A method is presented to solve the characteristic impedance of transmission lines of specific cross-section. In this method, we use the circle or ellipse to approximate polygonal boundaries, taking account of ′angular effect′ of the electric charge of polygonal outer conductor, and take geometric mean of the upper and lower bounds to the size of the cross-section. The formulae for calculating the characteristic impedance of five new transmission lines (i.e. with rectangular outer and elliptic inner, circular outer and equilateral triangular inner, circular outer and regular pentagonal inner, circular outer and regular hexagonal inner, elliptic outer and rectangular inner cross sections respectively and nine existing transmission lines are obtained, all expressed in terms of elementary functions. The accuracy of the expressions is confirmed by comparing the numerical values obtained with exact values of same relative problems in the literatures.
A method is presented to solve the characteristic impedance of transmission lines of specific cross-section. In this method, we use the circle or ellipse to approximate polygonal boundaries, taking account of ′angular effect′ of the electric charge of polygonal outer conductor, and take geometric mean of the upper and lower bounds to the size of the cross-section. The formulae for calculating the characteristic impedance of five new transmission lines (i.e. with rectangular outer and elliptic inner, circular outer and equilateral triangular inner, circular outer and regular pentagonal inner, circular outer and regular hexagonal inner, elliptic outer and rectangular inner cross sections respectively and nine existing transmission lines are obtained, all expressed in terms of elementary functions. The accuracy of the expressions is confirmed by comparing the numerical values obtained with exact values of same relative problems in the literatures.
In this part, the third order radial ion trajectory and the second order axial ion trajectory for a crossed toroidal electric and inhomogeneous magnetic field are studied. The formulae for the third order trajectory and slope are derived, which cover most cases of sector fields and in special cases agree with those already presented by previous authors. Therefore, these results are general and may be of use in designing mass spectrometers. The effects of oblique entrance and exit, curved field boundary and fringing field have not been studied yet.
In this part, the third order radial ion trajectory and the second order axial ion trajectory for a crossed toroidal electric and inhomogeneous magnetic field are studied. The formulae for the third order trajectory and slope are derived, which cover most cases of sector fields and in special cases agree with those already presented by previous authors. Therefore, these results are general and may be of use in designing mass spectrometers. The effects of oblique entrance and exit, curved field boundary and fringing field have not been studied yet.
In this part, the ion optical theory for the third order trajectory in a crossed toroidal electric and inhomogeneous magnetic field is treated in detail. The transfer matrix are derived up to the third order. Consequently, for an ion optical system possessing the second and third order aberrations, the determinant of the transfer matrix is shown to be equal to 1. In order to transform the transfer matrix between different deviations the transform matrixes are derived. Some related equalities and corresponding relations for the elements of S and H matrixes are given. These results may be of use in designing mass spector meters.
In this part, the ion optical theory for the third order trajectory in a crossed toroidal electric and inhomogeneous magnetic field is treated in detail. The transfer matrix are derived up to the third order. Consequently, for an ion optical system possessing the second and third order aberrations, the determinant of the transfer matrix is shown to be equal to 1. In order to transform the transfer matrix between different deviations the transform matrixes are derived. Some related equalities and corresponding relations for the elements of S and H matrixes are given. These results may be of use in designing mass spector meters.
It is pointed out that by placing a Josephson tunnel junction in a cavity, which resonates with the supercurrent of the junction, i.e., when the Josephson frequency ω=2eV0/h is equal to one of the cavity frequencies ωr, and the cavity Q-value is sufficiently high, then the oscillating electric-magnetic field excited by the junction reacts on the junction itself and produces a supercurrent oscillation with the applied external flux. Its period can be much smaller than the magnetic flux quantum period φ0.
It is pointed out that by placing a Josephson tunnel junction in a cavity, which resonates with the supercurrent of the junction, i.e., when the Josephson frequency ω=2eV0/h is equal to one of the cavity frequencies ωr, and the cavity Q-value is sufficiently high, then the oscillating electric-magnetic field excited by the junction reacts on the junction itself and produces a supercurrent oscillation with the applied external flux. Its period can be much smaller than the magnetic flux quantum period φ0.
An apparatus is used in which the hysteresis loops of a transparent magnetic medium can be drawn. We measure the hysteresis loops of samples with various domain patterns, especially bubble lattice and strip domain patterns. The diffrences of these loops were noticed and interpreted qualitatively. From the results we comfirmed the conclusion given by Cape and Lehman that a magnetic film with the bubble lattice domain pattern is in a special 'remanence' state.
