中国主要沿海城市旅游竞争力定量研究     

钟敬秋  李悦铮  江海旭  吕俊芳 《世界地理研究》2013,(3):136-144

基②国内外对城市旅游竞争力研究的回顾和梳理,建立契合本研究的指标体系：以城市旅游基础设施、发展现状和生态环境竞争力作为二级指标,以25个与城市旅游竞争力相关指标作为三级指标。在此基础上,利用主成分分析与系统聚类分析方法测算各城市因子得分及排名,并对城市间、等级间、区域间优势和劣势做出比较分析。结果表明：①上海、杭州、广州旅游竞争力相对较强,南通、中山、东莞竞争力相对较弱,其中,城市经济体规模、环境污染程度及城市绿化水平对城市旅游综合竞争力影响较突出;②城市间旅游竞争力水平梯度化明显,抱团式合作发展、阶梯状搭配发展前景看好;③同一区域内城市合作优势大②竞争优势,可建立旅游合作试点区域。  相似文献   

Regional dynamics of terrestrial vegetation productivity and climate feedbacks for territory of Ukraine     

Dmytro Movchan  Yuriy V. Kostyuchenko 《International journal of geographical information science》2013,27(8):1490-1505

Climate change has the potential to affect terrestrial ecosystems and, thereby, the carbon cycle. Various vegetation biomes are likely to respond differently to changes in climatic factors. The purpose of this study was to analyse the trends of the terrestrial vegetation productivity and climate drivers on regional levels and relations between ones. The gross primary productivity from the global satellite-based terrestrial production efficiency model (PEM) MOD17 as the vegetation productivity indicator and meteorological data from the weather station network as climatic indicators were used. The analysis covered a period from 2000 to 2012. Correlation analysis was used to quantify the association between the vegetation productivity and climatic indicators for different growing seasons and landscape-climatic zones of Ukraine. The Mann–Kendall trend test was applied to take into account seasonal features. Multiple linear regression models for corresponding seasons and zones have been simulated using the principal component analysis. The results showed no detectable limiting effect of the climatic drivers on plant productivity for forest areas. The limiting effect of the temperature increasing and precipitation amount decreasing for the steppe zone and eastern forest-steppe subzone of Ukraine for summer was observed.  相似文献   

A World Model of Chemical Denudation in Karst Terrains     

《The Professional geographer》2013,65(3):397-406

In this paper, I develop global karst chemical denudation models using chemical equilibrium equations. Theoretical karst chemical denudation rates are calculated as soil carbon dioxide concentration varies from 10^?3.5 atm to 10^?1.0 atm, temperature varies from 0°C to 30°C, and annual runoff varies from 500 mm to 3,000 mm. Both open and closed karst solution systems are examined. The Drake (1980) and the Brook-Folkoff-Box (1983) soil pCO² equations are used to develop chemical denudation models for different carbonate rocks (limestone and dolomite), climate (tropical, temperate, and arctic/alpine terrains), and karst solution type (open and closed systems). The major conclusion is that the karst solution type, least known in the past karst studies, is an important factor in controlling chemical denudation rates.  相似文献   

基于主成分分析的BP神经网络模型的形变预测方法          下载免费PDF全文

陈春花  陈兴权  朱超 《海洋测绘》2010,30(1):47-49

主成分分析可以提取形变主要信息，BP神经网络具有很强的预测功能，提出将两者相结合用于形变监测数据处理。通过MATLAB编程实现了该算法，并用实测数据进行验证，证明此方法能够提高预测数据的精度和可靠性。结果表明：与其他方法相比，基于主成分分析的改进BP神经网络能取得更好的预测效果。  相似文献   

Serial dependence properties in multivariate streamflow simulation with independent decomposition analysis     

Taesam Lee 《水文研究》2012,26(7):961-972

Stochastic simulation of multivariate hydrologic variables has a key role in evaluating alternative designs and operation rules of hydrologic facilities. The recently developed decomposition analysis, Independent Component Analysis (ICA), allows us to apply the simple univariate time series model to each extracted component by: (1) decomposing multivariate time series into independent components with ICA; (2) modelling and generating each component independently; and (3) mixing the generated components to come back to observational domain. However, we illustrate in the current study that fitting a univariate time series model to each extracted component might end up with the underestimation of the serial dependence that the observation data might contain. A alternative for parameter estimation is suggested to preserve the serial dependence of the observation variable using the relationship between the observation variable and the decomposed variable. The case study of the Upper Colorado River basin shows that some improvement is made through the suggested alternative. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

