si Hsinchu Titans vs Taiwan Daredevils, Dream11 Prediction: Best picks for HST vs TDR today in Taipei T10 League By www.dnaindia.com Published On :: Sun, 10 May 2020 02:15:00 GMT HST vs TDR Dream11 Team - Check My Dream11 Team, Best players list of today's match, Hsinchu Titans vs Taiwan Daredevils Dream11 Team Player List, TDG Dream11 Team Player List, HST Dream11 Team Player List, Dream11 Guru Tips, Online Cricket Tips, Hsinchu Titans vs Taiwan Daredevils Head to Head. Full Article Sports Cricket
si 'Ye bewakoof kisi aur ko banana': Mohammed Shami recalls instance when MS Dhoni told him off over a bouncer By www.dnaindia.com Published On :: Sun, 10 May 2020 04:42:00 GMT The incident took place back in 2014 during India's test match against New Zealand. Full Article Sports Cricket
si DNA Exclusive: Arti Singh remembers how her first letter to mother brought them closer By www.dnaindia.com Published On :: Sun, 10 May 2020 05:23:00 GMT Arti Singh remembered her first letter to mother on the occasion of Mothers' Day Full Article Entertainment Television
si 'Allow private vehicles to ferry them': Sanjay Raut's advice to Maharashtra govt on migrant situation By www.dnaindia.com Published On :: Sun, 10 May 2020 05:34:00 GMT Sanjay Raut took to his official Twitter handle on Sunday to let know his suggestion via a post regarding the situation. Full Article India
si DNA Exclusive: Sophie Choudry reveals how she would celebrate Mothers' Day with 'super mom' By www.dnaindia.com Published On :: Sun, 10 May 2020 05:40:00 GMT The coronavirus lockdown has separated many of us from our families, including our mothers. However, Sophie Choudhry is one lucky celeb who is able to spend her quarantine and Mothers' Day with her supermom. In fact, she told us all about her plans for the day. Full Article Entertainment Bollywood
si Massive dust storm hits Delhi-NCR; accompanying rains bring relief from summer heat By www.dnaindia.com Published On :: Sun, 10 May 2020 06:40:00 GMT The change in weather and the dust storm was witnessed in areas from Noida to Rajouri Garden in West Delhi. Full Article India
si Not anticipating worst situation, but...: Vardhan By www.rediff.com Published On :: Sat, 09 May 2020 21:49:22 +0530 But still we have prepared the whole country for the worst situation, the Union health minister said. Full Article
si Indian, Chinese troops clash in Sikkim sector By www.rediff.com Published On :: Sun, 10 May 2020 11:52:15 +0530 Many of them sustained minor injuries in the clash near Naku La in the Sikkim sector along the Sino-Indo border on Saturday Full Article
si Tracking US President Donald Trump’s response to Covid-19 through his top 10 quotes By indianexpress.com Published On :: Sat, 09 May 2020 16:22:11 +0000 Full Article World
si TV Rewind | Desperate Housewives: Gossip Girl for grown-ups By indianexpress.com Published On :: Sat, 09 May 2020 20:38:07 +0000 Full Article Entertainment Television
si Happy Mother’s Day: Five iconic moms of Indian television By indianexpress.com Published On :: Sun, 10 May 2020 02:50:27 +0000 Full Article Entertainment Television
si Chandigarh: Bapu dham resident tests positive after death, UT sees 21 new cases By indianexpress.com Published On :: Sat, 09 May 2020 20:40:20 +0000 Full Article Chandigarh Cities
si Panchkula: Cook at police dept tests positive By indianexpress.com Published On :: Sat, 09 May 2020 20:41:45 +0000 Full Article Chandigarh Cities
si Random sampling finds two positive cases in two days in Panchkula By indianexpress.com Published On :: Sat, 09 May 2020 20:43:31 +0000 Full Article Chandigarh Cities
si Punjab: Balbir Singh Senior admitted to a private hospital due to pneumonia By indianexpress.com Published On :: Sat, 09 May 2020 20:47:52 +0000 Full Article Chandigarh Cities
si Inside Track: Kishor’s expertise By indianexpress.com Published On :: Sat, 09 May 2020 18:46:34 +0000 Full Article Columns Opinion
si Designer Neeta Lulla recalls creating Juhi’s look in 2.5 hours for the movie Darr By indianexpress.com Published On :: Sat, 09 May 2020 15:02:06 +0000 Full Article Fashion Lifestyle
si Narco-terrorist with K-group links held in Sirsa By timesofindia.indiatimes.com Published On :: Sun, 10 May 2020 05:50:54 IST Three people, including two brothers running a narco terrorism network linked to Hizbul Mujahideen commander Naikoo, who was killed by security forces in Kashmir recently, were on Saturday arrested in a joint operation conducted by Haryana Police, National Investigation Agency (NIA) and Punjab Police. Full Article
si UFC cuts bout after fighter tests positive for coronavirus By indianexpress.com Published On :: Sun, 10 May 2020 03:24:27 +0000 Full Article Sport Others Sports
si Mother’s Day: 5 apps that can make a mother’s life easier By indianexpress.com Published On :: Sun, 10 May 2020 03:59:43 +0000 Full Article Technology Techook