An apparatus is used in which the hysteresis loops of a transparent magnetic medium can be drawn. We measure the hysteresis loops of samples with various domain patterns, especially bubble lattice and strip domain patterns. The diffrences of these loops were noticed and interpreted qualitatively. From the results we comfirmed the conclusion given by Cape and Lehman that a magnetic film with the bubble lattice domain pattern is in a special 'remanence' state.
The time evolutions of dispersive diffusion-controlled processes are considered in the light of a waiting time distribution function. The predictions agree excellently with available experimental data.
The time evolutions of dispersive diffusion-controlled processes are considered in the light of a waiting time distribution function. The predictions agree excellently with available experimental data.
At temperatures of 10 K, 90 K and 300 K, the absorption spectra of YA1O3:Nd3+ are systematically examined in the region of 0.33-5.7 μm. The Stark's sub-levels by the action of the crystalline field are assigned. In addition, the temperature effect of a few spectra in the temperature range of 10-663 K are observed and some interesting results are obtained.
At temperatures of 10 K, 90 K and 300 K, the absorption spectra of YA1O3:Nd3+ are systematically examined in the region of 0.33-5.7 μm. The Stark's sub-levels by the action of the crystalline field are assigned. In addition, the temperature effect of a few spectra in the temperature range of 10-663 K are observed and some interesting results are obtained.
In this paper, the optical bistability in two-photon resonance media is discussed theoretically. The steady-state behavior in both the cases of two-photon far- and near-resonance, and the transient behavior in the case of two-photon near-resonance are analysed. The two-photon vector model is established and applied to the analyses. The corresponding characteristic curves in sodium vapour are given based or the result of numerical calculation.
In this paper, the optical bistability in two-photon resonance media is discussed theoretically. The steady-state behavior in both the cases of two-photon far- and near-resonance, and the transient behavior in the case of two-photon near-resonance are analysed. The two-photon vector model is established and applied to the analyses. The corresponding characteristic curves in sodium vapour are given based or the result of numerical calculation.
In this paper the behavior of degenerate four wave mixing and parameteric oscillation of backward wave under strong pumping condition is analysed theoretically. Considering the competing effect of Raman scattering, the dependence of intensity of parametric backward wave oscillation on the pumping intensity is obtained. The theoretical result agrees well with the experiment for nitrobenzene. The analysis also shows that the intensity of parametric oscillation is a multi-valued function of the pumping intensity due to the intensity-dependent attenuation coefficient.
In this paper the behavior of degenerate four wave mixing and parameteric oscillation of backward wave under strong pumping condition is analysed theoretically. Considering the competing effect of Raman scattering, the dependence of intensity of parametric backward wave oscillation on the pumping intensity is obtained. The theoretical result agrees well with the experiment for nitrobenzene. The analysis also shows that the intensity of parametric oscillation is a multi-valued function of the pumping intensity due to the intensity-dependent attenuation coefficient.
Internal friction of hydrogenated Ti, Ti-6A1-4V, Ti-5Al-2.5Sn and Ti-50Nb alloys in the range of 100 K to 350 K was measured. It was found that there was not only a known Snoek peak of hydrogen atoms in the β-phase, but also a new relaxation peak caused by the small amount of hydrogen atoms in the h.c.p. lattice α-phase. The mechanism, by which this new peak is produced, is suggested.
Internal friction of hydrogenated Ti, Ti-6A1-4V, Ti-5Al-2.5Sn and Ti-50Nb alloys in the range of 100 K to 350 K was measured. It was found that there was not only a known Snoek peak of hydrogen atoms in the β-phase, but also a new relaxation peak caused by the small amount of hydrogen atoms in the h.c.p. lattice α-phase. The mechanism, by which this new peak is produced, is suggested.
A phasediagram of the alloys of the dysprosium-copper binary system has been determined by means of X-ray diffraction and differential thermal analysis techniques. Its constitutional diagram has been constructed. Two eutectic reactions occur at 12 and 83 wt%Cu approximately, and with characteristic temperatures of 808 and 88°C, respectively. At room temperature three stable intermetallic compounds have been found, namely DyCu, DyCu2 and DyCu5. The DyCu and DyCu2 are formed by peritectic reactions at 840 and 885°C respectively, and DyCu5 melt congruently at 97°C. However, another intermetallic compound DyCur forms at 89°C periteetically and decomposes eutectoidally at 848°C as it is cooling slowly. The solid solubility of Dy in Cu is undetectable, and the solid solubility of Cu in Dy is less than 0.2 wt%Cu at room temperature.
