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排序方式: 共有392条查询结果,搜索用时 140 毫秒
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Ingolf Kahle Stefan Krause Cornelius Krasselt Alexander Jakob Alexander Oehlke Colin Georgi Steffen Schulze Heinrich Lang Michael Hietschold Stefan Spange Christian von Borczyskowski 《Applied Physics A: Materials Science & Processing》2014,115(2):617-625
Optical properties of nanomaterials such as semiconductor and metal quantum dots are important for sensors and photovoltaic applications. We report on optical, microscopic, and AFM investigations on bulk and single nanoobjects such as metal and semiconducting nanoparticles. Firstly, of special interest is the investigation of Ag metal nanoaggregates formed in zeolites. Here, the defined structure of the zeolite serves both as size directing and a stabilizing agent. The size selected Ag aggregates fluoresce in the zeolite cages even after storage under ambient conditions for almost one year. In addition, single Ag particles escape the cages and can be investigated by fluorescence microscopy also with respect to sensor applications. Secondly, with respect to photovoltaic applications, energy transfer among organic dye molecules and semiconductor quantum dots is of great importance. We report on the extension of the optical absorption of ZnSe quantum dots into the UV regime and investigate excitation energy transfer within self-assembled nanoaggregates of surface functionalized QDs and fluorescent styrylpyridine dyes. 相似文献
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Shchelkanova Mariya S. Shekhtman Georgi Sh. Kalashnova Anastasia V. Reznitskikh Olga G. 《Journal of Solid State Electrochemistry》2018,22(9):2959-2964
Journal of Solid State Electrochemistry - Lithium ion conductivity of lithium hexaoxozirconate Li8ZrO6 doped by Mg2+, Sr2+, Nb5+, V5+, and Ce4+ cations was studied using impedance spectroscopy. The... 相似文献
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A practical synthesis of new chiral aminophosphine ligands based on the camphane scaffold bearing alkoxy groups was accomplished. The application of these ligands in the Pd-catalyzed allylic alkylation of (E)-1,3-diphenyl-2-propenyl acetate proceeded with excellent conversions and ee’s of up to 91%. Variation of the alkoxy substituents did not substantially influence the catalytic performance. 相似文献
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Benjamin Klemmed Dr. Lucas V. Besteiro Dr. Albrecht Benad Maximilian Georgi Prof. Zhiming Wang Prof. Alexander Govorov Prof. Alexander Eychmüller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(4):1713-1719
Solar radiation is a versatile source of energy, convertible to different forms of power. A direct path to exploit it is the generation of heat, for applications including passive building heating, but it can also drive secondary energy-conversion steps. We present a novel concept for a hybrid material which is both strongly photo-absorbing and with superior characteristics for the insulation of heat. The combination of that two properties is rather unique, and make this material an optical superheater. To realize such a material, we are combining plasmonic nanoheaters with alumina aerogel. The aerogel has the double function of providing structural support for plasmonic nanocrystals, which serve as nanoheaters, and reducing the diffusion rate of the heat generated by them, resulting in large local temperature increases under a relatively low radiation intensity. This work includes theoretical discussion on the physical mechanisms impacting the system's balanced thermal equilibrium. 相似文献
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Kiril Kolikov Dragia Ivanov Georgi Krastev Yordan Epitropov Stefan Bozhkov 《Journal of Electrostatics》2012,70(1):91-96
In the paper we consider the problem of the electrostatic interaction between two charged conducting spheres with arbitrary electrical charges and radiuses. Using the image charges method we determine exact analytical formulas for the force F and for the potential energy W of the interaction between these two spheres as well as for the potential V of the electromagnetic field in an arbitrary point created by them. Our formulas lead to Coulomb’s law for point charges.We theoretically prove the experimentally shown fact that two spheres with the same type (positive or negative) of charges can also attract each other. 相似文献
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The peculiar propagator of scale invariant unparticles has phases that produce unusual patterns of interference with Standard Model processes. We illustrate some of these effects in e+e−→μ+μ−. 相似文献
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Andrea Preuß Marcus Korb Tobias Rüffer Jörn Bankwitz Colin Georgi Alexander Jakob Stefan E. Schulz Heinrich Lang 《无机化学与普通化学杂志》2020,646(13):670-680
The template synthesis of ethylenediamine ( 1 ) with 2-acetylcyclopentanone ( 2 ) and [Cu(OAc)2 · H2O] ( 5 ) produced [Cu(1-(2-cC5H6(O))C(Me)NCH2)2)] ( 6 ) in 82 % yield. Reaction of 5 with bis(benzoylacetone)diethylenetriamine ( 7 , = L H)[1] gave [Cu(μ-OAc)( L )(H2O)]2 ( 8 ). The solid-state structures of 6 and 8 were determined confirming that 8 possesses intra- and intermolecular hydrogen bonds resulting in a dimer formation. The thermal behavior of 6 – 8 was studied by TG and TG-MS. Under oxygen CuO was formed, whereas under Ar Cu/Cu2O ( 6 ) or Cu ( 8 ) was obtained. Complex 6 was used as CVD precursor for Cu and Cu-oxide deposition (substrate temp., 400–500 °C, N2, 60 mL · min–1; O2, 60 mL · min–1; pressure, 0.87–1.5 mbar). The as-obtained deposits show separated particles of different appearance at the substrate surface as evidenced by SEM. Non-volatile 8 was applied as spin-coating precursor for Cu and CuO formation [conc. 0.25 mol · L–1; volume 0.2 mL; 3000 rpm; depos. time 2 min; heating rate 50 K · min–1; holding time 60 min (Ar), 120 min (air) at 800 °C]. The samples on silicon consist of granulated particles (Ar) or are non-dense with a grainy topography (air). EDX and XPS measurements confirmed the formation of Cu (Ar) or CuO (O2) with up to 13 mol-% C impurity. 相似文献