{"title":"Introduction to the special issue related to the 18th International Small Angle Scattering Conference (SAS2022)","authors":"Florian Meneau, Jill Trewhella, Jan Ilavsky","doi":"10.1107/s1600576723010348","DOIUrl":"https://doi.org/10.1107/s1600576723010348","url":null,"abstract":"A new virtual special issue highlights some of the most exciting work presented at the 18th International Small Angle Scattering Conference (SAS2022), which took place in Campinas, Brazil. The articles included here were originally published in recent regular issues of <i>Journal of Applied Crystallography</i> and <i>Acta Crystallographica Section D</i>. The SAS2022 special issue is available at http://journals.iucr.org/special_issues/2023/sas2022/.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"6 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138535899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander, A., Pohlmann, T., Hoppe, M., Röh, J., Gutowski, O., Küpper, K., Bertram, F., Wollschläger, J.
{"title":"Time-resolved high-energy X-ray diffraction studies of ultrathin Ni ferrite films on MgO(001)","authors":"Alexander, A., Pohlmann, T., Hoppe, M., Röh, J., Gutowski, O., Küpper, K., Bertram, F., Wollschläger, J.","doi":"10.1107/s1600576723009287","DOIUrl":"https://doi.org/10.1107/s1600576723009287","url":null,"abstract":"","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"41 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138535900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
de la Flor, G., Kroumova, E., Hanson, R.M., Aroyo, M.I.
{"title":"The International Tables Symmetry Database","authors":"de la Flor, G., Kroumova, E., Hanson, R.M., Aroyo, M.I.","doi":"10.1107/s1600576723009068","DOIUrl":"https://doi.org/10.1107/s1600576723009068","url":null,"abstract":"The International Tables Symmetry Database (https://symmdb.iucr.org/), which is part of International Tables for Crystallography, is a collection of individual databases of crystallographic space-group and point-group information with associated programs. The programs let the user access and in some cases interactively visualize the data, and some also allow new data to be calculated `on the fly'. Together these databases and programs expand upon and complement the symmetry information provided in International Tables for Crystallography Volume A, Space-Group Symmetry, and Volume A1, Symmetry Relations between Space Groups. The Symmetry Database allows users to learn about and explore the space and point groups, and facilitates the study of group–subgroup relations between space groups, with applications in determining crystal-structure relationships, in studying phase transitions and in domain-structure analysis. The use of the International Tables Symmetry Database in all these areas is demonstrated using several examples.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"7 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138535901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Munoz, P., Ilavsky, J., Newville, M., Wetter, N.U., Lourenço, R.A., Barbosa de Andrade, M., Martins, T.S., Dipold, J., Freitas, A.Z., Cides da Silva, L.C., Oliveira, C.L.P.
{"title":"(U)SAXS characterization of porous microstructure of chert: insights into organic matter preservation","authors":"Munoz, P., Ilavsky, J., Newville, M., Wetter, N.U., Lourenço, R.A., Barbosa de Andrade, M., Martins, T.S., Dipold, J., Freitas, A.Z., Cides da Silva, L.C., Oliveira, C.L.P.","doi":"10.1107/s1600576723008889","DOIUrl":"https://doi.org/10.1107/s1600576723008889","url":null,"abstract":"This study characterizes the microstructure and mineralogy of 132 (ODP sample), 1000 and 1880 million-year-old chert samples. By using ultra-small-angle X-ray scattering (USAXS), wide-angle X-ray scattering and other techniques, the preservation of organic matter (OM) in these samples is studied. The scarce microstructural data reported on chert contrast with many studies addressing porosity evolution in other sedimentary rocks. The aim of this work is to solve the distribution of OM and silica in chert by characterizing samples before and after combustion to pinpoint the OM distribution inside the porous silica matrix. The samples are predominantly composed of alpha quartz and show increasing crystallite sizes up to 33 ± 5 nm (1σ standard deviation or SD). In older samples, low water abundances (∼0.03%) suggest progressive dehydration. (U)SAXS data reveal a porous matrix that evolves over geological time, including, from younger to older samples, (1) a decreasing pore volume down to 1%, (2) greater pore sizes hosting OM, (3) decreasing specific surface area values from younger (9.3 ± 0.1 m2 g−1) to older samples (0.63 ± 0.07 m2 g−1, 1σ SD) and (4) a lower background intensity correlated to decreasing hydrogen abundances. The pore-volume distributions (PVDs) show that pores ranging from 4 to 100 nm accumulate the greater volume fraction of OM. Raman data show aromatic organic clusters up to 20 nm in older samples. Raman and PVD data suggest that OM is located mostly in mesopores. Observed structural changes, silica–OM interactions and the hydrophobicity of the OM could explain the OM preservation in chert.