Objective To observe the clinical efficacy of the needling method for regulating wei qi and strengthening brain on insomnia.Method Two hundred patients with insomnia were randomly divided into a group of regulating we...Objective To observe the clinical efficacy of the needling method for regulating wei qi and strengthening brain on insomnia.Method Two hundred patients with insomnia were randomly divided into a group of regulating wei qi and strengthening brain（group A） and a group of normal acupuncture（group B）through random number table method,with 100 cases in each group.In group A,Baihui（百会 GV20）,Dazhui（大椎 GV 14）,Shenmai（申脉 BL62）,Zhaohai（照海 KI 6） and auricular points Yuanzhong（缘中 AT 2,3,4i）,and Shenmen（神门TF 4） were selected;and in group B,Sishencong（四神聪 EX-HN 1）,Shenmen（神门 HT 7）,and Sanyinjiao（三阴交 SP 6） were selected.Acupuncture was given on these points once daily for 15 days.Pittsburgh sleep quality index（PSQI） was used for scoring and curative effect was evaluated before and after treatment.Results The total effective rate was 89.0%（89/100） in group A and 65.0%（65/100） in group B with a very significant difference between the two groups（P〈0.01）;the difference of PSQI scores before and after treatment was（-9.15±5.68）in group A and（-5.64±5.73）in group B,with a very significant difference before and after treatment in the two groups（P〈0.01）.Conclusion The therapeutic effect of the needling method for regulating wei qi and strengthening brain on insomnia is superior to that of normal needling method.展开更多
Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an averag...Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an average size of approximately 100–200 nm.The addition of nanosized W particles remarkably improves the mechanical properties,while the electrical conductivity did not substantially decrease.The Cu–W composite with 6 wt%W has the most comprehensive properties with an ultimate strength of 310 MPa,yield strength of 238 MPa,hardness of HV 108 and electrical conductivity of 90%IACS.The enhanced mechanical property and only a small loss of electrical conductivity demonstrate the potential of this new strategy to prepare W nanoparticle-strengthened Cu composites.展开更多
Al2O3 dispersion copper alloy powder was prepared by intemal oxidation, and three consolidation methods--high-velocity compaction （HVC）, hot pressing （HP）, and hot extrusion （HE）--were used to prepare Al2O3 disp...Al2O3 dispersion copper alloy powder was prepared by intemal oxidation, and three consolidation methods--high-velocity compaction （HVC）, hot pressing （HP）, and hot extrusion （HE）--were used to prepare Al2O3 dispersion-strengthened copper （Cu-Al2O3） alloys. The microstructures and properties of these alloys were investigated and compared. The results show that the alloys prepared by the HP and HE methods exhibited the coarsest and finest grain sizes, respectively. The alloy prepared by the HVC method exhibited the lowest relative density （98.3% vs. 99.5% for HP and 100% for HE）, which resulted in the lowest electrical conductivity （81% IACS vs. 86% IACS for HP and 87% IACS for HE）. However, this alloy also exhibited the highest hardness （77 HRB vs. 69 HRB for HP and 70 HRB for HE）, the highest compressive strength （443 MPa vs. 386 MPa for I/P and 378 MPa for HE）, and the best hardness retention among the investigated alloys. The results illustrate that the alloy prepared by the HVC method exhibits high softening temperature and good mechanical properties at high temperatures, which imply long service life when used as spot-welding electrodes.展开更多
A poly vinyl alcohol（PVA） scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The streng...A poly vinyl alcohol（PVA） scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The strengthened porous PVA exhibits aligned interconnected porous structures and shows a significant enhancement in tensile testing and compression strength testing.展开更多
