Film Thickness Research Articles

The graphene-on-diamond structure with Ni-catalyzed under high temperature

Graphene-on-diamond (GOD) composite structure has been attracting considerable attention due to its unique features for all carbon sp3-sp2 electronic applications. Whereby the electrical properties of diamond surface can be purposely tailored and significantly altered through transformed graphene layers. In this work, GOD composite structures were prepared by nickel (Ni)-catalyzed high-temperature rapid annealing, and were analyzed by Raman, Hall effect measurement and Transmission electron microscopy (TEM). The results show that the difference in surface conductivity of GOD composite structure is mainly related to the number of transformed graphene layers, which is mainly affected by annealing temperature, annealing time and the thickness of nickel film. Hall measurement and TEM results demonstrate that when the transformed graphene grows graphite with a lot of Ni atoms embedded into diamond, the surface carriers of GOD composite structure are electrons. On the contrary, the surface carriers are holes while the transformed graphene contains about 3 or 5 layers. These findings may provide a route for GOD structure to become a strong candidate for next generation complementary diamond electronic devices.

Novel Mn and Si alloyed complex phase steel for automotive applications

Automotive industries require materials with higher strength, plasticity and crashworthiness, aiming for 3rd generation of advanced high strength steels (AHSS) with medium Mn, Si and minor alloying elements. In this investigation, 3rd generation AHSS were synthesized using a vacuum arc melting furnace with manganese (Mn) and silicon (Si) as major alloying elements as well as minor additions such as Cr, Al, Ni, etc. The steels thus developed were characterized using FE-SEM, XRD, microhardness tester, universal testing machine (UTM) and 3-dimensional Atom Probe Tomography (APT). The alloy steels after casting and homogenization were subjected to hot rolling at 1100 °C, with rolling exit temperature 900 ± 50 °C. The FE-SEM micrographs in SE mode revealed a complex phase microstructure with martensite, ferrite, bainitic ferrite and retained austenite in the specimens obtained after rolling and air cooling. The microhardness of the developed alloys is found in the range of 395–502 VHN in the hot-rolled and air cooled condition of the specimen. The tensile strength of alloys was measured to be in the range of 1412–1614 MPa with elongation of 12.12 %–18.92 %. The analysis of fracture surfaces after tensile tests for developed alloys revealed that Alloy 1 (Fe-4Mn-1.5Si) had dimples indicating ductile fracture while Alloy 2 (Fe-6Mn-1.5Si) has a mixture of dimples and facets, and Alloy 3 (Fe-8Mn-1.5Si) has lower dimples but larger facets, confirming quasi-ductile fracture with a lower ductility limit of 12.12 %. Atom Probe Tomography was performed to study the complex phase structure at nanoscale through re-distribution of carbon and other alloying elements. 3D APT revealed the presence of very fine retained austenite film of thickness ∼4–5 nm and carbon content of 6–8 at.%. This complex phase microstructure obtained after hot rolling and normalizing is made of very fine bainitic ferrite with film type retained austenite providing TRIP effect, in addition martensite and ferrite resulting in high strength.

Measurement of slip length and friction reduction: An experimental study about boundary slip using omniphobic and 2D coatings

There is an intrinsic link between boundary slip and superlubricity. However, due to limitations in experimental techniques, the slip length cannot be precisely measured, leaving the mechanism of boundary slip controversial. This paper aims to accurately measure the slip length at the solid-liquid interface under oil-lubricated elastohydrodynamic lubrication (EHL) conditions using experimental methods, and to explore the friction reduction due to boundary slip. The study reveals that both omniphobic (lotus leaf essence) coatings and two-dimensional (2D) material (MoS2) coatings facilitate boundary slip. The slip length measurement method proposed in this study builds a bridge between oil film thickness and slip length, successfully addressing a key issue in boundary slip research. The findings confirm the significant friction reduction due to boundary slip, representing a major advancement in reducing friction in oil-lubricated EHL contacts through boundary slip. Future research should focus on searching for coating materials with a slip length on the micrometer scale so that superlubricity could be achieved.

