A newlywed farmer and his wife were visitedby her mother,who immediately demanded aninspection of the place.The farmer had genuinelytried to be friendly to his new mother-in-law,hopingthat it could be a friendly,non-a...A newlywed farmer and his wife were visitedby her mother,who immediately demanded aninspection of the place.The farmer had genuinelytried to be friendly to his new mother-in-law,hopingthat it could be a friendly,non-antagonistic(非对抗性的)relationship.All to no avail though,as shekept nagging(不断的唠叨)them at every opportunity,demanding changes,offering unwanted advice,展开更多
The effects of an electric field on AIN precipitation and recrystallization texture were investigated. Cold-rolled 08Al killed steel sheets were annealed at 550℃ according to the two-step processes, for various maint...The effects of an electric field on AIN precipitation and recrystallization texture were investigated. Cold-rolled 08Al killed steel sheets were annealed at 550℃ according to the two-step processes, for various maintaining times, with and without applying an electric field. It was found that the electric field promotes the precipitation of the second phase (AlN particles), strengthens the γ-fiber and weakens the α-fiber texture component in the recrystallized specimens. A possible explanation for the reinforcement of γ-fiber texture by the electric field is that the second phase AIN particle promotes the growth of γ-fiber at the expense of differently oriented grains.展开更多
Aluminum killed cold rolled steel used for automobiles was welded in this paper by using CO 2 laser with wavelength 10.6μm.The experiment shows that high quality of welding can be realized at welding speed of 4 500m...Aluminum killed cold rolled steel used for automobiles was welded in this paper by using CO 2 laser with wavelength 10.6μm.The experiment shows that high quality of welding can be realized at welding speed of 4 500mm/min by optimizing the parameters.The strength and hardness of laser welded joints for aluminum killed cold rolled steel increased compared to those of the base metal while the formability decreased.Forming limit diagram of joint material indicated that the laser weld seam should avoid the maximum deformation area of automobile parts during the designing period for the position of weld seam.展开更多
In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Pro...In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Probe Microanalysis) and by analyzing the total oxygen. The results showed that in the slabs the total oxygen was quite low and the inclusions discovered were mainly small-sized angular alumina inclusions. This indicates that most inclusions have been removed by floating out during the continuous casting process. In addition, the countermeasures were discussed to decrease the alumina inclusions in the slabs further.展开更多
In this study, the intercritical annealing process for a typical low-carbon aluminum killed steel is investigated. A cold-rolled sheet was annealed at intercfitical temperatures ranging from 730 ℃ to 770 ℃ and then ...In this study, the intercritical annealing process for a typical low-carbon aluminum killed steel is investigated. A cold-rolled sheet was annealed at intercfitical temperatures ranging from 730 ℃ to 770 ℃ and then cooled in air or water. The annealed steel was then baked at 210 ℃, and its mechanical properties and microstructures were analyzed in detail. It is shown that after the air-cooling process,the strength of steel decreased and ductility increased with an increase in the annealing temperature. However, after water-cooling, the strength and ductility both increased with the increase of annealing temperature. These results are attributed to the property- optimization of the steel.展开更多
我们初次见到谚语Care killed a(the) cat,也许会莫明这“忧虑杀死猫”之奥妙。甚至看到辞书对此的中译——“忧虑伤人”,也未必能将两者挂钩。这里涉及到我们对该谚语的文化历史背景了解的问题。 Care killed a(the)cat源于莎士比亚《...我们初次见到谚语Care killed a(the) cat,也许会莫明这“忧虑杀死猫”之奥妙。甚至看到辞书对此的中译——“忧虑伤人”,也未必能将两者挂钩。这里涉及到我们对该谚语的文化历史背景了解的问题。 Care killed a(the)cat源于莎士比亚《捕风捉影》一剧的第五幕第一场。该谚语与A cat has nine lives (猫有九条命)这条谚语有密切的关系。展开更多
