Abstract: Spatial localization techniques are necessary for in vivo NMR spectroscopy involving heterogeneous organisms. Localization by surface coil NMR detection alone is generally inadequate for deep-lying organs due to contaminating signals from intervening surface tissues. However, localization to preselected planar volumes can be accomplished using a single selective excitation pulse in the presence of a pulsed magnetic field gradient, yielding depth-resolved surface coil spectra (DRESS). Within selected planes, DRESS are spatially restricted by the surface coil sensitivity profiles to disk-shaped volumes whose radii increase with depth, notwithstanding variations in the NMR signal density distribution. Nevertheless, DRESS is a simple and versatile localization procedure that is readily adaptable to spectral relaxation time measurements by adding inversion or spin-echo refocusing pulses or to in vivo solvent-suppressed spectroscopy of proton (1H) metabolites using a combination of chemical-selective RF pulses. Also, the spatial information gathering efficiency of the technique can be improved to provide simultaneous acquisition of spectra from multiple volumes by interleaving excitation of adjacent planes within the normal relaxation recovery period. The spatial selectivity can be improved by adding additional selective excitation spin-echo refocusing pulses to achieve full, three-dimensional point resolved spectroscopy (PRESS) in a single excitation sequence. Alternatively, for samples with short spin-spin relaxation times, DRESS can be combined with other localization schemes, such as image-selected in vivo spectroscopy (ISIS), to provide complete gradient controlled three-dimensional localization with a reduced number of sequence cycles.

Abstract: Preface to the series. Preface. 1. P.P. Feofilov and the spectroscopy of activated crystals (A.A. Kaplyanskii and A.I. Ryskin). 2. Crystal field and electron-phonon interaction in the rare-earth ionic paramagnets (B.Z. Malkin). 3. Coherent transient and holeburning spectroscopy of rare earth ions in solids (R.M. Macfarlane and R.M. Shelby). 4. Experimental studies of energy transfer in rare earth ions in crystals (W.M. Yen). 5. Energy transfer in crystals (D.L. Huber). 6. Spectral migration of excitations in rare-earth activated glasses (T.T. Basiev, V.A. Malyshev and A.K. Przhevuskii). 7. Spectroscopy of collective states and co-operative transitions in disordered rare earth activated solids (V.V. Ovsyankin). 8. Ion-ion interactions and exciton effects in rare earth insulators (R.L. Cone and R.S. Meltzer). 9. Spectroscopic studies of Jahn-Teller phase transitions in rare earth crystals (R.T. Harley). 10. Studies of spin systems by means of light scattering in paramagnetic crystals (S.A. Al'tshuler, A.Kh. Khasanov and B.I. Kochelaev). 11. Electron paramagnetic resonance in the excited states of rare earth ions in crystals (R. Furrer). 12. Optical detection of spin-system magnetization in rare-earth activated crystals and glasses (V.S. Zapasskii). Author index. Subject index. Materials index. Cumulative index.

Abstract: We present the theory of laser-induced radiative association in terms of a scattering resonance formalism and apply this theory to the specific case of Na atom collisions at a temperature of 10 mK. Use of ultracold atoms permits a new kind of high-resolution free-bound spectroscopy for the study of near-threshold collisions and excited-state energy levels which are difficult to study by conventional bound state spectroscopy.