si Crossing final hurdle in World Cups down to experience and preparation: Anjum Chopra By indianexpress.com Published On :: Sat, 09 May 2020 14:35:48 +0000 Full Article Cricket Sports
si ‘Focussing on mental state, can pick up from where I left’: Virat Kohli By indianexpress.com Published On :: Sat, 09 May 2020 16:47:25 +0000 Full Article Cricket Sports
si Device for source position stabilization and beam parameter monitoring at inverse Compton X-ray sources By scripts.iucr.org Published On :: 2019-08-07 Compact X-ray sources based on inverse Compton scattering provide brilliant and partially coherent X-rays in a laboratory environment. The cross section for inverse Compton scattering is very small, requiring high-power laser systems as well as small laser and electron beam sizes at the interaction point to generate sufficient flux. Therefore, these systems are very sensitive to distortions which change the overlap between the two beams. In order to monitor X-ray source position, size and flux in parallel to experiments, the beam-position monitor proposed here comprises a small knife edge whose image is acquired with an X-ray camera specifically designed to intercept only a very small fraction of the X-ray beam. Based on the source position drift recorded with the monitor, a closed-loop feedback stabilizes the X-ray source position by adjusting the laser beam trajectory. A decrease of long-term source position drifts by more than one order of magnitude is demonstrated with this device. Consequently, such a closed-loop feedback system which enables stabilization of source position drifts and flux of inverse Compton sources in parallel to experiments has a significant impact on the performance of these sources. Full Article text
si A versatile nanoreactor for complementary in situ X-ray and electron microscopy studies in catalysis and materials science By scripts.iucr.org Published On :: 2019-08-27 Two in situ `nanoreactors' for high-resolution imaging of catalysts have been designed and applied at the hard X-ray nanoprobe endstation at beamline P06 of the PETRA III synchrotron radiation source. The reactors house samples supported on commercial MEMS chips, and were applied for complementary hard X-ray ptychography (23 nm spatial resolution) and transmission electron microscopy, with additional X-ray fluorescence measurements. The reactors allow pressures of 100 kPa and temperatures of up to 1573 K, offering a wide range of conditions relevant for catalysis. Ptychographic tomography was demonstrated at limited tilting angles of at least ±35° within the reactors and ±65° on the naked sample holders. Two case studies were selected to demonstrate the functionality of the reactors: (i) annealing of hierarchical nanoporous gold up to 923 K under inert He environment and (ii) acquisition of a ptychographic projection series at ±35° of a hierarchically structured macroporous zeolite sample under ambient conditions. The reactors are shown to be a flexible and modular platform for in situ studies in catalysis and materials science which may be adapted for a range of sample and experiment types, opening new characterization pathways in correlative multimodal in situ analysis of functional materials at work. The cells will presently be made available for all interested users of beamline P06 at PETRA III. Full Article text
si Low-dose X-ray structure analysis of cytochrome c oxidase utilizing high-energy X-rays By scripts.iucr.org Published On :: 2019-06-14 To investigate the effect of high-energy X-rays on site-specific radiation-damage, low-dose diffraction data were collected from radiation-sensitive crystals of the metal enzyme cytochrome c oxidase. Data were collected at the Structural Biology I beamline (BL41XU) at SPring-8, using 30 keV X-rays and a highly sensitive pixel array detector equipped with a cadmium telluride sensor. The experimental setup of continuous sample translation using multiple crystals allowed the average diffraction weighted dose per data set to be reduced to 58 kGy, and the resulting data revealed a ligand structure featuring an identical bond length to that in the damage-free structure determined using an X-ray free-electron laser. However, precise analysis of the residual density around the ligand structure refined with the synchrotron data showed the possibility of a small level of specific damage, which might have resulted from the accumulated dose of 58 kGy per data set. Further investigation of the photon-energy dependence of specific damage, as assessed by variations in UV-vis absorption spectra, was conducted using an on-line spectrometer at various energies ranging from 10 to 30 keV. No evidence was found for specific radiation damage being energy dependent. Full Article text