Antibacterial and Healing Efficacy of Mangiferin-Loaded Silver Nanoparticle and Chitosan-Alginate Membrane Dressings

Mangiferin, a bioactive constituent of Mangifera indica (family Anacardiaceae), has an impressive therapeutic profile, having antioxidant, anti-inflammatory, analgesic, antibacterial, and immunomodulatory properties capable of possessing wound healing potential. Our investigation aims to isolate and characterize mangiferin, green synthesis of silver nanoparticles (Ag-NPs) and production of chitosan alginate (Cs/Alg) film dressing loaded with mangiferin Ag-NPs and assess antibacterial and wound-healing properties against infected excision and burn wounds. The isolated mangiferin was authenticated by estimating melting point, thin layer chromatography (TLC), fourier-transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC). Ag-NPs were green synthesized and characterized by UV-visible, particle size, zeta potential (ZP), entrapment efficiency (%EE), scanning electron microscope (SEM), transmission electron microscope (TEM), and stability study. Chitosan alginate membrane dressing was prepared by incorporating mangiferin Ag-NPs, and film thickness, pH, film weight, water intake capacity, and in-vitro drug release parameters were estimated. Among the four mangiferin Ag-NP batches, MN3 formed stable polydispersity spherical Ag-NPs with smaller particle size and high %EE. Mangiferin-loaded Cs/Alg film MN-CM4 showed significantly higher (p < 0.001) drug content, wettability, release profile, and favorable pH changes. The mangiferin Ag-NPs embedded Cs/Alg film dressing showed a significantly high antimicrobial effect against the gram-positive bacterial strain of S. aureus, commonly found in wounds. MN3 and MN-CM4 treatment showed the shortest epithelialization period and enhanced wound closure. The hydroxyproline content has significantly (p < 0.001) increased, and myeloperoxidase content was reduced by MN3 and MN-CM4 treatment. MN-CM4 treatment showed complete re-epithelialization reduced inflammatory cells with thicker and denser collagen fiber deposition. The effectiveness of the Cs/Alg film of mangiferin Ag-NPs dressing has a synergistic effect on promoting speedy wound healing. The Cs/Alg film of mangiferin Ag-NPs showed rapid wound healing against infected and burned wounds, enhanced collagen synthesis, and anti-inflammatory and antibacterial efficacy.

Bi-level optimization and integrated multiple-criteria decision making under uncertainty for structural design of insulated bearings

To address the premature failure of insulated bearings, this article proposes a design method for the structure of bearings to prolong their service life. First, a bi-level optimization model is established to determine the structural parameters of bearings considering their insulating and mechanical properties. Upper-level problems include bearing voltage ratio, porosity of insulating coatings, minimum thickness of oil film and Hertz contact area. Lower-level problems include fatigue life of bearings and adhesion of insulating coatings. Second, a non-dominated sorting genetic algorithm-III based on space decomposition and penalty-based boundary intersection (NSGA-III-SD-PBI) is designed to solve the optimization model. Third, the integrated multiple-criteria decision-making (MCDM) using the fuzzy best–worst method (BWM) and fuzzy technique for order preference by similarity to an ideal solution (TOPSIS) is developed to determine the best structural parameters of bearings. A case study demonstrates the effectiveness and superiority of the proposed method, with fatigue life increased by 20%.

Preparation of Mouth Dissolving Sublingual Film of Fixed Dose Combination of Hydrochlorothiazide and Losartan Potassium and Statistical Optimization of Film.

