An alkaline protease was applied on wool knitted fabric in an attempt to improve its shrink resistance. The influence of process parameters was evaluated and the tensile properties, surface characteristics and whitene...An alkaline protease was applied on wool knitted fabric in an attempt to improve its shrink resistance. The influence of process parameters was evaluated and the tensile properties, surface characteristics and whiteness of wool were also studied. The results showed that the action of the protease on wool was significantly enhanced by hydrogen peroxide pretreatment. Based on the preliminary test and subsequent factor analysis, an appropriate combined process was obtained. The SEM investigation of the surface characteristics demonstrated that the enzymatic action was not uniform. In addition to the antifelting effects, the enzymatic treatment could lead to an improved degree of whiteness.展开更多
It is extremely important to study and understand the deformation behavior and strength characteristics of rocks under thermal-mechanical （TM） coupling effects. Failure behavior and strength characteristics of Pingd...It is extremely important to study and understand the deformation behavior and strength characteristics of rocks under thermal-mechanical （TM） coupling effects. Failure behavior and strength characteristics of Pingdingshan sandstone were investigated at room temperatures up to 300℃ in an internally heated apparatus and tensile load through meso-scale laboratory experiments in this work. 33 experiments have successfully been conducted for Pingdingshan sandstone. Experimental results indicated that the tensile strength increased slowly with temperatures from 25℃ to 100℃, and then sharply jumped from 100℃ to 150℃, and finally decreased slightly with temperatures from 150℃ to 300℃. And about 150℃ is the threshold temperature of strength and thermal cracking. At low temperatures （25℃-150℃）, sandstone strength is determined by relatively weak clay cement. However, at higher temperatures （150℃-300℃）, because of the strength enhancement of clay cement, sandstone strength is controlled by both mineral particles and clay cement. The effects of cement clay, micro-cracks closing, and thermal cracking were the possible reasons for our detailed analysis. In addition, the typical fracture position maps and nominal stress-strain curves indicated that the temperature had strong effects on the failure mechanism of sandstone. The fractograph implied that the dominant fracture mechanism tended to transform from brittle at low temperatures to ductile at high temperatures.展开更多
文摘An alkaline protease was applied on wool knitted fabric in an attempt to improve its shrink resistance. The influence of process parameters was evaluated and the tensile properties, surface characteristics and whiteness of wool were also studied. The results showed that the action of the protease on wool was significantly enhanced by hydrogen peroxide pretreatment. Based on the preliminary test and subsequent factor analysis, an appropriate combined process was obtained. The SEM investigation of the surface characteristics demonstrated that the enzymatic action was not uniform. In addition to the antifelting effects, the enzymatic treatment could lead to an improved degree of whiteness.
基金supported by the National Natural Science Foundation of China(Grant No.11102225)the Special Funds for Major State Basic Research Project(Grant Nos. 2010CB732002 and 2011CB201201)+2 种基金the National Excellent Doctoral Dissertation of China(Grant No.201030)the Beijing Nova Program (Grant No.2010B062)the New Century Excellent Talents in University(Grant No.NCET-09-0726)
文摘It is extremely important to study and understand the deformation behavior and strength characteristics of rocks under thermal-mechanical （TM） coupling effects. Failure behavior and strength characteristics of Pingdingshan sandstone were investigated at room temperatures up to 300℃ in an internally heated apparatus and tensile load through meso-scale laboratory experiments in this work. 33 experiments have successfully been conducted for Pingdingshan sandstone. Experimental results indicated that the tensile strength increased slowly with temperatures from 25℃ to 100℃, and then sharply jumped from 100℃ to 150℃, and finally decreased slightly with temperatures from 150℃ to 300℃. And about 150℃ is the threshold temperature of strength and thermal cracking. At low temperatures （25℃-150℃）, sandstone strength is determined by relatively weak clay cement. However, at higher temperatures （150℃-300℃）, because of the strength enhancement of clay cement, sandstone strength is controlled by both mineral particles and clay cement. The effects of cement clay, micro-cracks closing, and thermal cracking were the possible reasons for our detailed analysis. In addition, the typical fracture position maps and nominal stress-strain curves indicated that the temperature had strong effects on the failure mechanism of sandstone. The fractograph implied that the dominant fracture mechanism tended to transform from brittle at low temperatures to ductile at high temperatures.