si Fast identification of mineral inclusions in diamond at GSECARS using synchrotron X-ray microtomography, radiography and diffraction By scripts.iucr.org Published On :: 2019-07-19 Mineral inclusions in natural diamond are widely studied for the insight that they provide into the geochemistry and dynamics of the Earth's interior. A major challenge in achieving thorough yet high rates of analysis of mineral inclusions in diamond derives from the micrometre-scale of most inclusions, often requiring synchrotron radiation sources for diffraction. Centering microinclusions for diffraction with a highly focused synchrotron beam cannot be achieved optically because of the very high index of refraction of diamond. A fast, high-throughput method for identification of micromineral inclusions in diamond has been developed at the GeoSoilEnviro Center for Advanced Radiation Sources (GSECARS), Advanced Photon Source, Argonne National Laboratory, USA. Diamonds and their inclusions are imaged using synchrotron 3D computed X-ray microtomography on beamline 13-BM-D of GSECARS. The location of every inclusion is then pinpointed onto the coordinate system of the six-circle goniometer of the single-crystal diffractometer on beamline 13-BM-C. Because the bending magnet branch 13-BM is divided and delivered into 13-BM-C and 13-BM-D stations simultaneously, numerous diamonds can be examined during coordinated runs. The fast, high-throughput capability of the methodology is demonstrated by collecting 3D diffraction data on 53 diamond inclusions from Juína, Brazil, within a total of about 72 h of beam time. Full Article text
si Microfluidic electrochemical cell for in situ structural characterization of amorphous thin-film catalysts using high-energy X-ray scattering By scripts.iucr.org Published On :: 2019-08-09 Porous, high-surface-area electrode architectures are described that allow structural characterization of interfacial amorphous thin films with high spatial resolution under device-relevant functional electrochemical conditions using high-energy X-ray (>50 keV) scattering and pair distribution function (PDF) analysis. Porous electrodes were fabricated from glass-capillary array membranes coated with conformal transparent conductive oxide layers, consisting of either a 40 nm–50 nm crystalline indium tin oxide or a 100 nm–150 nm-thick amorphous indium zinc oxide deposited by atomic layer deposition. These porous electrodes solve the problem of insufficient interaction volumes for catalyst thin films in two-dimensional working electrode designs and provide sufficiently low scattering backgrounds to enable high-resolution signal collection from interfacial thin-film catalysts. For example, PDF measurements were readily obtained with 0.2 Å spatial resolution for amorphous cobalt oxide films with thicknesses down to 60 nm when deposited on a porous electrode with 40 µm-diameter pores. This level of resolution resolves the cobaltate domain size and structure, the presence of defect sites assigned to the domain edges, and the changes in fine structure upon redox state change that are relevant to quantitative structure–function modeling. The results suggest the opportunity to leverage the porous, electrode architectures for PDF analysis of nanometre-scale surface-supported molecular catalysts. In addition, a compact 3D-printed electrochemical cell in a three-electrode configuration is described which is designed to allow for simultaneous X-ray transmission and electrolyte flow through the porous working electrode. Full Article text
si Soft X-ray varied-line-spacing gratings fabricated by near-field holography using an electron beam lithography-written phase mask By scripts.iucr.org Published On :: 2019-08-16 A fabrication method comprising near-field holography (NFH) with an electron beam lithography (EBL)-written phase mask was developed to fabricate soft X-ray varied-line-spacing gratings (VLSGs). An EBL-written phase mask with an area of 52 mm × 30 mm and a central line density greater than 3000 lines mm−1 was used. The introduction of the EBL-written phase mask substantially simplified the NFH optics for pattern transfer. The characterization of the groove density distribution and diffraction efficiency of the fabricated VLSGs indicates that the EBL–NFH method is feasible and promising for achieving high-accuracy groove density distributions with corresponding image properties. Vertical stray light is suppressed in the soft X-ray spectral range. Full Article text
si Reducing sample consumption for serial crystallography using acoustic drop ejection By scripts.iucr.org Published On :: 2019-08-16 Efficient sample delivery is an essential aspect of serial crystallography at both synchrotrons and X-ray free-electron lasers. Rastering fixed target chips through the X-ray beam is an efficient method for serial delivery from the perspectives of both sample consumption and beam time usage. Here, an approach for loading fixed targets using acoustic drop ejection is presented that does not compromise crystal quality, can reduce sample consumption by more than an order of magnitude and allows serial diffraction to be collected from a larger proportion of the crystals in the slurry. Full Article text
