Composition,distribution and habitat effects of vascular plants on the vertical surfaces of an ancient city wall

The vertical surfaces of walls accommodate diverse plants in urban areas. Characterizing species composition and distribution of plants growing in these habitats is of great significance towards a better understanding and management of urban ecosystems. Here we focused on the City Wall of Nanjing (CWN), one of the biggest and best reserved ancient masonry city walls in the world. Through detailed field survey, we investigated species composition, richness and cover of the vascular plants on the CWN, and examined their relationships with a set of local habitat factors including aspect, position, height of the wall and ground vegetation status, using canonical correspondence analysis and multiple regression models. In total we found 67 plant species on the CWN. They are mostly widespread ruderal plants, with a conspicuously high proportion of vine species. Surprisingly, we found that the investigated habitat factors generally have weak correlations (R ² < 10 %) with species composition, species richness and plant cover. The relationships remain weak when specified in different species groups in terms of life forms and seed dispersal traits. However, these species groups appear to have distinct responses to particular micro-habitat conditions such as light and intensity of human activities. Our results provide useful implications for protecting the walls and enhancing ecosystem services of their associated vegetation.

     

SPECIAL ISSUE： INCOME INEQUALITY IN CHINA Inter-industry Inequality： An Important Source of the Urban Income Gap--Regression-based Decomposition

基于回归方程的收入差距分解发现,1988年、1995年和2002年,行业间收入不平等对中国城镇居民收入差距的贡献越来越大,而且这主要是由一些收入迅速提高的垄断行业造成的。同时,区位、教育、所有制和职业类型以及是否有第二职业对收入差距的贡献也在提高,是否完全就业和年龄对收入差距的贡献明显下降。因此,缩小中国城镇收入差距,亟需打破劳动力市场进入壁垒和产品市场行业垄断。此外,减轻地区间的劳动力流动障碍、普遍提高劳动者的受教育水平等措施也将是未来政府缩小城镇收入差距的重要政策着力点。     

发展社会事业 努力改善民生

发展社会事业、改善民生关系人民幸福安康,关系国家兴衰成败,关系党的生死存亡。广州近年来为改善民生做了大量工作,人民生活水平不断提高,具备加快发展社会事业、改善民生的物质基础和条件。围绕人民群众最关心、最直接、最现实的利益问题,目前突出抓好促进教育公平均衡优质发展、提高医疗卫生服务水平、促进就业稳定增长、全面改善人居环境、加快完善社会保障体系、着力提高住房保障水平、加强社会治安综合治理、切实解决交通拥堵问题、推动文化建设繁荣发展等九方面工作。为了做好这些工作,要按照科学发展观要求,坚持做到＂五个统筹＂,即统筹经济社会发展、统筹城乡发展、统筹经济增长与居民增收、统筹文化建设与城市建设和统筹政府主导与社会参与等。     

略论多学科视角下的医疗保险理论研究

医疗保险理论建立在医学、社会学、经济学、政治学等多学科基础理论之上,其中社会学的社会风险、社会变迁与社会权利理论揭示了健康风险演化与医疗保险产生的基本路径,并为医疗保险基本理念与目标奠定了理论基础;经济学的信息不对称理论、博弈论为医疗保险制度的设计提供了基本方法;政治学关于政党理论的探讨则揭示了当前医疗保险改革的政策困局.从社会学、经济学和政治学的多学科视角出发,探讨医疗保险的理念、目标、模式和评估机制,能为构建我国医疗保险的理论分析框架提供启示.     

城乡基本公共产品需求比较研究

目前我国已经进入公共产品需求快速扩张时期,人们对满足吃穿的温饱需求已开始转为对教育、医疗、卫生等基本公共产品的需求.为了更好统筹城乡公共产品供给,充分满足城乡居民的需求,有必要了解城乡居民对公共产品的需求状况,并对其进行比较,以居民需求导向为依据,建立和完善我国基本公共产品供给体系.     

橡胶颗粒改性沥青混合料室内试验研究

成人高等教育在学历教育逐渐萎缩的情况下积极开拓非学历教育空间,取得明显效果。然而,目前成人教师队伍的现状已不能很好地适应这种转变,在一定程度上影响了成人教育的教学质量,应逐步从调整成人教师结构组成、加强教师培训力度、丰富教师考核内容、制定教师资格证书几方面入手,培养建立一支合格的专业的成人教师队伍,从而保证成人高等教育的教学质量不断提高,更好适应经济社会发展需要。     

On batch queueing systems: A combinatorial approach

We consider batch queueing systems M/M^H/1$M/M^H/1$ and M^H/M/1$M^H/M/1$ with catastrophes. The transient probability functions of these queueing systems are obtained by a Lattice Path Combinatorics approach that utilizes randomization and dual processes. Steady state distributions are also determined. Generalization to systems having batches of different sizes are discussed.     

Near-Optimal Conflict-Free Channel Set Assignments for an Optical Cluster-Based Hypercube Network

Recently a class of scalable multi-star optical networks is proposed. Inthis network class nodes are grouped into clusters. Each cluster employs aseparate pair of broadcast and select couplers. The clusters areinterconnected via fiber links according to a regular topology. This approachefficiently combines time and/or wavelength division with direct spacedivision. One important issue for this network class is the conflict-freechannel set assignment that maximizes spatial re-use of channels. This paperstudies the conflict-free channel set assignment for the hypercube clusterinterconnection topology. The approach in this paper is novel and isconjectured to be optimal.     

西部大开发中少数民族高等教育发展趋势

我国少数民族主要分布和集中在西部地区,发展民族高等教育,不仅对西部地区的经济社会发展起到重要作用,而且对国家的统一,民族团结,社会的稳定都具有重大战略意义.本文结合贵州民族学院的实际,对西部大开发中少数民族高等教育发展问题进行探讨.     

Discrimination between the binomial and hypergeometric models

This paper examines the problem of discerning whether sampling is being done with or without replacement. It is shown that with just one sample in the absence of additional information only a rather trivial solution is possible. For replicated samples, method of moments and graphically oriented procedures are considered. A simulation study reveals that there appears to be little advantage to employing any more sophisticated approach than the method of moments.