Background: We previously showed that treatment with Mycobacterium bovis BCG killed by extended freeze-drying (EFD BCG) modulates inflammation through regulatory T cells (Tregs) in an acute asthma model. In this study...Background: We previously showed that treatment with Mycobacterium bovis BCG killed by extended freeze-drying (EFD BCG) modulates inflammation through regulatory T cells (Tregs) in an acute asthma model. In this study, we investigated the kinetics of Treg induction as well as their long-term homing in spleen and lungs correlating with reduced airway hyperresponsiveness (AHR) in a murine model of acute allergic asthma. We then evaluated the therapeutic implication of EFD BCG in a chronic asthma model. Methods: Tregs expressing Foxp3 were analyzed in various organs shortly and long-term after EFD BCG, live- and Heat Killed-(HK-) BCG treatments in an acute model of asthma. We further studied EFD BCG treatment on airway inflammation using a chronic model of asthma in mice. Results: Foxp3 expression peaked in the inguinal draining lymph-nodes (iDLNs) 2-4 days after EFD BCG treatment whereas it was long-term observed in spleen (days 7 to 90). This increase in Foxp3 expression was also found in lungs upon intranasal ovalbumin (OVA) challenge in OVA-sensitized mice. The loss of protection 4 months after EFD BCG treatment was correlated with the end of this phenomenon. Moreover, major lung inflammation hallmarks of severe asthma after multiple allergen challenges promoting chronic airway inflammation in OVA sensitized mice were reduced by EFD BCG treatment: AHR, eosinophils and neutrophils in bronchoalveolar lavage (BAL), mucus metaplasia, Th2 as well as Th17 cytokine levels in BAL and sera. EFD BCG treatment also enhances PPAR-γ expression and regulates NF-κBp65 translocation in lung extracts in this model of chronic asthma. Conclusions: EFD BCG treatment induced long-term protective effect associated to Foxp3 Tregs in the spleen and lungs in an acute model of asthma and inhibits AHR in a chronic model of asthma. EFD BCG could be a new and promising immuno-modulatory alternative treatment to corticoids in severe human asthma.展开更多
The continuous annealing process of a typical aluminum killed steel was investigated. A cold rolled sheet was annealed continuously at holding temperature ranging from 580 to 760 ℃. The microstructures were analyzed ...The continuous annealing process of a typical aluminum killed steel was investigated. A cold rolled sheet was annealed continuously at holding temperature ranging from 580 to 760 ℃. The microstructures were analyzed in detail based on contiuous cooling transformation( CCT) curves that were simulated with JM artP ro softw are. The results show ed that recrystallization and perlitic transformations caused a diversity of microstructures and mechanical properties. In comparison with annealed steel that was produced from insufficient recrystallization,annealed steel produced from sufficient recrystallization had more isometric grains and exhibited low er strength and higher ductility. Higher annealing temperatures than A_1 provided steel with lamellar pearlite zones,large ferrite grains,low strength,and high ductility. The results are attributed to the property optimization of the steel.展开更多
1.In the 40 meters deep of an ocean. there is an underwater creature institute (研究所).There the researchers(研究员) observe the way of life of dolphins (海豚 and whales(鲸鱼).
Violence in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region, has left at least three civilians and an armed police officer dead on Sunday (July 5), sources with the regional government said ea...Violence in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region, has left at least three civilians and an armed police officer dead on Sunday (July 5), sources with the regional government said early Monday.展开更多
EDITOR’S NOTE:on January 3, 1991, when the worldwas Still immersed in the New Y6ar celebrstions, 17 Chineseand Japanese mountaineers, climbing the Meili Mountain atthe juncture Of "bet and Yunnan, were report6d ...EDITOR’S NOTE:on January 3, 1991, when the worldwas Still immersed in the New Y6ar celebrstions, 17 Chineseand Japanese mountaineers, climbing the Meili Mountain atthe juncture Of "bet and Yunnan, were report6d missing. BothChinese and Japanese forces tried in vain to organized a rescue. But in July 1997, the bodies of the missing mountaineerswere found tragically killed by an avalanche. In China’s Tibet,detailed reports have been carried out by Mr. Zhou Zhen(issue No.4, 1997), the first-generstion mountaineer of Chinaand now professor with the PE Science Research Institute ofthe State Physical Education General Administrstion. The following is an abstract from Mr. Zhou Zhen’s latest report.展开更多
Titanium is the impurity in some special steel grades.The existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various properties.Thus,titanium ...Titanium is the impurity in some special steel grades.The existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various properties.Thus,titanium should be removed to the minimum.Based on the industrial production of ultra low carbon Al-Si killed steel,the physical-chemical behavior of titanium was investigated in vacuum degassing refining(RH)process with and without desulfurization.The influences of titanium content in hot metal,ladle slag composition,and ladle slag quantity,etc,on titanium content of refined liquid steel were discussed.The results showed that the partition ratio of titanium