Dynamic Mechanism Research Articles

Falling, deformation, and coalescence of droplet in model waxy oil under an electric field

Electrocoalescence technology can efficiently dehydrate waxy crude oil but the mechanisms are still unclear. Herein, the continuous microscopic behaviors of droplet falling, deformation, and coalescence were experimentally investigated to clarify the dynamic response mechanism of droplet in waxy oil under an electric field. The results showed the droplet falling under both gravity and electrostatic attraction to deform by the electric field force. Moreover, the expansion and clamping of the liquid bridge resulted from the competition between electric field force and capillary force. However, the precipitated wax crystals reduced the kinetic energy of the droplet and affected its external circulation, thus delaying the falling time. In addition, the wax crystals with interfacial activity adsorbed on the oil-water interface and cross-linked to form a spatial network structure, thereby weakening droplet deformation, hindering liquid film drainage, and inhibiting liquid bridge expansion. Importantly, the droplet adsorbed wax crystals exhibited interfacial elasticity, which makes them more inclined to partial coalescence. The low-frequency pulsed direct current (PUDC) electric field with high strength intermittent effect displayed the most obvious inhibition effect on the wax crystals. Overall, these findings look promising for future design and optimization of high-efficiency electric dehydrators and related fields.

Vortex-induced vibration of the variable cross-sectional cylinder cases in transverse direction at Re = 3900 using OpenFOAM

The one-degree-of-freedom (1-DOF) vortex-induced vibration in structures with varying cross-sectional shapes and incoming flows have been conducted using numerical simulation. The investigation centers on amplitude, frequency, spectrum, phase and fluid force coefficients. Additionally, the temporal and spatial characteristics as well as vortex dynamics mechanism are scrutinized, particularly during the cross-flow amplitude extremes. It can be indicated through studies that the cross-flow amplitudes in different incoming flows exhibit a distinctive distribution with three discernible branches. Frequency locking is found to amplify the dynamic response of the structure. Four tapered cylinder cases exhibit a delay in the location of the cross-flow amplitude extremes compared to two cylinder cases attributable to the influence of structural shear rate, which expands the upper branch. Superimposing incoming shear rate in the same direction as the structural shear rate not only enhances the cross-flow amplitude extremes but also broadens the range of forces and velocities distribution acting on the structure. Conversely, the imposition of incoming shear rate in the opposite direction to the structural shear rate leads to a contrary outcome. The incoming shear rate introduces secondary frequencies with higher energy in the spectrum characteristics of two cylinder cases, consequently promoting the amplification of the cross-flow amplitudes.

Sorting of Mountage Cocoons Based on MobileSAM and Target Detection

The classification of silkworm cocoons is essential prior to silk reeling and serves as a key step in improving the quality of raw silk. At present, cocoon classification mainly relies on manual sorting, which is labor-intensive and inefficient. In this paper, a cocoon detection algorithm S-YOLOv8_c based on the cooperation of MobileSAM and YOLOv8 for the mountage cocoons was proposed. The MobileSAM with a designed area thresholding algorithm was used for the semantic segmentation of mountage cocoon images, which could mitigate the effect of complex backgrounds and maximize the discriminability of cocoon features. Subsequently, the BiFPN was added to the neck of YOLOv8 to improve the multiscale feature fusion capability. The loss function was replaced with the WIoU, and a dynamic non-monotonic focusing mechanism was introduced to improve the generalization ability. In addition, the GAM was incorporated into the head to focus on detailed cocoon information. Finally, the S-YOLOv8_c achieved a good detection accuracy on the test set, with a mAP of 95.8%. Furthermore, to experimentally validate the sorting ability, we deployed the proposed model onto the self-developed Cartesian coordinate automatic cocoon harvester, which indicated that it would effectively meet the requirements of accurate and efficient cocoon sorting.

Flow behavior and dynamic recrystallization mechanism of a new near-alpha titanium alloy Ti-0.3Mo-0.8Ni-2Al-1.5Zr

