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491.
Anomalous magnetic properties of MnO nanoclusters 总被引:3,自引:0,他引:3
Lee GH Huh SH Jeong JW Choi BJ Kim SH Ri HC 《Journal of the American Chemical Society》2002,124(41):12094-12095
In this communication, we experimentally report, for the first time, that the MnO nanoclusters with cluster diameters of 5-10 nm show a ferromagnetic behavior with a phase transition from ferromagnetic to paramagnetic phases at 27 K even though their bulk phase is antiferromagnetic. We observed large coercivities up to 9500 Oe and a large remanence of 1.72 emu/g at 2 K, which are typically observed values for ferromagnetic materials. Although it is not clear, this abnormal ferromagnetic behavior of MnO nanoclusters may arise from cluster size effects. 相似文献
492.
J.H. Ha J.C. Kim C.S. Lee J.Y. Huh C.-B. Moon Y. Gono S. Mitarai T. Morikawa M. Shibata H. Watanabe M. Miyake E. Komatsu A. Odahara E. Ideguchi X.H. Zhou 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):247-248
High-spin states of odd-odd 168Lu were observed up to 18ħ for the first time using the 159Tb(13C, 4nγ)168Lu reaction at E
13C= 58.5 MeV. γ-γ coincidence, E
γ singles, excitation function, and the DCO ratios were measured. Two rotational bands with signature splitting were populated,
among which the lower-energy band is identified as π 7/2+[404] ⊗ν 5/2+[642] in view of alignment and energy systematics.
Received: 27 October 1997 相似文献
493.
Let X/Fp be an Artin–Schreier curve defined by the affine equation y
p
–y=f(x) where f(x)Fp[x] is monic of degree d. In this paper we develop a method for estimating the first slope of the Newton polygon of X. Denote this first slope by NP1(X/Fp). We use our method to prove that if p>d2 then NP1(X/Fp)(p–1)/d/(p–1). If p>2d4, we give a sufficient condition for the equality to hold. 相似文献
494.
495.
June Trop Zuckerman 《School science and mathematics》1994,94(5):226-234
This study focused on the knowledge of six outstanding science students who solved an osmosis problem meaningfully. That is, they used appropriate and substantially accurate conceptual knowledge to generate an answer. Three generated a correct answer; three, an incorrect answer. This paper identifies both the accurate and inaccurate conceptions about osmosis of each correct and incorrect solver. The investigation consisted of a presolving clinical interview, think-aloud solving of the problem, and retrospective report of the solving. Of the 12 accurate conceptions identified here, two were especially important in enabling these solvers to generate a correct answer. Of the 8 inaccurate conceptions, either of 2 blocked a correct answer. Four, however, accompanied (and could therefore be concealed by) a correct answer. Teachers could use this information to make a meaningful solving of this problem accessible to more students and to identify more effectively students' inaccurate conceptions about osmosis. 相似文献
496.
Hyungjin Huh 《Letters in Mathematical Physics》2007,79(1):75-94
We study initial value problems of the Chern–Simons–Dirac equations. With the Lorentz gauge condition they are formulated
in the second-order hyperbolic equations. Under the Coulomb gauge condition Dirac equation is coupled with the elliptic equations
which show some smoothing properties of the gauge field. With the temporal gauge condition divergence-curl decomposition and
elliptic estimates will be used.
JSPS Research Follow supported by JSPS Grant-in-Aid 相似文献
497.
A scalable synthetic route towards a chiral 2,2,6-trisubstituted chiral morpholine, which is a known opioid antagonist, was developed. The synthetic route involves incorporating an aryl group via Suzuki-Miyaura coupling and stereoselective hydroalkoxylation catalyzed by trifluoromethanesulfonic acid. Late stage incorporation of both the aryl and N-alkyl groups make this route suitable for further SAR studies on this molecule. 相似文献
498.
Daniel N. Huh Sierra R. Ciccone Samuel Bekoe Saswata Roy Joseph W. Ziller Filipp Furche William J. Evans 《Angewandte Chemie (International ed. in English)》2020,59(37):16141-16146
Lanthanide triflates have been used to incorporate NdIII and SmIII ions into the 2.2.2‐cryptand ligand (crypt) to explore their reductive chemistry. The Ln(OTf)3 complexes (Ln=Nd, Sm; OTf=SO3CF3) react with crypt in THF to form the THF‐soluble complexes [LnIII(crypt)(OTf)2][OTf] with two triflates bound to the metal encapsulated in the crypt. Reduction of these LnIII‐in‐crypt complexes using KC8 in THF forms the neutral LnII‐in‐crypt triflate complexes [LnII(crypt)(OTf)2]. DFT calculations on [NdII(crypt)]2+], the first NdII cryptand complex, assign a 4f4 electron configuration to this ion. 相似文献
499.
Nagendra Kalva Saji Uthaman Rimesh Augustine Su Hyeon Jeon Kang Moo Huh In‐Kyu Park Il Kim 《Macromolecular bioscience》2020,20(8)
Photo/pH dual‐responsive amphiphilic diblock copolymers with alkyne functionalized pendant o‐nitrobenzyl ester group are synthesized using poly(ethylene glycol) as a macroinitiator. The pendant alkynes are functionalized as aldehyde groups by the azide‐alkyne Huisgen cycloaddition. The anticancer drug doxorubicin (DOX) molecules are then covalently conjugated through acid‐sensitive Schiff‐base linkage. The resultant prodrug copolymers self‐assemble into nanomicelles in aqueous solution. The prodrug nanomicelles have a well‐defined morphology with an average size of 20–40 nm. The dual‐stimuli are applied individually or simultaneously to study the release behavior of DOX. Under UV light irradiation, nanomicelles are disassembled due to the ONB ester photocleavage. The light‐controlled DOX release behavior is demonstrated using fluorescence spectroscopy. Due to the pH‐sensitive imine linkage the DOX molecules are released rapidly from the nanomicelles at the acidic pH of 5.0, whereas only minimal amount of DOX molecules is released at the pH of 7.4. The DOX release rate is tunable by applying the dual‐stimuli simultaneously. In vitro studies against colon cancer cells demonstrate that the nanomicelles show the efficient cellular uptake and the intracellular DOX release, indicating that the newly designed copolymers with dual‐stimuli‐response have significant potential applications as a smart nanomedicine against cancer. 相似文献
500.
We investigate the reflexive sheaves on ${\mathbb{P}^3}$ spanned in codimension 2 with very low first Chern class c 1. We also give the sufficient and necessary conditions on numeric data of such sheaves for indecomposabiity. As a by-product we obtain that every reflexive sheaf on ${\mathbb{P}^3}$ spanned in codimension 2 with c 1 = 2 is spanned. 相似文献