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"13 5 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138535902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brian R. Pauw, Glen J. Smales, Andy S. Anker, Daniel M. Balazs, Frederick L. Beyer, Ralf Bienert, Wim G. Bouwman, Ingo Breßler, Joachim Breternitz, Erik S Brok, Gary Bryant, Andrew J. Clulow, Erin R. Crater, Frédéric De Geuser, Alessandra del Giudice, Jérôme Deumer, Sabrina Disch, Shankar Dutt, Kilian Frank, Emiliano Fratini, Elliot P. Gilbert, Marc Benjamin Hahn, James Hallett, Max Hohenschutz, Martin Hollamby, Steven Huband, Jan Ilavsky, Johanna K. Jochum, Mikkel Juelsholt, Bradley W. Mansel, Paavo Penttilä, Rebecca K. Pittkowski, Giuseppe Portale, Lilo D. Pozzo, Paulo Ricardo de Abreu Furtado Garcia, Leonhard Rochels, Julian M. Rosalie, Patrick E. J. Saloga, Susanne Seibt, Andrew J. Smith, Gregory N. Smith, Venkatasamy Annadurai, Glenn A. Spiering, Tomasz M. Stawski, Olivier Taché, Andreas F. Thünemann, Kristof Toth, Andrew E. Whitten, Joachim Wuttke
{"title":"The human factor: results of a small-angle scattering data analysis round robin","authors":"Brian R. Pauw, Glen J. Smales, Andy S. Anker, Daniel M. Balazs, Frederick L. Beyer, Ralf Bienert, Wim G. Bouwman, Ingo Breßler, Joachim Breternitz, Erik S Brok, Gary Bryant, Andrew J. Clulow, Erin R. Crater, Frédéric De Geuser, Alessandra del Giudice, Jérôme Deumer, Sabrina Disch, Shankar Dutt, Kilian Frank, Emiliano Fratini, Elliot P. Gilbert, Marc Benjamin Hahn, James Hallett, Max Hohenschutz, Martin Hollamby, Steven Huband, Jan Ilavsky, Johanna K. Jochum, Mikkel Juelsholt, Bradley W. Mansel, Paavo Penttilä, Rebecca K. Pittkowski, Giuseppe Portale, Lilo D. Pozzo, Paulo Ricardo de Abreu Furtado Garcia, Leonhard Rochels, Julian M. Rosalie, Patrick E. J. Saloga, Susanne Seibt, Andrew J. Smith, Gregory N. Smith, Venkatasamy Annadurai, Glenn A. Spiering, Tomasz M. Stawski, Olivier Taché, Andreas F. Thünemann, Kristof Toth, Andrew E. Whitten, Joachim Wuttke","doi":"10.1107/s1600576723008324","DOIUrl":"https://doi.org/10.1107/s1600576723008324","url":null,"abstract":"A round-robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5% and half of the population width entries within 40%. Due to the added complexity of the structure factor, far fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 and 86%, respectively. This round-robin experiment highlights several causes for the discrepancies, for which solutions are proposed.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135768827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New features of the <i>RootProf</i> program for model-free analysis of unidimensional profiles","authors":"Annamaria Mazzone, Mattia Lopresti, Benny Danilo Belviso, Rocco Caliandro","doi":"10.1107/s1600576723008348","DOIUrl":"https://doi.org/10.1107/s1600576723008348","url":null,"abstract":"The RootProf computer program applies multivariate model-free analysis to crystallographic data and to any x , y experimental data in general. It has been enhanced with several new features, including a graphical user interface, multithreading implementation and additional pre-processing options. The program also includes novel qualitative analysis methods, such as semiquantitative estimates derived from principal component analysis (PCA) and restrained PCA to extract the diffraction signal from active atoms. Additional quantitative analysis methods have been included, involving the combination of different datasets or the application of the standard addition method as well as tools for crystallinity analysis, kinetic analysis and extraction of free crystal cell parameters from a pair distribution function profile. The ROOT data analysis framework supports the program and can be installed on the current major platforms such as Windows, Linux and Mac OSX with detailed user documentation included. Applications of the new developments are presented and discussed in the paper, and related command files are provided as supporting information.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135617943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Richard D. Harvey, Gianluca Bello, Alexey G. Kikhney, Jaume Torres, Wahyu Surya, Christian Wölk, Chen Shen
