Showing papers by "Changsong Zhou published in 2023"
TL;DR: In this paper , a sandwich-structured 0.5TiO3-based (BNT) piezoceramics is engineered for mitigating the conflict between d33, Td and Ttc, which severely hinders their industrial application in the field of elevated temperatures.
Abstract: An imminent challenge of lead-free Bi0.5Na0.5TiO3-based (BNT) piezoceramics is that the giant piezoelectric constant (d33) caused by the morphotropic phase boundary is incompatible with a high depolarization temperature (Td) and ultralow temperature coefficient (Ttc) of the real-time d33, which severely hinders their industrial application in the field of elevated temperatures. Herein, a sandwich-structured 0.94Bi0.5Na0.5TiO3-0.06BaTiO3/0.89Bi0.5Na0.5TiO3-0.11BaTiO3/0.94Bi0.5Na0.5TiO3-0.06BaTiO3 (SWS-6/11/6BT-y, where y refers to the weight fraction of the BNT-11BT solid solution) ceramic composite is engineered for mitigating the conflict between d33, Td and Ttc. Following this strategy, ultrahigh Td near the Curie point (225 °C, close to that of the BNT-11BT layer) and relatively large d33 (130 pC/N, close to that of the BNT-6BT layer) are simultaneously realized in a SWS-6/11/6BT-40%-Q ceramic composite. More importantly, the ultralow Ttc (0.07%) of real-time d33 is also achieved in this work. The structural heterogeneity yields the high piezoresponse, and the built-in field resulting from layer-type ceramic composites provides the driving force to promote the diffused ferroelectric-relaxor phase transition and the resultant ferroelectric order with high Td. The above synergistic contributions realize the remission of the d33-Td-Ttc conflict in a sandwich-structural SWS-6/11/6BT-40% ceramic composite. Thus, our work provided a path for designing the BNT-based piezoceramics with potential for industrial applications.
2 citations
TL;DR: In this article , the evolution of wave patterns utilizing data from high spatiotemporal resolution optical voltage imaging of mice transitioning from barbiturate-induced anesthesia to wakefulness (N = 5) and awake mice (n = 4).
Abstract: Rich spatiotemporal dynamics of cortical activity, including complex and diverse wave patterns, have been identified during unconscious and conscious brain states. Yet, how these activity patterns emerge across different levels of wakefulness remain unclear. Here we study the evolution of wave patterns utilizing data from high spatiotemporal resolution optical voltage imaging of mice transitioning from barbiturate-induced anesthesia to wakefulness (N = 5) and awake mice (N = 4). We find that, as the brain transitions into wakefulness, there is a reduction in hemisphere-scale voltage waves, and an increase in local wave events and complexity. A neural mass model recapitulates the essential cellular-level features and shows how the dynamical competition between global and local spatiotemporal patterns and long-range connections can explain the experimental observations. These mechanisms possibly endow the awake cortex with enhanced integrative processing capabilities.
2 citations
TL;DR: In this article , a heterogeneous Fenton-like reaction for gaseous toluene removal was enhanced by loading an amount of iron elements onto the hypercrosslinked polymeric resin (LXQ-10) as a novel catalyst.
2 citations
TL;DR: In this article , the effect of high-field polarization on the enhanced photovoltaic performance of a ferroelectric ceramic, 0.98KNbO3−0.02SrCo0.5Hf0.4−δ (KNSCH2), was explored in terms of bandgap variation.
Abstract: Polarization is one of the unique properties of ferroelectric materials; yet the polarization mechanism for enhancing ferroelectric photovoltaic performance is rarely been investigated, particularly in terms of bandgap variation. In this work, the effect of high-field polarization on the enhanced photovoltaic performance of a ferroelectric ceramic, 0.98KNbO3–0.02SrCo0.5Hf0.5O3−δ (KNSCH2), was explored in terms of bandgap variation. The bandgap of the KNSCH2 sample shrank after polarization because of the increase in potential energy band overlap and the upward shift of the valence band due to increased oxygen-vacancy defects. The polarization optimized the energy band structure of KNSCH2, promoting the separation and transport of photoinduced carriers and thus further enhancing its photovoltaic performance. The KNSCH2 sample shows a twofold enhancement in Jsc after 60 kV/cm polarization. The degree of the lattice distortion of KNSNH2 increased following polarization, causing a minute increase in its cell asymmetry. The reasons for the bandgap narrowing and the creation of sub-bandgaps in the KNSCH samples were also investigated. This work opened new doors to understanding the mechanisms underlying the polarization-enhanced photovoltaic performance of ferroelectric materials.
