全文获取类型
收费全文 | 286篇 |
免费 | 13篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 301篇 |
出版年
2023年 | 24篇 |
2022年 | 28篇 |
2021年 | 23篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 9篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 11篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有301条查询结果,搜索用时 0 毫秒
71.
72.
Niklas Paul Matthias Kraume Sebastian Schön Regine von Klitzing 《American Institute of Chemical Engineers》2015,61(3):1092-1104
In many industrial applications, the knowledge of the occurring transport processes in liquid/liquid systems is of great interest to design a multiphase reactor or an extraction column, for instance. All transport processes in liquid/liquid systems are governed by the interface. In some processes surfactants are needed. Surfactants change many interfacial properties which affect the transport processes. In this work, the influence of high surfactant concentrations (micellar systems) on transport processes is regarded. To understand, the occurring reduction of the drop rise velocity and of mass transfer rates experimental investigations of the occurring interfacial phenomena are carried out. Therefore, interfacial tension measurements as well as colloidal probe atomic force measurements of liquid/liquid systems were conducted. It was proved that for high nonionic surfactant concentrations a change of the phase behavior must be taken into consideration to describe transport processes in micellar liquid/liquid systems. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1092–1104, 2015 相似文献
73.
Kirsten Tracht Ann-Kathrin Onken Phil Gralla Joel Haji Emad Niklas Kipry Peter Maaß 《CIRP Annals》2018,67(1):9-12
In micro production, small tolerances, as well as size effects increase the requirement for a fast, precise, and reliable methodology that enhances the output of assemblies. In contrast to conventional approaches, a widening of the tolerance field enables an overall improvement of the output of a process chain while assuring functionality of parts. Therefore, the consideration of trends for building sections is essential for increasing the outcome by identifying sections that can be matched. This paper presents the Linked Parts Clustering Algorithm for the identification of trend-specific clusters in linked parts and demonstrates the area of application. 相似文献
74.
Niklas Elert 《The Annals of Regional Science》2014,53(1):55-92
In this paper, I examined what conditions affected the entry of Swedish limited liability firms 2000–2008, while making a distinction between regular entrants and those that survive for at least 2 years. I used a dataset that makes it possible to trace entry geographically as well as in what industry it occurs down to the 5-digit NACE level. Results suggest that the conditions influencing regular entry were similar to those influencing surviving entry. Political variables, e.g., municipal tax rate and the ideology of local rule, were of limited importance. Meanwhile, municipalities with industries with high minimum efficient scale of production or high market concentration rates were considerably less likely to see new firm formation. Substantially, more entry occurred in municipalities with high-income and a well-educated population. The importance of the level of education appears stronger for surviving entrants than for regular entrants, pointing to the importance of human capital. 相似文献
75.
Ahmed AbdulkadhimMoritz to Baben Volker SchnabelMarcus Hans Niklas ThiemeConrad Polzer Peter PolcikJochen M. Schneider 《Thin solid films》2012,520(6):1930-1933
X-ray amorphous V2AlC and hexagonal (V,Al)2Cx thin films were synthesized by magnetron sputtering from a compound target with the composition of V2AlC. The crystallization kinetics was investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). During continuous heating up to 1200 °C, one exothermal peak is observed between 565 and 675 °C. XRD data suggest that the DSC peak is associated with the formation of V2AlC. The activation energy of crystallization of V2AlC is ~ 308 kJ/mol based on the Kissinger approach. This value is close to the 287 kJ/mol activation energy obtained here for the transformation of magnetron sputtered (V,Al)2Cx thin films to V2AlC. The here reported phase formation temperature of V2AlC is about 800 °C lower than during hot pressing of elemental powders. 相似文献
76.
Ouattara L Mikkelsen A Sköld N Eriksson J Knaapen T Cavar E Seifert W Samuelson L Lundgren E 《Nano letters》2007,7(9):2859-2864
We directly image the interior of GaAs/AlGaAs axial and radial nanowire heterostructures with atomic-scale resolution using scanning tunneling microscopy. We show that formation of monolayer sharp and smooth axial interfaces are possible even by vapor-phase epitaxy. However, we also find that instability of the ternary alloys formed in the Au seed fundamentally limits axial heterostructure control, inducing large segment asymmetries. We study radial core-shell nanowires, imaging even ultrathin submonolayer shells. We demonstrate how large twinning-induced morphological defects at the wire surfaces can be removed, ensuring the formation of wires with atomically flat sides. 相似文献
77.