Fast-dissolving films (FDFs) are innovative dosage forms offering advantages such as improved patient compliance, rapid onset of action, precise dosing, and favorable taste. Particularly beneficial for patients unable to swallow or require immediate drug absorption, FDFs dissolve rapidly in the mouth, releasing medication directly into the oral cavity. The sublingual application enhances drug delivery due to the high permeability of the sublingual mucosa, bypassing hepatic first-pass metabolism. This route is advantageous for drugs like losartan potassium (LP) and hydrochlorothiazide (HCZ), which benefit from enhanced bioavailability and faster onset of action. Preformulation studies included UV spectroscopy for λmax determination (LP: 282 nm, HCZ: 250 nm), DSC for thermal analysis (LP: 289.11°C, HCZ: 104.76°C), and solubility studies confirming LP’s solubility in acidic pH and HCZ’s increased solubility in pH 6.7 buffer. Compatibility studies using FTIR and DSC validated stability with excipients. Formulation optimization with HPMC E15 resulted in films with characteristics like film weight (145.66–167.0 mg), thickness (0.246–0.326 mm), folding endurance (898.0–1274.0), pH (6.0–6.70), disintegration time (77.66–174.6 s), tensile strength (77.04–141.90 g/cm²), and drug release profiles (LP: 68.78–96.22%, HCZ: 59.49–95.43% at 21 minutes). In summary, this study successfully developed LP and HCZ FDFs with optimized characteristics, demonstrating their potential in hypertension management and improving therapeutic outcomes.

In Situ Measurement of Grease Capacitive Film Thickness in Bearings: A Review

In Situ Measurement of Grease Capacitive Film Thickness in Bearings: A Review

A novel time-varying mesh stiffness model for orthogonal face gear drives considering EHL

Purpose This study aims to research the time-varying mesh stiffness (TVMS) model for orthogonal face gear drives considering elastohydrodynamic lubrication (EHL) and provide a theoretical basis for understanding the dynamic characteristics of face gear drives. Design/methodology/approach Considering EHL, a novel model is proposed to calculate the TVMS of orthogonal face gears using the deformation compatibility condition. First, the tooth surface equations of orthogonal face gears are derived according to the tooth surface generation principle. Then, the oil film thickness on the tooth surface of face gears is obtained by solving the governing equations of EHL. Furthermore, the proposed model is used to calculate the TVMS of face gears along the mesh cycle and is verified. Finally, the effects of module, tooth number of shaper cutter and pressure angle on mesh stiffness are analyzed. Findings The results indicate that when the contact ratio is greater than 1 and less than or equal to 2, the TVMS of face gears exhibits a phenomenon of double-single tooth alternating meshing where sudden changes occur. As the module increases, the overall mesh stiffness of face gears increases, and the magnitude of the sudden change at the moment of single-double tooth alternating meshing gradually increases. As the tooth number of shaper cutter and pressure angle increase, so does the TVMS of face gears. When the effect of oil film is considered, the calculated TVMS of face gears slightly increases overall and the increase in average oil film thickness leads to a rise in the TVMS. This study provides a theoretical basis for understanding the dynamic characteristics of face gear drives. Originality/value This study’s originality and value lie in its comprehensive approach, which includes conducting analysis based on loaded tooth contact, considering the influence of elastohydrodynamic lubrication, proposing a novel analytical–finite–element model, calculating TVMS of face gears, verifying the proposed model and analyzing the effects of typical structural parameters and oil film thickness.

Twisted hyperbolic van der Waals crystals for chip-scale full Stokes mid-infrared polarization detection

Abstract Investigating the polarization properties of light in the mid-infrared (mid-IR) spectrum is crucial for molecular sensing, biomedical diagnostics, and IR imaging system technologies. Traditional methods, limited by bulky size and complicated fabrication process, utilize large rotating optics for full Stokes polarization detection, impeding miniaturization and accuracy. Naturally occurring hyperbolic van der Waals (vdW) material based devices can address these challenges due to their lithography-free fabrication, ease of integration with chip-scale platforms and room-temperature operation. This study designs a chip-integrated polarimeter by performing multi-objective optimization for efficient exploration of the design parameter space. The spatial division measurement scheme used incorporates six precisely designed linear and circular polarization filters, achieving high extinction ratios exceeding 30 dB and transmittance surpassing 50%, with fabrication tolerance of film thickness up to 100 nm. The proposed device represents a significant advancement in polarimetric detection, providing a compact, cost-effective solution and opens new avenues for on-chip mid-IR polarimetric detection in next-generation ultra-compact optical systems.

