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排序方式: 共有119条查询结果,搜索用时 31 毫秒
1.
2.
Ulrich Mayerhofer T. von Egidy J. Jolie H. G. Börner G. Colvin S. Judge B. Krusche S. J. Robinson K. Schreckenbach S. Brant V. Paar 《Zeitschrift für Physik A Hadrons and Nuclei》1991,341(1):1-8
Gamma rays of199Au obtained after double neutron capture in197Au were measured at the ILL high flux reactor. A level scheme up to 1770 keV excitation energy is established. The result is compared with IBFM and Boson-Fermion-Symmetry calculations. 相似文献
3.
H. Seyfarth H. H. Güven B. Kardon W. D. Lauppev G. Lhersonneau K. Sistemich S. Brant N. Kaffrell P. Maier-Komor H. K. Vonach V. Paar D. Vorkapić R. A. Meyer 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(2):269-278
The properties of the triplet of low-lying states in101Mo have been studied through spectroscopy of theγ radiation following thermal neutron capture in100Mo and β? decay of101Nb and through a measurement of the proton angular distributions in the100Mo(d,p) reaction with 14 MeV deuteron energy. The half-lives of the 13.5 keV state and the 57.0 keV 5/2+ state have been measured as 226(7) and 133(7)ns, respectively. These values and the quadrupole/dipole mixing ratios of the 13.5 keV and 43.5 keV transitions yield spin and parity 3/2+ for the 13.5 keV level. The E2 components in the 13.5 (3/2+ →1/2+) and 43.5 keV (5/2+→3/2+) transitions are ≦ 8·10?4 and 54(9)%, respectively. The possibility of an additional state near to the 57.0 keV level is discussed. IBFM/PTQM calculations, taking into consideration the transitional character of the100Mo boson core, account for the electromagnetic-transition and transfer-reaction pattern of the triplet of states. 相似文献
4.
The hyperfine structure of 161Dy and 163Dy for five transitions hasbeen measured with a tunable dye laser and a thermal velocity atomic beam. Values for the magnetic dipole and electric quadrupole coupling constants have been determined for the relevant excited states. The hyperfine anomaly parameters, Δ, which are extracted are interpreted in terms of available atomic wave functions. 相似文献
5.
A donor-acceptor compound based on N,N,N',N'-tetramethyl-p-phenylene-diamine and 1,2,4,5-tetracyanobenzene (TMPD:TCNB) has been synthesized. The crystal structure of the black 1:1 complex formed between TMPD and TCNB has been determined by single crystal X-ray diffraction at room temperature. The compound crystallizes in the triclinic space group P-1 with cell dimensions: a = 7.4986(15) ?, b =7.6772(11) ?, c = 8.0764(15) ?, alpha = 78.822(12) degrees, beta = 83.3779(19) degrees, gamma = 86.289(17) degrees .TMPD and TCNB molecules are stacked alternately in infinite columns along the a-axis. The structure does not seem to show the usual pi-pi interaction between the two aromatic rings, but indicates an n-pi interaction localized between the nitrogen atoms of the donor and the cyano groups of the acceptor. 相似文献
6.
Brant Cage James Halley McNeely Kim Davis Anthony J. Mihovilovich Bhavani Gopalakrishnan Bonnie Haferkamp Tijana Rajh Bernard D. Santarsiero 《Polyhedron》2010
A series of Cr(III) dimers were synthesized from a parent compound [Cr2(μ-oxo)2(μ1,2-C4O4)2(H2O)4]·2H2O (I) by ligand substitution. The compounds have been analyzed using variable frequency EPR (9–110 GHz) and magnetic susceptibility as a function of field (0–9 T) and temperature (1.9–300 K) to obtain their electronic g-values, exchange energies, and zero-field parameters. The parent compound exhibits a broad maximum around 34 K characteristic of a dimer with antiferromagnetic coupling that fit the Van Vleck susceptibility model well. It was found that the maxima could be tuned from 34 to 80 K by ligand substitution of the waters. Each compound possesses a characteristic color spanning the range of teal to pink. The g-value of each compound was found to be ∼1.98 using spectral simulation. The DMSO derivative is water soluble and has a high LC50 for PC3 cancer cells, suggesting its use as a magnetic resonance imaging agent. X-ray crystal structure of the DMSO derivative [Cr2(μ-oxo)2(μ1,2-C4O4)2(C2H6SO)4]·2H2O (II) revealed that the DMSO ligands are equatorial, and the squarate groups bridge the two chromiums. This is in contrast to the previously proposed structure of the parent compound where the water ligands were axial and the equatorial squarate groups did not bridge the chromiums. These compounds are interesting because of their ease of synthesis, and their wide range of magnetic behavior. The compounds are good probes into antiferromagnetic dimer exchange by controlling the ligand field surrounding the superexchange pathway present in the molecule. 相似文献
7.
