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Micro/nano scratch testing is an effective technique for characterizing the mechanical properties and wear resistance of materials. In practical applications, most of the materials in equipment serve in a vibration environment. However, the scratching characteristics of materials under vibration environment have not been well investigated due to the lack of suitable testing instruments. To address this issue, in this article, we develop a vibration-assisted micro/nano scratch tester. Its working principle is introduced, followed by designing and analyzing the vibration platform. Then, the prototype is fabricated and a control system is established. After that, the key performance parameters of the tester are characterized. The results showed that the load noise is lower than 0.1 mN, and the vibration platform can generate a unidirectional vibration with the amplitude range of 0.2–11 μm and frequency range of 1–2000 Hz. To verify the feasibility of the proposed scratch tester, vibration-assisted scratch tests are performed on AL1050. It is shown that vibration during scratch testing leads to an increase in the residual scratch width and a decrease in the coefficient of friction and scratch hardness. These findings verify the effectiveness of the vibration-assisted micro/nano scratch tester and highlight the significance of considering vibration effects on the characterization of materials.

Using a deep learning method to classify a large amount of labelled remote sensing scene data produces good performance. However, it is challenging for deep learning based methods to generalise to classification tasks with limited data. Few‐shot learning allows neural networks to classify unseen categories when confronted with a handful of labelled data. Currently, episodic tasks based on meta‐learning can effectively complete few‐shot classification, and training an encoder that can conduct representation learning has become an important component of few‐shot learning. An end‐to‐end few‐shot remote sensing scene classification model based on ProtoNet and self‐supervised learning is proposed. The authors design the Pre‐prototype for a more discrete feature space and better integration with self‐supervised learning, and also propose the ProtoMixer for higher quality prototypes with a global receptive field. The authors’ method outperforms the existing state‐of‐the‐art self‐supervised based methods on three widely used benchmark datasets: UC‐Merced, NWPU‐RESISC45, and AID. Compare with previous state‐of‐the‐art performance. For the one‐shot setting, this method improves by 1.21%, 2.36%, and 0.84% in AID, UC‐Merced, and NWPU‐RESISC45, respectively. For the five‐shot setting, this method surpasses by 0.85%, 2.79%, and 0.74% in the AID, UC‐Merced, and NWPU‐RESISC45, respectively. The authors present a new framework, SRL‐ProtoNet, for remote sensing scene few‐shot classification. The self‐supervised contrastive learning is introduced to encourage inter‐class contrastive property and the Pre‐prototype and ProtoMixer is proposed for a more discrete feature space.

Marine biotoxins are metabolites produced by algae that can accumulate in shellfish or fish and enter organisms through the food chain, posing a serious threat to biological health. Therefore, accurate and rapid detection is an urgent requirement for food safety. Although various detection methods, including the mouse bioassay, liquid chromatography–mass spectrometry, and cell detection methods, and protein phosphatase inhibition assays have been developed in the past decades, the current detection methods cannot fully meet these demands. Among these methods, the outstanding immunoassay virtues of high sensitivity, reliability, and low cost are highly advantageous for marine biotoxin detection in complex samples. In this work, we review the recent 5-year progress in marine biotoxin immunodetection technologies such as optical immunoassays, electrochemical immunoassays, and piezoelectric immunoassays. With the assistance of immunoassays, the detection of food-related marine biotoxins can be implemented for ensuring public health and preventing food poisoning. In addition, the immunodetection technique platforms including lateral flow chips and microfluidic chips are also discussed. We carefully investigate the advantages and disadvantages for each immunoassay, which are compared to demonstrate the guidance for selecting appropriate immunoassays and platforms for the detection of marine biotoxins. It is expected that this review will provide insights for the further development of immunoassays and promote the rapid progress and successful translation of advanced immunoassays with food safety detection.

• Warm-rolling on the microstructure and mechanical properties of RCCAs was studied. • Warm-rolling could induce structural and compositional heterogeneity resulting in back-stress strengthening. • The warm rolled and annealed RCCAs possessed an excellent match of strength and plasticity. Compared with cold rolling, warm rolling can significantly reduce or completely eliminate microstructure damage to regulate the microstructure of the material, which is an effective method to improve the mechanical properties of the material. However, the effect of warm rolling on refractory complex concentrated alloys (RCCAs) has rarely been reported. This research examines how warm rolling influences the microstructure, texture, and mechanical properties of the Zr 45 Ti 15 Nb 30 Ta 10 RCCA. The RCCA was warm-rolled to a 75 % reduction in thickness at 650 °C (two-phase zone) and then annealed at 1000 °C for 1 h. To highlight the advantages of warm rolling, a comparison was conducted with similarly deformed and annealed cold-rolled RCCA. The warm-rolled RCCA exhibits a layered heterogeneous structure and induces the precipitation of the (Nb, Ta)-enriched bcc2 phase. The deformation texture of warm-rolled RCCA is weaker than that of cold-rolled RCCA, which is attributed to localized deformation inhomogeneity. After annealing, warm rolling resulted in a remarkable increase in the yield strength of the RCCA, i.e., from 861 MPa to 1071 MPa; meanwhile, moreover, the tensile plasticity was almost identical. Warm rolling leads to a change in plastic deformation of the RCCA from dislocation cross-slip to one dominated by the interaction of dislocations with subgrain boundaries as well as the bcc2 phase. The back tress generated by the heterogeneous structure induced by warm rolling is also effective in increasing the yield strength of the RCCA. The remarkably layered heterogeneous structure, subgrain boundaries and textures result in warm-rolled RCCA with optimal strength-ductility combination. Our results provide an effective processing approach for tailoring the microstructure and mechanical properties of RCCAs. [Display omitted] [ABSTRACT FROM AUTHOR]

At present, the existing piezoelectric stick-slip actuators have an inherent back-slip problem, which greatly limits the development and application of stick-slip actuators. In order to inhibit the regression phenomenon, a new bionic lemongrass stickslip actuator was prepared by using polymer PDMS to replicate natural biological surface. The surface microstructure of the grass was copied by PDMS, and the PDMS film was prepared. The rigid and flexible bionic friction pair was further prepared, and the flexible anisotropic PDMS stick slip actuator was developed. It was found that the anisotropic friction characteristics of the surface microstructure of the grass inhibited the anti-sliding motion, and the elastic potential energy of the PDMS film improved the output characteristics of the driver. By adjusting the input voltage to control the contact between the drive foot and the rotor, the rigid and flexible hybrid drive can be realized and the backsliding phenomenon can be suppressed. The actuator is compact, lightweight and can achieve high speed and high resolution output without preloading force, which has important application value in the field of fast and accurate positioning with load limitation.

