Severe Distortion Research Articles

Analysis of the Tomato Aspermy Virus Complete Genomes Suggests Reassortment in Russian Isolates from Chrysanthemum

Tomato aspermy virus (TAV, genus Cucumovirus from the family Bromoviridae) is one of the most common and harmful chrysanthemum viruses, causing severe flower distortion, size reduction and color breaking. Metatranscriptome sequencing of chrysanthemum plants of the Ribonette and Golden Standard cultivars from the collection of the Nikita Botanical Garden (Yalta, Republic of Crimea) generated TAV-related reads. The complete genomes of two Russian isolates of the virus were assembled from the reads obtained. This is the first report of full-length TAV genomes from Russia. Typically of cucumoviruses, the segmented TAV genome is represented by three single-stranded positive-sense linear RNA molecules with a length of 3412 (RNA1), 3097 (RNA2) and 2219 (RNA3) nucleotides. Five open reading frames (ORF) have been identified that encode replicase (ORF1), RNA-dependent RNA polymerase (ORF2a), silencing suppressor protein (OFR2b), movement protein (OFR3a) and the virus coat protein (ORF3b). The identity of the TAV genomes from the two chrysanthemum cultivars was 99.8% for all three viral RNAs, and with other TAV isolates from Genbank – 97.5–99.7 (RNA1), 93.8–99.8 (RNA2), and 89.3–99.3% (RNA3). Phylogenetic analysis showed that RNA1 and RNA3 of the Russian isolates were assigned to heterogeneous groups of TAV isolates found on various plant species in different regions of the world. At the same time, RNA2 clearly clustered with tomato isolates SKO20ST2 from Slovenia and PV-0220 from Bulgaria and, to a lesser extent, with the Iranian isolate Ker.Mah.P from petunia and the Chinese isolate Henan from chrysanthemum. The incongruence of phylogenetic trees reconstructed from different segments of the viral genome suggests pseudo-recombination (reassortment) in the Russian TAV isolates.

Disorder on Mixed Cation Halide Perovskite for Photovoltaic Applications.

With reduced toxicity and tunable optoelectronic properties, mixed cation halide perovskites (MCHPs) featuring partially substituted Pb with Sn and Ge have emerged as promising candidates for photovoltaic applications. However, the introduction of the disorder through large-scale preparation and alloying strategies leads to a significant challenge in comprehending the disorder's microscopic-level impact. Here, we found that, in addition to compositional variation, a synergy of disorder and cation radii ratio significantly affects optoelectronic properties. For Pb-Ge/Ge-Sn MCHPs, severe octahedral distortion with increasing degree of disorder adjusted their bandgaps in a wide range, giving rise to large effective masses, exciton binding energies, and weak visible absorption coefficients. The synergy of disorder and distortion transforms the Wannier excitons into localized characteristics, whereas the optoelectronic properties of Pb-Sn MCHPs are modulated by the disorder. Our work highlights the role of disorder in the tunability of optoelectronic properties, providing a novel strategy for designing photovoltaic materials.

Effect of Ti on microstructure and mechanical properties of Al0.8Nb0.5TixV2Zr0.5 refractory complex concentrated alloys

In this study, lightweight Al0.8Nb0.5TixV2Zr0.5 refractory complex concentrated alloys with different Ti contents (x = 0.4, 0.8, 1.2, and 1.6) are fabricated via vacuum arc melting. The effects of Ti on microstructurale evolution, density, and mechanical properties at room and elevated temperatures are investigated. The Al0.8Nb0.5TixV2Zr0.5 alloys are composed of a BCC solid solution matrix and a C14-Laves (hexagonal) phase, and the volume fraction of the BCC phase increases as the Ti content increases from 63.48% to 90.97%. The density decreases from 5.70 to 5.42 g/cm3, whereas the hardness first increases and then decreases in the range of 625.2 to 669.5 HV. The results of compression test at different temperatures show that the yield strength and deformability of the Al0.8Nb0.5TixV2Zr0.5 alloys first increases and then decreases, and that the alloys show good phase stability when the Ti content is 1.2. The compressive yield strength of Ti1.2 alloy is 1848 MPa at room temperature, 1507 MPa at 673 K, and 1068 MPa at 1073 K. The increase in yield strength is due to various strengthening mechanisms caused by the addition of Ti, including the solid-solution strengthening effect caused by severe lattice distortion, the decrease in the valence electron concentration, and the grain boundary strengthening effect caused by grain size reduction. The present study is an example of a systematic investigation into the effects of elements on the structure and properties of refractory complex concentrated alloys through alloy design, which is expected to facilitate the design of lightweight refractories and their compositions.

