相关论文: NMR of liquid 3He in clay pores at 1.5 K

We report theoretical calculations of the normal-state spin diffusion coefficient of 3He in aerogel, including both elastic and inelastic scattering of 3He quasiparticles, and compare these results with experimental data for 3He in 98%…

We demonstrate time reversal of nuclear spin dynamics in highly magnetized dilute liquid 3He-4He mixtures through effective inversion of long-range dipolar interactions. These experiments, which involve using magic sandwich NMR pulse…

The experimental investigation of superfluid turbulence in 3He-B is generally not possible with the techniques which have been developed for 4He-II. We describe a new method by which a transient burst of turbulent vortex expansion can be…

We demonstrate a minimally invasive nuclear magnetic resonance (NMR) technique that enables determination of the surface-area-to-volume ratio (S/V) of soft porous materials from measurements of the diffusive exchange of laser-polarized…

In porous material research, one main interest of nuclear magnetic resonance (NMR) diffusion experiments is the determination of the exact shape of pores. It has been a longstanding ques-tion if this is achievable in principle. In this…

After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low…

The capability of performing accurate measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the…

Research efforts ranging from studies of solid helium to searches for a neutron electric dipole moment require isotopically purified helium with a ratio of 3He to 4He at levels below that which can be measured using traditional mass…

Nuclear magnetic resonance is widely used as a probe of pore geometry and fluid composition in well logging. One of the critical assumptions often made is that the diffusion of fluid molecules is sufficiently fast to warrant the condition…

Aims. This article aims to provide an alternative method of measuring the porosity of multi-phase composite ices from their refractive indices and of characterising how the abundance of a premixed contaminant (e.g., CO2) affects the…

We have extended the utility of NMR as a technique to probe porous media structure over length scales of ~ 100 - 2000 micron by using the spin 1/2 noble gas 129Xe imbibed into the system's pore space. Such length scales are much greater…

In this contribution, we compute the $^1$H nuclear magnetic resonance (NMR) relaxation rate of liquid water at ambient conditions. We are using structural and dynamical information from Coupled Cluster Molecular Dynamics (CCMD) trajectories…

Most theoretical treatments of Nuclear Magnetic Resonance (NMR) assume ideal smooth geometries (i.e. slabs, spheres or cylinders) with well-defined surface-to-volume ratios (S/V). This same assumption is commonly adopted for naturally…

We investigate the effectiveness of the Inverse Laplace Transform (ILT) analysis method to extract the distribution of relaxation rates from nuclear magnetic resonance data with stretched exponential relaxation. Stretched-relaxation is a…

The present work emphasizes the relevance of low-field NMR relaxometry to investigate colloid-polymer hydrogels by probing water dynamics across a wide range of formulations between $\rm 10^{\circ}C$ and $\rm 80^{\circ}C$. By examining the…

The suitability of a transportable 3He-spin filter as temporary broadband polarizer for a Time-of-Flight neutron reflectometer is demonstrated. A simple two-wavelength method for characterisation of a 3He-spin filter is proposed, which can…

In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI…

We demonstrate the application of implanted-ion $\beta$-detected NMR as a probe of ionic liquid molecular dynamics through the measurement of $^8$Li spin-lattice relaxation (SLR) and resonance in 1-ethyl-3-methylimidazolium acetate. The…

Atomistic molecular dynamics simulations are used to investigate $^1$H NMR $T_1$ relaxation of water from paramagnetic Gd$^{3+}$ ions in solution at 25$^{\circ}$C. Simulations of the $T_1$ relaxivity dispersion function $r_1$ computed from…

Enzyme immobilization plays a crucial role in enhancing the stability and recyclability of enzymes for industrial applications. However, traditional methods for quantifying enzyme loading within porous carriers are limited by time-consuming…