Constructing a supercapacitor-memristor through non-linear ion transport in MOF nanochannels.

The coexistence and coupling of capacitive and memristive effects have been an important subject of scientific interest. While the capacitive effect in memristors has been extensively studied, the reciprocal scenario of the memristive effect in capacitors remains unexplored. In this study, we introduce a supercapacitor-memristor (CAPistor) concept, which is constructed by leveraging non-linear ion transport within the pores of a metal-organic framework zeolitic-imidazolate framework (ZIF-7). Within the nanochannels of the ZIF-7 electrode in an aqueous pseudocapacitor, the anionic species (OH-) of the electrolyte can be enriched and dissipated in different voltage regimes. This difference leads to a hysteresis effect in ion conductivity, constituting a memristive behavior in the pseudocapacitor. Thus, the pseudocapacitor-converted CAPistor seamlessly integrates the programmable resistance and memory functions of an ionic memristor into a supercapacitor, demonstrating enormous potential to extend the traditional energy storage applications of supercapacitors into emerging fields, including biomimetic nanofluidic ionics and neuromorphic computing.

A new method to measure the mechanical properties of rotary endodontic Ni-Ti files: Measurement of 6-axis force/torque and automatic root canal preparation.

The purpose of this study was to develop a new instrument to measure the mechanical properties of rotary endodontic Ni-Ti files (ProTaper Gold F2, ProTaper Ultimate F2, and HyFlex EDM Onefile), and to evaluate the overall utility of the device. The instrument was capable of analyzing the 6-axis force/torque generated by the files during cyclic dynamic movement in a metal curved artificial root canal, and doing automatic cyclic dynamic filing in a resin root canal with a preset vertical force limit by adopting a negative feedback mechanism. By analyzing the 6-axis force/torque, we were able to estimate the position and contact points of the files in the curved root canal. ProTaper Gold showed the highest force/torque in all directions. HyFlex EDM had the highest hysteresis ratio, centering ratio value and NCF (number of cycles to fatigue fracture), while the lowest vertical force.

Insight into the structure-activity relationship of thermal hysteresis activity of cod collagen peptides through peptidomics and bioinformatics approaches.

To elucidate the correlation between variations in thermal hysteresis activity (THA) and the physicochemical properties and structure, antifreeze peptides (AFPs) of isolated fractions (CCP-1 and CCP-2) were characterized on based peptidomics and bioinformatics. The results revealed a positive correlation between the THA of cod collagen antifreeze peptide (CCAFP) and peptide chain length, isoelectric point, and hydrophobic amino acid content. Notably, the THA of CCP-1, which has higher alkaline amino acid content, was 2.60 °C at a concentration of 10 mg/mL, significantly higher than CCP (1.90 °C) and CCP-2 (2.27 °C). Glycine, proline, and valine were the vital amino acids to the formation of hydrogen bonds. Conversely, aspartic and glutamic acids at terminal regions of AFPs tended to introduce kinks in their structures. This distortion reduced binding sites for ice crystals, thereby decreasing their THA, providing a theory for understanding the physicochemical properties and structure of AFPs that influence their THA.

Hysteresis operator-based adaptive Kalman feedforward control for the scanning motion of hybrid reluctance actuators.

The hybrid reluctance actuator (HRA) has achieved widespread application in scanning motion tasks. However, the nonlinear perturbations arising from position-dependent stiffness fluctuations, hysteresis, eddy, and flux leakage can significantly affect the control performance. To enhance the control performance of HRA-based systems in scanning motion, this paper introduces an adaptive feedforward method, known as the Chua operator-based Kalman feedforward compensator (COKFC), which aims to mitigate these nonlinear perturbations, with a PID controller serving as the central control element. In the COKFC approach, a Chua operator is employed to effectively capture the inverse hysteresis behavior. A Chua-based time-varying feedforward compensation model is then formulated to represent the inversion of the nonlinear perturbations inherent in the HRA. An improved Kalman filter is utilized for the real-time adaptation of the time-varying parameters within the feedforward compensation model. The design procedure for this control strategy is presented. Experimental evaluations are conducted on an HRA-based stage (HRA-BS), and comparisons are made between the proposed method and several advanced control methods. The experimental results demonstrate that the proposed COKFC method exhibits superior control performance for the scanning motion of the HRA-BS, highlighting its effectiveness in practical applications.