{"title":"Absolute scattering length density profile of liposome bilayers obtained by SAXS combined with GIXOS: a tool to determine model biomembrane structure","authors":"Richard D. Harvey, Gianluca Bello, Alexey G. Kikhney, Jaume Torres, Wahyu Surya, Christian Wölk, Chen Shen","doi":"10.1107/s1600576723008439","DOIUrl":"https://doi.org/10.1107/s1600576723008439","url":null,"abstract":"Lipid membranes play an essential role in biology, acting as host matrices for biomolecules like proteins and facilitating their functions. Their structures and structural responses to physiologically relevant interactions ( i.e. with membrane proteins) provide key information for understanding biophysical mechanisms. Hence, there is a crucial need of methods to understand the effects of membrane host molecules on the lipid bilayer structure. Here, a purely experimental method is presented for obtaining the absolute scattering length density profile and the area per lipid of liposomal bilayers, by aiding the analysis of small-angle X-ray scattering (SAXS) data with the volume of bare headgroups obtained from grazing-incidence X-ray off-specular scattering (GIXOS) data of monolayers of the same model membrane lipid composition. The GIXOS data experimentally demonstrate that the variation of the bare headgroup volume upon change in lipid packing density is small enough to allow its usage as a reference value without knowing the lipid packing stage in a bilayer. This approach also has the advantage that the reference volume is obtained in the same aqueous environment as used for the model membrane bilayers. The validity of this method is demonstrated using several typical membrane compositions, as well as one example of a phospholipid membrane with an incorporated transmembrane peptide. This methodology allows us to obtain absolute scale rather than relative scale values using solely X-ray-based instrumentation, retaining a similar resolution to SAXS experiments. The method presented has high potential for understanding the structural effects of membrane proteins on the biomembrane structure.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135618546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dino Aquilano, Marco Bruno, Stefano Ghignone, Linda Pastero
{"title":"Twinning and homoepitaxy cooperation in the already rich growth morphology of CaCO<sub>3</sub> polymorphs. I. Aragonite","authors":"Dino Aquilano, Marco Bruno, Stefano Ghignone, Linda Pastero","doi":"10.1107/s1600576723008208","DOIUrl":"https://doi.org/10.1107/s1600576723008208","url":null,"abstract":"Calcite and aragonite are the two most abundant among the CaCO 3 polymorphs and are also well known for their rich morphology and habit, to which twinning relevantly contributes. Moreover, the calcite → aragonite transformation has been debated for a long time, even though the homo-epitaxies occurring within each polymorph have been overlooked, to date, from both experimental and theoretical points of view. Twinning is common and unfortunately can be deceptive as it can be mistaken for homo-epitaxy, thus leading to confusion regarding the growth mechanisms of many crystal aggregates. Here, experimental and theoretical studies were carried out to investigate the twinning and homo-epitaxy that operate in aragonite: (i) the connection between twinning and homo-epitaxy for contact and penetration aggregates made by the lateral {010} and {110} aragonite forms; (ii) the homo-epitaxial relationships among the {001} pinacoid and both the {010} pinacoid and the prismatic {110} aragonite forms. This work attempts to provide a new approach to monitoring the growth mechanisms of aragonite in cases where it is obtained not as a single crystal but as an aggregate. An analogous problem will be explored in our forthcoming work on calcite.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"48 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135567900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<i>Polynator</i>: a tool to identify and quantitatively evaluate polyhedra and other shapes in crystal structures","authors":"Lukas Link, Rainer Niewa","doi":"10.1107/s1600576723008476","DOIUrl":"https://doi.org/10.1107/s1600576723008476","url":null,"abstract":"Polynator is a Python program capable of identifying coordination polyhedra, molecules and other shapes in crystal structures and evaluating their distortions. Distortions are quantified by fitting the vertices of a model to a selected set of atoms. In contrast to earlier programs, models can be deformable, which allows them to represent a point group or a range of shapes such as the set of all trigonal prisms, rather than a specific, rigid shape such as the equilateral trigonal prism. The program comes with a graphical user interface and is freely available. This paper discusses its working principle and illustrates a number of applications.","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135618685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
