publicationDate stringlengths 10 10 | abstract stringlengths 0 37.3k | title stringlengths 1 5.74k | doi stringlengths 11 47 ⌀ |
|---|---|---|---|
1994-01-01 | In this chapter we provide the basic properties of the coherent-state technique and its application to the interaction of radiation with matter. Greater details about this technique can be found in books by Klauder and Sudarshan (1968), Malkin and Man’ko (1979), Klauder and Skagerstam (1985), Perelomov (1986), Peřina (... | Coherent states | null |
1994-01-01 | The magnetic and structural phase diagrams of the title systems are reviewed, with an emphasis on our recent results obtained from magnetic and structural neutron diffraction, thermogravimetric analysis, iodometric titration, magnetic susceptibility x ( T ), and ^139La nuclear quadrupole resonance (NQR) measurements. F... | The Phase Diagrams and Doped-Hole Segregation in La_2CuO_4+δ
and La_2−xSr_xCuO_4+δ
(x ≤ 0.15, δ ≤ 0.12) | null |
1994-01-01 | The talk extends the theoretical description^1–4 of inelastic electron scattering in plane wave impulse approximation (PWIA) to inclusive processes with polarized electron beams and polarized trinucleon targets. A polarized ^3He target is especially interesting as a possible substitute for a neutron spin target^5. The ... | Spin-Dependent Inelastic Electron Scattering from Three-Nucleon Bound States | null |
1994-01-01 | The main questions raised so far concerned the Brownian motion as a real phenomenon. The problem of relating it to quantum mechanics was only touched upon. Now that we have the material to penetrate deeper into the subject, we shall, in the present chapter, give an account of the functional integral description of inte... | The Feynman-Kac Formula | null |
1994-01-01 | The bulk of my talk today will be presented in the spirit of pure mathematics -as a systematic account of the properties of certain Lie algebras of linear operators. The study of these Lie algebras was inspired by the study of the physics literature and to a considerable extent can be regarded as a unification, systema... | A Connection between Lie Algebra Roots and Weights and the Fock Space Construction | null |
1994-01-01 | Classical theories of exploration and play predict or explain why these behaviors exist and why they are a significant force in development (Groos, 1901; Hall, 1920; Lazarus, 1883; Schiller, 1954). Most early twentieth-century theorists dealt with exploration and play as a secondary topic of interest, because each of t... | The Relationship Between Attachment, Temperament, and Exploration | null |
1994-01-01 | Das Steiner-Problem in Graphen besteht darin, zu einem gegebenen kantenbewerteten Graphen einen Teilgraphen zu bestimmen, der eine vorgegebene Teilmenge der Knotenmenge kostenminimal aufspannt. Praktische Probleme bei der Konstruktion von Netzwerken oder im Bereich des VLSI-Design lassen sich oftmals in bekannte kombin... | Steiner Tree Heuristics — A Survey | null |
1993-12-01 | The theory of electron spin relaxation in protein solutions taking into account the “two-motion” model of spin label mobility is developed. The relations obtained for the longitudinal and transverse relaxation rates describe the experimental results better than isotropic (“one-motion”) model. The mechanism of longitudi... | Investigation of the molecular motion of spin-labeled lysozyme in solution by the use of ESP spectra and electron spin relaxation | null |
1993-12-01 | In order to understand the role of 2-phenylethylamine (PE) on neuronal responses, membrane changes have been studied using ESR probes. We report that the anticipated change in lipid membrane fluidity generally implicated in signal transduction has not been observed when PE is added to synaptosomes. As cytoskeletal arch... | Investigations into the biochemical basis of neuromodulation by 2-phenylethylamine: Effect on microtubule protein | null |
1993-12-01 | The lifeform and the biological production of pure stands of Eichhornia azurea Kunth in three lakes in tropical Brazil were studied. The lifeform of E. azurea is termed ‘semi-emergent’, because the plant has well developed trailing stems just under the water, and the aerial lamina emerges with the thick petiole. The de... | Vegetative growth and productivity ofEichhornia azurea with special emphasis on leaf dynamics | null |
1993-11-01 | Five demographical factors influencing the sex ratio of a population are classically considered. The influence of two of them is dependent on the longevity of individuals in the population. The effect of differential age at maturity between males and females is higher for animals with low annual survival, whereas the e... | Effects of sexual differences of age at maturity and survival on population sex ratio | null |
1993-10-01 | The effect of salts (KI, KBr, NaCl, KC1, KF, phosphate, and Na_2SO_4) on the stability of β-galactosidase in aqueous solution was studied from the aspect of changes in water mobility. At salt concentrations up to 200 m M , the inactivation rate of β-galactosidase in all the salt solutions studied increased with increas... | The Effect of Salts on the Stability of β-Galactosidase in Aqueous Solution, as Related to the Water Mobility | null |
