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81.
Ningqin Deng He Tian Jian Zhang Jinming Jian Fan Wu Yang Shen Yi Yang Tian-Ling Ren 《半导体学报》2021,42(8):21-33
Black phosphorus(BP),an emerging two-dimensional material,is considered a promising candidate for next-genera-tion electronic and optoelectronic devices due to in-plane anisotropy,high mobility,and direct bandgap.However,BP devices face challenges due to their limited stability,photo-response speed,and detection range.To enhance BP with powerful electric-al and optical performance,the BP heterostructures can be created.In this review,the state-of-the-art heterostructures and their electrical and optoelectronic applications based on black phosphorus are discussed.Five parts introduce the perform-ance of BP-based devices,including black phosphorus sandwich structure by hBN with better stability and higher mobility,black phosphorus homojunction by dual-gate structure for optical applications,black phosphorus heterojunction with other 2D materials for faster photo-detection,black phosphorus heterojunction integration with 3D bulk material,and BP via As-doping tunable bandgap enabling photo-detection up to 8.2 μm.Finally,we discuss the challenges and prospects for BP electric-al and optical devices and applications. 相似文献
82.
Formation of SiC whiskers/leucite-based ceramic composites from low temperature hardening geopolymer
Siqi Ma Peigang He Shengjian Zhao Hualong Yang Qikun Wang Wenjiu Duan Song Chen Xiaoming Duan Dechang Jia Yu Zhou 《Ceramics International》2021,47(13):17930-17938
In this study, SiC whiskers (SCWS) reinforced geopolymer composites (SCWS/KGP) and their ceramic products (SCWS/leucite) were prepared, and effects of SiC whiskers contents on the microstructure and flexural strength of the SCWS/KGP and SCWS/leucite composites were investigated. The results show that the whisker addition has little influence on both phase composition and thermal shrinkage of the KGP composites, but a suitable content of whisker will result in the improved flexural strength, and when the SCWS content is 2 wt%, flexural strength of the SCWS/KGP composite is enhanced by 95% compared with the neat geopolymer. The flexural strength of the composites can be further enhanced significantly after the composites being treated at 1100 °C and 1200 °C and flexural strength of the composite with SCWS content of 2 wt% was 107% and 125% higher than the untreated counterpart, respectively. The increase in flexural strength of the composites should be attributed to the strong leucite formation, whisker debonding and pulling out from matrix during the fracturing process based on the good interfacial bonding state between whisker and leucite matrix. 相似文献
83.
Zahraa Bouyahia Ahmed Mdarhri Anass Benayad Christian Brosseau Ilham Elaboudi Didier Chicot Alain Iost Delong He Jinbo Bai 《应用聚合物科学杂志》2021,138(29):50697
Carbon black (CB) filled elastomers are structurally complex materials that offer unique properties at different length scales. They have tremendous potential applications in a number of fields including the automotive and aerospace industries and for designing innovative smart materials such as artificial muscles but their applications remain limited primarily due to inadequate understanding of their unique mechanical properties. Here, using the Berkovich technique to probe the surface mechanical properties at different scales the nanoindentation response of a series of composites made by homogeneously dispersed CB nanoparticles inside a semicrystalline copolymer matrix has been explored. While the measured loading part of the force–displacement curves is well described by Meyer's empirical power relation, the inverted methodology (IM) approach to deal with the unloading part has been considered and its outcome has been compared with that obtained from the standard Oliver–Pharr's method. The results were consistent with the observed increase of hardness when the applied displacement decreases for all composite samples over a large range of CB volume fraction. Zhang and Xu's model is demonstrated to produce experimentally consistent explanation of this indentation size effect. X-ray photoelectron spectroscopy (XPS) spectra also show composition gradients with depth up to 100 nm. Furthermore, the effect of CB content, surface features, and length scale-dependent deformation on the hardness–displacement behavior have been considered. These findings highlight the possibility of attaining a diverse set of mechanical properties by a better understanding of the nanoindentation response of CB filled elastomers which can be useful for material selection and design improvements in a number of practical applications. 相似文献
84.