A new near-α titanium alloy Ti-0.3Mo-0.8Ni-2Al-1.5Zr was designed based on Ti-0.3Mo-0.8Ni (TA10). The hot compression tests were carried out at temperatures of 800–970 °C and strain rates of 0.01–5 s−1. The results show that the flow softening phenomenon in the α + β phase region is more distinct than that in the single β phase region. The Arrhenius constitutive models based on strain compensation in the α+β phase region and β phase region were established respectively, and the correlation coefficient between the predicted flow peak stress values and the experimental values reached 0.99365. The hot processing map of the alloy was established, the processing parameters of the peak efficiency: 800 ≤ T ≤ 818 °C, 0.01 ≤ ε˙ ≤ 0.0235 s−1, and 960 ≤ T ≤ 970 °C, 0.01 ≤ ε˙ ≤ 0.0213 s−1. The microstructure evolution and deformation mechanism of the compressed specimens were researched by electron backscatter diffraction (EBSD) technique. There were two nucleation mechanisms for dynamic recrystallization (DRX): sub-grains growth nucleation and high angle grain boundaries (HAGBs) bulging nucleation, the former was continuous dynamic recrystallization (CDRX), and the latter was discontinuous dynamic recrystallization (DDRX). The flow stress in the α+β phase region was softened by CDRX and dynamic recovery (DRV), while the principal deformation mechanisms in the β phase region are DRV and DDRX. The dislocation strain energy and recrystallization ability at different temperatures were quantitatively analyzed by the kernel average misorientation (KAM) and the geometrically necessary dislocation (GND), and the results showed that more complete recrystallization occurred at lower temperature in the α + β phase region. The HCP slip was principally completed by prismatic ⟨a⟩ and pyramidal ⟨c+a⟩ slip systems during the hot compression, while BCC was a mixed mode of {110}, {112} and {113} multiple slips.

6Pgdh polymorphism in wild bulb mite populations: prevalence, environmental correlates and life history trade-offs.

Genetic polymorphism in key metabolic genes plays a pivotal role in shaping phenotypes and adapting to varying environments. Polymorphism in the metabolic gene 6-phosphogluconate dehydrogenase (6Pgdh) in bulb mites, Rhizoglyphus robini is characterized by two alleles, S and F, that differ by a single amino acid substitution and correlate with male reproductive fitness. The S-bearing males demonstrate a reproductive advantage. Although the S allele rapidly fixes in laboratory settings, the persistence of polymorphic populations in the wild is noteworthy. This study examines the prevalence and stability of 6Pgdh polymorphism in natural populations across Poland, investigating potential environmental influences and seasonal variations. We found widespread 6Pgdh polymorphism in natural populations, with allele frequencies varying across locations and sampling dates but without clear geographical or seasonal clines. This widespread polymorphism and spatio-temporal variability may be attributed to population demography and gene flow between local populations. We found some correlation between soil properties, particularly cation content (Na, K, Ca, and Mg) and 6Pgdh allele frequencies, showcasing the connection between mite physiology and soil characteristics and highlighting the presence of environment-dependent balancing selection. We conducted experimental fitness assays to determine whether the allele providing the advantage in male-male competition has antagonistic effects on life-history traits and if these effects are temperature-dependent. We found that temperature does not differentially influence development time or juvenile survival in different 6Pgdh genotypes. This study reveals the relationship between genetic variation, environmental factors, and reproductive fitness in natural bulb mite populations, shedding light on the dynamic mechanisms governing 6Pgdh polymorphism.

Picturing self-harm: Investigating flash-forward mental imagery as a proximal and modifiable driver of non-suicidal self-injury.

Non-suicidal self-injury (NSSI) is theorized to be reinforced by its emotional consequences. Mental images of NSSI are commonly reported as occurring prior to NSSI. Based on the known functional properties of anticipatory mental imagery as an emotional and motivational amplifier, this study investigated whether NSSI mental imagery constitutes a proximal and dynamic mechanism underpinning NSSI risk. An intensive ecological momentary assessment (EMA) study was conducted to track the occurrence and characteristics of NSSI mental imagery alongside NSSI urge and behavior in naturalistic settings. A sample of N = 43 individuals aged 17 to 24 with a history of repetitive NSSI completed EMA surveys seven times a day for 14 days. Mental preoccupation in the form of NSSI mental imagery-based flash-forwards to the actions, bodily sensations, and emotional benefits of NSSI was found to occur when NSSI urge was high but not when urge was low. Critically, objective cross-panel analyses showed that higher frequencies of NSSI imagery occurrence predicted greater future NSSI urge and increased likelihood of acting on urge, over and above current urge. Mental imagery of NSSI is not simply an epiphenomenal by-product of NSSI urge and may constitute a dynamic and proximal novel intervention target.