1993-10-01 | Limits of sequences of finite-dimensional (AF) C ^*-algebras, such as the CAR algebra for the ideal Fermi gas, are a standard mathematical tool to describe quantum statistical systems arising as thermodynamic limits of finite spin systems. Only in the infinite-volume limit one can, for instance, describe phase transiti... | Logic of infinite quantum systems | null |
1993-09-01 | We reconsider the conceptual foundations of the renormalization-group (RG) formalism, and prove some rigorous theorems on the regularity properties and possible pathologies of the RG map. Our main results apply to local (in position space) RG maps acting on systems of bounded spins (compact single-spin space). Regardin... | Regularity properties and pathologies of position-space renormalization-group transformations: Scope and limitations of Gibbsian theory | null |
1993-09-01 | We report a neutron scattering investigation of a La_1.65Nd_0.35CuO_4 single crystal which undergoes a second order structural transition with decreasing temperature from a high temperature orthorhombic phase (space group Bmab) to a distinct low temperature orthorhombic phase (space group Pccn) at T _ s =76 K. The tran... | Soft phonon behavior and magnetism at the low temperature structural phase transition of La_1.65Nd_0.35CuO_4
| null |
1993-08-01 | Combination of nonselective and selective excitation in NMR experiments of discriminating and assigning spin systems is proposed. | Combination of nonselective and selective excitation in NMR experiments of discriminating and assigning spin systems | null |
1993-08-01 | The population and production ecology of a Zizania latifolia stand at a sheltered shore of the Hitachi-Tone River were investigated. Shoot emergence was observed twice a year; the fist was a synchronized shoot emergence in April and the second was from August to October. Aboveground biomass was mostly occupied by leave... | Population dynamics, productivity and biomass allocation of Zizania latifolia in an aquatic-terrestrial ecotone | null |
1993-08-01 | Time-domain electron-spin-resonance studies on p -benzoquinone using ethanol and isopropanol as solvents show emissively polarized ESR spectra of semiquinone and hydroxyalkyl radicals within 0·5 μs after the laser pulse at 248 nm. The hydrogen abstraction from the alcohols by the triplet excited quinone is concluded to... | Time-domain electron-spin-resonance studies on hydrogen atom transfer to photoexcited quinones | null |
1993-08-01 | We consider the quantum spin-1/2 Ising chain in a uniform transverse magnetic field, with an aperiodic sequence of ferromagnetic exchange couplings. This system is a limiting anisotropic case of the classical two-dimensional Ising model with an arbitrary layered modulation. Its formal solution via a Jordan-Wigner trans... | Critical behavior of the aperiodic quantum Ising chain in a transverse magnetic field | null |
1993-08-01 | This review of gerontological theory cites diverse examples of neural and endocrine involvement in the senescence of mammals and some other multicellular species that suggest fundamental involvement in age-related changes in cell functions. The data support the major hypothesis that age-related changes are generally ca... | Theories of aging | null |
1993-08-01 | A theory of sideband intensity is derived by expanding into a Taylor series the free induction decay observed under magic angle spinning (MAS). According to this procedure, the free induction decay signal is completely represented by a basis of irreducible tensors from rank zero to rank infinity. After averaging over a... | An approximate method of sideband intensity calculation in magic angle spinning NMR | null |
1993-07-01 | The magnetic signals emitted by a moving A–B interface are calculated using the spin hydrodynamic theory and the general boundary conditions at the A–B interface. Most experimental observations^1 are well accounted for. We especially find the following behavior for the excess magnetization: (i) It vanishes if the inter... | The magnetic signals accompanying the moving A–B interface of superfluid^3He | null |
1993-06-01 | The relaxational dynamics for local spin autocorrelations of the spherical p -spin interaction spin-glass model is studied in the mean field limit. In the high temperature and high external field regime, the dynamics is ergodic and similar to the behaviour in known liquid-glass transition models. In the static limit, w... | The sphericalp-spin interaction spin-glass model | null |
1993-06-01 | Spin-labelling method in combination with modern versions of ESR spectroscopy allows one to study intramolecular dynamics of protein globules and surrounding molecules of water in a wide range of correlation times ( τ _c = 10^2−10^−11 s) and amplitudes and phonon processes as well. Experimental results for a number of ... | Low temperature protein dynamics studied by spin-labelling methods | null |
1993-06-01 | Several theoretical aspects in leading (1-loop) and higher (2-loop) order as well as various approaches of extracting leading twist-2 parton distributions from structure function measurements are discussed and summarized. Their implications for the small- x region ( x ⩽10^−2) are analyzed and compared with alternative ... | Parton distributions, small-x physics and the spin structure of the nucleon | null |