To understand the relationship between the damage mechanism of sapphire and the anisotropic characteristic of its crystal structure, in-situscratch tests under the confocal laser scanning microscope (CLSM) were performed along different directions of C-plane sapphire wafer. The relation between in-situimages and normal/lateral forces was established. Craters in front of the contact region (CR) between the indenter and the material, and subsurface special cracks separated from CR were observed. As the scratch direction changed, these special cracks and craters initiated and propagated on the left front, front, and right front of the CR, respectively. The scratch phenomena in different scratch directions exhibited triple symmetric characteristic around the c-axis. The probability of slip/twinning activation and the theoretical stress field in front of the indenter were calculated to investigate the fracture mechanism of sapphire. Craters and those special cracks appeared in the region with the highest probability of rhombohedral twinning and basal twinning activation, respectively. According to the theoretical stress field, the material ahead of the indenter axis was separated into regions I and II. Craters in front of the CR and those special cracks separated from the CR appeared in these two regions, respectively.

High strain rates and continuous real-time data acquisition are difficult to balance in existing impact indentation techniques. Meanwhile, the inaccuracy of the testing P-hcurves limits the development of quantitative applications for dynamic testing of mechanical properties at micro region. This article develops a momentum exchange impact indentation testing method, which extends the testing range of strain rate to above 105 s−1, and at the same time avoids secondary impact. Impact indentation tests are conducted on single-crystal aluminum specimens with impact velocity from 76.9 to 176 mm/s. Based on calibrated data, the comparison of calculation methods for dynamic hardness is carried out. The dynamic elastic modulus is obtained by means of the Oliver-Pharr method, which increases from 71.9 to 89.4 GPa with increasing impact velocity. A multi-dimensional data analysis method is proposed based on the obtained experimental data to quantitatively study the damping and stiffness characteristics of materials. This testing method is particularly useful for quantitatively obtaining the micro region dynamic mechanical properties of solid materials at high strain rates.

The number of layers and ply orientations determined the service performance of carbon fiber-reinforced polymer (CFRP) materials. Under low-temperature service conditions, the unclear weakening mechanism of mechanical properties of CFRP aggravates the failure risks of aerospace structures. In present work, the unclear correlation between layers with alternating orientations and the tensile-failure mechanisms of CFRP, the low temperature-mechanical coupling micromechanical behavior, and the failure mechanism of CFRP was experimentally revealed by using a horizontal testing instrument integrated with a low-temperature loading module and real-time optical imaging function. Based on various temperatures in a range from −40 °C to room temperature (RT) and two strain rates, the gradually decreasing trends of tensile strength, Young's modulus, and elongation after fracture with decreasing temperature are obtained. Three failure modes including fiber brittle fracture, fiber pull-out, and interface debonding are proposed to reveal the low temperature-mechanical coupling failure mechanism. Low-temperature asynchronous shrinkage of carbon fiber and epoxy resin promoted the transition from fiber brittle fracture to delamination at the interface. The proposed instrument could establish the approximatively actual service conditions involving low temperature and mechanical load.

Superalloys play a critical role in aerospace applications due to their exceptional mechanical properties at high temperatures. The application of magnetic fields to regulate superalloys presents novel avenues for optimizing microstructures, controlling solidification defects, and enhancing their high-temperature properties. This paper provides a comprehensive review of research findings on the influence of magnetic fields on the microstructure and properties of superalloys. It systematically elucidates the effects of different types and intensities of magnetic fields on alloy solidification. Moreover, this paper extensively explores the effects of various types of magnetic fields on the phase composition, microstructure, and properties of superalloys, including Ni-based and Co-based alloys, as well as high-entropy alloys. The underlying mechanisms behind the impact of magnetic fields on these alloy types are thoroughly analyzed. Finally, the last section offers a brief summary of the current development status and prospects of magnetic field-regulated superalloys.

The need for very-high-cycle fatigue (VHCF) testing up to 1010cycles of aviation gas turbine engine blade materials under combined mechanical loads and complex environments has encouraged the development of VHCF testing instrumentation and technology. This article begins with a comprehensive review of the existing available techniques that enable VHCF testing. Recent advances in ultrasonic fatigue testing (UFT) techniques are highlighted, containing their new capabilities and methods for single load, multiaxial load, variable amplitude fatigue, and combined cycle fatigue. New techniques for conducting UFT in high-temperature, humid environments, and corrosive environments are summarized. These developments in mechanical loading and environmental building techniques provide the possibility of laboratory construction for real service conditions of blade materials. New techniques that can be used forin situmonitoring of VHCF damage are summarized. Key issues in the UFT field are presented, and countermeasures are collated. Finally, the existing problems and future trends in the field are briefly described.

Developing high-entropy alloys (HEAs) faces challenges owing to the inherent strength-ductility trade-off. This study systematically investigated the microstructure and mechanical properties of Al0.25FeCoNiV face-centered cubic (FCC) and body-centered cubic (BCC) duplex HEA, subjected to 70% cold rolling and annealing at various temperatures. The mechanism of the nonlinear effect of the annealing temperature on precipitation in duplex HEA was investigated. An economical and efficient thermo-mechanical processing route was developed to construct a multiscale BCC secondary phase. After 70% cold rolling and annealing at 1373 K, the yield strength (YS), ultimate tensile strength, and fracture elongation were 750 MPa, 1169 MPa, and 46.5%, respectively. This demonstrates superior strength-ductility coordination. In-situ electron backscatter diffraction (EBSD) tensile experiments were performed using a self-designed device to observe the dynamic evolution of the grain orientation and grain boundary distribution under diverse strain conditions. The influence of the multiscale BCC secondary phase on the mechanical properties was comprehensively investigated. The findings suggested that the exceptional mechanical performance was attributed to the coupled mechanism of multistage hetero-deformation-induced (HDI) strengthening and strain hardening produced by the multiscale BCC phase. Quantitative calculations revealed that the HDI strengthening (420 MPa) contributed over 50% to YS. This study lays a solid theoretical foundation for optimizing process parameters and innovating high-performance HEAs for engineering applications.

