Influence of heat treatment on the microstructures and mechanical properties of sand-cast Mg-4Y-2Nd-1Gd-0.4Zr magnesium alloy was investigated,and the tensile fracture mechanisms of the studied alloys under different ...Influence of heat treatment on the microstructures and mechanical properties of sand-cast Mg-4Y-2Nd-1Gd-0.4Zr magnesium alloy was investigated,and the tensile fracture mechanisms of the studied alloys under different conditions were also discussed.The results show that the optimum T4 and T6 heat treatment conditions for the as-cast Mg-4Y-2Nd-1Gd-0.4Zr alloy are 525°C,8 h and（525°C,8 h）＋（225°C,16 h）,respectively,with regard to the microstructure observation,DSC heating curve and mechanical properties.The hardness,yield strength,ultimate tensile strength and elongation of the Mg-4Y-2Nd-1Gd-0.4Zr alloy treated by optimum T6 heat treatment are HV91,180 MPa,297 MPa and 7.4%,respectively.Moreover,the Mg-4Y-2Nd-1Gd-0.4Zr alloys under different heat treatment conditions exhibit different tensile fracture modes.展开更多
The 2nd International Association of Neurorestoratology Annual Conference （IANAC） was successfully held in Beijing, China, from April 24 to 26, 2009. More than 200 representatives from 30 countries and regions atten...The 2nd International Association of Neurorestoratology Annual Conference （IANAC） was successfully held in Beijing, China, from April 24 to 26, 2009. More than 200 representatives from 30 countries and regions attended the meeting and carried out extensive academic communications and reached important consensus on many issues in neuroregeneration, neural structural repair, neural replacement, neuroprotection, neuromodulation, neurorehabilitation, neuroplasticity and other areas in the field of neurorestoratology. The genera/assembly adopted ＂Beijing Declaration of International Association of Neurorestoratology＂ （Beijing Declaration） that was proposed by 32 scientists from 18 countries.展开更多
<div style="text-align:justify;"> Based on the detailed interpretation of high-accuracy 3D seismic data, the characteristics of regional unconformities, fracture systems, sedimentary filling and paleo-...<div style="text-align:justify;"> Based on the detailed interpretation of high-accuracy 3D seismic data, the characteristics of regional unconformities, fracture systems, sedimentary filling and paleo-stress field in Zhu 1 depression were comprehensively analyzed. The results showed that 2nd episode of Zhu-Qiong movement was an important tectonic transformation that occurred during rifting, basin structure patterns above and below the regional angular unconformity caused by 2nd episode had distinct differences. The orientations of those basin-controlling faults changed from NE, NEE to EW, NWW, which indicated that the paleo-stress field veered from NNW extension clockwise to sub-NS extension and basin structures patterns transformed from NE, NEE strong rifting to sub-EW, NWW weak rifting. The depocenter showed seesaw-like migration from S to N. And the sedimentary systems transformed from semi-deep-deep lacustrine facies to braided river delta facies developed in shore-shallow lacustrine. Combined with its tectonic recombination of periphery plates that period, the mechanism of above tectonic transformation had direct correspondence to the readjustment of the Indian plate and the Pacific plate. The southward subduction of the pro-to-south China Sea is the direct cause of this tectonic transformation. </div>展开更多
HTP practice,alloyed with low-carbon (less than 0.06%) and high-niobium (up to 0.11%),has been developed to produce large-wall X80 hot rolled strip for 2nd West-East Gas Pipeline project successfully.In this paper,exi...HTP practice,alloyed with low-carbon (less than 0.06%) and high-niobium (up to 0.11%),has been developed to produce large-wall X80 hot rolled strip for 2nd West-East Gas Pipeline project successfully.In this paper,existing status of niobium at different rolling stage,such as reheating,rough rolling and final product and strengthening effects have been presented and analyzed systematically.Some technological questions concerrned,such as the mixed grain occurred on the delay table,dynamic recrystallization during the finish rolling course,γ→αtransformation and final microstructure obtained at low coiling temperature,have been explored further.Analytical results presented increased recrystallization stop temperature due to high niobium contents can provide