The renormalization of pion-exchange nucleon self-energy in nuclear matter is doneby dispersion relation.The exchange and correlation energies(in the ring approximation)ofpion,σ and ω mesons are derived and used to ...The renormalization of pion-exchange nucleon self-energy in nuclear matter is doneby dispersion relation.The exchange and correlation energies(in the ring approximation)ofpion,σ and ω mesons are derived and used to calculate the binding energy of nuctear matter atzero temperature.We find that the pionic contribution to the binding energy fails to lift the highdensity end of the binding energy curve,that is,the binding energy can not saturate without adensity dependent correction to the σNN and ωNN coupling constants.But the binding energycan saturate in the relativistic Hartree approximation plus the exchange and correlation energiesof л meson.展开更多
进一步将二阶Morita Context环上的部分性质推广到了三阶Morita Context环上.设O=[R C E A S F B D T]是三阶Morita Context环,证明了:1)O是π-正则的(或半Clean的、Exchange的、Potent的、GM-环)当且仅当R、S和T也是该类环;2)O是左Morp...进一步将二阶Morita Context环上的部分性质推广到了三阶Morita Context环上.设O=[R C E A S F B D T]是三阶Morita Context环,证明了:1)O是π-正则的(或半Clean的、Exchange的、Potent的、GM-环)当且仅当R、S和T也是该类环;2)O是左Morphic环当且仅当R、S、T是左Morphic的,且A=B=C=D=E=F=0.展开更多
In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantag...In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantages of an electric locomotive with the lower infrastructure costs of a diesel-electric locomotive. In this paper, the investigation status and the development trend of the fuel-cell-driven shunting locomotive were introduced. Through innovation of the power system using fuel cells, an experiment prototype of a fuel-cell shunting locomotive was developed, which would reduce the effects on the environment of the existing locomotives. This was the first locomotive to use a proton exchange membrane fuel-cell （PEMFC） power plant in China. From October 2012, we started to test the fuel-cell power plant and further test runs on the test rail-line in Chengdu, Sichuan. The achieved encouraging results can provide fundamental data for the modification of the current individual fuel cell locomotives or further development of the fuel-cell hybrid ones in China.展开更多
A novel stationary phase for weak cation exchange （WCX） chromatography was prepared by ＂grafting from＂ strategy. Surface initiated atom transfer radical polymerization （ATRP） of acrylic acid （AA） was conducted...A novel stationary phase for weak cation exchange （WCX） chromatography was prepared by ＂grafting from＂ strategy. Surface initiated atom transfer radical polymerization （ATRP） of acrylic acid （AA） was conducted in toluene medium, starting from the macromolecule initiators of poly（4-vinylbenzyl chloride-co-divinylbenzene） （PcMs/DvB） beads, The amounts of poly（acrylic acid） grafted chains with different ATRP formulations were calculated based on the elemental analyses. The poly（acrylic acid） grafted beads obtained with different ATRP formula- tions were tried as chromatographic packings in the separation of proteins by ion-exchange chromatography. The effect of the poly（acrylic acid） grafted chain lengths on PCMS/DVB beads for the separation of proteins was investigated in details. Simultaneously, characterization of the column was investigated as ion chromatographic stationary phase for the separation of inorganic cations. The results show that poly（acrylic acid） grafted columns had excellent performance for separation of proteins and inorganic cations. The highest of the dynamic capacity of the column was 35.55 mg/mL. The columns were provided with high column efficiency.展开更多
The direct iodination of polyfluorinated vinyl stannanes by tin-iodine exchange methodology was achieved giving （Z）-α-fluoro-β-trifluoromethyl vinyl iodides stereospecifically. Changing the substituent in R group ...The direct iodination of polyfluorinated vinyl stannanes by tin-iodine exchange methodology was achieved giving （Z）-α-fluoro-β-trifluoromethyl vinyl iodides stereospecifically. Changing the substituent in R group from the electron-withdrawing group to electron-donating group led to an increase in the yield from 78% to 90%, while it was moved from para to meta position the reaction did not afford a dramatic change in the yield （90% to 95%）. In addition, this reaction also can be applied to the vinyl stannane with heterocyclic group. The further coupling reaction of prepared vinyl iodide containing heterocyclic moiety with （Z）-α-fluoro-β-trifluoromethylstannanes gave polyfluorinated heterocyclic alkadienes with 2E,4E-selectivity.展开更多
The electronic structure and magnetism of compound Nd\-2Fe 17 N\-3 has been studied with MS_Xα method. It was found that there are negative exchange couplings between Fe(f) and Fe(c) atoms in Nd\-2Fe 17 N x compounds...The electronic structure and magnetism of compound Nd\-2Fe 17 N\-3 has been studied with MS_Xα method. It was found that there are negative exchange couplings between Fe(f) and Fe(c) atoms in Nd\-2Fe 17 N x compounds. The interstitial N atoms make the unit cell volume of the compounds increase a little, and hence the strength of negative exchange coupling decreases.展开更多
基金The project supported by the National Natural Scicnce Foundation of China
文摘The renormalization of pion-exchange nucleon self-energy in nuclear matter is doneby dispersion relation.The exchange and correlation energies(in the ring approximation)ofpion,σ and ω mesons are derived and used to calculate the binding energy of nuctear matter atzero temperature.We find that the pionic contribution to the binding energy fails to lift the highdensity end of the binding energy curve,that is,the binding energy can not saturate without adensity dependent correction to the σNN and ωNN coupling constants.But the binding energycan saturate in the relativistic Hartree approximation plus the exchange and correlation energiesof л meson.
