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排序方式: 共有328条查询结果,搜索用时 0 毫秒
321.
Ganbaatar Tumen-Ulzii Chuanjiang Qin Dino Klotz Matthew R. Leyden Pangpang Wang Morgan Auffray Takashi Fujihara Toshinori Matsushima Jin-Wook Lee Sung-Joon Lee Yang Yang Chihaya Adachi 《Advanced materials (Deerfield Beach, Fla.)》2020,32(16):1905035
Excess/unreacted lead iodide (PbI2) has been commonly used in perovskite films for the state-of-the-art solar cell applications. However, an understanding of intrinsic degradation mechanisms of perovskite solar cells (PSCs) containing unreacted PbI2 has been still insufficient and, therefore, needs to be clarified for better operational durability. Here, it is shown that degradation of PSCs is hastened by unreacted PbI2 crystals under continuous light illumination. Unreacted PbI2 undergoes photodecomposition under illumination, resulting in the formation of lead and iodine in films. Thus, this photodecomposition of PbI2 is one of the main reasons for accelerated device degradation. Therefore, this work reveals that carefully controlling the formation of unreacted PbI2 crystals in perovskite films is very important to improve device operational stability for diverse opto-electronic applications in the future. 相似文献
322.
Molecular Orientation: Simultaneous Edge‐on to Face‐on Reorientation and 1D Alignment of Small π‐Conjugated Molecules Using Room‐Temperature Mechanical Rubbing (Adv. Funct. Mater. 19/2018)
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323.
Masakoto Kanezashi Naoya Hataoka Rana Ikram Hiroki Nagasawa Toshinori Tsuru 《American Institute of Chemical Engineers》2021,67(9):e17292
A fluorine-SiO2 membrane was prepared using triethoxyfluorosilane (TEFS) as a Si precursor, and its hydrothermal stability was evaluated. The TEFS membrane calcined at 750°C had fewer Si-OH and Si-F groups in its network structure and showed H2 permeance that was greater than 10−6 mol m−2 s−1 Pa−1 with H2/N2 and N2/SF6 permeance ratios of 10 and 210, respectively. This membrane performance was relatively stable under the temperature (< 500°C) used for steam treatment, regardless of the steam partial pressure (30, 90 kPa). On the other hand, when the steam treatment temperature was increased beyond 500°C, gas permeance decreased significantly and the membrane became highly selective for He and H2 over smaller molecules (He/N2: > 600, H2/N2: > 100). The relationship between the activation energy of H2 and the permeance ratios (He/H2, He/H2O, H2/H2O) of a TEFS-derived membrane under steam treatment higher than 600°C resulted in a network pore size that approximated in conventional microporous SiO2 membranes. 相似文献
324.
Higher‐order structural analysis of nylon‐66 nanofibers prepared by carbon dioxide laser supersonic drawing and exhibiting near‐equilibrium melting temperature
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Extended chains and/or extended chain crystals (ECC) are important structures for improving the mechanical properties of polymer fibers. ECC have so far been produced using specially prepared materials or manufacturing methods. In our study on the production of nanofibers by carbon dioxide (CO2) laser supersonic drawing, we succeeded in producing nylon‐66 nanofibers having a high melting point near the equilibrium melting point (Tm0). Two melting points (Tm) of 260 and 276°C were observed for the nanofibers, with the latter temperature being close to the Tm0 (280°C) of nylon‐66. A nanofiber that was heat treated at 279°C for 10 min displayed a large stacked lamellar structure with an average crystal thickness of 140 nm. That value was close to the average molecular chain length of 212 nm, which was calculated from the average molecular weight of the nanofibers. It was inferred from these results that ECC corresponding to the average molecular chain length were present in the nanofibers. The CO2 laser supersonic drawing process is applicable to general purpose thermoplastic polymers and uses a simple drawing system. It is expected that this drawing method will help to improve the fundamental performance of general purpose polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40361. 相似文献
325.
用质量比为5∶3的聚醚和甲苯二异氰酸酯反应,制备出聚氨酯软质泡沫.并用此材料作为高分子粘结剂,在聚氨酯发泡过程中加入高性能吸水树脂和缓释化肥,得到一种保水保肥的功能复合材料.研究了聚氨酯软质泡沫材料的配方、吸水树脂和缓释化肥加入量及加入到聚氨酯泡沫的时间对复合材料的形貌、吸水率、保水率的影响.通过栽培实验证明该复合材料能够有效地保水保肥和缓释化肥,具有良好的应用前景. 相似文献
326.
327.
Masaru Kato Toshihiro Kamada Mayura Mochizuki Toshinori Sasaki Yuko Fukushima Takumi Sugiyama Aiko Hiromasa Takashi Suda Takeo Imai 《Journal of the Institute of Brewing》2021,127(1):27-40
Low malt beers have high sales volumes in Japan, but improving their mouthfeel, including softness, smoothness and decreasing astringency, is challenging because the compounds responsible remain unclear. In this study, beer was fractionated by preparative size‐exclusion chromatography, with the polypeptide and maltodextrin fractions purified using solid‐phase extraction and ion‐exchange resin. Sensory data from a spike test showed that the mouthfeel (softness, smoothness, and reduced astringency) of low malt beer was improved both by the degree of polymerisation (DP) of maltodextrins (DP of 2‐10; at increased concentration of 40 to 60%; P < 0.01) and by 10 ‐ 20 kilodalton (kDa) high molecular weight (HMW) polypeptide and 2‐3 kDa low molecular weight polypeptide fractions (at a 50% increase in concentration; P < 0.01). Furthermore, highly purified 10 to 20 kDa HMW polypeptides improved the softness and smoothness and decreased the astringency (at a 25% increase in concentration). This report is the first to provide experimental sensory data indicating that HMW polypeptides improve the mouthfeel of beer. Based on these findings, a new low malt beer was developed that showed significantly higher levels of the 10‐20 kDa HMW polypeptides with an overall improved mouthfeel. Mass spectrometric analysis of the 10 to 20 kDa proteins identified several unique foam positive proteins, including barley dimeric alpha‐amylase inhibitor‐1 and non‐specific lipid‐transfer protein 1. These 10‐20 kDa HMW proteins are likely to be responsible for the improved mouthfeel of beer. © 2020 Kirin Holdings Kabushik Kaisha Co. Ltd. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling 相似文献
328.