Proc Natl Acad Sci U S A
January 2025
The strength-ductility trade-off exists ubiquitously, especially in brittle intermetallic-containing multiple principal element alloys (MPEAs), where the intermetallic phases often induce premature failure leading to severe ductility reduction. Hierarchical heterogeneities represent a promising microstructural solution to achieve simultaneous strength-ductility enhancement. However, it remains fundamentally challenging to tailor hierarchical heterostructures using conventional methods, which often rely on costly and time-consuming processing.
View Article and Find Full Text PDFBackground: Radiotherapy is a primary local treatment for tumors, yet it may lead to complications such as radiation-induced heart disease (RIHD). Currently, there is no standardized approach for preventing RIHD. Dexmedetomidine (Dex) is reported to have cardio-protection effects, while its role in radiation-induced myocardial injury is unknown.
View Article and Find Full Text PDFTwinning is profuse in bcc transition metals (TMs) except bulk W and Mo. However, W and Mo nanocrystals surprisingly exhibit twinning during room temperature compression, which is completely unexpected as established nucleation mechanisms are not viable in them. Here, we reveal the physical origin of deformation twinning in W and Mo.
View Article and Find Full Text PDFTrajectory prediction is an essential task in many applications, including autonomous driving, robotics, and surveillance systems. In this paper, we propose a novel trajectory prediction network, called TFBNet (trajectory feature-boosting network), that utilizes trajectory feature boosting to enhance prediction accuracy. TFBNet operates by mapping the original trajectory data to a high-dimensional space, analyzing the change rules of the trajectory in this space, and finally aggregating the trajectory goals to generate the final trajectory.
View Article and Find Full Text PDFStress graphitization is a unique phenomenon at the carbon nanotube (CNT)-matrix interfaces in CNT/carbon matrix (CNT/C) composites. A lack of fundamental atomistic understanding of its evolution mechanisms and a gap between the theoretical and experimental research have hindered the pursuit of utilizing this phenomenon for producing ultrahigh-performance CNT/C composites. Here, we performed reactive molecular dynamics simulations along with an experimental study to explore stress graphitization mechanisms of a CNT/polyacrylonitrile (PAN)-based carbon matrix composite.
View Article and Find Full Text PDFBiomed Microdevices
February 2023
Renal tubule chips have emerged as a promising platform for drug nephrotoxicity testing. However, the reported renal tubule chips hardly replicate the unique structure of renal tubules with thick proximal and distal tubules and a thin loop of Henle. In this study, we developed a fully structured scaffold-free vascularized renal tubule on a microfluidic chip.
View Article and Find Full Text PDFRopivacaine, a common local anesthetic in the clinic, has anti-proliferative and pro-apoptotic effects in numerous cancers, however, the underlying regulatory mechanism of ropivacaine in hepatocellular carcinoma remains unclear. In the current study, human HepG2 cells were stimulated with different ropivacaine concentrations. Cell Counting Kit-8 assay, cell colony formation, and cell cycle were used to monitor cell viability.
View Article and Find Full Text PDFWe investigated the microstructures of carbon nanotube (CNT) films and the effect of CNT length on their mechanical performance. 230 μm-, 300 μm-, and 360 μm- long CNTs were grown and used to fabricate CNT films by a winding process. Opposite from the length effect on CNT fibers, it has been found that the mechanical properties of the CNT films decrease with increasing CNT length.
View Article and Find Full Text PDFThe surface nano-crystallization of NiFeCoMoV medium-entropy alloy was realized by rotationally accelerated shot peening (RASP). The average grain size at the surface layer is ~37 nm, and the nano-grained layer is as thin as ~20 μm. Transmission electron microscopy analysis revealed that deformation twinning and dislocation activities are responsible for the effective grain refinement of the high-entropy alloy.
View Article and Find Full Text PDFUltrastrong materials can notably help with improving the energy efficiency of transportation vehicles by reducing their weight. Grain refinement by severe plastic deformation is, so far, the most effective approach to produce bulk strong nanostructured metals, but its scaling up for industrial production has been a challenge. Here, we report an ultrastrong (2.
View Article and Find Full Text PDFLow plasticity has been a major issue for the application of Mg alloys. Here, based on the generalized stacking fault energy curves and Arrhenius equation, we systematically study alloying effects on the stacking fault energies and the activation probability of basal and non-basal 〈a〉, and pyramidal 〈c + a〉 slip systems in twenty-one Mg alloys. Our results reveal that activation of 〈c + a〉 slip systems on pyramidal II plane can significantly improve the plasticity.
View Article and Find Full Text PDFCarbon nanotube (CNT) fiber has not shown its advantage as next-generation light-weight conductor due to the large contact resistance between CNTs, as reflected by its low conductivity and ampacity. Coating CNT fiber with a metal layer like Cu has become an effective solution to this problem. However, the weak CNT-Cu interfacial bonding significantly limits the mechanical and electrical performances.
