Effective manipulation of phonons is crucial to modern energy‐information science and technologies but limited by the charge neutral and spinless nature of phonons. Recently, novel quantum concepts, ...including Berry phase, topology, and pseudospin, are introduced to phonon systems, providing fundamentally new routes to control phonons, opening an emerging field of “topological phononics.” Here, the basic concepts of Berry phase, topology, and pseudospin for phonons are introduced. Also, recent research progresses on various phononic topological states are reviewed, including phononic Su‐Schrieffer‐Heeger‐like states in 1D, quantum anomalous Hall‐like states, quantum valley Hall‐like states, and quantum spin Hall‐like states in 2D, and phononic Weyl points, nodal lines, and topological insulators in 3D. In addition to the fundamental models, material realizations and potential applications of topological phononics are comprehensively presented.
Phononic topological states are comprehensively discussed, including Su‐Schrieffer‐Heeger‐like states in 1D, quantum anomalous/valley/spin Hall‐like states in 2D, and phononic topological insulators and topological semimetals in 3D. An overview of topological phononics from fundamental models to real materials is also provided, followed by an outlook on future experiments and potential applications of this emerging research field.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The power conversion efficiencies (PCEs) of flexible organic solar cells (OSCs) still lag behind those of rigid devices and their mechanical stability is unable to meet the needs of flexible ...electronics at present due to the lack of a high‐performance flexible transparent electrode (FTE). Here, a so‐called “welding” concept is proposed to design an FTE with tight binding of the upper electrode and the underlying substrate. The upper electrode consisting of solution‐processed Al‐doped ZnO (AZO) and silver nanowire (AgNW) network is well welded by utilizing the capillary force effect and secondary growth of AZO, leading to a reduction of the AgNWs junction site resistance. Meanwhile, the poly(ethylene terephthalate) is modified by embedding the AgNWs, which are then used to link with the AgNWs in the upper hybrid electrode, thus enhancing the adhesion of the electrode to the substrate. By this welding strategy, critical bottleneck issues relating to the FTEs in terms of optoelectronic and mechanical properties are comprehensively addressed. The single‐junction flexible OSCs based on this welded FTE show a high performance, achieving a record high PCE of 15.21%. In addition, the PCEs of the flexible OSCs are less influenced by the device area and display robust bending durability even under extreme test conditions.
A “welding” transparent flexible electrode, with respect to both the upper electrode and the underlying substrate, for fabricating high‐performance flexible OSCs is proposed, resulting in a record power conversion efficiency of single‐junction flexible organic solar cells (OSCs) with excellent mechanical properties.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Solution processable flexible transparent electrodes (FTEs) are urgently needed to boost the efficiency and mechanical stability of flexible organic solar cells (OSCs) on a large scale. However, how ...to balance the optoelectronic properties and meanwhile achieve robust mechanical behavior of FTEs is still a huge challenge. Silver nanowire (AgNW) electrodes, exhibiting easily tuned optoelectronic/mechanical properties, are attracting considerable attention, but their poor contacts at the junction site of the AgNWs increase the sheet resistance and reduce mechanical stability. In this study, an ionic liquid (IL)-type reducing agent containing Cl– and a dihydroxyl group was employed to control the reduction process of silver (Ag) in AgNW-based FTEs precisely. The Cl– in the IL regulates the Ag+ concentration through the formation and dissolution of AgCl, whereas the dihydroxyl group slowly reduces the released Ag+ to form metal Ag. The reduced Ag grew in situ at the junction site of the AgNWs in a twin-crystal growth mode, facilitating an atomic-level contact between the AgNWs and the reduced Ag. This enforced atomic-level contact decreased the sheet resistance, and enhanced the mechanical stability of the FTEs. As a result, the single-junction flexible OSCs based on this chemically welded FTE achieved record power conversion efficiencies of 17.52% (active area: 0.062 cm2) and 15.82% (active area: 1.0 cm2). These flexible devices also displayed robust bending and peeling durability even under extreme test conditions.
