Journal of Applied Crystallography最新文献_第3页

Velocity gradient dependent structures of 12-2-12 wormlike micelles: insights from small-angle neutron scattering in the 1-2 shear plane. 基于速度梯度的12-2-12虫状胶束结构：来自1-2剪切面小角中子散射的见解。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-29 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725006521

Hiroki Iwase, Shin-Ichi Takata, Toshiaki Morikawa, Tomokazu Yoshimura

{"title":"Velocity gradient dependent structures of 12-2-12 wormlike micelles: insights from small-angle neutron scattering in the 1-2 shear plane.","authors":"Hiroki Iwase, Shin-Ichi Takata, Toshiaki Morikawa, Tomokazu Yoshimura","doi":"10.1107/S1600576725006521","DOIUrl":"10.1107/S1600576725006521","url":null,"abstract":"The velocity gradient dependent shear-induced structural evolution of wormlike micelles (WLMs) formed by a gemini-type cationic surfactant (12-2-12) in an aqueous solution was investigated using small-angle neutron scattering (SANS). To achieve this, a cell for observation in the velocity-velocity gradient (1-2) shear plane was constructed. SANS measurements were conducted at multiple positions across the gap of this 1-2 shear cell under various shear rates, covering both shear-thickening and shear-thinning regimes. During shear thickening at apparent shear rates of 70-200 s-1, a clear position-dependent alignment of WLMs was observed, with higher orientation near the rotor. In contrast, the intermicellar distance remained largely uniform across the gap. Neutron transmission measurements indicated no significant macroscopic concentration fluctuations. These results suggest that shear thickening is primarily driven by shear-induced micellar elongation and orientation, rather than the formation of concentration fluctuations. This study indicates the utility of SANS measurements in the 1-2 shear plane in revealing spatially resolved structural details, providing crucial insights into the 3D behavior of complex fluids under shear and complementing previous Rheo-SANS findings.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1407-1416"},"PeriodicalIF":2.8,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321015/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fundamental motifs and parity within the crystallographic point groups. 晶体学点群中的基本母基和宇称。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-29 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725005631

Maureen M Julian, Matthew Macauley

{"title":"Fundamental motifs and parity within the crystallographic point groups.","authors":"Maureen M Julian, Matthew Macauley","doi":"10.1107/S1600576725005631","DOIUrl":"10.1107/S1600576725005631","url":null,"abstract":"This paper analyzes the Hasse diagram, or family tree, of the 3D crystal classes, also called geometric crystal classes. The 32 point-group classes are partitioned into seven crystal systems. In this paper, the structures of these systems are analyzed, leading to a new understanding of the relationships among and within them. The point groups, including their subgroups up to conjugacy, appear in six structural motifs in the Hasse diagram or family tree. Each motif has a parity - even or odd - that determines its structure. In three dimensions, the odd motifs are called monads, trigonals and cubics, and the even motifs are called dyads, tetragonals and hexagonals. Of the 32 classes of 3D point groups, 29 have a well defined parity, in that they appear in either an even or an odd motif. In contrast, the three monoclinic point groups are 'ambidextrous', in that they appear in two motifs, one of each parity. An analysis of the ten 2D point groups reveals an analogous structure, except for the presence of an ambidextrous crystal system. The striking structural uniformity of the motifs across the Hasse diagram confirms that they are essential building blocks of the crystallographic point groups.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1447-1454"},"PeriodicalIF":2.8,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321018/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-energy diffuse X-ray scattering at ultra-small-angle grazing incidence for local structure study of single-crystalline thin films. 超小角掠入射高能漫射x射线散射在单晶薄膜局部结构研究中的应用。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-29 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725005837

Joohee Bang, Nives Strkalj, Martin F Sarott, Yevheniia Kholina, Morgan Trassin, Thomas Weber

引用次数: 0

On the use of beam precession for serial electron crystallography. 束流进动在连续电子晶体学中的应用。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-25 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725005606