Porous medium-entropy (Zr0.25Ce0.25Hf0.25Y0.25)O2-δ ceramic with low thermal conductivity: Using aerogel structure as the precursor

The amorphous aerogel precursor with a BET-specific surface area of 203.58 m2/g was synthesized by sol-gel and CO2 supercritical drying using metal chlorides as cation source. It was then calcined at 950 °C to obtain a monolithic defective fluorite (Zr0.25Ce0.25Hf0.25Y0.25)O2-δ ceramic aerogel with a grain size of 20 nm and an ultra-low thermal conductivity of 0.054 W m−1 K−1 at room temperature. Bulk (Zr0.25Ce0.25Hf0.25Y0.25)O2-δ with porosity of 62.24–66.11% and flexural strength of 2.359–4.487 MPa were synthesized by pressing and sintering. The sintered porous (Zr0.25Ce0.25Hf0.25Y0.25)O2-δ ceramic has a low thermal diffusivity of 0.152–0.207 mm2/s and a thermal conductivity of 0.138–0.201 W m−1 K−1 with a thermal transfer behavior distinct from that of micro-grain ceramics, which is caused by the severe lattice distortion, porous structure, and nanoscale phonon boundary scattering.

Study on erosion wear characteristics of aero-compressor blades considering distortion degree

A Tabakoff model of a certain type of turboshaft engine compressor blade was established, and the effects of no, mild, moderate, and severe distortions on blade erosion pattern were obtained. Based on particle velocimetry and erosive wear experiments, the Tabakoff model parameters (k12, V1, V2, V3, and θ0) were obtained. The effect of four distortion degrees on blade erosion pattern and erosion rate was studied. With an increase in the distortion degree, the erosion area of the rotor blade pressure surface is found to move toward the leading edge and blade tip. The erosion area of the stator blade suction surface moves toward the leading edge and blade root, whereas that of the pressure surface moves toward the blade root.

Whole-Voltage-Range Solid-Solution Reaction in Layered Oxide Cathode of Sodium-Ion Batteries.

Layered manganese-based oxides (LMOs) are promising cathode materials for sodium-ion batteries (SIBs) due to their versatile structures. However, the Jahn-Teller effect of Mn3+ induces severe distortion of MnO6 octahedra, and the resultant low symmetry is responsible for the gliding of MnO2 layers and then inferior multiple-phase transitions upon Na+ extraction/insertion. Here, hexagonal P2-Na0.643 Li0.078 Mn0.827 Ti0.095 O2 is synthesized through the incorporation of Li and Ti into the distorted orthorhombic P'2-Na0.67 MnO2 to function as a phase-transition-free oxide cathode. It is revealed that Li in both the transition-metal and Na layers enhances the covalency of Mn-O bonds and allows degeneracy of Mn 3d eg orbitals to favor the formation of hexagonal phase, and the high strength of Ti-O bonds reduces the electrostatic interaction between Na and O for suppressed Na+ /vacancy rearrangements. These collectively lead to a whole-voltage-range solid-solution reaction between 1.8 and 4.3V with a small volume variation of 1.49%. This rewards its excellent cycling stability (capacity retention of 90% after 500 cycles) and rate capability (89 mAh g-1 at 2000mA g-1 ).

Underwater image enhancement method based on denoising diffusion probabilistic model

Underwater images often suffer from severe distortion, which seriously affects the image quality and the application. Current underwater image enhancement methods have poor generalization capability and cannot be adapted to all types of underwater images. In recent years, the diffusion model based on the denoising diffusion probabilistic model (DDPM) has achieved excellent results in various fields of computer vision. Inspired by the DDPM, an underwater image enhancement method based on the DDPM (UW-DDPM) was proposed in this paper. The UW-DDPM trained on paired datasets and utilized two U-Net networks to complete image denoising as well as image distribution transformation, which effectively improved the quality of underwater images. By testing on real underwater image datasets, UW-DDPM achieved better improvement in visual effects and evaluation metrics than the existing model.

