A simple recombinant PCR method was used to delete the dszB gene responsible for the slowest step of the Dsz pathway and allow the accumulation of hydroxyphenyl benzene sulfinate (HPBS) in the recombinant E. coli. Usi...A simple recombinant PCR method was used to delete the dszB gene responsible for the slowest step of the Dsz pathway and allow the accumulation of hydroxyphenyl benzene sulfinate (HPBS) in the recombinant E. coli. Using GC/MS, HPBS accumulation was confirmed. The recombinant E. coli could also desulfurize Cx-DBT to corresponding Cx-HPBS. The result gave a new insight to BDS process and explored a new method to obtain valuable surfactants from cheap raw materials.展开更多
Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory conditions. The fundamental research on a process of disassembling and recovering selected materials from Ni-C...Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory conditions. The fundamental research on a process of disassembling and recovering selected materials from Ni-Cd batterieswas conducted. The impacts of temperature, pressure and time were studied respectively. The mechanism of vacuum thermal recovering was also discussed. The results show that: Ni-Cd batteries can be recovered effectively byvacuum-aided recovering system at 573~1173 K. At constant pressure, the increase of temperature can improve theseparating efficiency of cadmium. When the temperature is 1173 K, the cadmium can evaporate completely fromthe residue during 3 h at 10 Pa. The reduction of pressure in the certain range is effective to separate cadmium byvacuum distillation. Distillation time is a very important factor affecting separation of cadmium.展开更多
The influences of Sn element and heat treat-ment on the microstructure and mechanical properties of Mg-7Al alloy prepared by vacuum die cast(VDC)were studied.The results indicate thatα-Mg dendrite and Mg_(17)Al_(12) ...The influences of Sn element and heat treat-ment on the microstructure and mechanical properties of Mg-7Al alloy prepared by vacuum die cast(VDC)were studied.The results indicate thatα-Mg dendrite and Mg_(17)Al_(12) are refined and new Mg_(2)Sn phase is formed in Mg-7Al alloy with 2 wt%Sn addition.The ultimate tensile strength(σ_(b))of Mg-7Al alloy increases from 205 to 258 MPa(i.e.,a 25%increase).The mechanical properties of Mg-7Al-2Sn(AT72)alloy are further improved through heat treatment because of the dense microstructures processed by VDC.In particular,the mechanical properties of AT72 alloy are greatly improved after solution treatment at 400℃for 20 h due to solution strengthening of Al and Sn elements and precipitation strengthening of Mg_(2)Sn phases.The precipitation strengthening effect of particle Mg_(2)Sn phases is more apparent due to the decomposition of Mg_(17)Al_(12) phases.In addition,from the view of microscopic theory,the effect of Sn on mechanical properties of Mg-7Al alloy was discussed by first-principle calculation.展开更多
文摘A simple recombinant PCR method was used to delete the dszB gene responsible for the slowest step of the Dsz pathway and allow the accumulation of hydroxyphenyl benzene sulfinate (HPBS) in the recombinant E. coli. Using GC/MS, HPBS accumulation was confirmed. The recombinant E. coli could also desulfurize Cx-DBT to corresponding Cx-HPBS. The result gave a new insight to BDS process and explored a new method to obtain valuable surfactants from cheap raw materials.
文摘Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory conditions. The fundamental research on a process of disassembling and recovering selected materials from Ni-Cd batterieswas conducted. The impacts of temperature, pressure and time were studied respectively. The mechanism of vacuum thermal recovering was also discussed. The results show that: Ni-Cd batteries can be recovered effectively byvacuum-aided recovering system at 573~1173 K. At constant pressure, the increase of temperature can improve theseparating efficiency of cadmium. When the temperature is 1173 K, the cadmium can evaporate completely fromthe residue during 3 h at 10 Pa. The reduction of pressure in the certain range is effective to separate cadmium byvacuum distillation. Distillation time is a very important factor affecting separation of cadmium.
基金financially supported by the Program for Liaoning Innovative Research Team in University (No. LT2013004)the Key Technologies Research and Development Program of Liaoning Province (No.2013201018)the Doctoral Starting up Foundation of Liaoning Province (No.20131083)
文摘The influences of Sn element and heat treat-ment on the microstructure and mechanical properties of Mg-7Al alloy prepared by vacuum die cast(VDC)were studied.The results indicate thatα-Mg dendrite and Mg_(17)Al_(12) are refined and new Mg_(2)Sn phase is formed in Mg-7Al alloy with 2 wt%Sn addition.The ultimate tensile strength(σ_(b))of Mg-7Al alloy increases from 205 to 258 MPa(i.e.,a 25%increase).The mechanical properties of Mg-7Al-2Sn(AT72)alloy are further improved through heat treatment because of the dense microstructures processed by VDC.In particular,the mechanical properties of AT72 alloy are greatly improved after solution treatment at 400℃for 20 h due to solution strengthening of Al and Sn elements and precipitation strengthening of Mg_(2)Sn phases.The precipitation strengthening effect of particle Mg_(2)Sn phases is more apparent due to the decomposition of Mg_(17)Al_(12) phases.In addition,from the view of microscopic theory,the effect of Sn on mechanical properties of Mg-7Al alloy was discussed by first-principle calculation.