High entropy alloys exhibit excellent performance under different-temperature conditions. In order to investigate the effect of temperature on the mechanical-thermal coupling fatigue failure of classical CoCrFeMnNi high entropy alloy to accelerate the application of high entropy alloys, the uniaxial tensile and fatigue tests at temperatures ranging from RT to 500 °C were conducted, and statics simulation analysis of fatigue specimens under fatigue loading conditions was conducted. The results of the uniaxial tensile tests illustrated that the yield stress and tensile strength of the alloy decreased with increasing temperature. In contrast, the elongation after the fracture of the alloy increased with temperature. The fatigue test results revealed that the fatigue life decreased as the temperature increased. The fracture morphology of the fatigue specimens and the flank morphology and dislocation distribution near the crack nucleation zone were collected to support the investigation. Accordingly, the reasons for the high-temperature-induced decrease in fatigue crack nucleation and propagation lives were systematically investigated. The main reasons for the higher-temperature-induced decrease in crack nucleation lives were a decrease in the yield stress of the alloy, more easily triggered dislocation motion and stress homogenization. The reasons for the decrease in fatigue crack propagation lives induced by higher temperatures were the more prone occurrence of dislocation motion, a decrease in yield stress, and a decrease in the area of the crack propagation region.

Achieving timely, reversible, and long-range remote tunability over surface wettability is highly demanded across diverse fields, including nanofluidic systems, drug delivery, and heterogeneous catalysis. Herein, using molecular dynamic simulations, we show, for the first time, a theoretical design of electrowetting to achieve remotely controllable surface wettability via using a terahertz wave. The key idea driving the design is the unique terahertz collective vibration identified in the vicinal subnanoscale water layer, which is absent in bulk water, enabling efficient energy transfer from the terahertz wave to the rotational motion of the vicinal subnanoscale water layer. Consequently, a frequency-specific alternating terahertz electric field near the critical strength can significantly affect the local hydrogen-bonding network of the contact water layer on the solid surface, thereby achieving tunable surface wettability.

Global warming has caused the degradation of coral reefs around the world. While stress-tolerant corals have demonstrated the ability to acclimatize to ocean warming, it remains unclear whether they can sustain their thermal resilience when superimposed with other coastal environmental stressors. We report the combined impacts of a photosystem II (PSII) herbicide, prometryn, and ocean warming on the stress-tolerant coral Galaxea fascicularisthrough physiological and omics analyses. The results demonstrate that the heat-stress-induced inhibition of photosynthetic efficiency in G. fascicularisis exacerbated in the presence of prometryn. Transcriptomics and metabolomics analyses indicate that the prometryn exposure may overwhelm the photosystem repair mechanism in stress-tolerant corals, thereby compromising their capacity for thermal acclimation. Moreover, prometryn might amplify the adverse effects of heat stress on key energy and nutrient metabolism pathways and induce a stronger response to oxidative stress in stress-tolerant corals. The findings indicate that the presence of prometryn at environmentally relevant concentrations would render corals more susceptible to heat stress and exacerbate the breakdown of coral Symbiodiniaceae symbiosis. The present study provides valuable insights into the necessity of prioritizing PSII herbicide pollution reduction in coral reef protection efforts while mitigating the effects of climate change.

• Amorphization transformation assists in activating the dislocation nucleation. • Amorphization dominates plastic deformation under high strains. • Multi-stage deformation mode favored energy expenditure in shock waves. High-entropy alloys (HEAs) possess immense potential for structural applications due to their excellent mechanical properties. Deeply understanding underlying deformation mechanisms under extreme regimes is crucial but still limited, due to the restrictions of existing experimental techniques. In the present study, dynamic deformation behaviors in equiatomic FeNiCrCoCu HEAs were investigated in terms of various shock velocities through nonequilibrium molecular dynamics simulations. The amorphous atoms by amorphization transformation were corroborated to be conducive to dislocation nucleation and propagation. Also, the dominant plasticity pattern was confirmed to be taken over by amorphization under higher velocities, while dislocation slips merely prevailed for lower shock ones. More importantly, for a shock velocity of 1.4 km/s, multi-level deformation modes appearing in deformation, first amorphization and then a combination of amorphization and dislocation slip, was demonstrated to substantially contribute to the shock wave attenuation. These interesting findings provide important implications for the dynamic deformation behaviors and corresponding mechanisms of the FeNiCrCoCu HEA system. [Display omitted] [ABSTRACT FROM AUTHOR]

Stainless steel welding has been widely used in industrial manufacturing, and friction stir welding has been recognized to reduce production costs significantly. To fully utilize the different properties of 2507 super duplex stainless steel (SDSS) and 317L austenitic stainless steel (ASS), the mechanical and surface properties of 2507 SDSS and 317L ASS dissimilar stainless steel joints were improved using the friction stir welding (FSW) method. The influence of rotation speed on the microstructural characteristics, mechanical properties, and corrosion behavior of the weld joints was investigated by welding at a constant speed of 20 mm/min within the range of 300–600 rpm. Specifically, at 400 rpm, a welded joint with optimal performance was obtained. When the rotation speed is 400 rpm, the yield strength (YS) and ultimate tensile strength (UTS) of the welding joint are 493 and 692 MPa, respectively, and the elongation (EL) is 32 %. The tensile strength is higher than 317L ASS but lower than 2507 SDSS, the EL is lower than those of 317L ASS and 2507 SDSS, and the friction coefficient of the welded joint is 0.93, which is between 317L ASS and 2507 SDSS. Notably, the refinement of grains in the stirred zone significantly improved the corrosion resistance of the welded joint, considerably exceeding that of the 317L ASS but still lower than the 2507 SDSS. This work can provide a process reference for studying the mechanical and corrosion properties of dissimilar stainless steel FSW.

Indentation tests create complex stress–strain states in the region beneath the indentation tip. However, it is difficult to observe the indentation responses of bulk materials. Therefore, this study presents a wedge-indentation test technology that can investigate the subsurface deformation behavior during loading and unloading inside a scanning electron microscope. In situ observations based on multiple techniques, including a secondary electron detector, electron backscatter diffraction, and digital image correlation, are realized and used to investigate the texture evolution and stress–strain behavior of monocrystalline copper in the microregion beneath the indentation tip. Indentation induces kinked slip bands along the [01‾1‾] and [011‾] directions. The maximum shear strain of 0.324 occurs at the sides of the area in direct contact with the indentation tip. The lattice rotations in three dimensions are calculated and obtained quantitatively, and the geometrically necessary dislocation density beside the contact region reaches 0.70 × 1014/m2. The proposed method has considerable potential for explaining the deformation mechanisms of materials at microscale.

In this paper, a series of slit angle designs are designed to achieve the improvement of long‐term image sticking properties. The excellent image sticking of high slit angle design are attributed to the small flexo‐electric effect which is explained by using simulation and theory mode analysis, where the flexo‐electric maintains a lower level and the electric field provides a minor deformation. This novel pixel electrode design which optimizes the performance of image sticking, provides a new paradigm for the high picture quality of liquid crystal display.