Integration of PZT thick films on additively manufactured substrates for vibrational energy harvesting applications

Integration of PZT thick films on additively manufactured substrates for vibrational energy harvesting applications

Hydrothermal synthesis of nanostructured Zn2SnO4 ternary metal oxide semiconductor for toxic gas sensing application and its characterization study

Purpose The study aims to develop an inexpensive metal oxide semiconductor gas sensor with high sensitivity, excellent selectivity for a specific gas and rapid response time. Design/methodology/approach This study synthesized Zn2SnO4 nanostructures using a hydrothermal method with a 1 M concentration of zinc chloride (ZnCl2) as the zinc source and a 0.7 M concentration of tin chloride (SnCl4) as the tin source. Thick films of nanostructured Zn2SnO4 were then produced using screen printing. The structural properties of Zn2SnO4 were confirmed using X-ray diffraction, and the formation of Zn2SnO4 nanoparticles was verified by transmission electron microscopy. Scanning electron microscopy was used to analyse the surface morphology of the fabricated material, while energy dispersive spectroscopy provided insight into the chemical composition of the thick film. These fabricated thick films underwent testing for various hazardous gases, including nitrogen dioxide, ammonia, hydrogen sulphide (H2S), ethanol and methanol. Findings The nanostructured Zn2SnO4 thick film sensor demonstrates a notable sensitivity to H2S gas at a concentration of 500 ppm when operated at 160°C. Its selectivity, response time and recovery time were assessed and documented. Research limitations/implications The primary limitations of this research on metal oxide semiconductor gas sensors include poor selectivity to specific gases, limited durability and challenges in achieving detection at room temperature. Practical implications The nanostructured Zn2SnO4 thick film sensor demonstrates a strong response to H2S gas, making it a promising candidate for commercial production. The detection of H2S is crucial in various sectors, including industries and sewage plants, where monitoring this gas is essential. Social implications Currently, heightened global apprehension about atmospheric pollution stems from the existence of perilous toxic and flammable gases. This underscores the imperative need for monitoring such gases. Toxic and flammable gases are frequently encountered in both residential and industrial environments, posing substantial hazards to human health. Noteworthy accidents involving flammable gases have occurred in recent years. It is crucial to comprehend the presence and composition of these gases in the surroundings for precise detection, measurement and control. Thus, there has been a significant push for extensive research and development in diverse sensor technologies using various materials and methodologies to monitor and regulate these gases effectively. Originality/value In this research, Zn2SnO4 nanostructures were synthesized using a hydrothermal method with ZnCl2 at a concentration of 1 M for zinc and SnCl4 at a concentration of 0.7 M for tin. Thick films of nanostructured Zn2SnO4 were then fabricated via screen printing technique. Following fabrication, all thick films were subjected to testing with various toxic gases, and the results were compared to previously published data. The analysis indicated that the nanostructured Zn2SnO4 thick film sensor demonstrated outstanding performance concerning gas response, gas concentration, selectivity and response time, particularly towards H2S gas.

Analysis of Relationship between Microwave Magnetic Properties and Magnetic Structure of Permalloy Films

Changes in the microwave permeability of permalloy films with an increase in the film thickness are studied. Measurement data on the evolution of microwave permeability with film thickness are analyzed in the framework of a model for the film with a regular stripe domain structure and out-of-plane magnetic anisotropy. A correlation between the microwave magnetic properties and magnetic structure of permalloy films is established. It is demonstrated that the observed decrease in the ferromagnetic resonance frequency and the static permeability with a growth in the film thickness can ascribed to the appearance of perpendicular anisotropy and the formation of a stripe domain structure. The calculated dependences of the ferromagnetic resonance frequency and static permeability on the film thickness are in reasonable agreement with the measurement results. Based on the analysis of these dependences, the domain width in the permalloy films is estimated. It is found that for thick permalloy films, the domain width is of the order of the film thickness. The results obtained may be useful for high-frequency applications of soft magnetic films.