A phasediagram of the alloys of the dysprosium-copper binary system has been determined by means of X-ray diffraction and differential thermal analysis techniques. Its constitutional diagram has been constructed. Two eutectic reactions occur at 12 and 83 wt%Cu approximately, and with characteristic temperatures of 808 and 88°C, respectively. At room temperature three stable intermetallic compounds have been found, namely DyCu, DyCu2 and DyCu5. The DyCu and DyCu2 are formed by peritectic reactions at 840 and 885°C respectively, and DyCu5 melt congruently at 97°C. However, another intermetallic compound DyCur forms at 89°C periteetically and decomposes eutectoidally at 848°C as it is cooling slowly. The solid solubility of Dy in Cu is undetectable, and the solid solubility of Cu in Dy is less than 0.2 wt%Cu at room temperature.
The ionic conductances of polycrystalline Rb4Cu16I7Cl13 for both porous and dense specimens have been measured between - 80-8°C under hydrostatic pressure from 0.5 to 11.6 kbar. A conductance maximum exists near 4-5 kbar on conductance versus pressure curve for porous specimens, while the conductance decreases with pressure for dense specimen. The temperature dependence of conductance under constant high pressure is the same as that under atmospheric pressure. The pressure does not obviously influence the a →β phase transition temperature. The activation volumes are 0.90 cm3/mol and 1.55 cm3/mol for α and β phase respectively.
The ionic conductances of polycrystalline Rb4Cu16I7Cl13 for both porous and dense specimens have been measured between - 80-8°C under hydrostatic pressure from 0.5 to 11.6 kbar. A conductance maximum exists near 4-5 kbar on conductance versus pressure curve for porous specimens, while the conductance decreases with pressure for dense specimen. The temperature dependence of conductance under constant high pressure is the same as that under atmospheric pressure. The pressure does not obviously influence the a →β phase transition temperature. The activation volumes are 0.90 cm3/mol and 1.55 cm3/mol for α and β phase respectively.
In this paper we presented our experimental results of in situ TEM observations of ferroelectric phase transitions in BaBa2NaNb5O15 (Tc =550℃) and LiTaO3 (TC = 660℃). At room temperature the domain patterns are of the scale 0.2-1 μm. Increasing the temperature to near Tc, the micro-domains forming quasi-regular arrays of the scale about several hundreds of angstroms have been observed and interpreted according to a model slightly modified from that of Селок. A strong susceptibility to radiation damage is found in LiTaO3 near phase transition temperature which may be connected with soft modes of phase transitions.
In this paper we presented our experimental results of in situ TEM observations of ferroelectric phase transitions in BaBa2NaNb5O15 (Tc =550℃) and LiTaO3 (TC = 660℃). At room temperature the domain patterns are of the scale 0.2-1 μm. Increasing the temperature to near Tc, the micro-domains forming quasi-regular arrays of the scale about several hundreds of angstroms have been observed and interpreted according to a model slightly modified from that of Селок. A strong susceptibility to radiation damage is found in LiTaO3 near phase transition temperature which may be connected with soft modes of phase transitions.
This compound (C22H18O2ClBr) is monoclinic, with space group P21/n and α = 19.502(10)?, b = 9.118(5)?, c = 11.233(6)?, β = 88.18(1)?. The structure was determined by MULTAN-80. First, the bromine atom was located on the .E-map and the remaining 26 non-hydrogen atoms were determined by weighted Fourier synthesis. The atomic parameters were refined isotropically and anisotropically for two cycles respectively, then all the hydrogen atoms were located in the subsequent difference synthesis. Full matix least square refinement was made with the non-hydrogen atoms anisotropically and hydrogen atoms isotropically, to a final discrepency factor of R = 0.0776.