Towards a new chalcopyrite high-performance thermoelectric semiconductor Cu3InSnSe5 by entropy engineering

A new semiconductor Cu3InSnSe5 is introduced by entropy driven alloying equimolar ratio CuInSe2 and Cu2SnSe3. Cu3InSnSe5 is a p-type semiconductor (Eg ∼0.41 eV) and crystallizes in the chalcopyrite structure with I4_2 m space group. Our density functional theory calculations show that Cu3InSnSe5 exhibits an electronic band structure with multiple valance band peaks, rendering a large density of state effective mass m* of 1.8 me. Therefore, Cu3InSnSe5 has a high power factor of 7.59 μW cm−1 K−2 at 773 K. In addition, Cu3InSnSe5 also has a low lattice thermal conductivity (0.34 W m−1 K−1 at 773 K) owing to its severe lattice distortion arose by entropy enhancement. As a result, the figure of merit reaches as high as 1.08 at 773 K for Cu3InSnSe5. Furthermore, electronic band engineering is adopted to enhance the carrier concentration and m* of Cu3InSnSe5 via the substitution of In for Sn, resulting in ∼28% enhancement in power factor, ∼21% increment in ZT (1.31 at 773 K), and ∼10% enhancement in average ZT (∼ 0.67 at 473 – 773 K) for Cu3In1.01Sn0.99Se5 compared with Cu3InSnSe5 itself. Our work shows Cu3InSnSe5 should be a promising candidate for thermoelectric power generation at medium temperature.

Superior cryogenic strength and ductility in VNbTa body-centered cubic medium-entropy alloys

In this study, the deformation behavior of an equiatomic VNbTa medium-entropy alloy with a BCC single phase is studied by tensile tests at cryogenic temperatures. The results show that the alloy presents a strong strain hardening capability, which leads to a high ultimate tensile strength of 1930 MPa while maintaining a high fracture elongation of ∼27%, without a ductile to brittle transition. The excellent cryogenic temperature mechanical properties of the present alloy are attributed to the cooperative of {112}〈111〉 deformation twins, dislocation interaction, and entanglement caused by the continuing cross-slip of dislocation. The localized severe lattice distortions caused by the large atomic size misfit of elements among Nb, Ta and V play a major role in the cross-slip of dislocation.

Burning questions: Experiments on the effects of charring on domestic and wild sorghum

Sorghum was first domesticated approximately 6000 years ago in the eastern Sahel region of Africa, but our understanding of its agricultural history is uneven due to the paucity of the available archaeobotanical evidence. Despite growing interest in the issue, sorghum response to fire exposure has been little investigated. In this paper, the resistance of six domesticated sorghum varieties (Sorghum bicolor) and one wild specimen (Sorghum arundinaceum) to charring was evaluated under oxidising and reduced oxygen conditions using temperatures ranging from 300 °C to 500 °C for 1–8 h. The experimental study in this work indicates that the maximum temperature wild sorghum can resist without severe distortion is around 300 °C, whereas domesticated varieties could resist up to 350 °C before becoming damaged beyond identification. Our findings suggest that resistance to temperature might represent an important bias for sorghum seed preservation, both in its wild and domesticated forms.

Group IV Complexes with Sterically Congested N-Aryl-adamantylcarbamidate Ligands.

Metalation of N-(2,6-dibenzhydryl-4-tolyl)adamantane-1-carboxamide (1, Ar*N(H)-C(O)-Ad) with M(NMe2)4 (M = Ti, Zr, Hf) yields amidate complexes Ar*N=C(Ad)-O-Ti(NMe2)3 (2) as well as bis(amidate) compounds (Ar*N=C(Ad)-O)2M(NMe2)2 (M = Zr (3), Hf (4)). In 2, the amidate ligand acts as a monodentate base via the oxygen atom with the Ti center in a slightly distorted tetrahedral environment. The steric requirement of the amidate ligand stabilizes the small coordination number of four of the Ti atom. In congeners 3 and 4, two bidentate amidate ligands exist in the coordination spheres, leading to hexacoordinate group IV metal atoms. The small bite angles of the Zr- and Hf-bound amidate ligands lead to severe distortion of the octahedral environments of the Zr and Hf centers. Titanium compound 2 is an unsuitable choice to catalyze hydrofunctionalization of alkynes with amines and phosphane oxides and despite the significantly smaller pKa value of the carboxylic amide, formation of carboxamide 1 is the dominant reaction upon addition of amines or phosphane oxides to release intramolecular steric strain introduced by the very bulky adamantylamidato ligand.

