Magnetic Resonance Letters最新文献_第7页

Radicals on the silica surface: probes for studying dynamics by means of fast field cycling relaxometry and dynamic nuclear polarization 二氧化硅表面的自由基：用快场循环弛豫法和动态核极化法研究动力学的探针

Magnetic Resonance Letters Pub Date : 2023-08-01 DOI: 10.1016/j.mrl.2023.03.006

Bulat Gizatullin, Carlos Mattea, Siegfried Stapf

{"title":"Radicals on the silica surface: probes for studying dynamics by means of fast field cycling relaxometry and dynamic nuclear polarization","authors":"Bulat Gizatullin, Carlos Mattea, Siegfried Stapf","doi":"10.1016/j.mrl.2023.03.006","DOIUrl":"10.1016/j.mrl.2023.03.006","url":null,"abstract":"<div><p>Determining the dynamics of adsorbed liquids on nanoporous materials is crucial for a detailed understanding of interactions and processes on the solid-liquid interface in many materials and porous systems. Knowledge of the influence of the presence of paramagnetic species on the surface or within the porous matrices is essential for fundamental studies and industrial processes such as catalysts. Magnetic resonance methods, such as electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and dynamic nuclear polarization (DNP), are powerful tools to address these questions and to quantify dynamics, electron-nuclear interaction features and their relation to the physical-chemical parameters of the system. This paper presents an NMR study of the dynamics of polar and nonpolar adsorbed liquids, represented by water, n-decane, deuterated water and nonane-d20, on the native silica surface as well as silica modified with vanadyl porphyrins. The analysis of the frequency dependence of the nuclear spin-lattice relaxation time is carried out by separating the intra- and intermolecular contributions, which were analyzed using reorientations mediated by translational displacements (RMTD) and force-free-hard-sphere (FFHS) models, respectively.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 3","pages":"Pages 256-265"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42932647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

On the sampling strategies and models for measuring diffusion exchange with a double diffusion encoding sequence 用双扩散编码序列测量扩散交换的采样策略和模型

Magnetic Resonance Letters Pub Date : 2023-08-01 DOI: 10.1016/j.mrl.2023.05.003

Alfredo Ordinola , Shan Cai , Peter Lundberg , Ruiliang Bai , Evren Özarslan

{"title":"On the sampling strategies and models for measuring diffusion exchange with a double diffusion encoding sequence","authors":"Alfredo Ordinola , Shan Cai , Peter Lundberg , Ruiliang Bai , Evren Özarslan","doi":"10.1016/j.mrl.2023.05.003","DOIUrl":"10.1016/j.mrl.2023.05.003","url":null,"abstract":"<div><p>Water exchange between the different compartments of a heterogeneous specimen can be characterized via diffusion magnetic resonance imaging (dMRI). Many analysis frameworks using dMRI data have been proposed to describe exchange, often using a double diffusion encoding (DDE) stimulated echo sequence. Techniques such as diffusion exchange weighted imaging (DEWI) and the filter exchange and rapid exchange models, use a specific subset of the full space DDE signal. In this work, a general representation of the DDE signal was employed with different sampling schemes (namely constant <span><math><mrow><msub><mi>b</mi><mn>1</mn></msub></mrow></math></span>, diagonal and anti-diagonal) from the data reduction models to estimate exchange. A near-uniform sampling scheme was proposed and compared with the other sampling schemes. The filter exchange and rapid exchange models were also applied to estimate exchange with their own subsampling schemes. These subsampling schemes and models were compared on both simulated data and experimental data acquired with a benchtop MR scanner. In synthetic data, the diagonal and near-uniform sampling schemes performed the best due to the consistency of their estimates with the ground truth. In experimental data, the shifted diagonal and near-uniform sampling schemes outperformed the others, yielding the most consistent estimates with the full space estimation. The results suggest the feasibility of measuring exchange using a general representation of the DDE signal along with variable sampling schemes. In future studies, algorithms could be further developed for the optimization of sampling schemes, as well as incorporating additional properties, such as geometry and diffusion anisotropy, into exchange frameworks.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 3","pages":"Pages 232-247"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48864052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional group resolved NMR relaxation of 3-carbon adsorbates in mesoporous alumina 3-碳吸附质在介孔氧化铝中的官能团分辨NMR弛豫

