Spray Deposition Synthesis of Locally Ordered Mesoporous Polycrystalline Titania Films at Low Temperature

A low-temperature spray deposition synthesis was developed to prepare locally hexagonally ordered mesoporous titania films with polycrystalline anatase pore walls in an evaporation-induced self-assembly process. The titania film preparation procedure is conducted completely at temperatures below 50 °C. The effects of spray time, film thickness, synthesis time prior to spray deposition, and aging time at high relative humidity after deposition on the atomic arrangement and the mesoorder of the mesoporous titania were studied. We find the crystallite size to depend on both the synthesis time and aging time of the films, where longer times result in larger crystallites. Using the photocatalytic activity of titania, the structure-directing agent is removed with UV radiation at 43–46 °C. The capability of the prepared films to remove the polymer template increased with longer synthesis and aging times due to the increased crystallinity, which increases the photocatalytic efficiency of the titania films. However, with increasingly longer times, the crystallites grow too large for the mesoorder of the pores to be maintained. This work shows that a scalable spray coating method can be used to prepare locally ordered mesoporous polycrystalline titania films by judiciously tuning the synthesis parameters.

Effects of Aging on the Dry Shrinkage Cracking of Lime Soils with Different Proportions

In this study, the reasonable aging time of lime soils with different ratios was determined to investigate the effect of aging on the internal mechanism of the dry shrinkage cracking of lime soil. To this end, the effects of aging time, lime content, and particle size on the volume crack rate, expansion and shrinkage rate, particle size distribution, and pH were analyzed using a dry–wet cycle, screening, and pH tests. In addition, the changes in the particle structure of the samples and the formation of new substances were analyzed. The results revealed that the volume crack and expansion shrinkage rates of the sample initially decreased, and then stabilized with increasing aging time. In addition, the aging time of the sample increased with increasing lime content and particle size. Further, at the initial aging stage, the volume crack and expansion/shrinkage rates of the sample increased with increasing lime content and particle size. With an increase in the aging time, the pH increased and then decreased significantly to 0.57–1.1% at the reasonable aging time. These indicate that the pH exhibited a significant effect on the reasonable aging time, and this will provide useful insights for the restoration of lime soil sites.

Effect of aging treatment on corrosion behavior of Mg-4Nd-2Gd-0.5Zr alloy

The effects of aging time on corrosion behavior of Mg-4Nd-2Gd-0.5Zr alloy in 3.5% NaCl solution were investigated by microanalysis, weight loss test and electrochemical test. The results show that the corrosion rate of Mg-4Nd-2Gd-0.5Zr alloy decreases first and then increases with the extension of aging time. Aging treatment alters the grain size and the distribution of the second phases. The second phases and grain size are the key factors affecting the corrosion rate of magnesium alloy. Among the tested alloys, the T6-8 h alloy shows the lowest corrosion rate, which is mainly attributed to the continuous distribution of second phases restricting the expansion of corrosion, hence the T6-8 h alloy showed the highest corrosion resistance. The corrosion rate of T6-16 h alloy increases obviously because of the growth of the grain size and the segregation of second phases, which accelerates the corrosion progress.

Effects of Neck-Arm Restraint Suspension of Beef Carcasses on Meat Quality and Proteome of Different Muscles During Post-mortem Aging

Beef quality is the first deciding factor for consumers to consider before purchasing. The aim of this study was to evaluate the effects of suspension and aging time on beef quality. We compared the differences in pH, drip loss, cooking loss, color, shear force, myofibril fragmentation index (MFI), and electron microscope of three muscle tissues between Achilles tendon (AT) and neck-arm restraint (NR) suspensions during seven aging periods (days 0, 1, 2, 3, 7, 14, and 21) after slaughter using the carcasses of six Xinjiang brown cattle. We found that NR suspension could significantly increase the water loss rate and MFI, as well as reduce the shear force compared to AT suspension. The muscle fiber structure with NR suspension was more severely damaged. The proteomics of longissimus dorsi was checked for the post-mortem days 1, 7, and 14. We detected 50, 26, and 29 differentially expressed proteins between NR and AT suspension at post-mortem days 1, 7, and 14, respectively. These proteins were involved in metabolic and muscle structure associated pathways and contributed to a comprehensive understanding of suspension-dependent meat quality regulation by proteins in beef cattle. To conclude, NR suspension can accelerate the aging time of beef carcasses, which will reduce the cost of carcass suspension and bring more benefits in the beef industry.

