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81.
战略耦合的研究脉络与问题 总被引:5,自引:9,他引:5
在回顾经济地理学中较为前沿的战略耦合概念的起源、发展与研究现状的基础上,对战略耦合研究的优点与问题展开评述,认为当前研究在战略耦合模式的探讨中,主要基于经验总结而缺乏对影响变量,特别是空间变量的阐述,存在一定的模糊性。为理解该问题的根源,追溯了全球生产网络和全球价值链两个学派的争论和最新进展。在认可全球价值链理论解释力的同时,认为当前全球生产网络2.0版本的研究框架仍然没有解决模糊性的问题,而且全球生产网络的分析框架主要侧重于主导企业视角来构建战略耦合的发生机制,忽略了后发地区和企业的主动性。因此,借鉴传统经济地理学研究,充分考虑主导企业和后发地区的行为逻辑,提出经济活动的空间粘性和区域的区位优势这两个变量,重构了战略耦合的分析框架,并进行理论阐述。该项理论构建有助于更好地厘清战略耦合的发生机制,帮助发展中国家和地区判读发展机遇,确立产业发展与升级战略。 相似文献
82.
乌兰布和沙漠东北缘地表风沙流结构特征 总被引:9,自引:4,他引:9
在国家林业局磴口荒漠生态站长期监测的基础上,利用多种积沙仪,对乌兰布和沙漠东北缘流动沙丘、油蒿半固定沙丘、白刺半固定沙丘、油蒿固定沙丘、白刺固定沙丘5种典型下垫面近地面(0~100 cm)的风沙流输沙量进行了实地观测和对比分析。结果表明:(1) 输沙率(q)随高度(h)增加呈幂函数(q=ah-b,R2≥0.8409)规律衰减,随风速(v)增大呈幂函数(q=avb,R2≥0.9256)规律增加,42.8%~70.7%的输沙量分布在10 cm高度内,67.6%~90.0%的输沙量分布于30 cm高度内。当地表植被盖度达到40%以上时,输沙率下降至无植被覆盖地表输沙率的6.6%以下,可有效阻止地表风蚀。(2) 沙物质主要由粒径为50~250 μm的细沙和极细沙构成,各高度层风蚀物粒度组成服从单峰态分布,峰值在100~250 μm。随高度增加,风蚀物粒径范围趋于变窄,粒径趋于更细。(3) 起沙风多出现在WSW和NW方向,占全年起沙风的53.19%。风沙流中跃移输沙、蠕移输沙的空间分布在理论上应与风向频率分布基本一致,差异性主要由各方位风的强度和持续时间等因素导致。研究结果可为该区域防沙工程设计提供理论参考。 相似文献
83.
东准噶尔贝勒库都克铝质A型花岗岩微量元素地球化学特征及地质意义 总被引:4,自引:0,他引:4
通过对新疆东准噶尔卡拉麦里地区贝勒库都克岩体的岩石地球化学特征的研究,结果表明,在贝勒库都克黑云母花岗岩中Rb、K和Th等大离子亲石元素明显富集,相对富集Zr、Hf等高场强元素,相对亏损Ba、Sr、Nb和Eu等元素,稀土元素含量相对较高,Eu的负异常极强,稀土元素配分模式呈平坦的"V"字型,属于典型的铝质A型花岗岩。该花岗岩在成因上属于A2型,形成于后碰撞的张性环境,其来源可能与洋壳和岛弧建造组成的年轻地壳有关。花岗岩微量元素构造判别图显示它是一种后碰撞花岗岩,标志卡拉麦里地区在晚石炭世造山作用的结束和板内构造演化的开始。该岩体锡质量分数普遍都比较高(15.50 10-6),为锡的成矿物质来源和锡矿矿床学的深入探索提供重要参考。 相似文献
84.