si Transmission measurement at the Bernina branch of the Aramis Beamline of SwissFEL By scripts.iucr.org Published On :: 2019-10-23 The transmission of the optical components of the Bernina branch of the Aramis beamline at SwissFEL has been measured with an X-ray gas monitor from DESY and compared with a PSI gas detector upstream of the optical components. The transmission efficiencies of the Mo, Si and SiC mirror coatings of the Aramis beamline and the various other in-beam components were evaluated and compared with theoretical calculations, showing an agreement of 6% or better in all cases. The experiment has also shown the efficacy of the high-harmonic rejection mirrors at the Bernina branch of the Aramis beamline at SwissFEL, and characterized the transmission efficiency of the on-line spectrometer in the Aramis beamline. The theoretical transmission of the mirror coatings match the experimental data to within 7%. The accuracy of these measurements was checked against a radiative bolometer from a Japanese collaboration and found to agree to a level of 4% or better. Further comparisons with a diamond detector from a US-based inter-institute collaboration demonstrated a good agreement for the attenuator settings of the beamline. Full Article text
si Improved calibration of area detectors using multiple placements By scripts.iucr.org Published On :: 2019-10-23 Calibration of area detectors from powder diffraction standards is widely used at synchrotron beamlines. From a single diffraction image, it is not possible to determine both the sample-to-detector distance and the wavelength, but, with images taken from multiple positions along the beam direction and where the relative displacement is known, the sample-to-detector distance and wavelength can both be determined with good precision. An example calibration using the GSAS-II software package is presented. Full Article text
si X-ray fluorescence analysis of metal distributions in cryogenic biological samples using large-acceptance-angle SDD detection and continuous scanning at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III By scripts.iucr.org Published On :: 2020-01-01 A new Rococo 2 X-ray fluorescence detector was implemented into the cryogenic sample environment at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III, DESY, Hamburg, Germany. A four sensor-field cloverleaf design is optimized for the investigation of planar samples and operates in a backscattering geometry resulting in a large solid angle of up to 1.1 steradian. The detector, coupled with the Xspress 3 pulse processor, enables measurements at high count rates of up to 106 counts per second per sensor. The measured energy resolution of ∼129 eV (Mn Kα at 10000 counts s−1) is only minimally impaired at the highest count rates. The resulting high detection sensitivity allows for an accurate determination of trace element distributions such as in thin frozen hydrated biological specimens. First proof-of-principle measurements using continuous-movement 2D scans of frozen hydrated HeLa cells as a model system are reported to demonstrate the potential of the new detection system. Full Article text
si Full-field spectroscopic measurement of the X-ray beam from a multilayer monochromator using a hyperspectral X-ray camera By scripts.iucr.org Published On :: 2020-01-01 Multilayer monochromator devices are commonly used at (imaging) beamlines of synchrotron facilities to shape the X-ray beam to relatively small bandwidth and high intensity. However, stripe artefacts are often observed and can deteriorate the image quality. Although the intensity distribution of these artefacts has been described in the literature, their spectral distribution is currently unknown. To assess the spatio-spectral properties of the monochromated X-ray beam, the direct beam has been measured for the first time using a hyperspectral X-ray detector. The results show a large number of spectral features with different spatial distributions for a [Ru, B4C] strip monochromator, associated primarily with the higher-order harmonics of the undulator and monochromator. It is found that their relative contributions are sufficiently low to avoid an influence on the imaging data. The [V, B4C] strip suppresses these high-order harmonics even more than the former, yet at the cost of reduced efficiency. Full Article text
