Separation Threshold Research Articles

A Radar Linear Feature Fitting Algorithm Combining Adaptive Clustering and Corner Detection Operator

The precise environmental parameters derived from laser radar scan data can significantly accelerate the process of real‐time localization and map‐matching technique. One of the research directions is autonomous navigation algorithm based on LiDAR slam. LiDAR has the advantage of having a wide range of accuracy and distance. However, due to the limited amount of LiDAR data available and the influence of sensor noise, it is easy to run into issues such as low accuracy of robot map construction or large positioning errors. At the moment, most of feature extraction algorithms employ an iterative calculation method with high computational complexity and a large amount of computation. Furthermore, due to the dependence of the fixed separation threshold, the algorithms for extracting the linear features of laser radar data are typically undersegment and oversegment. As a result, this paper proposes a radar linear feature fitting algorithm that combines adaptive clustering and corner detection operators. First, bilateral filtering is used to reduce noise and remove invalid data points. Second, the LiDAR data points are classified using adaptive threshold clustering of distance and density. The corner detection operator is applied to the classified data points to determine all possible corners then. Finally, the least square method is used to linearly fit each class and the identified corners within each class. The simulation and experimental results demonstrate that this method avoids the influence of noise points and a fixed segmentation threshold on corner point extraction effectively. The standard variance of length is 9.41 × 10−5m2 for corner feature extraction and localization in the dataset Cartographer ROS 2D Laser SLAM at Deutsches Museum. When compared to PDBS (point distance based methods) and IEPF (iterative end point fit), only about half the time is used, the accuracy of partition processing is improved by 11.6%, and the accuracy of corner detection is improved by 20.1%. The proposed algorithm can extract the corner features of data frames and linear positioning through experimental verification accurately. The features of the laser scan data that fit are more realistic. It has higher calculation efficiency and position accuracy. It ensures real‐time mobile robot map construction and is appropriate for autonomous robot map algorithms developed in embedded systems.

DD-ComDim: A data-driven multiblock approach for one-class classifiers

An attractive alternative to solve authentication challenges is the combination of fingerprint analytical techniques with multivariate methods of one-class classifiers (OCC). In this proof of concept, we propose a novel multiblock method for OCC that emerged from the association of the common dimension (ComDim) analysis with the dual data-driven, which allows to calculate errors of misclassification based on the orthogonal and score distances with a subsequent determination of their cut-off levels. The applicability of data-driven – common dimension (DD-ComDim) analysis was verified for the authentication of diesel S10 (10 ppm of sulfur) against S500 (500 ppm of sulfur) using two low-field 1H NMR datasets: medium-resolution (MR-NMR) and time-domain NMR relaxometry (TD-NMR). The performance of the DD-ComDim (mid-level data fusion) was compared with data-driven – soft independent modeling of class analogy (DD-SIMCA) for each data set separately and concatenated (low-level data fusion). The results suggest that this novel method can improve the quality and efficiency of the model in authentication when compared to a traditional method. In addition, it demonstrated that the threshold of separation between target and non-target classes was more evident with the mid-level data fusion approach. Other applications are currently underway, intending to verify the method's applicability with other matrices and analytical techniques to confirm the reliability of the DD-ComDim.

Mechanism of Phase Separation in Aqueous Two-Phase Systems.

Liquid-liquid phase separation underlies the formation of membrane-less organelles inside living cells. The mechanism of this process can be examined using simple aqueous mixtures of two or more solutes, which are able to phase separate at specific concentration thresholds. This work presents the first experimental evidence that mesoscopic changes precede visually detected macroscopic phase separation in aqueous mixtures of two polymers and a single polymer and salt. Dynamic light scattering (DLS) analysis indicates the formation of mesoscopic polymer agglomerates in these systems. These agglomerates increase in size with increasing polymer concentrations prior to visual phase separation. Such mesoscopic changes are paralleled by changes in water structure as evidenced by Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopic analysis of OH-stretch bands. Through OH-stretch band analysis, we obtain quantitative estimates of the relative fractions of four subpopulations of water structures coexisting in aqueous solutions. These estimates indicate that abrupt changes in hydrogen bond arrangement take place at concentrations below the threshold of macroscopic phase separation. We used these experimental observations to develop a model of phase separation in aqueous media.

