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In recent years, non-aqueous iron-based ionic liquid (Fe-IL) desulfurization technology has garnered widespread attention for its avoidance of the excessive oxidation of hydrogen sulfide in aqueous systems. However, the hydrogen bond network in ionic liquids restricts molecular motion, resulting in poor reactivity of Fe-IL. In this work, the chelated Fe-ILs (BmimFeEDTA and BZKFeEDTA) were synthesized and dissolved in PEG200 to construct chelated iron-based deep eutectic solvents (Bm-Fe-DES, BZK-Fe-DES). 1,3-Dimethyl-2-imidazolidinone (DMI), as a conjugated active ligand, was introduced to enhance the catalytic oxidation of H2S by the two Fe-DESs. After five cycles, both Fe-DES/DMI systems exhibited excellent desulfurization and regeneration performance. POM and FT-IR analyses revealed that BZKFeEDTA with a long carbon chain exhibited a more ordered spatial structure, which was more conducive to the cycling of Fe(III) and Fe(II). CV, Py-IR, bond length analysis, and LUMO-HOMO energy gap indicated that DMI weakens the limitation of EDTA to Fe(III) by coordinating with Fe(III), which significantly enhances the catalytic activity of Fe-DES. UV–vis and CPA analysis demonstrated the transfer of π electrons from DMI to the EDTA ligand, facilitating the loss of electrons from [Fe(II)EDTA]2-. Therefore, the two types of chelated iron-based deep eutectic solvents prepared in this work have great application potential in the field of hydrogen sulfide catalytic oxidation.

Batch steganography regarding to image-selection and payload-allocation has gained increasing attention due to the secure demanding of data hiding of real scenario. However, due to the predefined selection mechanism, the chosen images are always complex which means that the diversity of the selected cover set is finite. In this paper, we develop a diverse and secure batch steganography scheme including the model-based generation and double-layered payload assignment. To construct the diverse image set, we use the Kullback-Leibler (KL) divergence to quantify the diversity increment and, relying on steganographic distortion, we select multiple image subsets (class) to create the diverse cover set in which each subset is modeled as the normal distribution with proper model parameters. Depending on the distortion of image subset, we assign the payload into all subsets with between-class allocation. Moreover, for the assigned payload of each subset, we introduce the linear model to achieve the within-class allocation. Finally, we obtain a diverse cover set along with suitable payload. Extensive experiments demonstrate the practicality of the proposed method in diversity and, compared with other selection methods, exhibit higher security on multiple steganalytic tools.

The paper aims to study the mechanical characteristics of disintegrated carbonaceous mudstone in a triaxial stress state from a micro-perspective of particles. Based on the discrete element method (DEM), a spherical-polymer (SP) model that includes three different types of the particles (triangle-like, rectangle-like, and sphere) was proposed and combined the error diagram with R2to analyze the difference between the SP model and Ball–Ball (BB) model. Meanwhile, a sensitive analysis of micro-mechanical characteristics was carried out, which quantitatively described the sensitivity of different parameters according to stress–strain curves. The processes of deformation and failure for the disintegrated carbonaceous mudstone were finally analyzed based on the displacement diagram of the particle according to the energy theory. The results suggest that the SP model could better reflect the mechanical characteristics of disintegrated carbonaceous mudstone, for the SP models, the correlation coefficient (R2) range was larger than the BB model. From the sensitivity analysis of parameters, the decreasing rate of initial deformation modulus was 56–66% as the stiffness ratio was modified when fixing other factors. The peak strength correlated well with the tensile-shear strength ratio, stiffness ratio, and friction coefficient. The modification of abnormal-shaped particles’ volume fraction ratio could affect the peak shear strength significantly. For the disintegrated carbonaceous mudstone, the processes of deformation and failure were discussed by energy transference which particle elements go from a low-energy state to a high-energy state.