Thin Liquid Film View and Shear Stress During the Sliding of Air Bubbles on Tilted Plates.

The challenge when studying the impact and sliding of free-rising air bubbles on tilted surfaces is an experimental limitation in obtaining the film thickness of thin liquid film (TLF) during the bubbles' sliding on tilted surfaces. In this work, spatiotemporal evolution in the film thickness of the moving TLF between a sliding air bubble and a tilted plate was monitored by using a two-wavelength synchronized reflection interferometry microscopy (SRIM) technique. The evolution of the film thickness was directly determined from a timed series of monochromatic interference fringes recorded simultaneously at two different wavelengths. From the film thickness profile, a shear stress map at a given time was determined at different bubble sizes and inclination angles. Results showed that the film thickness of TLFs during the bubbles' sliding on tilted surfaces was in the range of 300-1200 nm, depending on bubble size and tilting angles. Sliding of air bubbles on tilted plates over a thin gap with a few hundred nanometers thickness yielded shear stress in the order of 10-50 Pa. Both the larger bubble size and higher tilting angles yielded a higher shear stress. Experimental results were quantitatively compared to numerical results obtained using the Reynolds lubrication theory. A good match between the two results was achieved. Numerical results suggested that a maximum shear stress exerted on a tilted plate occurred at a 25° tilting angle. This is the first time that the spatiotemporal evolution of TLF during bubbles' sliding on tilted surfaces has been achieved, and the shear stress exerted on the tilted surface has been directly determined.

Full-size experimental investigations on planetary gear journal bearings in high-power wind turbines

Abstract To satisfy the large-scale and high-power demands of wind turbines, planetary gear journal bearings (PGJBs) have been applied in large wind turbine gearboxes (WTGs), as an alternative to traditional rolling bearings, due to their higher reliability and smaller size. To simulate the actual lubrication behaviors of PGJBs and investigate their hydrodynamic performance, a full-size test rig for PGJBs was built in this paper. A multi-parameter detection system coupled with the ultrasonic testing method was developed. Four ultrasonic piezoelectric elements, eight thermistors, two pressure transducers, and one torque sensor were used to obtain the film thickness, oil temperature, oil pressure, and friction torque data of the test PGJB. The rated condition experiment was conducted to investigate the variation of measured lubrication performance with the operating time. Three-dimensional predictions of oil film pressure, temperature, and thickness were presented to analyze the steady-state lubrication characteristic at the rated condition. Moreover, a series of steady-state experiments were also carried out to simulate the normal operations of the test PGJB at different conditions. And the measured results were verified by the numerical predictions. The influence of rotational speed, input load, oil supply temperature, and oil supply flow on the hydrodynamic performance of the test PGJB were explored.

Numerical analysis of the Thermal EHL line contact problem under intermittent motion

Abstract A mathematical model of time-varying thermal elastohydrodynamic lubrication (EHL) is developed using a sleeve chain as the object of study. The effects of thermal effect, load, speed, rest time and equivalent radius of curvature on its EHL are investigated using theoretical simulations. The results show that during intermittent motion, a portion of oil is entrapped in the contact zone at the end of the deceleration phase, after which this entrapped oil gradually moves out of the contact zone with the onset of speed, and a lower film of oil at the lubrication inlet passes through the center of the contact zone. In simple sliding intermittent motion, the temperature rise plays a crucial role in the variation of the oil film, particularly during the motion phases, and is an unavoidable factor. An increase in stop time reduces the film thickness and increases the following friction coefficient in the acceleration stage. An increase in the equivalent radius of curvature increases the film thickness and thermal rise in the contact zone as well as decreases the friction coefficient. Since the sleeve chain is one of the most commonly used mechanism in industry, high priority should be given to the lubrication design of this structure.