1993-06-01 | The article describes the model of the spin label behaviour, where the spin label attached to the protein aminoacid residue simultaneously accomplishes two different motions: the fast anisotropic reorientation of the label itself (with τ≫1 nsec) relative to the protein molecule and the slow isotropic diffusion (with τ>... | About new universal approach to the EPR-spectra simulation of the spin-labeled macromolecules | null |
1993-06-01 | Peroxidation of egg yolk phosphatidylcholine (egg PC) liposomes was induced by addition of ascorbic acid (AsA) and Fe(II) in the presence of a trace of autoxidized egg PC (PC−OOH), but not in the absence of PC−OOH. PC−OOH was degraded upon addition of AsA and Fe(II) but not of either one alone. The results suggest that... | Dynamics of iron-ascorbate-induced lipid peroxidation in charged and uncharged phospholipid vesicles | null |
1993-06-01 | α-Tocopherol, ubiquinone-10 and ubiquinol-10 have been studied by high resolution magic angle samples spinning ^13C-nuclear magnetic resonance in egg yolk phosphatidylcholine multilamellar vesicles model membranes in order to assess their location and the induced perturbations on this model system. α-Tocopherol is plac... | Magic angle spinning ^13C-NMR spin-lattice relaxation study of the location and effects of α-tocopherol, ubiquinone-10 and ubiquinol-10 in unsonicated model membranes | null |
1993-05-01 | Five satellites of Neptune orbit under the synchronous zone. In this sense the Neptune's system is similar to that of Uranus (nine satellites) and differs from Jupiter (two) and Saturn (zero). The basic parameters describing the angular momentum within the Neptune's system and of its tidal evolution are estimated. The ... | Angular momentum and tidal evolution | null |
1993-05-01 | We present simultaneous field measurements of NO_3 and peroxy radicals made at night in a forested area (Schauinsland, Black Forest, 48° N, 8° N, 1150 ASL), together with measurements of CO, O_3, NO_ x , NO_ y , and hydrocarbons, as well as meteorological parameters. NO_2, NO_3, HO_2, and ∑(RO_2) radicals are detected ... | Simultaneous measurements of peroxy and nitrate radicals at Schauinsland | null |
1993-05-01 | The side chain motion and structure of the racemic mixture of poly(γ-benzyl glutamate) (PBDLG) in the solid state were studied by means of the cross polarization/magic angle spinning (CP/MAS) ^13C NMR. C_β and C_γ regions of NMR spectra for PBDLG in the stacked state of phenyl rings exhibit a remarkable difference from... | Side Chain Motion and Structure of Racemic Poly(γ-benzyl glutamate) as Studied by Solid State High-Resolution ^13C Nuclear Magnetic Resonance | null |
1993-04-01 | A system of equations that permits calculation of the longitudinal correlation function in terms of the correlation functions of the transverse spin components is proposed. In the Green's function method, the system permits calculation of the susceptibility, mean energy, and specific heat in the same approximation as t... | Specific heat and mean energy of a Heisenberg ferromagnet in the Green's function method | null |
1993-04-01 | Deux espéces de tordeuses des feuilles, Cnaphalocrocis medinalis (Guenée) et Marasmia patnalis Bradley sont habituellement identifiqes en association avec des plantes de riz en Asie du Sud et Asie du Sud Est. Les larves de ces deux espéces sont identiques morphologiquement et en ce qui concerne leur comportement alimen... | Spinning Behaviour of Two Species of Rice Leaffolders, Cnaphalocrocis Medinalis (Guenée) and Marasmia Patnalis Bradley (Lepidoptera: Pyralidae) | null |
1993-03-01 | The site diluted finite spin cluster system Rb_2CO_ x Mg_1− x F_4 ( x =0.15, 0.4, 0.5) has been investigated by the μ^+SR technique. Muon spin relaxation was observed in these diluted magnetic systems in a weak longitudinal field of 100 G. By reducing temperature below 100 K, the experimental data show features of slow... | Spin dynamics in a site diluted finite spin cluster system probed by positive muons | null |
1993-03-01 | The temperature dependence and the anisotropy of the Knight shift and the spin-lattice relaxation time ( T _1) at the Cu and the O sites of the full over-doped Tl_2Ba_2CuO_ y ( T _c=0 K: Tl2201L) were measured. The Knight shift values at the Cu and the o sites in the CuO_2 plane are larger in Tl2201L compared to those ... | NMR study of the spin dynamics in full over-doped Tl_2Ba_2CuO_
y
(T
_c=0 K) | null |
1993-03-01 | An unambiguous determination of the μ^+ location in the high T _c LaSrCuO superconductor is made through zero-field spin relaxation in the paramagnetic phase and its crystal axis dependence by using single crystalline samples. The temperature dependence of the relaxation rates has a maximum between 80 and 150 K, indica... | Behavior of positive muons in highT
_c superconductors La_2−x
Sr_
x
CuO_4
| null |