The development of remote surgery hinges on comprehending the mechanical properties of the tissue at the surgical site. Understanding the mechanical behavior of the medulla oblongata tissue is instrumental for precisely determining the remote surgery implementation site. Additionally, exploring this tissue’s response under electric fields can inform the creation of electrical stimulation therapy regimens. This could potentially reduce the extent of medulla oblongata tissue damage from mechanical compression. Various types of pulsed electric fields were integrated into a custom-built indentation device for this study. Experimental findings suggested that applying pulsed electric fields amplified the shear modulus of the medulla oblongata tissue. In the electric field, the elasticity and viscosity of the tissue increased. The most significant influence was noted from the low-frequency pulsed electric field, while the burst pulsed electric field had a minimal impact. At the microstructural scale, the application of an electric field led to the concentration of myelin in areas distant from the surface layer in the medulla oblongata, and the orderly structure of proteoglycans became disordered. The alterations observed in the myelin and proteoglycans under an electric field were considered to be the fundamental causes of the changes in the mechanical behavior of the medulla oblongata tissue. Moreover, cell polarization and extracellular matrix cavitation were observed, with transmission electron microscopy results pointing to laminar separation within the myelin at the ultrastructure scale. This study thoroughly explored the impact of electric field application on the mechanical behavior and microstructure of the medulla oblongata tissue, delving into the underlying mechanisms. This investigation delved into the changes and mechanisms in the mechanical behavior and microstructure of medulla oblongata tissue under the influence of electric fields. Furthermore, this study could serve as a reference for the development of electrical stimulation regimens in the central nervous system. The acquired mechanical behavior data could provide valuable baseline information to aid in the evolution of remote surgery techniques involving the medulla oblongata tissue.

Due to the large computational and GPUs memory cost of semantic segmentation, some works focus on designing a lite weight model to achieve a good trade‐off between computational cost and accuracy. A common method is to combined CNN and vision transformer. However, these methods ignore the contextual information of multi receptive fields. And existing methods often fail to inject detailed information losses in the downsampling of multi‐scale feature. To fix these issues, we propose AG Self‐Attention, which is Enhanced Atrous Self‐Attention (EASA), and Gate Attention. AG Self‐Attention adds the contextual information of multi receptive fields into the global semantic feature. Specifically, the Enhanced Atrous Self‐Attention uses weight shared atrous convolution with different atrous rates to get the contextual information under the specific different receptive fields. Gate Attention introduces gating mechanism to inject detailed information into the global semantic feature and filter detailed information by producing “fusion” gate and “update” gate. In order to prove our insight. We conduct numerous experiments in common semantic segmentation datasets, consisting of ADE20 K, COCO‐stuff, PASCAL Context, Cityscapes, to show that our method achieves state‐of‐the‐art performance and achieve a good trade‐off between computational cost and accuracy. We propose AG Self‐Attention, Enhanced Atrous Self‐Attention, and Gate Attention to fix the ignore of multi fields context and inject detailed information.

Grade discrepancy between the primary tumor and venous tumor thrombus in renal cell carcinoma (RCC) provides pivotal prognostic value in nonmetastatic clear-cell RCC and can improve patient counseling and guide decision-making on adjuvant therapy.

• The advent of graphene allows additional TWIP and TRIP effects to coordinate deformation. • Additional coordination patterns contribute to extending the strain-hardening capacity. • One unusual twinning mode is endowed after introducing graphene. • The dynamic deformation mechanism is affected by graphene. Graphene (Gr) reinforced high-entropy alloy (HEA) matrix composites are expected as potential candidates for next-generation structural applications in light of outstanding mechanical properties. A deep comprehension of the underlying deformation mechanisms under extreme shock loading is of paramount importance, however, remains lacking due to experimentally technical limitations in existence. In the present study, by means of nonequilibrium molecular dynamics simulations, dynamic deformation behaviors and corresponding mechanisms in equiatomic FeNiCrCoCu HEA/Gr composite systems were investigated in terms of various shock velocities. The resistance to dislocation propagation imparted by Gr was corroborated to encourage the elevated local stress level by increasing the likelihood of dislocation interplays, which facilitated the onset of twins and hexagonal close-packed (HCP) martensite laths. Meanwhile, the advent of Gr was demonstrated to endow the HEA with an additional twinning pathway that induced a structural conversion from HCP to parent face-centered cubic (FCC) inside HCP martensite laths, different from the classical one that necessitated undergoing the intermediate procedure of extrinsic stacking fault (ESF) evolution. More than that, by virtue of an increase in flow stress, the transformation-induced plasticity (TRIP) effect was validated to be additionally evoked as the predominant strain accommodation mechanism at higher strains on the one hand, but which only assisted plasticity in pure systems, and on the other hand, can also act as an auxiliary regulation mode together with the twinning-induced plasticity (TWIP) effect under intermediate strains, but with enhanced contributions relative to pure systems. One may expect that TRIP and TWIP effects promoted by introducing Gr would considerably inspire a synergistic effect between strength and ductility, contributing to the exceptional shock-resistant performance of FeNiCrCoCu HEAs under extreme regimes. [Display omitted] [ABSTRACT FROM AUTHOR]

Precise spatial distribution of latent heat released during precipitation formation is crucial to enhance weather forecasting and climate prediction accuracy. This study introduces an innovative convolutional neural network heating (CNNH) algorithm. The algorithm incorporates the vertical gradient of precipitation rate and air temperature at different altitudes as key inputs. It combines additional information from adjacent vertical layers and neighboring horizontal areas. To mitigate possible misjudgments of negative heating, a punishing mechanism was introduced with a latent heating (LH)-structure loss function within the optimization framework. By employing the adaptive differential evolution (ADE) algorithm, the optimal configuration of the network structure optimizes accurate LH retrieval. To evaluate the CNNH algorithm’s efficacy, a self-consistency check using weather research and forecasting (WRF) model simulation data was conducted. Furthermore, an inter-comparison study with four other algorithms using real satellite observations was undertaken. Evaluations found that the CNNH algorithm could precisely retrieve the primary characteristics of the horizontal and vertical structure, along with the temporal evolution process and statistical information of WRF simulated LH, in eastern China in August 2017. It effectively addressed the issues of overestimation of near-surface cooling and mixing layer heating, thereby outperforming selected artificial intelligence (AI) and physics-based LH algorithms. The intercomparison study between LHCNNH with four other published LH products based on the same GPM observations reveals that CNNH got comparable performance among them. However, specific differences among these algorithms highlight considerable uncertainties in multiple LH satellite remote sensing products and underscore the necessity for further improvements in satellite LH algorithms.