夏季南黄海海水化学要素的分布特征及影响因素   总被引：8，自引：0，他引：8  

韦钦胜  刘璐  战闰  魏修华  臧家业 《中国海洋大学学报(自然科学版)》2010,40(1)

基于2006年7月对南黄海调查所得资料,对南黄海海水化学要素的分布特征及影响因素进行了探讨.结果表明:(1) 调查海域底层122°E～123°E,33°N以南范围内存在明显的DO亏损现象,证实了长江口外低氧区向南黄海的扩展态势.(2) 南黄海西南部上层水体中的营养盐主要来源于长江冲淡水及苏北沿岸流的输运,且营养盐与盐度之间呈较好的负相关,具有一定的保守性,同时发现表层无机氮盈余状况的分布与该海域环流的扩展途径密切相关;南黄海西南部底层东北向的高营养盐水舌是长江冲淡水、台湾暖流前缘水以及底层有机物分解释放营养盐综合作用的结果;南黄海冷水域因有机物分解而积聚了大量营养盐.(3) 根据南黄海冷水域海水化学要素的断面分布,指出自DO最大值层开始产生至观测之时该层之下、真光层以内光合作用产氧在温跃层下界的积累和保存在氧最大值形成过程中具有极其重要的作用.  相似文献   

SZ36-1油田污水悬浮物无机组分研究     

李旭  唐洪明  刘义刚  高建崇  刘璐 《海洋地质译丛》2010,(2):53-57,71

综合利用扫描电镜能谱分析、X-射线衍射仪等先进仪器对SZ36-1油田滤膜组分燃烧前后进行综合分析研究。通过分析无机组分中Fe、Ca等元素的变化规律,并结合现场水质监测数据,研究发现SZ36-1油田回注污水由CEP向AJ、平台输送过程中水质逐级恶化;同时污水由CEP到A平台再到J平台过程中,Fe原子百分比平均值依次为4.45%、13.03%、19.45%,Ca原子百分比平均值依次为4.33%、5.43%、5.66%。腐蚀、结垢现象逐渐加剧,是导致注水水质恶化的主要原因。  相似文献   

基于MODIS的2006-2016年西藏生态质量综合评价及其时空变化   总被引：2，自引：0，他引：2  

吴宜进  赵行双  奚悦  刘慧  李畅 《地理学报》2019,74(7):1438-1449

针对缺少基于遥感数据产品的西藏地区植被生态参数筛选及综合评价的研究现状,以2006年和2016年西藏地区MODIS卫星遥感产品反演得到的植被覆盖度、叶面积指数、植被总初级生产力、区域热度与改进的湿度5项指标为基础,提出了基于主成分分析法的西藏植被生态环境质量评价方法,并探索了其时空变化规律及机理。结果表明：① 西藏地区植被生态质量整体较为脆弱,且区域差异明显,呈现东南优、西北差的分布格局。② 2006-2016年间西藏地区植被生态质量总体呈现变好的趋势。在时间序列上,2006-2016年间改善、退化的区域占比分别为31.88%和4.13%;在空间分布上,变好的区域分布在西北、中部和东部,变差的区域集中在东南部。③ 水热状况改善特别是降水量的增加和人为保护政策使得研究区西部和中部地区生态质量有所提高。社会经济活动加强是研究区东南部生态质量变差的主要原因。  相似文献   

