On the linear complexity of Sidel'nikov Sequences over Fd

We study the linear complexity of sequences over the prime field Fd introduced by Sidel’nikov. For several classes of period length we can show that these sequences have a large linear complexity. For the ternary case we present exact results on the linear complexity using well known results on cyclotomic numbers. Moreover, we prove a general lower bound on the linear complexity profile for all of these sequences. The obtained results extend known results on the binary case. Finally we present an upper bound on the aperiodic autocorrelation

A range extension for Haplomitrium mnioides (Lindb.) R.M.Schust.

Haplomitrium mnioides (Lindb.) R.M.Schust. is reported as new to Hainan Island. A continuous distribution of H. mnioides from west (Thailand) to east (Japan) is confirmed. Habitat pictures and a distribution map are provided

Two new species and one new combination of Helina Robineau-Desvoidy, 1830 (Diptera: Muscidae) from China

Two new species of the genus Helina Robineau-Desvoidy, 1830 from Sichuan, China are described and illustrated, i.e. Helina fulvibasicosta Ming-Fu Wang sp. n. and Helina flavipes Ming-Fu Wang&Chen Sun sp. n. After re-examining the holotype, Helina occidentalisinica Feng, Shi & Li, 2005 is transferred to the genus Hebecnema Schnabl

FFT-LB modeling of thermal liquid-vapor systems

We further develop a thermal LB model for multiphase flows. In the improved model, we propose to use the FFT scheme to calculate both the convection term and external force term. The usage of FFT scheme is detailed and analyzed. By using the FFT algorithm spatiotemporal discretization errors are decreased dramatically and the conservation of total energy is much better preserved. A direct consequence of the improvement is that the unphysical spurious velocities at the interfacial regions can be damped to neglectable scale. Together with the better conservation of total energy, the more accurate flow velocities lead to the more accurate temperature field which determines the dynamical and final states of the system. With the new model, the phase diagram of the liquid-vapor system obtained from simulation is more consistent with that from theoretical calculation. Very sharp interfaces can be achieved. The accuracy of simulation results are also verified by the Laplace law. The FFT scheme can be easily applied to other models for multiphase flows.Comment: 34 pages, 21 figure

The open cluster NGC6823 and possible triggered star formation associated with SNR G59.5+0.1

We investigate the environment in the vicinity of the supernova remnant (SNR) G59.5+0.1 and identify all young stellar objects (YSOs) around the SNR, to derive the physical properties, obtain insight into the star-formation history, and further see whether SNR G59.5+0.1 can trigger star formation in this region. We have performed the submillimeter/millimeter observations in CO lines toward the southeast of SNR G59.5+0.1 with the KOSMA 3m Telescope. High integrated CO line intensity ratio R(CO 3-2/CO 2-1) is identified as one good signature of SNR-MCs (molecular clouds) interacting system. To investigate the impact of SNR G59.5+0.1 on the process of star formation, we used GLIMPSE I Catalog to select YSOs (including class I and class II sources). CO emission in an arc-like shape and mid-infrared 8.28 um emission are well coincident with SNR G59.5+0.1, which has the total mass of 1.1*10^{4}Msun and fully cover open cluster NGC 6823. Three molecular clumps were identified in the CO molecular arc, each clump shows the broad line wing emission, indicating that there are three outflows motion. The integrated CO line intensity ratio (R(CO 3-2/CO 2-1) for the whole molecular arc is between 0.48 and 1.57. The maximum value is 1.57, which is much higher than previous measurements of individual Galactic MCs. The CO molecular arc has a line intensity ratio gradient. SNR G59.5+0.1 is in adiabatic expansion phase. The age of the SNR is 8.6*10^{4} yr. Based on GLIMPSE I Catalog 625 young stellar objects (YSOs) candidates (including 176 class I sources and 449 class II sources) are selected. The timescales for class 0, class I and class II sources are <10^{4} yr, ~10^{5} yr, and ~10^{6} yr, respectively. The number of YSOs are significantly enhanced in the interacting regions, indicating the presence of some recently formed stars.Comment: 7 pages and 9 figures, Accepted for publication by A&

Lattice Boltzmann Approach to High-Speed Compressible Flows

We present an improved lattice Boltzmann model for high-speed compressible flows. The model is composed of a discrete-velocity model by Kataoka and Tsutahara [Phys. Rev. E \textbf{69}, 056702 (2004)] and an appropriate finite-difference scheme combined with an additional dissipation term. With the dissipation term parameters in the model can be flexibly chosen so that the von Neumann stability condition is satisfied. The influence of the various model parameters on the numerical stability is analyzed and some reference values of parameter are suggested. The new scheme works for both subsonic and supersonic flows with a Mach number up to 30 (or higher), which is validated by well-known benchmark tests. Simulations on Riemann problems with very high ratios ($1000:1$) of pressure and density also show good accuracy and stability. Successful recovering of regular and double Mach shock reflections shows the potential application of the lattice Boltzmann model to fluid systems where non-equilibrium processes are intrinsic. The new scheme for stability can be easily extended to other lattice Boltzmann models.Comment: Figs.11 and 12 in JPEG format. Int. J. Mod. Phys. C (to appear

Three new species of the genus Drymeia Meigen (Diptera: Muscidae) from the Qinghai-Xizang (Tibet) Plateau, China

Three new species of Drymeia are described from Qinghai-Xizang (Tibet), China: Drymeia fimbricauda Xue, sp. n., Drymeia katepimeronipilosa Xue, sp. n. and Drymeia quadratimacula Xue, sp. n. The type specimens of the new species are deposited in the Institute of Entomology, Shenyang Normal University. In addition, a generic diagnosis of Drymeia is given, and five species assigned to the genus Drymeia Meigen in Flies of China are transferred to the genus of Spilogona Schnabl. In the genus Drymeia, 48 species are now known from China. The effects of the uplift of the Qinghai-Xizang (Tibet) Plateau on the structural diversity of Drymeia species are discussed

Relations between a Country and a Continent: China and Africa. A first and not a simple matter......

Through this contribution of a geopolitical approach, the author intends to propose an updated and accurate framework on the relations between China and Africa as well as some critical reflections on various geopolitical and geo-economic aspects concerning the intense development of the diversified economic relations between China and the different African States. China's foreign economic policy in Africa has laid solid foundations through the implementation of the various Sino-African Cooperation Forums that have taken place since 2000 and that have seen an increasing involvement of the Chinese government in the process. This paper intends to make a brief reflection on China's visible economic and geopolitical interest in the African Continent as a whole. The analysis that follows traces the main stages in the history of relations between China and Africa, emphasizing the increased importance of the Sino-African forums that led to what is now known as Chinese neo-colonization. In addition, the case studies of the Silk Road and the Rare Lands are highlighted. Finally, some of the social impacts of the Chinese presence in Africa are also examined such as the construction of new cities for the Chinese migrant population and the teaching of the Chinese language (Mandarin) in schools in some African Countries

Notes on five, mainly high-altitude species of Chinese Neckera, with an updated key to Neckera sensu lato in China

This paper presents new distributional records of five Chinese species of Neckera Hedw.: N. bhutanensis Nog. (new to Sichuan and Yunnan), N. borealis Nog. (new to Xinjiang), N. himalayana Mitt. (Yunnan, new to China), N. setschwanica Broth. (new to Bhutan), and N. xizangensis Enroth (new to Sichuan and Yunnan, the first reports of the species since type material from Xizang). Maps showing the distributions of the treated species in China and an updated key to the Chinese species of Neckera sensu lato are provided.Peer reviewe