We demonstrate a passively mode-locked thin-disk Yb:YAG laser that generates solitonlike pulses with durations that are continuously tunable in a very wide range from 3.3 to 89 ps or from 0.83 to 1.57 ps. The average powers are typically ~12 W . Previously [Opt. Lett. 25, 859 (2000)], only pulse durations in a narrow range near 0.7 ps could be obtained from such lasers because of the effect of ...

We have studied the influence of structural defects on the spatial variation of radiative and nonradiative recombination in an InGaAs/AlGaAs/GaAs resonant cavity enhanced npn heterojunction phototransistor ~HPT! structure using cathodoluminescence ~CL! and electron beam-induced current ~EBIC! imaging. Absorber layers of InGaAs/GaAs multiple quantum wells ~MQWs! are used to provide the photosens...

Paper folding tests are used to measure spatial abilities in humans. Artificial agents with strong intelligence must have reasoning mechanisms to solve spatial problems cognitively. In this paper, a qualitative descriptor for paper folding (QD-PF) is presented. QD-PF defines the folding actions which appear in the problem and the areas in the paper where a hole can be punched. Reasoning tables ...

Temperature cycling optical hole-burning experiments on cresyl violet in ethanol glass are reported. At 1.3 K a hole is burned and measured. The temperature if then raised to 2.1 IQ the hole is measured. The temperature is returned to I, 3 K, and the hole is again measured. The hole is observed to be narrow at 1.3 K, broader at 2.1 K, and then narrow again when the temperature is returned to 1....

The universality of Martinez’s conjecture, which states that quasilocal energy of a black hole at the outer horizon reduces to twice its irreducible mass, or equivalently, to √ A/4π (A is the area of the black hole), is investigated by calculating Brown-York quasilocal energies for stationary black holes in heterotic string theory, such as for the stationary Kaluza-Klein black hole, the rotatin...

The universality of Martinez’s conjecture, which states that the quasilocal energy of a black hole at the outer horizon reduces to twice its irreducible mass, or equivalently, to √ A/4π (A is the area of the black hole), is investigated by calculating Brown-York quasilocal energies for stationary black holes in heterotic string theory, e. g., for the stationary Kaluza-Klein black hole, the rota...

AGNs with narrow Balmer lines show various extreme properties. In particular, rapid X-ray variability, steep X-ray spectra, peculiar optical and UV line ratios, and possibly peculiar line profiles. Since all these phenomena occur together they are likely to be related to one specific underlying physical parameter. I review recent evidence, based on HST imaging of low z quasars, which suggests t...

We present the results of deep spectroscopy for the central region of the cluster lens SDSS J1004+4112 with the Subaru telescope. A secure detection of an emission line of the faint blue stellar object (component E) near the center of the brightest cluster galaxy (G1) confirms that it is the central fifth image of the lensed quasar system. In addition, we measure the stellar velocity dispersion...

A time-variability study of the neutral iron line flux at 6.40 keV in the Sgr B2 region from data of Suzaku and Chandra is presented. The highly ionized iron line at 6.68 keV is due to Galactic Center Diffuse X-rays (GCDX), and is thus time invariable. By comparing the 6.68 keV and 6.40 keV line fluxes, we found that the 6.40 keV flux from the Sgr B2 complex region is time variable; particularl...

We discuss the evolution of black hole transients on the basis of a few systems that were intensively observed with the Rossi X-ray Timing Explorer. We focus on the global evolution and the observed state transitions. Rather than giving a numerical recipe for classifying observations, we try to identify times during outbursts at which clear changes occur in the X-ray variability, X-ray spectral...