Hydrodynamic cavitation technology is gradually gaining widespread application,and the accurate and efficient extraction of structural characteristics of cavitation clouds contributes to a better understanding of the internal mechanisms of cavitation.In this study,high-speed imaging experiments were conducted to reveal the characteristics of cavitation phenomena within a jet oscillator through grayscale value analysis.Additionally,the dynamic mode decomposition method(DMD) was employed to conduct an in-depth exploration of the transient flow field inside the oscillator,investigating the coherent structures and frequency characteristics of cavitation clouds within the oscillator.Furthermore,different dominant structures were extracted,and the overall cyclic dynamics relationship with cloud cavitation under shedding frequency was discovered.Finally,using the DMD method,this study accurately extracted the dominant frequencies and modal characteristics,revealing that the energy of the oscillator mainly concentrates in the first two modes,forming larger coherent structures,while higher-frequency modes contain less energy.These experimental results provide important experimental and theoretical foundations for further research into the mechanisms of jet cavitation flow.

Most simple four-dimensional chaotic systems produce chaotic attractors;only three different phase planes have significant chaotic attractor properties.The simple four-dimensional chaotic system constructed in this study can generate six two-dimensional attractor phase diagrams and has complex chaotic properties.The phase diagram,Lyapunov exponential spectrum,bifurcation diagram,0-1 test diagram and Poincare cross section diagram are used to verify the abundant dynamic characteristics of the system.Multisim is used to simulate the system,and the results show that the circuit simulation is in agreement with the numerical analysis,which proves the physical realization of the system.Finally,a robust synchronization control scheme is designed,which proves theoretically that the driving-response system can achieve synchronization.The synchronization controller is applied to chaotic masking secure communication,which proves that the method has good security and reliability.

The requirement of the flywheel energy storage device is to ensure a constant voltage of the bus capacitor during the charging and discharging processes.Aiming at the problems of non-linearity and poor robustness under traditional voltage outer loop PI control,an improved sliding mode voltage square control is proposed.The system achieves global linearization control,and improves the robustness of the system in a wide range of speed regulation.In addition,the sign function of the current sliding mode inner loop is changed to a relatively saturated function.On the basis of retaining excellent robustness,the system chattering and harmonic effects are reduced.The results show that the proposed control strategy has a faster response speed and better anti-interference ability than traditional voltage control.

Using lignocellulose to produce fuel and chemicals is one of the effective ways to solve the current energy crisis.Although the pretreatment technology of lignocellulose has been widely studied,the high energy demand,high cost,and limitations of equipment corrosion resistance technology of traditional pretreatment technology have spurred the development of new pretreatment processes.The emergence of deep eutectic solvents (DES)effectively solves these problems and greatly improves the conversion efficiency of lignocellulose.At present,the application and research of binary deep eutectic solvents (BDES)is more extensive,the more efficient and targeted ternary deep eutectic solvents (TDES) are also gradually developing.In this study,TDES were systematically classified (including TDES containing alcohols and acids,TDES containing organic molecular compounds,TDES containing metal halides and TDES containing two different acids).The research progress of the above TDES in improving enzymatic hydrolysis performance after lignocellulose pretreatment was discussed;the combined pretreatment methods were reviewed.The potential application of DES in different research directions was prospected.

Terpenoids,natural products formed from isopentenyl diphosphate (IPP)and dimethylallyl diphosphate (DMAPP)as precursors,are almost ubiquitous in all organisms,with medicinal plants being predominant.They find wide applications in pharmaceuticals,food,chemical,and energy industries.The extraction from plants and chemical synthesis are commonly employed methods to obtain terpenoids.However,both methods suffer from drawbacks such as low efficiency,unstable quality,and high costs.These limitations clearly cannot meet the increasing demand for terpenoids.With the rapid development of synthetic biology techniques,significant progress has been made in engineering microorganisms for the synthesis of terpenoids,particularly yeast cells.Yeast cells,owing to their similar structure to plant cells and mature genetic manipulation systems,have been utilized for the synthesis of various terpenoids,gradually showcasing the advantages of biosynthetic approaches.This article reviews the progress of metabolic engineering for efficient synthesis of important terpenoids using two model yeasts,Saccharomyces cerevisiae and Yarrowia lipolytica,as examples.Specifically,it summarizes various strategies for metabolic engineering,including the screening and expression of highly active terpenoid synthases,the supply and efficient utilization of key precursor acetyl-CoA,as well as strategies for enhancing the synthesis flux of direct precursors,IPP and DMAPP,while minimizing their consumption.Finally,the article concludes with a summary and outlook on the opportunities and challenges faced by yeast-based synthesis of terpenoids.