美洲黑石斑鱼含肉率及肌肉营养成分分析   总被引：9，自引：0，他引：9  

党冉  竺俊全  邱新志 《海洋学研究》2010,28(2):60-66

利用常规肌肉营养测试方法,测定分析了美洲黑石斑鱼的含肉率及肌肉营养成分。测定结果显示,美洲黑石斑鱼含肉率平均值为(73.71±1.93)%,肌肉(鲜样)中粗蛋白、粗脂肪、水分和粗灰分含量分别为(19.09±1.34)%,(6.14±1.76)%,(71.86±1.58)%和(1.32±0.17)%;美洲黑石斑鱼肌肉中被测出的常见氨基酸(色氨酸未测定)有17种,其中包括7种必需氨基酸、2种半必需氨基酸和8种非必需氨基酸,其氨基酸含量占鲜体质量的百分比分别为(8.27±0.21)%,(1.84±0.08)%和(10.15±0.31)%,17种氨基酸总含量为(20.26±1.13)%(鲜样)。谷氨酸(Glu)含量占鲜体质量的百分比最高,为(3.27±0.16)%,其次是天冬氨酸(Asp)和赖氨酸(Lys),胱氨酸(Cys)含量占鲜体质量的百分比为最低,仅为(0.27±0.01)%。4种鲜味氨基酸含量占干样的(29.32±0.14)%。鲜样的美洲黑石斑鱼必需氨基酸总量占氨基酸总量的比值为40.82%,干样的为40.81%;鲜样的必需氨基酸总量与非必需氨基酸总量的比值为81.48%,干样的为81.43%,其构成符合FAO/WHO的标准。同时计算出的美洲黑石斑鱼肌肉蛋白质氨基酸评分(AAS)均大于1,化学评分(CS)均大于0.7,必需氨基酸指数(EAAI)达到91.18,高于多数海产经济鱼类,说明它能为人体提供大量必需氨基酸,且其组成接近人体的氨基酸需要量模式。美洲黑石斑鱼肌肉中主要含有16种脂肪酸,其中饱和脂肪酸(SFA)7种,含量占肌肉脂肪酸总量的(38.66±1.22)%;不饱和脂肪酸(UFA)9种,含量占肌肉脂肪酸总量的(61.36±0.98)%,其中单不饱和脂肪酸(MUFA)5种,多不饱和脂肪酸(PUFA)4种。多不饱和脂肪酸中的人和动物生长发育必需的脂肪酸EPA和DHA含量,分别占总脂肪酸的(9.02±0.59)%和(11.73±0.43)%。-ω3族与-ω6族PUFA总量的比值为5.30。分析表明,美洲黑石斑鱼肌肉含肉率高,含有较多的粗蛋白和粗脂肪,氨基酸总量及鲜味氨基酸含量均较高,是一种优质蛋白源;美洲黑石斑鱼肌肉富含PUFA,尤其是EPA和DHA含量丰富,并且∑n3/∑n6值较高,因而具有较高的食用营养价值和保健功效,是一种具有广阔市场前景的优良养殖品种。  相似文献   

Growth of plagioclase rims around metastable kyanite during decompression of high‐pressure felsic granulites (Bohemian Massif)     

R. ABART  G. NEUSSER  D. RHEDE 《Journal of Metamorphic Geology》2011,29(9):1003-1018

Samples of high‐pressure felsic granulites from the Bohemian Massif (Variscan belt of Central Europe) characterized by a peak metamorphic (high‐pressure) mineral assemblage of garnet – kyanite – plagioclase – K‐feldspar – quartz ± biotite show well‐developed plagioclase reaction rims around kyanite grains in two microstructural settings. In one setting, kyanite is randomly distributed in the polyphase matrix, whereas in the other setting, it is enclosed within large perthitic K‐feldspar. Kyanite is regarded as a relict of the high‐pressure metamorphic assemblage that became metastable during transition to a low‐pressure overprint. Plagioclase rims from both microstructural settings show continuous outwards decrease of the anorthite content from An_32–25 at the contact with kyanite to An_20–19 at the contact with the matrix or to the perthitic K‐feldspar respectively. Based on mass balance considerations, it is shown that in some cases, a small amount of kyanite was consumed in the rim‐forming reaction to provide the Al₂O₃ component for the growth of plagioclase, whereas in other cases no Al₂O₃ from kyanite was necessary. In a majority of examples, the necessary Al₂O₃ was supplied with CaO and Na₂O from the surrounding matrix material. For kyanite in perthite, a thermodynamic analysis reveals that the kyanite became metastable at the interface with the host perthite at the peak metamorphic pressure, and therefore the plagioclase rim started to grow at ～ 18 kbar. In contrast, kyanite in the polyphase matrix remained stable down to pressures of ～ 16 kbar, and the plagioclase rim only started to grow at a later stage during the decompression. Plagioclase rims around kyanite inclusions within large perthite have a radial thickness of up to 50 μm. In contrast, the radial thickness of plagioclase rims around kyanite in the polycrystalline matrix is significantly larger, up to 200 μm. Another peculiarity is that the plagioclase rims around kyanite in the matrix are polycrystalline, whereas the plagioclase rims around kyanite inclusions in perthitic hosts are single crystals with the same crystallographic orientation as the host perthite. The difference in rim thickness for the two microstructural settings is ascribed to the differences in the efficiency of chemical mass transfer next to the reaction site. The comparatively large thickness of the plagioclase rims grown around kyanite in the matrix is probably due to efficient material transport along the grain and phase boundaries in the matrix. In contrast, chemical mass transfer was comparatively slow in the large perthitic K‐feldspar grains.  相似文献