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71.
Tin(II) chloride inserts into the ironcarbon σ-bond in MeFe(CO)2Cp (Cp = cyclopentadienyl), in refluxing methanol or THF, to give MeClSnFe(CO)2- Cp and traces of Cl3SnFe(CO)2Cp, but, with EtFe(CO)2Cp, a mixture of the insertion product, Cl3SnFe(CO)2Cp, and Cl2Sn[Fe(CO)2Cp]2 is formed. Insertion of tin(II) chloride was not observed for MeMo(CO)3Cp and MeMn(CO)5; in these reactions, and in those between tin(II)_bromide and MeFe(CO)2Cp, EtFe(CO)2Cp and Memo(CO)3Cp, mixtures of halo—metal carbonyls and halotin—metal carbonyls result.  相似文献   
72.
The energy levels of 182Hg have been identified for the first time through comparison of in-beam studies of the reactions 156,154Gd(32S, 4n)184,182Hg and γ-X-ray coincidences. Levels up to 12+ in 182Hg were established from γ-γ coincidences and singles measurements. The data establish that the ground state shape is near spherical, and that the ground band is crossed by a well-deformed band at 4+. In contrast to IBA model predictions that the deformed band will rise in energy in 182Hg compared to 184Hg, the energies of the deformed levels in 182Hg continue to drop.  相似文献   
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75.
Electron spin resonance has been observed in high purity single crystals of K2Pt(CN)4Br0.3·3.2H2O, (KCP), in the temperature range of 4.22–80 K. Two types of paramagnetic species are found to dominate the spectrum. One of these is an inhomogeneously broadened line showing no resolved hyperfine splitting and having g = 1.946 ± 0.003 and g⊥ = 2.340 ± 0.003. The second paramagnet is identified as a Cu2+ impurity center with g = 2.231 ± 0.003, g⊥ = 2.079 ± 0.002 and hyperfine tensor A = 467 MHz, A = 70 MHz.  相似文献   
76.
We report evidence for B(0) --> D(0)D(-) and the first observation of the decay modes B(-) --> D(0)D(-) and B(-) --> D(0)D(*-) based on a sample of 152 x 10(6) BB events collected by the Belle detector at KEKB. The branching fractions for B(0) --> D(+) D(-), B--->D(0)D(-), and B--> D(0)D(*-) are found to be (1.91 +/- 0.51 +/- 0.30) x10(-4), (4.83 +/- 0.78 +/- 0.58) x 10(-4), and (4.57 +/- 0.71 +/- 0.56) x 10(-4), respectively. Charge asymmetries in the B---> D(0)D(-) and B(-) --> D(0)D(*-) channels are consistent with zero.  相似文献   
77.
We present a measurement of CP-violation parameters in the B0 --> K(s)0K(s)0K(s)0 decay based on a sample of 275 x 10(6) BB pairs collected at the upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in the decay B0 --> K(s)0K(s)0K(s)0, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters are obtained from the asymmetry in the distributions of the proper-time interval between the two B decays: S = +1.26 +/- 0.68(stat) +/- 0.20(syst) and [symbol: see text] = +0.54 +/- 0.34(stat) +/- 0.09(syst).  相似文献   
78.
We report the observation of a near-threshold enhancement in the omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from a 253 fb(-1) data sample that contains 275 x 10(6) BB pairs that were collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. The statistical significance of the omegaJ/psi mass enhancement is estimated to be greater than 8sigma.  相似文献   
79.
Heat capacity measurements have been made down to 5 mK for 3He fluid films adsorbed in one-dimensional (1D) nanometer-scale pores, 28 A in diameter, preplated with 4He of 1.47 atomic layers. At low 3He density, the heat capacity shows a density-dependent, Schottky-like peak near 150 mK asymptoting to the value corresponding to a 2D Boltzmann gas at high temperatures. The peak behavior is attributed to the crossover from a 2D gas to a 1D state at low temperatures. The degenerate state of the 1D 3He fluid is indicated by a predominantly linear temperature dependence below about 30 mK.  相似文献   
80.
We have searched for mixing in the D(0)-D (0) system by measuring the decay-time distribution of D(0) --> K(+) pi(-) decays. The analysis uses 90 fb(-1) of data collected by the Belle detector at the KEKB e(+) e(-) collider. We fit the decay-time distribution for the mixing parameters x' and y' and also for the parameter R(D), which is the ratio of the rate for the doubly-Cabibbo-suppressed decay D(0)--> K+ pi(-) to that for the Cabibbo-favored decay D(0)--> K-pi(+). We do these fits both assuming CP conservation and allowing for CP violation. We use a frequentist method to obtain a 95% C.L. region in the x'(2) - y' plane. Assuming no mixing, we measure R(D) = (0.381 +/- 0.017(+0.008)(-0.016))%.  相似文献   
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