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41.
Matt Apanius Pankaj B. Kaul Alexis R. Abramson 《Sensors and actuators. A, Physical》2007,140(2):168-175
Pattern deposition of metals with controlled and microscale dimensions can be a challenging task if traditional photolithography is not a practical option. This is a particularly valid concern for the case of certain polymer substrates, which are gaining in importance in the microelectronics and related industries. Therefore, a novel design and process flow for batch fabricating low cost reusable silicon shadow masks was developed. Of note was the corner compensation scheme employed to avoid over-etching of the convex corners in the design. These shadow masks enabled deposition of metals or other suitable materials with feature sizes ranging from approximately 3 to 250 μm and were successfully utilized to form patterned metal heater lines and pads on various samples. The heaters, required for conducting thermal conductivity measurements of the underlying films/substrates using the three omega (3ω) method, showed resistance–temperature linearity, confirming theoretical estimates to within 0.2%. Moreover, the room temperature thermal conductivity of an amorphous SiO2 film as well as a polyaniline thick film were measured, further validating the deposition through shadow mask technique. 相似文献
42.
Werner Alpers Alexis Mouche Jochen Horstmann Andrei Yu. Ivanov Vladyslav S. Barabanov 《International journal of remote sensing》2013,34(3):863-881
Several algorithms have been proposed to retrieve near-surface wind fields from C-band synthetic aperture radar (SAR) images acquired over the ocean. They mainly differ in the way they retrieve the wind direction. Conventionally, the wind direction is taken from atmospheric models or is extracted from the linear features sometimes visible in SAR images. Recently, a new wind retrieval algorithm has been proposed, which also includes the Doppler shift induced by motions of the sea surface. In this article, we apply three wind retrieval algorithms, including the one using Doppler information, to three complex wind events encountered over the Black Sea and compare the SAR-derived wind fields with model wind fields calculated using the high-resolution weather research and forecasting (WRF) model. It is shown that the new algorithm is very efficient in resolving the 180° ambiguity in the wind direction, which is often a problem in the streak-based wind retrieval algorithms. However, the Doppler-based algorithm only yields good results for wind directions that have a significant component in the look direction of the SAR antenna. Furthermore, it is dependent on good separation of the contributions to the Doppler shift induced by surface currents and wind-related effects (wind drift and wind-sea components of the ocean wave spectrum). We conclude that an optimum wind retrieval algorithm should consist of a combination of the algorithms based on linear features and Doppler information. 相似文献
43.
Yan Duan Shengnan Sun Yuanmiao Sun Shibo Xi Xiao Chi Qinghua Zhang Xiao Ren Jingxian Wang Samuel Jun Hoong Ong Yonghua Du Lin Gu Alexis Grimaud Zhichuan J. Xu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(12)
Developing highly active electrocatalysts for oxygen evolution reaction (OER) is critical for the effectiveness of water splitting. Low‐cost spinel oxides have attracted increasing interest as alternatives to noble metal–based OER catalysts. A rational design of spinel catalysts can be guided by studying the structural/elemental properties that determine the reaction mechanism and activity. Here, using density functional theory (DFT) calculations, it is found that the relative position of O p‐band and MOh (Co and Ni in octahedron) d‐band center in ZnCo2?xNixO4 (x = 0–2) correlates with its stability as well as the possibility for lattice oxygen to participate in OER. Therefore, it is testified by synthesizing ZnCo2?xNixO4 spinel oxides, investigating their OER performance and surface evolution. Stable ZnCo2?xNixO4 (x = 0–0.4) follows adsorbate evolving mechanism under OER conditions. Lattice oxygen participates in the OER of metastable ZnCo2?xNixO4 (x = 0.6, 0.8) which gives rise to continuously formed oxyhydroxide as surface‐active species and consequently enhances activity. ZnCo1.2Ni0.8O4 exhibits performance superior to the benchmarked IrO2. This work illuminates the design of highly active metastable spinel electrocatalysts through the prediction of the reaction mechanism and OER activity by determining the relative positions of the O p‐band and the MOh d‐band center. 相似文献
44.
45.