Development of novel isobaric tags enables accurate and sensitive multiplexed proteomics using complementary ions.

High-throughput quantitative analysis of the cells' proteomes across multiple conditions such as various perturbations and different time points is essential for gaining insights into treatment-induced biological responses or disease pathological states. The advancements in mass spectrometry instrumentation and isobaric labeling methods provided useful tools to help address such demands. However, the current widely adopted isobaric labeling methods such as tandem mass tag (TMT) and isobaric tags for relative and absolute quantitation (iTRAQ) are based on low-mass reporter ions, which are indistinguishable among different peptide analytes, to achieve relative quantification. Therefore, these methods intrinsically suffer from severe ratio distortion when analyzing complex samples due to peptide coelution and cofragmentation. Here, we developed a novel set of isobaric tags named dimethylated leucine complementary ion (DiLeuC) and relied on complementary ions for relative quantification, in which the complementary ions are the remanent peptide segments after fragmentation in the high-mass range. Since those residual peptide fragments are precursor-specific, they retain the relative abundance information in an interference-free manner even in a complex matrix environment. The quantification accuracy of our method was validated in a two-proteome model where the yeast proteome was spiked with a strong background human proteome as interference. In addition, we also applied this strategy to single-cell proteome analysis, demonstrating its potential utility for sensitive high-throughput quantitative proteomics.

Investigation of thermal and mechanical effects during electrically-assisted compression of CoCrFeNiW0.5 high entropy alloy

Electrically-assisted manufacturing (EAM) has many advantages than ambient temperature manufacturing and thermoforming for the building of hard-to-deform alloys. The EAM technique of High entropy alloys (HEAs), a newer alloy category, is an issue worth of research, especially the deformation mechanism in the process of EAM. In the paper, the electrically-assisted compressive mechanical behavior of CoCrFeNiW0.5 HEA composed of face centered cubic phase and μ phase precipitate was studied under current density and strain rate region of 0–40 A/mm2 and 0.0005 s−1-0.1 s−1, respectively. At high current density and strain rate, the reduction of yield stress is remarkable. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) techniques were utilized to analyze the effect of current density on the flow stress behaviors and microstructure evolution under plastic deformation. The results show that the introduced electric current enhances the movement and annihilation of dislocations as well as dynamic recovery, resulting in the continuous decrease of flow stress. Additionally, we can clearly observed that the dislocation-free ring or some very low dislocation density regions around the μ phase precipitates, that's because μ phase precipitate can lead to severe lattice distortion and thus increase the electron scattering, and then the local high temperature appeared around the defect regions due to local Joule heating effect, which is recognized as the principal reason leading to the significant decrease of mechanical properties during electrically-assisted compression.

Chemical complexity-changed deformation behavior of NiTi-based B2 low- to high-entropy intermetallic compounds: Atomistic simulations

Owing to the high chemical complexity and severe lattice distortion but still long-range ordered structure, the deformation behavior and defect activities of high-entropy intermetallic compounds are worth investigations. Hence in this study, the mechanical properties of NiTi-based low- to high-entropy intermetallic compounds were measured from different orientations at different temperatures simply by using nanoindentations, and compared with the structural evolution and defect activities suggested by molecular dynamics simulations. The deformation of the low-entropy intermetallic compound proceeded with regular martensitic transformation, followed by the heterogeneous nucleation of dislocations at the martensite/austenite interface and the subsequent long-distance gliding accompanied with sharp stress drops. With increasing temperature, a more intense shearing events and marked strength reduction were observed. In comparison, with the introduction of constitutional complexity, the martensitic transition was suppressed. Instead, the early homogeneous nucleation at a relatively small activation volume (acquired from indenting displacement bursts) and small-range activities of abundant defects mediated the smooth stress-strain response and uniform plastic deformation of the high-entropy intermetallic compound. At an elevated temperature, a similar deformation mechanism and the same level of strength were retained in the chemically complex alloy.

