A stretching apparatus capable of conducting tensile tests over a broad strain rate range (10-3-250 s-1) and a wide temperature range (-75-250 °C) has been designed for polymeric materials, in particular the polymeric films. Specifically, this stretching apparatus can be combined with in situ ultrasmall-, small-, and wide-angle x-ray scattering (USAXS/SAXS/WAXS) measurements. The sample stretching is achieved through the synchronized rotation of rolls, powered by servo motors.
View Article and Find Full Text PDFA steel belt casting equipment, weighing approximately ∼6-7 tons and measuring ∼5 m in length, has been designed and developed for simulating the industrial processing of polymer films and being combined with synchrotron radiation in situ x-ray scattering measurements. Through modification of its modules, it is feasible to implement two distinct film casting modes, namely the wet and the dry casting processes. The speed of a steel belt can span from 0.
View Article and Find Full Text PDFAethina tumida (small hive beetle, SHB) is a rapidly spreading invasive parasite of bee colonies. The olfactory system plays a key role in insect behavior, and odorant-binding proteins (OBPs) are involved in the first step of the olfactory signal transduction pathway and the detection of host volatiles. However, the olfactory mechanism of OBPs in SHB-localized bee colonies is unclear.
View Article and Find Full Text PDFAerobic digestion remains the preferred choice for small-scale wastewater treatment plants (WWTPs) in some developing countries, largely due to economic viability and operational simplicity. The escalating production of waste activated sludge (WAS) has prompted small-scale WWTPs to improve efficiency. To address this issue, this study employed an in-situ sulfite treatment as a non-intrusive method to augment aerobic digestion.
View Article and Find Full Text PDFWe performed a series of molecular dynamics simulations on monodisperse polymer melts to investigate the formation of shear banding. Under high shear rates, shear banding occurs, which is intimately accompanied by the entanglement heterogeneity. Interestingly, the same linear relationship between the end-to-end distance Ree and entanglement density Z is observed at homogeneous flow before the onset of shear banding and at the shear banding state, where Ree ∼ ln(Wi0.
View Article and Find Full Text PDFDuring the pupal-adult eclosion process of holometabolous insects, the old cuticle is shed and replaced by a completely different new cuticle that requires tanning and expansion, along with extensive extracellular matrix (ECM) remodeling. In vertebrates, matrix metalloproteinases (MMPs), a class of zinc-dependent endopeptidases, play key roles in regulating the ECM that surrounds cells. However, little is known about these extracellular proteinases available in insects.
View Article and Find Full Text PDFTuning 3D refractive indices of polymers is urgently needed for optical films, but it is quite challenging. Here, we proposed a simple constrained uniaxial stretch method that successfully tuned the 3D refractive indices in cellulose triacetate (TAC) films plasticized with triethyl citrate (TEC). Our results suggest that, under constrained uniaxial stretch, the main chains and side groups prefer to orientate in the stretch direction and the constrained direction, respectively.
View Article and Find Full Text PDFThe mechanical properties of polymer glass are determined by both intermolecular local packing structures and aligned intrachain configurations. These configurations involve multiple space scales, and the underlying mechanism is not well understood yet. By applying mechanical stimulation to cold-drawn polymer glasses, the present simulation work shows a one-to-one correspondence between arising retractive stress and the segment orientation parameter on the length scale of the intrachain connecting bond.
View Article and Find Full Text PDFMacromol Rapid Commun
September 2023
As a key component in laminated glass, plasticized polyvinyl butyral (PVB) interlayer is a kind of impact-resistant polymer material with high toughness. Recently, by using ultrasmall angle X-ray scattering (USAXS) technique, Stretch-induced phase-separated structure on the scale of hundreds of nanometers formed in plasticized PVB for the first time is reported. In this work, the multiscale relaxation behavior of plasticized PVB is further investigated.
View Article and Find Full Text PDFMass storage and removal in solids always play a vital role in technological applications such as modern batteries and neuronal computations. However, they were kinetically limited by the slow diffusional process in the lattice, which made it challenging to fabricate applicable conductors with high electronic and ionic conductivities at room temperature. Here, we proposed an acid solution/WO/ITO sandwich structure and achieved ultrafast H transport in the WO layer by interfacial job-sharing diffusion, which means the spatially separated transport of the H and e in different layers.
View Article and Find Full Text PDFA biaxial stretching device is designed and developed for the real-time structural measurements of polymer films. This device adopts a vertical layout to perform real-time x-ray scattering measurements. It has a maximum stretching ratio of 8 × 8 in two perpendicular directions.
View Article and Find Full Text PDFBackground: High-grade gliomas are treated following a standard protocol; however, tumor recurrence is almost inevitable. Recurrent high-grade gliomas have an extremely poor prognosis, and there are no clear treatment guidelines. In this stud, we evaluated the safety and effectiveness of intraoperative radiotherapy (IORT) for recurrent high-grade glioma.
View Article and Find Full Text PDFCellulose acetate (CA) based films are widely used in liquid crystal displays due to their outstanding transparency, and a certain orientation birefringence of CA films is required when they are used as retardation films. The regulation of orientation birefringence is usually from the perspective of stretch-induced orientation, while the effects of crystallization behaviors of CA films remain obscure. In this study, the roles of crystallization and orientation on the orientation birefringence of CA films were elucidated.