Abstract: I. Spectroscopy, Structure, Potentials.- A. Rotational Spectra.- Rotational Spectroscopy of Weakly Bound Complexes: Capabilities and Limitations.- Pulsed-Nozzle, Fourier-Transform Microwave Spectroscopy of Hydrogen-Bonded Dimers.- Structure Determination of Weakly Bound Complexes.- Microwave Spectra and Weak Intramolecular Hydrogen Bonding in 3-Butene-1-Thiol and N-Methylallylamine.- B. Rotation-Vibrational Spectra.- High Resolution Infrared Spectroscopy of van der Waals Molecules.- Vibration-Rotation Spectroscopy of ArHCl by Far-Infrared Laser and Microwave/Far-Infrared Laser Double Resonance Spectroscopy.- Vibrational Anomalies and Dynamic Coupling in Hydrogen-Bonded van der Waals Molecules.- Slit Jet IR Absorption Spectroscopy of Molecular Complexes.- Sub-Doppler Resolution Infrared Spectroscopy of Binary Molecular Complexes.- The Infrared Spectrum of H2-Ar: New Observations in the v=l-0 and 2-0 Bands of H2.- Dynamical Properties of Simple Hydrogen-Bonded Clusters.- Infrared Spectroscopy of Hydrogen-Bonded and van der Waals Complexes.- Ab Initio Calculations of Vibrational Frequencies and Infrared Intensities for the Hydrogen- Bonded Complex HCN-HF.- The Role of Tunneling Models in Analyzing High- Resolution Spectra of Weakly Bound Molecular Complexes.- Bibliography of Rotational Spectra of Weakly Bound Complexes.- C. Electronic Spectra.- Structure and Dynamics of Mercury van der Waals Complexes.- The Structure of van der Waals Molecules of s-Tetrazine.- Spectra of Mixed Dimers.- Solvent Shifts, Spectroscopy and Structure in van der Waals Complexes of Perylene.- Spectroscopy in the Visible and Near Ultraviolet Region of Some Organic Molecules and their van der Waals Complexes.- Supersonic Jet Spectroscopy of Complexes of Carbazole and N-Ethyl Carbazole with Alkyl Cyanides.- Photoionization of Hydrogen-Bonded Molecular Aggregates.- D. Potential Functions.- The Unavoidable Importance of Electrostatic Effects in the Structures of Weakly Bonded Complexes.- Intermolecular Potentials, Internal Motions and the Spectra of van der Waals Molecules.- Non-Bonding Atom-Diatom Potentials via a Double Many-Body Expansion Method.- The Determination of Intermolecular Forces by Data Inversion Methods.- Transport Properties of van der Waals Molecules Computed from Accurate Interactions.- Determination of Anisotropic Interaction Potentials from Rotational State Resolved Scattering Data.- van der Waals Interactions from Glory and Diffraction Scattering.- High Resolution Crossed Molecular Beam Studies of van der Waals Forces.- E. Summary: Part.- Where Are We in Weak Intermolecular Interactions?.- II. Dynamics.- Interpretation of Linewidths in the Infrared Photodissociation Spectra of van der Waals Molecules.- Infrared Photodissociation of van der Waals Complexes Selectively Prepared by Molecular Beam Scattering.- IR Dissociation of Weakly Bound van der Waals Complexes: (SF6)n, (SiF4)n, (SiH4)n, (C2H4)n,(n=2,3) in the 9-11 in ?m Range.- Infrared (9-11?m) Dissociation of the Hydrogen Bonded Clusters (NH3)n (n?2)Detected by Bolometric Technique.- Highly Excited Systems.- Vibrational Predissociation Dynamics of the Nitric Oxide Dimer.- Complex Forming Reactions in Noble Gas Clusters.- Structure and Dynamics of the Rare Gas-Halogen van der Waals Molecules: Product State Distributions for Vibrational Predissociation of NeBr2.- Dynamics of Energy Transfer in van der Waals Molecules of s-Tetrazine and Argon.- Theory of van der Waals Photofragmentation Dynamics.- Dissociation Dynamics of the He-I2-Ne van der Waals Complex.- Dynamics of the Ar---H2 van der Waals Complex: A Diabatic Distorted Wave Approach Including Discrete-Discrete Couplings.- Vibrational Predissociation Dynamics of Weakly Bonded Dimers: A Summary.- List of Participants.- List of Contributors.- List of Poster Papers.- List of Names.