Magnetic Resonance Letters Pub Date : 2023-08-01 DOI: 10.1016/j.mrl.2023.05.001

Neil Robinson , Carmine D’Agostino , Michael L. Johns

引用次数: 0

A potential NMR-based wettability index using free induction decay for rocks 一种潜在的基于核磁共振的岩石自由感应衰减润湿性指标

Magnetic Resonance Letters Pub Date : 2023-08-01 DOI: 10.1016/j.mrl.2023.03.010

Can Liang , Zijian Jia , Lizhi Xiao , Guwen Wang , Yan Mao , Xiaopeng Ma

{"title":"A potential NMR-based wettability index using free induction decay for rocks","authors":"Can Liang , Zijian Jia , Lizhi Xiao , Guwen Wang , Yan Mao , Xiaopeng Ma","doi":"10.1016/j.mrl.2023.03.010","DOIUrl":"10.1016/j.mrl.2023.03.010","url":null,"abstract":"<div><p>The wettability of reservoir rocks saturated with oil and water is one of the most important factors influencing petrophysics and oil recovery. Minerals with different wettability constitute the overall heterogeneous wettability in rocks. Variations in sample composition can be detected by nuclear magnetic resonance (NMR) measurements. In this paper, the method of using the magnetic susceptibility contrast between rock skeleton and saturated fluid to estimate wettability is proposed. The theoretical feasibility was firstly analyzed, and then the internal gradients caused by magnetic susceptibility contrasts were employed to interpret wettability alteration before and after ageing process in rocks. It was discovered that water and oil in the same pores experienced different internal gradients after ageing, which were associated with the differences in magnetic susceptibility contrasts. After that, the free induction decay measurement was performed to acquire magnetic susceptibility contrasts of artificial sandstone samples with the intermediate-wet condition. A refined NMR wettability index was presented and correlated with the Amott wettability tests. The experimental results demonstrate that the new method for determining wettability is feasible.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 3","pages":"Pages 266-275"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47443662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The NMR core analyzing tomograph: a multi-functional tool for non-destructive testing of building materials 核磁共振核磁共振层析仪:一种用于建筑材料无损检测的多功能工具

Magnetic Resonance Letters Pub Date : 2023-08-01 DOI: 10.1016/j.mrl.2023.03.004

Sabine Kruschwitz , Sarah Munsch , Melissa Telong , Wolfram Schmidt , Thilo Bintz , Matthias Fladt , Ludwig Stelzner

{"title":"The NMR core analyzing tomograph: a multi-functional tool for non-destructive testing of building materials","authors":"Sabine Kruschwitz , Sarah Munsch , Melissa Telong , Wolfram Schmidt , Thilo Bintz , Matthias Fladt , Ludwig Stelzner","doi":"10.1016/j.mrl.2023.03.004","DOIUrl":"10.1016/j.mrl.2023.03.004","url":null,"abstract":"<div><p>NMR is becoming increasingly popular for the investigation of building materials as it is a non-invasive technology that does not require any sample preparation nor causes damage to the material. Depending on the specific application it can offer insights into properties like porosity and spatial saturation degree as well as pore structure. Moreover it enables the determination of moisture transport properties and the (re-)distribution of internal moisture into different reservoirs or chemical phases upon damage and curing. However, as yet most investigations were carried out using devices originally either designed for geophysical applications or the analysis of rather homogeneous small scale (< 10 mL) samples. This paper describes the capabilities of an NMR tomograph, which has been specifically optimized for the investigation of larger, heterogeneous building material samples (diameters of up to 72 mm, length of up to 700 mm) with a high flexibility due to interchangeable coils allowing for a high SNR and short echo times (50–80 μs).</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 3","pages":"Pages 207-219"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41352377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Dipolar NMR relaxation of adsorbates on surfaces of controlled wettability 控制润湿性表面上吸附物的偶极核磁共振弛豫

