左江洪涝特征分析

台风是造成左江洪涝的主要影响系统,后汛期洪涝频率明显高于前汛期,洪水汇流量与降雨性质、地形地貌、土壤含水量有关,依不同降雨量径流量不同的原理及洪涝特征估测洪水量、洪峰流量较接近实况,具有应用价值。     

中国区域经济发展差异的实证研究与R/S分析

文章回顾了改革开放以来中国经济发展战略的转变，介绍了吉尼系数，区域经济区位熵和Hausdoeff Index的计算方法。采用GDP指标，运用吉尼系数和区域经济区位熵分析了改革开放以来中国三大地带之间，省区之间的绝对差距和相对差距的变化趋势，而且还运用分形理论和R／S方法研究了中国区域经济发展差异的收敛性，得出的结论如下：（1）无论从绝对差距还是从相对差距上看，自改变开放以来中国三大地带之间或省区之间的经济发展差距都在扩大。（2）1995年所实施的区域协调发展战略在近期内并没有缩小地区之间的发展差距。（3）R／S分析结果表明中国区域经济发展差异在未来20年内将继续扩大。     

单个备选假设的可区分

根据单个备选假设的统计检验,详细导出了模型误差的可区分度公式,并论述了可区分度与可发现度及与Forstner法的关系。作为应用,可导出变形模型的可区分度及网的可区分标准,在监测网的设计中应用。     

山西大同新生代火山岩熔融相平衡的实验研究

通过低压熔融相平衡实验，研究山西大同火山群玄武岩在结晶分离作用过程中液相成分的演化规律，探讨了矿物和溶浆之间元素的分配。在１００ｋＰａ，ｆｏ２＝ＮＮＯ，Ｔ＝１１００°～１３００℃条件下，矿物结晶顺序为Ｏ１→Ｐ１→Ｃｐｘ。橄榄石为液相线矿物。橄榄石－熔体Ｆｅ２－－Ｍｇ２－交换反应的分配系数是一个与温度无关的常数、残余液相线成分取决于晶出矿物相的化学成分及含量。Ｏ１＋ＣｐＸ＋Ｐ１饱和液相成分的Ｏ１－Ｄｉ－Ｓｉｌ和Ｏ１－Ｄｉ－Ｎｅ三元系相图清楚地反映了熔岩低压结晶作用的趋势，低压下熔浆的主要元素变化很大程度上依赖于母岩浆ＳｉＯ２饱和程度。     

Application of Hydrophobic Interaction Chromatography (HIC) in Water Analysis Anwendung der Hydrophobizitätschromatographie (HIC) in der Wasseranalytik

Dissolved high molecular weight organic substances, like humic substances, can be characterized with regard to their molecular weight distribution using gel filtration chromatography (GFC). In addition, the adsorption properties, for example on activated carbon, can be described, if the substances are separated by hydrophobic interaction chromatography (HIC) in different fractions using a chromatographic column with a hydrophobic matrix. The retention time (Rt) of single chemical substances in this column can be used to characterize the hydrophobicity or hydrophility of each compound as well as of the high molecular weight organic matter. The hydrophobic interaction between the matrix of the column and the dissolved chemical compounds also depends on the hydrophobicity of the gel and the composition of the eluent. Relations between retention times, log P-coefficients (octanol/water partition) and K-values of isotherms on activated carbon (Freundlich equation) were found.     

Behaviour of Different Molecular-weight Fractions of DOC of Elbe River Water during River Bank Infiltration

This paper reports changes in dissolved organic carbon concentration β(DOC) and the relation between UV-active and non-UV-active components determined for Elbe river water and river bank infiltrate in the Torgau river basin between 1992 and 1994. Using an ultrafiltration method, the fractionation of the DOC content was obtained for the fractions > 10 000 g/mol, 1 000…10 000 g/mol, and < 1 000 g/mol. The spectral absorption coefficient at 254 nm a₂₅₄ of the molecular-weight fractions was also measured. The mean total DOC concentration of Elbe river water decreased from 6.0 mg/L to below 3.9 mg/L along two investigated flowpaths. Two thirds of the decrease occurred within the first few metres of the river bed and one third along the 350 m length of the groundwater flowpaths. The a₂₅₄ values showed a significant decrease from 14.8 1/m in Elbe river water to 7.8 1/m in the aquifer. Along a flowpath, the proportion of low-molecular weight fraction of DOC increased, the proportion of high-molecular weight fraction decreased, and the proportion of the 1 000…10 000 g/mol molecular-weight fraction remained relatively stable. The Elbe river water contained the main portion of UV-active compounds in the fraction 1 000…10 000 g/mol, and this was also the case for samples of river infiltrate. For the high-molecular weight fraction, mainly non-UV-active compounds were attenuated in the river bed sediment.     

Experimental investigation of the effect of grading characteristics on the liquefaction resistance of various graded sands

The liquefaction susceptibility of various graded fine to medium saturated sands are evaluated by stress controlled cyclic triaxial laboratory tests. Cyclic triaxial tests are performed on reconstituted specimens having global relative density of 60%. In all cyclic triaxial tests; loading pattern is selected as a sinusoidal wave form with 1.0 Hz frequency, and effective consolidation pressure is chosen to be 100 kPa. Liquefaction resistance is defined as the required cyclic stress ratio which caused initial liquefaction in 10 cycles during the cyclic triaxial test. The results are used to draw relationship between grading characteristics (e.g. coefficient of uniformity and coefficient of curvature) and the liquefaction resistance of various graded sands. It is found that a relationship between cyclic resistance and any of the size (i.e. D₁₀, D₃₀ or D₆₀) would be more realistic than to build a relation between grading characteristics and the cyclic resistance.     

环渤海地区城市密集区的空间识别与集聚特征

在探讨城市密集区内涵和特征的基础上,以环渤海地区118个城市为研究区域,通过空间识别确定了6个城市密集区范围;利用城市GDP和人口数据,借助Theil系数、城市基尼系数和首位城市集聚度等方法,从空间差异、集聚程度和集聚效应三方面对城市密集区的集聚特征进行探究。结果显示:(1)以城市等级和社会经济数据为筛选标准确定了北京、天津等7个中心城市、38个标准市和77个其他城市;(2)以2 h通行时间确定了以京津、石家庄、沈阳、大连、济南和青岛为核心的城市密集区范围;(3)Theil系数表明环渤海地区整体差异较小,其中城市密集区区内差异大于区际,内部差异对整体差异的贡献率超过91%;(4)集聚类型划分中,京津地区属于强单中心,沈阳、大连和青岛地区属于弱单中心,济南和石家庄地区被归入弱多中心类型;(5)京津城市密集区强大的集聚效应破坏了"石家庄—黄骅"的双核结构链,重新构建了区域的经济结构格局。     

城乡收入不平等对城乡居民消费差距的影响

基于1997—2013年中国内地31个省份的省级面板数据,将收入、消费的基尼系数纳入研究框架,从城乡居民消费差距水平和结构两个层面考察城乡居民收入不平等对城乡居民消费差距的影响。研究发现:各地区城乡收入不平等状况恶化均显著扩大了城乡居民消费水平差距;非线性检验结果表明,全国和东部地区城乡居民消费差距呈倒"U"型,并处于其下行区域,即城乡收入不平等对城乡居民边际消费差距的作用是递减的;中、西部地区城乡居民消费差距处于"U"型曲线的上行区,即城乡收入差距的上升造成城乡居民消费差距越来越大;从城乡居民消费结构差距的角度看,现阶段的城乡居民收入差距对不同类别的城乡居民消费支出差距的影响是不确定的,而且消费差距存在显著的棘轮效应。