between ladle slag and liquid steel is in inverse proportion to the 4/3square of aluminum content.The maximum partition ratio of titanium between top slag and liquid steel can be obtained by adjusting an optimum slag composition including contents of FeOxand Al2O3and the slag basicity,and the suitable range of them should be controlled higher than 6%,less than 20%,and within 1.5to 3.0,respectively.Moreover,desulfurization refining by RH decreases the partition ratio of titanium between ladle slag and liquid steel significantly.To ensure the titanium content stably less than 15×10-6 in a 300tladle,the titanium content in hot metal must be less than 500×10-6 and the thickness of basic oxygen furnace(BOF)slag carrying over must be less than 50mm.展开更多
The equilibrium problem of Green potentials for the Brownian motion has attracted general attention. The existence of equilibrium measure μ_B is proved, and the fundamental relation between the potential kernel u(x, ...The equilibrium problem of Green potentials for the Brownian motion has attracted general attention. The existence of equilibrium measure μ_B is proved, and the fundamental relation between the potential kernel u(x, y), the last exit time γ_B of B and the equilibrium measure μ_B, is given in (5) for the killed Markov processes.展开更多
In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expans...In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expansion for the transition density, we prove the existence and uniqueness of both quasi-stationary distribution (qsd) and mean ratio quasi-stationary distribution (mrqsd). The later is shown to be closely related to laws of large numbers (LLN) and to quasi-ergodicity. We further show that the mrqsd is the unique stationary distribution of a certain limiting ergodic diffusion process of the BM conditioned on not having been killed. We also show that a phase transition occurs from mrqsd to qsd. On the other hand, we study the large deviation behavior related to the above problems. A key observation is that the mrqsd is the unique minimum of certain large deviation rate function. We further prove that the limiting diffusion process also satisfies a large deviation principle with the rate function attaining its unique minimum at the mrqsd. These give interpretations of the mrqsd from different points of view, and establish some intrinsic connections among the above topics. Some general results concerning Yaglom limit, moment convergence and LLN are also obtained.展开更多
China-based websites mimicking the Groupon model fight for survival in a vicious, overcrowded market After a year of reckless expansion,China’s group buying websites are facing some chilly headwinds.Gaopeng.com, a jo...China-based websites mimicking the Groupon model fight for survival in a vicious, overcrowded market After a year of reckless expansion,China’s group buying websites are facing some chilly headwinds.Gaopeng.com, a joint venture between Groupon and China’s Internet giant Tencent,展开更多
Shi Zhongpeng is going to die today.If he's lucky,he may die more than once.In the morning,he could be hit by a sniper.In the afternoon,he might perish in a storm of quickly-shot arrows along with a dozen of his b...Shi Zhongpeng is going to die today.If he's lucky,he may die more than once.In the morning,he could be hit by a sniper.In the afternoon,he might perish in a storm of quickly-shot arrows along with a dozen of his beige-uniformed colleagues.Before dinner,he could suffer any number of fates,from getting his heart pulled out of his chest to a well-thrown hand grenade taking down his prop-plane fighter...展开更多
文摘A newlywed farmer and his wife were visitedby her mother,who immediately demanded aninspection of the place.The farmer had genuinelytried to be friendly to his new mother-in-law,hopingthat it could be a friendly,non-antagonistic(非对抗性的)relationship.All to no avail though,as shekept nagging(不断的唠叨)them at every opportunity,demanding changes,offering unwanted advice,
基金This work was supported by the National Natural Science FoundationShanghai Bao Steel Group of China under Grant No.50374028Doctor Foundation.
文摘The effects of an electric field on AIN precipitation and recrystallization texture were investigated. Cold-rolled 08Al killed steel sheets were annealed at 550℃ according to the two-step processes, for various maintaining times, with and without applying an electric field. It was found that the electric field promotes the precipitation of the second phase (AlN particles), strengthens the γ-fiber and weakens the α-fiber texture component in the recrystallized specimens. A possible explanation for the reinforcement of γ-fiber texture by the electric field is that the second phase AIN particle promotes the growth of γ-fiber at the expense of differently oriented grains.