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IJS, KILJ, NUK, PNG, UL, UM
Few studies have focused on evaluating regular surface roughness and its effect on interfacial shear behavior of the red clay – concrete interface. This paper presents the results of a series of ...laboratory large-scale direct shear tests conducted using different types of red clay – concrete interfaces. The objective is to examine the effect of surface roughness on these types of soil–concrete interfaces. In the smooth-interface tests, the measured peak and residual shear strength values are very close to each other, with no observed shear dilation. The surface roughness is found to have a remarkable effect on the interfacial shear strength and shear behavior, with the shear strength increasing with increased surface roughness level. The shear dilation is likely to occur on rougher interfaces under lower confining pressure due to the behavior of compressed clay matrices. Owing to the clay matrix’s cohesion and friction, the interfacial shear strength on rough interfaces consists of cohesive and frictional forces between the clay and concrete surfaces. The friction angle value is observed to fluctuate between the clay’s friction angle and the smooth interface’s friction angle. This can be related to the position change of the shear failure slip plane. The confining pressure and surface roughness could change the shear failure plane’s position on the interface. Furthermore, the red clay – structure interface is usually known as the weakest part in the mechanical safety assessment.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Existing studies reporting on the levels of physical fitness among college students used relatively few fitness tests as a reflection of physical fitness, which could not comprehensively evaluate the ...levels of physical fitness. Thus, the current study aimed to investigate the cross-sectional relationship between body mass index (BMI) and a physical fitness index (PFI) based on six indicators of fitness in Chinese college students.
Anthropometric measurements and six measures of physical fitness (Vital capacity, 50-m sprint, sit and reach, standing long jump, 800/1000-m run, pull-up/bent-leg sit-up) were measured. BMI was calculated to classify individuals into underweight, normal weight, overweight, and obesity groups. Z-scores based on sex-specific mean and standard deviation were calculated, and the sum of z-scores for the six fitness tests was used as a PFI. Three models (a linear regression model, polynomial regression model with a second-order BMI term and a restricted cubic spline regression model) were fitted to discuss the potential relation between BMI and PFI. We compared the models using Akaike Information Criterion (AIC) and R square.
Totally, 8548 freshmen from the years 2014 to 2016 in a medical college completed the physical fitness tests. There was a decreasing trend of physical fitness index from the years 2014 to 2016 (P for trend < 0.01). More male than female students were overweight or obese (23.5% vs. 11.9%), but more female than male students were normal weight (74.7% vs. 64.8%). A restricted cubic spline regression model was superior to linear and polynomial regression model with lower AIC and higher R square.
The relationships between BMI and PFI in college students were non-linear. Underweight, overweight and obese students had poorer performance in physical fitness index than normal weight students. Future prospective, longitudinal cohort studies to identify the causal relations and potential mechanism in a good manner are required.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The central Yunnan sub-block is an important channel for southeast migration of materials in the Qinghai-Xizang Plateau, and therefore a key area to study tectonic movement and deformation. In this ...study, a three-dimensional electrical structure of the crust and upper mantle lithosphere was derived from magnetotelluric data inversion along a survey line across the central Yunnan sub-block. Results suggest that the middle and upper crust of the central Yunnan sub-block is comprised of several independent high-resistivity bodies. Deep extension of some faults was revealed according to electrical structure and relocated microseismicity. The Chenghai fault extends downward along the eastern boundary of a high-resistivity body. The Yuanmou fault dips to the west and extends to the depth along the boundary between two high-resistivity bodies. The Tanglang-Yimen fault cuts through a high-resistivity body in the middle and upper crust. There is an obvious high-conductivity C1 layer in the lower crust in the eastern part of the central Yunnan sub-block, and its western border displays an obvious structural boundary in the shallow part. The eastern part of the central Yunnan sub-block moves eastward relative to the western part (bounded by the west side of a high-resistivity body R3 in the C1 west). C1 is speculated to be characterized by low rheological strength and viscosity, thus reducing the resistance to eastward movement of the eastern part. Owing to the combined action of C1 and its western boundary, the eastern materials slip eastward faster relative to R3. Due to South China Block resistance, the middle and upper crust in the eastern part is within a compressional tectonic environment, consistent with the negative dilatation rate and the presence of compressive faults in this region. The C1 ground surface has a low strain rate, indicating weak deformation in this region and rigid motion dominance. Our results suggest that under the decoupling effect of the high-conductivity layer in the lower crust, the independent rigid blocks in the middle and upper crust can also exhibit tectonic deformation characteristics of rigid extrusion.