A composite layer was prepared on the surface of Ti-6Al-4V alloy by nitriding-sulfurizing composite treatment,and its microstructure and phase structure were examined by scanning electron microscopy（SEM） and X-ray d...A composite layer was prepared on the surface of Ti-6Al-4V alloy by nitriding-sulfurizing composite treatment,and its microstructure and phase structure were examined by scanning electron microscopy（SEM） and X-ray diffraction（XRD）,respectively.The tribological performance was measured to investigate its dependence on the nitriding-sulfurizing composite treatment process.The results indicated that the composite layer was mainly comprised of Ti2N,TiN,and TiS2.It was found that the composite layer exhibited superior tribological properties under dry friction and absolute sliding conditions due to the formation of sulfides with self-lubricating function.展开更多
<div style="text-align:justify;"> Ozone plasma treatment is accessible to be applied on shading adjustment and colour fading because of the capacity of ozone production. It is a green process that trea...<div style="text-align:justify;"> Ozone plasma treatment is accessible to be applied on shading adjustment and colour fading because of the capacity of ozone production. It is a green process that treats dyed cotton fabric under dry condition so as to avoid chemical pollutants. This study means to explore colour reflectance of decolourized sulfur dyed cotton texture using ozone plasma treatment. Sulfur dyed cotton textures with various colour depths (0.5%, 1.5%, 2.5%) were set up to be treated different plasma parameters, including ozone air concentrations (10%, 30%, 50%, 70%), water contents in terms of weight percentage (35%, 45%) of fabric and ozone air plasma treatment periods (10 mins, 20 mins, 30 mins). The colour fading result is assessed by the colour reflectance in percentage (R%) utilizing spectrophotometer under CIE standard illuminant D65. The valid colour fading based on high percentage of reflectance was demonstrated from plasma treatment under higher ozone air concentration (50% and 70% ozone in air) and longer time length of plasma treatment (20 mins and 30 mins). The level of water content contained in the cotton fabrics is appeared to have noteworthy relationship with the degree of decolourization. </div>展开更多
The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing ...The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching con- ditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a proportional re- lationship. A modified shrinking particle model was developed to account for the change in reactive surface area, and the model was fitted to experimental data. The resulting model was observed to describe experimental findings very well. Kinetics analysis revealed that the leach- ing process is controlled by a chemical reaction under the employed experimental conditions and the activation energy of the reaction is 48 kJ.mol-1.展开更多
Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) for 5 minutes,...Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) for 5 minutes, hilar removal, and a control in which the seeds were sown without being treated. The experiment was laid out in the Completely Randomized Design (CRD) with four replicates and 60 seeds per treatment. Seeds were sown in an improvised Seedbox in October 2019. Germination was monitored daily for one month. The results showed that Mamalis seeds treated with lukewarm water have the earliest germination of twelve days, with a germination percentage of 66.67%. The germination rate of another treatment ranges from 0 - 44 percent, compared to 45 percent for the control treatment. It seems prudent to conclude that to enhance the vegetative propagation methods is to soaking in warm water at 37.5˚C for 2 hours could provide the best growth.展开更多