This compound (C22H18O2ClBr) is monoclinic, with space group P21/n and α = 19.502(10)?, b = 9.118(5)?, c = 11.233(6)?, β = 88.18(1)?. The structure was determined by MULTAN-80. First, the bromine atom was located on the .E-map and the remaining 26 non-hydrogen atoms were determined by weighted Fourier synthesis. The atomic parameters were refined isotropically and anisotropically for two cycles respectively, then all the hydrogen atoms were located in the subsequent difference synthesis. Full matix least square refinement was made with the non-hydrogen atoms anisotropically and hydrogen atoms isotropically, to a final discrepency factor of R = 0.0776.
The YLID-IV (C22H18O3PCl3) crystal belongs to the monoclinic system with space group P21/n and unit cell parameter α = 13.518(6)?, b = 14.923(7)?, c = 11.473(5)?, β = 99.81(2), z = 4. The intensity data were collected on the Philips PW-1100 diffrac-tometer. The structure was determined by direct method (MULTAN-78) and refined by full-matrix least-squares method to a final R value of 0.074 for 2592 reflexions. The hydrogen atom locations were determined by difference Fourier synthesis.
The YLID-IV (C22H18O3PCl3) crystal belongs to the monoclinic system with space group P21/n and unit cell parameter α = 13.518(6)?, b = 14.923(7)?, c = 11.473(5)?, β = 99.81(2), z = 4. The intensity data were collected on the Philips PW-1100 diffrac-tometer. The structure was determined by direct method (MULTAN-78) and refined by full-matrix least-squares method to a final R value of 0.074 for 2592 reflexions. The hydrogen atom locations were determined by difference Fourier synthesis.
The Armillarine (C24H30O6) crystal belongs to the orthorhomcic system with space group P21 21 21 and unit cell parameter α= 18.784(9)?, b = 14.002(7)?, c = 8.598(5)?, z= 4. The calculated density Dc= 1.216 g· cm-3.The intensity data were collected on the Philips PW-1100 diffractometer. The structure was determined by MULTAN-80 with the statistically weighted tangent formula after MULTAN-78 had been proved unsuccessful. The structure has been refined by full-matrix least-squares method to a final R value of 0.076 for 1624 reflexions. The hydrogen atom locations were determined by difference Fourier synthesis.
The Armillarine (C24H30O6) crystal belongs to the orthorhomcic system with space group P21 21 21 and unit cell parameter α= 18.784(9)?, b = 14.002(7)?, c = 8.598(5)?, z= 4. The calculated density Dc= 1.216 g· cm-3.The intensity data were collected on the Philips PW-1100 diffractometer. The structure was determined by MULTAN-80 with the statistically weighted tangent formula after MULTAN-78 had been proved unsuccessful. The structure has been refined by full-matrix least-squares method to a final R value of 0.076 for 1624 reflexions. The hydrogen atom locations were determined by difference Fourier synthesis.
In this paper, the characteristic impedances of coupled square bar transmission line between parallel plates is solved by method of ref. [3], the formulae of calculating characteristic impedances of this coupled transmission line is obtained. The accuracy is confirmed by comparing the numeral values and theortical analysis. The exact values of characteristic impedances of this coupled transmission line are given in the paper for references.
In this paper, the characteristic impedances of coupled square bar transmission line between parallel plates is solved by method of ref. [3], the formulae of calculating characteristic impedances of this coupled transmission line is obtained. The accuracy is confirmed by comparing the numeral values and theortical analysis. The exact values of characteristic impedances of this coupled transmission line are given in the paper for references.
In this paper, we analyse the pair correlation effects of a multicomponent plasma system in which the electron-electron, ion-ion and ion-electron correlations are considered. The equation of state for a dense bi-maxwellian plasmas are derived.
In this paper, we analyse the pair correlation effects of a multicomponent plasma system in which the electron-electron, ion-ion and ion-electron correlations are considered. The equation of state for a dense bi-maxwellian plasmas are derived.
In this note, we report five new UV laser transitions of chlorine: 394.3 nm, 367.0 nm, 365.7 nm, 307.7 nm and 306.3 nm, among which the 394:3 nm one is the strongest. It is observed that the gain of 263.3 nm transition is higher than 30% per. metre and the transition energy levels of this line are also identified.
In this note, we report five new UV laser transitions of chlorine: 394.3 nm, 367.0 nm, 365.7 nm, 307.7 nm and 306.3 nm, among which the 394:3 nm one is the strongest. It is observed that the gain of 263.3 nm transition is higher than 30% per. metre and the transition energy levels of this line are also identified.