Elucidating the complex interactions that govern protein and peptide behavior in liquid-liquid phase separation (LLPS)is crucial for understanding biological functions and dysfunctions.In this study,coarse-grained molecular dynamics simulations were employed to investigate the phase separation of poly proline-arginine peptides (poly PR)with different sequences in solutions of varying concentrations and temperatures.Our findings reveal that for poly PR25 peptides with a length of 50,significant phase separation only occurs when the salt concentration reaches 2 700 mmol·L-1;below this critical concentration,no phase separation is observed.To uncover the molecular mechanisms controlling peptide phase separation,dielectric constant modifiers and hydrophobic perturbants were introduced into the peptide system.The simulation results indicate that both hydrophobic and electrostatic interactions are factors influencing the phase separation of PR25 peptides.Furthermore,the effects of temperature and variations were examined in amino acid repeat sequences on phase separation.Notably,as the temperature increases,the LLPS behavior of PR25 is significantly inhibited,and different proline-arginine sequences in poly PR result in varying degrees of phase separation.Our simulation outcomes provide novel insights for further exploring liquid-liquid phase separation.

 During the liquid-liquid phase separation (LLPS)process,salt ion concentration and crowding agents have significant impacts on protein interaction,folding,and aggregation.This study employed an optical inverted microscope,dynamic light scattering,and a Q5000 UV-Vis spectrophotometer to delve into the inductive effect of yttrium(Ⅲ)chloride (YCl3)on the phase behavior of bovine serum albumin (BSA),as well as the regulatory role of polyethylene glycol (PEG)on the phase separation of the BSA-YCl3 system.The research findings indicate that YCl3 effectively induces phase separation in BSA,forming an LLPS system between the lower critical salt concentration (C*)and the higher critical salt concentration (C**).The addition of PEG further enhances the LLPS phenomenon in this system.Additionally,dynamic light scattering experimental data reveal that YCl3 primarily interacts with BSA through electrostatic interactions,while spectrophotometer data suggest that PEG does not alter the LLPS range of the original system but rather promotes LLPS.

Spatial correlation data and distorted measurement error data are often encountered in the process of statistical modeling of environmental data in the fields of air,surface water and acoustic environment.In order to solve the problems of spatial correlation and distorted measurement error of data in actual statistical modeling,the estimation theory of partial linear spatial autoregressive model with distorted measurement error is studied.The influence of distorted measurement error is eliminated by conditional absolute mean calibration,which avoids the imposition of non-zero expectation conditions on variables.By using the calibrated variables and combining B-spline approximation technique,orthogonal projection method and two-stage least squares method,the endogeneity problem in the model is solved.The proposed method eliminates the influence of the non-parametric part on the variable selection of the parametric part,and ensures the effectiveness and consistency of the proposed estimators.Under certain conditions,the asymptotic normality of the parameter estimation vector of the linear part and the optimal convergence rate of the non-parametric function are proved.The results obtained will further improve the theoretical system of spatial data statistical model,contribute to a more accurate understanding of data patterns and relationships in practical problems,and provide a new reference method for spatial data modeling in environmental science,biomedicine,social science and other fields.

A fuzzy relation is a generalization of a classical binary relation,which is an important tool for dealing with fuzziness related problems.Aggregation of fuzzy relations has a wide range of applications in the fields of data mining,engineering design,and decision analysis.This paper focuses on the properties of fuzzy relations (reflexivity,symmetry,transitivity,connectedness,etc.)in the aggregation process,discusses the problem of preserving the properties of fuzzy relations as well as fuzzy ordinal relations by different aggregation operators.Finally,gives an example of solving a multi-criteria decision-making problem by using fuzzy ordinal relations.