Browsing Articles  Science and Technology by Issue Date
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Geodesic round trips by parallel transport in quantum gravity
(AMERICAN PHYSICAL SOC, 1993)We study the vacuum correlations of a gravitational field in any dimension N > 2 using the perturbative expansion to order G. It is known that the usual Green's functions are meaningless in quantum gravity; moreover, we ... 
Ultrafast thermalization of photoexcited carriers in polar semiconductors
(AMERICAN PHYSICAL SOC, 1993)We present a combined experimental and theoretical study of ultrafast thermalization of highenergy carriers photogenerated by femtosecond laser excitation in GaAs and InP. Luminescence upconversion is used to monitor the ... 
A Comparison of Monte Carlo and Cellular Automata Approaches for Semiconductor Device Simulation
(IEEEINST ELECTRICAL ELECTRONICS ENGINEERS INC, 1993)We present a detailed comparison of Monte Carlo and cellular automata approaches as applied to the study of nonequilibrium transport and semiconductor device simulation. We show that the novel cellular automata (CA) technique ... 
The radial gauge propagators in quantum gravity
(ACADEMIC PRESS INC JNLCOMP SUBSCRIPTIONS, 1993)We give a general procedure for extracting the propagators in gauge theories in the presence of a sharp gauge fixing and we apply it to derive the propagators in quantum gravity in the radial gauge, both in the first and ... 
Fenotipi di pregio di noce per l’arboricoltura da legno nelle Prealpi Tevigiane
(1994)Vengono riportati i risultati di un'indagine svolta nelle Prealpi trevigiane con lo scopo di individuare "fenotipi superiori" di noce da utilizzare come capostipiti nei programmi di miglioramento genetico per l'arboricoltura ... 
Das Galio harcyniciCultoPiceetum als FichtenForstgesellschaft bodensaurer Waldstandorte im deutschen Mittelgebirgsraum
(1994)Forstgesellschaften mit vom Menschen künstlich geförderten Baumarten (v.a. Fichte und Kiefer) haben seit der ersten Hälfte des letzten Jahrhunderts einen hohen Anteil an der forstwirtschaftlich genutzten Fläche im deutschen ... 
Effect of soil humic substances on surface redox activity of oat roots
(1995)The effect of a low molecular weight (<5kDa, LMW) and a high molecular weight (>5kDa, HMW) humic fractions on surface redox activities of oat roots was studied. Oxidation of the electron donor NADH and reduction of the ... 
Plasma Membrane H+ATPase in Maize Roots Induced for NO3 Uptake
(1995)Plasma membrane H+ATPase was studied in maize (Zea mays L.) roots induced for NO3 uptake. Membrane vesicles were isolated by means of Suc density gradient from roots exposed for 24 h either to 1.5 mM NO3 or 1.5 mM SO4. ... 
Pedogenic evolution and 137Cs contents in soils of the Eastern Alps (FriuliVenezia Giulia, Italy)
(1995)Two lithosequences were examined, starting from siliceous and calcareous parent material, respectively. The morphological and chemical soil properties allowed to evidentiate different evolutionary trends. Radioactivity ... 
Plasma Membrane H+ATPase in Maize Roots Induced for NO3 Uptake
(1995)Plasma membrane H+ATPase was studied in maize (Zea mays L.) roots induced for NO3 uptake. Membrane vesicles were isolated by means of Suc density gradient from roots exposed for 24 h either to 1.5 mM NO3 or 1.5 mM SO4. ... 
Homoclinic solutions of quasiperiodic Lagrangian systems
(Khayyam Publishing, 1995)We consider quasiperiodic positive definite Lagrangian systems and establish the existence of one or more solutions homoclinic (namely asymptotic as $t o \pm \infty$) to a quasiperiodic solution. These results are obtained ... 
Castration technique for Llamas
(SCHLUTERSCHE VERLAG DRUCKEREI, 1995)Llamas and alpakas have gained and maintained popularity in the United States and Europe. Castration is the most common surgical procedure performed on llamas. It decreases the number of undesirable genetic characteristics, ... 
An efficient multigrid poisson solver for device simulations
(1996)The aim of this paper is to show that the multigrid approach can provide an efficient twodimensional Poisson solver used in the analysis of realistic semiconductor devices based on particle simulators. Our robust implementation ... 
General properties of the decay amplitudes for massless particles
(ELSEVIER SCIENCE BV, 1996)We derive the kinematical constraints which characterize the decay of any massless particle in flat spacetime. We show that in perturbation theory the decay probabilities of photons and YangMills bosons vanish to all ... 
Selfconsistent tightbinding calculations of electronic and optical properties of semiconductor nanostructures
(PERGAMONELSEVIER SCIENCE LTD, 1996)Optical properties and electronic states of semiconductor nanostructures are calculated by using tightbinding models which account for valence band mixing, strain and external applied potentials in a selfconsistent ... 
Experimental and Monte Carlo analysis of impactionization in AlGaAs/GaAs HBT's
(IEEEINST ELECTRICAL ELECTRONICS ENGINEERS INC, 1996)We present a detailed experimental and theoretical investigation of hot electron effects occurring in AlGaAs/GaAs Heterojunction Bipolar Transistors (HBT's) operating at low current densities, Electrons heated by the strong ...