Our previous study showed that Lactiplantibacillus plantarumY42 in the biofilm state can produce more exopolysaccharides and surface-layer proteins and showed a stronger promoting effect on intestinal barrier function than that in the planktonic state. In this study, oral administration of the live/pasteurized planktonic or biofilm L. plantarumY42 and its metabolites (exopolysaccharides and surface-layer proteins) increased the expression of Occludin, Claudin-1, ZO-1, and MUC2 in the gut of the Balb/C mice after exposure to Listeria monocytogenesATCC 19115 and inhibited the activation of the NLRP3 inflammasome pathway, which in turn reduced the levels of inflammatory cytokines IL-1β and IL-18 in the serum of the mice. Furthermore, oral administration of the live/pasteurized planktonic or biofilm L. plantarumY42 and its metabolites increased the abundance of beneficial bacteria (e.g., Lachnospiraceae_NK4A136_groupand Prevotellaceae_UCG-001) while reducing the abundance of harmful bacteria (e.g., norank_f__Muribaculaceae) in the gut of the mice, in line with the increase of short-chain fatty acids and indole derivatives in the feces of the mice. Notably, biofilm L. plantarumY42 exerted a better preventing effect on the intestinal barrier dysfunction of the Balb/C mice due to the fact that biofilm L. plantarumY42 expressed more exopolysaccharides and surface-layer proteins than the planktonic state. These results provide data support for the use of exopolysaccharides and surface-layer proteins extracted from biofilm-state L. plantarumY42 as functional food ingredients in preventing intestinal barrier dysfunction.

We propose, in this paper, the preconditioned accelerated generalized successive overrelaxation (PAGSOR) iteration method for efficiently solving the large complex symmetric linear systems. To solve the nonlinear systems whose Jacobian matrices are complex and symmetric, treating the PAGSOR method as internal iteration, we construct a modified Newton-PAGSOR (MN-PAGSOR) method to provide an effective approach for solving a wide range of problems in various scientific and engineering fields. Based on the Hölder continuous condition we present the theoretical framework of the modified method, demonstrate its local convergence properties, and provide numerical experiments to validate its effectiveness in solving a class of nonlinear systems.

In this paper a simple and efficient method is developed to quench the steady state vibration of a symmetric laminated composite rectangular plate subjected to multiple harmonics with distinct excitation frequencies. The introduction of the inerter into the traditional dynamic vibration absorber enlarges the solution space for both the feasible attachment locations and the absorber parameters. For a given set of attachment locations, when the traditional vibration absorbers yield physically unrealizable absorber parameters, i.e., negative absorber parameters, an inerter-based vibration absorber can be used such that the absorber parameters become strictly positive. Using the assumed modes method, the governing equations of the laminated composite plate carrying the inerter-based dynamic vibration absorbers are first formulated. A set of constraint equations is established by enforcing nodes at user-specified locations on the plate. Harmonic excitations consisting of a single or multiple distinct excitations are considered. In addition, two attachment scenarios are analyzed: when the attachment and node locations coincide, and when they are distinct. Numerical experiments show that the absorbers parameters can be readily determined for both cases, and validate the proposed method of enforcing the desired node locations when the plate is subjected to either a single or multiple harmonic excitations.

Ultrasonic seam assisted resistance spot welding, as a new joining technology, was proposed for welding TC4 titanium alloy and Q235 mild steel with Cu interlayer (abbreviated as US-RSW-Cu), in which, the Cu interlayer was consolidated on the Q235 mild steel by ultrasonic seam welding (USW) in advance, which was subsequently connected with TC4 by the traditional standard resistance spot welding (RSW) in the following experiments. To investigate the effect of pre-USW on the interface microstructure and mechanical properties, the final joints were compared with the other joints by the traditional RSW without interlayer directly (abbreviated as RSW-D), and with a single Cu interlayer (abbreviated as RSW-Cu). The results depicted that the welding nugget in RSW-D and the flat interfacial structure in RSW-Cu were replaced by the inhomogenous interfacial structure in US-RSW-Cu due to the pre-metallurgical bonding between Cu interlayer and steel by USW, which also effectively decreased the welding defects. The Ti-Cu intermetallic compounds (IMCs) were generated at the final joints via US-RSW-Cu instead of most Ti-Fe IMCs, which improved significantly the joint properties and reduced the nanoindentation hardness at the joint interface. The final shearing force of welding joints by this method was the highest and reached 12,380 N, which was 2.68 times with original joint strength via a single RSW-D. The reaction layer near the Ti side via US-RSW-Cu contained abundant Fe atoms, forming Ti-Cu and TiFe2IMCs at this position. The final welded specimen fractured at the interfacial reaction layer near the Ti side due to the generation of TiFe2IMC. The XRD results also proved the generation of the abovementioned Ti-Cu and Ti-Fe IMCs.