Interface evolution mechanism and mechanical properties of Ti311/TC4 laminated composites during hot-pressing diffusion bonding

The dual-hardness titanium alloy laminated composites exhibit high hardness and toughness, making it an ideal material for applications in ballistic protection, wear-resistant and other fields. However, the substantial difference in hardness poses a challenge in effectively bonding these alloys, potentially resulting in the emergence of cracks and a decrease in bonding strength. In this study, a new Ti5Si3-reinforced high-hardness Ti311 (475 HV) and TC4 (352 HV) titanium alloys were successfully combined by hot-pressing diffusion bonding. The synergy effects of hot-pressing temperature and deformation on the microstructural evolution and mechanical properties of the Ti311/TC4 interface were systematically studied. The metallurgical bonding interface was formed at 850 °C under 25 MPa of 15.9% deformation, with the maximum shear strength value of 606 MPa. Moreover, a continuous and discontinuous coupled dynamic recrystallization mechanism was revealed. Deformed α grains were transformed to fine recrystallized grains, and gradually grew with the help of continuous dynamic recrystallization to eliminate the original flat interface. In addition, with the occurrence of element diffusion, the interface between Ti311 and TC4 is ultimately successfully bonded. Notably, the Ti5Si3 phase played a double-edge sword effect on bonding the Ti311/TC4 interface, promoting the occurrence of continuous dynamic recrystallization of adjacent α phase in TC4, but having negative effects on element diffusion.

Dynamic event-triggered control of large-scale nonlinear systems with sensor uncertainty

In this article, the dynamic event-triggered control problem is investigated for a class of large-scale nonlinear systems subject to sensor uncertainty. The unknown nonlinearities involved in each subsystem are assumed to be bounded by time-varying continuous functions multiplied by unknown constants and unmeasured states. To estimate the unmeasured states of each subsystem, a time-varying high-gain observer is constructed. Then, a dynamic event-triggered mechanism is proposed by introducing an internal dynamic variable in triggering function. Combined with the dual-domination approach, a dynamic event-triggered output feedback controller is developed for each subsystem. Subsequently, it is proved the convergence of all states is ensured based on the Lyapunov theory and the Zeno behavior can be avoided. Eventually, an example is presented to demonstrate the effectiveness of the proposed dynamic event-triggered control scheme.

Dynamic responses and interactive failure mechanisms of carbon fiber composite face sheets/double-layer corrugated core sandwich structures under low-velocity impacts loading

A single-layer and double-layer corrugated core sandwich structure consisting of carbon fibre–reinforced polymer (CFRP) panels and aluminium alloy core layers was designed. Numerical simulations were carried out in HyperMesh/LsDyna, and the simulation results of single-layer and double-layer corrugated sandwich structure were compared with the experimental results to verify the reliability of the proposed numerical model. Compared with the results of single-layer and double-layer corrugated sandwich structure, the superiority of a double-layer corrugated sandwich structure in anti-collision performance is verified. Considering the effects of impact energy and impact position on impact force, energy absorption capacity, and failure mode, a series of low-velocity impact finite element simulations was carried out. It was found that the main failure mode of composite laminates included fibre damage, matrix damage and delamination, and core buckling. At the same impact position, the higher the impact energy, the greater the initial slopes of the contact force-time and absorbed energy-time curves, the higher the peak force, and the larger the energy absorption capacity. Under the same impact energy, when the impactor hit the wave crest of the sandwich structure, the damage to the structure was small; however, the maximum impact force on the structure was large (∼8 kN).

Development and application of safety culture analysis program: First online safety culture quantitative analysis and assessment system in China

To promote safety culture assessment, this paper developed China's first online safety culture analysis and evaluation system—Safety Culture Analysis Program (SCAP). SCAP is based on the 32 safety culture elements in the 24Model and provides two login methods: web version and WeChat mini program. It can meet the needs of individuals, groups, and enterprises to conduct safety culture assessments anytime and anywhere and provide convenience for universities to conduct safety culture experiments. The application of SCAP showed that (1) SCAP has rich functions and is highly scientific and universal. (2) The SCAP can output assessment results according to categories, such as total, personnel, safety culture elements, and individual employee requirements, which can be compared with the highest and lowest values stored in the system. This makes it easy for intuitively understanding the current evaluation status. (3) The suggestion report generated by SCAP can help assessment units improve safety culture in a targeted manner and form a dynamic mechanism cycle of “construction-evaluation-construction.” (4) In the future, SCAP will be employed in designing more targeted questions based on the characteristics of different industries and fields to balance the adaptability and specificity of the industry.

Core-Shell CoS2@MoS2 with Hollow Heterostructure as an Efficient Electrocatalyst for Boosting Oxygen Evolution Reaction.