the requisite to remove waiting-temperature operation of transfer bar before finish rolling to ensure controlled effect of traditional low-temperature,which is benificial not only to production efficiency,but also to uniformity of austenite microstructure.Secondly,dynamic-recrystallization occurred during finish rolling may reduce the density of dislocation,but will better the grain gradient along the thickness because the dynamic recrystallization proceeds instantly,which is beneficial to reduce the appearance of separation of impact fracture.Finally,the lower coiling temperature than traditional TMCP practice,up to 300℃,is a key factor to obtain low-carbon bainite microstructure composed of acicular ferrite and small amount M/A component,which results in high strength and excellent low-temperature toughness.展开更多
The modern research on basic concept inTCM deeply explored The papers in this congress are referring tothe research on Zhenghou(syndrome)theory,Five Element theory and Four Diagnosis theory by
The 2nd International Conference on Rare Earth Development and Applications(ICRE’91),which wassponsored by the Chinese Society of Rare Earths,was held at Beijing International Convention Centre fromMay 27 through May...The 2nd International Conference on Rare Earth Development and Applications(ICRE’91),which wassponsored by the Chinese Society of Rare Earths,was held at Beijing International Convention Centre fromMay 27 through May 31,1991.290 scientists attended this conference,among them there were 63 foreign sci-entists.Prof.Yu Zongsen,vice-chairman of the Chinese Society of Rare Earths,presided over the openingceremony.Mr.Xu Daquan,deputy director of the Rare Earth Leading Group of the State Council,vice-minister展开更多
ZTE Corporation announced on March 31, 2008 that it has been ranked second in terms of CDMA equipment competitiveness by the Yankee Group in a report entitled "ZTE Shines in CDMA Market" published by the res...ZTE Corporation announced on March 31, 2008 that it has been ranked second in terms of CDMA equipment competitiveness by the Yankee Group in a report entitled "ZTE Shines in CDMA Market" published by the research firm in February this year. According to the report, ZTE is the most competitive telecom vendor in China, India, emerging Asia-Pacific market, Africa and Eastern Europe. ZTE tallied the highest score in four out of seven categories the Yankee Group used to measure the CDMA competitiveness of each vendor. The seven key evaluation factors were price, technology, existing installed base, product portfolio, integration capability, government support and company culture.展开更多
基金Project(0502)supported by the Aerospace Science and Technology Innovation Fund of China Aerospace Science and Technology CorporationProject(2007CB613701)supported by the National Basic Research Program of ChinaProject(2009AA033501)supported by the National High-tech Research and Development Program of China
文摘Influence of heat treatment on the microstructures and mechanical properties of sand-cast Mg-4Y-2Nd-1Gd-0.4Zr magnesium alloy was investigated,and the tensile fracture mechanisms of the studied alloys under different conditions were also discussed.The results show that the optimum T4 and T6 heat treatment conditions for the as-cast Mg-4Y-2Nd-1Gd-0.4Zr alloy are 525°C,8 h and（525°C,8 h）＋（225°C,16 h）,respectively,with regard to the microstructure observation,DSC heating curve and mechanical properties.The hardness,yield strength,ultimate tensile strength and elongation of the Mg-4Y-2Nd-1Gd-0.4Zr alloy treated by optimum T6 heat treatment are HV91,180 MPa,297 MPa and 7.4%,respectively.Moreover,the Mg-4Y-2Nd-1Gd-0.4Zr alloys under different heat treatment conditions exhibit different tensile fracture modes.
文摘The 2nd International Association of Neurorestoratology Annual Conference （IANAC） was successfully held in Beijing, China, from April 24 to 26, 2009. More than 200 representatives from 30 countries and regions attended the meeting and carried out extensive academic communications and reached important consensus on many issues in neuroregeneration, neural structural repair, neural replacement, neuroprotection, neuromodulation, neurorehabilitation, neuroplasticity and other areas in the field of neurorestoratology. The genera/assembly adopted ＂Beijing Declaration of International Association of Neurorestoratology＂ （Beijing Declaration） that was proposed by 32 scientists from 18 countries.