1 citations
1 citations
TL;DR: In this article , an iron-based porous resins were successfully synthesized by loading iron element onto hyper crosslinked polymeric resin (LXQ-10) through a static impregnation method.
1 citations
29 Jun 2023
TL;DR: In this article , the authors developed a comprehensive computational and analytic framework to establish that the transient state equivalence holds when the average generation time matches and average removal time, resulting in minimal Markovian estimation errors in the basic reproduction number, epidemic forecasting, and evaluation of control strategy.
Abstract: The initial transient phase of an emerging epidemic is of critical importance for data-driven model building, model-based prediction of the epidemic trend, and articulation of control/prevention strategies. In principle, quantitative models for real-world epidemics need to be memory-dependent or non-Markovian, but this presents difficulties for data collection, parameter estimation, computation and analyses. In contrast, the difficulties do not arise in the traditional Markovian models. To uncover the conditions under which Markovian and non-Markovian models are equivalent for transient epidemic dynamics is outstanding and of significant current interest. We develop a comprehensive computational and analytic framework to establish that the transient-state equivalence holds when the average generation time matches and average removal time, resulting in minimal Markovian estimation errors in the basic reproduction number, epidemic forecasting, and evaluation of control strategy. Strikingly, the errors depend on the generation-to-removal time ratio but not on the specific values and distributions of these times, and this universality will further facilitate estimation rectification. Overall, our study provides a general criterion for modeling memory-dependent processes using the Markovian frameworks.
TL;DR: In this article , the effect of increased defects induced by high-field polarization on bandgap evolution and photovoltaic properties was investigated, and it was shown that the defect concentration in KNSNH2 is the cause of the variation in bandgap structure.
TL;DR: In this article , the effects of synaptic impairment on neural activities associated with memory recall, memory rescue, and learning a new memory, in an integrate-and-fire neuronal network were studied.
TL;DR: In this paper , the multiscale entropy (MSE) of resting-state EEG signals among a sample of young healthy adults (N = 260) as an indicator of brain signal complexity was investigated.
Abstract: It is well established that the e4 allele of the APOE gene is associated with impaired brain functionality and cognitive decline in humans at elder age. However, it is controversial whether and how the APOE e4 allele is associated with superior brain function among young healthy individuals, thus indicates a case of antagonistic pleiotropy of APOE e4 allele. Signal complexity is a critical aspect of brain activity that has been associated with brain function. In this study, the multiscale entropy (MSE) of resting‐state EEG signals among a sample of young healthy adults (N = 260) as an indicator of brain signal complexity was investigated. It was of interest whether MSE differs across APOE genotype groups while age and education level were controlled for and whether the APOE genotype effect on MSE interacts with MSE time scale, as well as EEG recording condition. Results of linear mixed models indicate overall larger MSE in APOE e4 carriers. This genotype‐dependent difference is larger at high as compared with low time scales. The interaction effect between APOE genotype and recording condition indicates increased between‐state MSE change in young healthy APOE e4 carriers as compared with non‐carriers. Because higher complexity is commonly taken to be associated with better cognitive functioning, the present results complement previous findings and therefore point to a pleiotropic spectrum of the APOE gene polymorphism.
TL;DR: In this paper , the authors explored the plasticity of intersubject similarity in functional connectivity induced by long-term abacus-based mental calculation (AMC) training and found robust training effect of enhanced ISFC, after accounting for the factor of development.
Abstract: The individual difference of intrinsic functional connectivity is increasingly acknowledged to be biologically informative and behaviorally relevant. However, such valuable information is still discounted as a stochastic variation in previous studies of cognitive training. Here, we explored the plasticity of intersubject similarity in functional connectivity (ISFC), induced by long-term abacus-based mental calculation (AMC) training. Using a longitudinal dataset (AMC: n = 40, 5-year training; Control: n = 43), we found robust training effect of enhanced ISFC, after accounting for the factor of development. Notably, the enhancement focused on selective subsets of FCs, or the "critical FCs," which predominantly impacted the default-mode and visual networks. Using a cross-sectional dataset with a larger sample (AMC: n = 93, 1/3/5-year training; Control: n = 110), we observed that the "critical FCs" and its intersubject similarity could predict mental calculation ability and its intersubject similarity, respectively, in the AMC group. However, such predictions cannot be generalized to the control group, suggesting that long-term training may be a prerequisite for establishing such brain-behavior relationships. Jointly, our findings implicated that the enhanced ISFC with profound impact on the default-mode network could be a plastic change that is associated with behavioral gains of training.