Electronic Confinement-Restrained Mn Na · ${\mathrm{Mn}}_{{\mathrm{Na}}}

Sodium (Na) super-ionic conductor structured Na3MnTi(PO4)3 (NMTP) cathodes have garnered interest owing to their cost-effectiveness and high operating voltages. However, the voltage hysteresis phenomenon triggered by Mn Na · ${\mathrm{Mn}}_{{\mathrm{Na}}}^{\mathrm{\cdot}}$ anti-site defects ( Mn Na · ${\mathrm{Mn}}_{{\mathrm{Na}}}^{\mathrm{\cdot}}$ -ASD), namely, the occupation of Mn2+ in the Na2 vacancies in NMTP, leads to sluggish diffusion kinetics and low energy efficiency. This study employs an innovative electronic confinement-restrained strategy to achieve the regulation of Mn Na · ${\mathrm{Mn}}_{{\mathrm{Na}}}^{\mathrm{\cdot}}$ -ASD. Partial replacement of titanium (Ti) with electron-rich vanadium (V) favors strong electronic interactions with Mn2+, restraining Mn2+ migration. The results suggest that this strategy can significantly increase the vacancy formation energy and migration energy barrier of manganese (Mn), thus inhibiting Mn Na · ${\mathrm{Mn}}_{{\mathrm{Na}}}^{\mathrm{\cdot}}$ -ASD formation. As proof of this concept, an Na-rich Na3.5MnTi0.5V0.5(PO4)3 (NMTVP) material is designed, wherein the electronic interaction enhanced the redox activity and achieved more Na+ storage under high-voltage. The NMTVP cathode delivered a reversible specific capacity of up to 182.7 mAh g-1 and output an excellent specific energy of 513.8 Wh kg-1, corresponding to ≈3.2 electron transfer processes, wherein the energy efficiency increased by 35.5% at 30 C. Through the confinement effect of electron interactions, this strategy provides novel perspectives for the exploitation and breakthrough of high-energy-density cathode materials in Na-ion batteries.

Hydrophilic-Hydrophobic Network Hydrogels Achieving Optimal Strength and Hysteresis Balance.

The biocompatibility and adaptability of hydrogels make them ideal candidates for use as artificial tendons and muscles in clinical applications, where both muscle-like strength and low hysteresis are essential. However, achieving a balance between a high strength and low hysteresis in hydrogels remains a significant challenge. Herein, we demonstrated a self-assembly process of heterogeneous hydrogels to meet the dilemma. And the hydrogels are composed of both hydrophilic and hydrophobic polymers. The hydrophilic network absorbs water, causing phase separation into a water-rich phase and a water-poor phase, while hydrophobic polymers and entanglement of the network arrest phase separation. Our results demonstrated that these hydrogels achieve remarkable mechanical properties, with a strength of 848.8 kPa, a low energy loss of 19.6 kJ/m3, and minimal hysteresis (0.046) during loading-unloading cycles. The reinforcing mechanisms underlying these properties are attributed to crystallization, molecular entanglement, and chain rearrangement induced by stretching. Furthermore, the combination of hydrophilic and hydrophobic networks is exceedingly rare in reported hydrogels.

An analytical approach for determining contact angle hysteresis on smooth, micropillared, and micropored homogeneous surfaces.

HYPOTHESIS: Numerous theoretical models have been developed from various research perspectives, including free energy analysis, force balance, and contact line dynamics, to elucidate the contact angle hysteresis on solid surfaces, especially for superhydrophobic surfaces. However, these models can produce inconsistent predictions, and few of them account for contact angle hysteresis on smooth and microstructured surfaces simultaneously. THEORY: Formulas for advancing and receding free energy barriers of drops on different solid surfaces were derived, and then these formulas were simplified by incorporating the geometric constraint equation of drops, leading to an establishment of analytical models. FINDINGS: This study presented a unified approach for deriving analytical models of contact angle hysteresis for various wetting systems, including drops on smooth homogeneous surfaces, Cassie drops on micropillared and micropored homogeneous surfaces, and Wenzel drops on micropillared homogeneous surfaces. The established models revealed a significant impact of frictional tension, and of the change in free energy during drop motion, on the free energy barriers. These models were fully derived thermodynamically without subsequent theoretical modifications and found to agree well with experimental results. Some of the models in this study were validated using other existing models, despite the models having been developed using completely different approaches.

