The removal of boron from metallurgical silicon in slag system of CaO-SiO2-10%CaF2 was investigated. The partition coefficient of boron （LB） between slag and silicon phase was studied under different conditions of s...The removal of boron from metallurgical silicon in slag system of CaO-SiO2-10%CaF2 was investigated. The partition coefficient of boron （LB） between slag and silicon phase was studied under different conditions of slag basicity （CaO/SiO2 ratio）, temperature, mass ratio of slag to silicon and gas blowing. The results show that LB has a maximum value of 4.61 when the CaO/SiO2 mass ratio is around 2 at l 873 K. The logarithm of LB is linear to the reciprocal of temperatures in the range of 1 773-1 973 K. LB increases with the increase of mass ratio of slag to silicon, but it does not increase markedly when the ratio excesses 3. Gas blowing can sionificantlv increase the removal of boron, and LR increases with the increase of water vapor content.展开更多
According to the development status of Chinese listed companies, it is important to implement a stock option incentive plan for the top executives (TE) of the companies. It is necessary to establish a set of indices t...According to the development status of Chinese listed companies, it is important to implement a stock option incentive plan for the top executives (TE) of the companies. It is necessary to establish a set of indices to evaluate a top executive’s performance and award performance-based stock options to them scientifically and reasonably. This thesis sets indices from the perspective of the top executive’s behaviour and results, which differs from the traditional methods performance evaluation.展开更多
Pure CaB6single crystals are synthesized under high pressure (1 GPa) and temperature (1050°C). The temperature-dependenceof electric resistivity and Hall coefficient from 2 to 300 K shows that the CaB6single crys...Pure CaB6single crystals are synthesized under high pressure (1 GPa) and temperature (1050°C). The temperature-dependenceof electric resistivity and Hall coefficient from 2 to 300 K shows that the CaB6single crystals are conductors withsemi-metallic behavior and electron carriers. Band structure calculations indicate that the conduction and valence bands meetat the X point at the Fermi level, which is consistent with the experimentally determined conducting behavior of CaB6singlecrystals. Calculations of state density suggest that the states at the Fermi level originate from the 2p orbital of the B atoms andthe 3d orbital of the Ca atom. Magnetization measurements show the paramagnetic nature of the CaB6. The micro-hardness ofCaB6is 24.39 GPa, and the Raman spectra of CaB6yield three sharp peaks at around 780.9, 1138.9, and 1282.1 cm 1for T2g,Eg, and A1g, respectively. The specific heat of the crystal is measured and found to be well described by the Debye and Einsteincombined model. The fitting results show Debye and Einstein temperatures are 1119 and 199 K, respectively.展开更多
In this paper,we study the effect of spontaneously generated coherence(SGC) on transient evolution of gain without inversion(GWI) in a Doppler broadened quasi Λ-type four-level atomic system.It is shown that transien...In this paper,we study the effect of spontaneously generated coherence(SGC) on transient evolution of gain without inversion(GWI) in a Doppler broadened quasi Λ-type four-level atomic system.It is shown that transient evolution of GWI is very sensitive to the variation of SGC strength,and the transient maximum value and steady value of GWI both increase with SGC strength increasing.The transient and steady values of GWI with SGC are much larger than those without SGC.When Doppler broadening is present,the transient maximum value and steady value of GWI first increase and then decrease with Doppler broadening width(D) increasing,and the value of D which corresponds to the maximum transient GWI is different from that corresponding to the maximum steady GWI.The time needed for reaching the steady GWI increases with D increasing.The steady GWI,which is larger than that without Doppler broadening(D = 0),can be obtained by choosing appropriate D and SGC strength.展开更多
基金Project(2007J0012)supported by the Natural Science Foundation of Fujian Province,ChinaProject(2007HZ0005-2)supported by the Key Technological Program of Fujian Province,China
文摘The removal of boron from metallurgical silicon in slag system of CaO-SiO2-10%CaF2 was investigated. The partition coefficient of boron （LB） between slag and silicon phase was studied under different conditions of slag basicity （CaO/SiO2 ratio）, temperature, mass ratio of slag to silicon and gas blowing. The results show that LB has a maximum value of 4.61 when the CaO/SiO2 mass ratio is around 2 at l 873 K. The logarithm of LB is linear to the reciprocal of temperatures in the range of 1 773-1 973 K. LB increases with the increase of mass ratio of slag to silicon, but it does not increase markedly when the ratio excesses 3. Gas blowing can sionificantlv increase the removal of boron, and LR increases with the increase of water vapor content.
文摘According to the development status of Chinese listed companies, it is important to implement a stock option incentive plan for the top executives (TE) of the companies. It is necessary to establish a set of indices to evaluate a top executive’s performance and award performance-based stock options to them scientifically and reasonably. This thesis sets indices from the perspective of the top executive’s behaviour and results, which differs from the traditional methods performance evaluation.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51072174, 50772094 and 50821001)the NBRPC(Grant No. 2011CB808205)
文摘Pure CaB6single crystals are synthesized under high pressure (1 GPa) and temperature (1050°C). The temperature-dependenceof electric resistivity and Hall coefficient from 2 to 300 K shows that the CaB6single crystals are conductors withsemi-metallic behavior and electron carriers. Band structure calculations indicate that the conduction and valence bands meetat the X point at the Fermi level, which is consistent with the experimentally determined conducting behavior of CaB6singlecrystals. Calculations of state density suggest that the states at the Fermi level originate from the 2p orbital of the B atoms andthe 3d orbital of the Ca atom. Magnetization measurements show the paramagnetic nature of the CaB6. The micro-hardness ofCaB6is 24.39 GPa, and the Raman spectra of CaB6yield three sharp peaks at around 780.9, 1138.9, and 1282.1 cm 1for T2g,Eg, and A1g, respectively. The specific heat of the crystal is measured and found to be well described by the Debye and Einsteincombined model. The fitting results show Debye and Einstein temperatures are 1119 and 199 K, respectively.
基金supported by the National Natural Science Foundation of China (No.11175105)
文摘In this paper,we study the effect of spontaneously generated coherence(SGC) on transient evolution of gain without inversion(GWI) in a Doppler broadened quasi Λ-type four-level atomic system.It is shown that transient evolution of GWI is very sensitive to the variation of SGC strength,and the transient maximum value and steady value of GWI both increase with SGC strength increasing.The transient and steady values of GWI with SGC are much larger than those without SGC.When Doppler broadening is present,the transient maximum value and steady value of GWI first increase and then decrease with Doppler broadening width(D) increasing,and the value of D which corresponds to the maximum transient GWI is different from that corresponding to the maximum steady GWI.The time needed for reaching the steady GWI increases with D increasing.The steady GWI,which is larger than that without Doppler broadening(D = 0),can be obtained by choosing appropriate D and SGC strength.
