古罗马剧场建筑特色及其形成原因和影响

古罗马在整个人类历史上不仅仅是一个地理概念,它还代表着一个帝国、一种文化、一种传统。与人类其他辉煌的文明相比,罗马的伟大正是其将文明的发展植根于世俗,反映在建筑上则是娱乐性建筑的大量涌现。剧场作为标志性的娱乐性建筑,反映了帝国时期罗马的伟大成就,更体现出古罗马人当时的社会生活状态和精神状态。本文尝试对古罗马剧场典型特色进行一定分析研究,并在此基础上从物质层面、经济层面、文化层面归纳出古罗马剧场建筑特色形成的原因,以及其对后世建筑思想与建筑实践的影响。     

Classification of full-polarization ALOS-PALSAR imagery using SVM in arid area of Dunhuang

Classification is an important process in interpretation of synthetic aperture radar(SAR) imagery. As an advanced instrument for remote sensing, the polarimetric SAR has been applied widely in many fields. The main aim of this paper is to explore the ability of the full-polarization SAR data in classification. The study area is a part of Dunhuang, Gansu Province, China. An L-band full-polarization image of Dunhuang which includes quad-polarization modes was acquired by the ALOS-PALSAR(Advanced Land Observing Satellite–the Phased Array type L-band Synthetic Aperture Radar). Firstly, new characteristic information was extracted by the difference operation, ratio operation, and principal component transform based on the full-polarization(HH, HV or VH, VV) modes SAR data. Then the single-, dual-, full-polarization SAR data and new SAR characteristic information were used to analyze quantitatively the classification accuracy based on the Support Vector Machines(SVM). The results show that classification overall accuracy of single-polarization SAR data is poor, and the highest is 56.53% of VV polarization. The classification overall accuracy of dual-polarization SAR is much better than single-polarization, the highest is 74.77% of HV VV polarization data. The classification overall accuracy of full-polarization SAR is 80.21%, adding the difference characteristic information, ratio characteristic information and the first principal component(PC1) respectively, the overall accuracy increased by 3.09%, 3.38%, 4.14% respectively. When the full-polarization SAR data in combination with the all characteristic information, the classification overall accuracy reached to 91.01%. The full-polarization SAR data in combination with the band math characteristic information or the PC1 can greatly improve classification accuracy.     

Boolean matrix operators for computing binary topological relations between complex regions

Complex regions are composed of a finite number of simple regions, and are always defined by hierarchical representation methods. This article focuses on a unified method for computing n-intersection-based binary topological relations between complex regions based on hierarchical characteristics, using known topological relations between simple regions. The hierarchical representation of complex regions is defined as the recursive process of region decomposition using a context-free grammar. To distinguish multiple components of a region and whether the interior of a hole is a part of the inner exterior or the outer exterior, three region operators are proposed to describe the configuration of a region represented as a formal expression. Then, three corresponding 25-intersection (25I) based Boolean matrix operators are proposed to compute topological relations based on the relationships between decomposed regions. Herein, the invalid conditions of the operators are verified in detail, and the invalidities can be eliminated by either applying our definition of complex regions or with the inclusion of additional information. The proposed 25I-based operators, as shown in our cases, can be used as a ‘bridge’ to link different n-intersection models, and as a useful computation tool for analyzing topological relations between regions with specific configurations.     

临哈铁路典型防沙工程区阻风效率与积沙量特征

为掌握临哈铁路沿线风沙防护措施的防护效果,优化布设方案,选择临哈铁路K217、K585、K745及其支线天策线K16典型防沙工程区,采用样带同步观测法和测钎法,测定了每个区域的阻风效率和积沙量特征.结果表明:由铁路外侧向内侧,防沙工程对风的抑制效应逐渐增强.1.5 m高沙障积沙带、2.5 m深路堑、10 m和16 m高...     