文摘Aluminum killed cold rolled steel used for automobiles was welded in this paper by using CO 2 laser with wavelength 10.6μm.The experiment shows that high quality of welding can be realized at welding speed of 4 500mm/min by optimizing the parameters.The strength and hardness of laser welded joints for aluminum killed cold rolled steel increased compared to those of the base metal while the formability decreased.Forming limit diagram of joint material indicated that the laser weld seam should avoid the maximum deformation area of automobile parts during the designing period for the position of weld seam.
文摘In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Probe Microanalysis) and by analyzing the total oxygen. The results showed that in the slabs the total oxygen was quite low and the inclusions discovered were mainly small-sized angular alumina inclusions. This indicates that most inclusions have been removed by floating out during the continuous casting process. In addition, the countermeasures were discussed to decrease the alumina inclusions in the slabs further.
文摘In this study, the intercritical annealing process for a typical low-carbon aluminum killed steel is investigated. A cold-rolled sheet was annealed at intercfitical temperatures ranging from 730 ℃ to 770 ℃ and then cooled in air or water. The annealed steel was then baked at 210 ℃, and its mechanical properties and microstructures were analyzed in detail. It is shown that after the air-cooling process,the strength of steel decreased and ductility increased with an increase in the annealing temperature. However, after water-cooling, the strength and ductility both increased with the increase of annealing temperature. These results are attributed to the property- optimization of the steel.
文摘我们初次见到谚语Care killed a(the) cat,也许会莫明这“忧虑杀死猫”之奥妙。甚至看到辞书对此的中译——“忧虑伤人”,也未必能将两者挂钩。这里涉及到我们对该谚语的文化历史背景了解的问题。 Care killed a(the)cat源于莎士比亚《捕风捉影》一剧的第五幕第一场。该谚语与A cat has nine lives (猫有九条命)这条谚语有密切的关系。
文摘Background: We previously showed that treatment with Mycobacterium bovis BCG killed by extended freeze-drying (EFD BCG) modulates inflammation through regulatory T cells (Tregs) in an acute asthma model. In this study, we investigated the kinetics of Treg induction as well as their long-term homing in spleen and lungs correlating with reduced airway hyperresponsiveness (AHR) in a murine model of acute allergic asthma. We then evaluated the therapeutic implication of EFD BCG in a chronic asthma model. Methods: Tregs expressing Foxp3 were analyzed in various organs shortly and long-term after EFD BCG, live- and Heat Killed-(HK-) BCG treatments in an acute model of asthma. We further studied EFD BCG treatment on airway inflammation using a chronic model of asthma in mice. Results: Foxp3 expression peaked in the inguinal draining lymph-nodes (iDLNs) 2-4 days after EFD BCG treatment whereas it was long-term observed in spleen (days 7 to 90). This increase in Foxp3 expression was also found in lungs upon intranasal ovalbumin (OVA) challenge in OVA-sensitized mice. The loss of protection 4 months after EFD BCG treatment was correlated with the end of this phenomenon. Moreover, major lung inflammation hallmarks of severe asthma after multiple allergen challenges promoting chronic airway inflammation in OVA sensitized mice were reduced by EFD BCG treatment: AHR, eosinophils and neutrophils in bronchoalveolar lavage (BAL), mucus metaplasia, Th2 as well as Th17 cytokine levels in BAL and sera. EFD BCG treatment also enhances PPAR-γ expression and regulates NF-κBp65 translocation in lung extracts in this model of chronic asthma. Conclusions: EFD BCG treatment induced long-term protective effect associated to Foxp3 Tregs in the spleen and lungs in an acute model of asthma and inhibits AHR in a chronic model of asthma. EFD BCG could be a new and promising immuno-modulatory alternative treatment to corticoids in severe human asthma.
文摘The continuous annealing process of a typical aluminum killed steel was investigated. A cold rolled sheet was annealed continuously at holding temperature ranging from 580 to 760 ℃. The microstructures were analyzed in detail based on contiuous cooling transformation( CCT) curves that were simulated with JM artP ro softw are. The results show ed that recrystallization and perlitic transformations caused a diversity of microstructures and mechanical properties. In comparison with annealed steel that was produced from insufficient recrystallization,annealed steel produced from sufficient recrystallization had more isometric grains and exhibited low er strength and higher ductility. Higher annealing temperatures than A_1 provided steel with lamellar pearlite zones,large ferrite grains,low strength,and high ductility. The results are attributed to the property optimization of the steel.