It is imperative to develop an efficient catalyst to reduce the energy barrier of electrochemical water decomposition. In this study, a well-designed electrocatalyst featuring a core-shell structure was synthesized with cobalt sulfides as the core and molybdenum disulfide nanosheets as the shell. The core-shell structure can prevent the agglomeration of MoS2, expose more active sites, and facilitate electrolyte ion diffusion. A CoS2/MoS2 heterostructure is formed between CoS2 and MoS2 through the chemical interaction, and the surface chemistry is adjusted. Due to the morphological merits and the formation of the CoS2/MoS2 heterostructure, CoS2@MoS2 exhibits excellent electrocatalytic performance during the oxygen evolution reaction (OER) process in an alkaline electrolyte. To reach the current density of 10 mA cm-2, only 254 mV of overpotential is required for CoS2@MoS2, which is smaller than that of pristine CoS2 and MoS2. Meanwhile, the small Tafel slope (86.9 mV dec-1) and low charge transfer resistance (47 Ω) imply the fast dynamic mechanism of CoS2@MoS2. As further confirmed by cyclic voltammetry curves for 1000 cycles and the CA test for 10 h, CoS2@MoS2 shows exceptional catalytic stability. This work gives a guideline for constructing the core-shell heterostructure as an efficient catalyst for oxygen evolution reaction.

Development of a multi-layer network model for characterizing energy cascade behavior on turbulent mixing

Eddies of various sizes are visible to the naked eye in turbulent flow. Each eddy scale corresponds to a fraction of the total energy released by the turbulence cascade. Understanding the dynamic mechanism of the energy cascade is crucial to the study of turbulent mixing. In this paper, an energy cascade multi-layer network (ECMN) based on the complex network algorithm is proposed to investigate the spatio-temporal evolution of the energy cascade, covering both the inertial and dispersive ranges. The dynamic process of energy cascade is transformed into a topological structure based on the node definition and edge determination. The topological structure allows for the exploration of eddies interaction and chaotic energy transfer across scales. The model results show the intermittent and non-uniform nature of the energy cascade. Meanwhile, the scale gap found in the model verifies the fractal property of the energy evolution. We also found that scales of the generated eddies in energy cascade process are stochastic, and a synchronous energy cascade pattern is demonstrated according to the constructed framework. Furthermore, it provides a topological way to evaluate the contribution of large and small scale eddies. In addition, a network structure coefficient κ is proposed to evaluate the energy transfer strength. It agrees very well with the fluctuation of dissipation rates. All of this shows that the network model can effectively reveal the inhomogeneous properties of the energy cascade and quantify the turbulent mixing intensity based on the intermittent scale interaction. This also provides new insights into the study of fractal scales of nonlinear complex systems and the bridging of chaotic dynamics with topological frameworks.

Study on Dynamic Post-Buckling Stability of Thin-Walled Cylinders Subjected to Horizontal Vibration

Abstract As a lesson learned from the Fukushima nuclear accident, the importance of accident mitigation for beyond design basis events (BDBEs) is recognized. Excessive earthquake is a typical BDBE. During such events, the fast reactor main vessel (FRMV) is vulnerable to buckling because of its thin-walled cylindrical structure. Buckling deformation without causing immediate collapse should not be considered as a limit state in BDBEs. Instead, the objective is to achieve a stable post-buckling state. In the present study, dynamic post-buckling behavior of thin-walled cylinders under intense horizontal vibration is experimentally studied, which simulates loop-type FRMV design. Finite element method (FEM) simulation is also conducted and validated by experimental data. Based on results analysis, a global response stability after buckling is confirmed. The buckled model shows resilience to withstand catastrophic collapse even when intense excitation continues to apply. Using equivalent linear response method, dynamic mechanisms behind the stability are revealed. Due to substantial degradation of structural stiffness, the post-buckling response shifts into the out-of-phase domain such that response divergence is prevented. Meanwhile, the response is notably delayed from the input, which impedes the conversion of input energy into kinetic energy, reducing the inertial impact to the structure. These mechanisms are found to be independent of input waveforms and can be applied to a general seismic scenario. Moreover, the limit for global response stability after buckling and the effect of input frequency on the post-buckling behavior are clarified.

