The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the...The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the factors is slope surface material > slope gradient > block shape > block mass. All the factors except block mass have the F value greater than the critical value, suggesting that these three factors are the key factors affecting the rockfall rolling velocity. Factor interaction analysis shows that the effect of the slope gradient relies largely on the slope surface conditions, and the block shape has little influence if the slope gradient is larger than a critical value. An empirical model considering the three key factors is proposed to estimate the rolling velocity, of which the error is limited to 5% of the testing value. This model is validated by 73 field tests, and the prediction shows excellent correlation with the site test. Thus, this analysis can be used as a tool in the rockfall behavior analysis.展开更多
Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bond...Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bonding mechanism of the cold welding sealing process （CWSP） is investigated and compared with the experimental results obtained from the bonding interface analysis. An orthogonal experiment is conducted to observe the effects of various parameters, including the sealing gap, sealing length, sealing diameter, and sealing velocity on bonding strength. A method with the utilization of saturated vapor pressure inside a copper tube is proposed to evaluate bonding strength. A corresponding finite element model is developed to investigate the effects of sealing gap and sealing velocity on plastic deformation during the cold welding process. Effects of various parameters on the bonding strength are determined and it is found that the sealing gap is the most critical factor and that the sealing velocity contributes the least effect. The best parameter combination （AIB3CID3, with a 0.5 mm sealing gap, 6 mm sealing length, 3.8 mm sealing diameter, and 50 mm/s sealing velocity） is derived within the experimental parameters. Plastic deformation results derived from the finite element model are consistent with those from the experiment. The instruction for the CWSP of heat pipes and the design of sealing dies of heat pipes are provided.展开更多
为了研究超高压提取山楂叶中黄酮类化合物的最佳工艺,采用超高压技术常温提取,正交试验优化,分光光度法检测山楂叶中黄酮类化合物的含量。结果表明:超高压提取山楂叶中黄酮类化合物的最佳提取工艺参数为:提取溶剂为50%乙醇,提取压力为40...为了研究超高压提取山楂叶中黄酮类化合物的最佳工艺,采用超高压技术常温提取,正交试验优化,分光光度法检测山楂叶中黄酮类化合物的含量。结果表明:超高压提取山楂叶中黄酮类化合物的最佳提取工艺参数为:提取溶剂为50%乙醇,提取压力为400 MPa,料液比为1∶45,提取温度为60℃,提取时间为3 m in。该超高压提取工艺具有提取效率高、时间短、杂质含量少等优点。展开更多
基金supported by the National Science Foundation of China (Grant No. 41572302)the Funds for Creative Research Groups of China (Grant No. 41521002)
文摘The effects of slope surface material, slope gradient, block shape, and block mass conditions on rockfall rolling velocity were estimated with orthogonal test approach. Visual analysis shows that the importance of the factors is slope surface material > slope gradient > block shape > block mass. All the factors except block mass have the F value greater than the critical value, suggesting that these three factors are the key factors affecting the rockfall rolling velocity. Factor interaction analysis shows that the effect of the slope gradient relies largely on the slope surface conditions, and the block shape has little influence if the slope gradient is larger than a critical value. An empirical model considering the three key factors is proposed to estimate the rolling velocity, of which the error is limited to 5% of the testing value. This model is validated by 73 field tests, and the prediction shows excellent correlation with the site test. Thus, this analysis can be used as a tool in the rockfall behavior analysis.
基金Supported by National Natural Science Foundation of China(Grant Nos.51175186,51675185)Guangdong Provincial Natural Science Foundation of China(Grant No.S2013020012757)EU project PIIF-GA-2012-332304(Grant No.ESR332304)
文摘Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bonding mechanism of the cold welding sealing process （CWSP） is investigated and compared with the experimental results obtained from the bonding interface analysis. An orthogonal experiment is conducted to observe the effects of various parameters, including the sealing gap, sealing length, sealing diameter, and sealing velocity on bonding strength. A method with the utilization of saturated vapor pressure inside a copper tube is proposed to evaluate bonding strength. A corresponding finite element model is developed to investigate the effects of sealing gap and sealing velocity on plastic deformation during the cold welding process. Effects of various parameters on the bonding strength are determined and it is found that the sealing gap is the most critical factor and that the sealing velocity contributes the least effect. The best parameter combination （AIB3CID3, with a 0.5 mm sealing gap, 6 mm sealing length, 3.8 mm sealing diameter, and 50 mm/s sealing velocity） is derived within the experimental parameters. Plastic deformation results derived from the finite element model are consistent with those from the experiment. The instruction for the CWSP of heat pipes and the design of sealing dies of heat pipes are provided.
文摘为了研究超高压提取山楂叶中黄酮类化合物的最佳工艺,采用超高压技术常温提取,正交试验优化,分光光度法检测山楂叶中黄酮类化合物的含量。结果表明:超高压提取山楂叶中黄酮类化合物的最佳提取工艺参数为:提取溶剂为50%乙醇,提取压力为400 MPa,料液比为1∶45,提取温度为60℃,提取时间为3 m in。该超高压提取工艺具有提取效率高、时间短、杂质含量少等优点。