1993-03-01 | Conformational rate processes in aqueous solutions of uniformly ^15N-labeled pancreatic trypsin inhibitor (BPTI) at 36°C were investigated by measuring the rotating frame relaxation times of the backbone ^15N spins as a function of the spin-lock power. Two different intramolecular exchange processes were identified. A ... | Protein dynamics studied by rotating frame ^15N spin relaxation times | null |
1993-03-01 | We have measured the temperature ( T ) dependence of the transverse relaxation rate ( T _G ^−1 ) of the Cu(1) nuclear spin in YBa_2Cu_3O_6.98 ( T _c=92 K) and YBa_2Cu_4O_8 ( T _c=82 K). From the scaling ratio of T _G ^−2 (Cu1) to T _G ^−2 (Cu2), we have estimated the strength of a covalent bonding between the CuO_2 pla... | Cu nuclear spin-spin relaxation in YBa_2Cu_3O_6.98 and YBa_2Cu_4O_8
| null |
1993-03-01 | The theory of solid-state nuclear magnetic resonance (NMR) spectroscopy is reviewed, with specific discussions of magnetic interactions in the solid state. Each magnetic interaction (Zeeman, dipole-dipole, chemical-shift, spin–spin, and quadrupolar) is addressed and manifestations of these interactions in the solid sta... | Solid-State Nuclear Magnetic Resonance Spectroscopy: Theory and Pharmaceutical Applications | null |
1993-03-01 | This study reports the results of an investigation of the relation between one measure of the performance of firms, work injuries, and the number of first level supervisors for 140 chemical, paper, and wood product manufacturing firms. Additional numbers of supervisors were found to be associated with lower work injuri... | Safety issues beyond the workplace: Estimate relationships between work injuries and available supervision | null |
1993-02-01 | We have found a chaotic regime of counter-motion of the normal and superfluid magnetizations in^3He-B. It takes place under conditions corresponding to the experiments with “catastrophic” relaxation. We study a spatially homogeneous regime of the magnetization's precession by employing a numerical simulation of the Leg... | A chaotic regime of internal precession in^3He-B | null |
1993-02-01 | The rotating frame ^13C spin-lattice relaxation time for poly(γ-benzyl L -glutamate) (PBLG) in the solid state was measured by the cross polarization/magic angle spinning (CP/MAS) NMR. From the ^13C spin-lock frequency dependence of ‘observed’ relaxation time T _1ρ^*, it was revealed that the spin-lattice process with ... | Side Chain Dynamics in Poly(γ-benzyl L-glutamate) as Studied by High-Resolution Solid State ^13C Nuclear Magnetic Relaxation in Rotating Frame | null |
1993-02-01 | Heptakis(2,6-di- O -ethyl)-β-cyclodextrin (DE-β-CyD) was prepared and its ^1H and ^13C nuclear magnetic resonance (NMR) signals in DMSO-d_6 were unequivocally assigned by two-dimensional COSY and ROESY. The results on ^1H coupling constants indicated that all ethylated glucose units are in a ^4C_1 chair conformation. T... | Preparation of Heptakis(2,6-di-O-ethyl)-β-cyclodextrin and Its Nuclear Magnetic Resonance Spectroscopic Characterization | null |
1993-01-01 | It has been realized in recent times that the elementary excitations in Heisenberg ferromagnetic systems can be characterized by spatially compact solitons in addition to the linear spin waves (magnons).^1–4 Hence rigorous attempts were made after the discovery of the concepts of soliton and inverse scattering transfor... | On the Discrete and Continuum Integrable Heisenberg Spin Chain Models | null |
1993-01-01 | A survey of the theoretical understanding of the spin relaxation processes in quantum wells is given in relation to the recent time-resolved polarization measurements. A new theory is described of the spin dynamics and relaxation of the exciton through the exchange interaction, momentum scattering, and valence band mix... | Theory of Spin Dynamics of Excitons and Free Carriers in Quantum Wells | null |
1993-01-01 | A central goal in modern molecular biophysics is to understand the physical mechanisms of protein function. This problem is often stated as an issue of structure and function, but static structural information, from electron microscopy or X-ray diffraction, has consistently proven to be insufficient for the understandi... | Transient EPR of Spin-Labeled Proteins | null |
1993-01-01 | As shown by the numerous studies described in the literature, high-resolution ^13C NMR has proven to be a most powerful tool for investigating local dynamics in polymers. Unlike fluorescence anisotropy or electron spin resonance techniques, it does not require any labeling of the molecule under study, and yields direct... | High-resolution solid-state ^13C NMR studies of local motions and spin dynamics in bulk polymers | null |
1993-01-01 | Ion channels are proteins in the lipid cell membrane. They spontaneously fluctuate between conformational shapes that are open or closed to the passage of ions. The ionic currents through an individual channel can be resolved by the patch clamp technique. Thus, the time sequence of open and closed conformational states... | Interpretation of protein structure and dynamics from the statistics of the open and closed times measured in a single ion-channel protein | null |