When aircraft operate in critical space environments, their internal piezoelectric actuators are subjected to low temperatures and strong magnetic fields, leading to reduced output displacement, force, and accuracy. This article proposes an integrated flexible mechanism utilizing the principle of cold shrinkage, capable of maintaining pretension at low temperatures, and unlike segregated flexible mechanisms, it does not lose function due to pretension failure at extremely low temperatures. First, the working principle of piezoelectric actuators with thermomagnetic protective devices in low-temperature environments is clarified, the motion process of the piezoelectric actuators is introduced, and a simulation analysis of the cold shrinkage process of the low-temperature flexible mechanism is conducted. Then, by calculating the effects of magnetic shielding and thermal protection, the feasibility of the thermomagnetic shielding device is determined. Finally, the feasibility of maintaining a constant state under different temperature conditions is experimentally verified. This research provides guidance for the shielding and protection of piezoelectric actuators operating in harsh environmental conditions.

Refractory complex concentrated alloys (RCCAs) have drawn particular attention for their high yield strength and superior softening resistance at high temperatures. However, poor room-temperature ductility and high density remain the main challenges for their processing and applications. Here, using inherent material characteristics as the alloy-design principles, three novel single-phase body-centered cubic structured Ti3Zr1.5Nb(1−x)MoxVAl0.25(x= 0.1, 0.3, 0.5, marked as Mo0.1, Mo0.3, and Mo0.5, respectively) RCCAs with promising tensile ductility and relatively low density below 6 g cm−3were developed by tailoring the Mo concentration. The introduction of Mo elements with high shear modulus promotes lattice distortion, contributing to enhanced lattice friction stress and yield strength. The Mo0.3 and Mo0.5 alloys exhibit tensile yield strengths exceeding 1100 MPa and high fracture elongation of over 15% in the as-cast state. Labusch’s model revealed that solid-solution strengthening induced by atomic size and shear modulus mismatch contributes most significantly to yield strength. Deformation microstructure observations uncovered that the formation of the kink bands, dense-dislocation walls, and Taylor lattices are highly effective in enhancing strain-hardening capacity due to their high density of dislocation boundaries, enabling the alloys to maintain high strength while yet ensuring enough ductility. This study provides new insights into the development of strong and ductile RCCAs with single-phase structures.

The nanoindentation technique is one of the main techniques for characterizing the mechanical properties of materials at micro and nano scales, which has been extensively employed in recent years. Currently, most nanoindentation instruments adopt the quasistatic testing method. However, when components and devices work under actual conditions, most of them serve in the state of high-frequency vibration (HFV). In this study, to investigate the response of materials operating in the state of HFV to nanoindentation, a HFV nanoindentation instrument consisting of a traditional nanoindentation device and a vibration device was developed. The nanoindentation device performed the indentation process, and the vibration device provided a stable HFV. By performing the quasistatic indentation test and vibration indentation tests at different vibration amplitudes on Ti6Al4V, the effects of HFV on the load–depth curves, the microscopic characteristics of the residual indentation, and hardness values were investigated. The results showed that when increasing the vibration amplitude from 0 to $3~\mu \text{m}$ , the hardness measured by the HFV nanoindentation instrument decreased from 3.5 to 0.8 GPa, and correspondingly, the area and depth of the residual indentation increased. Besides, compared to quasistatic conditions, shear bands were prone to appear around the residual indentation at a relatively small load for nanoindentation testing under HFV conditions, which could be attributed to continuous indentation shock. This study develops a HFV nanoindentation instrument, which is of great scientific significance and application value for the evaluation of service performance and deformation mechanisms of materials serving in HFV conditions.

The performance of piezoelectric actuators can be significantly degraded when used in low-temperature conditions. To address this issue, in this article, we present a high-performance piezoelectric actuator with a relatively high coefficient of thermal expansion. This actuator is capable of dynamically adjusting the preload force with temperature. The article begins with thermodynamic simulations using Abaqus to analyze the impact of temperature on the clearance between the drive's foot and the guide. Subsequently, a dynamic model of the piezoelectric actuator is developed in Simulink to examine the influence of key parameters on drive displacement using parameter identification techniques. Finally, validating the reduction of the preload force is crucial for enhancing the actuator's performance by experiment, and low-temperature conditions have a significant 7.3-fold improvement compared to room temperature conditions with displacement. This research provides a theoretical and experimental foundation for effectively utilizing piezoelectric actuators in extremely low-temperature environments.

Observation of residual indent is widely adopted to evaluate the mechanical properties of material in temperature indentation test. However, the potential influence of the difference between the testing and observing temperatures on the material is always neglected. In this study, crystal plasticity finite element model of copper was constructed, and the processes of high-temperature indentation test and specimen temperature reduction to the observed temperature after the test were simulated. The simulations showed that the error of test hardness can reach up to 4.92% as the residual indent area decreases with temperature decreasing from 800 °C to 20 °C. The stress values of the indentation influence zone were also reduced considerably, in which the maximum stress at 20 °C was 59% of that at 800 °C. The distribution of stresses at surface and subsurface both changed substantially, while the depth of the influence zone increased by 31%. The mechanical properties of material were also found to affect the micro region deformation of residual indents during temperature recovery. Therefore, the influence of temperature variation between the testing and observing processes on residual indent should be seriously considered.

To investigate the effect of temperature on the compressive strength of CoCrFeMnNi high entropy alloy with lattice structures prepared by powder bed fusion, the mechanical properties of the lattice structures at a temperature in a range from 20 °C to 900 °C were obtained through a self-developed in-situ mechanical-thermal coupling compressive system. The real-time deformation behaviors of the lattice structures were observed by an optical-infrared dual-spectrum imaging system. The experimental results indicated that the compressive strength, structural stiffness, and energy absorption of the specimens increased with the increasing temperature ranging from 20 °C to 600 °C during the load-bearing stage, accompanied by a fracture mode from cleavage step to dimple. At an elevated temperature of 900 °C, the specimens exhibited the worst compressive strength and structural stiffness but the highest densification strain. Significantly, the temperature-dependent deformation behaviors were revealed, as the gradually increased temperature promoted the deformation failure behavior transforming from “layer by layer” to “45° shear band”. The improved plasticity at elevated temperatures enhanced the deformation capacity of lattice structures, released the local concentrated load and effectively weakened the stress concentration.