In order to explore the cultivation techniques for increasing maize yield and water efficient utilization in the semi-arid area of Jilin Province, China, a field experiment was carried out in Taonan City, the semi-arid area of Jilin Province in 2020 and 2021. Common plastic film mulching (CM), degradable plastic film mulching (DM), crushed straw mulching (SM) and no mulching (CK) were set up to study the effects of surface mulching on the temporal and spatial changes of soil water and temperature, physiological characteristics of maize, maize yield and water use efficiency. The results showed that the soil water content was related to rainfall and its spatial and temporal distribution in maize growth stage. The soil water content in 0–60 cm increased with the increase of soil depth in the vertical direction, and the soil water content between treatments was SM > CM > DM > CK. The soil temperature increased first and then decreased with the growth process of maize, and gradually decreased with the deepening of the plough layer. The temperature was increased by plastic film mulching (CM > DM), and decreased by straw mulching. Different water temperature effects caused by surface mulching have different effects on the physiological characteristics, growth and yield of maize, and DM treatment was the best. DM treatment significantly increased the bleeding sap mass and cytokinin content of maize roots due to its coordinated water temperature, significantly reduced the content of soluble sugar and abscisic acid in bleeding sap compared with CK, transmitted the physiological reaction of roots upward through plant hormones and other information substances, indirectly affected the physiological and biochemical processes of shoots, and enhanced the activities of ribulose diphosphate carboxylase, phosphoenolpyruvate carboxylase and glutamine synthetase in leaves, it improved the photosynthetic performance of maize leaves, promoted the growth and development of maize and the accumulation of dry matter in each period, thereby significantly increasing maize yield by 14.13% and water use efficiency by 16.8%. The yield and water use efficiency of maize under CM treatment were 8.59% and 8.1% higher than CK respectively. However, SM treatment resulted in slow accumulation of dry matter, 8.96% yield reduction and 10.4% water use efficiency reduction due to low temperature effect in the early stage, decreased enzyme activity and photosynthetic rate, and slow growth and development. The degradable plastic film mulching can keep water and increase temperature, increase yield and improve efficiency, and reduce environmental pollution, which can provide theoretical basis and technical support for the cultivation technology model of maize yield increase and water efficient use in semi-arid areas.

The reliable Al/steel resultant welded joint with a large contact area was of great significance in electrolysis cells to produce aluminum. Herein, a large-area 6061 aluminum alloy/304 stainless steel dissimilar welds were successfully obtained by unbalanced thermal field assisted thermo-compensated resistance brazing welding(abbreviated as UTC-TC-RBW). In the present study, the heating distribution conditions of the joint were adjusted based on the introduction of the auxiliary welding current, forming an unbalanced temperature field. The whole welding temperature field of the joint was improved significantly with the increase of the auxiliary current, which promoted the interdiffusion of Al and Fe elements at the interface. Hence, the connection area between Al alloy and steel was increased gradually. The final interface between Al alloy and steel was changed to the Al(s.s) diffusion layer and Fe2Al5layer. XRD results proved the presence of these phase compositions. When the auxiliary current was 0.3 kA, the maximum thickness of the Al(s.s) diffusion layer and Fe2Al5layer reached 5.25 μm and 0.86 μm. The final load of the obtained joint with the auxiliary current of 0.3 kA was the maximum and reached 1789.7N, which was approximately 3 times that of the joints without auxiliary current.

Achieving the effective joining between Al alloy and stainless steel with a large cross-section was meaningful in the significant industry field. For this, the Al/steel dissimilar bimetal materials were manufactured by a novelty hybrid technology, named thermo-compensated resistance brazing welding. The effect of the single Zn foil and the deposited Zn coatings with cold spray technology on the bonding interface, interfacial microstructure, and mechanical properties of the final Al/steel resultant joints were systematically investigated by the relevant analysis method. The results revealed that the obvious reaction layer with main components of Al(s.s) was formed at the Al/steel joints with the single Zn foil as the interlayer. Meanwhile, the introduction of the Zn interlayer improved the temperature field of the joint, which enhanced the lap-shear load of the weld. Besides, the Zn coating was deposited at the top surface of the 304ss substrate as the interlayer to increase joint performance further. The advantage of the pre-deposition formed a better metallurgical bond between the coating and 304ss. The subsequent lap-shear load of the weld was improved with the increase of the Zn coating thickness. The maximum lap-shear load of the final joints reached 2087.6N with a Zn coating thickness of 500 μm and the interfacial structure of the joint was changed: Al alloy, reaction layer I, Al(s.s) + Al2O3, and 304ss from top to bottom. The main composition was Al(s.s) at the reaction layer I between Al alloy and coating.

To explore the effects of 6-gingerol, asarinin, and deoxyschizandrin—the main components of Zingiber officinale(Willd.) Rosc. (Gan Jiang), Asarum heterotropoidesf. var. mandshuricum(Maxim.) (Xi Xin), and Schisandra chinensis(Turcz.) Baill. (Wu Wei Zi), respectively—on an interleukin (IL)-13–induced BEAS-2B cell model in vitro.

