The abundance and radial distribution of satellite galaxies

Using detailed mock galaxy redshift surveys (MGRSs) we investigate the abundance and radial distribution of satellite galaxies. The mock surveys are constructed using large numerical simulations and the conditional luminosity function (CLF), and are compared against data from the Two Degree Field Galaxy Redshift Survey (2dFGRS). We use Monte Carlo Markov chains to explore the full posterior distribution of the CLF parameter space, and show that the average relation between light and mass is tightly constrained and in excellent agreement with our previous models and with that of Vale & Ostriker. The radial number density distribution of satellite galaxies in the 2dFGRS reveals a pronounced absence of satellites at small projected separations from their host galaxies. This is (at least partly) owing to the overlap and merging of galaxy images in the 2dFGRS parent catalogue. Owing to the resulting close-pair incompleteness we are unfortunately unable to put meaningful constraints on the radial distribution of satellite galaxies; the data are consistent with a radial number density distribution that follows that of the dark matter particles, but we cannot rule out alternatives with a constant number density core. Marginalizing over the full CLF parameter space, we show that in a ΛCDM concordance cosmology the observed abundances of host and satellite galaxies in the 2dFGRS indicate a power spectrum normalization of  σ₈≃ 0.7  . The same cosmology but with  σ₈= 0.9  is unable to match simultaneously the abundances of host and satellite galaxies. This confirms our previous conclusions based on the pairwise peculiar velocity dispersions and the group multiplicity function.     

马氏珠母贝激光育苗的生物学机理

对马氏珠母贝激光育苗的机理进行研究，结果表明：激光能加强精子活力，提高精液品质；影响卵子的通透性；抑制水中的细菌生长，使受精卵发育成健壮的胚胎、幼虫、幼苗。     

VARIATIONAL ITERATION SOLVING METHOD FOR SEA-AIR OSCILLATOR MODEL OF INTERDECADAL CLIMATE FLUCTUATIONS

1IN T R O D U C T IO NInteractionsbetween the ocean and atmosphere con-tributeto climatefluctuationosver a broad spectrum oftime scales.Studiesof those interactionhsave farfo-cused on El Ni o-SouthernOscillation(ENSO)phe-nomenon thathas a period of3to4yea…     

Coronal expansion and the transfer of solar angular momentum to the interplanetary space

We discuss the question of loss of angular momentum through coronal expansion. From a large volume of data on Type-1 cometary tails we have confirmed the presence of a tangential component in the coronal expansion, which has not only a stochastic component but also a constant component of 9.8 km/s. Through coronal expansion the Sun has lost 80% of its angular momentum since it evolved on to the main sequence and the angular velocity of the Sun is decreasing exponentially. This result should have a large effect on the dynamical evolution of the Sun.     

Aspherical accretion of cosmic strings

A simulation of accretion of a string loop has been done. It shows that aspherical accretion is essential for large-scale loops. All configurations found in the distribution of galaxies, such as filaments, pancakes, bubbles, and voids, can be formed by the accretion of cosmic strings.     

Geochemical discriminations of sandstones from the Mohe Foreland basin,northeastern China: Tectonic setting and provenance

The Mohe region near the border area of China with Russia is in Heilongjiang Province. Topographically the area consists of lower mountains or hills situated at the northern end of the Da Hinggan Mountains. Struc-turally the Mohe basin rests on the north margin of the Ergun Block, and the Mongol-Okhotsk Orogen is lo-cated to the north of the basin. Due to poor access conditions and good vegetation coverage, previous researches on the basin are much weak with few spe-cial geological inves…     

广西右江河谷2008年芒果低温寒害调查分析

通过对广西右江河谷四县(区)2008年低温期间气象要素资料、气候特点进行分析统计,结合芒果的生物学特性、物候发育期及农业气象灾害指标,探讨此次低温寒害天气对右江河谷芒果生产的影响,并提出相应的生产防御对策,以达到趋利避害.