Urban three-dimensional expansion and its driving forces —A case study of Shanghai, China

Urban expansion is a phenomenon of urban space increase, and an important measuring index of the process of urbanization. Taking Shanghai as an example, the changes of urban average height and built-up area were studied to represent city’s vertical and horizontal increases respectively, and statistical methods were used to analyze the driving forces of urban expansion. The research drew following conclusions: 1) The urban expansion process of Shanghai from 1985 to 2006 had a clear periodic feature, and could be divided into three stages: vertical expansion in dominance, coordinated vertical and horizontal expansion, and horizontal expansion in dominance. 2) The average height and quantity of buildings in core city were significantly bigger than those in suburbs, but the changing speed of the latter was faster. And 3) urbanization process was the major driving force for the city’s horizontal expansion, while industrial structure improvement was the key driving factor for the vertical expansion. Those two driving forces were simultaneously affected by city’s political factors.     

SUSTAINABLE DEVELOPMENT OF THE SERIOUSLY POLLUTED CITIES IN CHINA——Taking Benxi City as an Example

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Soil evolution features of debris flow waste-shoal land

The reclamation and utilization of debris flow waste-shoal land plays an important role in the mitigation and control of debris flow hazards, which thus contributes a lot to the exploitation of insufficient land resources in mountainous areas and the reduction of losses caused by debris flow. The aim of this paper is to discuss the features and mechanism of soil evolution of debris flow waste-shoal land so as to search for the available modes of its reclamation and utilization. The Jiangjiagou Ravine, a typical debris flow ravine, was selected to study soil evolution features of debris flow waste-shoal land based on the analysis of soil physieochemical properties and soil microstructure. It was found that the soil evolution rates of debris flow waste-shoal land varied with different modes of reclamation. For the land which had been reclaimed for less than lO years, soil evolved most rapidly in paddy fields, and more rapidly in dry farmland than in naturally restored waste-shoal land. For the land which had been used for more than lo years, the soil evolution rates of dry farmland, naturally restored waste-shoal land and paddy farmland decreased in the file. For the same utilization period of time, significant differences were recognized in soil evolution features under different modes of reclamation. Analysis data showed that soil clay content, soil thickness, the psephicity of skeleton particles and contents of microaggregates （〈0.02 mm） in paddy farmland were all highest. Soil nutrients and porosity of dry farmland were better than those of paddy farmland and naturally restored waste-shoal land, and those of paddy farmland were superior to those of naturally restored waste-shoal land. Paddy farmland characterized by rapid pedogenesis, stable evolution and high utilizability was the priority candidate for the reclamation and utilization of debris flow waste -shoal land.     

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石油污染土壤对向日葵生长的影响

以美国油料向日葵G101为材料,通过田间试验,研究了土壤石油污染质量浓度为10 000 mg/kg时,对向日葵生理性状、产量性状、农艺性状及籽仁质量的影响。结果表明:石油污染土壤对向日葵群体叶面指数从苗期至成熟期均有显著影响。葵盘直径、茎秆直径、株高、叶片数、百粒重和生物量分别缩小或降低10.7%、7.4%、7.2%、10.0%、16.7%和21%;空秕率提高2.4倍;对根系与地上部分的抑制作用无显著差异。该污染浓度下石油对向日葵发芽出苗率,籽仁中粗脂肪和粗蛋白质含量无显著影响;葵盘腐烂病发生率、分枝发生率有所提高。     

奎屯河流域包气带盐分分布特征与影响因素

通过对奎屯河流域包气带土壤取样分析,探讨了土壤包气带的盐分分布特征和影响因素。结果表明,在水平方向上,由南至北,表土含盐量逐渐增大。在垂直方向上,在地下水位埋藏较浅的细土平原及冲积平原区,包气带含盐量随深度增加逐渐减小;在人工耕地洪泛冲积平原、细土平原则呈随深度的增加而增加的趋势;包气带岩性结构较单一且潜水位埋藏比较深的地区,包气带含盐量随深度增加而出现微小波动。分析结果显示：地形、地貌和潜水位埋深是影响该区包气带盐分分布的主控因素,而人为的大面积灌溉又加速了积盐的过程。     

轮廓波变换在遥感目标图像检索中的应用

除具有纹理属性外,遥感图像中还包含大量的结构性边缘特征。如何有效捕捉这些特征中的信息进行检索,成为提高遥感图像检索效率的关键。依据Contourlet在离散域的多尺度几何分析的功能,提出一种利用Contourlet子带能量分布特性提取原始图像在多个尺度下的边缘方向信息进行检索的方法。针对Cont-ourlet变换响应不同特征方向能力的差别,采用正交补偿法加以改正,经过傅里叶算子的处理,从而实现旋转不变结构性边缘特征的检索。最后,在遥感目标图像上所作的实验证实了该算法的有效性。     

Sedimentary macro-structures and forming mechanism of debris flow

IIWr~IOWThesedimentarycharacteristicsofdebrisflowcanreflectthecompoSition,fluidtypeandsedimentaryprocess.ThescholarswhostudymoderndebrisfloWinChinagenerallyclassifydebrisflowbythemethodofviscositywithfloWpattern.SeveraltypicalschemesareshowninTable1,inwhichthemethodofunitweight(fluiddensityinunitvolumet/m3)isusedandfluidunitweightisthoughttobethedirectproPOSitiontotheviscosityofdebrisflow(Wu,1990).Ithasbeenprovedbyhydrcrmechacsthatnon-cohesivedebrisf1OwfollowsBagnoldgranular'flowmedel(B…     

The generation and its sealing condition of natural gas in the Tadong area

Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir, the kinetics of oil cracking gas and the evaluation parameters of gas cap rock are adopted to the study on the natural gas accumulation conditions in the Tadong area. Both the study on the kinetics of oil cracking gas and the statistical results of reservoir bitumen reveal that the geological formation of oil cracking gas in the Tadong area is located in the top of Cambrian. Two kinds of oil cracking gas geological models at least, namely well Mandong-1’s early rapid generation model (Middle Ordovician-end Silurian) and peak cracking model (with the natural gas conversion rate >90%), namely well Yingnan-2’s two-stage generation model of oil cracking gas, have been set up. The oil cracking gas of Yingnan-2 in the late stage is very significant in the evaluation of natural gas exploration in the Tadong area. The evaluation results of the cap rock show that the microscopic parameters of cap rock from the lower assemblage of Cambrian-Ordovician are better than those from the upper assemblage. The former has strong capillary sealing ability and higher cap rock breakthrough pressure than the upper assemblage, with strong sealing ability, so that natural gas dissipates mainly by diffusion. According to the above investigations, the lower assemblage Cambrian-Ordovician natural gas of Kongquehe slope, Tadong low uplift and Yingjisu depression in the Tadong area prospects well.

     

包头—忽鸡沟一带麻粒岩相岩石的矿物学和结晶P-T条件

本文提供了77个石榴石、辉石、角闪石、黑云母和斜长石等单矿物能谱和湿化学分析资料,研究了各种矿物对的分配系数。用二辉石地质温度计估算的变质作用温度为770—860℃,用其他矿物对估算的温度多数在二辉石温度计获得的温度范围内。用Wood的石榴石—斜方辉石地质压力计和Newton—Perkins以及Wells石榴石—斜方辉石—斜长石地质压力计公式估算的变质作用压力为(8—10)×10~8Pa,地热梯度为24.6—27.5℃/km,属低—中压型麻粒岩相。