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In order to study the change rules of mineral composition, micro-structure evolution characteristics and their relationship with dynamic properties of granite after high temperature treatment, the high temperature tests on Beishan granite in Gansu Province, China, were carried out at 20−1 000 ℃. Microscopic images of granite after high temperature treatment were obtained by slicing technique and polarizing microscope. The evolution of mineral composition, mineral content and micro-structure characteristic parameters of granite with temperature were studied through mineral composition analysis, micro-cracks characteristic identification and parameters calculation. Subsequently, dynamic impact compression tests of high temperature treated granite were carried out by split Hopkinson pressure bar (SHPB) system, to analyze the effects of temperature, impact rate and micro-structure characteristics on dynamic peak stress. On this basis, the quantitative relationship between micro-structure characteristics and macroscopic dynamic properties was established. The results show that high temperature has a significant effect on the mineral composition, micro-structure and impact compressive strength of granite, and 600 ℃ is taken as the threshold temperature. The loading rate also significantly affects the impact compressive strength, and the larger the loading rate is, the less the influence of temperature on the macroscopic dynamic properties is. The evolution process of the micro-structure of granite after high temperature treatment is the internal mechanism for the change of its macroscopic dynamic properties with temperature. The microcrack characteristics have a significant correlation with the dynamic peak stress, and the average crack width is the main factor affecting the dynamic peak stress of granite.

Revise ISO 22768∶2017 based on China′s industrial standards, and expand the scope of application to latex. The effects of sample preparation method, gas flow rate, heating rate and sample amount on the determination results of glass transition temperature were investigated, and the precision of the method was established. The results showed that, when the drying method was selected, the gas flow rate was 20 mL/min, the sample amount was 5-20 mg, and the heating rate was 20 ℃/min, the method had good precision, the standard deviation of repeatability was less than 0.30 ℃ and the standard deviation of reproducibility was less than 1.01 ℃.

All-inorganic cesium lead halide perovskite materials have potential applications in mini/micro-LED display applications due to their excellent photoelectric properties. However, these materials have an uncontrollable tendency to form large-sized crystals and poor stability, which is not conducive to miniaturized optoelectronic applications. Herein, a novel Cs4PbBr6@KBr color conversion film (Cs4PbBr6@KBr CCFs) with both excellent luminescence properties and high stability was in situ constructed by using inkjet printing technology. The improvement in performance is attributed to the reduction in perovskite defects within the structure and the isolation of oxygen and water by the surface modification layer, which is related to the higher solubility product of KBr. The Cs4PbBr6@KBr CCFs printed on a PET flexible substrate present a high-resolution dot matrix of 16.7 μm and a homogeneous and bright green emission with a high photoluminescence quantum yield of 94%. Moreover, the Cs4PbBr6@KBr CCFs retain 65% of their initial intensity after being aged at 70 °C for 16 h, which is superior to that of perovskite CCFs without the coating of KBr. These results indicate that the Cs4PbBr6@KBr composite has excellent potential in realizing mini/micro-LED displays with high resolution and anti-counterfeiting lables. [ABSTRACT FROM AUTHOR]

As a result of global warming, the thawing settlement disasters of permafrost in the Qinghai–Tibet Engineering Corridor (QTEC) have intensified, which has serious effects on the safe operation of permafrost highway engineering. In this work, a prediction model for the thawing depth of permafrost subgrade in the QTEC under the climate warming scenario was established. Based on the survey results of permafrost ice content along the QTEC and the classification of thawing settlement risks, the zoning characteristics of thawing settlement of permafrost subgrade in the QTEC were obtained and analyzed. The results showed that the thawing depth of permafrost underlying the 26 m width subgrade in the QTEC will mainly remain below 9 m, and the area with a thawing depth of 6~9 m will have the widest spread within the next 20 years. The thawing settlement will be between 0.02 m and 5.45 m, with an average value of about 0.93 m after 20 years. Furthermore, after 50 years, the thawing depth of permafrost underlying the 26 m width subgrade will almost always be greater than 9 m, and the average thawing settlement will be about 1.12 m. Within the next 20 to 50 years, the risk of permafrost subgrade thawing settlement in the QTEC will be the most significant risk type, and this effect will mainly be distributed in the Kunlun Mountains, Chumar River Plain, Kekexili Mountains, Beiluhe Basin, Tanggula Mountains and intermountain Basins. [ABSTRACT FROM AUTHOR]

The curing characteristics and tensile properties of sulfur and mercaptan modified chloroprene rubber(CR) were evaluated using carbon black free formulation were studied .The results showed that the specific surface area of magnesium oxide(MgO) affected the curing rate of CR, with the increase of the specific surface area of MgO, the curing efficiency improved. The specific surface area of MgO also effected the tensile properties of vulcanizated CR. The carbon black free formulation A and formulation B were applicable to evaluate curing characteristics and tensile properties of mercaptan modified CR, and the evaluation results may not be compareable. The carbon black free formulation was suitable for evaluating the curing characteristics and tensile properties of sulfur modified and mercaptan modified CR, and the precision of the test results could meet the requirements of ASTM D 3190—2006.

The contents of soap and organic acid in emulsion polymerized styrene-butadiene rubber determined by indicator titration and potentiometric titration in ISO 7781 were compared. The differences between the determination principles and results of the two methods were compared, and the accuracy of the results was investigated by standard addition experiment. The results showed that the results of potentiometric titration and indicator method were consistent. When testing the soap content in emulsion polymerized styrene-butadiene rubber, the indicator method was greatly affected by amine antioxidant and filling oil. But the potentiometric titration method was less affected by amine antioxidant and was not affected by filling oil, so the determination result was more accurate.