文摘<div style="text-align:justify;"> Based on the detailed interpretation of high-accuracy 3D seismic data, the characteristics of regional unconformities, fracture systems, sedimentary filling and paleo-stress field in Zhu 1 depression were comprehensively analyzed. The results showed that 2nd episode of Zhu-Qiong movement was an important tectonic transformation that occurred during rifting, basin structure patterns above and below the regional angular unconformity caused by 2nd episode had distinct differences. The orientations of those basin-controlling faults changed from NE, NEE to EW, NWW, which indicated that the paleo-stress field veered from NNW extension clockwise to sub-NS extension and basin structures patterns transformed from NE, NEE strong rifting to sub-EW, NWW weak rifting. The depocenter showed seesaw-like migration from S to N. And the sedimentary systems transformed from semi-deep-deep lacustrine facies to braided river delta facies developed in shore-shallow lacustrine. Combined with its tectonic recombination of periphery plates that period, the mechanism of above tectonic transformation had direct correspondence to the readjustment of the Indian plate and the Pacific plate. The southward subduction of the pro-to-south China Sea is the direct cause of this tectonic transformation. </div>
文摘HTP practice,alloyed with low-carbon (less than 0.06%) and high-niobium (up to 0.11%),has been developed to produce large-wall X80 hot rolled strip for 2nd West-East Gas Pipeline project successfully.In this paper,existing status of niobium at different rolling stage,such as reheating,rough rolling and final product and strengthening effects have been presented and analyzed systematically.Some technological questions concerrned,such as the mixed grain occurred on the delay table,dynamic recrystallization during the finish rolling course,γ→αtransformation and final microstructure obtained at low coiling temperature,have been explored further.Analytical results presented increased recrystallization stop temperature due to high niobium contents can provide the requisite to remove waiting-temperature operation of transfer bar before finish rolling to ensure controlled effect of traditional low-temperature,which is benificial not only to production efficiency,but also to uniformity of austenite microstructure.Secondly,dynamic-recrystallization occurred during finish rolling may reduce the density of dislocation,but will better the grain gradient along the thickness because the dynamic recrystallization proceeds instantly,which is beneficial to reduce the appearance of separation of impact fracture.Finally,the lower coiling temperature than traditional TMCP practice,up to 300℃,is a key factor to obtain low-carbon bainite microstructure composed of acicular ferrite and small amount M/A component,which results in high strength and excellent low-temperature toughness.
文摘The modern research on basic concept inTCM deeply explored The papers in this congress are referring tothe research on Zhenghou(syndrome)theory,Five Element theory and Four Diagnosis theory by
文摘The 2nd International Conference on Rare Earth Development and Applications(ICRE’91),which wassponsored by the Chinese Society of Rare Earths,was held at Beijing International Convention Centre fromMay 27 through May 31,1991.290 scientists attended this conference,among them there were 63 foreign sci-entists.Prof.Yu Zongsen,vice-chairman of the Chinese Society of Rare Earths,presided over the openingceremony.Mr.Xu Daquan,deputy director of the Rare Earth Leading Group of the State Council,vice-minister
文摘ZTE Corporation announced on March 31, 2008 that it has been ranked second in terms of CDMA equipment competitiveness by the Yankee Group in a report entitled "ZTE Shines in CDMA Market" published by the research firm in February this year. According to the report, ZTE is the most competitive telecom vendor in China, India, emerging Asia-Pacific market, Africa and Eastern Europe. ZTE tallied the highest score in four out of seven categories the Yankee Group used to measure the CDMA competitiveness of each vendor. The seven key evaluation factors were price, technology, existing installed base, product portfolio, integration capability, government support and company culture.