si White beam diagnostics using X-ray back-scattering from a CVD diamond vacuum window By scripts.iucr.org Published On :: 2020-01-01 Collecting back-scattered X-rays from vacuum windows using a pinhole X-ray camera provides an efficient and reliable method of measuring the beam shape and position of the white synchrotron beam. In this paper, measurements are presented that were conducted at ESRF beamline ID6 which uses an in-vacuum cryogenically cooled permanent-magnet undulator (CPMU18) and a traditional U32 undulator as its radiation sources, allowing tests to be performed at very high power density levels that were adjusted by changing the gap of the undulators. These measurements show that it is possible to record beam shape and beam position using a simple geometry without having to place any further items in the beam path. With this simple test setup it was possible to record the beam position with a root-mean-square noise figure of 150 nm. Full Article text
si A semi-analytical approach for the characterization of ordered 3D nanostructures using grazing-incidence X-ray fluorescence By scripts.iucr.org Published On :: 2020-02-11 Following the recent demonstration of grazing-incidence X-ray fluorescence (GIXRF)-based characterization of the 3D atomic distribution of different elements and dimensional parameters of periodic nanoscale structures, this work presents a new computational scheme for the simulation of the angular-dependent fluorescence intensities from such periodic 2D and 3D nanoscale structures. The computational scheme is based on the dynamical diffraction theory in many-beam approximation, which allows a semi-analytical solution to the Sherman equation to be derived in a linear-algebraic form. The computational scheme has been used to analyze recently published GIXRF data measured on 2D Si3N4 lamellar gratings, as well as on periodically structured 3D Cr nanopillars. Both the dimensional and structural parameters of these nanostructures have been reconstructed by fitting numerical simulations to the experimental GIXRF data. Obtained results show good agreement with nominal parameters used in the manufacturing of the structures, as well as with reconstructed parameters based on the previously published finite-element-method simulations, in the case of the Si3N4 grating. Full Article text
si X-ray fluorescence detection for serial macromolecular crystallography using a JUNGFRAU pixel detector By scripts.iucr.org Published On :: 2020-02-07 Detection of heavy elements, such as metals, in macromolecular crystallography (MX) samples by X-ray fluorescence is a function traditionally covered at synchrotron MX beamlines by silicon drift detectors, which cannot be used at X-ray free-electron lasers because of the very short duration of the X-ray pulses. Here it is shown that the hybrid pixel charge-integrating detector JUNGFRAU can fulfill this function when operating in a low-flux regime. The feasibility of precise position determination of micrometre-sized metal marks is also demonstrated, to be used as fiducials for offline prelocation in serial crystallography experiments, based on the specific fluorescence signal measured with JUNGFRAU, both at the synchrotron and at SwissFEL. Finally, the measurement of elemental absorption edges at a synchrotron beamline using JUNGFRAU is also demonstrated. Full Article text
si The HXD95: a modified Bassett-type hydrothermal diamond-anvil cell for in situ XRD experiments up to 5 GPa and 1300 K By scripts.iucr.org Published On :: 2020-01-29 A new diamond-anvil cell apparatus for in situ synchrotron X-ray diffraction measurements of liquids and glasses, at pressures from ambient to 5 GPa and temperatures from ambient to 1300 K, is reported. This portable setup enables in situ monitoring of the melting of complex compounds and the determination of the structure and properties of melts under moderately high pressure and high temperature conditions relevant to industrial processes and magmatic processes in the Earth's crust and shallow mantle. The device was constructed according to a modified Bassett-type hydrothermal diamond-anvil cell design with a large angular opening (θ = 95°). This paper reports the successful application of this device to record in situ synchrotron X-ray diffraction of liquid Ga and synthetic PbSiO3 glass to 1100 K and 3 GPa. Full Article text
si A lathe system for micrometre-sized cylindrical sample preparation at room and cryogenic temperatures By scripts.iucr.org Published On :: 2020-01-29 A simple two-spindle based lathe system for the preparation of cylindrical samples intended for X-ray tomography is presented. The setup can operate at room temperature as well as under cryogenic conditions, allowing the preparation of samples down to 20 and 50 µm in diameter, respectively, within minutes. Case studies are presented involving the preparation of a brittle biomineral brachiopod shell and cryogenically fixed soft brain tissue, and their examination by means of ptychographic X-ray computed tomography reveals the preparation method to be mainly free from causing artefacts. Since this lathe system easily yields near-cylindrical samples ideal for tomography, a usage for a wide variety of otherwise challenging specimens is anticipated, in addition to potential use as a time- and cost-saving tool prior to focused ion-beam milling. Fast sample preparation becomes especially important in relation to shorter measurement times expected in next-generation synchrotron sources. Full Article text