A Cooper(II) (Cu2+)-nitrogen coordination-crosslinked network is designed in poly(styrene-co-butadiene-co-styrene) (SBS) to change commercial elastomers into advanced soft materials. Herein, ligand groups into SBS molecular chains by the 3,6-di(2-pyridyl)-1,2,4,5-tetrazine (DPT) click reaction are first introduced. The results from fourier transform infrared (FT-IR), 1H-nuclear magnetic resonance, and X-ray photoelectron spectroscopy (XPS) are verified the successful modification of SBS. The DPT-grafted SBS could then coordinate with copper sulfate (CuSO4) to form a Cu2+-nitrogen bond, which is further characterized using FT-IR, XPS, atomic force microscope, scanning electron microscope, and geometric structure calculations. After modifying SBS to form an SBS-DPT/CuSO4 composite (SBS-DPT2-Cu10), the tensile stress is improved from 11.43 to 23.25 MPa, while the elongation at break is remained almost unchanged, and the corresponding toughness is increased from 33.21 to 63.26 MJ m–3. Moreover, the dynamic nature of the Cu2+-nitrogen coordination bonds enables the SBS-DPT/CuSO4 composite to exhibit sustained thermoplastic performance and excellent shape memory behavior under an external thermal stimulus. 相似文献
85.
Xiao-Jing Hou Liu-Ying Yu Chao-Hong He Ke-Jun Wu 《American Institute of Chemical Engineers》2022,68(2):e17408
Deep eutectic solvents (DESs) are mixtures of two or more components that have lower melting temperatures compared to their constituting components. DESs possess many advantages, for example, low volatility, low flammability, and low toxicity, which make them promising alternatives to traditional organic solvents. The melting temperature, one of the important physical properties, is of essential importance for industrial applications. In this work, a group and group-interaction contribution method was proposed to estimate the melting temperatures of DESs using an extensive database (1528 DESs, 1541 data points). The average absolute relative deviation (%AARD) between the estimated and experimental values of the melting temperature was 5.67% for binary DESs. Subsequently, this method was also extended to estimate the melting temperature of ternary DESs, with the AARD of 6.13%. The results indicate the high accuracy and broad applicability of the method and pave the way for the rational design of task-specific DESs. 相似文献
87.
为解决ε-聚赖氨酸(ε-PL)的油难溶性以及由此导致抑菌性能差的问题,选取吐温80、司盘80作为表面活性剂,无水乙醇、丙三醇作为辅助剂,制备ε-PL与低浓度表面活性剂的预混溶液,探究其植物油溶性及其对油浸面制品中腐败微生物的抑制效果。结果表明,活性剂相与水相比例为1 ∶ 1.25,1 ∶ 1.5,1 ∶ 1.75配制的预混溶液(ETSG)均无底部凝胶沉淀,外观透明,流动性好。活性剂相与水相比例为1 ∶ 1.25的1% ETSG在葵花籽油和橄榄油中均可均匀分散且外观透明。ETSG能够显著抑制霉菌菌丝生长和孢子萌发,培养5 d后,0.1% ETSG处理的链格孢霉T5A和赭曲霉9F的菌落直径显著低于对照组83.44%和45.21%,4% ETSG处理的土曲霉YS-1-1的菌落直径显著低于对照组39.64%。0.1% ETSG使链格孢霉与赭曲霉的孢子萌发率分别从87.07%和85.01%降至1.91%和1.84%,4% ETSG处理使土曲霉的孢子萌发率从90.27%降至4.16%。此外,2%的ETSG可使面筋食品中的霉菌菌落总数显著下降62.5%。本研究为ε-PL作为天然防腐杀菌剂在油浸食品中的应用提供了理论依据。 相似文献
88.
89.
Ankit Garg He Huang Weiling Cai Narala Gangadhara Reddy Peinan Chen Yifan Han Viroon Kamchoom Shubham Gaurav Hong-Hu Zhu 《岩石力学与岩土工程学报(英文版)》2021,13(3):593-602
Biochar has been used as an environment-friendly enhancer to improve the hydraulic properties(e.g.suction and water retention) of soil.However,variations in densities alter the properties of the soil-biochar mix.Such density variations are observed in agriculture(loosely compacted) and engineering(densely compacted) applications.The influence of biochar amendment on gas permeability of soil has been barely investigated,especially for soil with diffe rent densities.The maj or obj ective of this study is to investigate the water retention capacity,and gas permeability of biochar-amended soil(BAS) with different biochar contents under varying degree of compaction(DOC) conditions.In-house produced novel biochar was mixed with the soil at different amendment rates(i.e.biochar contents of 0%,5% and 10%).All BAS samples were compacted at three DOCs(65%,80% and 95%) in polyvinyl chloride(PVC)tubes.Each soil column was subjected to drying-wetting cycles,during which soil suction,water content,and gas permeability were measured.A simplified theoretical framework for estimating the void ratio of BAS was proposed.The experimental results reveal that the addition of biochar significantly decreased gas permeability k_g as compared with that of bare soil(BS).However,the addition of 5%biochar is found to be optimum in decreasing kg with an increase of DOC(i.e.k_(g,65%) k_(g,80%) k_(g,95%)) at a relatively low suction range(200 kPa) because both biochar and compaction treatment reduce the connected pores. 相似文献
90.