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排序方式: 共有103条查询结果,搜索用时 109 毫秒
51.
Raoul Plessius Rosa Kromhout Dr. André Luis Dantas Ramos Dr. Marilena Ferbinteanu Dr. Marjo C. Mittelmeijer‐Hazeleger Prof. Rajamani Krishna Prof. Gadi Rothenberg Dr. Stefania Tanase 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(26):7922-7925
We present a new metal–organic framework (MOF) built from lanthanum and pyrazine‐2,5‐dicarboxylate (pyzdc) ions. This MOF, [La(pyzdc)1.5(H2O)2] ? 2 H2O, is microporous, with 1D channels that easily accommodate water molecules. Its framework is highly robust to dehydration/hydration cycles. Unusually for a MOF, it also features a high hydrothermal stability. This makes it an ideal candidate for air drying as well as for separating water/alcohol mixtures. The ability of the activated MOF to adsorb water selectively was evaluated by means of thermogravimetric analysis, powder and single‐crystal X‐ray diffraction and adsorption studies, indicating a maximum uptake of 1.2 mmol g?1 MOF. These results are in agreement with the microporous structure, which permits only water molecules to enter the channels (alcohols, including methanol, are simply too large). Transient breakthrough simulations using water/methanol mixtures confirm that such mixtures can be separated cleanly using this new MOF. 相似文献
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A Simple Synthesis of an N‐Doped Carbon ORR Catalyst: Hierarchical Micro/Meso/Macro Porosity and Graphitic Shells 下载免费PDF全文
Dr. David Eisenberg Wowa Stroek Ing. Norbert J. Geels Dr. Cosmin S. Sandu Prof. Dr. Adam Heller Dr. Ning Yan Prof. Dr. Gadi Rothenberg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):501-505
Replacing platinum as an oxygen reduction catalyst is an important scientific and technological challenge. Herein we report a simple synthesis of a complex carbon with very good oxygen reduction reaction (ORR) activity at pH 13. Pyrolysis of magnesium nitrilotriacetate yields a carbon with hierarchical micro/meso/macro porosity, resulting from in situ templating by spontaneously forming MgO nanoparticles and from etching by pyrolysis gases. The mesopores are lined with highly graphitic shells. The high ORR activity is attributed to a good balance between high specific surface area and mass transport through the hierarchical porosity, and to improved electronic conductivity through the graphitic shells. This novel carbon has a high surface area (1320 m2g?1), and high nitrogen content for a single precursor synthesis (~6 %). Importantly, its synthesis is both cheap and easily scalable. 相似文献
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A novel phase-only sampled 45 channel fiber Bragg grating (channel spacing, 100 GHz) with high interchannel and intrachannel reflection uniformity and precise dispersion matching capability to an 80 km SMF-28 fiber is demonstrated. This grating is fabricated by the side-writing technique, in which phase information of continuous phase-only sampling is completely incorporated into a diffraction-compensated phase mask. 相似文献
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Ma Xintong Li Sirui Ronda-Lloret Maria Chaudhary Rohit Lin Liangliang van Rooij Gerard Gallucci Fausto Rothenberg Gadi Raveendran Shiju N. Hessel Volker 《Plasma Chemistry and Plasma Processing》2019,39(1):109-124
Plasma Chemistry and Plasma Processing - We present an innovative approach for reacting carbon dioxide and water to give syngas by combining heterogeneous catalysis and non-thermal plasma... 相似文献
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Cheung EC Ho JG Goodno GD Rice RR Rothenberg J Thielen P Weber M Wickham M 《Optics letters》2008,33(4):354-356
A diffractive optical element (DOE) is used as a beam combiner for an actively phase-locked array of fiber lasers. Use of a DOE eliminates the far-field sidelobes and the accompanying loss of beam quality typically observed in tiled coherent laser arrays. Using this technique, we demonstrated coherent combination of five fiber lasers with 91% efficiency and M2=1.04. Combination efficiency and phase locking is robust even with large amplitude and phase fluctuations on the input laser array elements. Calculations and power handling measurements suggest that this approach can scale to both high channel counts and high powers. 相似文献
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Previous research on the special characteristics of the professional singing voice has at least partially explained how singers can commonly use much higher lung pressures than nonsingers without vocal damage or excessive air flow during the voiced sounds. In this study, the control of air flow during the unvoiced consonants is examined for an operatic-style soprano. It was found that this singer could maintain a low average air flow during the consonants even though the lung pressure reached values over five times those used during normal conversational speech. The air flow was kept low primarily by the use of a number of mechanisms involving rapid, accurate, coordinated valving of the air flow at the point of articulation and at the glottis. 相似文献
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