Jie XiaoN. Lozova Ya.B. Losovyj D. WootenI. Ketsman M.W. SwinneyJ. Petrosky J. McCloryYa.V. Burak V.T. AdamivA.T. Brant P.A. Dowben 《Applied Surface Science》2011,257(8):3399-3403
We have compared the photovoltaic charging of the (1 0 0) surface termination for Cu doped and undoped Li2B4O7. While the surface charging at the (1 0 0) surface of Li2B4O7 is significantly greater than observed at (1 1 0) surface, the Cu doping plays a role in reducing the surface photovoltage effects. With Cu doping of Li2B4O7, the surface photovoltaic charging is much diminished at the (1 0 0) surface. The density of states observed with combined photoemission and inverse photoemission remains similar to that observed for the undoped material, except in the vicinity of the conduction band edge. 相似文献
8.
D. Sohler Zs. Dombrádi S. Brant J. Cederkäll M. Lipoglavšek M. Palacz V. Paar J. Persson A. Atac̣ C. Fahlander H. Grawe A. Johnson A. Kerek W. Klamra J. Kownacki A. Likar L. O. Norlin J. Nyberg R. Schubart D. Seweryniak G. de Angelis P. Bednarczyk D. Foltescu M. Fayez-Hassan D. Jerrestam S. Juutinen E. Mäkelä B. M. Nyakó M. de Poli H. A. Roth T. Shizuma Ö. Skeppstedt G. Sletten S. Törmänen 《Zeitschrift für Physik A Hadrons and Nuclei》1997,357(3):239-240
Excited states of 65Ge were populated via the 12C + 58Ni (261 MeV) reaction using the NORDBALL detector array equipped with charged-particle and neutron detector systems for reaction channel separation. On the basis of γγ-coincidence relations and angular distribution ratios a significantly extended level scheme was constructed up to E x = 9 MeV and J π = (33/2?). The low-energy states of the nucleus are discussed in the framework of the interacting boson-fermion model. 相似文献
9.
The use of commercially available (SIPr)Pd(cinnamyl)Cl (SIPr = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene) as a precatalyst for the anaerobic oxidation of secondary alcohols is described. The use of this complex allows for a drastic reduction in the reaction times and catalyst loading when compared to the unsaturated counterpart. This catalytic system is compatible with the use of microwave dielectric heating, decreasing even further catalyst loading and reaction times. Domino Pd-catalyzed oxidation-arylation reactions of secondary alcohols are also presented. 相似文献
10.
Age changes in pure-tone hearing thresholds in a longitudinal study of normal human aging 总被引:5,自引:0,他引:5
Hearing thresholds were obtained on 813 adult males (20-95 years) measured at 11 frequencies ranging from 0.125-8 kHz from pure-tone audiograms collected over a 20-year period from 1968 to 1987. Audiograms taken at two to six different ages spanning a maximum observation period of 15 years were obtained for each male belonging to one of seven different age groups (20,30,...,80 years) based on the age of initial observation. The males were participants in the Baltimore Longitudinal study of Aging (BLSA), a multidisciplinary community-based study of normal human aging. Changes in hearing thresholds occurred in all age groups during the 15-year follow-up period. For example, at 0.5 and 8 kHz for combined left and right ears there was an average longitudinal loss of 5.7-7.6 and 5.1-21.1 dB, respectively, for 20-year-olds, 10.0-12.7 and 35.2-53.0 dB for 50-year-olds, and 22.9-48.5 and 69.0-84.5 dB for 80-year-olds. As in results from previous cross-sectional studies, hearing loss in the males 70 years and older is greatest at the highest frequencies. The rate of change for these older males is faster in the speech-range frequencies 0.5-2 kHz than in the higher frequencies, since their hearing has already diminished at the high frequencies. 相似文献