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961.
Estimation of the biobased carbon content of polypropylene resin in composites on the basis of the carbon 14 concentration 下载免费PDF全文
The aim of this study was to estimate a procedure for the biobased carbon content of polypropylene (PP) resin isolated from composites containing additives or fillers on the basis of the carbon 14 concentration ratio, as measured by accelerated mass spectrometry (AMS). To reliably estimate the biobased carbon content of plastics, additives and fillers in the composites had to be removed because they often contain significant amounts of biobased carbon. To obtain specimens with purity suitable for estimation, an isolation procedure for PP from the composites was devised. The dissolution of the composites in 1,2,3,4‐tetrahydronaphthalene at 150°C, followed by immediate centrifugation of the hot solution, yielded PP as semicrystalline precipitates by allowing the hot solution to cool during centrifugation. The recovery of the resin through the scooping off of the precipitates was typically 90%. This simple procedure provided a suitable specimen for the estimation of biobased carbon content by AMS on the basis of ASTM D 6866. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39978. 相似文献
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964.
Civic Technology and Community Building: Interaction Effects Between Integrated Connectedness to a Storytelling Network (ICSN) and Internet and Mobile Uses on Civic Participation 下载免费PDF全文
This study draws on communication infrastructure theory (CIT) to examine the extent to which expressive uses of Internet and mobile devices moderate the relationship between integrated connectedness to a storytelling network (ICSN) and offline and online civic participation. Data collected through a Web survey of a U.S. national online panel (N = 1201) reveal that the relationships of ICSN with offline and online civic participation are conditioned by locality‐oriented expressive uses of Internet and mobile media. With these findings, this study discusses theoretical insights, policy implications, and practical applications. 相似文献
965.
Identification of Chimeric αβγ Diterpene Synthases Possessing both Type II Terpene Cyclase and Prenyltransferase Activities 下载免费PDF全文
Takaaki Mitsuhashi Dr. Masahiro Okada Prof. Dr. Ikuro Abe 《Chembiochem : a European journal of chemical biology》2017,18(21):2104-2109
Two unusual diterpene synthases composed of three domains (α, β, and γ) were identified from fungal Penicillium species. They are the first enzymes found to possess both type II terpene cyclase (TC) and prenyltransferase (PT) activities. These enzymes were characterized by heterologous expression in Aspergillus oryzae and in vitro experiments with wild-type, mutated, and truncated enzymes. The results revealed that the α domain in the C-terminal region of these enzymes was responsible for the PT activity, whereas the βγ domains in the N-terminal region composed the type II TC, and formed copalyl diphosphate ( 2 ). Additionally, between the α and βγ domains, there is a characteristic linker region, in which minimal secondary structure is predicted. This linker does not exist in the characterized three-domain (αβγ) terpene synthases known as monofunctional type I or type II TCs, or bifunctional type I and type II TC enzymes. Therefore, both the catalytic activities and protein architecture substantially differentiate these new enzymes from the previously characterized terpene synthases. 相似文献
966.
Tetsuya Hama Masaaki YokoyamaAkihiro Yabushita Masahiro KawasakiNaoki Watanabe 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(9):1011-1015
Water ice is the major solid component in a variety of astrophysical environments, e.g., cold and dense molecular clouds. Photodesorption plays a dominant role in consuming ice in such cold regions. In this study, photodesorption of vibrationally ground-state H2O(v = 0) from amorphous solid water has been investigated at 157 nm. Using a resonance-enhanced multiphoton ionization technique, the translational and rotational energy distributions of photodesorbed H2O(v = 0) were measured, i.e., Boltzmann distributions at 1800 and 300 K, respectively. These energies are in good accordance with those predicted by classical molecular calculations for water photodesorption due to a kick-out mechanism following absorption of a single photon; hot H atom released by photodissociation of H2O in ice transfers enough momentum to another H2O molecule to kick it off the surface. Desorption of D2O(v = 0) following 193 nm photoirradiation of a D2O/H2S mixed ice was investigated to provide further direct evidence for the operation of a kick-out mechanism. The other desorption mechanisms were also discussed in the context of possible photodesorption of vibrationally excited H2O. 相似文献
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968.
Akihiro Kabasawa Jumpei Saito Kenji Miyatake Hiroyuki Uchida Masahiro Watanabe 《Electrochimica acta》2009,54(3):1076-598
A novel sulfonated polyimide membrane containing triazole groups (SPI-8) was subjected to long-term fuel cell operation. Excellent durability of the SPI-8 membrane was confirmed by single cell operation for 5000 h at 80 °C. Open circuit voltage and hydrogen crossover through the membrane showed only minor changes during cell operation, indicating a lack of catastrophic damage for the SPI-8 membrane. It was found by post-test analyses of the membrane that the ion exchange capacity (IEC) decreased only slightly, but the molecular weight decreased to 1/10, resulting in a loss of mechanical strength. It was concluded that the major degradation mode of the sulfonated polyimide membrane involves the ring-opening of the imide linkages via hydrolysis, while a certain degree of side chain degradation occurs as a result of oxidative attack by radical species. 相似文献
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970.
Takashi Muramatsu Sadamitsu Hashimoto Yoshiyuki Shibukawa Kazuhiro Yuasa Masahiro Furusawa Masaki Shimono 《Microscopy research and technique》2013,76(10):988-991
Gap junctions play an important role in differentiation of odontoblasts. Gap junction protein, connexin 43 is expressed in odontoblast. However, the detailed localization in odontoblasts has yet to be fully investigated. We investigated the localization of connexin43 in rat odontoblasts immuno‐electron microscopically. The rats were transcardially fixed with 1% paraformaldehyde in 0.1M phosphate buffer, and mandibles were decalcified with 10% ethylenediamine tetraacetic acid. Pre‐embedding method was carried out for immuno‐electron microscopic analysis. Microscopically, gap junctions were localized between bodies of odontoblasts, and between bodies and processes of odontoblasts. The gap junctions were labeled with gold particles that indicated connexin43. These results suggest that gap junctions between odontoblasts are definitely composed of connexin43 in rats, and our methods used in this study is useful to investigate localization of connexin43 immuno‐electron microscopically. Microsc. Res. Tech., 76:988–991, 2013. © 2013 Wiley Periodicals, Inc. 相似文献