the way it utilised it. The documentation of the challenges experienced by the civil society reflects the nature of co-productive engagement in the South and shows that it may easily reach its limits in an exclusionary governance setting. 相似文献