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91.
M. Hausmann J. Stadlmann F. Attallah K. Beckert P. Beller F. Bosch H. Eickhoff M. Falch B. Franczak B. Franzke H. Geissel Th. Kerscher O. Klepper H.-J. Kluge C. Kozhuharov Yu.A. Litvinov K.E.G. Löbner G. Münzenberg N. Nankov F. Nolden Yu.N. Novikov T. Ohtsubo T. Radon H. Schatz C. Scheidenberger M. Steck Z. Sun H. Weick H. Wollnik 《Hyperfine Interactions》2001,132(1-4):289-295
A novel method for mass measurements of short-lived exotic nuclides is presented. Exotic nuclides were produced and separated
in flight at relativistic energies with the fragment separator (FRS) and were injected into the experimental storage ring
(ESR). Operating the ESR in the isochronous mode we performed mass measurements of neutron deficient fragments of 84Kr with half-lives larger than 50 ms. However, this experimental technique is applicable in a half-life range down to a few
μs. A mass resolving power of 110000 (FWHM) has been achieved. Results are presented for the masses of 68As, 70,71Se and 73Br.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
92.
Holger Schwierz Fritz Vögtle 《Journal of inclusion phenomena and macrocyclic chemistry》2000,37(1-4):309-329
New nanometre-sized macrocyclictosylaza[3n]paracyclophanes have been synthesized bymeans of an iterative synthetic strategy using linearbuilding blocks with up to four benzene units. Theformation of the open-chain difunctionalized linearmolecules was achieved by a three step reactionsequence including nucleophilic substitution andtransformation of the terminal ester groups to thecorresponding dialcohol and dibromide. The finalintermolecular macrocyclizations were carried out byreaction of open chained dibromides andbis(tosylamides) to obtain nanosize macrocyclicoligotosylamides in 31–50% yield. Highly symmetricaltosylaza[3n]paracyclophanes containing up to sevenbenzene units and up to 49 ring members (n = 5–7) wereobtained. Also described is the preparation of30–90-membered paracyclophanes containing biphenyl orterphenyl units. 相似文献
93.
Zhanmin Zhu 《数学研究》2021,54(4):451-459
Let $I$ be an ideal of a ring $R$. We call $R$ weakly $I$-semiregular if $R$/$I$ is a von Neumann regular ring. This definition generalizes $I$-semiregular rings. We give a series of characterizations and properties of this class of rings. Moreover, we also give some properties of $I$-semiregular rings. 相似文献
94.
95.
介观金属双环系统中的持续电流和量子能谱 总被引:7,自引:1,他引:7
崔元顺 《原子与分子物理学报》2006,23(3):527-531
基于电荷的不连续性,对处于外磁场中的介观双环系统进行量子化.假设系统在电荷表象中具有变换的对称性,通过求解电流和Hamilton算符的本征值方程,给出介观金属环互感系统中的量子电流和能谱关系;分析和研究了介观金属环中量子电流和能谱的性质.结果表明,持续电流和量子能谱不仅与外磁场、介观双环参数有关,而且还明显地依赖于电荷的量子化性质. 相似文献
96.
主要证明了:(i)假设R是右广义半正则右ACS-环,若J(R)∩I=J(I)对于R的任意右理想I都成立,则J(R)=Z(RR);(ii)如果R是右AP-内射环且R的每个奇异单右R-模是GP-内射,则对于R的任意右理想I都有J(R)∩I=J(I). 相似文献
97.