Realization and optimization of the gold-mesoporous silica based bimodal surface plasmon resonance sensor with digital Gaussian filter

Abstract This work presented a novel biomdal surface plasmon resonance (BSPR) sensor with mesoporous silica film (MSF) and digital Gaussian filter. A modified Stöber solution growth approach was applied to prepare MSF film on the gold film. The conventional SPR sensor was coupled with a digital Gaussian filter to realize the BSPR sensor. After that, the Gaussian parameters were modified and the BSPR angular spectrum was obtained for further sensing experiments. Porosity and thickness of the MSF film were measured and calculated by means of a combination of simulation and measurement. The simulation results indicate that the refractive index (RI) sensitivity of the BSPR sensor could reach 75.11 deg/RIU which is 66.91% higher than the 45 deg/RIU of the conventional gold-MSF SPR sensor. Based on the experiments, the RI resolution of BSPR sensor was improved by 37.1% to 6.61 × 10−6 RIU, the limit of detection (LOD) for glucose was raised from 320 mg l−1 to 131 mg l−1, and the LOD for CTAB molecule was raised from 124.98 nM to 63.78 nM when compared to the gold-MSF SPR sensor.

Simulation of quantum states in solid-state ferromagnetic nanostructures

Purpose of the article. Identification and analysis of mathematical expressions for the energy spectrum of charge carriers in nano-sized magnetic films of nickel and Ni-Cu (substrate), as well as NiO-Ni-Cu (substrate) structures.Methods. In this work, based on basic quantum mechanical concepts and taking into account the boundary conditions for coupled quantum wells, expressions for the energy spectrum of electrons are obtained. The ferrimagnetic properties of nickel are taken into account through the effective mass value. The solution of nonlinear equations that determine discrete energy levels was achieved by numerical methods using the Mathcad mathematical package.Results. Transcendental expressions for the energies of free charge carriers in quantum wells of ferromagnetic nickel films are obtained, and the influence of the position of nickel on the copper substrate is shown. It has been shown that the use of a copper substrate leads to an increase in the density of energy levels in the nickel nanofilm. The influence of the oxide layer on single-electron states in nanofilms of nickel and its oxide is considered within the framework of the Anderson model. Based on the numerical solution of the transcendental equations obtained in the work, the influence of the ratio of the thicknesses of a ferromagnetic metal and its oxide on the energy levels of electrons localized in the oxide layer is shown.Conclusions. The formulas presented in the work for the energy spectrum take into account the energy relief of a complex quantum well, the dimensions of the film, surface oxide, and the significant effective mass in the region of the ferromagnetic film. It has been shown that an increase in the effective mass in magnetic heterostructures leads to an increase in the electron density of states. It was found that the density of electronic states in the region of surface nickel oxide is practically independent of the thickness of the nickel film. The results and conclusions of the work can be used for theoretical prediction of the physical properties of magnetic nanostructures, in particular spintronic elements.

Coupled Discrete Phase and Eulerian Wall Film Models for Drug Deposition Efficacy Analysis in Human Respiratory Airways.

