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61.
Mohd Yusuf Khan Xiangxiong Chen Seung Woo Lee Seok Kyun Noh 《Macromolecular rapid communications》2013,34(15):1225-1230
Atom transfer radical polymerization (ATRP) catalyzed by high oxidation state metal salts of FeX3 is developed for the first time in the absence of both external initiator and reducing agent. Methyl methacrylate (MMA) and styrene are polymerized successfully using FeX3/Phosphorous ligands with well‐controlled molecular weight distributions (=1.5). The molecular weight of the polymers increases with monomer consumption with the progress of time and the polymerization behaviors show a decent ATRP trend. Activators and initiators are suggested to generate in situ by the addition reaction of MMA and one equivalent of FeX3. The PMMA synthesized from without‐initiator system is characterized by 1H, 13C and DEPT (distortionless enhancement by polarization transfer nuclear magnetic resonance) nuclear magnetic resonance spectroscopy. Chain extension and copolymerization experiments prove the livingness of the obtained polymer.
62.
Sunsook Noh 《代数通讯》2013,41(2):613-624
Let υ be a prime divisor of a 2-dimensional regular local ring (R m) with algebraically closed residue field k. Zariski showed that a prime divisor υ of R is uniquely associated to a simple m-primary integrally closed ideal I of R, there exist finitely many simple υ-ideals including I, and all the other υ-ideals can be uniquely factored into products of simple υ-ideals. It is known that such an m-primary ideal I of R can be minimally generated by o(I) + 1 elements.Given a simple integrally closed ideal I of order one with arbitrary rank and its associated prime divisor υ, we find minimal generating sets of all the simple υ-ideals and describe factorizations of all the composite υ-ideals in terms of power products of simple υideals as explicitly as possible. 相似文献
63.
Moon SJ Choi WS Kim SJ Lee YS Khalifah PG Mandrus D Noh TW 《Physical review letters》2008,100(11):116404
We investigated the electronic response of the quasi-two-dimensional spin gap compound La4Ru2O10 using optical spectroscopy. We observed the drastic changes in the optical spectra as the temperature decreased, resulting in anisotropy in the electronic structure of the spin-singlet ground state. Using the orbital-dependent hopping analysis, we found that orbital ordering plays a crucial role in forming the spin gap state in the non-one-dimensional material. 相似文献
64.
Wu W Kiryukhin V Noh HJ Ko KT Park JH Ratcliff W Sharma PA Harrison N Choi YJ Horibe Y Lee S Park S Yi HT Zhang CL Cheong SW 《Physical review letters》2008,101(13):137203
We have studied quasi-two-dimensional multiferroic LuFe2O4 with strong charge-spin-lattice coupling, in which low-temperature coercivity approaches an extraordinary value of 9 T in single crystals. The enhancement of the coercivity is connected to the collective freezing of nanoscale pancakelike ferrimagnetic domains with large uniaxial magnetic anisotropy ("Ising pancakes"). Our results suggest that collective freezing in low-dimensional magnets with large uniaxial anisotropy provides an effective mechanism to achieve enhanced coercivity. This observation may help identify novel approaches for synthesis of magnets with enhanced properties. 相似文献
65.
A new class of static plane symmetric solution of Einstein field equation generated by a perfect fluid source is put forward. A special family of this new solution is investigated in detail. The constraints on the parameters by different energy conditions are studied. The classical stability of this solution is discussed. The junction conditions matching to Minkowski metric and Taub metric are analyzed respectively. 相似文献
66.
67.
Seong-Wook Kim Hyeonjung Jung Dr. Mahmut Sait Okyay Dr. Hyuk-Jun Noh Sein Chung Young Hyun Kim Jong-Pil Jeon Prof. Dr. Bryan M. Wong Prof. Dr. Kilwon Cho Dr. Jeong-Min Seo Prof. Dr. Jung-Woo Yoo Prof. Dr. Jong-Beom Baek 《Angewandte Chemie (International ed. in English)》2023,62(42):e202310560
The development of covalent organic frameworks (COFs) with efficient charge transport is of immense interest for applications in optoelectronic devices. To enhance COF charge transport properties, electroactive building blocks and dopants can be used to induce extended conduction channels. However, understanding their intricate interplay remains challenging. We designed and synthesized a tailor-made COF structure with electroactive hexaazatriphenylene (HAT) core units and planar dioxin (D) linkages, denoted as HD-COF. With the support of theoretical calculations, we found that the HAT units in the HD-COF induce strong, eclipsed π–π stacking. The unique stacking of HAT units and the weak in-plane conjugation of dioxin linkages leads to efficient anisotropic charge transport. We fabricated HD-COF films to minimize the grain boundary effect of bulk COFs, which resulted in enhanced conductivity. As a result, the HD-COF films showed an electrical conductivity as high as 1.25 S cm−1 after doping with tris(4-bromophenyl)ammoniumyl hexachloroantimonate. 相似文献
68.
Kim Na Young Jung Jae-Sun Lee Jae Suk Yang Eun Hyeok Hong Gi Hoon Lim Sung Soo Noh Young Su Hodala Janardhan L. Lee Kwan Young Moon Dong Ju 《Research on Chemical Intermediates》2016,42(1):319-334
Research on Chemical Intermediates - In this work, we synthesized a Co-based catalyst supported on modified SBA-15 to obtain the uniform particle size of active metal and selective products with... 相似文献
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