Salicylaldehyde thiosemicarbazone (H2saltsc) reacts with [M(PPh3)3X2] (M = Ru, Os; X = Cl, Br) to afford complexes of type [M(PPh3)2(Hsaltsc)2], in which the salicylaldehyde thiosemicarbazone ligand is coordinated to the metal as a bidentate N,S-donor forming a four-membered
chelate ring. Reaction of benzaldehyde thiosemicarbazones (Hbztsc-R) with [M(PPh3)3X2] also affords complexes of similar type, viz. [M(PPh3)2(bztsc-R)2], in which the benzaldehyde thiosemicarbazones have also been found to coordinate the metal as a bidentate N,S-donor forming
a four-membered chelate ring as before. Reaction of the Hbztsc-R ligands has also been carried out with [M(bpy)2X2] (M = Ru, Os; X = Cl, Br), which has afforded complexes of type [M(bpy)2(bztsc-R)]+, which have been isolated as perchlorate salts. Coordination mode of bztsc-R has been found to be the same as before. Structure
of the Hbztsc-OMe ligand has been determined and some molecular modelling studies have been carried out determine the reason
for the observed mode of coordination. Reaction of acetone thiosemicarbazone (Hactsc) has then been carried out with [M(bpy)2X2] to afford the [M(bpy)2(actsc)]ClO4 complexes, in which the actsc ligand coordinates the metal as a bidentate N,S-donorformingafive-membered chelate ring. Reaction
of H2saltsc has been carried out with [Ru(bpy)2Cl2] to prepare the [Ru(bpy)2(Hsaltsc)]ClO4 complex, which has then been reacted with one equivalent of nickel perchlorate to afford an octanuclear complex of type [Ru(bpy)2(saltsc-H)4Ni4](ClO4)4. 相似文献
98.
Franco Carillo Giorgio Biasiol Diego Frustaglia Francesco Giazotto Lucia Sorba Fabio Beltram 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):53
Electron-phase modulation in magnetic and electric fields will be presented in In0.75Ga0.25As Aharonov–Bohm (AB) rings. The zero Schottky barrier of this material made it possible to nanofabricate devices with radii down to below 200 nm without carrier depletion. We shall present a fabrication scheme based on wet and dry etching that yielded excellent reproducibility, very high contrast of the oscillations and good electrical gating. The operation of these structures is compatible with closed-cycle refrigeration and suggests that this process can yield coherent electronic circuits that do not require cryogenic liquids. The InGaAs/AlInAs heterostructure was grown by MBE on a GaAs substrate [F. Capotondi, G. Biasiol, D. Ercolani, V. Grillo, E. Carlino, F. Romanato, L. Sorba, Thin Solid Films 484 (2005) 400], and in light of the large effective g-factor and the absence of the Schottky barrier is a material system of interest for the investigation of spin-related effects [W. Desrat, F. Giazotto, V. Pellegrini, F. Beltram, F. Capotondi, G. Biasiol, L. Sorba, D.K. Maude, Phys. Rev. B 69 (2004) 245324; W. Desrat, F. Giazotto, V. Pellegrini, M. Governale, F. Beltram, F. Capotondi, G. Biasiol, L. Sorba, Phys. Rev. B 71 (2005) 153314; J. Nitta, T. Akazaki, H. Takayanagi, T. Enoki, Phys. Rev. Lett. 78 (1997) 1335] and the realization of hybrid superconductor/semiconductor devices [Th. Schäpers, A. Kaluza, K. Neurohr, J. Malindretos, G. Crecelius, A. van der Hart, H. Hardtdegen, H. Lüth, Appl. Phys. Lett. 71 (1997) 3575]. 相似文献
99.
Luis G.G.V. Dias da Silva Sergio E. Ulloa Tigran V. Shahbazyan 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):37
We study the interplay between impurity scattering and Coulomb interaction effects in the absorption spectrum of neutral bound magnetoexcitons confined in quantum-ring structures. Impurity scattering breaks the rotational symmetry of the ring system, introducing characteristic features in the optical emission. Signatures of the optical Aharonov–Bohm effect are still present for weak scattering and strong Coulomb screening. Furthermore, an impurity-induced modulation of the absorption strength is present even for a strong impurity potential and low screening. This behavior is likely responsible of recent experimental observations in quantum-ring structures. 相似文献
100.
Kazuya Kato 《K-Theory》2005,34(2):99-140
We compute K1 of completed group rings of some two dimensional p-adic Lie groups.
Dedicated to Professor Spencer Bloch on his sixtieth birthday 相似文献