Magnetic Resonance Letters Pub Date : 2023-08-01 DOI: 10.1016/j.mrl.2023.02.001

Siegfried Stapf , Igor Shikhov , Christoph Arns , Bulat Gizatullin , Carlos Mattea

{"title":"Dipolar NMR relaxation of adsorbates on surfaces of controlled wettability","authors":"Siegfried Stapf , Igor Shikhov , Christoph Arns , Bulat Gizatullin , Carlos Mattea","doi":"10.1016/j.mrl.2023.02.001","DOIUrl":"10.1016/j.mrl.2023.02.001","url":null,"abstract":"<div><p>In reservoir rocks, the term “ageing” refers to extended exposition to crude oil; a typically water-wet sandstone will then gradually become oil-wet as a consequence of the deposition of insoluble fractions of oil onto the surface grains. Rocks have been aged artificially by subjecting them to a bitumen solution at elevated temperature in order to achieve comparable surface properties for three different types of rock: Bentheimer, Berea Buff and Liège Chalk. Using saturated and aromatic model compounds as proxies for crude oil, the nuclear magnetic resonance (NMR) relaxation dispersion in native and aged rocks was compared and correlated to the properties of paramagnetic impurities in these rock types. Perfluorated liquids were found to follow the same trend as deuterated and naturally occurring oil components, suggesting they can be used as suitable tracers for wettability studies since the <sup>19</sup>F nucleus is absent in natural sources. By combining electron paramagnetic resonance (EPR) and dynamic nuclear polarization (DNP) it becomes possible to identify and quantify the origin of the dominating relaxation processes between native and aged rocks, providing an alternative approach to assess wettability in natural rocks.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 3","pages":"Pages 220-231"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42423869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Diffusivity-limited q-space trajectory imaging 扩散率受限q空间轨迹成像

Magnetic Resonance Letters Pub Date : 2023-05-01 DOI: 10.1016/j.mrl.2022.12.003

Deneb Boito , Magnus Herberthson , Tom Dela Haije , Ida Blystad , Evren Özarslan

引用次数: 0

Data inversion of multi-dimensional magnetic resonance in porous media 多孔介质中多维磁共振的数据反演

Magnetic Resonance Letters Pub Date : 2023-05-01 DOI: 10.1016/j.mrl.2023.03.003

Fangrong Zong , Huabing Liu , Ruiliang Bai , Petrik Galvosas

{"title":"Data inversion of multi-dimensional magnetic resonance in porous media","authors":"Fangrong Zong , Huabing Liu , Ruiliang Bai , Petrik Galvosas","doi":"10.1016/j.mrl.2023.03.003","DOIUrl":"10.1016/j.mrl.2023.03.003","url":null,"abstract":"<div><p>Since its inception in the 1970s, multi-dimensional magnetic resonance (MR) has emerged as a powerful tool for non-invasive investigations of structures and molecular interactions. MR spectroscopy beyond one dimension allows the study of the correlation, exchange processes, and separation of overlapping spectral information. The multi-dimensional concept has been re-implemented over the last two decades to explore molecular motion and spin dynamics in porous media. Apart from Fourier transform, methods have been developed for processing the multi-dimensional time-domain data, identifying the fluid components, and estimating pore surface permeability via joint relaxation and diffusion spectra. Through the resolution of spectroscopic signals with spatial encoding gradients, multi-dimensional MR imaging has been widely used to investigate the microscopic environment of living tissues and distinguish diseases. Signals in each voxel are usually expressed as multi-exponential decay, representing microstructures or environments along multiple pore scales. The separation of contributions from different environments is a common ill-posed problem, which can be resolved numerically. Moreover, the inversion methods and experimental parameters determine the resolution of multi-dimensional spectra. This paper reviews the algorithms that have been proposed to process multi-dimensional MR datasets in different scenarios. Detailed information at the microscopic level, such as tissue components, fluid types and food structures in multi-disciplinary sciences, could be revealed through multi-dimensional MR.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 2","pages":"Pages 127-139"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49475785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Solid-state NMR spectroscopy at ultrahigh resolution for structural and dynamical studies of MOFs 用于MOFs结构和动力学研究的超高分辨率固态NMR光谱