The Path Innovation of Regional Economic Growth: Data Analysis Based on China

AbstractInnovative development to some extent overcomes the path-dependent characteristics of knowledge proximity, and the diversity and complexity of regional knowledge and technology foster regional economic growth. This study constructs a dynamic mechanism for maximizing the enterprise profit to explore the conditions enabling regions that can achieve knowledge accumulation and technological leapfrogging. Utilizing the fitness landscape methodology based on customs data from 30 provinces in China and employing genetic algorithms, we analyze two modes of enterprises with similar and different initial conditions under varying leapfrogging scenarios. By applying profit maximization rules within the fitness landscape of the product space, we examine how to promote regional industrial transformation and upgrade. The results indicate that a larger leap range in the production of products by enterprises, reflecting stronger innovative capabilities, significantly enhances the region’s ability for industrial transformation and upgrade. There is a strong positive relationship between the initial industrial foundation and regional economic development. When regions share a similar industrial base, the complexity of regional knowledge becomes more critical. Therefore, an increase in the foundational development of industries and technology-intensive products can enhance the potential for regional path innovation. Past research has primarily been based on the path dependence theory, emphasizing that the most crucial aspect for underdeveloped economies is the accumulation and development of foundational capabilities. However, our study contends that, for emerging economies, it is crucial to enhance the diversity and complexity of knowledge and technology. Particularly, it is essential to, based on a comprehensive understanding of their own strengths, open up new areas and new arenas in development, continually shaping new growth drivers and new strengths. This emerges as a significant factor in regional growth and leapfrog development.

Dynamic Mechanism of Destination Brand Diffusion: Agent-Based Modeling and Simulation

In recent years, social media has emerged as an important channel for the dissemination of destination branding. Despite the fact that the dissemination of information through social media enables a broader audience to become acquainted with destinations, the dissemination process of trending events exhibits variances. Consequently, the precise impact of the underlying mechanisms that govern the spread of information on the efficacy of disseminating destination brand trending events remains ambiguous. In an endeavor to bridge this gap, an improved SEIR model was developed in this research to investigate the dynamic dissemination mechanisms and influencing factors of destination trending events within social media. The model was applied to simulate the diffusion mechanism of destinations’ trending events. The results show that during the dissemination process of destination trending events on social media, the proportion of users affected at different stages influences the ultimate effectiveness of information propagation. In light of these insights, this research proposes a social media trending event dissemination strategy to aid in enhancing the propagation efficiency of destination brands through existing resources.

Multiscale mechanics of polydimethylsiloxane: A comparison of meso‐ and micro‐cyclic deformation behavior

AbstractDespite plenty of static and dynamic mechanical measurements and modeling for bulk polydimethylsiloxane (PDMS) specimens, a notable gap exists in comprehensively understanding the dynamic mechanics under large cycle, low strain conditions, especially for microscale samples. This study integrates tensile testing and nanoindentation techniques to compare dynamic mechanical response for bulk PDMS samples and μ‐pillars. The results from cyclic tensile testing, which involved up to 10,000 cycles at a strain range of 10%–20%, indicate a stabilization of energy dissipation rate after the initial 25 cycles. This attributes to stress relaxation and strain hardening, validating by rapid dual‐phase exponential decay in maximum stress, coupled with an incremental increase in elastic modulus. In comparison to tensile testing, μ‐pillars exhibited a 0.82% reduction in stiffness, stabilizing ~600th cycle. Concurrently, there was an approximately twofold increase in approaching distance during the initial 120 cycles, and an approximately fourfold increase in dissipated energy over the first 80 cycles, before reaching a plateau. This lagging hysteresis effect attributes to the distribution of the resultant force, including top tension, bottom compression, and base tilt. Overall, this study illuminates temporal mechanical deformations in PDMS under two application scenarios, enhancing our understanding of PDMS mechanical behavior.

DRP1 inhibition-mediated mitochondrial elongation abolishes cancer stemness, enhances glutaminolysis, and drives ferroptosis in oral squamous cell carcinoma.

Mitochondrial dynamics play a fundamental role in determining stem cell fate. However, the underlying mechanisms of mitochondrial dynamics in the stemness acquisition of cancer cells are incompletely understood. Metabolomic profiling of cells were analyzed by MS/MS. The genomic distribution of H3K27me3 was measured by CUT&Tag. Oral squamous cell carcinoma (OSCC) cells depended on glucose or glutamine fueling TCA cycle were monitored by 13C-isotope tracing. Organoids and tumors from patients and mice were treated with DRP1 inhibitors mdivi-1, ferroptosis inducer erastin, or combination with mdivi-1 and erastin to evaluate treatment effects. Mitochondria of OSCC stem cells own fragment mitochondrial network and DRP1 is required for maintenance of their globular morphology. Imbalanced mitochondrial dynamics induced by DRP1 knockdown suppressed stemness of OSCC cells. Elongated mitochondria increased α-ketoglutarate levels and enhanced glutaminolysis to fuel the TCA cycle by increasing glutamine transporter ASCT2 expression. α-KG promoted the demethylation of histone H3K27me3, resulting in downregulation of SNAI2 associated with stemness and EMT. Significantly, suppressing DRP1 enhanced the anticancer effects of ferroptosis. Our study reveals a novel mechanism underlying mitochondrial dynamics mediated cancer stemness acquisition and highlights the therapeutic potential of mitochondria elongation to increase the susceptibility of cancer cells to ferroptosis.