Hysteresis response of carbon release and nitrate reduction in polymer denitrification systems.

Polymer denitrification has received much attention in the field of advanced wastewater treatment. It can release carbon source stably during long-term operation, which can be used as electron donor for denitrification. However, the response of the polymer denitrification system to the transient changes of nitrate is not sufficiently disclosed yet. In this study, the response of a polymer denitrification system to nitrate was comprehensively investigated through a series of experiments. Therefore, real-time response and hysteresis response phenomena were identified. The time dependence of microorganisms in the system and the recovery of the hysteresis response were elucidated. The experimental results revealed distinct response patterns before and after the hysteresis tipping point. The denitrifying microorganisms, which showed a high adaptive capacity, exhibited a real-time response over a range of low nitrate concentration variations (∼20-30 mg/L). In contrast, microbial recovery is poor over a range of high nitrate concentration variation (∼35-40 mg/L), which is referred to as a hysteresis response. Finally, the hysteresis response mechanism was revealed by monitoring the recovery of denitrification enzymes, gene and microbial communities. The results showed that transient shocks of high nitrate loads affect microbial community structure stability, denitrifying enzyme activity and gene expression. Meanwhile, the abundance of Microbacterium associated with carbon release was reduced. The combination of these factors leads to a hysteresis response in denitrification and carbon release. This work contributes to a deeper understanding of the hysteresis behavior in polymer denitrification systems, offering critical insights for optimizing system performance and improving nitrogen removal efficiency.

Novel three-stage microalgal cultivation system for lipid production utilizing nutrients derived from refinery waste.

The pollution and transformation of refineries are receiving increasing attention. The carbonic anhydrase in Tetradesmus obliquus was found exhibiting a hysteresis phenomenon in response to periodic changes in the composition of external carbon sources, with a surge in inorganic carbon concentration stressing the carbonic anhydrase activity to increase by 6-9 times. On this basis, a novel three-stage culture system of T. obliquus was proposed, which mainly uses refinery waste as the nutrients. By controlling the nutrient content in the environment, especially the composition of carbon sources, microalgae could sequentially complete rapid biomass accumulation, efficient inorganic carbon assimilation, and oil production. Compared to a single-environment culture system, the biomass yield increased by 1.34 times, the oil content increased by more than 6%, and the oil productivity increased by 2.08 times. Above findings may lay a partial theoretical foundation for the future evolution of traditional refineries towards "fossil-algal-biomass" hybrid refineries.

Mitigating the Kinetic Hysteresis of Co-free Ni-rich Cathodes via Gradient Penetration of Nonmagnetic Silicon.

Co-free Ni-rich layered oxides are considered a promising cathode material for next-generation Li-ion batteries due to their cost-effectiveness and high capacity. However, they still suffer from the practical challenges of low discharge capacity and poor rate capability due to the hysteresis of Li-ion diffusion kinetics. Herein, based on the regulation of the lattice magnetic frustration, the Li/Ni intermixing defects as the primary origin of kinetic hysteresis are radically addressed via the doping of the nonmagnetic Si element. Meanwhile, by adopting gradient penetration doping, a robust Si-O surface structure with reversible lattice oxygen evolution and low lattice strain is constructed on Co-free Ni-rich cathodes to suppress the formation of surface dense  barrier layer. With the remarkably enhanced Li-ion diffusion kinetics in atomic and electrode particle scales, the as-obtained cathodes (LiNixMn1-xSi0.01O2, 0.6 ≤ x ≤ 0.9) achieve superior performance in discharge capacity, rate capability, and durability. This work highlights the coupling effect of magnetic structure and interfacial chemicals on Li-ion transport properties, and the concept will inspire more researchers to conduct an intensive study.

Mechanical Properties of Latex-Modified Cement Stone under Uniaxial and Triaxial Cyclic Loading.