1993-01-01 | The high-resolution neutron spin echo (NSE) spectroscopy provides the unique chance to study the segmental diffusion of polymeric systems simultaneously in space and time. In particular, information on the internal relaxation of single molecules or parts of single molecules may be obtained from dense systems, if the me... | The effect of microscopic spatial restrictions on the segmental diffusion of dense polymer systems: Their observation and analysis by neutron spin echo spectroscopy | null |
1993-01-01 | A pedagogical review of the current theoretical understanding of various collective phenomena in materials with quenched disorder is given. The emphasis is on the nature of ordered phases, their equilibrium dynamics, and development of long-range order and other non-equilibrium dynamic phenomena. The important role pla... | Low Temperature Phases, Ordering and Dynamics in Random Media | null |
1993-01-01 | Over the past ten years or so solid state NMR has become widely used in the study of polymers. The rather late development of solid state NMR, in comparison to solution state, can be attributed to the need for technical developments to permit the acquisition of high resolution solid state NMR spectra. Since the introdu... | Solid State NMR of Synthetic Polymers | null |
1993-01-01 | To get some insight into the role of the gluon field in the recent “proton spin crisis”, the UA (1) Goldberger-Treiman relation is rederived on the basis of some specific effective lagrangrians which incorporates the axial anomaly of QCD. This model analysis indicates “quark spin screening” interpretation of the U _ A ... | An Effective Lagrangian Analysis of the U(1) Goldberger-Treiman Relation | null |
1993-01-01 | We describe the optical dephasing of YLiF_4:Er^3+ using a computer simulation which takes into account the mutual spin flips of 3000 F host nuclei. The highly non-exponential echo decay results from the “frozen core” of nuclear spins near the large Er^3+ magnetic moment, whose spin flip rates are greatly slowed compare... | Computer Simulations of Optical Dephasing of Paragmagnetic Ions | null |
1993-01-01 | Discrete Josephson Structures (DJS) are involved in different fields of low temperatures physics. Here we focus our attention on 1d arrays and 2d square arrays of short Josephson junctions (cfr. Fig. 1). While 1d arrays are interesting for the development of Flux-Flow based devices [1, 2], 2d arrays, besides their intr... | Statics and Dynamics of Flux Vortices in Discrete Systems | null |
1993-01-01 | We discuss experimental results on molecular motion in polymer melts, obtained by neutron spin-echo spectroscopy (NSE). For longer times we observe systematic deviations from the Rouse model, revealing the presence of a well-defined intermediate dynamical length scale beyond which density fluctuations within a given ch... | On the dynamics of dense polymer systems | null |
1993-01-01 | This paper reviews the use of photoluminescence and photoluminescence excitation spectroscopy for the study of low-dimensional electron and hole gases in modulation- and δ -doped semiconductor heterostructures. This type of spectroscopy provides information on the subband structure and band filling in those structures.... | Electronic and optical properties of low-dimensional semiconductor structures | null |
1993-01-01 | Multiple scattering processes dominate quark counting ones in hadronic exclusive reactions at large transfer. We survey currently available evidence for the importance of these processes at present energies. In the case of fixed angle MB → MB and $$B\bar B \to MM'$$ reactions, this implies that dynamics selects baryons... | Asymptotic dominance of diquarks in some exclusive hard reactions | null |
1993-01-01 | We extend the results of a previous calculation concerning the existence of soliton bands in anharmonic quantum lattices. In particular we consider the case where the periodicity f of the lattice is even rather than odd, and we also show that for the two quanta case, the eigenvalues of the discrete nonlinear Schrödinge... | Quantum Solitons in the DNLS and Hubbard Models | null |
1993-01-01 | So far, we have been concerned primarily with electronic properties of molecules when the nuclei are held fixed. However, other properties of molecules are of considerable interest; e.g., vibrational and rotational degrees of freedom are unique to molecules as opposed to atoms. In the present chapter, we shall begin wi... | Molecular Parameters Determined by Spectroscopic Methods | null |
1993-01-01 | We argue that chaotic size dependence is an intrinsic feature of the infiniterange Sherrington-Kirkpatrick (SK) model and should occur in short-range spin glasses if their low temperature behavior is analogous to that of the SK model. Chaotic size dependence offers a new way to distinguish, both numerically and theoret... | Chaotic Size Dependence in Spin Glasses | null |
1993-01-01 | The vibronic fine structure in the S_0 → S_1 and S_0 → T_1 electronic spectra of acetaldehyde and thioacetaldehyde which results from n → π* excitation can be attributed to the activity of the methyl torsion and the aldehyde hydrogen out -of - plane wagging modes. The band patterns in these two spectra were calculated ... | A Comparison of the Methyl Torsion and Aldehyde Wagging Dynamics in the Ground and First Excited States of Acetaldehyde and Thioacetaldehyde | null |
