Strain-hardening (the increase of flow stress with plastic strain) is the most important phenomenon in the mechanical behaviour of engineering alloys because it ensures that flow is delocalized, ...enhances tensile ductility and inhibits catastrophic mechanical failure
. Metallic glasses (MGs) lack the crystallinity of conventional engineering alloys, and some of their properties-such as higher yield stress and elastic strain limit
-are greatly improved relative to their crystalline counterparts. MGs can have high fracture toughness and have the highest known 'damage tolerance' (defined as the product of yield stress and fracture toughness)
among all structural materials. However, the use of MGs in structural applications is largely limited by the fact that they show strain-softening instead of strain-hardening; this leads to extreme localization of plastic flow in shear bands, and is associated with early catastrophic failure in tension. Although rejuvenation of an MG (raising its energy to values that are typical of glass formation at a higher cooling rate) lowers its yield stress, which might enable strain-hardening
, it is unclear whether sufficient rejuvenation can be achieved in bulk samples while retaining their glassy structure. Here we show that plastic deformation under triaxial compression at room temperature can rejuvenate bulk MG samples sufficiently to enable strain-hardening through a mechanism that has not been previously observed in the metallic state. This transformed behaviour suppresses shear-banding in bulk samples in normal uniaxial (tensile or compressive) tests, prevents catastrophic failure and leads to higher ultimate flow stress. The rejuvenated MGs are stable at room temperature and show exceptionally efficient strain-hardening, greatly increasing their potential use in structural applications.
Background
This study aimed to compare sequential treatment by transcatheter arterial chemoembolization (TACE) and percutaneous radiofrequency ablation (RFA) with partial hepatectomy for ...hepatocellular carcinoma (HCC) within the Milan criteria.
Methods
In a randomized clinical trial, patients with HCC within the Milan criteria were included and randomized 1 : 1 to the partial hepatectomy group or the TACE + RFA group. The primary outcome was overall survival and the secondary outcome was recurrence‐free survival.
Results
Two hundred patients were enrolled. The 1‐, 3‐ and 5‐year overall survival rates were 97·0, 83·7 and 61·9 per cent for the partial hepatectomy group, and 96·0, 67·2 and 45·7 per cent for the TACE + RFA group (P = 0·007). The 1‐, 3‐ and 5‐year recurrence‐free survival rates were 94·0, 68·2 and 48·4 per cent, and 83·0, 44·9 and 35·5 per cent respectively (P = 0·026). On Cox proportional hazard regression analysis, HBV‐DNA (hazard ratio (HR) 1·76; P = 0·006), platelet count (HR 1·00; P = 0·017) and tumour size (HR 1·90; P < 0·001) were independent prognostic factors for recurrence‐free survival, and HBV‐DNA (HR 1·61; P = 0·036) was a risk factor for overall survival. The incidence of complications in the partial hepatectomy group was higher than in the TACE + RFA group (23·0 versus 11·0 per cent respectively; P = 0·024).
Conclusion
For patients with HCC within the Milan criteria, partial hepatectomy was associated with better overall and recurrence‐free survival than sequential treatment with TACE and RFA. Registration number: ACTRN12611000770965 (http://www.anzctr.org.au/).
Partial hepatectomy better
Quasi-periodicity of Zpan0 Zhou, W.
Acta mathematica Hungarica,
2023/8, Letnik:
170, Številka:
2
Journal Article
Recenzirano
Let
p
a
be a prime power and
n
0
a square-free number. We prove that any complementing pair in a cyclic group of order
p
a
n
0
is quasi-periodic, with one component decomposable by the the subgroup ...of order
p
. The proof is by induction and reduction since the presence of the square-free factor
n
0
allows us to perform a Tijdeman decomposition. We also give an explicit example to show that
Z
72
is the smallest cyclic group that fails to have the strong Tijdeman property.
The complex interaction between the Indian Ocean dipole (IOD) and El Niño–Southern Oscillation (ENSO) is further investigated in this study, with a focus on the impacts of the IOD on ENSO in the ...subsequent year ENSO(+1). The interaction between the IOD and the concurrent ENSO ENSO(0) can be summarized as follows: ENSO(0) can trigger and enhance the IOD, while the IOD can enhance ENSO(0) and accelerate its demise. Regarding the impacts of IOD(0) on the subsequent ENSO(+1), it is revealed that the IOD can lead to anomalous SST cooling patterns over the equatorial Pacific after the winter following the IOD, indicating the formation of a La Niña–like pattern in the subsequent year. While the SST cooling tendency associated with a positive IOD is attributable primarily to net heat flux (thermodynamic processes) from autumn to the ensuing spring, after the ensuing spring the dominant contribution comes from oceanic processes (dynamic processes) instead. From autumn to the ensuing spring, the downward shortwave flux response contributes the most to SST cooling over the central and eastern Pacific, due to the cloud–radiation–SST feedback. From the ensuing winter to the ensuing summer, changes in latent heat flux (LHF) are important for SST cooling, indicating that the release of LHF from the ocean into the atmosphere increases due to strong evaporation and leads to SST cooling through the wind–evaporation–SST feedback. The wind stress response and thermocline shoaling verify that local Bjerknes feedback is crucial for the initiation of La Niña in the later stage.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Laser-based additive manufacturing has attracted much attention as a promising 3D printing method for metallic components in recent years. However, surface roughness of additive manufactured ...components has been considered as a challenge to achieve high performance. In this work, we demonstrate the capability of fiber laser in polishing rough surface of additive manufactured Ti-based alloys as Ti-6Al-4V and TC11. Both as-received surface and laser-polished surfaces as well as cross-section subsurfaces were analyzed carefully by White-Light Interference, Confocal Microscope, Focus Ion Beam, Scanning Electron Microscopy, Energy Dispersive Spectrometer, and X-ray Diffraction. Results revealed that as-received Ti-based alloys with surface roughness more than 5µm could be reduce to less than 1µm through laser polishing process. Moreover, microstructure, microhardness and wear resistance of laser-polished zone was investigated in order to examine the thermal effect of laser polishing processing on the substrate of additive manufactured Ti alloys. This proof-of-concept process has the potential to effectively improve the surface roughness of additive manufactured metallic alloy by local polishing method without damage to the substrate.
