历史文化名城名胜组景的时空演变特征研究——以金陵四十八景为例     

苏醒  张捷  张宏磊  钟士恩  陈星  李宜聪  李茹 《地域研究与开发》2014,(5)

名胜组景是一定地域范围内景观的组合,是历史文化名城的重要城市地标和旅游资源。以南京的金陵四十八景为例,研究名胜组景的时空演变特征。研究发现:金陵古代名胜组景依赖于自然地理环境,密集分布在长江、钟山、秦淮河等山脉和河流附近,同时也受人文地理界线的影响,较集中于南京城墙内;民国至当代的金陵四十八景的空间分布呈现东进南延北拓态势,逐步扩散至人文地理边界以外的外城郭,进而扩散到郊区县市(江北、高淳、溧水)。名胜组景的这种时空变迁特征与城市变迁存在强烈的关联。历史文化名城的组景景观可划分为自然景观和人文景观。金陵四十八景的时间演进过程中呈现自然景观数量减少、人文景观数量增多的趋势,景观景名、排序等存在较大的差异。古今游憩偏好的变化、旅游需求的变化、历史文化景观的积累、宗教变革、土地利用、社会职能的转变、时代文化的差异都对此产生一定程度的影响。  相似文献   

The use of GIS tools to support decision-making in the expansion of chain stores     

Rafael Suárez-Vega  Dolores R. Santos-Peñate 《International journal of geographical information science》2014,28(3):553-569

This article deals with a network competitive localization problem in which a firm seeks to determine the location of a new facility, which competes with all the facilities operating in the market, both belonging to the same firm and to the competing firms. In this context, two frequently conflicting objectives are involved: maximization of the total market share captured by the firm and minimization of market share losses for its existing facilities due to being captured by the new facility (cannibalization). We formulate the location problem as a multi-objective optimization model. Some GIS tools that provide some maps representing the market share and the cannibalization effect are proposed. This allows for the visualization of the effects produced by the opening of a new facility in the market and the trade-offs between the objectives. Finally, the advantages of using these tools have been shown by means of an application to a real data case.  相似文献   

Effects of fertilization on population density and productivity of herbaceous plants in desert steppe     

JieQiong Su  XinRong Li  HaoTian Yang 《寒旱区科学》2014,6(3):0219-0225

In order to investigate the impacts of fertilization on population density and productivity on herbaceous plants in desert steppe, nitrogen （N）, phosphorus （P）, and N-P addition experiments were performed. Each fertilizer treatment included four addition levels, i.e., 0, 5, 10, and 20 g/m2. The results indicated that population density decreased as fertilization levels increased regardless of the sort of fertilizer. More specifically, total density as well as density ofArtemisia capillaris, Allium polyrhizum, and Enneapogon brachystachyus decreased significantly in 20 g/m2 treated plots, as compared with the control plots. Fertilization effects on aboveground and root biomasses were extremely similar to that found in population density; that is, both total aboveground biomass and aboveground biomasses for A. capillaris, A. polyrhizum, and E. brachystachyus were negatively correlated with increasing fertilization levels, with all determination coefficients （R2） greater than 0.80. Therefore, in the case of desert regions （annual precipitation 〈180 mm）, fertilization would inhibit population density and productivity of herbaceous plants.  相似文献   

An improved method for correction of air temperature measured using different radiation shields     

Xinghong Cheng  Debin Su  Deping Li  Lu Chen  Wenjing Xu  Meilin Yang  Yongcheng Li  Zhizhong Yue  Zijing Wang 《大气科学进展》2014,31(6):1460-1468

The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was studied.Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012.Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers （FRP） Stevenson screen.In most cases,the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield.The measured errors changed sharply at sunrise and sunset,and reached maxima at noon.Their diurnal variation characteristics were,naturally,related to changes in solar radiation.The relationships between the record errors,global radiation,and wind speed were nonlinear.An improved correction method was proposed based on the approach described by Nakamura and Mahrt （2005） （NM05）,in which the impact of the solar zenith angle （SZA） on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively.Measurement errors were reduced significantly after correction by either method for both shields.The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3％ and 40.4％ higher than those using the NM05 method,respectively.  相似文献   

Effects of rice straw on the cell viability,photosynthesis, and growth of Microcystis aeruginosa     

苏文  贾育红  卢亚萍  孔繁翔 《中国海洋湖沼学报》2014,32(1):120-129

Rice straw is supposed to be an environment-friendly biomaterial for inhibiting the growth of harmful blooms of the cyanobacterium Microcystis aeruginosa. However, its potential mechanism is not well known. To explore this mechanism, the growth, cell viability （esterase activity, membrane potential, and membrane integrity）, photosynthesis, and cell size ofM. aeruginosa were determined using flow cytometry and Phyto-PAM after exposure to rice straw extracts （RSE）. The results show that doses from 2.0 to 10.0 g/L of RSE efficiently inhibited the alga for 15 days, while the physiologic and morphologic responses of the cyanobacteria were time-dependent. RSE interfered with the cell membrane potential, cell size, and in vivo chlorophyll-a fluorescence on the first day. After 7 days of exposure, RSE was transported into the cytosol, which disrupted enzyme activity and photosynthesis. The cyanobacteria then started to repair its physiology （enzyme activity, photosynthesis） and remained viable, suggesting that rice straw act as an algistatic agent.  相似文献   