si A portable on-axis laser-heating system for near-90° X-ray spectroscopy: application to ferropericlase and iron silicide By scripts.iucr.org Published On :: 2020-02-13 A portable IR fiber laser-heating system, optimized for X-ray emission spectroscopy (XES) and nuclear inelastic scattering (NIS) spectroscopy with signal collection through the radial opening of diamond anvil cells near 90°with respect to the incident X-ray beam, is presented. The system offers double-sided on-axis heating by a single laser source and zero attenuation of incoming X-rays other than by the high-pressure environment. A description of the system, which has been tested for pressures above 100 GPa and temperatures up to 3000 K, is given. The XES spectra of laser-heated Mg0.67Fe0.33O demonstrate the potential to map the iron spin state in the pressure–temperature range of the Earth's lower mantle, and the NIS spectra of laser-heated FeSi give access to the sound velocity of this candidate of a phase inside the Earth's core. This portable system represents one of the few bridges across the gap between laser heating and high-resolution X-ray spectroscopies with signal collection near 90°. Full Article text
si ProQEXAFS: a highly optimized parallelized rapid processing software for QEXAFS data By scripts.iucr.org Published On :: 2020-02-07 The high temporal resolution in data acquisition, possible in the quick-scanning EXAFS (QEXAFS) mode of operation, provides new challenges in efficient data processing methods. Here a new approach is developed that combines an easy to use interactive graphical interface with highly optimized and fully parallelized Python-based routines for extracting, normalizing and interpolating oversampled time-resolved XAS spectra from a raw binary stream of data acquired during operando QEXAFS studies. The programs developed are freely available via a Github repository. Full Article text
si X-ray free-electron laser wavefront sensing using the fractional Talbot effect By scripts.iucr.org Published On :: 2020-02-12 Wavefront sensing at X-ray free-electron lasers is important for quantitatively understanding the fundamental properties of the laser, for aligning X-ray instruments and for conducting scientific experimental analysis. A fractional Talbot wavefront sensor has been developed. This wavefront sensor enables measurements over a wide range of energies, as is common on X-ray instruments, with simplified mechanical requirements and is compatible with the high average power pulses expected in upcoming X-ray free-electron laser upgrades. Single-shot measurements were performed at 500 eV, 1000 eV and 1500 eV at the Linac Coherent Light Source. These measurements were applied to study both mirror alignment and the effects of undulator tapering schemes on source properties. The beamline focal plane position was tracked to an uncertainty of 0.12 mm, and the source location for various undulator tapering schemes to an uncertainty of 1 m, demonstrating excellent sensitivity. These findings pave the way to use the fractional Talbot wavefront sensor as a routine, robust and sensitive tool at X-ray free-electron lasers as well as other high-brightness X-ray sources. Full Article text
si Limited angle tomography for transmission X-ray microscopy using deep learning By scripts.iucr.org Published On :: 2020-02-13 In transmission X-ray microscopy (TXM) systems, the rotation of a scanned sample might be restricted to a limited angular range to avoid collision with other system parts or high attenuation at certain tilting angles. Image reconstruction from such limited angle data suffers from artifacts because of missing data. In this work, deep learning is applied to limited angle reconstruction in TXMs for the first time. With the challenge to obtain sufficient real data for training, training a deep neural network from synthetic data is investigated. In particular, U-Net, the state-of-the-art neural network in biomedical imaging, is trained from synthetic ellipsoid data and multi-category data to reduce artifacts in filtered back-projection (FBP) reconstruction images. The proposed method is evaluated on synthetic data and real scanned chlorella data in 100° limited angle tomography. For synthetic test data, U-Net significantly reduces the root-mean-square error (RMSE) from 2.55 × 10−3 µm−1 in the FBP reconstruction to 1.21 × 10−3 µm−1 in the U-Net reconstruction and also improves the structural similarity (SSIM) index from 0.625 to 0.920. With penalized weighted least-square denoising of measured projections, the RMSE and SSIM are further improved to 1.16 × 10−3 µm−1 and 0.932, respectively. For real test data, the proposed method remarkably improves the 3D visualization of the subcellular structures in the chlorella cell, which indicates its important value for nanoscale imaging in biology, nanoscience and materials science. Full Article text