Effects of Isothermal Aging on Interfacial Microstructure and Shear Properties of Sn-4.5Sb-3.5Bi-0.1Ag Soldering with ENIG and ENEPIG Substrates

Sn–Sb system solders and ENIG/ENEPIG surface finish layers are commonly used in electronic products. To illustrate the thermal reliability evaluation of such solder joints, we studied the interfacial microstructure and shear properties of Sn-4.5Sb-3.5Bi-0.1Ag/ENIG and Sn-4.5Sb-3.5Bi-0.1Ag/ENEPIG solder joints after aging at 150 °C for 250, 500 and 1000 h. The results show that the intermetallic compound of Sn-4.5Sb-3.5Bi-0.1Ag/ENIG interface was more continuous and uniform compared with that of Sn-4.5Sb-3.5Bi-0.1Ag/ENEPIG interface after reflow. The thickness of the interfacial intermetallic compounds of the former was significantly thinner than that of the latter before and after aging. With extension of aging time, the former interface was stable, while obvious voids appeared at the interface of the latter after 500 h aging and significant fracture occurred after 1000 h aging. The shear tests proved that shear strength of solder joints decreased with increasing aging time. For the Sn-4.5Sb-3.5Bi-0.1Ag/ENEPIG joint after 1000 h aging, the fracture mode is ductile-brittle mixed type, which means fracture could occur at the solder matrix or the solder/IMC interface. For other samples of these two types of joints, ductile fracture occurred inside of the solder. The Sn-4.5Sb-3.5Bi-0.1Ag/ENIG solder joint was thermally more reliable than Sn-4.5Sb-3.5Bi-0.1Ag/ENEPIG.

Distribution and Quantification of 1,2-Propylene Glycol Enantiomers in Baijiu

Enantiomers of 1,2-Propylene glycol (1,2-PG) were investigated in 64 commercial Chinese Baijiu including soy sauce aroma-type Baijiu (SSB), strong aroma-type Baijiu (STB), and light aroma-type Baijiu (LTB), via chiral gas chromatography (β-cyclodextrin). The natural enantiomeric distribution and concentration of 1,2-PG in various baijiu were studied to evaluate whether the distribution and content of the two isomers of 1,2-PG were correlated with the aroma type and storage year. The results showed that 1,2-PG has a high enantiomeric ratio and the (S)-configuration predominated in SSB. The average S/R enantiomeric ratio of this compound in SSB was approximately 87:13 (±3.17), with an average concentration of 52.77 (±23.70) mg/L for the (S)-configuration and 8.72 (±3.63) mg/L for the (R)-enantiomer. The (R)-configuration was predominant in the STB, whereas neither (S) nor (R)-form of 1,2-PG were detected in LTB. The content of the two configurations of 1,2-PG in the JSHSJ vintage of SSB showed a wave variation, with an average S/R enantiomeric ratio of 89:11 (±1.15). The concentration of (R)-1,2-PG in XJCTJ vintage liquors showed an upward and then downward trend with aging time, with an overall downward trend, and the concentration of (S)-form showed a wavy change with an overall upward trend. Except for the LZLJ-2019 vintage where both (R) and (S)-1,2-PG were present, all other samples only existed (R)-form, and a decreasing trend of (R)-enantiomer with aging time was observed. The enantiomeric ratio of 1,2-PG might be one of the potential markers for adulteration control of Baijiu as industrial 1,2-PG usually presented in the racemic mixture. Sensory analysis revealed olfactory thresholds of 4.66 mg/L and 23.92 mg/L for the (R)- and (S)-configurations in pure water respectively. GC-O showed both enantiomers exhibited different aromatic nuances.