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| 1 | Effects of Fiber Surface Pretreatment and Composite Posttreatment on Mechanical Properties of 2D⁃Cf/Phosphate Geopolymer Matrix Composites显示文摘Geopolymers are an important class of materials with potential applications because of their heat resistance,flame resistance,environmental friendliness,and possibilities of being transformed into ceramic matrix composites at low cost.However,the low mechanical properties as well as the intrinsic brittleness limit their technological implementations,and it is necessary to enhance the mechanical properties of geopolymers by adopting various kinds of reinforcements.In this work,therefore,two⁃dimensional continuous carbon fiber(Cf)reinforced phosphate⁃based geopolymer composites(Cf/geopolymer)were prepared through ultrasonic⁃assisted impregnation method.Effects of acetone treatment and high⁃temperature treatment on the properties of Cf/geopolymer composites were studied by X⁃ray photoelectron spectroscopy(XPS),X⁃ray diffraction(XRD),and scanning electron microscopy(SEM).Results of the study proved that acetone treatment plays a key role in ameliorating the interfacial interaction between Cf and phosphate matrix,which can thus enhance the mechanical properties of Cf/geopolymer composites.The Cf/geopolymer composites prepared by acetone⁃treated Cf had a flexural strength of 156.1 MPa and an elastic modulus of 39.7 GPa in Y direction.Moreover,an additional Sol⁃SiO2 re⁃impregnation treatment could further enhance the mechanical properties of the acetone⁃treated Cf/geopolymer composites by repairing the cracks and filling the pores.The results in this paper not only provide insights into the surface modification of Cf,but also report a facile and low⁃cost preparation route for Cf/geopolymer composites with potential applications in aerospace and defense technology. | Peigang He Zhanlin Jia Shuai Fu Jiatao Wang Xiaoming Duan Zhihua Yang Dechang Jia Yu Zhou | 2020 | Journal of Harbin Institute of Technology(New Series)2020，27，3： | 0 |
| 2 | Geochronology and Geochemistry of the Early Paleozoic Ore-host Volcanic Sequence in the Kalatag Area,East Tianshan,NW China:Implications for the Tectonic Evolution显示文摘The East Tianshan contains many late Paleozoic magmatic and polymetallic deposits.Recent studies demonstrate that the early Paleozoic volcanic rocks discovered in the northern region of East Tianshan can be subdivided into the Daliugou,Hongliuxia and Kalatag formations.Here,we report zircon U-Pb ages of volcanic rocks and quartz diorite porphyry,together with whole-rock geochemical and Sr-Nd isotope data of early Paleozoic volcanic rocks,in order to investigate their petrogenesis and geodynamic setting.Zircon U-Pb analyses of the rocks suggest that the Kalatag Formation formed at ca.438-413 Ma.Geochemical characteristics of the early Paleozoic volcanic rocks exhibit typical subduction-related features.They have high Mg^(#)(44-75),positiveε_(Nd)(t)values(0.25-7.88),low^(87)Sr/^(86)Sr ratios(0.70457 to 0.70588)and young two-stage Hf isotope model ages(551-446 Ma),consistent with a depleted mantle origin with limited crustal contamination.The basaltic andesite and andesite have relatively high MgO contents(6.1-9.4 wt%),suggesting that they belong to high-magnesian andesites.They were most likely derived from the partial melting of mantle peridotite caused by the addition of fluids released by subducted oceanic slab.Based on regional geology,geochemical characteristics and previous studies,we infer that the southward subduction of the Junggar Ocean slab resulted in the generation of early Paleozoic volcanic rocks and arc setting-related metallogenic systems in the Kalatag area. | ZHANG Zhenlong YANG Fuquan ZHOU Taofa GENG Xinxia ZHANG Zhixin YANG Chengdong QIU Zhanlin | 2023 | Acta Geologica Sinica(English Edition)2023，97，5： | 0 |
| 3 | Alkaloid Dimers Isolated from Thalictrum baicalense Have Antitumor Activities显示文摘Comprehensive Summary A pair of heterodimeric isoquinoline alkaloid enantiomers,(+)thaliberberine A,five new thalifaberine-type aporphine-benzylisoquinoline(ABl)alkaloids,thalicultratines M-Q,and thirteen known analogues were isolated from the roots of Thalictrum baicalense Turcz.ex Ledeb.The structures were determined by extensive spectroscopic methods and ECD calculations.Thaliberberine A featuring a novel carbon skeleton coupled by two different classes of isoquinoline alkaloids,protoberberine and phthalidoisoquinoline,represents the first natural product with the berberine skeleton substituted at C-6.Plausible biosynthetic routes of 1 are proposed. | Jingjing Xue Yuetong Wang Fangshen Liu Hangao Yang Bin Lin Zhanlin Li Yongkui Jing Dahong Li Huiming Hua | 2022 | Chinese Journal of Chemistry2022，40，15： | 0 |
| 4 | Catalyst particle shapes and pore structure engineering for hydrodesulfurization and hydrodenitrogenation reactions显示文摘Catalyst particle shapes and pore structure engineering are crucial for alleviating internal diffusion limitations in the hydrodesulfiirization(HDS)/hydrodeni-trogenation(HDN)of gas oil.The effects of catalyst particle shapes(sphere,cylinder,trilobe,and tetralobe)and pore structures(pore diameter and porosity)on HDS/HDN performance at the particle scale are investigated via mathematical modeling.The relationship between particle shape and effectiveness factor is first established,and the specific surface areas of different catalyst particles show a positive correlation with the average HDS/HDN reaction rates.The catalyst particle shapes primarily alter the average HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor.An optimal average HDS/HDN reaction rate exists as the catalyst pore diameter and porosity increase,and this optimum value indicates a tradeoff between diffusion and reaction.In contrast to catalyst particle shapes,the catalyst pore diameter and the porosity of catalyst particles primarily alter the surface HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor.This study provides insights into the engineering of catalyst particle shapes and pore structures for improving HDS/HDN catalyst particle efficiency. | Yao Shi Zhao Li Changfeng Yang Zhanlin Yang Zhenhui Lv Chong Peng Bao-Lian Su Weikang Yuan Xinggui Zhou Xuezhi Duan | 2022 | Frontiers of Chemical Science and Engineering2022，16，6： | 0 |
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