Sergi Plana-Ruiz, Penghan Lu, Govind Ummethala, Rafal E Dunin-Borkowski

{"title":"On the use of beam precession for serial electron crystallography.","authors":"Sergi Plana-Ruiz, Penghan Lu, Govind Ummethala, Rafal E Dunin-Borkowski","doi":"10.1107/S1600576725005606","DOIUrl":"10.1107/S1600576725005606","url":null,"abstract":"During the past few years, serial electron crystallography (serial electron diffraction) has been gaining attention for the structure determination of crystalline compounds that are sensitive to irradiation by an electron beam. By recording a single electron diffraction pattern per crystal, indexing thousands to tens of thousands of such patterns and merging the reflection intensities of the successfully indexed patterns, one can retrieve crystal structure models with strongly mitigated beam damage contributions. However, one of the technique's bottlenecks is the need to obtain so many well indexed diffraction patterns, which leads to the collection of raw diffraction data in an automated way that usually yields low indexing rates. This work demonstrates how to overcome this limitation by performing the serial crystallography experiment following a semi-automated routine with a precessed electron beam (serial precession electron diffraction). The precession movement increases the number of reflections present in the diffraction patterns, and dynamical effects related to specific orientations of the crystals with respect to the electron beam are greatly minimized. This leads to more uniform reflection intensities across the serial data set, and a smaller number of patterns are required to merge the reflection intensities for good statistics. Furthermore, structure refinements based on the dynamical diffraction theory become possible due to the diffraction volume integration of beam precession, providing a novel approach for more accurate structure models. In this context, the use of beam precession is presented as an advantageous tool for serial electron crystallography, as it enables reliable crystal structure analysis with a lower amount of diffraction data.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1249-1260"},"PeriodicalIF":2.8,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321033/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inversion of the X-ray restrained wavefunction equations: a first step towards the development of exchange-correlation functionals based on X-ray data. x射线约束波函数方程的反演：基于x射线数据的交换相关函数发展的第一步。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-25 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725004765

Alessandro Genoni, Maurizio Sironi

{"title":"Inversion of the X-ray restrained wavefunction equations: a first step towards the development of exchange-correlation functionals based on X-ray data.","authors":"Alessandro Genoni, Maurizio Sironi","doi":"10.1107/S1600576725004765","DOIUrl":"10.1107/S1600576725004765","url":null,"abstract":"The X-ray restrained wavefunction (XRW) method is a quantum crystallographic technique that enables the determination of wavefunctions compatible with experimental X-ray diffraction data. Extensive research has demonstrated that this strategy inherently captures electron correlation and polarization effects on the electron density, while also providing consistent electron distributions. These findings suggest that the approach could be valuable in the development of new exchange-correlation (xc) functionals for density functional theory (DFT) calculations. This is particularly relevant in light of recent observations and recommendations by Medvedev et al. [Science (2017), 355, 49-52], who stressed the importance that xc functionals give both accurate energy values and exact electron densities, in line with the original spirit of DFT. Motivated by this perspective, this paper presents a preliminary investigation that aims at extracting and visualizing for the first time the perturbation potentials arising from the use of X-ray diffraction data as restraints in XRW calculations. In the present work, these potentials are simply obtained as orbital-averaged potentials through straightforward inversions of the XRW equations, where theoretical or high-quality experimental X-ray structure factors are employed in XRW computations at the restricted Hartree-Fock level for atoms (neon, argon and krypton) and simple molecules (dilithium and urea). Features and limitations of the resulting preliminary potentials are illustrated, while future perspectives on the use of the XRW method for the development of xc functionals are also discussed.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1106-1121"},"PeriodicalIF":2.8,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321031/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Opportunities for near-surface small-angle neutron scattering to probe magnetic nanostructures within thin-film volumes. 近表面小角中子散射探测薄膜内磁性纳米结构的机会。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-22 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725005503

Grace L Causer

{"title":"Opportunities for near-surface small-angle neutron scattering to probe magnetic nanostructures within thin-film volumes.","authors":"Grace L Causer","doi":"10.1107/S1600576725005503","DOIUrl":"10.1107/S1600576725005503","url":null,"abstract":"Near-surface small-angle neutron scattering (NS-SANS) is a highly versatile, yet under-utilized, technique in condensed matter research. It addresses the shortcomings of transmission SANS to enable the characterization of nano-structures within extremely small sample volumes in the thin-film limit. NS-SANS stands out in its capacity to resolve 1D, 2D or 3D structural, chemical and magnetic correlations beneath the surfaces of thin films with nanometre resolution. By varying the incident angle above the critical angle of reflection, NS-SANS delivers tuneable depth sensitivity across nano-confined volumes, effectively minimizing noise contributions from substrates while surpassing the surface-sensitive capabilities of grazing-incidence SANS. This perspective highlights the future potential of NS-SANS to study condensed matter thin films and heterostructures, with a special focus on nanoscale magnetic phenomena, such as topological skyrmion lattices, superconducting vortex lattices and chiral domain walls, which are of timely interest to the magnetism and quantum materials communities.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1455-1461"},"PeriodicalIF":2.8,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321037/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Powder diffraction data beyond the pattern: a practical review. 粉末衍射数据超越模式：实用回顾。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-22 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725004728