The 6061 aluminum alloy/304 stainless steel dissimilar materials with a certain area were successfully achieved by a novelty welding method, named thermo-compensated resistance brazing welding, in which, the high-resistivity graphite was inserted as the auxiliary electrode. The effect of the welding current and welding time on the temperature field of the graphite, mechanical properties, and the fracture surface of the final Al/steel weld was investigated. The results revealed that the temperature field was generated by Joule heat based on graphite, Al alloy, and stainless steel in the welding process. The generated Joule heat was gradually extended from one point to the entire interface in the whole welding process. The temperature field and tensile-shear load of the joint were also improved with the increase of the welding parameters. The degree of diffusion surface was illustrated at the fracture, indicating the “brazing” feature. There were three diffusion regions A, B, and C on the fracture surface with the steel side of the optimal parameters. The mechanical properties of the weld mainly depended on regions B and C. The effective connection was formed at a local area of the entire interface between Al alloy and 304ss at this parameter. Al(s.s) and Fe2Al5IMC were generated at the interface. The typical inclined interfacial failure was formed after the tensile-shear test due to the heat generation mechanism. The Al(s.s), Fe(s.s), and Fe2Al5IMC were presented on the fracture surface, which was consistent with the above contents.

Graphical abstract:

Stroke is the leading cause of death and disability. Currently, there is no effective pharmacological treatment for this disease, which can be partially attributed to the inability to efficiently deliver therapeutics to the brain. Here we report the development of natural compound-derived nanoparticles (NPs), which function both as a potent therapeutic agent for stroke treatment and as an efficient carrier for drug delivery to the ischemic brain. First, we screened a collection of natural nanomaterials and identified betulinic acid (BA) as one of the most potent antioxidants for stroke treatment. Next, we engineered BA NPs for preferential drug release in acidic ischemic tissue through chemically converting BA to betulinic amine (BAM) and for targeted drug delivery through surface conjugation of AMD3100, a CXCR4 antagonist. The resulting AMD3100-conjugated BAM NPs, or A-BAM NPs, were then assessed as a therapeutic agent for stroke treatment and as a carrier for delivery of NA1, a neuroprotective peptide. We show that intravenous administration of A-BAM NPs effectively improved recovery from stroke and its efficacy was further enhanced when NA1 was encapsulated. Due to their multifunctionality and significant efficacy, we anticipate that A-BAM NPs have the potential to be translated both as a therapeutic agent and as a drug carrier to improve the treatment of stroke.

Magnetosonic (MS) waves with frequencies above the proton gyrofrequency can be locally generated by ring‐beam protons in the Martian heavy ion‐rich ionosphere. In this study, we conduct a parametric analysis to investigate the effects of heavy ion concentrations, energy (Erb), and angle (αrb) of ring‐beam protons, and wave normal angle on the excitation features of Martian ionospheric MS waves. We find the growth rates and frequency range of MS waves decrease by including O+and O2+ions but are insensitive to their relative concentrations. With increasing Erbor αrb, the growth rates of MS waves show a general dropping tendency. Meanwhile, their frequency and wavenumber range are almost unaffected by increasing Erbbut shrink to a narrower range mainly distributed in high frequencies by increasing αrb. Unstable MS waves expand to a wider wavenumber range but shrink to a narrower frequency range as they become more oblique. Magnetosonic (MS) waves are highly compressible electromagnetic emissions in space. Generally, they are locally excited by ring‐like hot protons in plasmas that lack heavy ions. However, a recent study reveals that they can also be locally excited by ring‐beam protons in the Martian heavy ion‐rich ionosphere. Motivated by these differences, we conduct a detailed parametric analysis to investigate how the heavy ion concentrations, the energy and angle of ring‐beam protons, and the wave normal angle affect the dispersion relation and growth rate of Martian MS wave. We find that O+and O2+ions lower the growth rates and frequency range of MS waves but the effects of their relative concentrations are insignificant. In addition to the heavy ions, the excitation features of MS waves strongly depend on the wave normal angle and the distribution properties of ring‐beam protons. These results deepen our understanding of the MS wave excitation features in the unmagnetized planet environment with plentiful heavy ions. O+and O2+ions lower the growth rates and frequency range of Magnetosonic (MS) waves but the effects of their relative concentrations are insignificantThe growth rates of MS waves show a general dropping tendency with increasing ring‐beam energy or angleUnstable MS waves expand to a wider wavenumber range but shrink to a narrower frequency range as they become more oblique O+and O2+ions lower the growth rates and frequency range of Magnetosonic (MS) waves but the effects of their relative concentrations are insignificant The growth rates of MS waves show a general dropping tendency with increasing ring‐beam energy or angle Unstable MS waves expand to a wider wavenumber range but shrink to a narrower frequency range as they become more oblique