1993-01-01 | Operator algebra methods for study of exactly soluble one-dimensional quantum spin lattice models are briefly reviewed. | Operator Algebra Approach to Soluble Models of Quantum Spin Lattice Systems | null |
1993-01-01 | The coexistence of competing species may be mediated by various mechanisms including resource partitioning and various kinds of environmental heterogeneity. In this paper we show how differences in life history enhance coexistence in stochastic environments. In Drosophila species, as in many other taxa, the development... | Coexistence in Stochastic Environments through a Life History Trade Off in Drosophila | null |
1993-01-01 | The computational results presented show good agreement with existing flight test data. A parametric study on the sensitivity of attachment line location and crossflow profiles to alpha was conducted. For the 20 case, the attachment line is very close to the leading edge. However, for a = 0.00 and 3.670, the outboard a... | Effects of angle of attack on the leading edge attachment line | null |
1993-01-01 | A 3-D least-squares upwind Euler solver for unstructured meshes | null | |
1993-01-01 | A new mechanism of electron spin polarization generation through radical-excited molecule interactions | null | |
1993-01-01 | The inter-plane antiferromagnetic correlation among Cu 3d-spins has been investigated by Tl/Cu-NMR on the copper oxide superconductor TlBa_2CaCu_2O_7−δ. In this system, where the two plane-site copper atoms locate symmetrically above and below Tl site, the fluctuating field induced by 3d-spins of these Cu atoms must be... | Tl/Cu-NMR Study on TlBa_2CaCu_2O_7−δ (Tl1212) | null |
1993-01-01 | ^139La NQR and relaxation measurements in La_2Cu_1−xNi_xO_4for x ranging from zero to one aimed at learning about the effects on the spin excitation and correlation properties of the substitution of Cu^2+ S=1/2 ions by Ni^2+ S=1, are presented.The hyperfine magnetic fields and the electric field gradients at the Lantan... | Effects of Ni to Cu Substitution in La_2CuO_4 from ^139La NQR and Relaxation | null |
1993-01-01 | We present results of differential absorption and four wave mixing experiments in GaAs quantum wells in a magnetic field. Quantum beats between the exciton Zeeman levels and a rotation of the photon echo polarization are observed and analyzed. We show that exciton spin orientation is maintained for several tens of pico... | Coherent Optical Phenomena of Quantum Well Excitons in a Magnetic Field | null |
1993-01-01 | Recent advances in liquid-state theory permit the calculation of thermodynamic quantities and correlation functions for systems in which some of the degrees of freedom are quenched, or frozen in place, while the rest are annealed. Basic examples include models for porous media, crystals containing quenched impurities, ... | Liquid-State Theory for Some Non-Equilibrium Processes | null |
1993-01-01 | The interactions in heavy-electron fluctuating-valence metals are discussed. The conclusion is that the state is closely analogous to “Brinkman-Rice” Fermi liquids like^3He in which parallel-spin effective interactions are attractive and antiparallel interactions strongly repulsive; hence, “triplet”—actually oddparity—... | Heavy-electron superconductors, spin fluctuations, and triplet pairing | null |
1993-01-01 | Free radical reactions are ubiquitous in living things. Studies on the origin and evolution of life provide a reasonable explanation for the prominent presence of this unruly class of chemical reactions. These reactions have been implicated in aging. Aging is the accumulation of changes responsible for the sequential a... | Free Radical Involvement in Aging | null |
1993-01-01 | Demographic information is a prerequisite for the development of effective pest management programs (Levins and Wilson 1980). Knowledge and understanding of fruit fly demography is considered important for several reasons: results from these studies allow us a) to compare life history strategies, b) to interpret sampli... | Demography of Anastrepha Fruit Flies: A Case Study of Three Species of Economic Importance | null |
1993-01-01 | On the Si(OOl) surface, atoms form asymmetric dimers, which are arranged in a c(4 × 2) pattern at low temperatures. As the temperature increases, the ordered phase transforms into a disordered phase around 200 K. This structural phase transition was studied theoretically by using a two-dimensional Ising spin model. The... | Order-Disorder Phase Transition on the Si(001) Surface | null |
1993-01-01 | In recent years, considerable progress has been made toward understanding the active site structures and mechanisms of copper-containing amine oxidases. Copper-containing amine oxidases are one of the most widely distributed classes of “Type-2” copper enzyme. Copper amine oxidases have been highly purified from bacteri... | Structure and Reactivity of Copper-Containing Amine Oxidases | null |
