A 44 GHz monolithic semiconductor dipole antenna

Monolithic semiconductor antennas integrated with a diode detector have been fabricated using silicon-on-sapphire technology. The performance of these antennas is analyzed on the basis of earlier theoretical work on imperfectly conducting/resistive cylindrical dipoles. The measured radiation patterns of semiconductor antennas are compared with those of the corresponding printed metal dipoles.     

Yukawa's Heavy Quantum and the Mesotron (1935-1937)

The unified “standard model’ of strong and weak nuclear forces of the mid-1930s was based on the emission and/or absorption of an electron and a neutrino, the so-called Fermi field, by the proton and the neutron. However, theorists could never explain simultaneously the required nuclear properties, such as saturation, strength, range, and charge independence of nuclear forces, while also accounting for β-decay. Yukawa proposed to exchange, instead of the Fermi field, the massive charged quanta of a new field which he invented, the U-field. His theory, however, languished for about two years. In this paper we describe this central episode in the history of elementary particle physics from Yukawa's proposal, published in 1935, to the year 1937 when particles resembling the quanta of the U-field were detected in the cosmic rays.     

Attentional processes in time perception: Effects of mental workload and event structure.

The role of attention in timing was evaluated in 2 experiments. In Experiment 1, participants reproduced the durations of melodies with either a coherent or an incoherent structure. Participants were tested under control (timing only) and detection (timing plus target detection) workload conditions. Reproductions were shorter and more inaccurate under detection conditions, and incoherent event structure extended the effect to a wider range of durations. In Experiment 2, participants reproduced the durations of auditory prose passages that represented 3 levels of mental workload and 3 levels of event structure. Both increases in workload and the degradation of structure led to inaccurate reproductions. The results point to the central role of attention in temporal experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When Gulliver travels: Social context, psychological closeness, and self-appraisals.

Four studies examined how the characteristics of others affect people's self-appraisals. Ss viewed photographs of physically attractive or unattractive targets, then rated their own attractiveness. Study 1 found evidence for a contrast effect: Ss' self-appraisals were more favorable after viewing an unattractive same-sex target than after viewing an attractive same-sex target. Study 2 manipulated psychological closeness by varying the degree to which the S and the target shared similar attitudes and values. Although contrast effects occurred when the S and the target were dissimilar, the reverse tended to be true when the S and the target were related by virtue of their perceived similarity. Two additional studies extended these results, using a different operational definition of psychological closeness. Findings indicate that psychological closeness determines how other people's characteristics affect the self-concept. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct analysis of sugar alcohol borate complexes in plant extracts by matrix-assisted laser desorption/ionization fourier transform mass spectrometry

Matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI/FTMS), operating in the negative ion mode, is used to directly observe sugar alcohol borate complexes in a number of plant fractions. The method involves virtually no sample workup and, in the case of celery phloem sap, requires only 40 nL of sap to observe the borate complex. The isolation and characterization of such soluble borate complexes is important in understanding the distribution of boron in plants. The results show that the complexes are composed of two mannitol or sorbitol ligands (L) complexed to a single borate center (B). In some cases, the boron is complexed to non-alditol monosaccharides. Sustained off-resonance collision irradiation dissociation of the BL2- complex, where L is a mannitol, gives fragments that confirm the proposed structure. Complexes of larger oligosaccharides have also been successfully observed using MALDI/FTMS. Semiempirical molecular orbital calculations (AM1) of the mannitol BL2- complex show that the most favorable configuration is with carbons 3 and 4 of both mannitol residues complexed to the borate. This allows maximum interaction of the remaining hydroxyls with the borate center.