The need to distinguish intervention thresholds and diagnostic thresholds in the management of osteoporosis.

This position paper of the International Osteoporosis Foundation (IOF) and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) addresses the rationale for separate diagnostic and intervention thresholds in osteoporosis. We conclude that the current BMD-based diagnostic criteria for osteoporosis be retained whilst clarity is brought to bear on the distinction between diagnostic and intervention thresholds.

Post-systolic shortening index by echocardiography evaluation of dyssynchrony in the non-dilated and hypertrophied left ventricle

Abstract Background Post-systolic shortening index (PSI) is defined as myocardial shortening that occurs after aortic valve closure, and is an emerging measure of regional LV contractile dysfunction. PSI measurement variability amongst software vendor and its relationship with mechanical dyssynchrony and mechanical dispersion index (MDI) remains unknown. We evaluated PSI by speckle-tracking echocardiography from several vendors in patients with increased left ventricular wall thickness, and associations with MDI. Methods This is a prospective cross-sectional study of 70 patients (36 hypertrophic cardiomyopathy [HCM], 18 cardiac amyloidosis and 16 healthy controls) undergoing clinically indicated echocardiography. PSI was measured using QLAB/aCMQ (Philips), QLAB/LV auto-trace (Philips), EchoPAC (GE), Velocity Vector Imaging (Siemens), and EchoInsight (EPSILON) software packages, and calculated as 100% × (post systolic strain − end-systole strain)/post systolic strain. Results There was a significant difference in mean PSI among controls 2.1±0.6%, HCM 6.1±2.6% and cardiac amyloidosis 6.8±2.7% (p<0.001). Variations between software vendors were significant in patients with pathologic increases in LV wall thickness (for HCM p=0.03, for amyloidosis p=0.008), but not in controls (p=0.11), as seen in Figure 1. Furthermore, there were moderate correlations between PSI and both MDI (r=0.77) and left ventricular global longitudinal strain (r=0.69), as seen in Figure 2. Conclusion PSI was greater in HCM and cardiac amyloidosis patients than controls, and a valuable tool for dyssynchrony evaluation, with moderate correlations to MDI and strain. However, there were significant variations in PSI measurements by software vendor especially in patients with pathological increase in LV wall thickness, suggesting that separate vendor-specific thresholds for abnormal PSI are required. Funding Acknowledgement Type of funding sources: None.

Prompt Emission of γ-Ray Bursts in the High-density Environment of Active Galactic Nucleus Accretion Disks

Long and short γ-ray bursts (GRBs) are traditionally associated with galactic environments, where circumburst densities are small or moderate (few to hundreds of protons per cubic centimeter). However, both are also expected to occur in the disks of active galactic nuclei, where the ambient medium density can be much larger. In this work we study, via semianalytical methods, the propagation of the GRB outflow, its interaction with the external material, and the ensuing prompt radiation. In particular, we focus on the case in which the external shock develops early in the evolution at a radius that is smaller than the internal shock one. We find that bursts in such high-density environments are likely characterized by a single, long emission episode that is due to the superposition of individual pulses, with a characteristic hard-to-soft evolution irrespective of the light-curve luminosity. While multipulse light curves are not impossible, they would require the central engine to go dormant for a long time before reigniting. In addition, short GRB engines would produce bursts with prompt duration that would exceed the canonical 2 s separation threshold and likely be incorrectly classified as long events, even though they would not be accompanied by a simultaneous supernova. Finally, these events have a large dynamical efficiency, which would produce a bright prompt emission followed by a somewhat dim afterglow.

The Study of Energy Management Scheme of Hybrid Energy Storage System for Responding High Demand with Long Period

Most large and controlled buildings require high power demand with long period. However, there are restrictions on building facilities and image when it comes to reducing electricity consumption. Another option is to install a roof-top solar power system, though due to the small installation area, it will only partially reduce energy use. Hybrid energy storage systems in combination with AGM batteries and LFP batteries are now offered as a lower cost energy management solution. AGM batteries are constrained in their ability to produce current, hence a larger current supply will reduce the battery's useable capacity. Therefore, in order to respond to high demand with long period, this research proposed a separate multi-level threshold control of the battery packs, and used the control factor in the form of current ratio to divide the load response for each battery type: On-Peak in AGM: LFP at 0.7:0.3, Off-Peak in AGM : LFP at 0.5 : 0.5. And when one battery was not ready for use, the other battery would be run at full capacity. The results showed that the AGM battery had a peak discharge current of 12.7A, or approximately 0.5C when coupled with an LFP battery, and when processing power storage system capacity, a loss of 8.99 kWh occurred. or 6.8% of the overall capacity.

