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In order to improve the tribological properties of phosphate-bonded coatings，the feasibility of modified carbon fibers in coatings was explored.In this work，graphene oxide (GO) was grafted to carbon fibers (CF) by electrophoretic deposition，and the phosphate ceramic coating was prepared by scraping-thermosetting method.Scanning electron microscopy and Raman spectroscopy were used to determine the surface morphology and molecular structure of CF-GO samples，and the influence of CF-GO content on the tribological properties of coatings was studied by friction testing machine.Results showed that the tribological properties of coatings containing CF-GO were significantly better than those containing untreated CF.With the increase of CF-GO content，the friction coefficient and wear rate of phosphate bonded coatings showed changes that decreased first and then increased.Compared with coatings without CF，the coatings containing 10%(mass fraction) CF-GO exhibited excellent tribological properties，and the corresponding average coefficient of friction and wear rate were reduced by 50%and 38%，respectively.This above indicated that the appropriate amount of CF-GO could improve the tribological properties of its coating，which could provide a good reference for the development and engineering application of new phosphate coatings.

ScAlMgO4 (SCAM), which can be used as an epitaxial substrate material of GaN in power devices, faces the challenge of achieving a high-quality surface by ultra-precision polishing due to its brittle and easily cleaved characteristics, which are closely associated with its mechanical properties. The micromechanical properties of SCAM single crystals were evaluated by nanoindentation and microscratch tests using different indenters. The elastic modulus EIT and the indentation hardness HIT of SCAM obtained by nanoindentation were 226 GPa and 12.1 GPa, respectively. Leaf-shaped chips and the associated step-like planes of SCAM can be found in the severely damaged regime during scratching by Berkovich and Vickers indenters with sharp edges due to the intersection of intense radial and lateral cracks. The fracture toughness (Kc = 1.12 MPa·m1/2) of SCAM can be obtained by using a scratch-based methodology for a spherical indenter based on linear elastic fracture mechanics (LEFM) under an appropriate range of applied loads. An optimal expression for calculating the fracture toughness of easily cleaved materials, including SCAM, via the Vickers indenter-induced cracking method using a Berkovich indenter was recommended. [ABSTRACT FROM AUTHOR]

Cigarettes with pronounced astringency can diminish consumers' enjoyment. However, due to the complex composition of cigarettes, quantifying astringency intensity accurately has been challenging. To address this, research was conducted to develop a method for assessing astringency intensity in a simulated oral environment. The astringency intensity of four cigarette brands was determined using the standard sensory evaluation method. The mainstream smoke absorbing solution (MS) was prepared by simulating the cigarette smoking process, and its physicochemical properties (such as total phenol content and pH levels) were analyzed. The lubrication properties of the five solutions were tested using the MFT‐5000 wear tester, and factors influencing cigarette astringency were examined. The findings showed that total phenol content and pH of MS were positively and negatively correlated with astringency intensity, respectively. Particularly, the lubrication properties of MS were significantly correlated with astringency intensity, and the correlation coefficient was affected by load and speed during testing. The study concluded that coefficient of friction was a more reliable measure for assessing the extent of astringency in cigarettes than the total phenol content and pH of MS, offering new insights into astringency evaluation and development of high‐grade cigarettes. [ABSTRACT FROM AUTHOR]

The viscoelastic properties of food materials will change significantly while drying is in progress, which greatly influences the food deformation caused by drying. This study aims to predict the viscoelastic mechanical behavior of Hami melon during drying using the fractional derivative model. To characterize the relaxation characteristics, based on the finite difference method, an improved Grünwald–Letnikov fractional stress relaxation model is proposed to derive an approximate discrete numerical solution of the relaxation modulus by applying the time fractional calculus. The Laplace transform method is used to verify the obtained results, and the equivalence of the two methods is proved. In addition, the stress relaxation tests prove that the fractional derivative model has a better prediction effect on the stress relaxation behavior of viscoelastic food than classical Zener model. The significant correlations between the fractional order and the stiffness coefficient and the moisture content is also studied. Which is negative correlation and positive correlation respectively. [ABSTRACT FROM AUTHOR]

Poly(N‐isopropylacrylamide) (PNIPAm) is widely implemented in responsive soft actuators. However, there are still defects of low brittleness and poor mechanical properties. Moreover, little attention has been paid to diameter shrinkage deformation of tubular PNIPAm hydrogels. In this study, physical crosslinking between Ca2+ cations and sodium alginate (SA) was introduced to form an interpenetrating network with chemically crosslinked PNIPAm, and then Ca–alginate/PNIPAm hydrogels were prepared. Molecular structure, surface morphology, swelling properties and mechanical properties were characterized. The results indicated that the pure PNIPAm hydrogel obtained using thermal initiation polymerization had better swelling and temperature‐responsive properties (with a maximum swelling ratio of 1134.65% and a fastest decrease rate of 318.45% min−1 in swelling ratio) compared to the hydrogel using ultraviolet polymerization. The mechanical properties the Ca/PNIPAm hydrogel were enhanced until the SA concentration exceeded 8 wt%. The compressive modulus of the hydrogel with SA concentration of 8 wt% (16.61 kPa) was increased by 10 times as compared with the pure PNIPAm hydrogel (1.42 kPa), and its corresponding elastic modulus increased by 47%. Moreover, a model soft actuator was prepared based on annular and tubular hydrogels. It had reversible diameter shrinkage behavior at 50 °C, and excellent temperature‐responsive property. The results reported herein provide valuable insight into the engineering application of temperature‐responsive PNIPAm‐based hydrogels. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]