To prepare manganese-containing spinel sulfur transfer agent with acid peptization, ultrasonic wave is used for the first time to modify the structure of sulfur transfer agent in this work. Mini fixed bed reactor was ...To prepare manganese-containing spinel sulfur transfer agent with acid peptization, ultrasonic wave is used for the first time to modify the structure of sulfur transfer agent in this work. Mini fixed bed reactor was used to investigate the effect of ultrasonic power, time and temperature on the structure and oxidation adsorption performance of sulfur transfer agent and the adsorption kinetics and mechanism of SO2 were analyzed. SEM, TEM, XRD and N2 adsorption-desorption techniques were employed to characterize and analyse the function of sulfur transfer agent. The results indicated that manganese-containing spinel is a kind of promising sulfur transfer agent and exhibits higher sulfur capacity and desulfurization degree under the selected conditions of the ultrasonic wave power of 60%, and with the treatment period for 3 h at a temperature of 60 ℃.展开更多
为研究不同预处理对赛买提杏片热风干燥特性及水分迁移规律的影响,以切分去核的赛买提杏片为原料,在消除酶促褐变的基础上,经4种预处理(热水漂烫、蒸汽漂烫、微波处理及硫处理),探究3个温度(40,50,60℃)下的干燥特性、水分有效扩散系数...为研究不同预处理对赛买提杏片热风干燥特性及水分迁移规律的影响,以切分去核的赛买提杏片为原料,在消除酶促褐变的基础上,经4种预处理(热水漂烫、蒸汽漂烫、微波处理及硫处理),探究3个温度(40,50,60℃)下的干燥特性、水分有效扩散系数及活化能,并建立干燥动力学模型,研究模型参数与干燥温度间的关系。结合低场核磁共振(LF-NMR)和成像技术(MRI),通过横向弛豫时间和成像伪彩图的变化阐明干燥过程中杏片内部水分迁移规律。结果表明:与40℃相比,经4种预处理的杏片干燥耗时分别缩短41.67%,36.36%,53.85%,50.00%。Deff随着温度的升高而增大,主要在5.9637×10^(-7)~1.3530×10^(-6)m^(2)/s范围。基于干燥动力学进行模型拟合,漂烫及微波等热处理的最适模型均为Wang and Singh模型,R2分别为0.9929,0.9955,0.9942,而非热预处理的硫处理最适模型为Page模型(R^(2)=0.9967)。LF-NMR试验表明干燥前期主要由表面汽化为主,杏片中自由水最先被脱除,干燥后期由内部扩散控制,部分自由水转化为不易流动水和结合水,水分扩散速率降低。护色预处理结合热风干燥对杏片干燥特性及水分迁移均有一定影响。方差分析显示,4种护色处理方式在各温度干燥时Deff无显著差异(P>0.05),干燥温度对干燥过程中的水分扩散起决定性作用。结合低场核磁共振技术可知,微波和硫处理组杏片至干燥结束,在干燥温度50℃和60℃,干燥时间相较于漂烫处理组可缩短4 h。展开更多
文摘A composite layer was prepared on the surface of Ti-6Al-4V alloy by nitriding-sulfurizing composite treatment,and its microstructure and phase structure were examined by scanning electron microscopy（SEM） and X-ray diffraction（XRD）,respectively.The tribological performance was measured to investigate its dependence on the nitriding-sulfurizing composite treatment process.The results indicated that the composite layer was mainly comprised of Ti2N,TiN,and TiS2.It was found that the composite layer exhibited superior tribological properties under dry friction and absolute sliding conditions due to the formation of sulfides with self-lubricating function.
文摘<div style="text-align:justify;"> Ozone plasma treatment is accessible to be applied on shading adjustment and colour fading because of the capacity of ozone production. It is a green process that treats dyed cotton fabric under dry condition so as to avoid chemical pollutants. This study means to explore colour reflectance of decolourized sulfur dyed cotton texture using ozone plasma treatment. Sulfur dyed cotton textures with various colour depths (0.5%, 1.5%, 2.5%) were set up to be treated different plasma parameters, including ozone air concentrations (10%, 30%, 50%, 70%), water contents in terms of weight percentage (35%, 45%) of fabric and ozone air plasma treatment periods (10 mins, 20 mins, 30 mins). The colour fading result is assessed by the colour reflectance in percentage (R%) utilizing spectrophotometer under CIE standard illuminant D65. The valid colour fading based on high percentage of reflectance was demonstrated from plasma treatment under higher ozone air concentration (50% and 70% ozone in air) and longer time length of plasma treatment (20 mins and 30 mins). The level of water content contained in the cotton fabrics is appeared to have noteworthy relationship with the degree of decolourization. </div>
基金support from the China Scholarship Council (CSC) for the visit of Qing Zhao to bo Akademi University, FinlandThe National Key Basic Research Program of China (No. 2012CB626812)+2 种基金the Program for New Century Excellent Talents in Universities of the Ministry of Education of China (No. NCET-11-0077)the Natural Science Foundation of Liaoning Province of China (No. 201102062)the "123 Project" of Liaoning Environmental Research of Geping Green Acts
文摘The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching con- ditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a proportional re- lationship. A modified shrinking particle model was developed to account for the change in reactive surface area, and the model was fitted to experimental data. The resulting model was observed to describe experimental findings very well. Kinetics analysis revealed that the leach- ing process is controlled by a chemical reaction under the employed experimental conditions and the activation energy of the reaction is 48 kJ.mol-1.
