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  • 1
    ISSN: 1435-1463
    Keywords: Pinealocytes ; mole ; sexual cycle ; ultrastructure ; paracrystalline structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resume L'évolution quantitative de quelques paramètres ultrastructuraux (structures paracristallines, appareils de Golgi, grains de sécrétion) des pinéalocytes de la taupe, a été suivie pendant les différentes phases du cycle sexuel. Cette étude a permis de montrer une augmentation du nombre des structures paracristallines et des appareils de Golgi pendant la phase de pleine activité sexuelle chez les mâles et pendant l'œstrus, la gestation et la lactation chez les femelles. De plus, l'apparition d'un phénomène de vacuolisation des pinéalocytes a été observée pendant le proestrus. Ces résultats semblent démontrer d'étroites relations entre l'activité endocrine de l'axe adénohypophyse-gonades et l'accroissement des synthèses des pinéalocytes. Aucune évolution du nombre de grains de sécrétion n'a été observée pendant les différentes phases du cycle sexuel.
    Notes: Summary Changes of some ultrastructural parameters (paracrystalline structures, Golgi apparatus, secretory granules) in mole pinealocytes were quantitatively studied during the various phases of the sexual cycle. An increase in quantity of paracrystalline structures and of the Golgi apparatuses was demonstrated during the period of high sexual activity in male pinealocytes and during oestrus, gestation and lactation in female pinealocytes. Moreover, the appearance of vacuoles in female pinealocytes was observed during pro-oestrus. These results seem to demonstrate close relationship between the endocrine activity of the hypophyseo-gonadal axis and the synthesis of some compounds by the pinealocytes. No increase in the quantity of secretory granules was observed during the various phases of the sexual cycle studied.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 37 (1985), S. 171-179 
    ISSN: 1432-0649
    Keywords: 42.55D ; 42.60B ; 58.80
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The performance of a compact uv photo-preionized TE laser is studied in the pressure range 1–5 bar. As the pressure is increased, the laser pulse shape is little altered, but both the peak power and the total output pulse energy increase significantly with pressure, even for constant input electrical energy. For various gas mixtures and excitation source capacitors the measurements suggest approximate output energy scaling with the product of the source charge per unit electrode area [C.m−2] and the molecular partial pressure [CO2+N2+CO]. This is explained in terms of the pressure-dependent discharge impedance. An input-energy-related discharge instability limits the optimum laser pressure to 1.5–2.5 bar, and we show that, at constant input energy, the instability boundary depends on the molecular partial pressure alone. The pre-ionization photo-electron yield varies negligibly with pressure, but the discharge tolerance to added oxygen decreases asp −3 top −4, dependent on gas mixture. Nevertheless sealed operation for 〉105 shots has been obtained with a 5% CO2∶5% CO∶3% N2∶2% H2∶85% He gas mixture at a total pressure of 5 bar.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 33 (1984), S. 99-101 
    ISSN: 1432-0649
    Keywords: 42.60B ; 42.55D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A compact hybrid TEA CO2 laser has been developed which, when operated with the low pressure section well below oscillation threshold, demonstrates that little cw gain is necessary to ensure single longitudinal mode (SLM) output pulses with peak power, energy and pulse shape approaching those of normal multi-mode operation. This has allowed reliable SLM operation to be obtained with a very short, wide bore rf-excited low-pressure section, making feasible simple single-mode, large-aperture TEA lasers with high peak powers and energies.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 37 (1985), S. 219-221 
    ISSN: 1432-0649
    Keywords: 42.55D ; 33.80E ; 52.80 ; 42.60B
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A short pulse (100 ns) high-energy x-ray source has been used to preionize a transversely excited carbon dioxide gas discharge laser of 600 cm3 active volume. The maximum output power of 60 MW in a 50 ns FWHM pulse was achieved from a CO2−N2−He−CO−Xe static gas mixture at 600 Torr pressure. The energy conversion efficiency was 6%.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 16 (1978), S. 111-118 
    ISSN: 1432-0630
    Keywords: 42.55D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Negative ions are computed to be formed on a time scale and in quantities such that they may be a cause of plasma instability observed in low pressure electrical discharge convection CO2 lasers. In a typical CO2−N2−He−H2O laser mixture the principal ions are CO 3 − , CO 4 − and H− with the total negative ion densityn − given by 0.1n e 〈n −〈n e , wheren e is the electron density: but if the gases are re-cycled or if there is an air leak NO 2 − and NO 3 − are formed in significant amounts andn − can become greater thann e in a time considerably less than the gas dwell time in the electrical excitation discharge. CO is effective in reducingn − in a system without re-cycling, but is ineffective in a re-cycled system with the oxides of nitrogen present.
    Type of Medium: Electronic Resource
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