Bovet C Ruff M Eiler S Granger F Wenzel R Nazabal A Moras D Zenobi R 《Analytical chemistry》2008,80(20):7833-7839
Many drugs and chemicals exert their biological effect by modulating protein-protein interactions. In vitro approaches to characterize these mechanisms are often based on indirect measurements (e.g., fluorescence). Here, we used mass spectrometry (MS) to directly monitor the effect of small-molecule ligands on the binding of a coactivator peptide (SRC1) by the human estrogen receptor alpha ligand binding domain (hERalpha LBD). Nanoelectrospray mass spectrometry (nanoESI-MS) and high-mass matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with chemical cross-linking were employed to follow these processes. The chemical cross-linking protocol used prior to high-mass MALDI analysis allows detection of intact noncovalent complexes. The binding of intact hERalpha LBD homodimer with two coactivator peptides was detected with nanoESI-MS and high-mass MALDI-MS only in the presence of an agonist ligand. Furthermore, high-mass MALDI-MS revealed an increase of the homodimer abundance after incubating the receptor with a ligand, independent of the ligand character (i.e., agonist, antagonist). The binding characteristics of the compounds tested by MS correlate very well with their biological activity reported by cell-based assays. High-mass MALDI appears to be an efficient and simple tool for directly monitoring ligand regulation mechanisms involved in protein-protein interactions. Furthermore, the combination of both MS methods allows identifying and characterizing endocrine-disrupting compounds or new drug compounds in an efficient way. 相似文献
46.
47.
Stefania De Rosa Paolo Branchini Valentina Spampinato Alexis Franquet Rossella Yivlialin Lamberto Duo Gianlorenzo Bussetti Luca Tortora 《Nano Research》2022,(2):1120-1127
A detailed stratigraphic investigation of the intercalation mechanism when graphite electrodes are immersed inside diluted perchloric(HClO4)and sulfuric(H2SO4)electrolytes is obtained by comparing results when graphite crystals are simply immersed in the same acid solutions.By combining time-of-flight secondary ion mass spectrometry(ToF-SIMS)and in-situ atomic force microscopy(AFM),we provide a picture of the chemical species involved in the intercalation reaction.The depth intensity profile of the ion signals along the electrode crystal clearly shows a more complex mechanism for the intercalation process,where the local morphology of the basal plane plays a crucial role.Solvated anions are mostly located within the first tens of nanometers of graphite,but electrolytes also diffuse inside the buried layers for hundreds of nanometers,the latter process is also aided by the presence of mesoscopic crystal defects.Residual material from the electrolyte solution was found localized in well-defined circular spots,which represent preferential interaction areas.Interestingly,blister-like micro-structures similar to those observed on the highly oriented pyrolytic graphite(HOPG)surface were found in the buried layers,confirming the equivalence of the chemical condition on the graphite surface and in the underneath layers. 相似文献
48.
Alexis De Vos 《Electronic Notes in Theoretical Computer Science》2010,253(6):17-22
Conventional logic gates (e.g. AND gates) cannot be used for building a reversible computer. An appropriate design approach is necessary. Both small building blocks and a more complex circuit in MOS technology are presented. Today, these are useful in low-power digital electronics. Tomorrow, these may be useful in quantum computers. 相似文献
49.
Michael Beetz Freek Stulp Piotr Esden-Tempski Andreas Fedrizzi Ulrich Klank Ingo Kresse Alexis Maldonado Federico Ruiz 《Autonomous Robots》2010,28(1):21-44
This article investigates methods for achieving more general manipulation capabilities for mobile manipulation platforms, which produce legible behavior in human living environments. To achieve generality and legibility, we combine two control mechanisms. First of all, experience- and observation-based learning of skills is applied to routine tasks, so that the repetitive and stereotypical character of everyday activity is exploited. Second, we use planning, reasoning, and search for novel tasks which have no stereotypical solution. We apply these ideas to the learning and use of action-related places, to the model-based visual recognition and localization of objects, and the learning and application of reaching strategies and motions from humans. We demonstrate the integration of these mechanisms into a single low-level control system for autonomous manipulation platforms. 相似文献
50.
Tjokorde W. Samadhi Linda E. Jones Alexis G. Clare 《Journal of the American Ceramic Society》2003,86(12):2044-2049
Carbon reacts with Na2 SO4 in glass batches, influencing SO x emissions. To study the role of carbon active surface area (ASA) in the decomposition phenomena, Na2 SO4 is reacted with three carbons with a wide ASA range. The decomposition behavior was evaluated by thermogravimetric analysis (TGA) and evolved gas analysis via mass spectrometry and Fourier transform infrared spectrometry. Higher carbon ASA yields lower decomposition temperatures. SO x emissions are realized at temperatures as low as 773 K. Isothermal Na2 SO4 –C decomposition initiates via the nucleation of Na2 S. The rate constants for the nucleation regime are normalized against ASA, yielding an activation energy of 275 kJ/mol for nucleation. 相似文献