Study on the grain evolution of austenitic steel for nuclear power during hot working based on large area EBSD mapping

To address the issue of non-standard grain sizes and difficult control of uniformity in the manufacturing of large, complex-shaped nuclear power pipelines. In this paper, double wedge-shaped samples of X2 CrNiMo 18.12 (CN) austenitic stainless steel were hot deformed at 1000 °C, 1100 °C, and 1180 °C to obtain deformation samples with a gradient strain, and the deformation sample at 1180 °C was subjected to solid solution treatment at 1060 °C × 4 h (water quenching; the measured cooling rate of water cooling was approximately 4400 °C/min). Large-area electron backscattered diffraction mapping technology was used to characterize the 80 mm × 5 mm full-area range of samples. The initiation sequence of various dynamic recrystallization mechanisms and the grain evolution under continuous effective strain conditions at a hot deformation temperature of 1000–1180 °C were investigated. The influence of the hot deformation process parameters on the grains after solid solution treatment was examined, the process interval for the generation of severe mixed grains was determined. The results show that the recrystallization behavior of X2 CrNiMo 18.12 (CN) austenitic stainless steel is mainly determined by a combination of recrystallization mechanisms dominated by discontinuous dynamic recrystallization, supplemented by continuous dynamic recrystallization, twinning-induced dynamic recrystallization, and geometrical dynamic recrystallization during the hot deformation process at 1000–1180 °C. The effective strain intervals of the solid solution sample that produces severely mixed grains are in the range of 0.11–0.22 mm/mm, with the probability of producing severely mixed grains with an effective strain in the range of 0.13–0.14 mm/mm reaching 74%.

Insight into adsorption properties and mechanism of geopolymer adsorbents with inherent alkali release for tetracycline

The crux to practical application of geopolymer adsorbents for antibiotics that are easily protonated and deprotonated is to clarify the dynamic adsorption mechanism of geopolymer with intrinsic alkaline release. The adsorption properties, adsorption mechanism, adsorption-desorption cycle and waste adsorbent regeneration based on the geopolymer adsorbent for adsorbing tetracycline under the spontaneous dynamic pH conditions were systematically investigated by experiment, characterization and density functional theory. The results confirmed that the structures of tetracycline depended on dynamic pHs of adsorption systems changed by geopolymer adsorbent. The electrostatic interaction assisted by hydrogen-bonding and n-π interaction dominated the adsorption process when the dynamic pHs were less than 7. And the hydrogen-bonding and n-π interaction provided the possibility of weak adsorption effect in highly alkaline environments. The geopolymer powder exhibited outstanding adsorption efficiency (∼95.62%, 30 min) due to the strong electrostatic adsorption between electronegative skeleton of geopolymer and zwitterions species tetracycline under dynamic pH range of 4–6.3 and fitted the pseudo-second-order model. The outstanding competitive adsorption properties in NaCl solution, adsorption (4 times)-desorption (3 times) cycle properties and regenerative property of waste adsorbent were exhibited. The mechanism study based on the dynamic pHs which is closer to actual conditions can provide important reference for practical application of easy preparation and low cost geopolymer adsorbents.

Dynamic event-triggered state estimation for discrete-time delayed switched neural networks with constrained bit rate

In this paper, a class of discrete-time delayed switched neural networks with dynamic event-triggered mechanism (DETM) and constrained bit rate is considered. In order to reduce the transmission frequency and alleviate the unnecessary resource loss between sensor and estimator, a DETM is proposed. The data transmission from sensor to estimator is realized through constrained bit rate channel. Therefore, in order to reflect the bandwidth allocation rules of accessible neurone nodes, a bit rate constraint model is introduced and an encoding-decoding mechanism is developed. This paper is concerned with the strategy of average dwell time (ADT) and linear matrix inequality, then sufficient conditions for the exponential ultimate boundedness of switched neural networks with DETM and constrained bit rate are proposed. Finally, an example is given to prove the effectiveness of the results.