Publications by authors named "Zhaoqiang Song"

The fracture behaviors of disulfide vitrimers are highly rate-dependent. Our investigation revealed that the temperature-dependent fracture behaviors of disulfide vitrimers cannot be entirely explained by a simple time-temperature superposition model. This Letter explores the impact of the dynamic nature of molecular defects on the temperature- and rate-dependent fracture behaviors of disulfide vitrimers.

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  • Creating safer secondary explosives that can be directly initiated by lasers is important, but it's tough to do without using sensitive primers.
  • Researchers developed spherical composites of CL-20, enhanced with nano aluminum and a graphene-based catalyst, to improve laser absorbance and reduce mechanical sensitivity.
  • These composites showed significantly higher critical impact energy and friction load, as well as improved laser absorbance in the near-infrared range, making them more effective for ignition with lower power lasers.
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  • Researchers developed a new method to create a composite film combining graphene and NiFeO using a laser-assisted technique that mimics popcorn-making, aiming to improve uniform distribution of nanoparticles.
  • This approach successfully prevents common issues like agglomeration and compositional changes that occur at high temperatures during processing.
  • The resulting film demonstrates excellent electrical conductivity, mechanical flexibility, and outstanding electromagnetic interference (EMI) absorption, making it promising for various commercial applications.
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  • Breast cancer becomes invasive when carcinoma cells break through the basement membrane (BM), a barrier that separates the tumor from surrounding tissue.
  • Researchers created a 3D model to study how multiple cancer cells invade the BM collectively, finding that they use a combination of proteases and mechanical forces without relying on invadopodia.
  • The study reveals that the invasion process involves both the expansion of cell volume, which stretches the BM, and local forces that help breach it, highlighting a key mechanism in cancer metastasis.
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Nonpenetrating traumatic brain injuries (TBIs) are linked to cavitation. The structural organization of the brain makes it particularly susceptible to tears and fractures from these cavitation events, but limitations in existing characterization methods make it difficult to understand the relationship between fracture and cavitation in this tissue. More broadly, fracture energy is an important, yet often overlooked, mechanical property of all soft tissues.

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  • Researchers discovered a unique fracture behavior in polymer networks with covalent adaptable bonds, where crack propagation is influenced by the dynamic nature of these bonds and is not steady over time.
  • Traditional fracture theories, which assume steady-state conditions, cannot adequately explain this behavior, leading to the development of a new framework that accommodates time-dependent crack growth.
  • Through experimental modeling, the study identifies two key parameters—Weissenberg number and an extension parameter (Z)—that govern how cracks form and grow in these transient networks, allowing for the possibility to “program” crack behavior through manipulation of loading conditions.
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We investigate the rate-dependent fracture of vitrimers by conducting a tear test. Based on the relationship between the fracture energy and the thickness of vitrimer films, we, for the first time, obtain the intrinsic fracture energy and bulk dissipation of vitrimers during crack extension. The intrinsic fracture energy strongly depends on tear speed, and such dependence can be well explained by Eyring theory.

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The majority of 3D-printed biodegradable biomaterials are brittle, limiting their potential application to compliant tissues. Poly (glycerol sebacate) acrylate (PGSA) is a synthetic biodegradable and biocompatible elastomer, compatible with light-based 3D printing. In this work we employed digital-light-processing (DLP)-based 3D printing to create a complex PGSA network structure.

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Liquid crystal elastomer (LCE) is a newly emerging soft actuating material that has been extensively explored for building novel soft robots and diverse active devices, thanks to its large actuation stress and strain, high work density, and versatile actuation modes. However, there have also been several widely recognized limitations of LCE-based actuators for practical applications, including slow response and narrow range of operation temperature. Herein, we develop fluid-driven disulfide LCE actuators through facile laminate manufacturing enabled by a dynamic bond exchange reaction.

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Bioinspired architectural design for composites with much higher fracture resistance than that of individual constituent remains a major challenge for engineers and scientists. Inspired by the survival war between the mantis shrimps and abalones, we design a discontinuous fibrous Bouligand (DFB) architecture, a combination of Bouligand and nacreous staggered structures. Systematic bending experiments for 3D-printed single-edge notched specimens with such architecture indicate that total energy dissipations are insensitive to initial crack orientations and show optimized values at critical pitch angles.

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Twisted or oscillated plywood structure can be often found in biological composites such as claws of lobsters, bone of mammals, dactyl club of mantis shrimps, and exoskeleton of beetles, which exhibits a combination of high stiffness, high fracture toughness and low density. However, there lacks a quantitative understanding of the relationship between the fracture toughness of the composite and its internal geometry. In this article, we propose that a combination of crack tilting and crack bridging determines the effective fracture toughness of the fiber-reinforced composite with the plywood structure.

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  • Researchers are exploring graphene-based artificial nacres that could outperform natural nacre in terms of mechanical properties.
  • Studies indicate that an optimal level of crosslink density—related to the concentration of surface functional groups—leads to the best performance in these materials.
  • A hybrid model combining nonlinear shear-lag theory and atomistic simulations shows that the balance of various factors at this optimal density maximizes strength and toughness, while adjustments to graphene sheet size do not further improve mechanical properties.
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  • The study investigated how two rice varieties respond to salt stress through physiological and biochemical analysis.
  • The tolerant variety (T07339) showed minimal growth inhibition compared to the sensitive variety (L7), which displayed significant salt injury after just three days.
  • Proteomic analysis revealed differences in protein expression between the two varieties, highlighting four proteins with distinct patterns that contribute to the improved salt tolerance in T07339.
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Various methods have been exploited to replicate nacre features into artificial structural materials with impressive structural and mechanical similarity. However, it is still very challenging to produce nacre-mimetics in three-dimensional bulk form, especially for further scale-up. Herein, we demonstrate that large-sized, three-dimensional bulk artificial nacre with comprehensive mimicry of the hierarchical structures and the toughening mechanisms of natural nacre can be facilely fabricated via a bottom-up assembly process based on laminating pre-fabricated two-dimensional nacre-mimetic films.

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Small brown planthopper (SBPH) and rice stripe virus (RSV) disease transmitted by SBPH cause serious damage to rice (Oryza sativa L.) in China. In the present study, we screened 312 rice accessions for resistance to SBPH.

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