The angular spectrum of spontaneous emission in a two-dimensional undulator free-electron laser is analyzed theoretically. Numerical calculation shows that the 3-th harmonic spontaneous emission power density can be g...The angular spectrum of spontaneous emission in a two-dimensional undulator free-electron laser is analyzed theoretically. Numerical calculation shows that the 3-th harmonic spontaneous emission power density can be greatly enhanced by using a two-dimensional undulator, for which l=s, so the harmonic number can be selected by selecting l. Therefore, the higher harmonic operation of a free-electron laser can be realized selectively.展开更多
This paper introduces a new three dimensional autonomous system with five equilibrium points. It demonstrates complex chaotic behaviours within a wide range of parameters, which are described by phase portraits, Lyapu...This paper introduces a new three dimensional autonomous system with five equilibrium points. It demonstrates complex chaotic behaviours within a wide range of parameters, which are described by phase portraits, Lyapunov exponents, frequency spectrum, etc. Analysis of the bifurcation and Poincar@ map is used to reveal mechanisms of generating these complicated phenomena. The corresponding electronic circuits are designed, exhibiting experimental chaotic attractors in accord with numerical simulations. Since frequency spectrum analysis shows a broad frequency bandwidth, this system has perspective of potential applications in such engineering fields as secure communication.展开更多
A new copper(Ⅱ) complex [Cu(PDA)(H 2O) 2] was synthesized and its structure was determined. Cu(Ⅱ) is five coordinated in a tetragonal pyramid geometry. The two coordinating water molecules are different and t...A new copper(Ⅱ) complex [Cu(PDA)(H 2O) 2] was synthesized and its structure was determined. Cu(Ⅱ) is five coordinated in a tetragonal pyramid geometry. The two coordinating water molecules are different and the two Cu-O bond lengths differ by nearly 0.02 nm. The whole crystal is linked to form a three dimensional network by means of hydrogen bonds. The X band ESR spectrum shows three different g tensors with a well resolved hyperfine structure in the g z signal, giving the ESR parameters g x=2 05, g y =2 065 and g z =2 29. The covalency of the coordinate bonds and the deviation from tetragonal pyramid geometry for the complex are discussed based on the ESR spectra.展开更多
In this study, we selected adult normal pituitary gland tissues from six patients during operations for pituitary microadenomas via the transsphenoidal approach for extended normal pituitary tissue resection around th...In this study, we selected adult normal pituitary gland tissues from six patients during operations for pituitary microadenomas via the transsphenoidal approach for extended normal pituitary tissue resection around the tumor, and analyzed the protein expression of human normal pituitary using two-dimensional high-performance liquid chromatography combined with LTQ-Orbitrap mass spectrometry proteomics technology. The ten most highly expressed proteins in normal human pituitary were： alpha 3 type VI collagen isoform 5 precursor （abundance among tall pituitary proteins 1.30%）, fibrinogen beta chain preproprotein （0.99%）, vimentin （0.73%）, prolactin （0.69%）, ATP synthase, H~ transporting and mitochondrial F1 complex beta subunit precursor （0.52%）, keratin I （0.49%）, growth hormone （0.45%）, carbonic anhydrase I （0.40%）, heat shock protein 90 kDa I （0.31%）, and annexin V （0.30%）. Based on the biological function classifications of these proteins, the top three categories by content were neuroendocrine proteins （abundance among all pituitary proteins, 40.1%）, catalytic and metabolic proteins （28.3%）, and cell signal transduction proteins （9.8%）. Based on cell positioning classification, the top three categories were cell organelle （24.5%） membrane （20.8%）, and cytoplasm （13.0%）. Based on biological process classification, the top three categories of proteins are involved in physiological processes （42.9%）, cellular processes （40.4%）, and regulation of biological processes （9.1%）. Our experimental findings indicate that a protein expression profile database of normal human pituitary can be precisely and efficiently established by proteomics technology.展开更多
In this paper,the results of spectral description and invertibility of upper triangle infinite-dimensionalHamiltonian operators with a diagonal domain are given.By the above results,it is proved that the infinite-dime...In this paper,the results of spectral description and invertibility of upper triangle infinite-dimensionalHamiltonian operators with a diagonal domain are given.By the above results,it is proved that the infinite-dimensionalHamiltonian operator associated with plane elasticity equations without the body force is invertible,and the spectrumof which is non-empty and is a subset of R.展开更多
We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under differen...We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.展开更多
A theory of triple magnetopolarons in an isolated quantum well in a strong magnetic field was developed. We study the behavior of the magnetooptical absorption peaks corresponding to the transitions of an electron at ...A theory of triple magnetopolarons in an isolated quantum well in a strong magnetic field was developed. We study the behavior of the magnetooptical absorption peaks corresponding to the transitions of an electron at the Landau level with quantum numbers n ≥ 2. For n = 2 at the point of equality of cyclotron frequency and the frequency of optical phonon (LO), there is a cross of three terms of the electron-phonon system (the electron at the Landau level n = 2, the electron at n = 1, and the optical phonon and electron at n = 0 and two phonons), considered as a function of the cyclotron frequency. Interaction with phonons takes off the degeneracy of the terms and leads to three disjoint branches of the electron-phonon spectrum. The theory predicts that in the resonant magnetic field, the peak of magnetooptical absorption splits into three peaks, the intensity and position of which are dependent in a complex way on the magnitude of the magnetic field and the constant of the electron-phonon coupling.展开更多
文摘The angular spectrum of spontaneous emission in a two-dimensional undulator free-electron laser is analyzed theoretically. Numerical calculation shows that the 3-th harmonic spontaneous emission power density can be greatly enhanced by using a two-dimensional undulator, for which l=s, so the harmonic number can be selected by selecting l. Therefore, the higher harmonic operation of a free-electron laser can be realized selectively.