Soil Reflectance Composites—Improved Thresholding and Performance Evaluation

Reflectance composites that capture bare soil pixels from multispectral image data are increasingly being analysed to model soil constituents such as soil organic carbon. These temporal composites are used instead of single-date multispectral images to account for the frequent vegetation cover of soils and, thus, to get broader spatial coverage of bare soil pixels. Most soil compositing techniques require thresholds derived from spectral indices such as the Normalised Difference Vegetation Index (NDVI) and the Normalised Burn Ratio 2 (NBR2) to separate bare soils from all other land cover types. However, the threshold derivation is handled based on expert knowledge of a specific area, statistical percentile definitions or in situ data. For operational processors, such site-specific and partly manual strategies are not applicable. There is a need for a more generic solution to derive thresholds for large-scale processing without manual intervention. This study presents a novel HIstogram SEparation Threshold (HISET) methodology deriving spectral index thresholds and testing them for a Sentinel-2 temporal data stack. The technique is spectral index-independent, data-driven and can be evaluated based on a quality score. We tested HISET for building six soil reflectance composites (SRC) using NDVI, NBR2 and a new index combining the NDVI and a short-wave infrared (SWIR) band (PV+IR2). A comprehensive analysis of the spectral and spatial performance and accuracy of the resulting SRCs proves the flexibility and validity of HISET. Disturbance effects such as spectral confusion of bare soils with non-photosynthetic-active vegetation (NPV) could be reduced by choosing grassland and crops as input LC for HISET. The NBR2-based SRC spectra showed the highest similarity with LUCAS spectra, the broadest spatial coverage of bare soil pixels and the least number of valid observations per pixel. The spatial coverage of bare soil pixels is validated against the database of the Integrated Administration and Control System (IACS) of the European Commission. Validation results show that PV+IR2-based SRCs outperform the other two indices, especially in spectrally mixed areas of bare soil, photosynthetic-active vegetation and NPV. The NDVI-based SRCs showed the lowest confidence values (95%) in all bands. In the future, HISET shall be tested in other areas with different environmental conditions and LC characteristics to evaluate if the findings of this study are also valid.

Variational crack phase-field model for ductile fracture with elastic and plastic damage variables

Based on the study on characteristic features of existing crack phase-field (PF) models for ductile fracture, we propose a new model endowed with elastic and plastic damage variables. In the review part, the emphasis is placed on the plastic driving force and degrading fracture toughness that enable PF models to represent damage evolution in elastoplastic materials. Attention is also paid to the damage evolution tendency in terms of the definition of the yield function. Based on the reviewed features, we originally formulate the proposed model, which separately accommodates two damage variables for elasticity and plasticity. Its constitutive work density consists of elastic, plastic hardening, and damage hardening components. Evolution laws for plasticity and damage are derived by using separate threshold (yield) functions while having similar formats so that those for damage hold variational and thermodynamic consistencies. Also, the proposed model is equipped with thresholds and coefficients to control the amount of damage driving force. Several numerical examples are presented to demonstrate the characteristic features of the proposed model and the ability to mimic the typical fracture behavior of elastoplastic materials.

Machine Perfusion as "Comfort Zone": What Are Key Challenges of Liver Viability Assessment Today?

Machine Perfusion as "Comfort Zone": What Are Key Challenges of Liver Viability Assessment Today?

Post-systolic shortening index by echocardiography evaluation of dyssynchrony in the non-dilated and hypertrophied left ventricle.