View Article and Find Full Text PDFCircadian disruption has been implicated in tumour development, but the underlying mechanism remains unclear. Here, we show that the molecular clockwork within malignant human pancreatic epithelium is disrupted and that this disruption is mediated by miR-135b-induced BMAL1 repression. miR-135b directly targets the BMAL1 3'-UTR and thereby disturbs the pancreatic oscillator, and the downregulation of miR-135b is essential for the realignment of the cellular clock.
View Article and Find Full Text PDFAl(1060)/Mg(AZ31)/Al(1060) multilayered composite was successfully produced using an accumulative roll bonding (ARB) process for up to four cycles at an elevated temperature (400 °C). The microstructure evolution of the composites and the bonding characteristics at the interfaces between Al and Mg layers with increasing ARB cycles were characterized through optical microscopy, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). It was found that the grains of Al and Mg layers were significantly refined and Al₃Mg₂ and Al Mg intermetallic compound layers formed at the Al/Mg bonding interfaces.
View Article and Find Full Text PDFIn this study, a kind of Al-TiB₂/TiC in situ composite was successfully prepared using the melt reaction method and the accumulative roll-bonding (ARB) technique. The microstructure evolution of the composites with different deformation treatments was characterized using field emission scanning electron microscopy (FESEM) and a transmission electron microscope (TEM). The mechanical properties of the Al-TiB₂/TiC in situ composite were also studied with tensile and microhardness tests.
View Article and Find Full Text PDFHigh-carbon martensite steels (with C > 0.5 wt.%) are very hard but at the same time as brittle as glass in as-quenched or low-temperature-tempered state.
View Article and Find Full Text PDFNanostructured (NS) and ultrafine-grained (UFG) materials have high strength and relatively low ductility. Their toughness has not been comprehensively investigated. Here we report the Charpy impact behavior and the corresponding microstructural evolutions in UFG Cu with equi-axed and elongated grains which were prepared by equal channel angular pressing (ECAP) for 2 and 16 passes at room temperature.
View Article and Find Full Text PDFScanning electron microscopy transmission Kikuchi diffraction is able to identify twins in nanocrystalline material, regardless of their crystallographic orientation. In this study, it was employed to characterize deformation twins in Cu/10 wt % Zn processed by high-pressure torsion. It was found that in 83% of grains containing twins, at least one twin intersects with a triple junction.
View Article and Find Full Text PDFIt has been more than a decade since the thermal conductivity of vertically aligned carbon nanotube (VACNT) arrays was reported possible to exceed that of the best thermal greases or phase change materials by an order of magnitude. Despite tremendous prospects as a thermal interface material (TIM), results were discouraging for practical applications. The primary reason is the large thermal contact resistance between the CNT tips and the heat sink.
View Article and Find Full Text PDFObjective: To compare the effect of propofol and sevoflurane on perioperative immunity and surgical outcomes in patients undergoing laparoscopic radical resection of colorectal cancer.
Methods: During September 2012 to April 2014 in Sir Run Run Shaw Hospital, thirty patients scheduled for laparoscopic colorectal cancer radical resection were randomly assigned into two groups: propofol TCI anesthesia and sevoflurane inhale anesthesia. Venous blood was taken before induction, on finishing the surgery and 24 h after surgery for lymphocyte subtype study by flow cytometry.
Proc Natl Acad Sci U S A
November 2015
Grain refinement can make conventional metals several times stronger, but this comes at dramatic loss of ductility. Here we report a heterogeneous lamella structure in Ti produced by asymmetric rolling and partial recrystallization that can produce an unprecedented property combination: as strong as ultrafine-grained metal and at the same time as ductile as conventional coarse-grained metal. It also has higher strain hardening than coarse-grained Ti, which was hitherto believed impossible.
View Article and Find Full Text PDFIn this work, we present large scale, ultralight aligned carbon nanotube (CNT) structures which have densities an order of magnitude lower than CNT arrays, have tunable properties and exhibit resiliency after compression. By stacking aligned sheets of carbon nanotubes and then infiltrating with a pyrolytic carbon (PyC), resilient foam-like materials were produced that exhibited complete recovery from 90% compressive strain. With density as low as 3.
View Article and Find Full Text PDFIn order to maximize the carbon nanotube (CNT) buckypaper properties, it is critical to improve their alignment and reduce their waviness. In this paper, a novel approach, microcombing, is reported to fabricate aligned CNT films with a uniform structure. High level of nanotube alignment and straightness was achieved using sharp surgical blades with microsized features at the blade edges to comb single layer of CNT sheet.
View Article and Find Full Text PDFAssembly of carbon nanotubes (CNTs) in effective and productive ways is of vital importance to their application. Recent progress in synthesis of CNTs has inspired new strategies for utilizing the unique physiochemical properties of CNTs in macroscale materials and devices. Assembling CNTs by dry processes (e.
View Article and Find Full Text PDF