The production of Indo-Pacific monochrome drawn glass beads in the Sasanian Empire: Insights from Xinjiang,northwest China

Indo-Pacific glass beads are produced by the drawn technique, which originates from South Asia, and their chemical compositions are unique in South and Southeast Asia. However, a small number of Indo-Pacific beads with Sassanian glass compositions are excavated in Asia and Africa after the 3rd c. CE, and their production sites in South/Southeast Asia or in the Sassanian region remain controversial. In this study, 15 drawn glass beads with various colours from Astana necropolis (ca. the 4th-8th c. CE) in Xinjiang, northwest China were investigated by using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), Scanning Electron Microscope, Raman spectroscopy and visible to near-infrared spectroscopy to characterize the production technology and origins. The results show that most Astana glass beads share similar chemical compositions with the glassware from Veh Arda?īr, a famous Sasanian site. Furthermore, Sasanian glass compositions predominate in Indo-Pacific beads in Xinjiang during the 4th-8th c. CE, while popular glass recipes in contemporary South/Southeast Asia are infrequently found; thus, it is deduced that the drawn method should have been mastered by Sasanian craftsmen. Moreover, the cobalt materials in Sasanian glass were imported from further western regions and changed over time. The popular Sasanian glass across central Eurasia reflects the trade monopoly of Sasanian in West and Central Asia, and the land glass bead trade is distinct from the contemporary maritime trade in the Indian and Pacific Oceans.     

Effect of Mo on corrosion behavior of Ni20Cr–xMo alloys in air with NaCl–KCl–CaCl2 vapor at 570°C

The effect of Mo on the corrosion behavior of Ni20Cr–xMo alloys in an oxidizing chlorine-containing atmosphere using air mixed with the salt-vapor mixture of NaCl–KCl–CaCl₂ at 570°C was investigated. The results revealed that the corrosion performance of the Ni20Cr alloys in the oxidizing chlorine atmosphere was improved by Mo addition of up to 3 wt%. The Mo-free alloy formed a potassium chromate during corrosion as a result of the reaction between the Cr₂O₃ scale and KCl vapor. The chromate formation increased the chlorine potential at the scale surface and induced the breakdown of the protective Cr₂O₃ scale, resulting in internal chromium chloride precipitates and a Cr-depleted zone. In contrast, the presence of Mo resulted in the formation of a NiO scale, which did not react with the salt vapors and, therefore, prevented the formation of chromates. The beneficial effect of Mo on the high-temperature chlorination of Ni–Cr alloys in salt-vapor-containing atmospheres was ascribed to the suppression of chlorine generation due to NiO scale formation.     

规整有机分子自聚集体对铜的高效缓蚀的研究

通过多步法合成了离子型含双苯并三氮唑环的目标分子，4，4'-{苯-1，3-二基二[(1E)-3-羰基丙-1-烯-1，3-二基]}二[2-(2H-苯并三唑-2-基)苯醇酸]二钾。在室温条件下，目标分子在3.5%（质量）NaCl/DMSO（二甲基亚枫）混合溶液 （体积比：40/60） 中能够发生分子自组装产生纳-微米级的自聚集体。通过傅里叶变换红外光谱 （FT-IR）、拉曼光谱和X射线光电子能谱 （XPS） 的表征，证实了所形成的目标分子自聚集体能够对铜表面产生强烈的化学吸附作用，在铜表面形成自组装膜。利用电化学方法测定了目标分子自聚集体吸附在铜表面形成自组装膜后，在3.5%（质量）NaCl溶液中的缓蚀性能。结果表明目标分子自聚集体在NaCl溶液中能高效地抑制铜腐蚀。     

Characterization of the structure and diffusion behavior of calcium alginate gel beads

A simple and novel method using gel shrinkage to indirectly characterize the structure of calcium alginate gel (CAG) beads during the calcium alginate gelation process was presented in this study. The effect of preparation process parameters (gelling cations, bead diameter, and alginate M _w and concentration) on the structure of the CAG bead formation process was thoroughly investigated. It was found that (a) the concentration of the Na⁺ and Ca²⁺ ion in gel bath was found to be the determining factor in the gel structure formation process by regulating the dissociation of alginate and the complexation of the calcium; (b) Na⁺ acts as a competitor with calcium and a screen in the electrostatic repulsion; (c) the effect of beads size below 700 μm on the structure of CAG beads can be neglected; and (d) the sodium alginate concentration has no significant effect on the gel formation process. Furthermore, the diffusion of bovine serum albumin (BSA) was controlled by the density of CAG bead. Consequently, a faster diffusion rate of BSA within the looser structure of beads can be observed. These results are keys to understanding the behavior and performance of beads in their utilization medium. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48923.     

Innovative method to produce large-area freestanding functional ceramic foils

Using thick and thin films instead of bulk functional materials presents tremendous advantages in the field of flexible electronics and component miniaturization. Here, a low-cost method to grow and release large-area, microscale thickness, freestanding, functional, ceramic foils is reported. It uses evaporation of sodium chloride to silicon wafer substrates as sacrificial layers, upon which functional lead titanate zirconate ceramic films are grown at 710?°C maximum temperature to validate the method. The freestanding, functional foils are then released by dissolution of the sacrificial sodium chloride in water and have the potential to be integrated into low-thermal stability printed circuits and flexible substrates. The optimization of the sodium chloride layer surface quality and bonding strength with the underlying wafer is achieved thanks to pre-annealing treatment.     

Experimental analysis of a photoreactor packed with Pd-BiVO4-Coated glass beads

A photoreactor packed with glass beads coated by palladium nanoparticles-modified BiVO₄ was tested and analyzed in phenol degradation under UV–Visible light. The photocatalytic activity of Pd-BiVO₄ under visible light is higher than TiO₂ under UV light, as we previously reported. In this work, we try to use the Pd-BiVO₄ in a large scale by coating the glass beads with it, a potentially industrial-scale use. For comparison, a flat-plate reactor and a slurry reactor were also examined. The photocatalytic activity of Pd-BiVO₄ in phenol degradation was found to be higher than that of TiO₂ in all systems (slurry, flat-plate, and packed beads reactor [PBR]). Furthermore, PBR exhibited higher energy efficiency compared to the flat-plate reactor in phenol oxidation. The superior performance of this reactor is due primarily to the highly exposed catalyst surface area, high mass transfer coefficient, and effective delivery of both photons and reactants to the catalyst surfaces. © 2018 American Institute of Chemical Engineers AIChE J, 65: 132–139, 2019