A novel hierarchical power allocation strategy considering severe wind power fluctuations for wind-storage integrated systems

The development of renewable energy dominated power system and the integration of large-scale wind-storage energy system are inevitable trends of the future society. This paper developed a new methodology of hierarchical power allocation strategy considering wind power fluctuation. A novel idea is presented that fully considers the fluctuation and energy proportion. Based on the Quartile Method (QM) and Hampel-Savitzky Golay (HSG) strategy, a layered-based method that considers the volatility interval to effectively overcome the limitations of a single strategy caused by severe volatility interval is proposed. Then, an improved power division method based on Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) and Dynamic Mode Decomposition (DMD) is proposed where CEEMDAN is used to decompose the Intrinsic Mode Function (IMF) of the remaining fluctuations. Furthermore, according to the required setting of energy proportion, DMD strategy is used for power fitting of the hybrid energy storage system (HESS). Through experimental verification, the hierarchical strategy proposed in this paper can effectively reduce the probability of severe volatility interval or distortion interval and ensure the sequence in the ideal interval. Moreover, the proposed CEEMDAN-DMD strategy can realize the power division according to the energy proportion demand. In model verification, the volatility improvement ζλ1min = 85.4766%. Set the energy demand ≥ 80%, the fitting energy proportion accounts for 87.7533%, which outperforms the traditional power division method. In addition, it is demonstrated that the theoretical method proposed in this paper is reliable and promising.

Seismic time-frequency masking for suppression of seismic speckle noise

Seismic speckle noise is the primary factor causing severe reflection distortions caused by small-scale near-surface scattering. As in the case of speckle noise in optics and acoustics, deterministic velocity model-building techniques cannot recover these heterogeneities which are much smaller than a wavelength. Conventional processing techniques struggle to perform when multiplicative noise remains unsuppressed. Although local and global stacking mitigates the effects of speckle noise, it leads to a severe loss of higher frequencies reducing the vertical resolution of the seismic data. The foundation for attacking speckle noise is a recently proposed mathematical model that includes two concurrent random multiplicative noise types: type 1 defining residual statics and type 2 describing random frequency-dependent phase perturbations that mimic small-scale near-surface scattering. Using this model, we have developed seismic time-frequency masking to suppress speckle noise on prestack data. The time-dependent and non-surface-consistent nature of scattering noise dictates window-based approaches borrowed from local stacking techniques. Separate manipulation of phase and amplitude spectra is achieved through modified time-frequency masking inspired by speech processing. A beamformed data set from local stacking is used as a guide for designing phase and amplitude masks that are directly applied to raw data in the time-frequency domain. The phase mask allows the restoration of coherency by repairing phase distortions caused by near-surface scattering. The amplitude mask corrects power spectrum (PS) distortions caused by multiplicative and additive noises. An amplitude mask is implemented using a data-driven minimum statistic approach that estimates the noise PS in each local window. The minimum statistics approach is adapted from speech processing using beamformed data as an initial signal estimate and as a guide to designing an improved amplitude mask. Synthetic and field data examples suggest significant improvements in coherency and signal-to-noise ratio after the suppression of multiplicative noise, which makes the data processable by conventional techniques subsequently.

An overview of microstructure, mechanical properties and processing of high entropy alloys and its future perspectives in aeroengine applications

Modern engineering applications continually strive to develop greater performance mechanical components with good microstructural stability, improved mechanical properties, corrosion resistance and decreased cost of repairing and maintenance. This necessitates the broad use of advanced high performance materials like high entropy alloys (HEAs). These alloys are created by combining five or more alloying elements in equal or substantial amount. About 5 to 35 at. % of the alloying element is present in HEAs. It is characterized primarily by greater entropy, slow diffusion, severe lattice distortion, and cocktail effects. Due to its advanced microstructural stability throughout a larger temperature span and for longer length of time, it demonstrates improved mechanical characteristics at ambient temperature, cryogenic temperature, and elevated temperature. The diversity of elemental contents and significantly higher mixing entropy of HEAs make them mechanically superior to classic metals and alloys. It also shows better strength to weight ratio. Hence, it qualifies as a possible structural and functional material for aeroengine applications. In this work, the studies on the HEAs are briefly reviewed. A basic explanation of the four core effects of HEAs is given. Discussion is held on microstructure and mechanical properties of HEAs. The processing routes for manufacturing of HEAs (arc melting, bridgman solidification, mechanical alloying and vapour deposition) are presented briefly. The influence of heat treatment on mechanical behavior and microstructure of HEAs is presented. The simulation approach of CALPHAD modeling for designing of HEAs is discussed briefly. The future scope for research and development of HEAs in aeroengine applications is briefed.

