Through adding different additional water use,the compressive strength,splitting tensile strength and fluidity of recycled concrete of three aggregate combination forms were studied by experiment respectively.The expe...Through adding different additional water use,the compressive strength,splitting tensile strength and fluidity of recycled concrete of three aggregate combination forms were studied by experiment respectively.The experimental results show that with the increase of adding additional water use,the compressive strength and splitting tensile strength of recycled coarse aggregate concrete decrease,but that of recycled fine aggregate concrete and recycled all aggregate concrete increase firstly then decrease.When additional water use is added more 15% or 20% than that of basic ordinary concrete,the recycled coarse aggregate concrete and fine one can get pretty good fluidity.When it is added more 30%,the recycled all aggregate concrete has fluidity that is just satisfied.展开更多
The desulfurization ability of refining slag with relative lower basicity （B） and Al2O3 content （B = 3.5-5.0; 20wt%-25wt% Al2O3） was studied. Firstly, the component activities and sulfide capacity （Cs） of the sl...The desulfurization ability of refining slag with relative lower basicity （B） and Al2O3 content （B = 3.5-5.0; 20wt%-25wt% Al2O3） was studied. Firstly, the component activities and sulfide capacity （Cs） of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution （Ls）. Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO （αCaO）, with no deterioration of Cs compared with conventional desulfurization slag. The measured Ls between high-strength low-alloyed （HSLA） steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.展开更多
目的通过一组单线性梯度洗脱实验获取线性溶剂强度模型的参数值,为色谱图的预测提供所必须的参数值。方法首先,在实验中固定流动相组成的起始和结束值,通过改变梯度洗脱的时间,从而改变梯度的斜率(B)。测定溶质在这些梯度条件下的保留时...目的通过一组单线性梯度洗脱实验获取线性溶剂强度模型的参数值,为色谱图的预测提供所必须的参数值。方法首先,在实验中固定流动相组成的起始和结束值,通过改变梯度洗脱的时间,从而改变梯度的斜率(B)。测定溶质在这些梯度条件下的保留时间,计算其流出色谱柱时所对应的流动相组成(φR)。然后,将描述φR与B之间关系的数学公式对实验数据进行非线性拟合,从而获取线性溶剂强度模型的参数值。拟合基于Levenberg-Marquardt算法,通过Excel中的Visual Basic for Applications(VBA)语言编程实现。结果计算机程序的可靠性通过实验进行验证。以12种芳环化合物为分离的对象,以C18柱为固定相,含1%乙酸的甲醇-水溶液为流动相,应用所编写的程序对单线性梯度洗脱实验数据进行处理,获取溶剂强度模型的参数值。然后,根据所得到的参数值预测多线性梯度洗脱条件下的色谱图,得到的理论色谱图与实验色谱图吻合。结论所建立的方法可快速准确地获取线性溶剂强度模型的参数值,具有良好的实用价值。展开更多
A series of acetate ionic liquids were synthesized using a typical two‐step method.The ionic liquids were used as environmentally benign catalysts in the production of propylene glycol ethers from propylene oxide and...A series of acetate ionic liquids were synthesized using a typical two‐step method.The ionic liquids were used as environmentally benign catalysts in the production of propylene glycol ethers from propylene oxide and alcohols under mild conditions.The basic strengths of the ionic liquids were evaluated by determination of their Hammett functions,obtained using ultraviolet‐visible spectroscopy,and the relationship between their catalytic activities and basicities was established.The catalytic efficiencies of the ionic liquids were higher than that of the traditional basic catalyst NaOH.This can be attributed to the involvement of a novel reaction mechanism when these ionic liquids are used.A possible electrophilic‐nucleophilic dual activation mechanism was proposed and confirmed using electrospray ionization quadrupole time‐of‐flight mass spectrometry.In addition,the effects of significant reaction parameters such as concentration of catalyst,molar ratio of alcohol to propylene oxide,reaction temperature,and steric hindrance of the alcohol were investigated in detail.展开更多
基金Project(Xiangjianke(2007)No.425) supported by Scientific Research Fund of Hunan Provincial Construction DepartmentProject supported by the Youth Framework Teacher Fund of Xiangtan University(2006)
文摘Through adding different additional water use,the compressive strength,splitting tensile strength and fluidity of recycled concrete of three aggregate combination forms were studied by experiment respectively.The experimental results show that with the increase of adding additional water use,the compressive strength and splitting tensile strength of recycled coarse aggregate concrete decrease,but that of recycled fine aggregate concrete and recycled all aggregate concrete increase firstly then decrease.When additional water use is added more 15% or 20% than that of basic ordinary concrete,the recycled coarse aggregate concrete and fine one can get pretty good fluidity.When it is added more 30%,the recycled all aggregate concrete has fluidity that is just satisfied.
基金financially supported by the National Basic Research Program of China (No. 2010CB630806)the State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing (No. 41603015)
文摘The desulfurization ability of refining slag with relative lower basicity （B） and Al2O3 content （B = 3.5-5.0; 20wt%-25wt% Al2O3） was studied. Firstly, the component activities and sulfide capacity （Cs） of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution （Ls）. Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO （αCaO）, with no deterioration of Cs compared with conventional desulfurization slag. The measured Ls between high-strength low-alloyed （HSLA） steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.
文摘目的通过一组单线性梯度洗脱实验获取线性溶剂强度模型的参数值,为色谱图的预测提供所必须的参数值。方法首先,在实验中固定流动相组成的起始和结束值,通过改变梯度洗脱的时间,从而改变梯度的斜率(B)。测定溶质在这些梯度条件下的保留时间,计算其流出色谱柱时所对应的流动相组成(φR)。然后,将描述φR与B之间关系的数学公式对实验数据进行非线性拟合,从而获取线性溶剂强度模型的参数值。拟合基于Levenberg-Marquardt算法,通过Excel中的Visual Basic for Applications(VBA)语言编程实现。结果计算机程序的可靠性通过实验进行验证。以12种芳环化合物为分离的对象,以C18柱为固定相,含1%乙酸的甲醇-水溶液为流动相,应用所编写的程序对单线性梯度洗脱实验数据进行处理,获取溶剂强度模型的参数值。然后,根据所得到的参数值预测多线性梯度洗脱条件下的色谱图,得到的理论色谱图与实验色谱图吻合。结论所建立的方法可快速准确地获取线性溶剂强度模型的参数值,具有良好的实用价值。
基金supported by the One Hundred Talent Program of CASthe National Natural Science Foundation of China Petroleum & Chemical Corporation Joint Fund(U1662129)+1 种基金the National Natural Science Foundation of China(91434203)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDY-SSW-JSC011)~~
文摘A series of acetate ionic liquids were synthesized using a typical two‐step method.The ionic liquids were used as environmentally benign catalysts in the production of propylene glycol ethers from propylene oxide and alcohols under mild conditions.The basic strengths of the ionic liquids were evaluated by determination of their Hammett functions,obtained using ultraviolet‐visible spectroscopy,and the relationship between their catalytic activities and basicities was established.The catalytic efficiencies of the ionic liquids were higher than that of the traditional basic catalyst NaOH.This can be attributed to the involvement of a novel reaction mechanism when these ionic liquids are used.A possible electrophilic‐nucleophilic dual activation mechanism was proposed and confirmed using electrospray ionization quadrupole time‐of‐flight mass spectrometry.In addition,the effects of significant reaction parameters such as concentration of catalyst,molar ratio of alcohol to propylene oxide,reaction temperature,and steric hindrance of the alcohol were investigated in detail.
