共查询到20条相似文献，搜索用时 31 毫秒
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Fei Hongping 《地理学报(英文版)》1994,(Z1)
I.MdjorAI)I)roacI1esThege0graPhyofenterprise,nane1ycorpOrategeograPhy,isabranchofecon0micgeographywhichdiscussesthespatialbehaviourofbusinesscooprationswithspecia1emphasis0nfirm-environl11e11ti11terdependc11cics,andare1ative1yl1e\vmicro-1evelanalytica1approachinecol1ol11icssu9up11}'.:f`col1.ldcl'ablel1ul1lbcI0rstudieswhichin0neWayoranotherincorporated"enterprise"asadimensioninindustrialandregi0nalec0nomicanalysisareintegra1tocontemp0raryempiric31industl-iallocati0l1researcll.Tl1el110sttypi… 相似文献
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马蹄黄(Spenceria ramalana)是滇西北亚高山草甸的旅游景观资源,其地上形态特征随草甸退化梯度的变化趋势尚少见报道。于2018年7月在香格里拉市调查、对比了3个退化梯度(一级退化,DI;二级退化,DII;无退化对照,CK)上马蹄黄的植株高度、展度、叶片数量、叶片长度、叶片宽度、叶面积、叶片长宽比和生存状态。结果表明:(1)与CK相比,DI和DII梯度上马蹄黄的植株高度、展度、叶片数量、叶片长度、叶片宽度和叶面积均显著减小(P<0.05);(2)DII梯度上马蹄黄的叶片长度、叶片宽度和叶面积显著高于DI梯度(P<0.05);(3)CK、DI和DII中马蹄黄的叶片长宽比分别为3.5±0.3、2.9±0.4和2.3±0.1,叶片形状由倒披针形向倒卵形过渡;(4)DI、DII和CK中马蹄黄的生存状态指数分别是0.12、0.23和0.63。 相似文献
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《The Professional geographer》2013,65(4):389-392
The Thornthwaite method for computing evapotranspiration has been employed in a variety of climatic realms. Recently, the equation for computing potential evapotranspiration has been shown to underestimate measured moisture losses in dry environments. This study presents monthly calibration equations that enhance the reliability of the Thornthwaite estimates of evapotranspiration for California stations. Six years of calibrated monthly potential evapotranspiration are compared with lysimetermeasured evapotranspiration at Davis and with other estimates of evapotranspiration for this site. 相似文献
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Eeing located in a region of mountains and not far from coast in low latitudes,Kwarngsi is one of the regions of maximum rain all in China. Among the types of rainfal, orographic type is the most important. That is what the rainfall maps 相似文献
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L.C.Li 《地理学报(英文版)》1935,(4)
Eeing located in a region of mountains and not far from coast in low latitudes,Kwarngsi is one of the regions of maximum rain all in China. Among the types of rainfal, orographic type is the most important. That is what the rainfall maps 相似文献
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中国的低碳旅游研究尚处于起步阶段,将现有研究成果进行总结与分析,是推进研究进展不可回避的环节。通过对中国低碳旅游研究文献的全面搜集,阐述了低碳旅游概念、低碳旅游与旅游业、低碳旅游与政府3个研究领域的主要研究进展,同时对各种发展低碳旅游的措施建议进行分析比较。在此基础上,认为中国低碳旅游研究在不断广泛化、深度化的同时,仍存在介绍性、定性、理论性阶段,且存在同一研究领域结论相重叠的问题,今后应进一步重视低碳旅游的定量研究,同时注重多学科综合应用。 相似文献
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The effect of distance upon agricultural production should be as apparent among primitive subsistence agriculturalists as in market-oriented societies. This analysis of yield variations among the Basotho of southern Africa attempts to determine the frictional effect of distance. The results show that distance does not explain variations in yield even when other physical factors are held constant. Perhaps such variables as household characteristics, not included in the analysis, would provide a better explanation. 相似文献
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湖南省郴州市在经济发展中具备资源丰富，邻近发达的珠江三角洲地区，区位优势等众多有利条件，但同时也存在区内交通不便，经济基础薄弱等一些不利因素。为抓住所面临的大好机遇，作者提出了加快该区基础设施建设、软环境建设、重视科技、加强环境保护和发展旅游等5项对策，并提出了该区经济发展可持续模式；即产业结构优化模式和点轴开发空间布局，最后提出了进一步完善布局的建议。 相似文献