文摘1.In the 40 meters deep of an ocean. there is an underwater creature institute (研究所).There the researchers(研究员) observe the way of life of dolphins (海豚 and whales(鲸鱼).
文摘Violence in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region, has left at least three civilians and an armed police officer dead on Sunday (July 5), sources with the regional government said early Monday.
文摘EDITOR’S NOTE:on January 3, 1991, when the worldwas Still immersed in the New Y6ar celebrstions, 17 Chineseand Japanese mountaineers, climbing the Meili Mountain atthe juncture Of "bet and Yunnan, were report6d missing. BothChinese and Japanese forces tried in vain to organized a rescue. But in July 1997, the bodies of the missing mountaineerswere found tragically killed by an avalanche. In China’s Tibet,detailed reports have been carried out by Mr. Zhou Zhen(issue No.4, 1997), the first-generstion mountaineer of Chinaand now professor with the PE Science Research Institute ofthe State Physical Education General Administrstion. The following is an abstract from Mr. Zhou Zhen’s latest report.
基金Sponsored by National Natural Science Foundation of China(51104109)
文摘Titanium is the impurity in some special steel grades.The existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various properties.Thus,titanium should be removed to the minimum.Based on the industrial production of ultra low carbon Al-Si killed steel,the physical-chemical behavior of titanium was investigated in vacuum degassing refining(RH)process with and without desulfurization.The influences of titanium content in hot metal,ladle slag composition,and ladle slag quantity,etc,on titanium content of refined liquid steel were discussed.The results showed that the partition ratio of titanium between ladle slag and liquid steel is in inverse proportion to the 4/3square of aluminum content.The maximum partition ratio of titanium between top slag and liquid steel can be obtained by adjusting an optimum slag composition including contents of FeOxand Al2O3and the slag basicity,and the suitable range of them should be controlled higher than 6%,less than 20%,and within 1.5to 3.0,respectively.Moreover,desulfurization refining by RH decreases the partition ratio of titanium between ladle slag and liquid steel significantly.To ensure the titanium content stably less than 15×10-6 in a 300tladle,the titanium content in hot metal must be less than 500×10-6 and the thickness of basic oxygen furnace(BOF)slag carrying over must be less than 50mm.
文摘The equilibrium problem of Green potentials for the Brownian motion has attracted general attention. The existence of equilibrium measure μ_B is proved, and the fundamental relation between the potential kernel u(x, y), the last exit time γ_B of B and the equilibrium measure μ_B, is given in (5) for the killed Markov processes.
基金supported by National Natural Science Foundation of China(Grant No. 10971253)
文摘In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expansion for the transition density, we prove the existence and uniqueness of both quasi-stationary distribution (qsd) and mean ratio quasi-stationary distribution (mrqsd). The later is shown to be closely related to laws of large numbers (LLN) and to quasi-ergodicity. We further show that the mrqsd is the unique stationary distribution of a certain limiting ergodic diffusion process of the BM conditioned on not having been killed. We also show that a phase transition occurs from mrqsd to qsd. On the other hand, we study the large deviation behavior related to the above problems. A key observation is that the mrqsd is the unique minimum of certain large deviation rate function. We further prove that the limiting diffusion process also satisfies a large deviation principle with the rate function attaining its unique minimum at the mrqsd. These give interpretations of the mrqsd from different points of view, and establish some intrinsic connections among the above topics. Some general results concerning Yaglom limit, moment convergence and LLN are also obtained.
文摘China-based websites mimicking the Groupon model fight for survival in a vicious, overcrowded market After a year of reckless expansion,China’s group buying websites are facing some chilly headwinds.Gaopeng.com, a joint venture between Groupon and China’s Internet giant Tencent,
文摘Shi Zhongpeng is going to die today.If he's lucky,he may die more than once.In the morning,he could be hit by a sniper.In the afternoon,he might perish in a storm of quickly-shot arrows along with a dozen of his beige-uniformed colleagues.Before dinner,he could suffer any number of fates,from getting his heart pulled out of his chest to a well-thrown hand grenade taking down his prop-plane fighter...