Tongting coal(TTC) was exhaustively extracted with carbon disulfide and N-melthy-2-pyrolidinone(CS 2 /NMP) mixed solvents to afford brown particles of extract,which was characterized with proximate analyzer,transmissi...Tongting coal(TTC) was exhaustively extracted with carbon disulfide and N-melthy-2-pyrolidinone(CS 2 /NMP) mixed solvents to afford brown particles of extract,which was characterized with proximate analyzer,transmission electron microscope(TEM) and Fourier transform infrared(FTIR) spectrometer.The results show that the nanometer particles of extract,which were free of ash,are superfine and superclean with tract content of 0.02% A d and particles size of about 100-150 nm.TTC and extract were then subject to oxidation with H 2 O 2 and oxidation products were subsequently analyzed with FTIR and gas chromatography/mass spectrometer(GC/MS).The results show that extract is more reactive with H 2 O 2 in comparison to TTC and richer in oxygen-containing species including phenols,alcohols,ethers,esters,carboxylic acids and anhydrides.展开更多
When circularly polarized light travels through a ferrofluid film in the presence of an applied magnetic field, the transmitted light will behave as elliptically polarized light, because of magnetic birefringence and ...When circularly polarized light travels through a ferrofluid film in the presence of an applied magnetic field, the transmitted light will behave as elliptically polarized light, because of magnetic birefringence and dichroism. The angular distribution of the relative intensity of the transmitted light can be obtained using a polarizer, so that the ratio of both the long and short ax- es-as well as the orientation angle of the ellipse, corresponding to the direction of the applied magnetic field--can be deter- mined, and whether the ferrofluids samples are stable during the measurement can be directly judged from the shape of the distribution curves. Thus, the ratio of the amplitudes Ax/Ay and the added phase difference A r can be resolved in the elliptically polarized light, and information on both the magnetic birefringence An and the dichroism Ak can be deduced for the ferrofluid sample. From the orientation angles of both right-handed and left-handed elliptically polarized transmitted light, the direction of the applied magnetic field can be accurately determined. Using circularly polarized light, the magnetic birefringence and dichroism of pure γ-Fe2O3 ferrofluids and γ--Fe2O3/ZnFe2O4 binary ferrofluids were studied. For the binary ferrofluids, a mod- ulating effect on the magnetic birefringence and dichroism was revealed.展开更多
Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are...Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency （RF） field. Both electrom^gnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing.展开更多
基金subsidized by the National Natural Science Foundation of China (Nos.50474066,50874108 and 50921002)the Fundamental Research Funds for the Central Universities(No.2010LKHX01)the National Basic Research Program of China (No.2012CB214900)
文摘Tongting coal(TTC) was exhaustively extracted with carbon disulfide and N-melthy-2-pyrolidinone(CS 2 /NMP) mixed solvents to afford brown particles of extract,which was characterized with proximate analyzer,transmission electron microscope(TEM) and Fourier transform infrared(FTIR) spectrometer.The results show that the nanometer particles of extract,which were free of ash,are superfine and superclean with tract content of 0.02% A d and particles size of about 100-150 nm.TTC and extract were then subject to oxidation with H 2 O 2 and oxidation products were subsequently analyzed with FTIR and gas chromatography/mass spectrometer(GC/MS).The results show that extract is more reactive with H 2 O 2 in comparison to TTC and richer in oxygen-containing species including phenols,alcohols,ethers,esters,carboxylic acids and anhydrides.
基金supported by the National Natural Science Foundation of China (Grant No. 11074205)
文摘When circularly polarized light travels through a ferrofluid film in the presence of an applied magnetic field, the transmitted light will behave as elliptically polarized light, because of magnetic birefringence and dichroism. The angular distribution of the relative intensity of the transmitted light can be obtained using a polarizer, so that the ratio of both the long and short ax- es-as well as the orientation angle of the ellipse, corresponding to the direction of the applied magnetic field--can be deter- mined, and whether the ferrofluids samples are stable during the measurement can be directly judged from the shape of the distribution curves. Thus, the ratio of the amplitudes Ax/Ay and the added phase difference A r can be resolved in the elliptically polarized light, and information on both the magnetic birefringence An and the dichroism Ak can be deduced for the ferrofluid sample. From the orientation angles of both right-handed and left-handed elliptically polarized transmitted light, the direction of the applied magnetic field can be accurately determined. Using circularly polarized light, the magnetic birefringence and dichroism of pure γ-Fe2O3 ferrofluids and γ--Fe2O3/ZnFe2O4 binary ferrofluids were studied. For the binary ferrofluids, a mod- ulating effect on the magnetic birefringence and dichroism was revealed.
基金Supported by the Science Foundation of Guizhou Province under Grant Nos.LKM(2013)19 and (2014)2090
文摘Electromagnetically induced transparency and absorption of a monochromatic light controlled by a radio frequency field in the cold multi-Zeeman-sublevel atoms are theoretically investigated. These Zeeman sublevels are coupled by a radio frequency （RF） field. Both electrom^gnetically induced transparency and electromagnetically induced absorption can be obtained by tuning the frequency of RF field for both the linear polarization and elliptical polarization monochromatic lights. When the transfer of coherence via spontaneous emission from the excited state to the ground state is considered, electromagnetically induced absorption can be changed into electromagnetically induced transparency with the change of intensity of radio field. The transparency windows controlled by the RF field can have potential applications in the magnetic-field measurement and quantum information processing.