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A detailed study has been made of the remanent magnetization of five Pilansberg dykes, by means of measurements on oriented specimens of the rocks. Outcrops of the dykes prove to have suffered magnetic disturbance of their original thermo-remanent magnetization. Specimens from depths of a few thousand feet, taken in Witwatersrand gold mines, show highly consistent magnetisation of the basic parts of the dykes over considerable distances between sampling sites. The mean directions given by the five dykes agree well, and the mean direction from the five dykes gives a North-seeking magnetic pole with inclination +69.3 and azimuth N 24° E. Assuming thermo-remanent magnetisation by a geocentric dipole field, this places a North magnetic pole in latitude 71/2° N, longitude 421/ E at the time of intrusion of the dykes. The age of the dykes is uncertain, but is probably about 300 to 400 million years. Some of the specimens have been subjected to alternating magnetic fields in order to test the stability of their magnetisations. The basic specimens are found to be highly stable, being only slightly affected by fields of 100 to 300 oersteds. The possible implications of the results are discussed, in terms of hypotheses of polar wandering and continental drift. 相似文献
A detailed study has been made of the remanent magnetization of five Pilansberg dykes, by means of measurements on oriented specimens of the rocks. Outcrops of the dykes prove to have suffered magnetic disturbance of their original thermo-remanent magnetization. Specimens from depths of a few thousand feet, taken in Witwatersrand gold mines, show highly consistent magnetisation of the basic parts of the dykes over considerable distances between sampling sites. The mean directions given by the five dykes agree well, and the mean direction from the five dykes gives a North-seeking magnetic pole with inclination +69.3 and azimuth N 24° E. Assuming thermo-remanent magnetisation by a geocentric dipole field, this places a North magnetic pole in latitude 71/2° N, longitude 421/ E at the time of intrusion of the dykes. The age of the dykes is uncertain, but is probably about 300 to 400 million years. Some of the specimens have been subjected to alternating magnetic fields in order to test the stability of their magnetisations. The basic specimens are found to be highly stable, being only slightly affected by fields of 100 to 300 oersteds. The possible implications of the results are discussed, in terms of hypotheses of polar wandering and continental drift. 相似文献
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JOHNH.KALIVAS 《地理学报(英文版)》1989,(1)
Care is required for multicomponent analysis if misleading results are to be avoided. The problem ofill-conditioned calibration matrices is of primary concern. This type of numerical instability isrepresented as spectral overlap of calibration spectra. Depending on the degree of spectral overlap, thesample concentration estimates can be severely affected. A practical statistical procedure is discussedwhich tests for the presence of spectral overlap among the pure-component spectra and simultaneouslyassesses the degree that concentration estimates may be degraded. Guidelines are developed to ascertainhow much departure from spectral orthogonality is acceptable. 相似文献
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资源型城市的可持续发展优化及案例研究 总被引：11，自引：1，他引：10
郑伯红 《云南地理环境研究》1999,11(1):51-56
资源型城市是伴随着资源开发而兴起的, 其发展前景受资源条件和社会经济的双重制约。通过分析资源型城市生命周期阶段的特征和问题, 提出了其可持续发展优化的方向为： 延长资源开发利用周期, 避免城市过早步入衰退期; 调整城市发展规划, 改变城市生命趋向; 同时进行行政区域调整, 转变城市职能。最后, 以湖南省冷水江市为例, 进行了实证分析。 相似文献