si X-ray absorption linear dichroism at the Ti K-edge of rutile (001) TiO2 single crystal By scripts.iucr.org Published On :: 2020-02-14 X-ray absorption linear dichroism of rutile TiO2 at the Ti K-edge provides information about the electronic states involved in the pre-edge transitions. Here, linear dichroism with high energy resolution is analyzed in combination with ab initio finite difference method calculations and spherical tensor analysis. It provides an assignment of the three pre-edge peaks beyond the octahedral crystal field splitting approximation and estimates the spatial extension of the corresponding final states. It is then discussed for the first time the X-ray absorption (XAS) of pentacoordinated titanium atoms due to oxygen vacancies and it is found that, similarly to anatase TiO2, rutile is expected to exhibit a transition on the low-energy side of peak A3. Its apparent absence in the experiment is related to the degree of p–d orbital mixing which is small in rutile due to its centrosymmetric point group. A recent XAS linear dichroism study on anatase TiO2 single crystals has shown that peak A2 has an intrinsic origin and is due to a quadrupolar transition to the 3d energy levels. In rutile, due to its centrosymmetric point group, the corresponding peak A2 has a small dipole moment explaining the weak transition. The results are confronted with recent picosecond X-ray absorption spectroscopy on rutile TiO2 nanoparticles. Full Article text
si Foreword to the special virtual issue dedicated to the proceedings of the PhotonDiag2018 workshop on FEL Photon Diagnostics, Instrumentation, and Beamlines Design By scripts.iucr.org Published On :: 2020-03-01 Full Article text
si Contributions of charge-density research to medicinal chemistry By journals.iucr.org Published On :: Contributions of experimental and selected theoretical charge-density research to medicinal chemistry are reviewed; combining experimental methods from high-resolution small-molecule and macromolecular crystallography with theory proves to be fruitful. Full Article text
si Beyond simple small-angle X-ray scattering: developments in online complementary techniques and sample environments By journals.iucr.org Published On :: Possibilities in auxiliary technique combinations with small- and wide-angle X ray scattering are described, as well as more complicated sample environments used in X-ray and neutron scattering. Full Article text
si Correlated changes in structure and viscosity during gelatinization and gelation of tapioca starch granules By journals.iucr.org Published On :: Melting of the semicrystalline structure of native tapioca starch granules is correlated to solution viscosity for elucidating gelatinization and gelation processes. Full Article text
si Location of Cu2+ in CHA zeolite investigated by X-ray diffraction using the Rietveld/maximum entropy method By journals.iucr.org Published On :: Rietveld/MEM analysis applied to synchrotron powder X-ray diffraction data of dehydrated CHA zeolites with catalytically active Cu2+ reveals Cu2+ in both the six- and eight-membered rings in the CHA framework, providing the first complete structural model that accounts for all Cu2+. Density functional theory calculations are used to corroborate the experimental structure and to discuss the Cu2+ coordination in terms of the Al distribution in the framework. Full Article text
si The indexing ambiguity in serial femtosecond crystallography (SFX) resolved using an expectation maximization algorithm By journals.iucr.org Published On :: An expectation maximization algorithm is implemented to resolve the indexing ambiguity which arises when merging data from many crystals in protein crystallography, especially in cases where partial reflections are recorded in serial femtosecond crystallography (SFX) at XFELs. Full Article text
si Investigating increasingly complex macromolecular systems with small-angle X-ray scattering By journals.iucr.org Published On :: A review of recent and ongoing development and results within the field of biological solution small-angle X-ray scattering (BioSAXS), with a focus on the increasing complexity of biological samples, data collection and data evaluation strategies. Full Article text