The mechanical properties of the hot-rolled plates of Ti steel and Ti-Mo steel after isothermal transformation in a temperature range of 600 700 ℃ for 60 min have been tested, and the microstructures of the matrix an...The mechanical properties of the hot-rolled plates of Ti steel and Ti-Mo steel after isothermal transformation in a temperature range of 600 700 ℃ for 60 min have been tested, and the microstructures of the matrix and the characteristics of precipitated nanometer-sized carbides have also been examined by scanning electron microscopy and transmission electron microscopy. The precipitation regularity of nanometer-sized carbides has been studied by thermodynamic method and the contributions of corresponding strengthening mechanisms to the total yield strength have been calculated. The tensile strength of hot-rolled Ti-Mo ferritie steel can achieve 780 MPa with an elongation of 20.0% after being isothermally treated at 600 ℃ for 60 rain, and the tensile strength of Ti steel is 605 MPa with an elongation of 22.7%, according to the results of tensile tests. The critical nucleation size of （Ti,Mo）C is smaller than that of TiC at a given isothermal temperature, but the nucleation rate of （Ti, Mo）C is larger than that of TiC. The grainrefinement strengthening and precipitation strengthening contribute the main amount of the total yield strength. The major increase in yield strength with the decrease of isothermal temperature results from the contribution of precipi tation strengthening. The contribution of precipitation strengthening to the yield strength of the steels has been esti mated. The ferrite phase can be strengthened by about 400 MPa through precipitation strengthening in Ti-Mo steel isothermally treated at 600 ℃ for 60 rain, which is about 200 MPa higher than that of Ti steel under the same conditions.展开更多
With deepening of domestic market opening up to the outside world and fast developing of domestic economy, many old bridges, especially the highway bridges constructed during 1960~1970, bear the heavy traffic loads, w...With deepening of domestic market opening up to the outside world and fast developing of domestic economy, many old bridges, especially the highway bridges constructed during 1960~1970, bear the heavy traffic loads, which made old highway strengthening project the very pressing task. In this paper, the reason why old bridge is damaged, the requirements for strengthening technology and construction plan for bridge strengthening are analyzed in detail, hopefully, there are some useful proposals provided for old bridge transforming.展开更多
基金Supported by Project of State Administration of Traditional Chinese Medicine:2002 ZL 29
文摘Objective To observe the clinical efficacy of the needling method for regulating wei qi and strengthening brain on insomnia.Method Two hundred patients with insomnia were randomly divided into a group of regulating wei qi and strengthening brain（group A） and a group of normal acupuncture（group B）through random number table method,with 100 cases in each group.In group A,Baihui（百会 GV20）,Dazhui（大椎 GV 14）,Shenmai（申脉 BL62）,Zhaohai（照海 KI 6） and auricular points Yuanzhong（缘中 AT 2,3,4i）,and Shenmen（神门TF 4） were selected;and in group B,Sishencong（四神聪 EX-HN 1）,Shenmen（神门 HT 7）,and Sanyinjiao（三阴交 SP 6） were selected.Acupuncture was given on these points once daily for 15 days.Pittsburgh sleep quality index（PSQI） was used for scoring and curative effect was evaluated before and after treatment.Results The total effective rate was 89.0%（89/100） in group A and 65.0%（65/100） in group B with a very significant difference between the two groups（P〈0.01）;the difference of PSQI scores before and after treatment was（-9.15±5.68）in group A and（-5.64±5.73）in group B,with a very significant difference before and after treatment in the two groups（P〈0.01）.Conclusion The therapeutic effect of the needling method for regulating wei qi and strengthening brain on insomnia is superior to that of normal needling method.
基金supported by the Fundamental Research Funds for the Central Universities (No. FRF-TP-18-029A2)State Key Lab of Advanced Metals and Materials of China (No. 2019-Z10)
文摘Tungsten nanoparticle-strengthened Cu composites were prepared from nanopowder synthesized by a sol–gel method and in-situ hydrogen reduction.The tungsten particles in the Cu matrix were well-dispersed with an average size of approximately 100–200 nm.The addition of nanosized W particles remarkably improves the mechanical properties,while the electrical conductivity did not substantially decrease.The Cu–W composite with 6 wt%W has the most comprehensive properties with an ultimate strength of 310 MPa,yield strength of 238 MPa,hardness of HV 108 and electrical conductivity of 90%IACS.The enhanced mechanical property and only a small loss of electrical conductivity demonstrate the potential of this new strategy to prepare W nanoparticle-strengthened Cu composites.