•Laser polishing has been demonstrated as an effective method to polish laser additive manufactured Ti alloy surface.•Laser polishing smooths surface morphology by re-melting without altering or affecting bulk properties with high automation.•Original dual-phase structure of Ti alloy transformed to single phase under non-equilibrium condition after laser polishing.•After laser polishing, surface microhardness and wear resistance has been enhanced.
The Hall effect, which originates from the motion of charged particles in magnetic fields, has deep consequences for the description of materials, extending far beyond condensed matter. Understanding ...such an effect in interacting systems represents a fundamental challenge, even for small magnetic fields. In this work, we used an atomic quantum simulator in which we tracked the motion of ultracold fermions in two-leg ribbons threaded by artificial magnetic fields. Through controllable quench dynamics, we measured the Hall response for a range of synthetic tunneling and atomic interaction strengths. We unveil a universal interaction-independent behavior above an interaction threshold, in agreement with theoretical analyses. The ability to reach hard-to-compute regimes demonstrates the power of quantum simulation to describe strongly correlated topological states of matter.
Our recent efforts in developing electrocatalysts for ethanol oxidation reaction are focused on the ternary Pt–Rh–SnO2 catalysts due to their superior performance in splitting CC bond and the ability ...to fully oxidize ethanol to CO2. This work reports on the role of Rh from studies of the well-defined Rh(111) single-crystal and a series of carbon-supported nanoparticle catalysts for the electrooxidation of ethanol. A comparative study of supported nanocatalysts was carried out and their activity for ethanol oxidation decreased in the order of PtRhSnO2>PtSnO2>Pt>PtRh>Rh>RhSnO2. In situ infrared reflection–absorption spectroscopy studies showed that the catalysts’ selectivity toward ethanol total oxidation to CO2 decreased in the order of: PtRhSnO2∼RhSnO2>PtRh>Pt>PtSnO2∼Rh, verifying the role of Rh in breaking the CC bond, and the roles of the two other constituents, SnO2 and Pt, that facilitate the oxidation of the reaction intermediates and lessen their bonding to Rh. These results help understanding the role of Rh and SnO2 in the catalytic oxidation of ethanol and provide insights for designing catalysts with improved propeties.
•Develope a BN model to evaluate probability of third-party damage to pipelines.•Apply expectation-maximization algorithm to learn parameters of the BN model.•Demonstrate the effectiveness of ...parameter learning using real-world TPD datasets.•Provide a data-driven means to improve the pipeline integrity management for TPD.
Damage caused by third-party excavation is one of the leading threats to the structural integrity of underground energy pipelines. Based on fault tree models reported in the literature, the present study develops a Bayesian network (BN) model to estimate the probability of a given pipeline being hit by third-party excavations by taking into account common protective and preventative measures. The Expectation-Maximization (EM) algorithm in the context of the parameters learning is employed to learn the parameters of the BN model from datasets that consist of individual cases of third-party activities but with missing information. The effectiveness of the parameter learning for the developed Bayesian network is demonstrated by a numerical example involving simulated datasets of third-party activities and a case study using real-world datasets obtained from a major pipeline operator in Canada. The BN model and EM-based parameter learning proposed in this study allow pipeline operators to estimate the probability of hit by efficiently taking into account historical third-party excavation records in an objective, efficient manner.
Abstract
A large repulsion between particles in a quantum system can lead to their localization, an effect responsible for the Mott insulator phases in strongly correlated materials. In a system with ...multiple orbitals, an orbital-selective Mott insulator can form, where electrons in some orbitals are predicted to localize while others remain itinerant. Here we demonstrate a more general version of this phenomenon by observing flavour-selective localization in an atom-based quantum simulator. Our experiment realizes Fermi–Hubbard models with an SU(3) symmetry that can be broken using a tunable coupling between flavours. We observe an enhancement of the localization associated with a selective Mott transition and the emergence of flavour-dependent correlations. Our realization of flavour-selective Mott physics demonstrates the potential of cold atoms to simulate interacting multicomponent materials such as superconductors and topological insulators.
A succession of technological advances over the past decade have enabled researchers to chart maps of histone modifications and related chromatin structures with increasing accuracy, ...comprehensiveness and throughput. The resulting data sets highlight the interplay between chromatin and genome function, dynamic variations in chromatin structure across cellular conditions, and emerging roles for large-scale domains and higher-ordered chromatin organization. Here we review a selection of recent studies that have probed histone modifications and successive layers of chromatin structure in mammalian genomes, the patterns that have been identified and future directions for research.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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