米其林低滚动阻力绿色环保轮胎

世界著名轮胎制造商米其林呼吁全欧洲的汽车都改用绿色环保轮胎。米其林称．如果欧洲所有的汽车都装备低滚动阻力的绿色环保轮胎，每年将节省45亿升柴油和15亿升汽油．同时每年将减少二氧化碳排放1500万吨．相当于6亿棵树1年吸收的二氧化碳的总和。     

Wigner distribution moments in fractional Fourier transform systems

It is shown how all global Wigner distribution moments of arbitrary order in the output plane of a (generally anamorphic) two-dimensional fractional Fourier transform system can be expressed in terms of the moments in the input plane. Since Wigner distribution moments are identical to derivatives of the ambiguity function at the origin, a similar relation holds for these derivatives. The general input-output relationship is then broken down into a number of rotation-type input-output relationships between certain combinations of moments. It is shown how the Wigner distribution moments (or ambiguity function derivatives) can be measured as intensity moments in the output planes of a set of appropriate fractional Fourier transform systems and thus be derived from the corresponding fractional power spectra. The minimum number of (anamorphic) fractional power spectra that are needed for the determination of these moments is derived. As an important by-product we get a number of moment combinations that are invariant under (anamorphic) fractional Fourier transformation.     

Paramagnetism and Electrical Conductivity Centre Relation in Semiconductor Oligoresorcinol

The electrical properties of oligoresorcinols with various concentrations of paramagnetic centres (N_s) in constant and variable electric fields have been investigated. It has been established that the electrical conductivity and the tangent of the dielectric loss angle are increased with the growth of N_s in the composition of the oligoresorcinol. With increase of frequency the electrical conductivity of oligoresorcinol increases according to the usual law. It has been shown that the electrical conductivity and concentration of paramagnetic centres of oligoresorcinol are interrelated and charge transfer in a variable field predominates at the expense of jumps of charge bearers between localized states with energy near the Fermi level. The densities of the states near the Fermi level for resorcinol examples have been calculated. The results show that, in this case, paramagnetic centres of the aroxyl type determine the density of the localized states near the Fermi level. © 1997 SCI.     

Stability analysis of the FitzHugh-Nagumo differential equations driven by impulses: applied to the electrical firing of magnocellular neurons

A stability analysis is carried out for a mathematical model which describes the electrical firing of a single vasopressin neuron. The model used in a FitzHugh-Nagumo-type system which is driven by impulses. The analysis is based on recent developments in the stability theory of impulsive differential equations. Conditions are derived under which the system of differential equations is stable at two of its equilibrium points. Biologically this bistability represents the cell alternating between periods of electrical activity and silence. The conditions for stability are specified in terms of the amplitude and frequency of the impulses perturbing the system. Both stochastic and deterministic impulses are considered.     

Antibodies to beta2-glycoprotein I in systemic lupus erythematosus: new laboratory marker of antiphospholipid syndrome

Antibodies to beta 2-glycoprotein in the serum of patients with antiphospholipid syndrome (APS) were found by many investigators, but their results appeared contraversional. We studied clinical significance of antibodies to beta 2-glycoprotein I (anti-beta 2-GPI) in patients with SLE. 69 patients with verified SLE were examined for lupus anticoagulant (LA), antibodies to cardiolipin (aCL) and anti-beta 2-GPI. 44(65%), 46(67%), 49(71%), 19(28%), 16(23%) patients were positive for LA, IgG-aCL, IgM-aCL, IgG-anti-beta 2-GPI and IgM-anti-beta 2-GPI, respectively. Hyperproduction of IgG-anti-beta 2-GPI correlated with APS development as a whole, its separate clinical symptoms (venous and arterial thromboembolism, obstetric pathology and thrombocytopenia) and some comcomitant clinical signs (trophic crural ulcer, hemolytic anemia, valvular heart disorders). Moreover, an increase in concentration of IgM-anti-beta 2-GPI was associated with habitual abortion. Both isotypes of anti-beta 2-GPI occurred more frequently in the sera positive by LA and aCL. It is interesting that we discovered IgG-anti-beta 2-GPI more often in early than late postthrombolytic period. Thus, anti-2b2-GPI is a new serological marker of APS. Its detection is clinically important for upgrading diagnosis of APS.     

Finite mode analysis through harmonic waveguides

The mode analysis of signals in a multimodal shallow harmonic waveguide whose eigenfrequencies are equally spaced and finite can be performed by an optoelectronic device, of which the optical part uses the guide to sample the wave field at a number of sensors along its axis and the electronic part computes their fast Fourier transform. We illustrate this process with the Kravchuk transform.     

Computer analysis of microstructures for evaluation of the effect of beta-irradiation on the skin]

Hormonal levels were tested in postweanling rats, because these had not been well established despite much testing on adult animals. Holtzman rats, 25-26 days old, that had been handled daily were decapitated at various times of the day. Radioimmunoassays were used to measure serum levels of luteinizing hormone, follicle stimulating hormone (FSH), testosterone, androstenedione, progesterone, and 20alpha dehydroprogesterone. Only FSH, testosterone, and androstenedione showed a significant variation with time. The maximal values occurred late in the dark and early in the light period.