Theory for superconductivity in alkali chromium arsenides A2Cr3As3 (A=K,Rb,Cs)

We propose an extended Hubbard model with three molecular orbitals on a hexagonal lattice with $D_{3h}$ symmetry to study recently discovered superconductivity in A$_2$Cr$_3$As$_3$ (A=K,Rb,Cs). Effective pairing interactions from paramagnon fluctuations are derived within the random phase approximation, and are found to be most attractive in spin triplet channels. At small Hubbard $U$ and moderate Hund's coupling, the pairing arises from 3-dimensional (3D) $\gamma$ band and has a spatial symmetry $f_{y(3x^{2}-y^{2})}$, which gives line nodes in the gap function. At large $U$, a fully gapped $p$-wave state, $p_{z}\hat{z}$ dominates at the quasi-1D $\alpha$-band

Estimating Markov-Switching ARMA Models with Extended Algorithms of Hamilton

This paper proposes two innovative algorithms to estimate a general class of N-state Markov-switching autoregressive moving-average (MS-ARMA) models with a sample of size T. To resolve the problem of NT possible routes induced by the presence of MA parameters, the first algorithm is built on Hamilton’s (1989) method and Gray’s (1996) idea of replacing the lagged error terms with their corresponding conditional expectations. We thus name it as the Hamilton-Gray (HG) algorithm. The second method refines the HG algorithm by recursively updating the conditional expectations of these errors and is named as the extended Hamilton-Gray (EHG) algorithm. The computational cost of both algorithms is very mild, because the implementation of these algorithms is very much similar to that of Hamilton (1989). The simulations show that the finite sample performance of the EHG algorithm is very satisfactory and is much better than that of the HG counterpart. We also apply the EHG algorithm to the issues of dating U.S. business cycles with the same real GNP data employed in Hamilton (1989). The turning points identified with the EHG algorithm resemble closely to those of the NBER’s Business Cycle Dating Committee and confirm the robustness of the findings in Hamilton (1989) about the effectiveness of Markov-switching models in dating U.S. business cycles.Markov-switching, ARMA process

\Lambda_b Lifetime from the HQET Sum Rule

The HQET sum rule analysis for the \Lambda_b matrix element of the four-quark operator relevant to its lifetime is reported. Our main conclusion is that the lifetime ratio \tau(\Lambda_b)/\tau(B^0) can be as low as 0.91.Comment: 5 pages, latex, no figures, uses sprocl.sty (included). Talk by C. Liu at Int. Conf. on Flavor Phys., Zhang-Jia-Jie, 31/5-6/6 200

A Novel Three-Point Modulation Technique for Fractional-N Frequency Synthesizer Applications

This paper presents a novel three-point modulation technique for fractional-N frequency synthesizer applications. Convention modulated fractional-N frequency synthesizers suffer from quantization noise, which degrades not only the phase noise performance but also the modulation quality. To solve this problem, this work proposes a three-point modulation technique, which not only cancels the quantization noise, but also markedly boosts the channel switching speed. Measurements reveal that the implemented 2.4 GHz fractional-N frequency synthesizer using three-point modulation can achieve a 2.5 Mbps GFSK data rate with an FSK error rate of only 1.4 %. The phase noise is approximately -98 dBc/Hz at a frequency offset of 100 kHz. The channel switching time is only 1.1 μs with a frequency step of 80 MHz. Comparing with conventional two-point modulation, the proposed three-point modulation greatly improves the FSK error rate, phase noise and channel switching time by about 10 %, 30 dB and 126 μs, respectively

Condensate wave function and elementary excitations of bosonic polar molecules: beyond the first Born approximation

We investigate the condensate wave function and elementary excitations of strongly interacting bosonic polar molecules in a harmonic trap, treating the scattering amplitude beyond the standard first Born approximation (FBA). By using an appropriate trial wave function in the variational method, effects of the leading order correction beyond the FBA have been investigated and shown to be significantly enhanced when the system is close to the phase boundary of collapse. How such leading order effect of going beyond the FBA can be observed in a realistic experiment is also discussed.Comment: 7 pages, 4 figure

The Influence of the Translators’ Theology on Bible Translation: A Comparative Study of the Chinese Union Version and the Chinese Recovery Version of the New Testament

The influence of theology on Bible translation is a phenomenon that has been increasingly acknowledged by Bible translation scholars in recent decades, yet for various reasons including the long-established secular-sacred divide in modern academia, it has remained an underexplored subject in both the fields of Translation Studies (TS) and biblical translation studies (BTS). To address this gap, this study is the first study that examines the influence of the translators’ theology on Bible translation by a comparative study of two New Testament translations in their entirety, and it is also the first study of this kind on both the Chinese Union Version (CUV) and the Chinese Recovery Version (CRV), with the CUV being the most popular and influential Chinese Bible over the last hundred years. By adopting a new theoretical framework for studying theological influence in Bible translation, by following a methodology that minimizes the researcher’s subjectivity and overcomes the difficulties inherent in such a study, and by analyzing and presenting the empirical findings according to the main subjects of systematic theology, this study discovered that the translators’ understandings of what God’s overall plan is for mankind exerted the most dominant and overarching influence on their Bible translations in the cases of the CUV and the CRV. Besides revealing many other new insights concerning how the translators’ theology may influence Bible translation, this study also offers both methodological and theoretical contributions to the fields of BTS and TS, illuminates the way and importance of conducting similar studies on other Bible translations, points to the need of charting a new sub-field called ‘biblical translator studies’, and shows that to understand and speak about any Bible translation, we must thoroughly understand the translators’ theology

Biodiversity shapes tree species aggregations in tropical forests

Spatial patterns of conspecific trees are considered as the consequences of biological interactions and environmental influences. They also reflect species interactions in plant communities. However, biological attributes are often neglected while deliberating the factors shaping species distributions. As rising attentions are paid to spatial patterns of tropical forest trees, we noticed that seven Center of Tropical Forest Sites and four Forest Dynamic Plots in Asia and America have presented analogously high proportions of species with aggregated conspecific individuals coincidently. This phenomenon is distinctive and repudiates fundamental ecology hypotheses which suggested dispersed distributions of conspecific tropical trees due to intensive density and natural enemy pressures in tropical forests. We believe that similar aggregation patterns shared by these tropical forests implies the existence of structuring forces in biogeographical scale instead of habitat heterogeneity in local community scales as scientists have considered. To approach the factors contributing to this cross-continent spatial pattern of trees, we obtained and reviewed ecosystem attributes, including topography, temperature, precipitation, biodiversity, density, and biomass, of these forests. Here we show that the proportions of aggregated species are actually constants independent of any ecosystem attributes regardless the nature of these tropical forests. However, local biodiversity are the major factor determining the number of aggregated species and the aggregation of large individuals of these forests. Aggregation of large trees declines along rising biodiversity, while the numbers of aggregated species increase permanently along lifting biodiversity. We propose a possible equilibrium and saturated status of the tropical forests in accommodating aggregated species. Furthermore, the tight correlations of biodiversity and species aggregation strongly imply the importance of overlooked biological interactions in shaping the spatial patterns in the tropical forests