Abstract: X-ray induced photoelectron spectroscopy, bremsstrahlung-isochromat spectroscopy, and electron energy-loss spectroscopy were used to investigate the electronic structure of the high-temperature superconductor La2−xSrxCuO4 In general, good agreement was obtained with band structure calculations of the tetragonal phase of La2CuO4 Near the Fermi energyEF the systems shows forx=0 a smeared out gap or a region of very low density of states ∼2eV wide Upon replacement of La by Sr, the gap is filled with defect states, the intensity of which is proportional tox The experimental data are not consistent with the closing of a Peierls gap alone

Abstract: Optical spectroscopy of electronic centers in solids.- Excitation transfer in disordered systems.- Dynamics of incoherent transfer.- General techniques and experimental methods in laser spectroscopy of solids.- High resolution laser spectroscopy of ions in crystals.- Laser excited fluorescence spectroscopy in glass.- Excitation Dynamics in Molecular Solids.- Addendum (to the Second Edition).

Abstract: The effect on the superconducting transition temperature of exchanging /sup 18/O for /sup 16/O in La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ has been studied. The concentration of the two isotopes has been determined by Rutherford backscattering spectroscopy and Raman spectroscopy confirmed the mass-related phonon frequency shift. The /sup 18/O substitution is found to be the same on the two O sites. Magnetic measurements of the transition temperature reveal a nonzero isotope effect (..cap alpha.. = 0.16 +- 0.02). The exponent ..cap alpha.. has also been calculated within a conventional electron-phonon interaction model and was found to be significantly larger.

Abstract: Laser-induced breakdown spectroscopy was used to determine uranium in solution for possible application to process control in nuclear fuel reprocessing facilities. Pulses from a Nd: YAG laser were focused on the surfaces of the liquids in order to generate the sparks. The spark light was spectrally resolved and detected with the use of a time-gated photodiode array. The detection limit for uranium in 4 molar nitric acid was 0.1 g/L. Measurement precisions were 1–2% for a 4.2-g/L solution with the use of 1600 laser sparks, corresponding to a measurement time of about three minutes. A calibration curve was prepared that spanned uranium concentrations from 0.1 to 300 g/L. The effects of some experimental parameters on the analysis are discussed.

Abstract: High-power pulsed-laser--induced reactive quenching at liquid-solid interface is used for the first time to synthesize a metastable form of iron oxide. The oxide phase is characterized by using the techniques of conversion-electron M\"ossbauer spectroscopy, Rutherford backscattering spectrometry, x-ray diffraction, and x-ray photoelectron spectroscopy.

Abstract: Laser-Induced Breakdown Spectroscopy (LIBS) has been used to provide a rapid analysis of metals at distances between 0.5 and 2.4 m from the focusing lens and light-collection optics. The laser sparks were generated with the use of pulses from a Nd:YAG laser, and the spark light was collected by the use of a fiber optic cable. The wide acceptance angle of the cable relaxed the constraint that the spark be formed at a precise location for maximum light-collection efficiency and allowed the detection system to be placed remote from the sample. The identification of the main elemental component of eight metals using lines over a 40-nm spectral region was demonstrated by the use of a single laser pulse to record each spectrum. The accuracy and precision of analysis of the minor constituents of steel were determined, and the effect of surface contamination was examined. The application of LIBS to some industrial monitoring situations is discussed.

Abstract: k-resolved inverse-photoemission spectroscopy has been used to determine the empty surface-state band structures of Si(111)..sqrt..3 x ..sqrt..3 -Al, -Ga, and -In surfaces. The results are compared with first-principles pseudopotential total-energy and electronic-structure calculations for energy-minimized geometries of the filled- (T/sub 4/) and the hollow- (H/sub 3/) site adatom models. Good agreement between experiment and theory for the unoccupied surface-state band structures is found for the T/sub 4/ model, which also has the lowest total energy.

Abstract: The heavy-ion mass spectrum obtained in the inner coma of comet Halley with the PICCA instrument on the Giotto spacecraft has been examined. Short polymer chains of polyoxymethylene and their decay products are identified as the source for the spectrum with six mass peaks between about 45 and 120 atomic mass units. The properties of polyoxymethylene are consistent with many of the unexpected observations in the coma.