Numerical estimation via remeshing and analytical modeling of nonlinear elastic composites comprising a large volume fraction of randomly distributed spherical particles or voids

We investigate numerically via finite element (FE) simulations and analytically the nonlinear behavior of a soft matrix comprising a large volume fraction (up to 55%) of monodisperse spherical inclusions, which can be either rigid particles or voids. To address the issue of severe mesh distortion at large strains, we employ a successive remeshing and solution mapping technique that allows us to achieve a large macroscopic deformation, with the maximum attained stretch being at least two to three times when compared to that without remeshing. A general algorithm allowing to read complex arbitrary particle geometries is proposed and implemented allowing to remesh a finitely strained domain with randomly distributed inclusions of arbitrary shape. The present simulation results for a neo-Hookean elastic matrix filled with rigid particles show that the nonlinear stress–stretch uniaxial tension response can be well approximated by a neo-Hookean material with an effective shear modulus that depends on the volume fraction of the inclusions. Additionally, a study of the number of particles demonstrates that sixty four monodisperse spheres is a good compromise to reach accurate results for large deformations and maintain a reasonable CPU-time. The FE data serve as a powerful assessment tool for analytical homogenization models. Newly developed and existing models for small and large strains are proposed and assessed, respectively, for both rigid particles and voids. These results fill the gap for large volume fractions of inclusions and serve as a reference for the homogenization of the microstructures of interest.

Text Image Super-Resolution Guided by Text Structure and Embedding Priors

We aim to super-resolve text images from unrecognizable low-resolution inputs. Existing super-resolution methods mainly learn a direct mapping from low-resolution to high-resolution images by exploring low-level features, which usually generate blurry outputs and suffer from severe structure distortion for text parts, especially when the resolution is quite low. Both the visual quality and the readability will suffer. To tackle these issues, we propose a new text super-resolution paradigm by recovering with understanding. Specifically, we extract a text-embedding prior and a text-structure prior from the upsampled image by learning to understand the text. The two priors with rich structure information and text-embedding information are then used as auxiliary information to recover the clear text structure. In addition, we introduce a text-feature loss to guide the training for better text recognizability. Extensive evaluations on both screen and scene text image datasets show that our method largely outperforms the state-of-the-art in both visual quality and recognition accuracy.

Investigation of vacuum active brazing of (HfZrTiTaNb)C high-entropy carbide ceramic to Nb with TiZrCuNi filler alloy

Good metallurgical joining was carried out between (HfZrTiTaNb)C high-entropy carbide and Nb via 37.5Ti37.5Zr15Cu10Ni (wt.%) filler alloy. The microstructure of the joint was (HfZrTiTaNb)C/(Zr, Ti)C/α-Ti + β-Ti + (Zr, Ti)2(Cu, Ni)/Zr(s, s) + β(Ti, Nb) + Nb(s, s)/Nb. The generation of (Zr, Ti)C and β(Ti, Nb)+Nb(s, s) phases between the liquid phase and ceramic and Nb were vital to realize the joining. The constituent phases of the joint did not change with the variation of brazing process parameters. When the brazing temperature rose from 920 to 1000 °C, the thickness of the (Zr, Ti)C reaction layer increased by 0.2 μm, while it remained roughly unchanged as the holding time was extended from 1 to 30 min. This unusual interfacial evolution pattern could partially attribute to the unique properties of sluggish diffusion and severe lattice distortion of the high-entropy ceramic. With the increase of brazing process parameters, the shear strength of the joints showed a mountain peak characteristic of increasing and then decreasing, and the maximum value of 154 MPa was obtained at 960 °C for 5 min. The fracture took place in the brittle (Zr, Ti)2(Cu, Ni) phase, and then passed through the (Zr, Ti)C phase and the ceramic substrate.