共查询到11条相似文献,搜索用时 0 毫秒
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Fermi Level Pinning and Orbital Polarization Effects in Molecular Junctions: The Role of Metal Induced Gap States 下载免费PDF全文
Understanding the alignment of molecular orbitals and corresponding transmission peaks with respect to the Fermi level of the electrodes is a major challenge in the field of molecular electronics. In order to design functional devices, it is of utmost importance to assess whether controlled changes in the electronic structure of isolated compounds are preserved once they are inserted in the molecular junctions. Here, light is shed on this central issue by performing density functional theory calculations on junctions including diarylethene‐based molecules. It is demonstrated that the chemical potential equalization principle allows to rationalize the existence or not of a Fermi level pinning (i.e., same alignment in spite of a varying ionization potential in the isolated compounds), pointing to the essential role played by metal induced gap states (MIGS). It is further evidenced that the degree of level pinning is intimately linked to the degree of orbital polarization when a bias is applied between the two electrodes. 相似文献
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From Molecular‐Level Organization to Nanoscale Positioning: Synergetic Ligand Effect on the Synthesis of Hybrid Nanostructures 下载免费PDF全文
Di Xiang Hong Liu Lei Yang Yuting Liang Jiaqi Zhu Zhongyuan Lu Ying Hou Ming Yang 《Advanced functional materials》2017,27(45)
A key challenge in advancing the design of hybrid nanostructures (HNs) lies in the difficulty in mastering the principle of selected hybrid formation, which is complicated not only by the size and shape variations of nanoparticles but also by the interfacial phenomena associated with surface ligands. Here this study elaborates the formation mechanism of HNs by a combined experimental and theoretical study employing multiscale simulations and shows how molecular information encoded on particle surface can be transferred into distinct composite patterns. The emergence of different HNs is found to be not only related to ligand binding strengths affecting the reaction kinetics but also the ligand–ligand interactions responsible for phase segregation. Unexpectedly, the sulfidation of Ag nanoparticles co‐stabilized by citrate/gallic acid with different molar ratios constantly produces heterodimers with faster reaction rate than the formation of core–shell structures when they are solely coated by citrate or gallic acid. The surprising result originates from the phase separation of two short surface ligands with large contrast in binding strengths as indicated by photoluminescence spectra and supported by the dissipative particle dynamics simulations. Hierarchical HNs consisting of a heterodimer shell with built‐in hot spots can be further synthesized using Au@Ag core–shell particles with mixed surface layers. 相似文献
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Boris V. Sorokin Marina Pivetta Valerio Bellini Darius Merk Sébastien Reynaud Alessandro Barla Harald Brune Stefano Rusponi 《Advanced functional materials》2023,33(20):2213951
X-ray magnetic circular dichroism, atomic multiplet simulations, and density functional theory calculations are employed to identify criteria for the optimum combination of supporting alkaline earth oxide and adsorption site maximizing the spin lifetimes of lanthanide single-atom magnets. Dy and Ho atoms adsorbed on BaO(100) thin films on Pt(100) are characterized and compared with previous results for the same two elements on MgO/Ag(100). Dy shows hysteresis in magnetic fields up to ≈3.5 T and long spin lifetime, exceeding 300 s at 2.5 K and 0.5 T. Dy displays superior magnetic stability on the bridge site than on the top-O site. Surprisingly, Ho shows paramagnetism, as opposed to its long spin lifetime on MgO. These differences originate from the local surface distortions induced by the adatoms. On MgO, minimal distortions involve only the closest O atoms, while, on BaO, they affect both the closest anions and cations. This trend reflects the decrease of the lattice energy along the series of the alkaline earth oxides, going from MgO to BaO. This study represents a step ahead in the understanding of the factors determining the spin dynamics of surface-adsorbed single-atom magnets in order to achieve their operation as qubits and memories. 相似文献
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This study investigated psychological mechanisms underlying the effect of narrative health communication on behavioral intention. Specifically, the study examined how exemplification in news about successful smoking cessation affects recipients' narrative engagement, thereby changing their intention to quit smoking. Nationally representative samples of U.S. adult smokers participated in 2 experiments. The results from the 2 experiments consistently showed that smokers reading a news article with an exemplar experienced greater narrative engagement compared to those reading an article without an exemplar. Those who reported more engagement were in turn more likely to report greater smoking cessation intentions. 相似文献
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《IEEE transactions on bio-medical engineering》2009,56(12):2917-2926
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Johannes Ihli Yi‐Yeoun Kim Elizabeth H. Noel Fiona C. Meldrum 《Advanced functional materials》2013,23(12):1575-1585
Amorphous calcium carbonate (ACC) is an important intermediate in the formation of crystalline CaCO3 biominerals, where its crystallization is controlled using soluble additives. However, although this transformation often occurs in the solid state, experiments mainly focus on the effect of additives on ACC crystallization in solution. This paper addresses this issue and compares the crystallization, in solution and in the solid state, of ACC precipitated in the presence of a range of additives. Surprisingly, these results show that some additives exhibit a Janus behavior, where they retard crystallization in solution, yet accelerate it in the solid state. This is observed for all of the larger molecules examined, while the small molecules retard crystallization in both solution and the solid state. 相似文献
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Philipp Müller Christian Schemer Martin Wettstein Anne Schulz Dominique S. Wirz Sven Engesser Werner Wirth 《The Journal of communication》2017,67(6):968-992
This study explores how news messages carrying parts of the populist ideology contribute to a polarization of public opinion about populism. It combines a content analysis of news coverage on two policy areas (N = 7,119 stories) with a two-wave panel survey (N = 2,338) in four European metropolitan regions (Berlin, Paris, London, and Zurich). In three regions, unopposed media messages with a populist stance have a conditional effect on populist attitudes that depends on prior convictions. A higher dose of exposure to populist news coverage enhances both prior agreement and disagreement with populism. Although the observed interaction patterns vary between regions, the general picture suggests that populist messages in the news foster polarization between public support and disapproval of populism. 相似文献
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Transient behavior of the a-Si:H/Si3N4 metal-insulator-semiconductor (MIS) capacitor and its relationship to the performance of a-Si:H based active-matrix liquid crystal displays (AMLCDs) have been analyzed in detail. A relatively slow voltage decay whose time constant is comparable to the frame period of the LCD is observed after applying a voltage pulse that drives the MIS capacitor into the electron accumulation. The voltage decay is due to electron emission from the localized states at the a-Si:H/Si3N4 interface. It is also found that this voltage transient results in a shift in the optimum common voltage for the liquid crystal pixel by changing the temperature and light exposure when an MIS-type capacitor is inserted between the pixel electrode and the adjacent gate bus-line as the storage capacitor. This shift in the optimum common voltage affects the image quality of AMLCDs through image sticking or flicker. A similar effect can occur even without an MIS-type storage capacitor in high resolution AMLCDs, where the gate-source parasitic capacitance of the thin-film transistor is comparable to the net capacitance of the pixel. It is important to take such transient effects of MIS capacitors into consideration in pixel designing 相似文献