During the cyclic injection and extraction process in underground storage wellbores, the cement sheath undergoes loading and unloading stress cycles. In this study, we investigated the mechanical properties of latex-modified cement stone (LMCS), widely used in oil and gas wells, through uniaxial and triaxial cyclic loading and unloading tests. The aim of the study was to determine the effect of various loading conditions on the compressive strength and stress-strain behavior of LMCS. The results show that the stress-strain curve of LMCS exhibits a hysteresis loop phenomenon, with the loop intervals decreasing throughout the entire cyclic loading and unloading process. As the number of cycles increases, the cumulative plastic strain of the LMCS increases approximately linearly. Under uniaxial cyclic loading and unloading conditions, the elastic modulus tends to stabilize. However, under triaxial conditions, the elastic modulus increases continuously as the number of cycles increases. This result provides data for engineering predictions. Furthermore, a comparison of the uniaxial and triaxial cyclic loading and unloading of LMCS shows that its cumulative plastic strain develops rapidly under uniaxial conditions, while the elastic modulus is larger under triaxial conditions. These findings provide a valuable reference for constructing underground storage wellbores.

Preparation and Properties of Nb5+-Doped BCZT-Based Ceramic Thick Films by Scraping Process.

A bottleneck characterized by high strain and low hysteresis has constantly existed in the design process of piezoelectric actuators. In order to solve the problem that actuator materials cannot simultaneously exhibit large strain and low hysteresis under relatively high electric fields, Nb5+-doped 0.975(Ba0.85Ca0.15)[(Zr0.1Ti0.9)0.999Nb0.001]O3-0.025(Bi0.5Na0.5)ZrO3 (BCZTNb0.001-0.025BiNZ) ceramic thick films were prepared by a film scraping process combined with a solid-state twin crystal method, and the influence of sintering temperature was studied systematically. All BCZTNb0.001-0.025BiNZ ceramic thick films sintered at different sintering temperatures have a pure perovskite structure with multiphase coexistence, dense microstructure and typical dielectric relaxation behavior. The conduction mechanism of all samples at high temperatures is dominated by oxygen vacancies confirmed by linear fitting using the Arrhenius law. As the sintering temperature elevates, the grain size increases, inducing the improvement of dielectric, ferroelectric and field-induced strain performance. The 1325 °C sintered BCZTNb0.001-0.025BiNZ ceramic thick film has the lowest hysteresis (1.34%) and relatively large unipolar strain (0.104%) at 60 kV/cm, showing relatively large strain and nearly zero strain hysteresis compared with most previously reported lead-free piezoelectric ceramics and presenting favorable application prospects in the actuator field.

Flexible Artificial Tactility with Excellent Robustness and Temperature Tolerance Based on Organohydrogel Sensor Array for Robot Motion Detection and Object Shape Recognition.

Hydrogel-based flexible artificial tactility is equipped to intelligent robots to mimic human mechanosensory perception. However, it remains a great challenge for hydrogel sensors to maintain flexibility and sensory performances during cyclic loadings at high or low temperatures due to water loss or freezing. Here, a flexible robot tactility is developed with high robustness based on organohydrogel sensor arrays with negligent hysteresis and temperature tolerance. Conductive polyaniline chains are interpenetrated through a poly(acrylamide-co-acrylic acid) network with glycerin/water mixture with interchain electrostatic interactions and hydrogen bonds, yielding a high dissipated energy of 1.58 MJ m-3, and ultralow hysteresis during 1000 cyclic loadings. Moreover, the binary solvent provides the gels with outstanding tolerance from -100 to 60 °C and the organohydrogel sensors remain flexible, fatigue resistant, conductive (0.27 S m-1), highly strain sensitive (GF of 3.88) and pressure sensitive (35.8 MPa-1). The organohydrogel sensor arrays are equipped on manipulator finger dorsa and pads to simultaneously monitor the finger motions and detect the pressure distribution exerted by grasped objects. A machine learning model is used to train the system to recognize the shape of grasped objects with 100% accuracy. The flexible robot tactility based on organohydrogels is promising for novel intelligent robots.

Tailor-made polymer tracers reveal the role of clay minerals on colloidal transport in carbonate media.