3C silicon carbide (3C-SiC) has great potential and value for innovated high-precision devices. However, the high hardness make it a daunting task to understand its deformation behavior and anisotropy effect, which impedes its processing and application. In this study, we performed molecular dynamic simulations of nanoindentation to study the deformation behavior and anisotropy effect of 3C-SiC. It is found that the elastic deformation and incipient plastic deformation are orientation-dependent, exhibiting fourfold symmetry, central symmetry and threefold symmetry while indenting on 3C-SiC (010), (110) and (111) surfaces. The dislocations nucleate and propagate due to the high shear stress induced by indentation, which in turn leads to the dissipation of shear stress in the sample. In the plastic stage, the dislocations evolve from embryonic dislocations to ribbon dislocations, and finally to prismatic dislocations. The prismatic dislocation loops are surrounded by stacking faults in {111} planes, most of which are enclosed by four stair-rod dislocations in <110> orientations. Moreover, we find that Thompson tetrahedron is suitable for understanding the anisotropy effect of ceramics with cubic diamond structure, and it is applied to investigate the formation and evolution of dislocations systematically in 3C-SiC. This research is meaningful for understanding the deformation behavior and anisotropy effect of 3C-SiC. The results may provide theoretical support for the processing and application of 3C-SiC.

High-precision cryogenic micromechanical testing apparatuses are of significant importance in investigating the micro-region mechanical properties and deformation behaviors of materials at cryogenic temperatures. In this study, a modular cryogenic indentation apparatus was designed and developed utilizing a contact-atmosphere hybrid refrigeration technique with a minimum temperature of −150 °C. The temperature of both the indenter tip and the specimen was independently controlled through a dual-channel proportional–integral–derivative (PID) feedback loop to eliminate contact thermal drift to within 0.1 nm/s. The application of cryogenic nitrogen (N2) atmosphere refrigeration eliminated additional stiffness at the indenter tip completely. The feasibility of the apparatus was demonstrated through calibrations and tests conducted on standard fused silica and single crystal nickel. Highly accurate indentation curves and micro-region mechanical properties of single crystal nickel were obtained at variable cryogenic temperatures. With decreasing temperature, both slip bands and pile-up around residual indentation imprints were weakened. Notably, at −150 °C, the slip bands disappeared, and the phenomenon of pile-up was replaced by sink-in. This developed cryogenic indentation apparatus will be a powerful tool to reveal the effect of cryogenic temperatures on the evolution mechanisms of materials’ micro-region mechanical properties.

Two types of triazine-based covalent organic polymers were successfully constructed through a one-pot and catalyst-free polycondensation approach. More specifically, two kinds of aromatic aldehyde containing different hydroxyl content named terephthalaldehyde and 2, 4, 6-trihydroxyisophthalaldehyde were selected and the derived polymers (denoted as POPs-1 and POPs-2) with large Brunauer-Emmett-Teller (BET) surface areas (> 360 m2/g), high total pore volume (> 0.47 m3/g), good stability and different heteroatoms (such as N and O) contents were prepared. Interestingly, POPs-1 featuring high BET surface area and N content (up to 34.83 %) exhibited excellent iodine vapor uptake of 441 wt% at 348 K/1.0 bar, POPs-2 with high O content (up to 25.83 %) showed better CO2adsorption capacity (91.8 mg/g) at 273 K/1.0 bar and higher isosteric heat of adsorption (up to 85.0 kJ/mol) than that of POPs-1. This value of the isosteric heat is the highest value reported to date for porous organic polymers. This excellent adsorption performance was resulted either from the large BET surface area or high heteroatoms (N and O) contents of the porous adsorbents. The study offer an alternative route to develop high-performance porous adsorbents to capture carbon dioxide and iodine.

• Tripodal piezoelectric device with 600 °C heating function to realize tensile-bending fatigue test. • A modified Coffin-Manson equation based on tensile-bending-thermal combined loading was proposed. • Prediction method of mechanical thermal coupling multiaxial fatigue life with high-accuracy. With regard to the structures subjected to severe mechanical-thermal coupling fatigue conditions, the consistency between service conditions and loading conditions was the prerequisite for the fatigue properties test and fatigue life prediction. A miniature piezoelectric-driven instrument integrating with a tripodal piezoelectric actuator and envelope-type heating function was developed to investigate the mechanical-thermal coupling fatigue properties and obtain the fatigue life of materials under approximate service conditions. A physical model was described to quantitatively calculate the alternating deformation under the mechanical-thermal coupling tensile-bending combined condition. Accordingly, a fatigue life prediction method based on the Coffin-Manson equation under tensile-bending combined loading was proposed to estimate the mechanical-thermal coupling fatigue life in terms of the total coupling deformation and plastic strain amplitude. The feasibility of the proposed instrument was verified through the analysis of displacement responses of high entropy alloy specimens under the thermal-mechanical coupling tensile-bending combined condition at temperatures ranging from RT to 600 °C. The comparison between fatigue lives directly measured through thermal-mechanical coupling experiments and theoretically predicted fatigue lives indicated the availability of the modified Coffin-Manson equation. [ABSTRACT FROM AUTHOR]

The performance degradation at low temperatures and frequent safety accidents have aggravated security risks and inhibited the long-term service of lithium-ion batteries (LIBs). As a key component of LIBs, the separator has a great impact on the performance and safety of the battery. In this study, tensile tests of two commercial polyolefin separators (Celgard 2325 and Celgard PE) are performed under low-temperature and immersion conditions. Four representative temperature points and dimethyl carbonate [(DMC), the common solvent in electrolytes] are selected to investigate the coupling effect on the mechanical properties of the separators. The results show that both the separators have anisotropy, but the performance of Celgard 2325 varies more significantly than that of Celgard PE along different directions. Additionally, it is found that with a decrease in the temperature, the tensile strength of the two separators increases, while the elongation decreases. Electrolyte immersion induces a softening tendency in Celgard 2325. Due to the special effect of the residual electrolyte on polyethylene fibers, Celgard PE shows the opposite result. Furthermore, the effect of low temperature is revealed by the analysis of the crystallinity and molecular structure, which can be obtained by X-ray diffraction and Raman spectroscopy, respectively. In addition, the contact angle is measured to describe the wettability variation related to low temperature. The present work provides a theoretical basis and experimental data for the application and development of separators.

Recently, with the development of deep‐learning, the performance of multiple object tracking (MOT) algorithm based on deep neural networks has been greatly improved. However, it is still a difficult problem to successfully solve the tracking misalignment caused by occlusion and complex tracking scenes. Most of the work focusses on designing a sophisticated network, only little work focusses on data association. Actually, data association is very helpful in MOT. In this study, data association in tracking is taken as the main research task, and the authors introduce quadratic graph matching into MOT. Considering the objects in each frame as a graph, we can model the data association between two frames as a quadratic graph matching problem. And then it is transformed into a convex quadratic optimisation problem. Introducing high‐order structure features into the matching function effectively solves some tracking problems. The data association is designed into the tracking model as an overall solution. Experiments show that the proposed data association algorithm performs favourably against several state‐of‐the‐art data association methods and can be used in any tracking‐by‐detection method. Our code is publicly available from https://github.com/gjy0514/G_Model. This paper mainly introduces a data association method based on quadratic graph matching. We construct the objects in each frame as a graph. In addition to using vertex information, we also consider using edge information. That is, using structural information to make data association more stable and accurate. We conduct a series of experiments on MOT15, MOT17 and KITTI datasets. Compared with the existing data association methods with excellent performance, the results prove the superiority of our method.