Magnetic Resonance Letters Pub Date : 2023-05-01 DOI: 10.1016/j.mrl.2023.02.002

Qing Wang , Min Peng , Cong-Cong Liang , Jing Tan , Sophia Zhang , Yue-Biao Zhang , Haiming Liu

{"title":"Solid-state NMR spectroscopy at ultrahigh resolution for structural and dynamical studies of MOFs","authors":"Qing Wang , Min Peng , Cong-Cong Liang , Jing Tan , Sophia Zhang , Yue-Biao Zhang , Haiming Liu","doi":"10.1016/j.mrl.2023.02.002","DOIUrl":"10.1016/j.mrl.2023.02.002","url":null,"abstract":"<div><p>To characterize the structure and dynamics of metal–-organic frameworks (MOFs) in-depth at the molecular level, it is necessary to pursue high-resolution solid-state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. Spectral resolution is usually affected by the quality of materials and various experimental conditions, of which magic angle (MA) accuracy is a crucial determinant. The current industrial criteria for MA calibration based on the common standard of KBr were found insufficient in guaranteeing optimal resolution MAS NMR for highly ordered MOFs. To drive towards higher-resolution MAS NMR spectroscopy, we propose a calibration protocol for more accurate MA with a higher-precision criterion based on <sup>79</sup>Br MAS NMR of KBr, where the linewidth ratio of the fifth-order spinning sideband to the central band of KBr should be less than 1.00. As a result, ultrahigh-resolution <sup>13</sup>C cross-polarization (CP) MAS NMR of MOF-5 is achieved with minimal linewidths as low as 4 Hz, and therefore MOF-5 can be used as a new standard convenient for verifying MA accuracy and also optimizing <sup>13</sup>C CP conditions. Maintaining high-precision MA under variable temperature (VT) was found challenging on certain commercial MAS NMR probes, as was systematically investigated by VT NMR using KBr and MOF-5. Nevertheless, ultrahigh-resolution MAS NMR spectroscopy with stable MA under VT is employed to reveal fine structures and linker dynamics of a series of Zn-based MOFs with highly regulated structures. The ultrahigh-resolution NMR methodcan be generally applied to study a broad range of MOFs and other materials.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 2","pages":"Pages 175-186"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43458575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advanced surface coil layout with intrinsic noise cancellation properties for surface-NMR applications 先进的表面线圈布局，具有内在的噪声消除特性，用于表面核磁共振应用

Magnetic Resonance Letters Pub Date : 2023-05-01 DOI: 10.1016/j.mrl.2023.03.008

Thomas Hiller , Stephan Costabel , Raphael Dlugosch , Tobias Splith , Mike Müller-Petke

{"title":"Advanced surface coil layout with intrinsic noise cancellation properties for surface-NMR applications","authors":"Thomas Hiller , Stephan Costabel , Raphael Dlugosch , Tobias Splith , Mike Müller-Petke","doi":"10.1016/j.mrl.2023.03.008","DOIUrl":"10.1016/j.mrl.2023.03.008","url":null,"abstract":"<div><p>A recent study demonstrated that in small-scale prepolarized surface nuclear magnetic resonance (SNMR-PP) measurements with a footprint of a few square meters, customized PP switch-off ramps can serve as an efficient excitation mechanism, eliminating the requirement for a conventional oscillating excitation pulse. This approach enables the detection of short relaxation signals from the unsaturated soil zone and can, therefore, be used to directly provide soil moisture and pore geometry information. Because ultimately such small-scale SNMR-PP setups are intended for a mobile application, it is necessary to develop strategies that allow for speedy measurement progress and do not require noise cancellation protocols based on reference stations. Hence, we developed a new concentric figure-of-eight (cFOE) loop layout that combines the direction independence of a circular loop with the intrinsic noise cancellation properties of a classical FOE-loop. This approach significantly decreases the measurement time because suitable signal-to-noise ratios are reached much faster compared to a classical circular loop and will bring us one step further toward fast and non-invasive soil moisture mapping applications.</p></div>","PeriodicalId":93594,"journal":{"name":"Magnetic Resonance Letters","volume":"3 2","pages":"Pages 140-149"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48047487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1