Geographic Patterns of Air Passenger Transport in China 1980–1998: Imprints of Economic Growth,Regional Inequality,and Network Development*     

Fengjun Jin  Fahui Wang  Yu Liu 《The Professional geographer》2004,56(4):471-487

This research analyzes the geographic patterns of domestic air passenger transport in China from 1980 to 1998, with three foci: (1) impacts of economic reforms, (2) regional inequality in air transport development, and (3) network development. Accessibility to air transport improved significantly as China expanded its air transport system, 1980–1998. The dominance of major airports declined as the air transport system expanded to medium and small cities. The centroid of passenger volume migrated toward southeast, consistent with the expansion of economic growth in southeast coastal areas. The rule of distance decay in air traffic was more applicable to China in 1998 than in 1985 as the market economy worked its way into China's air transport system. The East Region had a much higher share of air passengers than its share of population and GDP, followed by the West and the Middle Regions, reflecting an interesting “flyover” effect. By 1998, a hub‐and‐spoke air transport system was clearly in place in China.  相似文献   

利用MODIS遥感影像获取近地层气温的方法研究   总被引：15，自引：1，他引：15  

齐述华  王军邦  张庆员  骆成凤  郑林 《遥感学报》2005,9(5):570-575

由于冠层叶片群体效应,在1km的空间尺度上遥感获取浓密植被陆面温度与气温近似相等。根据这个原理对利用遥感手段获取气温进行了尝试,提出利用NDVI-Ts空间获取气温的方法,计算气温空间分布模式,同时对Prihodko和Goward提出的气温遥感获取模型(简称P-G模型)进行试验并与NDVI-Ts空间法进行了对比。根据Parton和Logan提出的气温尺度转换模型,利用气象站观测最高气温和最低气温获取Terra卫星过境时刻气温作为“测定值”,对遥感获取的气温进行检验,得到以下结论:P-G模型计算气温与观测结果相比偏高,而NDVI-Ts法计算结果偏低,但是其总体误差范围相当,大约为 4℃;与P-G模型相比,尽管NDVI-Ts空间法获得的气温在精度上对P-G模型没有多大的改善,但这种方法能够更加充分利用遥感获取的信息,而且在计算机运算效率上也有很大的改进,NDVI-Ts空间法相对于P-G模型具有一定优势。  相似文献   

夏季500 hPa副热带高压区域一次暴雨过程环流条件的诊断分析   总被引：4，自引：2，他引：4       下载免费PDF全文

章国材  李晓莉乔林 《应用气象学报》2005,16(3):396-401

利用NCEP/NCAR再分析资料和地面观测资料对2003年7月26～27日500 hPa副热带高压区域一次暴雨过程的形成原因进行了分析。结果表明:中低层来自东北方向的冷空气入侵是此次暴雨发生的重要原因，其作用体现在三个方面:一是致使对流层中低层降温，边界层增温，使得降水区积累了大量的不稳定能量；二是造成边界层风的辐合，进而激发了整层的上升运动；三是这股冷空气为暴雨发生提供了重要水汽源。暴雨发生前南亚高压主体突然东进，高空急流轴不断东伸加强，其出口端不断向南伸展，使得对流层中层副高主体西移，同时造成日本附近的冷涡南压，为冷空气从中低层侵入暴雨发生区提供了有利的环流条件。  相似文献   

Climatic significance of δ18O records from an 80.36 m ice core in the East Rongbuk Glacier, Mount Qomolangma (Everest)     

Zhang Dongqi  QIN Dahe  HOU Shugui  KANG Shichang  REN Jiawen  Paul A.Mayewski 《中国科学D辑(英文版)》2005,48(2)

The δ18O variations in an 80.36 m ice core retrieved in the accumulation zone of the East Rongbuk Glacier, Mount Qomolangma (Everest), is not consistent with changes of air temperature from both southern and northern slopes of Himalayas, as well as these of the temperature anomalies over the Northern Hemisphere. The negative relationship between the δ18O and the net accumulation records of the ice core suggests the "amount effect" of summer precipitation on the δ18O values in the region. Therefore, the δ18O records of the East Rongbuk ice core should be a proxy of Indian Summer Monsoon intensity, which shows lower δ18O values during strong monsoon phases and higher values during weak phases.  相似文献   