Nicola Casati, Elena Boldyreva

引用次数: 0

A systematic approach for quantitative orientation and phase fraction analysis of thin films through grazing-incidence X-ray diffraction. 用掠入射x射线衍射分析薄膜定量取向和相分数的系统方法。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-22 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725004935

Fabian Gasser, Sanjay John, Jorid Smets, Josef Simbrunner, Mario Fratschko, Víctor Rubio-Giménez, Rob Ameloot, Hans-Georg Steinrück, Roland Resel

{"title":"A systematic approach for quantitative orientation and phase fraction analysis of thin films through grazing-incidence X-ray diffraction.","authors":"Fabian Gasser, Sanjay John, Jorid Smets, Josef Simbrunner, Mario Fratschko, Víctor Rubio-Giménez, Rob Ameloot, Hans-Georg Steinrück, Roland Resel","doi":"10.1107/S1600576725004935","DOIUrl":"10.1107/S1600576725004935","url":null,"abstract":"Grazing-incidence X-ray diffraction (GIXD) is widely used for the structural characterization of thin films, particularly for analyzing phase composition and the orientation distribution of crystallites. While various tools exist for qualitative evaluation, a widely applicable systematic procedure to obtain quantitative information has not yet been developed. This work presents a first step in that direction, allowing accurate quantitative information to be obtained through the evaluation of radial line profiles from GIXD data. An algorithm is introduced for computing radial line profiles based on the crystal structure of known compounds. By fitting experimental data with calculated line profiles, accurate quantitative information about orientation distribution and phase composition is obtained, along with additional parameters such as mosaicity and total crystal volume. The approach is demonstrated using three distinct thin film systems, highlighting the broad applicability of the algorithm. This method provides a systematic and general approach to obtaining quantitative information from GIXD data.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1288-1298"},"PeriodicalIF":2.8,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321010/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Small-angle X-ray scattering profile calculation for high-resolution models of biomacromolecules. 高分辨率生物大分子模型的小角度x射线散射剖面计算。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-16 eCollection Date: 2025-08-01 DOI: 10.1107/S160057672500562X

Kristian Lytje, Jan Skov Pedersen

{"title":"Small-angle X-ray scattering profile calculation for high-resolution models of biomacromolecules.","authors":"Kristian Lytje, Jan Skov Pedersen","doi":"10.1107/S160057672500562X","DOIUrl":"10.1107/S160057672500562X","url":null,"abstract":"We introduce a new approach to calculating small-angle X-ray scattering (SAXS) profiles from high-resolution atomic structures, which is realized in the open-source software AUSAXS. We employ an efficient implementation of the Debye equation, incorporating both accurate excluded volume models and a novel hydration shell model based on explicit dummy atoms. Two new excluded volume models are presented: (i) a simple, heterogeneous equivalent atom model, and (ii) a grid-based model. The two approaches reduce the risk of overfitting by either eliminating fitting parameters or introducing a safer volume scaling method. These models are compared with the traditional Gaussian sphere method, which is widely used in existing software. The comparisons reveal significant shortcomings in previously accepted methods, suggesting they may be more prone to overfitting than previously thought. This underscores the importance of a well tested and openly accessible baseline implementation like AUSAXS. AUSAXS is freely available at https://github.com/AUSAXS/AUSAXS.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"58 Pt 4","pages":"1332-1346"},"PeriodicalIF":2.8,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12321023/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144789145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Superstability of micrometre jets surrounded by a polymeric shell. 被聚合外壳包围的微米射流的超稳定性。

IF 2.8 3区材料科学

Journal of Applied Crystallography Pub Date : 2025-07-16 eCollection Date: 2025-08-01 DOI: 10.1107/S1600576725004790

A Rubio, J M Montanero, M Vakili, F H M Koua, S Bajt, H N Chapman, A M Gañán-Calvo

引用次数: 0