1993-01-01 | Using very simple models it has now become possible to understand the properties of complex fluids, such as microemulsions and liquid crystals. An understanding of the basic science, combined with parallel processing methods, permits one to thoroughly describe phase diagrams, interfacial properties, and neutron scatter... | Long Length-scale Aspects of Self Organization Phenomena | null |
1993-01-01 | The Construction Simulation project will first of all be explained as it has taken shape in the Civil Engineering Division of the Directorate-General for Public Works and Water Management (Rijkswaterstaat) in cooperation with TNO-Bouw, the Building and Construction Department of TNO, the Dutch Organization for Applied ... | Construction simulation of some bridges over the river IJssel | null |
1993-01-01 | We summarize some results of recent copper, oxygen and barium NQR/NMR studies of various Y-Ba-Cu-O compounds. We will deal with: electric field gradients in 1-2-3-7 and 1-2-4-8; ^17O Knight shift and relaxation in 1-2-4-8 (evidence for single spin fluid); thermally activated Ba relaxation process in 1-2-4-8; evidence f... | Probing the Electronic Structure of Y-Ba-Cu-O Superconductors by Cu, O and Ba NQR and NMR | null |
1993-01-01 | Molecular sieves are a class of porous open-framework solids, which includes aluminosilicates (zeolites), aluminophosphates and silicoaluminophosphates of diverse structures. Zeolites, the original molecular sieves, are built from corner-sharing SiO_4 ^4−and A1O_4 ^5− tetrahedra and contain regular systems of intracrys... |
^1H and ^13C Solid-State NMR Studies of Catalytic Reactions on Molecular Sieves | null |
1993-01-01 | Highly oriented polymer fibers can be manufactured in various ways involving different regimes of deformation. Two processes and two different mechanisms of orientation are discussed. The first is strain orientation in a plastic solid subjected to slow deformation. The example of industrial processes include cold-drawi... | Orientation mechanisms in the development of high-performance fibers | null |
1992-12-01 | This is the first in a series of papers on a consistent microscopic theory of transverse dynamics in spin-polarized or binary Fermi liquids. We start from exact microscopic equations in Green's functions at zero temperatures and consider slightly inhomogeneous perturbations. The transverse dynamics is described by an i... | Zero-temperature attenuation and transverse spin dynamics in Fermi liquids. I. Generalized Landau theory | null |
1992-12-01 | Human serum albumin has been studied at low hydration level by the ESR spin labelling technique, under the assumption that a covalently bound spin-label is a reporter of the protein internal dynamics. At room temperature, the presence of a double component signal allowed us to monitor the influence of increasing hydrat... | Hydration and protein dynamics: an ESR and ST-ESR spin labelling study of human serum albumin | null |
1992-12-01 | Subdomain partitioning of n-fold fields associated with S _ n -scalar invariants of Rota-Cayley algebra and enumerative combinatorias are shown to provide direct access to the hierarchical substructure (inventory) of higher identical spin clusters. Such lexical methods based on p -tuples are especially valuable in trea... | Summary ofS
_
n
mapping properties of some lexicalp-tuples, or wordlengths, over (M
_1-M
_2) fields of Rota-Cayley algebra in generating Hilbert space SO(3) xS
_
n
irreps of higherI
_
i
identical spin clusters, [A]_
... | null |
1992-12-01 | We extend the theorem of Burton and Keane on uniqueness of the infinite component in dependent percolation to cover random graphs on ℤ^ d or ℤ^ d × ℕ with long-range edges. We also study a short-range percolation model related to nearest-neighbor spin glasses on ℤ^ d or on a slab ℤ^ d × {0,... K } and prove both that p... | Uniqueness of the infinite component in a random graph with applications to percolation and spin glasses | null |
1992-12-01 | The conformal charge is an important quantity which characterizes the nature of the two-dimensional phase transition. We report a first attempt to use a new numerical method to calculate the conformal charge. In this paper, we apply our method to the 2-dimensional, φ ^4, continuous-spin Ising model. By varying the para... | Monte carlo calculations of the conformal charge | null |
1992-11-01 | A microscopic framework for a generalized Landau theory is established in the form of two coupled equations in “partial transverse densities”. The 4-component effective interaction is related to the irreducible vertex, and not to the full vertex. The results explain the zero-temperature transverse relaxation and attenu... | Transverse spin dynamics in spin-polarized Fermi liquids | null |
1992-11-01 | The sdg interacting boson model (sdgIBM), which includes monopole ( s ), quadrupole ( d ) and hexadecupole ( g ) degrees of freedom, enables one to analyze hexadecupole ( E 4) properties of atomic nuclei. Various aspects of the model, both analytical and numerical, are reviewed emphasizing the symmetry structures invol... | sdg Interacting boson model: hexadecupole degree of freedom in nuclear structure | null |