Overload failure under coupling conditions of elevated temperature and combined tension-bending (CTB) is one of the typical failure modes of aero-engine low-pressure compressor blade materials, which is commonly occurring in fighter engines performing low-altitude high-speed penetration missions. In this study, the elasto-plastic deformation behavior and fracture mechanism of Ti–6Al–4V titanium alloy under coupling conditions of elevated temperature and CTB were investigated by experiments and finite element analysis (FEA). CTB tests were conducted on Ti–6Al–4V alloy in the pre-tension ratio range of 0.60–0.90 and in the temperature range of 298 K–573 K. The results show that the maximum bending load, effective bending modulus, and total energy dissipated for the Ti–6Al–4V alloy at room temperature increase with the increase of the pre-tension ratio. The maximum bending load and the energy dissipated are significantly higher at elevated temperatures compared to that of room temperature, due to the elevated temperature induced deformation mode change from bending-dominated to tensile-dominated. The FEA results are in good agreement with the experimental results. SEM fractography indicated that the Ti–6Al–4V alloy fracture at elevated temperature showed only equiaxed dimples, which exhibited a tensile fracture mode. This study is valuable for the in-depth understanding of the deformation behavior and fracture mechanism of blade materials under elevated temperature and complex loads.

• High density of defect sinks and high thermal stability in nano metallic materials. • Ni-SWCNT/Ni-AC interfaces as fast transportation channels for irradiation defects. • AC layer applies compressive stress, inhibits the GB migration and defect generation. • Flexible hybrid applicable onto arbitrary surfaces as irradiation shielding material. Nanostructured materials with abundant defect sinks show good radiation tolerance due to their efficient absorption of irradiation-induced interstitials and vacancies. However, the poor thermal stability and limited size of such nanomaterials severely limit their practical applications. Herein, we report a novel flexible free-standing network-structured hybrid consisting of amorphous carbon encapsulated nickel nanocrystals anchored on a single-wall carbon nanotube scaffold with excellent radiation tolerance up to 5 dpa at 673 K and exceptional thermal stability up to 1073 K. The nano-scale Ni-SWCNT network with abundant Ni-SWCNT interfaces and grain boundaries provides effective sinks and fast transportation channels for defects, which effectively absorb irradiation-induced defects and improved the irradiation tolerance. Furthermore, the formation of a low-energy Ni-C interface and surface thermal grooves significantly reduces the system free energy and increased thermal stability. The amorphous carbon layer produces an external compressive radial stress that inhibits Ni grain boundaries from migrating, which greatly improves the thermal stability of the hybrid by pinning GBs at grooves between grains and facilitates the annihilation of irradiation-induced defects at the sinks. This work provides a new strategy to improve the thermal stability and radiation tolerance of nano-materials used in an irradiation environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: External electric fields can regulate the neural network and change the excitability of the in-vivocerebral cortex. Here, to prove the effect of alternating electric fields on the synaptic plasticity of ex-vivotissues, the regular changes in the synaptic structure under alternating electric fields were studied. Methods: This study applied alternating electric fields with a peak voltage of 20 V and frequencies of 5, 20, 50, and 80 Hz to the porcine cerebral cortex. Relying on transmission electron microscopy (TEM), the ultrastructure of synapses was observed, and the curvature radius of post-synaptic density (PSD) and the synaptic gap distance was quantified. Results: The results indicated that under alternating electric fields, the average synaptic curvature of the PSD decreased by 30–59% with increasing frequency, and the average synaptic gap distance became narrower. Conclusion: In ex-vivobrain tissue, synaptic plasticity can be regulated by alternating electric fields of different frequencies. This study can provide reference data for the storage and regulation of ex-vivoorgans, as well as comparable data for in-vivostudies.

Federated learning has become an emerging hot research field in industry because of its ability to perform large-scale distributed learning while preserving data privacy. However, recent studies have shown that in the actual use of federated learning, there are device heterogeneity and data not identically and independently distributed (Non-IID) characteristics between client nodes, which will affect the effect of federated learning. In this work, we propose resilient reinforcement federated learning (R$^{2}$Fed), a R$^{2}$Fed method, which applies reinforcement learning to federated learning and uses reinforcement learning for weighted fusion of client models instead of average fusion. We conduct experiments on object detection, object classification, and sentiment classification tasks in the context of Non-IID and heterogeneity, and the experimental results show that the R$^{2}$Fed method outperforms traditional federated learning, increasing the average accuracy by 4.7%. Experiments also demonstrate that R$^{2}$Fed is resilient to federation attacks.

Nanotwinned high entropy alloys (HEA) offer promising applications in engineering due to their remarkable mechanical properties. However, the influence of twin boundaries (TB) on the deformation behavior and surface/subsurface damage of nanotwinned HEAs during friction and nanocutting processes is still unclear. To address this issue, molecular dynamics simulations were conducted to investigate the TB effect on the nanoscratching response of nanotwinned CoCrCuFeNi HEA (nt-HEA). The results show that the TB leads to lateral atomic movement in the upper twinning layer during nanoindentation, which hinders the slip of dislocations to the lower twinning layer. During nanoscratching, downward TB migration and upward TB migration are observed due to the lateral atomic movement in TB or in upper atomic layer of TB at different positions of the sample. In addition, the propagation of dislocations in the lower twinning layer is observed, leading to the release of shear stress in the upper twinning layer. The nt-HEA also exhibits strong anisotropy during nanoscratching, with more sessile dislocations generated for backward (along [1¯1¯2]orientation) scratching. The sessile dislocations contribute to the strengthening and dislocation hardening in the subsurface of nt-HEA. The stacking faults in the lower twinning layer are more stable for backward scratching due to the formation of stair-rod dislocations. These findings provide new insights into the TB effects on the deformation behavior of CoCrCuFeNi HEA during nanoscratching, and are of great significance for the industrial application of nanotwinned HEA.