上流式曝气生物滤池深度处理炼油厂外排污水   总被引：4，自引：0，他引：4  

崔康平  钟佐燊  沈照理 《地学前缘》2005,12(Z1):55-60

炼油厂外排污水水质复杂,可生化性已较差,但上流式曝气生物滤池对其有较好的处理效果.研究结果表明曝气生物滤池处理炼油厂外排污水在有机负荷(COD)为 4.39 kg·m-3·d-1、水力负荷为3 m3· m-2·h-1、气水比为31下,COD、NH3-N的去除率达到81.9%、73.2%;曝气生物滤池的主要影响因素依次是水力负荷、气水比、有机负荷;得到的经验速度方程与Monod方程基本吻合.该实验为炼油厂外排污水再生回用提供了一种工艺方法.  相似文献   

流速对D403型树脂从盐湖卤水中提取硼酸的影响研究          下载免费PDF全文

孔亚杰  李海民  韩丽娟 《盐湖研究》2006,14(1):46-48

针对流速对D403型苯乙烯系多羟基类弱碱性硼特效离子交换树脂从盐湖卤水中提取硼酸的影响进行了研究,讨论了这种树脂对硼的吸附量与卤水流速的关系。  相似文献   

Palaeolimnological Development of Lake Njargajavri, Northern Finnish Lapland, in a Changing Holocene Climate and Environment   总被引：1，自引：2，他引：1  

Kaarina Sarmaja-Korjonen  Marjut Nyman  Seija Kultti  Minna Väliranta 《Journal of Paleolimnology》2006,35(1):65-81

This study used palaeolimnological approaches to determine how Holocene climatic and environmental changes affected aquatic assemblages in a subarctic lake. Sediments of the small Lake Njargajavri, in northern Finnish Lapland above the present treeline, were studied using multi-proxy methods. The palaeolimnological development of the lake was assessed by analyses of chironomids, Cladocera and diatoms. The lake was formed in the early Holocene and was characterized by prominent erosion and leaching from poorly developed soils before the establishment of birch forests, resulting in a high pH and trophic state. The lake level started to lower as early as ca. 10,200 cal. BP. In the resulting shallow basin, rich in aquatic mosses, pH decreased and a diverse cladoceran and chironomid assemblage developed. It is likely that there was a slight rise in the water level ca. 8000 cal. BP. Later, during the mid-Holocene characterized by low effective moisture detected elsewhere in Fennoscandia, the lake probably completely dried out; this is manifest as a hiatus in the stratigraphy. The sediment record continues from ca. 5000 cal. BP onwards as the lake formed again due to increased effective moisture. The new lake was characterized by very low pH. The possible spread of pine to the catchment and the development of heath community may have contributed to the unusually steep (for northern Fennoscandia) decline in pH via change in soils, together with the natural decrease in leaching of base cations. Furthermore, the change in pH may have been driven by cooling climate, affecting the balance of dissolved inorganic carbon in the lake.  相似文献   

Linear pressurization method for determining hydraulic permeability and specific storage of a rock sample   总被引：1，自引：0，他引：1  

I. Song  J. Renner 《Geophysical Journal International》2006,164(3):685-696

  相似文献   

Geographic Perspectives of Air Transportation   总被引：1，自引：1，他引：1  

Timothy M. Vowles 《The Professional geographer》2006,58(1):12-19

Past, present, and future research directions and advances in this highly dynamic research area of air transportation are reviewed with an eye toward geographers' contributions to the air transportation industry. The study of air transportation within the field of transportation geography and the larger discipline of geography is important as geographers use air transportation to help describe concepts such as connectivity and linkages, development patterns at various scales, and the global economy. This article takes three approaches in exploring geographers' contributions to research in the field: historical, publication outlets, and topic focus. The goal of the article is to commemorate the contributions of pioneer and current researchers in the field, and open to discussion future research paths in air transportation.  相似文献   

Calculated and measured values of liquid water content in clean and polluted environments     

J. Fišák  D. Řezáčová  J. Mattanen 《Studia Geophysica et Geodaetica》2006,50(1):121-130

The relationship between liquid water content (LWC) and visibility (VIS) in a fog was examined by a field measurement of LWC values at a clean location of the meteorological observatory Sodankylä (Finland) and in a polluted region at the meteorological observatory Mile?ovka (Czech Republic). Furthermore, the use of a simple regression fog model to determine LWC from VIS is examined by comparing well-known relationships with the measurement results. The results show that the verbal characterization of environment (clean, mild polluted, polluted) is insufficient to calculate the LWC values from visibility. It is necessary to establish an additional criterion based on quantitative fog characteristics or to determine the site-related equation from the previous LWC and VIS measurement.  相似文献