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Magnetic hyperthermia therapy (MHT) is a promising new modality to deal with solid tumors, yet the low magnetic-heat conversion efficacy, magnetic resonance imaging (MRI) artifacts, easy leakage of ...magnetic nanoparticles, and thermal resistance are the main obstacles to expand its clinical applications. Herein, a synergistic strategy based on a novel injectable magnetic and ferroptotic hydrogel is proposed to overcome these bottlenecks and boost the antitumor efficacy of MHT. The injectable hydrogel (AAGel) exhibiting a sol-gel transition upon heating is made of arachidonic acid (AA)-modified amphiphilic copolymers. Ferrimagnetic Zn0.4Fe2.6O4 nanocubes with high-efficiency hysteresis loss mechanism are synthesized and co-loaded into AAGel with RSL3, a potent ferroptotic inducer. This system maintains the temperature-responsive sol-gel transition, and provides the capacity of multiple MHT and achieves accurate heating after a single injection owing to the firm anchoring and uniform dispersion of nanocubes in the gel matrix. The high magnetic-heat conversion efficacy of nanocubes coupled with the application of echo limiting effect avoids the MRI artifacts during MHT. Besides the function of magnetic heating, Zn0.4Fe2.6O4 nanocubes combined with multiple MHT can sustain supply of redox-active iron to generate reactive oxygen species and lipid peroxides and accelerate the release of RLS3 from AAGel, thus enhancing the antitumor efficacy of ferroptosis. In turn, the reinforced ferroptosis can alleviate the MHT-triggered thermal resistance of tumors by impairment of the protective heat shock protein 70. The synergy strategy achieves the complete elimination of CT-26 tumors in mice without causing local tumor recurrence and other severe side effects.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Reactive nitrogen species (RNS) generated via the reaction of nitric oxide (NO) with reactive oxygen species (ROS) are more lethal than ROS, and thus RNS‐mediated therapy has great potential in ...cancer treatment, yet it is still largely unexploited. Herein, a novel, injectable and NO‐releasing hydrogel (NO‐Gel) composed of α‐(nitrate ester) acetic acid‐modified amphiphilic copolymers is developed. To further convert released NO to RNS, glutathione (GSH)‐sensitive CuCys nanoparticles (NPs) and β‐lapachone (Lapa) are co‐loaded into the NO‐Gel. This hydrogel system possesses a temperature‐induced sol‐gel transition and can continuously liberate Lapa, CuCys NPs, and NO in vitro for up to 3 weeks. The sustained supply of Lapa can efficiently boost hydrogen peroxide (H2O2) concentration in cancer cells, and intracellular GSH can induce the rapid release of NO and the reduction of CuCys NPs. With elevating H2O2 levels and producing highly reactive Cu(I), the Cu(I)‐catalyzed Fenton‐like reaction is dramatically enhanced, resulting in the generation of abundant hydroxyl radicals (·OH), and the subsequent cascade reactions among ·OH, H2O2, and NO cause more lethal RNS pool. After a single peritumoral injection of the hydrogel system, the cascade generation of ROS and RNS plus the substantial depletion of GSH can significantly suppress tumor growth.
An injectable thermosensitive hydrogel with inherent long‐acting NO‐releasing capacity (NO‐Gel) is developed. After loading β‐lapachone and CuCys nanoparticles into the NO‐Gel, the hydrogel system (Lapa/CuCys@NO‐Gel) can elevate intracellular reactive oxygen species and reactive nitrogen species levels and deplete glutathione through cascade reactions. A synergistic antitumor efficacy is achieved after a single peritumoral injection of the hydrogel system.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
The release and rapid diffusion of ChatGPT have caught the attention of educators worldwide. Some educators are enthusiastic about its potential to support learning. Others are concerned ...about how it might circumvent learning opportunities or contribute to misinformation. To better understand reactions about ChatGPT concerning education, we analyzed Twitter data (16,830,997 tweets from 5,541,457 users). Based on topic modeling and sentiment analysis, we provide an overview of global perceptions and reactions to ChatGPT regarding education. ChatGPT triggered a massive response on Twitter, with education being the most tweeted content topic. Topics ranged from specific (e.g., cheating) to broad (e.g., opportunities), which were discussed with mixed sentiment. We traced that authority decisions may influence public opinions. We discussed that the average reaction on Twitter (e.g., using ChatGPT to cheat in exams) differs from discussions in which education and teaching–learning researchers are likely to be more interested (e.g., ChatGPT as an intelligent learning partner). This study provides insights into people's reactions when new groundbreaking technology is released and implications for scientific and policy communication in rapidly changing circumstances.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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