文摘进一步将二阶Morita Context环上的部分性质推广到了三阶Morita Context环上.设O=[R C E A S F B D T]是三阶Morita Context环,证明了:1)O是π-正则的(或半Clean的、Exchange的、Potent的、GM-环)当且仅当R、S和T也是该类环;2)O是左Morphic环当且仅当R、S、T是左Morphic的,且A=B=C=D=E=F=0.
基金supported by the National Natural Science Foundation of China (51177138)the Specialized Research Fund for the Doctoral Program of Higher Education (20100184110015)+3 种基金the International Science and Technology Cooperation and Exchange Research Plan of Sichuan Province (2012HH0007)the Science and Technology Development Plan of Ministry of Railways (2012J012-D)the Fundamental Research Funds for the Central Universities (SWJTU11CX030)the Specialized Research Fund for the Doctoral Program of Higher Education (20120184120011)
文摘In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantages of an electric locomotive with the lower infrastructure costs of a diesel-electric locomotive. In this paper, the investigation status and the development trend of the fuel-cell-driven shunting locomotive were introduced. Through innovation of the power system using fuel cells, an experiment prototype of a fuel-cell shunting locomotive was developed, which would reduce the effects on the environment of the existing locomotives. This was the first locomotive to use a proton exchange membrane fuel-cell （PEMFC） power plant in China. From October 2012, we started to test the fuel-cell power plant and further test runs on the test rail-line in Chengdu, Sichuan. The achieved encouraging results can provide fundamental data for the modification of the current individual fuel cell locomotives or further development of the fuel-cell hybrid ones in China.
基金Project supported by the Foundation of the Ministery of Science and Technology of China （No. 2009CB626608） and the National Natural Science Foundation of China （No. 201065008）.
文摘A novel stationary phase for weak cation exchange （WCX） chromatography was prepared by ＂grafting from＂ strategy. Surface initiated atom transfer radical polymerization （ATRP） of acrylic acid （AA） was conducted in toluene medium, starting from the macromolecule initiators of poly（4-vinylbenzyl chloride-co-divinylbenzene） （PcMs/DvB） beads, The amounts of poly（acrylic acid） grafted chains with different ATRP formulations were calculated based on the elemental analyses. The poly（acrylic acid） grafted beads obtained with different ATRP formula- tions were tried as chromatographic packings in the separation of proteins by ion-exchange chromatography. The effect of the poly（acrylic acid） grafted chain lengths on PCMS/DVB beads for the separation of proteins was investigated in details. Simultaneously, characterization of the column was investigated as ion chromatographic stationary phase for the separation of inorganic cations. The results show that poly（acrylic acid） grafted columns had excellent performance for separation of proteins and inorganic cations. The highest of the dynamic capacity of the column was 35.55 mg/mL. The columns were provided with high column efficiency.
文摘The direct iodination of polyfluorinated vinyl stannanes by tin-iodine exchange methodology was achieved giving （Z）-α-fluoro-β-trifluoromethyl vinyl iodides stereospecifically. Changing the substituent in R group from the electron-withdrawing group to electron-donating group led to an increase in the yield from 78% to 90%, while it was moved from para to meta position the reaction did not afford a dramatic change in the yield （90% to 95%）. In addition, this reaction also can be applied to the vinyl stannane with heterocyclic group. The further coupling reaction of prepared vinyl iodide containing heterocyclic moiety with （Z）-α-fluoro-β-trifluoromethylstannanes gave polyfluorinated heterocyclic alkadienes with 2E,4E-selectivity.
文摘The electronic structure and magnetism of compound Nd\-2Fe 17 N\-3 has been studied with MS_Xα method. It was found that there are negative exchange couplings between Fe(f) and Fe(c) atoms in Nd\-2Fe 17 N x compounds. The interstitial N atoms make the unit cell volume of the compounds increase a little, and hence the strength of negative exchange coupling decreases.