HYPOTHESIS: Host rock weathering and incipient pedogenesis result in the exposition of minerals, e.g., clay minerals in sedimentary limestones. Once exposed, these minerals provide the surfaces for fluid-solid interactions that control the fate of dissolved or suspended compounds such as organic matter and colloids. However, the functional and compositional diversity of organic matter and colloids limits the assessment of reactivity and availability of clay mineral interfaces. Such assessment demands a mobile compound with strong affinity to clay surfaces that is alien to the subsurface. EXPERIMENT: We approached this challenge by using poly(ethylene glycol) (PEG) as interfacial tracer in limestone weathering experiments. FINDINGS: PEG adsorption and transport was dependent on the availability of clay mineral surfaces and carbonate dissolution dynamics. In addition, PEG adsorption featured adsorption-desorption hysteresis which retained PEG mass on clay mineral surfaces. This resulted in different PEG transport for experiments conducted consecutively in the same porous medium. As such, PEG transport was reconstructed with a continuum-scale model parametrized by a Langmuir-type isotherm including hysteresis. Thus, we quantified the influence of exposed clay mineral surfaces on the transport of organic colloids in carbonate media. This renders PEG a suitable model colloid tracer for the assessment of clay surface exposition in porous media.

Effect of upper eyelid blepharoplasty surgery on cornea biomechanics and ocular surface.

PURPOSE: To evaluate the changes in corneal biomechanical properties and tear film layer analysis after upper eyelid blepharoplasty surgery. METHOD: Sixty eyes of 30 patients were included in our prospective study. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure (IOPcc) and Goldmann intraocular pressure (IOPg) measurements were taken with the Ocular Response Analyzer (ORA) device at the preoperative, postoperative 1st and 3rd months. The ocular surface was evaluated with tear breakup time (TBUT) and Ocular Surface Disease Index (OSDI) scores. Lid crease (LC), margin-to-reflex distance 1 (MRD1), and palpebral fissure height (PFH) were evaluated at each visit. RESULTS: In the ORA analysis, in the 1st month CH value was found to be significantly lower than the preoperative value (preoperative 13.39 ± 6.08 mmHg; 1st month 10.74 ± 1.94 mmHg, p = 0.011). In addition, there was a statistically significant decrease in the 3rd month value compared to the preoperative values (10.46 ± 1.69 mmHg, p = 0.021). However CRF decreased postoperatively, no statistical difference was detected (preop 12.59 ± 3.84; 1st month 11.94 ± 3.04; 3rd month 9.78 ± 1.74; p = 0.149). While there was a decrease in IOPcc and IOPg in the postoperative period, no statistical difference was detected (respectively p = 0.96, p = 0.71). In the postoperative 1st month, TBUT increased significantly (p = 0.024). When those with a TBUT value below 10 were considered dry eye, significant decrease was observed in the percentage of dry eye in the first postoperative month (p = 0.027). Although the dry eye percentage decreased in the 3rd month compared to the preoperative percentage, no statistical difference was detected (p = 0.125). There was a significant decrease in the number of those with an OSDI score above 13 in the first month (p = 0.004). CONCLUSION: In our study, a decrease in ORA values was observed after blepharoplasty, with only CH being statistically significant. Reducing the load on the cornea after surgery may change the corneal biomechanics. These changes should be taken into consideration after eyelid surgery, especially in patients who may require glaucoma follow-ups.

Enhancing Perovskite Solar Cell Performance through Propylamine Hydroiodide Passivation.

In recent years, the power conversion efficiency of perovskite solar cells has increased rapidly. Perovskites can be prepared using simple and cost-effective solution methods. However, the perovskite films obtained are usually polycrystalline and contain numerous defects. Passivation of these defects is crucial for enhancing the performance of solar cells. Here, we report the use of propylamine hydroiodide (PAI) for defect passivation. We found that PAI can result in higher-efficiency cells by reducing the defects and suppressing non-radiative recombination. Consequently, n-i-p perovskite solar cells with a certificated efficiency of 21% were obtained. In addition, PAI exhibited excellent performance in p-i-n devices by serving as a buried interface layer, leading to an improved efficiency of 23%.

Precursor-film-driven ultra-early depinning of the three-phase contact line.

