Towards an Improved Test of the Standard Model's Most Precise Prediction

The electron and positron magnetic moments are the most precise prediction of the standard model of particle physics. The most accurate measurement of a property of an elementary particle has been made to test this result. A new experimental method is now being employed in an attempt to improve the measurement accuracy by an order of magnitude. Positrons from a "student source" now suffice for the experiment. Progress toward a new measurement is summarized

Lick Slit Spectra of Thirty-Eight Objective Prism QSO Candidates and Low Metallicity Halo Stars

We present Lick Observatory slit spectra of 38 objects which were claimed to have pronounced ultraviolet excess and emission lines by Zhan \& Chen. Most of our spectra have FWHM spectral resolutions of about 4~\AA , and relatively high S/N of about 10 -- 50, although some have FWHM $\simeq 15$~\AA ~or lower S/N. We find eleven QSOs, four galaxies at $z \simeq 0.1$, twenty-two stars and one unidentified object with a low S/N spectrum. Six of the QSOs show absorption systems, including Q0000+027A with a relatively strong associated C~IV absorption system, and Q0008+008 (V$\simeq 18.9$) with a damped Ly$\alpha$ system with an H~I column density of $10^{21}$ cm$^{-2}$. The stars include a wide variety of spectral types. There is one new DA4 white dwarf at 170~pc, one sdB at 14~kpc, and three M stars. The rest are of types F, G and K. We have measured the equivalent widths of the Ca~II~K line, the G-band and the Balmer lines in ten stars with the best spectra, and we derive metallicities. Seven of them are in the range $-2.5 \leq$~[Fe/H]~$\leq -1.7$, while the others are less metal poor. If the stars are dwarfs, then they are at distances of 1 to 7~kpc, but if they are giants, typical distances will be about 10~kpc.Comment: (Plain Tex, 21 pages, including tables. Send email to 'travell_oir%[email protected]' for 12 pages of figures) To appear in the %%Astronomical Journal, August, 199

Interaction between graphene and SiO2 surface

With first-principles DFT calculations, the interaction between graphene and SiO2 surface has been analyzed by constructing the different configurations based on {\alpha}-quartz and cristobalite structures. The single layer graphene can stay stably on SiO2 surface is explained based on the general consideration of configuration structures of SiO2 surface. It is also found that the oxygen defect in SiO2 surface can shift the Fermi level of graphene down which opens out the mechanism of hole-doping effect of graphene absorbed on SiO2 surface observed in experiments.Comment: 17 pages, 7 figure

Technology acceptance among pre-service teachers: Does gender matter?

This study examined possible gender differences in pre-service teachers’ perceived acceptance of technology in their professional work under the framework of the technology acceptance model (TAM). Based on a sample of pre-service teachers, a series of progressively more stringent measurement invariance tests (configural, metric, and scalar invariances, as well as latent mean difference) were conducted. Practically, the findings revealed that, while the gender groups showed no statistical difference on perceived usefulness, attitudes toward technology, intention to use technology, female pre-service teachers had lower scores on perceived ease of use, suggesting that technology use is more challenging for female pre-service teachers than for their male counterparts. Technically, the findings provided support for full configural and metric invariance, and for partial scalar invariance. Discussions about the findings and their practical implications concerning teacher training are provided. Future research directions are also suggested

Solar modulation of cosmic ray intensity and solar flare events inferred from (14)C contents in dated tree rings

The delta 14C values in 42 rings of a white spruce grown in Mackenzie Delta was measured as a continuing effort of tracing the history of solar modulation of cosmic ray intensity. The delta 14C values in six rings were measured, in search of a 14C increase due to two large solar flares that occurred in 1942. The results are presented