Spin-dependent Quantum Interference in Single-Wall Carbon Nanotubes with Ferromagnetic Contacts

We report the experimental observation of spin-induced magnetoresistance in single-wall carbon nanotubes contacted with high-transparency ferromagnetic electrodes. In the linear regime the spin-induced magnetoresistance oscillates with gate voltage in quantitative agreement with calculations based on a Landauer-Buttiker model for independent electrons. Consistent with this interpretation, we find evidence for bias-induced oscillation in the spin-induced magnetoresistance signal on the scale of the level spacing in the nanotube. At higher bias, the spin-induced magnetoresistance disappears because of a sharp decrease in the effective spin-polarization injected from the ferromagnetic electrodes.Comment: Replaced with published versio

Measuring Performance in Public Sector Organizations: Evidence from Local Government Authorities in Tanzania

The aim of study was to assess the performance of Local government authorities in Tanzania. The study used balanced scorecard model as proposed by Kaplan and Norton (1992 to integrate financial and nonfinancial performance measures. This study modified the Kaplan and Norton (1992) balanced scorecard model by adding another performance perspective which is the social perspective. The finding of the study shows that the overall performance of Tanzanian local governments is poor with a performance level of 39.43% which is much contributed by poor financial performance rather than nonfinancial performance. Results indicate that there is a room to Tanzanian Local government authorities to improve both financial and nonfinancial performance through improvement in individual performance metrics in the future which will in turn improve overall performance. Given the advantages of balanced scorecard, it is recommended that LGAs should adopt balanced scorecard from their strategic point of view which will enable them to improve both financial and nonfinancial performance. Keywords: Local government authorities, social perspective, performance measurements, financial performance, non-financial performance, balance score car

The analytical discussion on strong gravitaional lensing for a gravitational source with a f(R)f(R) global monopole

Here the gravitational lensing in strong field limit of a Schwarzschild black hole with a solid deficit angle owing to global monopole within the context of the $f(R)$ gravity theory is investigated. We obtain the expressions of deflection angle and time delay in the forms of elliptic integrals and discuss the asymptotic behaviour of the elliptic integrals to find the explicit formulae of angle and time difference in the strong field limit. We show that the deflection angle and the time delay between multiple images are related not only to the monopole but also to the $f(R)$ correction $\psi_{0}$ by taking the cosmological boundary into account. Some observables such as the minimum impact parameter, the angular separation, the relative magnification and the compacted angular position have been estimated as well. It is intriguing that the tiny modification on the standard general relativity will make the remarkable deviation on the angle and the time lag, offering a significant way to explore some possible distinct signatures of the topological soliton and the correction of the Einstein general relativity.Comment: 11 pages, 5 figures. arXiv admin note: text overlap with arXiv:1004.342

Vowel and diphthong, development in Cantonese-speaking children aged 10 to 27 months

Also available in print."A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 4, 2001."Thesis (B.Sc)--University of Hong Kong, 2001published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Attitudes toward marriage and divorce in East Asia

Attitudes about marriage and divorce, which is related to cultural values and societal norms, are important as they can be indicators of couple relationship quality and marital stability. Along with the rapid social, economic, and cultural changes, East Asians have experienced the major transition of sociocultural interpretations of marriage and divorce. Using a person-oriented approach and the 2006 East Asian Social Survey data set (N = 9,035), this study explored if there were underlying groups of East Asians regarding attitudes toward marriage and divorce. Also, this study examined how those subgroup memberships differed on patriarchy, gender role ideology, age, gender, marital status, education level, and country. Four qualitatively different profiles were identified: conservative (10.8%), progressive (79.6%), married men less happy (3.1%), and married women less happy (6.5%). People in the conservative profile, where South Koreans accounted for 45.8%, were more likely to be older, currently married, and less educated. Individuals in the progressive profile were less likely to have traditional patriarchal and gender role ideology, and about 90% of Chinese and Japanese belonged to this profile. The characteristics of married men less happy and married women less happy group were similar to each other except for the gender ratio and gender role ideology. This study revealed that East Asians have different attitudes toward marriage and family by being categorized into four distinctive groups, which can be implications for policymakers and marriage educators in East Asia.Includes bibliographical reference

Bright 22 μ\mum Excess Candidates from WISE All-Sky Catalog and Hipparcos Main Catalog

In this paper we present a catalog which includes 141 bright candidates ($\leq10.27$ mag, V band) showing the infrared (IR) excess at 22 $\mu$m. Of which, 38 stars are known IR excess stars or disk, 23 stars are double or multiple stars and 4 are Be stars. While the remaining more than 70 stars are identified as the 22 $\mu$m excess candidates in our work. The criterion of selecting candidates is $K_s-[22]_{\mu m}$. All these candidates are selected from \emph{WISE} All-sky data cross-correlated with \emph{Hipparcos} Main Catalog and the likelihood-ratio technique is employed. Considering the effect of background, we introduce the \emph{IRAS} 100 $\mu$m level to exclude the high background. We also estimated the coincidence probability of these sources. In addition, we presented the optical to mid-infrared SEDs and optical images of all the candidates, and gave the observed optical spectra of 6 stars with NAOC's 2.16-m telescope. To measure for the dust amount around each star, the fractional luminosity is also provided. We also test whether our method of selecting IR excess stars can be used to search for extra-solar planets, we cross-matched our catalog with known IR-excess stars having planets but none is matched. Finally, we give the fraction of stars showing IR-excess for different spectral type of main-sequence stars.Comment: 45 pages, 16 figures, 4 tables. Accepted for publication in ApJ