View Article and Find Full Text PDFBackground: The molting hormone 20-hydroxyecdysone (20E) plays a key role in insect development, metamorphosis, and reproduction. Previous studies have shown that ecdysteroid metabolism is regulated by a series of CYP genes in most of the insect species. However, the roles of these CYP genes in a Coleopteran beetle, Aethina tumida (small hive beetle, SHB) have not yet been explored.
View Article and Find Full Text PDFCost-effective, representative and spatial coverage sampling designs are required to monitor the effects of potentially toxic elements (PTEs) in the soil. This study aims to evaluate the minimum sample sizes and placement of soil sampling designs to monitor and characterize the spatial variation of the PTEs (Cu, Zn, Cd, Cr, Pb, and Ni) in the soils. However, there is no standardized approach for evaluating the optimum soil sample size and monitoring location because of the spatial heterogeneity of PTEs in the soil.
View Article and Find Full Text PDFThe sun (∼6,000 K) and outer space (∼3 K) are two significant renewable thermodynamic resources for human beings on Earth. The solar thermal conversion by photothermal (PT) and harvesting the coldness of outer space by radiative cooling (RC) have already attracted tremendous interest. However, most of the PT and RC approaches are static and monofunctional, which can only provide heating or cooling respectively under sunlight or darkness.
View Article and Find Full Text PDFU, Sr, Pb, Nd, and Hf isotope ratios can provide basic and important information of nuclear materials. We established a simple and efficient column chemistry method using nano-NaBiO as both oxidizer and adsorbent, to completely separate Ce from rare earth elements (REEs). This new method exhibited a high decontamination (Ce/Nd < 10) ability and was easy to conducted, thereby providing clear advantages compared to traditional liquid-liquid and solid phase micro-extraction techniques.
View Article and Find Full Text PDFThe general aspects of polymer crystallization under external flow, i.e., flow-induced crystallization (FIC) from fundamental theoretical background to multi-scale characterization and modeling results are presented.
View Article and Find Full Text PDFBrain transcriptional regulatory network for behavior demonstrates that brain gene expression in the honey bee can be accurately predicted from the expression transcription factors (TFs), but roles for specific TFs are less understood. Mushroom bodies (MBs) are important for learning, memory and sensory integration in the honey bee brain. A TFs, Mblk-1, expressed preferentially in the large-type Kenyon cells of the honeybee MBs is predicted to be involved in brain function by regulating transcription of its target genes in honey bee.
View Article and Find Full Text PDFis a parasite and predator of honeybee causing severe loss to the bee industry. No effective and environmentally friendly methods are available to control this pest at present. Chemosensory genes play key roles in insect behavior which can potentially be used as targets for developing environmentally friendly pest control agents.
View Article and Find Full Text PDFCurrent synthetic elastomers suffer from the well-known trade-off between toughness and stiffness. By a combination of multiscale experiments and atomistic simulations, a transparent unfilled elastomer with simultaneously enhanced toughness and stiffness is demonstrated. The designed elastomer comprises homogeneous networks with ultrastrong, reversible, and sacrificial octuple hydrogen bonding (HB), which evenly distribute the stress to each polymer chain during loading, thus enhancing stretchability and delaying fracture.
View Article and Find Full Text PDFTo deal with the drinking water safety caused by fluoride, a novel carboxylated polyacrylonitrile nanofibrous membrane (C-PAN NFM) is designed and fabricated massively for the first time by adopting synchronously biaxial stretching and carboxylation. The C-PAN NFM is composed of the layered stack structure by cross-linked nanofibers. Due to its high specific surface area, excellent hydrophilicity, a large amount of carboxyl and amine groups, C-PAN NFM owns high fluoride adsorption capacity and outstanding selectivity.
View Article and Find Full Text PDFBased on the widely studied poly(l-lactic acid) (PLLA) and polyethylene terephthalate (PET) that are brittle in their fully crystalline form, this Letter shows that they can be made to be super ductile, heat resistant and optically clear by creating nano-sized crystals while preserving the entanglement network. Atomic force microscopic images confirm the perceived nano-confined crystallization. Time-resolved X-ray scattering/diffraction measurements reveal the emergence of cold crystallization during either stress relaxation from large stepwise melt-stretching or annealing of pre-melt-stretched PLLA and PET above Tg.
View Article and Find Full Text PDFThe microstructural origin of the double yield points of metallocene linear low-density polyethylene (mLLDPE) precursor films has been studied with the assistance of the synchrotron radiation small- and wide-angle X-ray scattering (SAXS/WAXS). It has been shown that the microstructural origin of the double yield points is highly related to the initial orientation of the original precursor film. For less oriented mLLDPE precursor films, the rearrangement of lamellae and the appearance of the monoclinic phase are the microstructural origins of the first yield point.
View Article and Find Full Text PDFThe hierarchical structural evolution of natural rubber (NR) filled with different contents of nanoscale carbon black (CB) (10 phr-CB10 and 50 phr-CB50) after first loading and recovering for different times was investigated by X-ray nano-CT, wide-angle X-ray scattering (WAXS) and solid state NMR techniques. The CB filler structures as captured by X-ray nano-CT recover gradually with increasing recovering time, but the filler network with different CB contents shows dramatically different structure evolution. For CB10, limited by the filling content, CB particles mainly induces a hydrodynamic effect in spite of deformation or recovering.
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