Electron cyclotron harmonic (ECH) waves are electrostatic emissions with frequencies between the harmonics of the electron gyrofrequencies. Their frequency properties provide clues for understanding their generation and are keys to evaluating their scattering efficiency. Based on Magnetospheric Multiscale satellite observations, we explored the statistical frequency properties of first‐harmonic band ECH waves in the outer magnetosphere. The frequencies at the peak power of ECH waves are found to be day‐night and dawn‐dusk asymmetries, with higher values in the regions from dawn to post‐noon, and these asymmetries are more evident during weaker geomagnetic activity. Furthermore, the frequencies at the peak power of ECH waves decrease gradually with increasing |MLAT| and are positively correlated with their amplitudes at each magnetic local time or |MLAT|. Information on the frequency properties of ECH waves presented in this study can be crucial for future modeling of their contributions to magnetospheric electron dynamics. Electron cyclotron harmonic (ECH) waves are electrostatic emissions with frequencies between the harmonics of the electron cyclotron frequency. They act as major contributors to the generation of diffuse auroras in the outer magnetosphere via the pitch angle scattering of plasma sheet electrons into the atmosphere. Theoretically, such electron scattering can be quantified by quasilinear scattering rates, which are strongly controlled by the wave frequency. However, the current knowledge of their frequency properties is lacking. In this study, we statistically analyze the frequency properties of the first‐harmonic band ECH waves in the outer magnetosphere using Magnetospheric Multiscale satellite observations. The statistical results show that the wave frequency at peak power highly depends on the magnetic local time (MLT), magnetic latitude (MLAT), and wave amplitude. These new findings are of great importance in advancing our knowledge of ECH wave generation and in modeling ECH‐induced plasma sheet electron dynamics in the outer magnetosphere. ECH waves have clear frequency distribution patterns depending on the MLT, MLAT, and wave amplitudeThe frequency at the peak power is larger from dawn to post‐noon, maximized near the magnetic equator, and decreases with increasing |MLAT|The frequency at the peak power increases with the amplitude for each specific magnetic local time or |MLAT| ECH waves have clear frequency distribution patterns depending on the MLT, MLAT, and wave amplitude The frequency at the peak power is larger from dawn to post‐noon, maximized near the magnetic equator, and decreases with increasing |MLAT| The frequency at the peak power increases with the amplitude for each specific magnetic local time or |MLAT|

The purpose of this study was to control the effects of different tillage and straw returning methods on the temporal and spatial changes of soil moisture, photosynthetic characteristics of maize leaves, maize yield and water use efficiency, and to provide the basis for the cultivation mode of maize yield increase, water efficiency and soil sustainable utilization in semi-humid area. The spatial and temporal changes of soil moisture, leaf photosynthetic characteristics, maize yield and water use efficiency (WUE) were studied under four treatments, rotary cultivation and ridging of straws (CK), full amount and deep turning of straw back to the field (SP), no till straw smashed in full amount, covering and returning to the field (SC) and straw mulching and mechanical deep loosening (SS). The spatial and temporal dynamics of soil water storage showed a single peak curve in 2018 and a double peak curve in 2019. Soil water storage increased with the increase of soil depth. The soil water storage of SC and SS treatments were significantly higher than that of SP and CK treatments in the range of 0–60 cm. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci) and transpiration rate (Tr) of maize leaves of SP, SC and SS treatments were significantly increased compared with CK treatment in 2018 and 2019, the Pn, Gs, Ciand Trof SP and SC treatments were significantly lower than those of SS treatment. The stomatal limitation percentage (Ls) of SS treatment was significantly decreased compared with CK, SP and SC treatments. The yield of SS treatment increased by 13.88% and 14.82% in 2018 and 2019, SP treatment increased by 7.59% and 9.12%, SC treatment increased by 7.42% and 8.5%, respectively, compared with CK treatment. The water use efficiency (WUE) of SS treatment increased by 13.89% and 9.80% in 2018 and 2019, SP treatment increased by 6.36% and 6.02%, SC treatment increased by 5.77% and 3.92%, respectively. Straw returning reduced soil water evaporation, increased soil water storage, promoted maize photosynthesis and dry matter accumulation, and significantly increased maize yield and water use efficiency. Straw mulching subsoiling is more suitable for drought resistance, yield increase and water efficient cultivation technology mode of maize in rain fed agricultural area.