基金supported by the National Natural Science Foundation of China (Grant No. 10771088)Natural Science Foundation of Jiangsu Province,China (Grant No. 2007098)+3 种基金Outstanding Personnel Program in Six Fields of Jiangsu Province,China (Grant No. 6-A-029)National Natural Science (Youth) Foundation of China (Grant No. 10801140)Youth Foundation of Chongqing Normal University,China (Grant No. 08XLQ04)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 09B 202Z)
文摘This paper introduces a new three dimensional autonomous system with five equilibrium points. It demonstrates complex chaotic behaviours within a wide range of parameters, which are described by phase portraits, Lyapunov exponents, frequency spectrum, etc. Analysis of the bifurcation and Poincar@ map is used to reveal mechanisms of generating these complicated phenomena. The corresponding electronic circuits are designed, exhibiting experimental chaotic attractors in accord with numerical simulations. Since frequency spectrum analysis shows a broad frequency bandwidth, this system has perspective of potential applications in such engineering fields as secure communication.
基金Supported by the National Natural Science Foundation of China(No.2 0 0 710 192 0 0 710 2 0 and5 0 172 0 2 ) and the Re-search Fund for Doctoral Program of Higher Education.
文摘A new copper(Ⅱ) complex [Cu(PDA)(H 2O) 2] was synthesized and its structure was determined. Cu(Ⅱ) is five coordinated in a tetragonal pyramid geometry. The two coordinating water molecules are different and the two Cu-O bond lengths differ by nearly 0.02 nm. The whole crystal is linked to form a three dimensional network by means of hydrogen bonds. The X band ESR spectrum shows three different g tensors with a well resolved hyperfine structure in the g z signal, giving the ESR parameters g x=2 05, g y =2 065 and g z =2 29. The covalency of the coordinate bonds and the deviation from tetragonal pyramid geometry for the complex are discussed based on the ESR spectra.
基金supported by the National NaturalScience Foundation of China, No. 81200890
文摘In this study, we selected adult normal pituitary gland tissues from six patients during operations for pituitary microadenomas via the transsphenoidal approach for extended normal pituitary tissue resection around the tumor, and analyzed the protein expression of human normal pituitary using two-dimensional high-performance liquid chromatography combined with LTQ-Orbitrap mass spectrometry proteomics technology. The ten most highly expressed proteins in normal human pituitary were： alpha 3 type VI collagen isoform 5 precursor （abundance among tall pituitary proteins 1.30%）, fibrinogen beta chain preproprotein （0.99%）, vimentin （0.73%）, prolactin （0.69%）, ATP synthase, H~ transporting and mitochondrial F1 complex beta subunit precursor （0.52%）, keratin I （0.49%）, growth hormone （0.45%）, carbonic anhydrase I （0.40%）, heat shock protein 90 kDa I （0.31%）, and annexin V （0.30%）. Based on the biological function classifications of these proteins, the top three categories by content were neuroendocrine proteins （abundance among all pituitary proteins, 40.1%）, catalytic and metabolic proteins （28.3%）, and cell signal transduction proteins （9.8%）. Based on cell positioning classification, the top three categories were cell organelle （24.5%） membrane （20.8%）, and cytoplasm （13.0%）. Based on biological process classification, the top three categories of proteins are involved in physiological processes （42.9%）, cellular processes （40.4%）, and regulation of biological processes （9.1%）. Our experimental findings indicate that a protein expression profile database of normal human pituitary can be precisely and efficiently established by proteomics technology.
基金the National Natural Science Foundation of China under Grant No.10562002the Natural Science Foundation of Inner Mongolia under Grant No.200508010103
文摘In this paper,the results of spectral description and invertibility of upper triangle infinite-dimensionalHamiltonian operators with a diagonal domain are given.By the above results,it is proved that the infinite-dimensionalHamiltonian operator associated with plane elasticity equations without the body force is invertible,and the spectrumof which is non-empty and is a subset of R.
文摘We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.
文摘A theory of triple magnetopolarons in an isolated quantum well in a strong magnetic field was developed. We study the behavior of the magnetooptical absorption peaks corresponding to the transitions of an electron at the Landau level with quantum numbers n ≥ 2. For n = 2 at the point of equality of cyclotron frequency and the frequency of optical phonon (LO), there is a cross of three terms of the electron-phonon system (the electron at the Landau level n = 2, the electron at n = 1, and the optical phonon and electron at n = 0 and two phonons), considered as a function of the cyclotron frequency. Interaction with phonons takes off the degeneracy of the terms and leads to three disjoint branches of the electron-phonon spectrum. The theory predicts that in the resonant magnetic field, the peak of magnetooptical absorption splits into three peaks, the intensity and position of which are dependent in a complex way on the magnitude of the magnetic field and the constant of the electron-phonon coupling.