The current study explores the effectiveness of drug particle deposition into human respiratory airways to cure various pulmonary-bound ailments. It has been assumed that drug solutions are inhaled in the form of tiny droplets or mist, which after striking create a thin layer along the inner surface of airways where the virus initially resides to infect the human body. A coupled Eulerian wall film (EWF) and discrete phase model (DPM) based simulation approach is used to capture these dynamics. Here, the Lagrangian DPM technique tracks the dynamics of tiny droplets, while the liquid layer formation after striking is captured using the Eulerian thin film approximations or the EWF model. Previous studies in this field primarily employed only the DPM method, which is inadequate to predict the poststriking dynamics of drug layer deposition and their spread to neutralize the respiratory virus. The drug delivery effectiveness is characterized by three different particle sizes, 1, 5, and 10 μm at the inhalation rates of 15, 30, and 60 L per minute (LPM). It has been found that the size of the drug particles significantly influences drug delivery effectiveness. The film thickness increases monotonically with particle sizes and inhalation rates. However, this increase in averaged film thickness is prominent in the range 5 to 10 μm (≈60%) compared to 1 to 5 μm (≈10%) droplet sizes at generation level 4 (G4). The other deposition parameters, e.g., deposition fraction, deposition density, and area coverage) roughly show similar behavior with the increase in droplet sizes. Therefore, it is recommended to vary the droplet sizes between 5 and 10 μm for better deposition effectiveness. The sizes of more than 10 μm mostly stuck into the oral cavity and cannot reach the targeted generations. In contrast, less than 5 μm may reach much deeper generations than the targeted one.

Effects of mulch films with different thicknesses on the microbial community of tobacco rhizosphere soil in Yunnan laterite.

The mulch film (MF) management model of the agricultural field affects the physical and chemical properties of soil (PCPS) and the structure of the microorganism community; however, studies on the relationship between the rhizosphere microorganism community structure and the thickness of MF are still limited. To understand the interactions among the MF thickness, PCPS, and rhizosphere microorganism, a study was conducted by using an integrated metagenomic strategy, where tobacco rhizosphere soil was treated with four commonly representative and used thicknesses of MFs (0.004, 0.006, 0.008, and 0.010 mm) in Yunnan laterite. The results showed that agronomic traits such as the tobacco plant height (TPH), leaf number (LN), fresh leaf weight (FLW), and dry leaf weight (DLW) were significantly (p < 0.01) improved in the field mulched with the thickest film (0.010 mm) compared with the exposed field (CK), and there was a 6.81 and 5.54% increase in the FLW and TPH, separately. The correlation analyses revealed a significant positive correlation of the MF thickness with the soil water content (SWC), soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), and available phosphorus (AP; all p < 0.01), while the MF thickness was negatively correlated with the soil temperature (ST; p < 0.01). In addition, the community structure of the rhizosphere soil bacteria was significantly changed overall by the MF thickness, which also interfered with the function of the rhizosphere soil bacteria. The correlation analyses also showed that the abundance of Bradyrhizobium and Nitrospira was positively correlated with the MF thickness, while the abundance of Sphinsinomonas and Massilia was negatively correlated with it. This indicated that with the increase of the MF thickness, the ability of the rhizosphere soil to utilize N and remove harmful molecules was strengthened, while the capacity of the rhizosphere soil to degrade pollutants was greatly reduced. These findings provide additional insights into the potential risks of the application of different thicknesses of MFs, particularly concerning the PCPS and soil microbial communities.

Analysis and Prospects of Lubrication and Friction Characteristics in Cold Strip Rolling: A Review

Lubrication and friction are the core processes in cold strip rolling, which are the key links to realizing the stable production of high‐quality strips, reflecting country advanced level in rolling technology. This review investigates the crucial properties of lubrication and friction in cold strip rolling by analyzing the mechanism, characterization methods, and influencing factors. The lubricant forms an oil film on the surface of rolls and strips based on the lubrication dynamics and tribology theory, changing the asperity contact state in the loaded roll gap, leading to changes in friction characteristics. Oil film thickness and coefficient of friction (COF) are crucial parameters for characterizing and judging the characteristics of lubrication and friction, theoretical calculations have become the core analytical method, and the study of the measurement method is still a great challenge. Parameters like rolling speed and oil viscosity affect the lubricant distribution and asperity contact in the loaded roll gap, changing the lubrication and friction state. The influence of parameters is strongly linked to the experimental or rolling environment. Prospective research trends on lubrication and friction in cold strip rolling are presented based on the status of research on lubrication and friction characterization.