岩土边坡稳定性分析方法综述

文章对现有边坡稳定性分析方法进行了综述，总结了各种边坡稳定性分析方法的优缺点及其适用范围。目前，极限平衡法仍在工程中广泛应用，随着计算机技术的兴起，数值分析法是未来发展的趋势。     

淮海城市群的城市中心性分析

从生产、商贸、信息、交通、科教、金融、医疗和文化8个方面建立起城市中心性综合评价指标体系,运用熵值法和首位度等相关方法,以地级市区为研究单元,对2012年淮海城市群内主要城市的中心性、规模分布和区域差异进行定量分析。结果发现：徐州是淮海城市群的首要中心城市,在生产、商贸、交通、科教、金融和医疗方面的中心性最强,但其首位分布并不显著。徐州的城市中心性不显著,且与临沂、济宁、连云港差距较小。     

芦溪县乡村传统民俗文化现状的调研与思考

为挖掘、保护、传承和管理芦溪乡村传统民俗文化,我们对其现状进行摸底调研,结果表明:婚丧文化成为芦溪乡村普遍流行的民俗文化;节庆文化是村民最感兴趣,它最能丰富村民生活、能传递正能量;宗教文化在村民中亦有不可小觑的影响力,民间戏曲文化和民谣文化成为了最能推动乡村旅游的"排头兵";祠堂、谱牒文化在一定程度上能维护乡村安定团结;医筮文化和命相文化在调查中被认为是消极作用最大的乡村传统文化。摸底调研对弘扬优秀民俗文化,建设和谐秀美芦溪乡村有一定的促进作用。     

Variation of satellite transponder delay

For precise orbit determination of geosynchronous earth orbit(GEO)satellites using transfer ranging observations,it is generally assumed that the variation of the satellite transponder delay is very small and that it can be solved as a constant parameter together with satellite orbit parameters.However,this assumption is too general and it reduces the accuracy of orbit determination for GEO satellites.To study and analyse the impact of the satellite transponder delay on GEO satellites orbit determination,two schemes were proposed.First,the satellite transponder delay was eliminated by forming single-difference observations between two ground stations;second,the satellite transponder delay was described as a constant parameter.The preliminary results demonstrate a difference of about1–2 m between the two schemes when used for precise orbit determination of GEO satellites.By fixing the GEO satellite orbit and other relevant parameters estimated by single-difference model,we inversed the instantaneous transponder delay from non-difference observation.It was found that the satellite transponder delay has a distinct diurnal variation,with an amplitude of 3–4 m.The findings of this paper are helpful in establishing an accurate model of satellite transponder delay and in improving the accuracy of GEO satellites orbit determinations and predictions.     

Paleoclimate change recorded in the red earth and brown-yellow sediment of Late Quaternary for northeastern part of Guangdong Province, south to the Nanling Mountains, China

The paleoenvironment indicated by the geochronology, major oxides SiO2, Al2O3 and TOFE （Fe2O3 ＋ FeO）, and CIA （Chemical Index of Alteration） value of the red earth and brown-yellow silt primarily characterized by the Linjiang stratigraphic section, based on the geological investigation of Late Quaternary along the river banks of northeastern part of China＇s Guangdong Province, south to the Nanling Mountains, allow us to hypothesize that the red earth on the first terrace in northeastern part of Guangdong belongs to reticulated red clay developed in a hot-wet environment of the last interglacial period （132-73 ka BP）, similar to the monsoon environment in the northern margin of modern tropical zone, while the overlying brown-yellow silt layer mainly accumulated in a monsoon environment of warm temperate zone in the last glacial period （73-11 ka BP）, with the aeolian sand LJ3 representing an extreme period of worsening climate. Such a hypothesis corresponds well with predecessors＇ research on the paleoenvironment indicated by abundant fossils in both south and east to the Nanling Mountains. Hence, it follows that the bioclimatic zone did experience a large and rapid vicissitude in northeastern part of China＇s Guangdong Province, and even in the full extent of the region south to the Nanling Mountains from the last interglacial period to the last glacial period, with the red earth being replaced by the brown-yellow silty sediment, and even maybe with the Ailuropoda-Stegodon Fauna being replaced by the Penghu Fauna. This study may provide an important geological demonstration for the environmental response to global change in China＇s low latitudes on a 10 ka scale.     