Post-systolic shortening index (PSI) is defined as myocardial shortening that occurs after aortic valve closure, and is an emerging measure of regional LV contractile dysfunction. PSI measurement variability amongst software vendor and its relationship with mechanical dyssynchrony and mechanical dispersion index (MDI) remains unknown. We evaluated PSI by speckle-tracking echocardiography from several vendors in patients with increased left ventricular wall thickness, and associations with MDI. This is a prospective cross-sectional study of 70 patients (36 hypertrophic cardiomyopathy [HCM], 18 cardiac amyloidosis and 16 healthy controls) undergoing clinically indicated echocardiography. PSI was measured using QLAB/aCMQ (Philips), QLAB/LV auto-trace (Philips), EchoPAC (GE), Velocity Vector Imaging (Siemens), and EchoInsight (EPSILON) software packages, and calculated as 100%×(post systolic strain-end-systole strain)/post systolic strain. There was a significant difference in mean PSI among controls 2.1±0.6%, HCM 6.1±2.6% and cardiac amyloidosis 6.8±2.7% (p <0.001). Variations between software vendors were significant in patients with pathologic increases in LV wall thickness (for HCM p = 0.03, for amyloidosis p = 0.008), but not in controls (p = 0.11). Furthermore, there were moderate correlations between PSI and both MDI (r = 0.77) and left ventricular global longitudinal strain (r = 0.69). PSI was greater in HCM and cardiac amyloidosis patients than controls, and a valuable tool for dyssynchrony evaluation, with moderate correlations to MDI and strain. However, there were significant variations in PSI measurements by software vendor especially in patients with pathological increase in LV wall thickness, suggesting that separate vendor-specific thresholds for abnormal PSI are required.

Analysis of factors affecting occupant injury severity in rear-end crashes by different struck vehicle groups: A random thresholds random parameters hierarchical ordered probit model

This study aims to explore the variability of risk factors affecting injury severity in rear-end crashes when different struck vehicle groups are involved. Two types of rear-end crash data, vehicle-strike-car data, vehicle-strike-truck data, are extracted from the Fatality Analysis Reporting System (FARS). Two likelihood ratio (LR) tests are firstly performed to validate the struck vehicle group variations, and then two separate random thresholds random parameters hierarchical ordered probit (RRHOP) models (Model 1 and Model 2) are established to capture unobserved heterogeneity. The results of LR test show significant differences in the effects of factors included in each model. Moreover, the model results suggest that SUVs, vans, and large trucks as striking vehicles are significant related to injury severity in both models with different effects. Factors such as speeding related, pickup, model year (struck vehicle), disabled damage, adverse weather, speed limit (≥60 mile/h), and young driver (struck vehicle) are found to be statistically significant in only model 1. These results provide a better understanding of differences in contributing factors of rear-end crashes, which help to propose effective countermeasures to mitigate its injury severity.

Beyond-mean-field study of Ar based on the Skyrme-Hartree-Fock model * *Supported by the National NaturalScience Foundation of China (11905165, 11775081,12175071, 11547044), the 111 Project (B17035), andthe Fundamental Research Funds for the Central Universities(JB160510, XJS18020).

We present the hypernuclear states of Ar obtained using the Skyrme-Hartree-Fock (SHF) model and a beyond-mean-field approach, including angular momentum projection (AMP) and the generator coordinate method (GCM). A comprehensive energy spectrum is given, which includes normally deformed (ND) and super deformed (SD) hypernuclear states with positive or negative parities. Energy levels corresponding to the configurations in which a hyperon occupies the s-, p-, or sd-shell orbitals are discussed. For the s-shell , we pay special attention to the ND and SD states corresponding to the configurations Ar s and Ar s , where Ar and Ar denote the ND and SD nuclear cores, respectively. The disagreements between different models over the separation energy of the SD state in previous studies are revisited. For the p-shell , four rotational bands are predicted, and the impurity effects are shown. Furthermore, two energy levels corresponding to the configurations Ar [101] and Ar [101] are obtained below the separation threshold of Ar+ within 0.5 MeV. For the sd-shell , three bound states are found near the separation threshold, and the mechanism behind these states are discussed.

