Search

application/pdf, The relation between the apparent stability of adiabatic circulation and thermal equilibrium is examined. The condition of both constant temperature and constant sum of chemical potential and gravitational potential implicitly includes the gravitational equilibrium. While no entropy change occurs with the transfer of a small portion of gas in adiabatic equilibrium, the transfer of an independent particle certainly causes the increase of entropy. The quantity of energy supply is calculated which is required to cause an adiabatic circulation under the boundary condition of initial isothe1mal equilibrium. Also the thermodynamic process is considered to cause reversibly an isothermal cil・culation under the boundary condition of initial adiabatic equilibrium. When the adiabatic equilibrium is attained it corresponds to the extremum of total energy. Stationary adiabatic circulation is kept with no additional energy supply. It seems to correspond to a quasi-equilibrium in which the apparent stability of adiabatic circulation is kept.

application/pdf, The relation of the excitation on the Fermi surface in quantum theory to the excitation of many individual electrons in semi-classical picture is clarified by the invariance of diagonal sum by unitary transformation. The proof is given that the effect of small perturbations on many electrons is equivalent to strong modification of a few electrons on the Fermi surface, so long as the perturbing operator is unitary. The problem of cooling process in thermoelectric effect under a magnetic field, which is difficult to treat in conventional method, is clarified by this correspondence.

application/pdf, The response to an impulse electric field is analyzed in order to investigate the heat flow in an electric field and a magnetic field perpendicular to it. The relations of the Fermi statistics with the excited state by an impulse electric field and with the relaxation process are investigated. It is clarified that both are expressed by the strongly modified wave functions at the Fermi level together by the Fermi sphere under it. This state nearly corresponds to the semi-classical theory where the individual electron gains or loses momentum and energy. The heat flow is caused by the energy moment of the strongly modified wave function. It is again confirmed that if the relaxation is forbidden for cooling process the relaxation for heating process on the other edge is also forbidden owing to Fermi statistics.

application/pdf, The heat flow in an electric field and a magnetic field perpendicular to it is discussed. The response to an impulse electric field is analyzed instead of a static electric field. This method clarifies some quantum mechanical aspects of the problem, which is difficult to see in a static electric field. In most cases, the semi-classical theory is valid. This result intensifies the importance of Landau diamagnetism expected to lead to a significant thermoelectric effect. In some cases of low temperature such that the relevant phonons are not excited, the relaxation is forbidden not only for excited states having lower energy than in equilibrium but also for the whole electron system owing to Fermi statistics.

application/pdf, The Landau diamagnetism in a transient field strength is studied. The orbit radius of the ground state is smaller than the sample size, while those near the Fermi energy are larger. The thermodynamic potential Ω (H,μ) is investigated. The shift in Ω (H,μ) due to the boundary effect is far larger than the Landau energy,however,nearly the same term already exists at H=0. The E-o relations are examined for the boundary condition that the phase at the boundary is r/2. The average of the shift in Ω (H,μ) for 0 and 1/2 is evaluated. A singular diamagnetic moment is possible to appear in the transient region.

application/pdf, In order to obtain an information of Z(β) near β=0, substitution of (x-X)2 by some suitable function is examined. The result by this method agrees with an exact calculation by a mirror image method. However, it has a possibility of general applicability as different from a mirror image. Some difficult problems become soluble, provided the suitable function has only a few non-diagonal matrix elements.

application/pdf, An exact proof is given that such a steady term in surface Landau diamagnetism =f(μ)H1 -γ (f(μ);of definite sign, γ>0) for H→0, is non-existent in any region a vanishes.

application/pdf, The unified theory of Landau diamagnetism for both in thin film and in large system is developped on the basis of the density matrix. The density matrix for thin film is solved by Laplace transform. It is clarified why the steady terms of both agree. This method makes possible to calculate the 2-dimensional susceptibility, which leads to the result of great interest that there appears an oscillating term of an enormous magnitude.

application/pdf, The density matrix of free electrons confined in a large box is calculated by perturbation. The relation beteween the second order term and the average value of magnetization is discussed. The uniform convergence of Z(β) in the limited region near β=0 requires some restriction on the shape of くM(μ,H)>. Exact derivation gives the conclusion that a divergent term in with H→0 is non-existent.

application/pdf, The method for general treatment of Landau diamagnetism in thin film is discussed. Exact value of the moment is given by a simple method for αH estimation as well as by the relation between WKB and exact αH2 term in the wave equation. The relation between the current distribution and the sum of moments is clarified. The sum along the equal energy circle with equal z-direction momentum is shown nearly to vanish. The prospect for the case of more general potential is obtained.

application/pdf, The whole of Lorentz force together with Maxwell equation are not required for the first principle in electromagnetism. It is shown that total energy conservation law together with Maxwell equation or equivalently electrostatic force together with Maxwell equation is sufficient for the first principle. Electromagnetic force is derived from them without depending on the assumption of special relativity.

application/pdf, The exact treatment of Landau diamagnetism by using the r-α (energy versus center of orbit) tragectories, which was developed by the author for the case of infinite work function, is generalized to an arbitrary shape of potential. The calculation for the case of finite height square potential is carried out. Exact result is given that no enormous divergence appears.

application/pdf, 電気電子工学

In vivo 1H-magnetic resonance imaging (MRI) enabled us to study the distribution of water in living tissues and to document changes in human skeletal muscles during physical exercise. The purpose of the present study was to determine the total muscle water changes after exercise using water in 1H-MR spectroscopy and to compare these changes to the signal intensity change on T2*-weighted images and/or to the T2 value change. Seven young male volunteers were positioned in a 1.5 T Philips MR imaging system. They were then asked to dorsiflex their ankle joint against a 2 kg weight once every 2 seconds for 2 minutes. The peak height of water declined according to the clearance curve after exercise in all seven cases with the 1H-MRS similar to the signal intensity. The increasing rate at peak height of total muscle water exceeded both the signal intensity and the T2 value because the water peak height on the 1H-MRS included the extracellular water. In addition, we measured the changes in signal intensity in both calf muscles after walking race exercise. The time intensity curves were used to draw a clearance curve for each muscle group after exercise. It was possible to discern which muscle was used most from the T2*-weighted image that was obtained once after exercise.

application/pdf, 電気電子工学

application/pdf, 電気電子工学

application/pdf, 電気電子工学

A total of 649 bone scintigram reports were stored using a voice pattern recognition system in a general-purpose medium-sized computer ACOS-650, and bone scintigraphy carried out in this institute was examined by analysing these data. The results showed that the introduction of the system made it possible to analyse all the data quickly, whereas previously the amount of information that could be analysed was restricted because of the complexity of the data. The results also showed that the system would be useful for understanding the examinations carried out in the whole hospital as well as for analysing metastatic tumours and the numbers of patients receiving examinations. Furthermore, it would be helpful in the logical analysis of reports prepared by doctors.

application/pdf, 電気電子工学

application/pdf, 電気電子工学

Summary: Although 3D-CT angiography provides valuable anatomic information regarding lesion and their surrounding vessels and bony structures, it cannot demonstrate lesions, arteries, and veins, separately. The separate demonstration of arterial-phase 3D-CT angiography (3D-CT arteriography) and venous-phase 3D-CT angiography (3D-CT venography) will facilitate the understanding of the vascular anatomy within lesions, thus, allowing improvement of diagnostic accuracy and potentially a safer surgical approach. We describe 3D-CT arteriography and 3D-CT venography by using a multidetector row helical CT.