Although surgery is the primary method to treat malignant melanoma, it has drawbacks such as residual tumor that could trigger cancer recurrence and wound infections that are especially difficult to heal in diabetics. In this research, we have constructed anti-cancer peptides/polyvinyl alcohol (PVA) double-network (DN) hydrogels for the treatment of melanoma. The maximum stress of the DN hydrogels is found to be larger than 2 MPa, which endows the DN hydrogels with ideal mechanical performance for therapeutic wound dressing. The peptides naphthalene-FIIIKKK (IK1) and phloretic acid-FIIIKKK (IK3) that were previously developed as effective antibacterial peptides, as well as the peptide/PVA DN hydrogels, are found to have good anti-cancer efficacy and target mouse melanoma cells B16-F10 while being nontoxic to normal cells. Further studies have revealed that IK1 and IK3 damage the tumor cell membrane and mitochondrial membrane and eventually trigger apoptosis. In the mouse melanoma model and the diabetic bacterial infection model, the DN hydrogels exhibit great anti-tumor, anti-bacterial, and wound healing promotion abilities in vivo. Because of their excellent mechanical properties, the DN hydrogels are promising soft materials for directly treating malignant melanomas as well as for preventing recurrence and bacterial infection after melanoma surgery that promote wound healing.

The elucidation of the mechanisms underlying articular cartilage lesions poses a formidable challenge in the field of cartilage repair. Despite significant strides in cartilage mechanics research, the region-dependent creep properties of articular cartilage remain elusive. In this study, we employ depth-sensing indentation tests to experimentally determine the creep properties of four distinct regions of articular cartilage, thereby unveiling a region-dependent full map of creep parameters. The measured creep displacement-time response curves indicate that the creep properties of the articular cartilage exhibit a clear regional correlation. Accordingly, the full regional creep map of articular cartilage is experimentally constructed for the first time. The correlation between the microstructures and the creep properties of cartilage in different regions is revealed. A three-parameter model is established to describe the creep velocity–displacement response of cartilage. Raman spectra reveal that the proteoglycan content is positively correlated with creep properties. The Raman shift directly indicates diverse residual stresses in different microregions. The obtained data facilitate a deep understanding of the potential creep dependent damage mechanism of cartilage and the further development of artificial cartilage materials.

Herein, two types of Fc-based hypercrosslinked polymers (HHCP and DHCP) with high BET surface area (953.9 and 1062.7 m2 g−1) were prepared by direct one-step phenolic polycondensation aiming at high uptake capacity towards H2. As expected, the hydrogen uptake values of HHCP and DHCP were notably higher than those of porous polymers with a higher surface area under the same conditions. The maximum H2uptake of HCPs at 77 K/1.0 bar are determined to be 2.51 wt % for HHCP and 2.74 wt % for DHCP, respectively. Despite the pore structure playing a determinant role in hydrogen adsorption, the adsorption sites in the polymer framework can be another essential factor to influence the hydrogen adsorption capacity. The interactions between the Fc building block and H2are revealed by DFT calculation to fully illustrate the role of Fc in H2adsorption. The results indicate that both iron atoms and benzene rings in Fc-based HCPs contribute to the adsorption of hydrogen. Moreover, it is interesting to find that the most stable adsorption site around the Fc building unit is the position directly above the Cp ring. The results in this work may more reasonably explain the phenomenon that the introduction of Fc units could enhance the adsorption of H2in many studies, which also provides possible insights into the application of metallocene compounds in H2adsorption.

Magnesium alloys exhibit poor formability at room temperature owing to their hexagonal close-packed crystal structure. In this study, a multi-step preform and electropulsing treatment method was applied to the plastic deformation of AZ31B magnesium alloy to improve its cumulative ductility. The mechanical properties, microstructure, and dislocation evolution were investigated using various parameters. The cumulative elongation of all specimens increased significantly, with the maximum approximately twofold higher for the initial specimens. Although the yield strength decreased after the first step, it increased with the following steps. After electropulsing treatment, the specimens were recrystallized and the dislocations were annihilated. The deformed microstructure caused by preform recovered and the recovery degree was associated with the preform and electropulsing treatment parameters. Therefore, the preform and electropulsing treatment method is effective to enhance the ductility of AZ31B magnesium alloy at room temperature, and a set of appropriate pulse current parameters can achieve satisfactory strength and elongation results. Moreover, the effect of the pulse current on the dislocation mobility and climb mainly accounts for the beneficial restoration during the preform and electropulsing treatment process.

Rice is the primary staple food for more than 50% of the world’s population. Narrowing the gap between the maximum potential food crop yield and actual yield is critical for improving the current yield, resource use efficiency, and global food security. Here, we examined the fertilizer use efficiency (FUE), radiation use efficiency (RUE), and temperature production efficiency (TPE) of four management treatments (super high yield [SH], high yield and high efficiency [HH], farmer level [FP], and basic production level [CK]). SH and HH treatments significantly reduced the yield gap by 22.4 and 9.5%, respectively. The large yield gap between HH and FP was mainly attributed to high specific leaf weight at the jointing stage (7.5–7.7 mg·cm−2), and the high leaf area maintained during tillering–jointing stages (35.4–37.6 m2·m−2·per day). Compared with FP, HH increased the specific leaf weight in the heading stage (8.2–8.4 mg·cm−2), relative crop growth rate, net assimilation rate (NAR), and mean leaf area index (> 2.6). Moreover, compared with FP, HH significantly increased partial factor productivity (PFP) of nitrogen, FUE, TPE, and RUE owing to greater yield and NAR after the full heading stage. Although the HH yield was 93.32% that of SH, HH increased PFP of fertilizer (12.5%), fertilizer nitrogen (9.07%), and fertilizer K2O (36.34%), and required 26% less fertilizer than SH. The findings of this study could facilitate high-efficiency rice production and bridging of yield gaps.

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The prenylated flavonoid icaritin (ICT, 1), a new drug for treating advanced hepatocellular carcinoma (HCC), was selected as a template to develop more potent inhibitors. An initial semisynthetic modification of ICT was performed to obtain a structure–activity relationship (SAR), which indicated that the cytotoxicity is enhanced by OH-3 rhamnosylation and that OH-7 is an important modification site. Based on the results of the SAR study, 46 N-containing ICT derivatives were synthesized and evaluated as the anti-HCC inhibitors. The results showed that most of the derivatives produced inhibited three HCC cell lines used (Hep3B, HepG2 and SMMC-7721). The modification strategy was validated by 3D-QSAR, which provided information for the further design and optimization of ICT. The most potent compound, 11c, exhibited IC50values of 7.6 and 3.1 μM against HepG2 and SMMC-7721 cells, respectively, which were more potent than those of ICT and sorafenib, respectively. Further mechanistic studies indicated that 11ccaused arrest at the G0/G1phase in the cell cycle and induced cell apoptosis in HepG2 and SMMC-7721 cells.