&amp;lt;italic&amp;gt;Ab initio&amp;lt;/italic&amp;gt; Gamow shell model with chiral three-nucleon force for&amp;lt;sup&amp;gt;14&amp;lt;/sup&amp;gt;O isotones

<p indent="0mm">Proton-rich nuclei exhibit many novel phenomena, such as proton emission, proton halo, and Thomas-Ehrman shift. On one hand, due to the Coulomb force, outer protons have a lower nuclear separation threshold and are strongly coupled to the continuum. Such weakly bound nuclei are called the open quantum system. On the other hand, the Coulomb barrier restricts the spatial spread of the weakly-bound outer protons, resulting in that unbound resonance nuclei beyond the proton drip line may have certain lifetimes, e.g., a millisecond lifetime. The interplay of the continuum coupling and Coulomb forces produces a complex pattern in nuclei near the proton-rich drip line, which contains rich and unique structures and dynamic information. These properties lead to new insights into nuclear forces, symmetry breaking between mirror nuclei and many-body correlations. Recent experiment observed the ground state of ¹⁸Mg via its decay into 4p<italic>+</italic>¹⁴O. The decay of the ground state of this nucleus is consistent with two sequential steps of 2p decay passing through the ground state of ¹⁶Ne. And another excited state at <sc>1.84 MeV</sc> was also observed, which may be the first 2⁺ excited state. The excitation energy of this 2⁺ state is significantly higher than that in ¹⁸C, which shows a typical Thomas-Ehrman shift. In addition, this 2⁺ excitation energy of ¹⁸Mg exceeds that of ²⁰Mg. It is meaningful to study these novel phenomena through <italic>ab initio</italic> calculations. However, continuum coupling is important in these proton-rich nuclei, so the continuum degrees of freedom should be treated properly. Using the Berggren basis, the Gamow shell model provides a good description of the interplay between bound state, resonance, and continuum in a self-consistent many-body framework. In the present paper, we employ two- and three-nucleon forces from chiral effective theory, perform the Gamow shell model calculations of ^15–18C and ¹⁵F–¹⁸Mg with continuum coupling included. The Gamow Hartree-Fock method with three-body force included was used to generate the Berggren basis, it can give a good description of the bound, resonant, and scattering states. The Hamiltonian is then normal ordered with respect to the Gamow Hartree-Fock reference state, and the normal ordered two-body approximation is adopted. We use the many-body perturbation theory to construct the effective Hamiltonian for the psd model space with s_1/2 and d_5/2 partial waves treated in Berggren basis. We calculate the <inline-formula content-type="pic" id="INLINE22"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true" other="0"><mml:mi other="0">S</mml:mi><mml:mo other="1">^</mml:mo></mml:mover></mml:math></inline-formula>-box up to the third order and <inline-formula content-type="pic" id="INLINE23"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true" other="0"><mml:mi other="0">Q</mml:mi><mml:mo other="1">^</mml:mo></mml:mover></mml:math></inline-formula>-box up to the second order. We use the Jacobi-Davidson method to diagonalize the complex-symmetric model-space Hamiltonian, and allow at most two valence particles in the continuum. The energies of the ground and first 2⁺ excited states are calculated for ^15–18C and ¹⁵F–¹⁸Mg. The calculated energies agree well with experimental data or evaluations. By calculating occupation probabilities and effective single-particle energies of the <inline-formula id="INLINE24"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mtext>π</mml:mtext><mml:mn>1</mml:mn><mml:msub other="0"><mml:mtext other="0">s</mml:mtext><mml:mrow other="1"><mml:mn other="1">1</mml:mn><mml:mo other="1">/</mml:mo><mml:mn other="1">2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> and <inline-formula id="INLINE25"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mtext>π</mml:mtext><mml:mn>0</mml:mn><mml:msub other="0"><mml:mtext other="0">d</mml:mtext><mml:mrow other="1"><mml:mn other="1">5</mml:mn><mml:mo other="1">/</mml:mo><mml:mn other="1">2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> orbitals, we analyze the continuum-coupling effect in the ground state of ¹⁸Mg. The calculation of the mirror energy difference between the 2⁺ states of ¹⁸C and ¹⁸Mg is improved with continuum coupling included. We have systematically calculated the first 2⁺ states in <italic>Z</italic>=12 isotopes, supporting the experimental observation that the 2⁺ excitation energy in ¹⁸Mg is slightly higher than that in ²⁰Mg. There have been no experimental data for ²⁰Si and ²²Si. We predict that the 2⁺ excitation energy in ²⁰Si is lower than that in ²²Si with the real-energy shell-model calculation.