基金financially supported by Guangdong Provincial Industrial High-tech Project (No. 2015A010105020)Guangzhou Science & Technology New Star of Pearl River Project (No. 2012J2200096)+3 种基金the Open Research Fund of State Key Laboratory of Powder Metallurgy of Central South UniversityGuangdong Provincial Innovation Ability Construction Project (No. 2016B070701024)Guangzhou Innovation Platform Construction and Sharing Project (No. 201509010003)Guangdong Provincial Science & Technology Basic Condition Construction Field Project (No. 2014B030301012)
文摘Al2O3 dispersion copper alloy powder was prepared by intemal oxidation, and three consolidation methods--high-velocity compaction （HVC）, hot pressing （HP）, and hot extrusion （HE）--were used to prepare Al2O3 dispersion-strengthened copper （Cu-Al2O3） alloys. The microstructures and properties of these alloys were investigated and compared. The results show that the alloys prepared by the HP and HE methods exhibited the coarsest and finest grain sizes, respectively. The alloy prepared by the HVC method exhibited the lowest relative density （98.3% vs. 99.5% for HP and 100% for HE）, which resulted in the lowest electrical conductivity （81% IACS vs. 86% IACS for HP and 87% IACS for HE）. However, this alloy also exhibited the highest hardness （77 HRB vs. 69 HRB for HP and 70 HRB for HE）, the highest compressive strength （443 MPa vs. 386 MPa for I/P and 378 MPa for HE）, and the best hardness retention among the investigated alloys. The results illustrate that the alloy prepared by the HVC method exhibits high softening temperature and good mechanical properties at high temperatures, which imply long service life when used as spot-welding electrodes.
基金Supported by the Northwestern Polytechnical University under Grant No 158-QP-2016the Natural Science Basic Research Plan of Shaanxi Province under Grant No 2017JM5112
文摘A poly vinyl alcohol（PVA） scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The strengthened porous PVA exhibits aligned interconnected porous structures and shows a significant enhancement in tensile testing and compression strength testing.
基金Sponsored by National Natural Science Foundation of China(51271035)
文摘The mechanical properties of the hot-rolled plates of Ti steel and Ti-Mo steel after isothermal transformation in a temperature range of 600 700 ℃ for 60 min have been tested, and the microstructures of the matrix and the characteristics of precipitated nanometer-sized carbides have also been examined by scanning electron microscopy and transmission electron microscopy. The precipitation regularity of nanometer-sized carbides has been studied by thermodynamic method and the contributions of corresponding strengthening mechanisms to the total yield strength have been calculated. The tensile strength of hot-rolled Ti-Mo ferritie steel can achieve 780 MPa with an elongation of 20.0% after being isothermally treated at 600 ℃ for 60 rain, and the tensile strength of Ti steel is 605 MPa with an elongation of 22.7%, according to the results of tensile tests. The critical nucleation size of （Ti,Mo）C is smaller than that of TiC at a given isothermal temperature, but the nucleation rate of （Ti, Mo）C is larger than that of TiC. The grainrefinement strengthening and precipitation strengthening contribute the main amount of the total yield strength. The major increase in yield strength with the decrease of isothermal temperature results from the contribution of precipi tation strengthening. The contribution of precipitation strengthening to the yield strength of the steels has been esti mated. The ferrite phase can be strengthened by about 400 MPa through precipitation strengthening in Ti-Mo steel isothermally treated at 600 ℃ for 60 rain, which is about 200 MPa higher than that of Ti steel under the same conditions.
文摘With deepening of domestic market opening up to the outside world and fast developing of domestic economy, many old bridges, especially the highway bridges constructed during 1960~1970, bear the heavy traffic loads, which made old highway strengthening project the very pressing task. In this paper, the reason why old bridge is damaged, the requirements for strengthening technology and construction plan for bridge strengthening are analyzed in detail, hopefully, there are some useful proposals provided for old bridge transforming.
