Pile and pile group response to tunnelling using a large diameter slurry shield – Case study in Shanghai

The study investigates the disturbance to piles and pile groups caused by multiple nearby drives of a large diameter slurry shield-driven tunnelling machine in Shanghai. The minimum distance between the slurry shield tunnel (with diameter D = 15.43 m) and the adjacent pile groups of Metro Line 3 and Yixian Elevated Road is 1 m. The nonlinear finite element (FE) software program ABAQUS was used to analyse the movement of the pile groups caused by the process of shield tunnelling. A field investigation was conducted before the multiple crossings to study the impact (movement and excess pore water pressure) on the surrounding soil and piles caused by the tunnelling process. The field investigation is divided into two sections: (i) free-field tunnelling, and (ii) tunnelling close to trial piles pre-installed in the section. For the full-scale test, tunnelling variable, including slurry pressure and grouting pressure, are adjusted during construction to reduce the disturbance during tunnelling close to pile groups supporting two elevated bridges. The FE simulation of the multiple crossings includes two steps: (a) shield tunnelling along the south bound tunnel approaching the working shaft at the western bank of the Huangpu River, and passing separately between two adjacent pile groups of each bridge; (b) return tunnel passing again between the pile groups of the two bridges along the north bound tunnel. Three different FE models are generated: (1) free-field tunnelling process, (2) tunnelling close to trial piles, and (3) multiple tunnel passes adjacent to pile groups supporting the two elevated bridges. Most of the relevant factors in tunnelling are taken into consideration in the FE models including (a) slurry pressure, (b) grouting pressure, (c) grouting material hardening, and (d) soil-pile interaction.     

A kinematic study of M51-type galaxies

Spectroscopic observations of twelve M51-type binary galaxies with the 6-m Special Astrophysical Observatory telescope are presented. We constructed the rotation curves for the primary galaxies of each binary system and determined the line-of-sight velocities of their companions from the Hα and [N II] 6583 Å emission lines.     

The Missing Intermediate Luminosity Galaxies in the Leo I Group

We present results from a large scale R-band survey of the nearby Leo I group to measure the luminosity function down to dwarf spheroidal luminosities and surface brightnesses. This program has utilized>7 square degrees of imaging with the Mosaic camera at the KPNO 0.9mand extensive, on-going spectroscopic follow-up. We estimate our completeness from simulations to be 90% at μ_R(0) ≃ 24.5, M _R ≃ –11.Leo I is a nearby, low-density group for which a steep faint-end slope has been suggested (Ferguson and Sandage, 1991).We find the luminosity function to be more similar to that of the Local Group at the faint-end (flat).We also find an unusual gap in the luminosity function at intermediate luminosities, –19.5 < M _R < –16. This gap cannot be explained by pure Poisson fluctuations around a typical Schechter function, nor is it likely to result from photometric incompleteness. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Ursa Major supercluster of galaxies: II. The structure and peculiar velocities

Kormendy’s relation (μ_e-logR _e) is used to investigate the structure of the compact Ursa Major supercluster of galaxies (11^h30^m+55°, cz=18 000 km s^?1); this relation allows the distances of early-type galaxies to be estimated. The relative distances of 13 clusters in the supercluster and their peculiar velocities are determined with a mean statistical accuracy of 6%. In general, the supercluster obeys the Hubble relation between radial velocity and distance. However, there is reason to suggest that the supercluster consists of two subsystems with mean radial velocities of 16 200 and 19 700 km s^?1. For a velocity dispersion in the subsystems of ～1100 km s^?1, the fact that each of them is gravitationally bound is not ruled out.     

Correlation properties of the galaxies in the Local Supercluster

The apparatus of a correlation gamma function is used to analyze the spatial clustering of galaxies in the Local Supercluster. In particular, we analyzed a sample corrected for the peculiar velocities of the Local Supercluster galaxies by using our original technique for separating groups of galaxies. It turned out that the peculiar velocities did not significantly distort the gamma function even for relatively small sample sizes. The distribution of the galaxies obeys a power-law decrease in density with an index of 0.6–0.7. We found evidence for a luminosity dependence of the degree of galaxy clustering within the volume under study.     

Indigenous Knowledge on Soil Classification of Ethnic Groups in Luang Prabang Province of the Lao PDR

Introduction Traditional agriculture based on indigenous knowledge (IK) has been practiced in many areas for centuries. Such practices are often the basis of very sustainable technologies, which are potentially suitable for developmental programs. Polthanee (2001) reported that such farmer practices have been repeatedly found to be valid, rational and usually suited to the local environmental conditions. Moreover, with increased under- standing of agro-ecosystems, professionals in agricultura…     

群的根性的一个问题

假设（R）是群的根性,N是群G的正规子群,记N^-/N＝RR（G/N）.主要利用群的根性的性质来解决哪种根性具有特征性质N1N2^-＝N1^-N2^-这个问题.     

REPRESENTATION OF STATISTICAL PROPERTIES OF WAVE GROUPS FOR SEA PROCESSES WITH DOUBLE-PEAKED SPECTRA

A method using group-induced second-order long waves(GSLW) to represent statistical properties of wave groups with double-peaked spectra is put forward in this paper on the basis of the GSLW theory. The GSLW is regarded as a weighted linear superimposition of the second-order long Wave induced by the low peak frequency section and that induced by the high peak frequency section. There is a parabolic relationship between the GSLW and the wave envelope. Then the probability density function and the distribution function of the GSLW amplitude are derived. Thus the formulas for the average time duration and the mean length of runs can be derived. Good agreement between theoretical results and measured values was achieved. as verified with the measured double-peaked spectra in different regions.     

Optical studies of extragalactic infrared sources

We present spectroscopic observations of 41 galaxies with the 6-m telescope, 31 of which are the optical counterparts of IRAS PSC infrared sources. Redshifts and activity types are provided.     

小黄鱼Larimichthys polyactis体长-体重关系幂指数与产卵群体空间分布相关性研究

鱼类产卵群体的相关研究一直是渔业领域关注的热点,对鱼类的产卵期、产卵场的研究是鱼类生态习性研究方向的重要组成部分。本文在前期研究证实鱼类体长-体重关系幂指数可以指示鱼类产卵期的基础上,利用2004年4个季节的东海大面积调查数据,尝试利用同一时间点上的各个调查点幂指数信息来分析鱼类产卵场分布特征,结果发现,成熟产卵个体仅在春季出现,而未成熟产卵个体4季均有分布,以此推测小黄鱼存在"跳过产卵"现象。另外发现,单靠幂指数大小,不能区分各个产卵成熟阶段,也不能区分产卵个体与非产卵个体;而怀卵个体出现站点的幂指数平均值偏低于匀速生长,空间上也具有类似特征,即幂指数相对低的地方一般对应怀卵个体相对集中的水域。本文依据幂指数分布,推断小黄鱼成熟产卵群体有3块相对集中水域,即舟山渔场近海、济州岛西南侧和江外与舟外渔场临近水域。