沙障对流沙地植被和土壤养分的影响

机械沙障是风沙防治的重要工程措施。以设置在腾格里沙漠东南缘的沙坡头和吊坡梁不同年份的高密度聚乙烯(HDPE)沙障和麦草沙障为研究对象,分析沙障对植被生长和土壤养分的影响。结果表明:2012年和2010年布设的HDPE沙障中植被的物种数大于同期草方格沙障中的物种数;两种沙障内植被的物种多样性指数较低,且随沙障布设时间增加而增高,同期布设的HDPE沙障比草方格沙障的多样性指数高。沙障使土壤pH值总体呈降低的趋势,草方格沙障内的土壤pH值低于HDPE沙障内的土壤pH值;沙障内表层土壤(0~5 cm)的全氮、有机碳、速效钾、速效磷含量高于裸沙表层,呈增加的趋势,两种沙障间的表层土壤养分含量差异不显著。     

长沙市城市居民宅基地转入意愿及影响因素

研究宅基地转入方的需求意愿及影响因素可为构建科学合理的宅基地流转制度提供参考。从需求的角度出发,构建城市居民宅基地转入意愿影响因素分析模型,以长沙市为例,运用Logistic回归模型分析了城市居民宅基地转入意愿的影响因素。结果表明:影响城市居民宅基地转入意愿的因素主要有宅基地形状、城市居民年龄、城市居民家庭住房使用年限、宅基地产权、宅基地与中心城区的距离和宅基地基础设施状况。宅基地流转应以城中村和城郊村为试点范围,加快宅基地确权颁证,完善宅基地基础设施。     

Development of land use transitions research in China

With the introduction of the concept of land use transition into China, related researches have been carried out extensively in the past two decades, which enrich the knowledge of land system science. This paper describes the development of research on land use transitions in China from the perspectives of conceptual connotations, theoretical model, research methods, and research progress and prospects. With the in-depth investigation of land use transitions, the concept and connotations of land use morphology are developed and encapsulated as two kinds, i.e., dominant morphology and recessive morphology. The dominant morphology refers to the land use structure of a certain region over a certain period of time, with features such as the quantity and spatial pattern of land use types. While the recessive morphology includes the land use features in the aspects of quality, property rights, management mode, input, output and function. Accordingly, the concept of land use transition is further developed, and the theoretical model of regional land use transitions is established. Thereafter, three innovative integrated approaches to study land use transitions are put forward, i.e., multidisciplinary research framework for recessive land use transition, transect and horizontal comparison. To date, there have been 62 Ph.D. and 166 M.S. dissertations on the topic of "land use transition" in China. During 2002–2019, the National Natural Science Foundation of China has funded 48 research programs on the theme of "land use transition". As such, the Chinese scholars have adapted the concept derived from western literature to the situations and experiences in China.     

珠海荷包岛植被资源及其开发利用

本文在多次实地调查基础上，对珠海荷包岛的自然环境条件、植被类型和资源植物等作了较详细的阐述，并根据本岛旅游资源丰富，自然林面积在等特性，提出建立海岛森林公园，达到保护和发展植被资源的目的。     

Screening of cellulose decomposing fungi in sandy dune soil of Horqin Sandy Land

Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and four efficient cellulose decomposing fungi (NM3-1, NM3-2, NM3-3, and NM3-4) were screened using a CMC (carboxymethyl cellulose) carbon source in dune soil of Horqin Sandy Land. They were identified as Asperigillus calidoustus, Fusarium oxysporum, Fusarium solani, and Hypocrea lixii by rDNA-ITS molecular biological methods. Cloth decomposition rates were 15.71%, 15.89%, 17.29%, and 17.89% by the four efficient decomposers incubated for 30 days, respectively. Screening of efficient cellulose decomposers can not only increase the dune soil functional microbe bank, but can also accelerate litter decomposition and available nutrient input in the Horqin Sandy Land.     

金衢盆地加积红土多指标记录的环境变化

金衢盆地连片、集中分布有较厚的第四纪古红土。选择汤溪(TX)加积型红土剖面进行了磁学、色度和粒度的测量,研究结果表明:1)剖面上段的表土层和均质红土层磁化率高,磁性矿物以亚铁磁性矿物为主;剖面中段的网纹红土层磁化率低,磁性矿物以不完整反铁磁性矿物(如赤铁矿)含量为主;剖面底部的黄色网纹化砾石层磁化率低,磁性矿物以不完整反铁磁性矿物为主。2)色度指标值(a*、b*、L*)偏高说明东部季风区湿热的气候条件,不同层位的差异说明不同层位具有不同的成土环境。3)粒度组成显示有一定的风成沉积特征,比较一致,以粉砂为主,但不同土壤层之间存在差异。剖面底部黄色网纹化砾石层可能为干冷的早期河流沉积环境;中部网纹红土层反映的是暖湿多水而且干湿交替变化频繁的沉积环境;上部均质红土层则反映了与现代区域气候相似的沉积环境。