中国不同区域能源消费碳足迹的时空变化(英文) 总被引:2,自引:2,他引:2
Study on regional carbon emission is one of the hot topics under the background of global climate change and low-carbon economic development, and also help to establish different low-carbon strategies for different regions. On the basis of energy consumption and land use data of different regions in China from 1999 to 2008, this paper established carbon emission and carbon footprint models based on total energy consumption, and calculated the amount of carbon emissions and carbon footprint in different regions of China from 1999 to 2008. The author also analyzed carbon emission density and per unit area carbon footprint for each region. Finally, advices for decreasing carbon footprint were put forward. The main conclusions are as follows: (1) Carbon emissions from total energy consumption increased 129% from 1999 to 2008 in China, but its spatial distribution pattern among different regions just slightly changed, the sorting of carbon emission amount was: Eastern China > Northern China > Central and Southern China > Southwest China > Northwest China. (2) The sorting of carbon emission density was: Eastern China > Northeast China > Central and Southern China > Northern China > Southwest China > Northwest China from 1999 to 2003, but from 2004 Central and Southern China began to have higher carbon emission density than Northeast China, the order of other regions did not change. (3) Carbon footprint increased significantly since the rapid increasing of carbon emissions and less increasing area of pro-ductive land in different regions of China from 1999 to 2008. Northern China had the largest carbon footprint, and Northwest China, Eastern China, Northern China, Central and Southern China followed in turn, while Southwest China presented the lowest area of carbon footprint and the highest percentage of carbon absorption. (4) Mainly influenced by regional land area, Northern China presented the highest per unit area carbon footprint and followed by Eastern China, and Northeast China; Central and Southern China, and Northwest China had a similar medium per unit area carbon footprint; Southwest China always had the lowest per unit area carbon footprint. (5) China faced great ecological pressure brought by carbon emission. Some measures should be taken both from reducing carbon emission and increasing carbon absorption. 相似文献
85.
????????λ???????????????3????????????????????編???н??????????????????????????????????2007~2010?????20??ENVISAT ASAR?????÷????????????????????Э??????????У?????????????????й????????????Э?????????????????????3.1 mm2??????0.6mm2????????80%??e-folding???????????1.5 km?????0.21 km????????86%????????編??????Ч??У????????е??????λ????? 相似文献
86.
87.
The Orbital Evolution of Two Sounding Satellites and Analysis of the Accuracy of Orbit Determination
Gong-you Wu Chang-yin Zhao Rong-zhi Zhang Jia-song Wang Hong-bo Wang 《Chinese Astronomy and Astrophysics》2007,31(4):420-429
The satellites TC-1 and TC-2 are the two Chinese satellites with great elliptical orbits which are still in orbit around the earth at present. Since the launch the orbits of the two satellites have continuously evolved, which has a certain effect on the orbit determination and prediction precision. The regularities of the orbital evolution of the two sounding satellites are qualitatively and quantitatively analyzed. Under the current tracking mode the corresponding prediction precision of orbit determination is analyzed based on the different stages of the orbital evolution, thereby providing the basis for the adjustment of planning mode by the satellite application departments and the guarantee of normal satellite payload. Finally, the orbital lifetimes of the two satellites are predicted through the trend of the orbital evolution. 相似文献
88.
通过对我国历史上箭竹开花及王朗自然保护区箭竹生长气象条件的研究认为,箭竹开花多在冬暖夏凉的年份;箭竹的生长量可由气象因素的变化来进行预测。研究结果可为保护大熊猫提供一定的气象依据。 相似文献
89.
安徽省温泉旅游区以它独有的特色和文化的魅力赢得社会广泛的关注,也吸引更多的人对温泉旅游区的品牌建设与营销策略的研究。阐述了安徽省温泉旅游资源赋存状况,并分析安徽省温泉旅游区的品牌建设与营销策略现状。得出如下主要结论:(1)安徽省温泉多数位于隆起的大别山区、长江沿岸的巢湖—和县一带以及皖南地区;(2)产品开发利用层次不一,大多处于中程度利用;(3)温泉相关的旅游区品牌建设与营销策略相对滞后。最后在此基础上,提出现阶段安徽省温泉旅游区的品牌建设与营销策略的对策。 相似文献
90.
Fuzzy comprehensive evaluation model for water resources carrying capacity in Tarim River Basin, Xinjiang, China 总被引:12,自引:0,他引:12
This paper explores the method of comprehensive evaluation of water resources carrying capacity and sets up an evaluation model applying the fuzzy comprehensive evaluation method. Based on the data of nature, society, economics and water resources of the Tarim River Basin in 2002, we evaluated the water resources carrying capacity of the basin by means of the model. The results show that the comprehensive grades are 0.438 and 0.454 for Aksu and Kashi prefectures respectively, where the current water resources exploitation and utilization has reached a relative high degree and there is only a very limited water carrying capacity, 0.620 for Kizilsu Kirgiz Autonomous Prefecture, where water resources carrying capacity is much higher, and in between for Hotan Prefecture and Bayingolin Mongolian Autonomous Prefecture. As a whole, the comprehensive grade of the Tarim River Basin is 0.508 and the current water resources exploitation and utilization has reached a relative high degree. Thus, we suggest that the integrated management of the water resources in the basin should be strengthened in order to utilize water resources scientifically and sustainably. 相似文献