1992-10-01 | A model describing the adiabatic dynamics of a paramagnetic ion pair in a simple fluid is presented. A mixed classical-quantum mechanical approach is adopted. The quantum degrees of freedom, i.e. the unpaired electron in our case, are treated via the Time dependent Schrödinger Equation, while the other particle are dea... | On the adiabatic dynamics of paramagnetic ion pairs | null |
1992-10-01 | The quantum dynamics of a relativistic spin 1/2 particle moving in the total space P of the principal U (1) bundle associated with the Dirac monopole is described. It is completely characterized in terms of an additional U (1) bundle P ^* that is intimately associated with the scattering problem. A representation in wh... | Relativistic spin 1/2 particle in the total space of the principalU(1) monopole bundle | null |
1992-10-01 | The frequency dependences of ^13C spin-lattice relaxation times ( T _1) and nuclear Overhauser enhancements (NOE) of poly(methyl methacrylate) (PMMA) in CDCl_3 solution have been analyzed in terms of different models describing the motions of the C-H internuclear vector. Box-type and log−χ^2 distribution models of corr... | NMR Measurements of Identical Polymer Samples by Round Robin Method III. Analysis of Frequency Dependences of ^13C Spin-Lattice Relaxation Times and Nuclear Overhauser Enhancements | null |
1992-09-01 | The paper presents the results of four overlapping generations experiments performed at the California Institute of Technology. Overlapping generations markets were created in which each agent had a two period life span. With the exception of the first period, there were eight agents trading in each period; four buyers... | Competitive equilibria in overlapping generations Experiments | null |
1992-09-01 | We study some combinatorial and algorithmic problems associated with an arbitrary motion of input points in space. The motivation for such an investigation comes from two different sources: computer modeling and sensitivity analysis . In modeling, the dynamics enters the picture since geometric objects often model phys... | Transitions in geometric minimum spanning trees | null |
1992-09-01 | Quantitative observation on the seasonal changes in leaf life span, leaf area and biomass of a floating-leaved aquatic plant, Nymphaea tetragona Georgi, were carried out for a year in a small irrigation pond, Japan, by using a non-destructive leaf-marking method. Annual mean life span and turnover rate of floating leav... | Annual net production and life span of floating leaves in Nymphaea tetragona Georgi: a comparison with other floating-leaved macrophytes | null |
1992-09-01 | Comparative spin probe investigation of the properties of human thyroxin-binding sites TBG and apolipoprotein A-1 | null | |
1992-07-01 | We study the Hamiltonian of a two-level system interacting with a one-mode radiation field by means of the Wigner method and without using the rotating-wave approximation. We show that a phenomenon of collapses and revival, reminiscent of that exhibited by the Jaynes-Cummings model, takes place in the high-coupling lim... | Chaos and quantum irreversibility | null |
1992-06-01 | Submicrosecond flash-CIDNP was used to study the dependences of the kinetics and amplitude of CIDNP, arising in biradicals produced in the photolysis of cyclic aliphatic ketones on the temperature and viscosity of the medium. It has been found that for biradicals the geminate CIDNP increases with the diffusion coeffici... | The effett of medium on cidnp kinetics in geminate recombination of biradicals. Experiment and calculation | null |
1992-06-01 | A stochastic model for the dynamics of a macroscopic or classical spin based on a classical generalized Lagrangian formalism is proposed. The model can be used to describe the evolution of the magnetic moment of superparamagnetic particles. In this sense, it is a generalization of the model proposed by Brown, allowing ... | A stochastic model for the dynamics of a classical spin | null |
1992-06-01 | We report ionic conductivities and mobilities of the liquid polymer electrolytes formed by dissolving the lithium salts in poly(ethylene oxide) and poly(propylene oxide). A high resolution NMR (nuclear magnetic resonance) relaxation technique was used to study the dynamics of the ions in polymer electrolytes. The ^7Li ... | Study on the Ionic Conductivity and Mobility of Liquid Polymer Electrolytes Containing Lithium Salts | null |
1992-06-01 | NMR line shifts and spin-lattice relaxation rates of^89Y and^63Cu in YBa_2Cu_3O_6.9 were measured in disordered samples irradiated by fast neutrons with a fluence of: ϕ=5·10^18 cm^−2 ( T _c ^ons =70 K), ϕ=1.2·10^19 cm^−2 ( T _c ^ons =20 K), in order to investigate the evolution of spin susceptibility χ_S under irradiat... | NMR and spin-lattice relaxation rate of^89Y,^63Cu in radiation disordered YBa_2Cu_3O_6.9
| null |
1992-06-01 | ^205Tl-NMR in Tl_2Ba_2Ca_n-1Cu_nO_8−δ for different n and δ is reviewed. For n =2,3 the^205Tl spectra consist of two lines. The main line arises from Tl(1) in the TlO-layer whereas the defect line belongs to Tl(2) in the Ca-layers between the CuO_2-layers. The temperature dependent Knight shift of the Tl(2) (defect) li... | ^205Tl NMR in the Cuprate Superconductor Tl_2Ba_2CaCu_2O_8−δ: Evidence for a pseudo spin gap | null |
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