The influence of heat treatment parameters on the carbide morphology of the powder metallurgic high-speed steel HS 6-5-3-8 is examined. To that end, diverse heat treatment parameters are selected and applied by quenching dilatometry. In particular, different austenitizing temperatures, as well as an isothermal holding stage during quenching in the temperature regime of the transformation gap at temperatures between 450 and 600 °C, are produced. Extensive computer-aided image analysis is performed to investigate the carbide morphology. It is found that the circularity of the tungsten-rich M6C carbides increases significantly after short holding times at a temperature of 550 °C due to the carbide precipitation from metastable and supersaturated austenite onto pre-existing carbides. Longer holding times lead to further growth of the carbides, while the circularity of the carbides does not change. It is further shown that the hardness of the isothermally treated material is increased, all other parameters being equal. Increased carbide circularity might be helpful for increasing the toughness while reaching the same hardness and wear resistance as the conventional heat-treated material. Moreover, it might be possible to enhance the austenitizing temperature with regain of positive carbide morphology properties during the isothermal holding stage. Thus, improved material properties could be achieved. 相似文献
78.
Dr. Leandi van der Westhuizen Dr. Jörn Weisner Dr. Abu Taher Dr. Ina Landel Dr. Lena Quambusch Dr. Marius Lindemann Dr. Niklas Uhlenbrock Dr. Matthias P. Müller Prof. Ivan R. Green Dr. Stephen C. Pelly Prof. Daniel Rauh Prof. Willem A. L. van Otterlo 《ChemMedChem》2022,17(10):e202100776
Akt is a protein kinase that has been implicated in the progression of cancerous tumours. A number of covalent allosteric Akt inhibitors are known, and based on these scaffolds, a small library of novel potential covalent allosteric imidazopyridine-based inhibitors was designed. The envisaged compounds were synthesised, with click chemistry enabling a modular approach to a number of the target compounds. The binding modes, potencies and antiproliferative activities of these synthesised compounds were explored, thereby furthering the structure activity relationship knowledge of this class of Akt inhibitors. Three novel covalent inhibitors were identified, exhibiting moderate activity against Akt1 and various cancer cell lines, potentially paving the way for future covalent allosteric inhibitors with improved properties. 相似文献
79.
Futai Kouta Kolbe Niklas Notsu Hirofumi Suzuki Tasuku 《Journal of scientific computing》2022,90(2):1-30
Journal of Scientific Computing - In this paper, we propose and analyze a mixed finite element scheme for stationary inductionless magnetohydrodynamic equations on a general Lipschitz domain. We... 相似文献
80.
Zhiqiang Zeng Sven Küspert S. Esmael Balaghi Haytham E. M. Hussein Niklas Ortlieb Markus Knäbbeler-Buß Philipp Hügenell Stephan Pollitt Niclas Hug Julia Melke Anna Fischer 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(29):2205885
Platinum is one of the best-performing catalysts for the hydrogen evolution reaction (HER). However, high cost and scarcity severely hinder the large-scale application of Pt electrocatalysts. Constructing highly dispersed ultrasmall Platinum entities is thereby a very effective strategy to increase Pt utilization and mass activities, and reduce costs. Herein, highly dispersed Pt entities composed of a mixture of Pt single atoms, clusters, and nanoparticles are synthesized on mesoporous N-doped carbon nanospheres. The presence of Pt single atoms, clusters, and nanoparticles is demonstrated by combining among others aberration-corrected annular dark-field scanning transmission electron microscopy, X-ray absorption spectroscopy, and electrochemical CO stripping. The best catalyst exhibits excellent geometric and Pt HER mass activity, respectively ≈4 and 26 times higher than that of a commercial Pt/C reference and a Pt catalyst supported on nonporous N-doped carbon nanofibers with similar Pt loadings. Noteworthily, after optimization of the geometrical Pt electrode loading, the best catalyst exhibits ultrahigh Pt and catalyst mass activities (56 ± 3 A mg−1Pt and 11.7 ± 0.6 A mg−1Cat at −50 mV vs. reversible hydrogen electrode), which are respectively ≈1.5 and 58 times higher than the highest Pt and catalyst mass activities for Pt single-atom and cluster-based catalysts reported so far. 相似文献