World cities and international organizations: Political global-city status of Chinese cities   总被引：3，自引：1，他引：2  

Nian Su  Desheng Xue  John Agnew 《中国地理科学(英文版)》2014,24(3):362-374

In this study, the authors use a political perspective to explore the relative global status of cities in China. Two questions are addressed. Firstly, by using international organizations as the subjects and quantitative analysis of the spatial distribution of their offices, the overall position of Chinese cities in the global distribution of international organizations is estimated. The results show that 22 Chi- nese cities are involved in international political affairs. Beijing, Shanghai and Guangzhou dominate these activities and have high po- litical global-city status. Secondly, through qualitative analysis of Guangzhou City, the authors explore how its status as a center for intemational organizations has been shaped in recent years. The locational decision-making process is analyzed and the factors are demonstrated at both national and city scales. The definition of international organizations as used in this study refers not only to those supranational bodies that have the ability to manage relations across states （such as the European Union）, but also those in- ter-governmental organizations （IGOs）, international non-governmental organizations （INGOs） and diplomatic representatives and delegations that today also manage and regulate relations between and among states.  相似文献   

内蒙古航空气象预报服务业务系统     

苏立娟  达布希拉图  毕力格  史金丽  郑旭程  邢启明 《内蒙古气象》2014,(2):36-39

利用数值预报技术开发了包括背景资料自动采集传输、航空气象业务产品预报模块、产品后处理、产品的采集传输和内蒙古航空气象服务网站五个部分的内蒙古自治区航空气象预报服务业务系统。通过业务系统的开发达到给内蒙古气象部门内部承担航空气象服务的民航气象台提供技术指导和预报指导产品,提升为航空气象预报服务的能力和科技水平。  相似文献   

气溶胶光学厚度谱特征判断粒子大小方法初探   总被引：4，自引：0，他引：4       下载免费PDF全文

杨溯  石广玉  王标  杨红龙  赵剑琦  秦世广 《应用气象学报》2011,22(2):152-157

当气溶胶谱满足Junge分布时,Angstrom指数 (α) 可以准确地描述粒子大小,但真实大气气溶胶很少完全满足这一条件,仅用α判断粒子大小会有较大出入。基于北京、香河、兴隆、太湖4个Aeronet观测站21世纪以来各站历时都超过1年的气溶胶光学厚度资料,获得5511组lnτ与lnλ的二次拟合参数a₂,a₁,尝试找到一种结合α,a₂,a₁判断粒子大小的方法。结果表明:当气溶胶为粗粒子时 (V_fine/V_total＜0.2),α均小于0.75,仅用α就可以较好地判断粒子大小,但当气溶胶以细粒子为主时 (V_fine/V_total＞0.7),该方法会有较大出入,此时a₂,a₁可以有效地辅助α判断粒子大小,α＞0.75,a₂＜-0.5或a₂＜-0.5,a₁＜-1.0是较好的判据。此外,分析发现国外研究提出的用a₂-a₁判断粒子大小的方法效果并不理想,尤其在1＜a₂-a₁＜2的情况下,粒子的组成有多种可能。  相似文献   

典型南涝（旱）北旱（涝）梅雨大气环流特征差异及动力诊断分析   总被引：5，自引：1，他引：4  

牛若芸  苏爱芳  马杰 《大气科学》2011,35(1):95-104

利用NCEP逐日再分析资料,采用合成分析和动力诊断方法比较研究了典型南涝(旱)北旱(涝)梅雨大气环流特征差异,逐一考察了近20种物理量对其主雨带位置的诊断识别能力.结果表明:典型南涝(旱)北旱(涝)梅雨极涡偏强(弱),亚欧中高纬槽脊振幅较大(小),中纬度110°E～150°E地区位势高度明显偏低(高),冷空气势力偏强(...  相似文献   

Plant growth and the performance of mangrove wetland microcosms for mariculture effluent depuration     

Su YM  Lin YF  Jing SR  Hou PC 《Marine pollution bulletin》2011,62(7):1455-1463

This study established wetland microcosms that were either unplanted or planted in monoculture with native mangrove species in Taiwan (Avicennia marina, Rhizophora stylosa, and Lumnitzera racemosa) for the purpose of receiving high-salinity mariculture effluents; additionally, the microcosms operated at different hydraulic retention times (HRTs). Plant growth and the performance of the microcosms with respect to pollutant removal were investigated. The results showed that seedlings of all three mangrove species survived and grew sufficiently well under continuous flooding. The presence of mangroves consistently improved SS, BOD₅, and TP removal, particularly under short HRT conditions. The mangrove microcosms removed pollutants from the mariculture effluents with efficiencies of 5.7-27.1% (SS), 4.9-36.3% (BOD₅), 18.7-29.9% (TP), 21.2-49.8% (NH₄-N), and 5.4-37.7% (NO_x-N). A. marina and L. racemosa were more tolerant of continuous flooding than R. stylosa. However, no species displayed consistently superior performance in decreasing all pollutant-related parameters investigated. For all pollutants, microcosms operating at a 2-d HRT exhibited a higher removal efficiency than those operating at a 0.5-d HRT.  相似文献