Abstract: A time‐of‐flight diagnostic for analysis of relatively low‐energy ion beams is described. The system incorporates several novel features which improve its performance in a number of ways. The technique is simple and can provide an alternative to magnetic analysis of ion beams for the determination of ion charge state and beam composition.

Abstract: The basic experimental aspects of Fourier transform Raman Spectroscopy are reviewed with an emphasis on detector technology. The sensitivity is comparable to dispersive Raman Spectroscopy using visible lasers. The ease of spectral subtraction is demonstrated and examples are given showing the elimination of fluorescence.

Abstract: We present a procedure whereby a sheet of donor atoms is incorporated in (100) Si during molecular beam epitaxial growth. Analysis by secondary ion mass spectroscopy and transmission electron microscopy shows that the width of such δ‐function doping layers is only a few lattice planes. Tunneling spectroscopy and transport measurements give evidence for quantum confinement of the electronic charge in the layer and thus confirm the narrow width.

Abstract: The magnitude and temperature dependence of most of the properties of amorphous solids are anomalous at very low temperatures ( less, similar1 Kelvin). Phonon-assisted tunneling of a distribution of glassy bistable configurations, or two-level systems, can account for these anomalies. A unified understanding of the low-temperature properties is required for an understanding of the glassy state. Persistent nonphotochemical hole burning of impurity optical transitions allows a glass state to be produced that is thermally inaccessible to the preburn state, and that allows the probing of tunneling dynamics on time scales that range between picoseconds and days. These data combined with recently obtained distribution functions for the two-level systems offer new insights into the tunneling dynamics.

Abstract: The perpendicular transport of photoexcited electrons and holes in graded-gap GaAs-AlGaAs superlattices is directly determined by subpicosecond luminescence spectroscopy. We show that the electron and and hole transport is through extended, Bloch-type states for superlattice periods 40 A\r{}, and determine the mobility for such transport. Increasing the superlattice period to 60 A\r{} reduces the mobility by a factor of 20, resulting from an order of magnitude reduction in the hole miniband width. Our results also provide the first evidence of diffusion enhanced by potential steps.

Abstract: The theoretical background and experimental implementation of overtone NMR spectroscopy of quadrupolar nuclei, i.e., the direct observation of NMR signals at multiples of the Larmor frequency, are described. Perturbation theory is used to derive expressions for the dependence of overtone NMR frequencies, transition moments, and dipole–dipole splittings on molecular orientation for a nucleus with arbitrary spin. Experimental techniques for overtone cross‐polarization and for two‐dimensional spectroscopic measurements of transition moments and dipole–dipole splittings are demonstrated with 14N overtone spectra of single crystals. Overtone powder pattern line shapes are analyzed, both for spin S=1 and spin S=3/2 nuclei, and examples of 14N overtone powder patterns are presented. Overtone spectroscopy can be used to characterize quadrupole and dipole–dipole interactions in polycrystalline samples. The sensitivity, resolution, and spectral width characteristics of overtone NMR spectra are discussed and contrasted with those of conventional NMR spectra. The sensitivity and resolution of overtone spectra are shown to be comparable to those of conventional spectra, while the reduced spectral width of overtone spectra is a significant advantage in studies of single crystals and, in particular, polycrystalline materials.

Abstract: We report center‐of‐mass kinetic energy distributions for the 193 nm photodissociation of H2S and HBr using the method of velocity–aligned Doppler spectroscopy. Nascent H atoms are detected by sequential two‐photon photoionization via Lyman‐α (121.6 nm + 364.7 nm), and internal SH(X 2Π) and Br excitations are observed directly in the H‐atom kinetic energy distributions. The kinetic energy resolution is much better than in ‘‘conventional’’ sub‐Doppler resolution spectroscopy and results from detecting spatially selected species whose velocities are aligned with the wave vector of the probe radiation, kprobe, thereby providing a kinetic energy distribution for a specific laboratory direction. This improved resolution is achieved in the present experiments by using pulsed, collimated, and overlapped photolysis and probe beams, but the vital aspect of the technique involves increasing the delay between the two lasers in order to discriminate against species having velocity components perpendicular to kprobe. ...