In recent years there has been interest in using flax fibres to produce composites because of a number of attributes, including low density, biodegradability and high mechanical properties. It was found that treatment...In recent years there has been interest in using flax fibres to produce composites because of a number of attributes, including low density, biodegradability and high mechanical properties. It was found that treatment of flax fibres may be required to improve the bond quality with a resin. These treatments also have an impact on the properties of the fibres themselves. The objective of this project was to evaluate the impact of three treatment methods on the mechanical properties of flax fibres. The three treatment methods were alkaline, enzyme and steam-heat. After treatment, flax fibres were tested in tension using a universal test machine. Results showed that tensile strength and Young's modulus of flax fibre can be enhanced significantly by the three treatment methods, compared with untreated flax fibres. Enzyme treatment was shown to be the best approach to improve mechanical properties of flax fibre than alkaline and steam-heat treatment.展开更多
在电力系统中,终端设备的信任度评估是实现访问权限分级、数据安全采集的关键技术,对于保证电网安全稳定运行具有重要意义。传统的信任度评估模型通常基于终端设备身份识别、运行状态和交互记录等直接计算信任度评分,在面临间接攻击和...在电力系统中,终端设备的信任度评估是实现访问权限分级、数据安全采集的关键技术,对于保证电网安全稳定运行具有重要意义。传统的信任度评估模型通常基于终端设备身份识别、运行状态和交互记录等直接计算信任度评分,在面临间接攻击和节点共谋时,性能较差。针对上述问题,提出一种基于自适应交互反馈的信任度评估(Adaptive Interaction Feedback based Trust evaluation,AIFTrust)机制。所提机制通过直接信任评估模块、信任推荐模块和信任聚合模块全面地度量设备的信任等级,针对电力信息系统中海量协作终端精准地评估信任度。首先,直接信任评估模块引入交互成本,并基于信任衰减策略计算恶意目标终端的直接信任评分;其次,信任推荐模块引入经验相似性,并通过二次聚类推荐相似终端以提高推荐信任度评分的可靠性;然后,信任聚合模块基于信任评分准确性自适应地聚合直接信任度评分和推荐信任度评分。在真实数据集和生成数据集上的仿真实验结果均表明,在攻击概率为30%、信任衰减率为0.05时,AIFTrust相较于基于相似度的信任评估方法SFM(Similarity FraMework)和基于客观信息熵的信任评估方法CRT(Reputation Trusted based on Cooperation)在推荐准确度上分别提高13.30%和14.81%。展开更多
Certain activator was expected to be developed to improve the free radical intermediates relative intensity, and thus to enhance the adhesion between wood fibers when fiberboard was made by laccase treated wood fibers...Certain activator was expected to be developed to improve the free radical intermediates relative intensity, and thus to enhance the adhesion between wood fibers when fiberboard was made by laccase treated wood fibers. Reactive oxygen species (ROS) was detected in laccase-catalyzed oxidation of wood powder using ESR spin trapping technique. The effects of five metal ions (Cu2+, K+, Fe2+, Mg2+, Fe3+) and EDTA on ROS relative strengths were investigated under the condition of pH 5.6 by electron spin resonance spectrometry. The result shows that Cu2+ slightly activates the free radical reaction, and Fe2+ ion has a significant inhibitive effect on the ROS relative strength in the suspension liquid. There is a marked inhibition of the ROS relative intensity when 0.5 mmol/L EDTA is used. The metal ions that enhance laccase activity may be utilized to increase physical properties of fiberboard made by laccase oxidized wood fibers.展开更多
基金the Agricultural Bioproducts Innovation Program(ABIP)of Agriculture and Agri-food Canada
文摘In recent years there has been interest in using flax fibres to produce composites because of a number of attributes, including low density, biodegradability and high mechanical properties. It was found that treatment of flax fibres may be required to improve the bond quality with a resin. These treatments also have an impact on the properties of the fibres themselves. The objective of this project was to evaluate the impact of three treatment methods on the mechanical properties of flax fibres. The three treatment methods were alkaline, enzyme and steam-heat. After treatment, flax fibres were tested in tension using a universal test machine. Results showed that tensile strength and Young's modulus of flax fibre can be enhanced significantly by the three treatment methods, compared with untreated flax fibres. Enzyme treatment was shown to be the best approach to improve mechanical properties of flax fibre than alkaline and steam-heat treatment.
文摘在电力系统中,终端设备的信任度评估是实现访问权限分级、数据安全采集的关键技术,对于保证电网安全稳定运行具有重要意义。传统的信任度评估模型通常基于终端设备身份识别、运行状态和交互记录等直接计算信任度评分,在面临间接攻击和节点共谋时,性能较差。针对上述问题,提出一种基于自适应交互反馈的信任度评估(Adaptive Interaction Feedback based Trust evaluation,AIFTrust)机制。所提机制通过直接信任评估模块、信任推荐模块和信任聚合模块全面地度量设备的信任等级,针对电力信息系统中海量协作终端精准地评估信任度。首先,直接信任评估模块引入交互成本,并基于信任衰减策略计算恶意目标终端的直接信任评分;其次,信任推荐模块引入经验相似性,并通过二次聚类推荐相似终端以提高推荐信任度评分的可靠性;然后,信任聚合模块基于信任评分准确性自适应地聚合直接信任度评分和推荐信任度评分。在真实数据集和生成数据集上的仿真实验结果均表明,在攻击概率为30%、信任衰减率为0.05时,AIFTrust相较于基于相似度的信任评估方法SFM(Similarity FraMework)和基于客观信息熵的信任评估方法CRT(Reputation Trusted based on Cooperation)在推荐准确度上分别提高13.30%和14.81%。
基金This work was supported by the National Natural Science Foundation of China (30471352).
文摘Certain activator was expected to be developed to improve the free radical intermediates relative intensity, and thus to enhance the adhesion between wood fibers when fiberboard was made by laccase treated wood fibers. Reactive oxygen species (ROS) was detected in laccase-catalyzed oxidation of wood powder using ESR spin trapping technique. The effects of five metal ions (Cu2+, K+, Fe2+, Mg2+, Fe3+) and EDTA on ROS relative strengths were investigated under the condition of pH 5.6 by electron spin resonance spectrometry. The result shows that Cu2+ slightly activates the free radical reaction, and Fe2+ ion has a significant inhibitive effect on the ROS relative strength in the suspension liquid. There is a marked inhibition of the ROS relative intensity when 0.5 mmol/L EDTA is used. The metal ions that enhance laccase activity may be utilized to increase physical properties of fiberboard made by laccase oxidized wood fibers.