Dual AGN in the Horizon-AGN simulation and their link to galaxy and massive black hole mergers, with an excursus on multiple AGN

ABSTRACT The occurrence of dual active galactic nuclei (AGN) on scales of a few tens of kpc can be used to study merger-induced accretion on massive black holes (MBHs) and to derive clues on MBH mergers, using dual AGN as a parent population of precursors. We investigate the properties of dual AGN in the cosmological simulation Horizon-AGN. We create catalogs of dual AGN selected with distance and luminosity criteria, plus sub-catalogs where further mass cuts are applied. We divide the sample into dual AGN hosted in different galaxies, on the way to a merger, and into those hosted in one galaxy, after the galaxy merger has happened. We find that the relation between MBH and galaxy mass is similar to that of general AGN population and we compare the properties of dual AGN also with a control sample, discussing differences and similarities in masses and Eddington ratios. The typical mass ratio of galaxy mergers associated to dual AGN is 0.2, with mass loss in the smaller galaxy decreasing the mass ratio as the merger progresses. Between 30 and 80 per cent of dual AGN with separations between 4 and 30 kpc can be matched to an ensuing MBH merger. The dual AGN fraction increases with redshift and with separation threshold, although above 50 kpc the increase of multiple AGN limits that of duals. Multiple AGN are generally associated with massive haloes, and mass loss of satellites shapes the galaxy–halo relation.

Effect of coronal fracture angle on the stability of screw fixation in medial malleolar fractures: A finite element analysis.

Malleolar screw fixation is the most widely used treatment method for medial malleolar (MM) fractures. Here, although buttress plate fixation is advocated for vertical MM fractures, the angular discrimination between oblique and vertical MM fractures is still not fully understood. The purpose of this study is to test the adequacy of screw fixation in MM fractures with different angles and determination of a 'critical fracture angle' to guide surgeons in the decision-making for screw fixation for MM fractures by utilizing an advanced engineering simulation approach. In addition to loading of the healthy tibia structure, various cases of the MM fracture double screw fixation (14 simulation scenarios in total with fracture angles between 30° and 90°, in 5° increments) were considered in this research and their static loading conditions just after fixation operation were simulated through nonlinear (geometric and contact nonlinearity) finite element analysis (FEA). Patient-specific computed tomography scan data, parametric three-dimensional solid modelling and finite element method (FEM) based engineering codes were employed in order to simulate the fixation scenarios. Visual and numerical outputs for the deformation and stress distributions, separation and sliding behaviours of the MM fracture fragments of various screw fixations were clearly exhibited through FEA results. Minimum and maximum separation distances (gap) of 3.75 and 150.34 µm between fracture fragments at fracture angles of 30° and 90° were calculated respectively against minimum and maximum sliding distances of 25.87 and 41.37 µm between fracture fragments at fracture angles of 90° and 35°, respectively. The FEA results revealed that while the separation distance was increasing, the sliding distance was decreasing and there were no distinct differences in sliding distances in the scenarios from fracture angles of 30°-90°. The limitations and errors in a FEA study are inevitable, however, it was interpreted that the FEA scenarios were setup in this study by utilizing acceptable assumptions providing logical outputs under pre-defined boundary conditions. Finally, the fracture healing threshold for separation and/or sliding distance between fracture fragments was assigned as 100 µm by referring to previous literature and it was concluded that the screws fixed perpendicular to the fracture in a MM fracture with more than 70° angle with the tibial plafond results in a significant articular separation (>100 µm) during single-leg stand. Below this critical angle of 70°, two screws provide sufficient fixation.

Prediction of iron ore mineral liberation behavior using the Andrews–Mika diagram and beta distribution

A combined grinding and liberation model was studied to predict the liberation characteristics of iron ore comminuted by a ball mill. Comminution characteristics were obtained using the one-size-fraction method; then, the iron ore samples were crushed and separated into several narrow-size fractions by screening. The size fractions were further divided into three classes by magnetic separation, namely concentrate, middling, and tailings. Subsequently, various size classes were subjected to ball milling, and the results were analyzed in the kinetic grinding model. The mineralogical textures of the ground products were analyzed using mineral liberation analysis. The beta distribution and Andrews–Mika diagram characterized the distribution of the iron content within the size fractions. The breakage characteristics of the iron ore samples varied slightly with the iron content. However, the liberation characteristics were well-described by adjusting the four parameters of the beta distribution. The variation in grinding kinetics with composition and liberation model parameters was used in the combined liberation–comminution model to predict the evolution of the size–composition matrix as grinding proceeded. The predicted results align with the experimental results. The developed model can construct a yield–recovery graph and calculate the liberation efficiency to determine the size reduction threshold for efficient separation.

