β-delayed neutron decay of drip line nuclei 11Li and 14Be

Experimental studies of β-decay measurements of the neutron drip line nuclei ¹¹Li and ¹⁴Be are presented. β- decay schemes of these nuclei are determined by measuring β-rays, delayed neutrons and γ-rays in triple coincidence. The decay schemes of both ¹¹Li and ¹⁴Be associated with single neutron emission are unambiguously determined. New levels in their daughter nuclei, ¹¹Be and ¹⁴B, are found. In addition, the deduced level scheme of 14B indicates the lowering of 2s _1/2 single neutron orbital with respect to 1p _1/2 orbital in the N=9 isotones. Such behavior is known to exist in N=7.     

Nuclear resonance measurements of CePd2Ga3

CePd₂Ga₃, a Kondo lattice exhibiting ferromagnetic order below T _C = 6.3 K, has been studied using Ga NMR technique. Measurements of the magnetic susceptibility on an oriented sample proved the strong anisotropy of this quantity, whose major component is in the basal plane. From the analysis of NMR spectra of differently oriented samples, the quadrupole parameters and the temperature-dependent anisotropic Knight-shift have been determined. While the anisotropy of the susceptibility can sufficiently account for the axial anisotropy of the ⁷¹Ga Knight shift, the in-plane anisotropy of the shift points towards dipolar effects enhanced by hybridization of the Ce-4f and Ga-s electrons.     

Structures and decay of deep-hole states in light nuclei populated by the (p, 2p 2p) reactions

Decay particles from the s-hole states in ¹¹B and ¹⁵N have been measured in coincidence with the quasifree ¹²C(p, 2p) and ¹⁶O(p, 2p) reactions at E _p =392 MeV. Triton decay is found to be dominant for the ¹¹B(s-hole) state and also found to be larger than α decay for the ¹⁵N(s-hole) state despite its smaller Q value compared to α decay. Measured decay branching ratios are discussed in comparison with the results of statistical-model, SU(3)-model, and shell-model calculations. The energy spectra around the s-hole states in both ¹¹B and ¹⁵N exhibit some bumplike structures, which can be qualitatively explained by recent shell-model calculations for both nuclei.     

Proton nuclear magnetic resonance spectra of brain tumors

Proton nuclear magnetic resonance (NMR) spectra were successfully measured in human brain tumor tissues and experimental rat brain tumors. The investigation was performed on clinical materials which consisted of tissue from one normal brain and 36 brain tumors. Normal rat brain tissue and rat glioma implanted in the brain were also analysed. NMR measurements were carried out at the resonance frequency of 99.54 MHz. The proton NMR spectrum of the normal brain consisted of one broad component and eight superimposed sharp peaks. The sharp peaks obtained from the brain tumors varied from those of the normal brain. A decrease in the signal intensity from N-acetyl aspartate was the most common finding in all tumors. Spectral patterns were similar within the same histological types, but varied among the different types. Therefore, ¹H-NMR spectra might indicate the metabolism characteristic of each tumor type which would be invaluable for clinical differential dagnosis of brain tumors.     

Global identifiability for an inverse problem for the Schrödinger equation in a magnetic field

Partially supported by NSF Grant DMS-9123742     

Purealin,a novel enzyme activator from the Okinawan marine sponge Psammaplysilla purea

Purealin , a novel secondary metabolite, which modurates enzymic reactions of ATPases, has been isolated from the okinawan marine sponge $\text{Psammaplysilla}$$\text{purea}$ and the structure has been determined by the ¹H-¹H homonuclear and ¹H-¹³C heteronuclear NMR chemical shift correlations and CD spectra.     

Direct resolution of enantiomers by liquid chromatography with the novel chiral stationary phase derived from (R,R)-tartramide

The synthesis of the novel chiral stationary phase (CSP) derived from (R,R)-tartramide and direct resolution of a series of β-hydroxycarboxylic acid derivatives on this CSP are described.