企业虚拟营销战略探讨

随着经济全球化时代的到来,网络技术的日趋完善,企业的营销环境呈现出了新的特点,新的市场营销形态——虚拟营销已经悄然出现。文章研究了虚拟营销的特点,分析了其在当今经济环境中竞争优势和运作规律,提出了我国出口企业要取得强有力的竞争力应采取的措施。     

Optimal carrier-smoothed-code algorithm for dual-frequency GPS data

Carrier-smoothed-code (CSC) algorithm is an effective pseudorange multipath mitigation technique, which can alleviate the computational burden and reduce the communication bandwidth needed for the transmission of GPS observations. This paper presents an improved Hatch filter and address the optimal CSC algorithm for dual-frequency GPS data based on the optimal parameter estimation theory. The smoothed observations have the same information content as that of the raw dual-frequency GPS data from which they are derived. Consequently, the optimal CSC algorithm is equivalent to the uncombined algorithm. Theoretical analyses show that the data precision of the optimal CSC algorithm is better than that of Hatch filter and its improved version.     

交换环上一类矩阵半群的自同构

设R是有单位元的交换环,Tn（R）是由R上所有的n×n上三角矩阵组成的乘法半群．本文将决定Tn（R）上的所有自同构．     

Effects of ambient air pollution on allergic rhinitis among preschool children in Changsha, China

Prevalence of allergic rhinitis has rapidly increased among Chinese children,but the reasons are unclear.Recent findings have suggested that exposure to outdoor air pollutants may increase the risk of allergic rhinitis,but the results were inconsistent.This study further investigated the effect of outdoor air pollutants on allergic rhinitis among preschool children.A standardized questionnaire on health,home and environmental factors was conducted for 4988 children aged 1–8 in the city of Changsha,and the concentrations of PM10(particle diameter 10 m),sulfur dioxide(SO2)and nitrogen dioxide(NO2)during 2006–2011 were acquired from the official web of Changsha Environmental Protection Agency.Results showed that the prevalence of children’s doctor diagnosed rhinitis was 8.4%(95%confidence interval[CI]7.0%–10.0%).It was found that the prevalence of rhinitis was not associated with site-specific background concentrations of air pollutants,but significantly positively correlated with age-related accumulative personal exposure of PM10,SO2and NO2.We conclude that age-related accumulative personal exposure to ambient air pollution may play an important role in the development of rhinitis.     

基于AQWA的张力腿平台动力响应分析

为研究极端海况下张力腿平台(TLP)的动力响应性能,对一典型传统式TLP平台进行整体设计,并应用势流理论和波浪的辐射/衍射理论,结合水动力分析软件AQWA,考虑随机波浪载荷及风、流载荷的共同作用,对平台在极端海况下的动力响应进行了数值模拟分析,计算在多个不同入射角波浪作用下的平台六个自由度上运动的幅值响应算子(RAOs),模拟分析在极端海况P-M波浪谱作用下平台的动力响应和张力腿的运动响应.结果表明:波浪入射角的不同对平台垂荡运动的RAOs没有明显的影响,对另外5个方向运动RAOs的幅值有明显影响;张力腿提供的附加刚度,对平台上体纵、横摇及垂荡响应作用明显,对平台纵、横荡及首摇也有一定的限制作用;平台的动力响应主要由波浪荷载引起;张力腿在平台上体带动及流荷载作用下会产生较大幅度运动.总之,在张力腿的有效约束下TLP平台可以避开能量集中的波浪频率,表现出良好的纵、横摇及垂荡性能,而张力腿的安全和性能将成为平台安全和性能的重要指标.