HYPOTHESIS: Despite its importance in colloid and interface science, contact line pinning remains poorly understood, especially in the presence of a precursor film. We hypothesized that this is due to a lack of an experimental method capable of directly observing their physics at the nanoscale. METHODS: Using coherence scanning interferometry, we visualized the three-dimensional behavior of contact lines with a precursor film near a nanogroove structure composed of flat terrace surfaces and steps with an inclination angle of 30° while achieving nanoscale vertical resolution. FINDINGS: We found that even when the contact line is pinned at the edge of the step, the precursor film is not and advances beyond the edge. Furthermore, we discovered that the precursor film has two distinct effects on contact line motion. Specifically, the precursor film facilitates depinning when the contact line descends the step - a contact angle change was 0.9°, only 3.0% of the value predicted by a classical theory of contact angle at a solid edge. This ultra-early depinning is attributed to the formation of a new liquid film past the edge, driven by the progression of the precursor film that overcomes the pinning effect. In contrast, when the contact line ascends the step, the precursor film acts as a resistance to movement due to steric interaction.

Enhancing the Sodium Storage Performance of Na4MnCr(PO4)3 through the Manipulation of Intrinsic Site Occupation Defects.

Manganese-based NASICON-type compounds are promising as high-energy-density cathodes for sodium-ion batteries. However, the structural defects of Mn ions inside the crystal framework reduce the sodium storage capacity, voltage plateau, and cyclic stability of the cathodes. Here, a strategy to inhibit the Mn ion defects of Na4MnCr(PO4)3 has been proposed by using different phosphate sources. It is found that Na4MnCr(PO4)3 prepared with NH4H2PO4 (NMCP-N) exhibits less noticeable voltage hysteresis than that of Na4MnCr(PO4)3 prepared with H3PO4 (NMCP-H), indicating that the site occupation defects of Mn ions in the Na4MnCr(PO4)3 crystal structure are successfully suppressed, as confirmed by theoretical calculations and structural refinements. In the case of NMCP-N, a capacity of 109.7 mAh g-1 is delivered at 0.01 A g-1, and 54.2% capacity retention can be kept after 500 cycles at 0.5 A g-1, which is much better than that of the counterpart of NMCP-H (a lower capacity of 96.1 mAh g-1 and poorer cyclability of only 22.8% capacity retention after 500 cycles), showing that the structure defects strongly affect the sodium storage properties of Na4MnCr(PO4)3 cathodes. This work provides an effective strategy to manipulate the structure defects of Mn-based NASICON-type cathode materials to enhance their electrochemistry.

A brief review of microstructure design in transition metal-based magnetocaloric materials.

Magnetic cooling, a solid-state refrigeration technology based on the magnetocaloric effect, has attracted significant attention in space cooling due to its high energy-efficiency and environmental friendliness. Transition metal-based magnetocaloric materials (MCMs) with the merit of low-cost have emerged as promising candidates for efficient magnetic refrigeration applications. This review explores the intricate relationship between microstructure and multiple properties (e.g. magnetocaloric properties, mechanical stability, thermal conductivity, and functional reversibility) of these materials. A variety of microstructural manipulation approaches (e.g. crystallographic texture, precipitates, micropores, atomic-scale defects, size effect, and composites) are examined for their effects on the comprehensive performance of MCMs. We show that microstructure design provides an effective tool to achieve excellent performance in multiple aspects, which may facilitate the commercialization of transition-metal based MCMs.

Ultrastretchable, Ultralow Hysteresis, High-Toughness Hydrogel Strain Sensor for Pressure Recognition with Deep Learning.

Hydrogel, as a promising material for a wide range of applications, has demonstrated considerable potential for use in flexible wearable devices and engineering technologies. However, simultaneously realizing the ultrastretchability, low hysteresis, and high toughness of hydrogels is still a great challenge. Here, we present a dual physically cross-linked polyacrylamide (PAM)/sodium hyaluronate (HA)/montmorillonite (MMT) hydrogel. The introduction of HA increases the degree of chain entanglement, and the addition of MMT acts as a stress dissipation center and cross-linking agent, resulting in a hydrogel with high toughness and low hysteretic properties. This hydrogel synthesized by a simple strategy exhibited ultrahigh stretchability (3165%), high breaking stress (228 kPa), high toughness (4.149 MJ/m3), and ultralow hysteresis (≈2% at 100% of strain). The fabricated hydrogel flexible strain sensors possessed fast response and recovery times (62.5:75 ms), a wide strain detection range (2000%), a strain detection limit of 1%, and excellent cycling stability over 500 cycles. Furthermore, the hydrogel flexible strain sensor can be used for human motion monitoring, gesture recognition, and pressure recognition assisted by deep learning algorithms, showing enormous promise for applications.