文摘Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) for 5 minutes, hilar removal, and a control in which the seeds were sown without being treated. The experiment was laid out in the Completely Randomized Design (CRD) with four replicates and 60 seeds per treatment. Seeds were sown in an improvised Seedbox in October 2019. Germination was monitored daily for one month. The results showed that Mamalis seeds treated with lukewarm water have the earliest germination of twelve days, with a germination percentage of 66.67%. The germination rate of another treatment ranges from 0 - 44 percent, compared to 45 percent for the control treatment. It seems prudent to conclude that to enhance the vegetative propagation methods is to soaking in warm water at 37.5˚C for 2 hours could provide the best growth.
基金supported by the National Natural Science Foundation of China(21306162)Qing Lan Project+1 种基金the State Key Laboratory of Heavy Oil Processing(SKLOP20140205)the National 973 Project of China(2010CB226903)
文摘To prepare manganese-containing spinel sulfur transfer agent with acid peptization, ultrasonic wave is used for the first time to modify the structure of sulfur transfer agent in this work. Mini fixed bed reactor was used to investigate the effect of ultrasonic power, time and temperature on the structure and oxidation adsorption performance of sulfur transfer agent and the adsorption kinetics and mechanism of SO2 were analyzed. SEM, TEM, XRD and N2 adsorption-desorption techniques were employed to characterize and analyse the function of sulfur transfer agent. The results indicated that manganese-containing spinel is a kind of promising sulfur transfer agent and exhibits higher sulfur capacity and desulfurization degree under the selected conditions of the ultrasonic wave power of 60%, and with the treatment period for 3 h at a temperature of 60 ℃.
文摘为研究不同预处理对赛买提杏片热风干燥特性及水分迁移规律的影响,以切分去核的赛买提杏片为原料,在消除酶促褐变的基础上,经4种预处理(热水漂烫、蒸汽漂烫、微波处理及硫处理),探究3个温度(40,50,60℃)下的干燥特性、水分有效扩散系数及活化能,并建立干燥动力学模型,研究模型参数与干燥温度间的关系。结合低场核磁共振(LF-NMR)和成像技术(MRI),通过横向弛豫时间和成像伪彩图的变化阐明干燥过程中杏片内部水分迁移规律。结果表明:与40℃相比,经4种预处理的杏片干燥耗时分别缩短41.67%,36.36%,53.85%,50.00%。Deff随着温度的升高而增大,主要在5.9637×10^(-7)~1.3530×10^(-6)m^(2)/s范围。基于干燥动力学进行模型拟合,漂烫及微波等热处理的最适模型均为Wang and Singh模型,R2分别为0.9929,0.9955,0.9942,而非热预处理的硫处理最适模型为Page模型(R^(2)=0.9967)。LF-NMR试验表明干燥前期主要由表面汽化为主,杏片中自由水最先被脱除,干燥后期由内部扩散控制,部分自由水转化为不易流动水和结合水,水分扩散速率降低。护色预处理结合热风干燥对杏片干燥特性及水分迁移均有一定影响。方差分析显示,4种护色处理方式在各温度干燥时Deff无显著差异(P>0.05),干燥温度对干燥过程中的水分扩散起决定性作用。结合低场核磁共振技术可知,微波和硫处理组杏片至干燥结束,在干燥温度50℃和60℃,干燥时间相较于漂烫处理组可缩短4 h。
