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991.
采用溶剂热法合成了三种M(HBTC)(4,4’-bipy)·3DMF(M=Ni,Co,Zn,HBTC=1,3,5-均苯三甲酸,4,4’-bipy=4,4′-联吡啶)结构的支柱层金属有机骨架材料(MOFs).首次采用溶剂热和微波法合成了Zn(HBTC)(4,4’-bipy)·3DMF,并采用多种物理化学方法对其进行了表征.M(HBTC)(4,4’-bipy)·3DMF中包含有M2+离子的蜂窝网格层和BTC单元,BTC单元与4,4’-联吡啶柱进一步交联形成三维多孔骨架材料.在采用烷基铵卤化物作为助催化剂和无溶剂的条件下,所有MOFs材料均对催化固定CO_2与环氧化合物环加成制备环状碳酸酯反应表现出非常好的协同催化性能,其催化活性高低顺序为:ZnCoNi,这可通过酸-碱双功能特性进行解释.采用微波法合成的Zn(HBTC)(4,4’-bipy)·3DMF材料表现出与常规催化剂相似的物理化学性质和催化性能.考察了不同制备参数的影响和材料的重复使用性能,并提出了该反应的可能机理 相似文献
992.
Jiyeon KangKyeong-Ju Moon Tae Il LeeWoong Lee Jae-Min Myoung 《Applied Surface Science》2012,258(8):3509-3512
Electromigration of In in amorphous indium-gallium-zinc-oxide thin film transistors under repeated switching operation was investigated by analyzing the distribution of component elements. During the repeated switching operations up to 300 times, threshold voltage of this device increased gradually implying alteration to the internal device structures. Energy dispersive X-ray spectroscopy revealed noticeable redistribution of metallic components, especially In, in the channel layer beneath the source electrode during switching operations by the migration of metallic ions away from the source electrode, which is attributed to electromigrations similar to those observed in organic light emitting diodes having indium tin oxide electrodes. 相似文献
993.
Tae-Wook Kim Seul-Kee Kim Sungkyun Park Kang Hyun Park Jae-Myung Lee 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):145-159
The present study investigated thermal and mechanical characteristics of irradiated polyurethane foams (PUFs) according to the irradiation does under various temperature conditions, including low/cryogenic temperatures. Fourier transform infrared analysis was performed to obtain information on the PUF molecular structure. In addition, Macro- and microstructural investigations were carried out to determine the relationship between thermal and mechanical characteristics and irradiation dose. The test results were quantitatively presented, and it was found that the irradiated PUF has potential for application in industrial structures. 相似文献
994.
Daniel P. Sweat Xiang Yu Myungwoong Kim Padma Gopalan 《Journal of polymer science. Part A, Polymer chemistry》2014,52(10):1458-1468
Living anionic polymerization of an acetal protected 4‐hydroxystyrene monomer, (4‐(2‐tetrahydropyranyloxy)styrene) (OTHPSt), and the chain extension of the poly(OTHPSt) anion with a variety of monomers including styrene, 4‐tert‐butylstyrene, methacryloyl polyhedral oligomeric silsesquioxane (MAPOSS) and hexamethylcyclotrisiloxane is demonstrated. The P(OTHPSt) homopolymer has a glass transition temperature well above room temperature, which facilitates handling and purification of the protected poly(4‐hydroxystyrene) (PHS). The resulting diblock copolymers have narrow dispersities <1.05. Chemoselective mild deprotection conditions for the P(OTHPSt) block were identified to prevent simultaneous degradation of the MAPOSS or dimethylsiloxane (DMS) block, thus allowing for the first reported synthesis of P(HS‐b‐DMS) and P(HS‐b‐MAPOSS). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1458–1468 相似文献
995.
T. Kim 《Russian Journal of Mathematical Physics》2012,19(2):193-196
In the paper, we derive an analog of the Lebesgue-Radon-Nikodym theorem with respect to fermionic p-adic invariant measure on ? p . 相似文献
996.
997.
Journal of the Korean Physical Society - In intensity-modulated radiosurgery (IMRS) treatment, radiation delivery techniques require the ability to accurately verify complex three-dimensional (3D)... 相似文献
998.
N-substituted anilines react with triethanolamine in the presence of a catalytic amount of a homogeneous ruthenium catalyst to give the corresponding 1-substituted indoles in good yields. 相似文献
999.
Bert C. Lynn Jesus V. Mallén Servando Muñoz Minsook Kim George W. Gokel 《Supramolecular chemistry》2013,25(3-4):195-197
Abstract Bola-amphiphiles having two aza-18-crown-6 ether rings attached by a covalent spacer (O—O) and an analogous tris (macrocycle) (O—O—O) have been prepared and their cation complexation behavior has been assessed by fast atom bombardment and collisionally activated dissociation tandem mass spectrometry; the key finding is that two cations may simultaneously be complexed by a two- or three-crown system and that this complexation may also involve an anion. 相似文献
1000.
Dr. Sumith A. Kularatne Vishal Deshmukh Dr. Marco Gymnopoulos Dr. Sandra L. Biroc Dr. Jinming Xia Shailaja Srinagesh Dr. Ying Sun Dr. Ning Zou Dr. Mark Shimazu Dr. Jason Pinkstaff Dr. Semsi Ensari Nick Knudsen Anthony Manibusan Dr. Jun Y. Axup Dr. Chan Hyuk Kim Prof. Vaughn V. Smider Dr. Tsotne Javahishvili Prof.Dr. Peter G. Schultz 《Angewandte Chemie (International ed. in English)》2013,52(46):12101-12104