TL;DR: In this article , the defect-induced bandgap intermediate state is derived from the 3D split state of Ni and plays a dominant role in lowering the bandgap of Semiconducting (1−x) KNbO3−xBaNi 0.5Hf0.5O3 −δ (KNBNH, x = 2, 4, 6, 8%) ferroelectric ceramics with enhanced photovoltaic performance.
Abstract: The inversion asymmetry of polar crystals enables ferroelectric ceramics to possess unique physical properties, among which the anomalous photovoltaic effect drives their potential application in photovoltaic conversion. Semiconducting (1−x) KNbO3−xBaNi0.5Hf0.5O3−δ (KNBNH, x = 2, 4, 6, 8%) ferroelectric ceramics with enhanced photovoltaic performance were prepared by utilizing conventional solid-state sintering strategies. In these ceramics, the defect-induced bandgap intermediate state is derived from the 3d split state of Ni and plays a dominant role in lowering the bandgap of KN. The defective bandgap state induced by Ni in KNBNH promotes its absorption of light and the separation of photogenerated carriers, thus enhancing its photovoltaic response. The KNBNH6 shows a maximum value of 138.7 nA/cm2 for short-circuit photocurrent density (Jsc) among these ceramics, which is further enhanced to 702.9 nA/cm2 after 30 kV/cm polarization. Structural investigations after polarization indicate that polarization induced lattice distortion in KNBNH6, leading to an increase in the polarity of its cells. This work provides an understanding of defect-induced bandgap states and high-field polarization to enhance ferroelectric photovoltaic properties. This article is protected by copyright. All rights reserved
TL;DR: In this paper , a two-dimensional hierarchical FeSe2/g-C3N4 nano-heterojunction was purposefully synthesized via a modified initial wetting impregnation followed by hydrothermal selenization method and further demonstrated to be an efficient trap for Hg0 immobilization.
TL;DR: In this paper , an MPB with coexisting rhombohedral (R) and tetragonal (T) phases was used for lead-free piezoelectric ceramics.
TL;DR: In this article , the authors implemented the slim P-E loops by Gd/Ta substitution at A/B sites, which provided a superior energy storage performance with a Wrec of 6.99 J/cm3 under 400 kV/cm.
TL;DR: In this article , a high d33 of 186 pC/N and a Td of 133°C are achieved simultaneously in unmodified 0.93(Bi0.5Na0.3)-0.07BaTiO3 (BNT-7BT) ceramics only via optimizing sintering temperature.
TL;DR: In this paper , an efficient multifunctional anti-corrosive interface modification strategy based on 2,2′−(1,3]-phenylene)−bis[5−(4−tert−butylphenyl)−1, 3, 4−oxadiazole] (OXD•7) is proposed to overcome the cathode interface issues.
Abstract: The interface stability and non‐radiative recombination loss of the cathode interface greatly limit the stability and performance of inverted perovskite solar cells (PSCs). Here, an efficient multifunctional anti‐corrosive interface modification strategy based on 2,2′‐(1,3‐phenylene)‐bis[5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole] (OXD‐7) is proposed to overcome the cathode interface issues. OXD‐7 molecules chemically coordinate to the Ag electrode and form a chemically stable complex film of OXD7‐Ag, which suppresses halide ion migration and thus enhances the corrosion resistance of the electrode as well. In addition, the trap density of perovskite film, PCBM/Ag interfaces contact, the built‐in potential, moisture resistance, as well as the unfavorable interface exciton dissociation elimination of the devices, are also improved with the OXD‐7 arrangement upon PCBM film, which correspondingly enhances the device performance and stability. Bidirectional halide ion migration and the ITO corrosion are observed, which is also suppressed by the OXD‐7 modification. The high power conversion efficiency (PCE) of 21.84% and the high fill factor (≈84.63%) is obtained via this strategy, which is one of the highest PCEs and FFs based on solution‐process MAPbI3/PCBM heterojunctions. The PCE can maintain ≈80% of its initial value after 1080 h at 85 °C with OXD‐7 modification.