Experimental and numerical studies on micro-bumps without melting of gold films with different thicknesses induced by ultrafast laser

The micro-bumps of metal films induced by ultrafast laser have potential applications in various fields, suchas biotechnology and energy, etc. The mechanism of micro-bump deformation of the gold film irradiated by single ultrafast laser pulse is controversial. In this study, the experimental research of single ultrafast laser pulse irradiating gold films with different thicknesses from 20 nm to 200 nm is carried out, with the laser fluence varying from 1 to 50 J/cm 2. The micro-bumps without melting are observed by the Scanning Electron Microscope (SEM) and different separation thresholds can be obtained. The separation threshold of gold films ranges from 5.1 to 43.5 J/cm 2 and it increases with the thickness of gold film increasing. The heights of micro-bumps are measured by Atomic Force Microscope (AFM). One-dimension (1D) Molecular dynamic (MD) simulations are carried out to analyze the temperature and stress evolutions. Large-scale two-dimension (2D) MD simulations are furthermore performed to obtain the micro-bump structure. MD simulations showing a good agreement with experiments, and the essential mechanism responsible for micro-bump without melting is clearly analyzed. It is also analyzed that the heights of micro-bumps are related to the laser fluences and radii of spot.

Probabilistic rainfall threshold of landslides in Data-Scarce mountainous Areas: A case study of the Bailong River Basin, China

The damage caused by rainfall-induced landslides has increased globally. The development of urbanisation has led to the expansion of residential areas in mountainous areas, and human activities have accelerated slope instability. However, the limited data records in mountainous zones have resulted in low-precision landslide rainfall thresholds. Establishing a landslide early warning model in areas with scarce data is an unresolved problem. This study uses the Bailong River Basin in western China as an example. By downscaling Tropical Rainfall Measuring Mission (TRMM) data to a daily resolution of 1 km and conditionally merging it with ground station rainfall, we obtain high-precision rainfall data to establish rainfall threshold curves based on Bayes' theorem and the frequency method. Subsequently, a landslide susceptibility map based on deep learning was integrated to construct a regional landslide early warning model. The results are as follows: First, compared with downscaling rainfall and rain gauge interpolation data, the daily rainfall data with a resolution of 1 km that combines the two has better overall performance and higher accuracy. Second, we generated the event-rainfall-and-duration threshold curves of 5%, 20%, and 50% probability by combining the frequency method and Bayesian theorem, and show that with a probability of landslide occurrence of 50%, while the intercept of Bayes' theorem is greater than that of the frequency method, the overall trend is consistent. Finally, by using a typical mass rainfall event to test the performance, the results show that the early warning capability of the model integrated with the rainfall threshold and landslide susceptibility map is more accurate than that of using a separate rainfall threshold. The outcomes of this research are expected to provide efficient support for early warning and risk management of geological disasters in mountainous areas with scarce data.

Human cytomegalovirus forms phase-separated compartments at viral genomes to facilitate viral replication.

SummaryHuman cytomegalovirus (HCMV) replicates its DNA genome in specialized replication compartments (RCs) in the host cell nucleus. These membrane-less organelles originate as spherical structures and grow in size over time. However, the mechanism of RC biogenesis has remained understudied. Using live-cell imaging and photo-oligomerization, we show that a central component of RCs, the UL112-113 proteins, undergo liquid-liquid phase separation (LLPS) to form RCs in the nucleus. We show that the self-interacting domain and large intrinsically disordered regions of UL112-113 are required for LLPS. Importantly, viral DNA induces local clustering of these proteins and lowers the threshold for phase separation. The formation of phase-separated compartments around viral genomes is necessary to recruit the viral DNA polymerase for viral genome replication. Thus, HCMV uses its UL112-113 proteins to generate RCs around viral genomes by LLPS to ensure the formation of a pro-replicative environment.