Smart microscope: an adaptive optics learning system for aberration correction in multiphoton confocal microscopy

Off-axis aberrations in a beam-scanning multiphoton confocal microscope are corrected with a deformable mirror. The optimal mirror shape for each pixel is determined by a genetic learning algorithm, in which the second-harmonic or two-photon fluorescence signal from a reference sample is maximized. The speed of the convergence is improved by use of a Zernike polynomial basis for the deformable mirror shape. This adaptive optical correction scheme is implemented in an all-reflective system by use of extremely short (10-fs) optical pulses, and it is shown that the scanning area of an f:1 off-axis parabola can be increased by nine times with this technique.     

Polarography of some 2,1,3-benzothiadiazoles,benzofurazans, 2,1,3-benzoselenadiazoles,and 3,4-disubstituted and fused 1,2,5-thiadiazoles

The redox behavior has been determined in acetonitrile solutions at a mercury and platinum electrode for 2,1,3-benzo(group VI)diazoles, and 3,4-disubstituted and fused 1,2,5-thiadiazoles. The derivatives studied contained alkyl, phenyl, bromo, chloro, cyano, nitro, methylsulfonyl, and trifluoromethylsulfonyl groups. All ring systems and their derivatives are reversibly reduced initially in a one-electron step, to their respective radical anion, but the nitro and bromo derivatives are reduced preferentially at the substituent group. The potential at which the production of the radical anion occurred became more anodic as the electron withdrawing ability of the substituent and the number of substituents increased.     

Infrared spectra of FHF− in alkali halides

The bifluoride ion, FHF^?, has been substitutionally isolated within single crystal samples of several different alkali halides. Infrared spectra of these crystals have been studied for sample temperatures down to 8K when half-bandwidths of less than 1 cm^?1 have been observed. (Note that at room temperature ν₃ is observed to have a half-bandwidth of about 40 cm^?1). The frequency shifts and half-bandwidth changes caused by cooling are considered together with the frequency shifts caused by pressures up to 10 k bar.The low temperature spectra clearly indicate that FHF^? is a linear symmetrical ion when substitutionally isolated within alkali halides of either the NaCl or CsCl structure.     

The reactionpd → ppn and the narrow dibaryon resonances

The effective mass spectra of two nucleons from the reactionpd →ppn were studied at four incident proton energies in the range 800–1000 MeV, one of nucleons being backward emitted. After selecting the events either with large nucleon momenta or with large opening angles between the nucleons several narrow peaks are observed in the effective mass spectra (M=1.95, 2.03, 2.08 and 2.14 GeV/c²) which can be considered as probable dibaryon resonances.     

Molecular reorientational dynamics of d-camphor systems under high pressure

The molecular dynamics of the plastic phase of d-camphor and d-camphor in n-hexane were probed using Raman spectroscopy. The orientational correlation functions of the various systems were found to decay at equal rates in the short time. In the time domain 0 to 1.5 ps the molecular reorientation of d-camphor molecules in n-hexane solution seems to be unaffected by pressures up to 5 kbar.     

Role of barrier penetration in complete fusion of heavy ions

The relevance of tunneling in determining the cross section for complete fusion is explored. The classical model with frictional forces is used for the determination of the trajectory of two heavy ions up to the classical turning point. The penetrability of the barrier is calculated quantum mechanically. It is shown that the so calculated transmission coefficient differ from the sharp cut-off approximation, but yield cross section for complete fusion which are not significantly different from the cross section neglecting quantum mechanical effects.     

X-ray photoelectron spectroscopy study of the chemisorption of water on uranium and thorium and oxygen on uranium

The initial stages of water and oxygen adsorption on clean uranium and thorium and oxygen adsorption on uranium has been studied by X-ray photoelectron spectroscopy. These measurements are made in the vicinity of 120 K; in some cases the effect of temperature was followed up to 500 K. Three oxygen (1s) photoelectron peaks are observed for water adsorbed on uranium and thorium. All three peaks have binding energies different from the adsorption of oxygen. The uranium and thorium ($\text{4}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$) lines also have different binding energies for water adsorption than for oxygen adsorption. Oxygen and an OH complex combine with uranium and thorium in a complex way, precluding the initial formation of simple oxides and confirming the importance of OH in the interaction of water with uranium and thorium.     

The state of water in Y-type zeolites

Conclusions By titration with Fischer's solution and thermodesorption the authors show that the firmly combined water conteat of Y-type zeolites depends on the nature of the ion-exchange cation and the heat-treatment conditions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 276–279, February, 1976.     

Determination of water in some aqua-and heteropolytungstates

Conclusions Both the data of the present study and those obtained earlier make it possible to assume that in certain cases the Fischer reagent can be used to ascertain the structure of inorganic hydrated solids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1120–1121, May, 1971.