贫困视角下的中国区域经济增长规律及其管治研究

采用贫穷增长曲线方法,研究了中国的区域经济增长规律。根据中国1994~2006年地级市的人口和GDP数据,总体来看,随着经济增长,中国地区差距呈扩大趋势,但区域平均GDP增长率越高,地区差距拉大的趋势就越小。1998~2000年,受亚洲金融危机影响,中国呈现贫困化经济增长,GDP增长率最低,地区差距急剧扩大;2003~2004年是亚洲金融危机后中国平均GDP增长率最高的年份,基本符合减贫经济增长,地区差距缩小;其余年份基本符合涓滴经济增长,即随着经济增长,虽然绝对贫穷得到了缓解,但贫困地区人口的收入份额降低,地区差距扩大。针对这种情况,提出了中国经济增长的区域管治是必要的。     

南极磷虾的生长与复眼直径关系的研究

本文对南极磷虾复眼的直径与磷虾体长之间的关系、在负生长状态下磷虾复眼直径的变化等进行了研究。实验结果表明：在正常情况下（磷虾身体不出现负生长），磷虾复眼的直径与体长之间存在指数函数关系。雌性磷虾的眼径（ＥＤ）与体长（ＢＬ）之间的关系为：ＥＤ＝０．５８９８ｅ０．０２８２ＢＬ（ｒ＝０．９６１３，ｎ＝２４１９）；雄虾的眼径与体长之间的关系为：ＥＤ＝０．５４４ｅ０．０３０９ＢＬ（ｒ＝０．９６２２，ｎ＝１９２０）。在相同体长的情况下，雄性磷虾的复眼直径比雌虾的大。从活体培养的结果来看，当南极磷虾出现负生长时，复眼直径保持不变，即眼径不受负生长的影响。在正常情况下（不存在负生长），雌虾的体长与眼径之间的比率（ＢＬ／ＥＤ）平均为２１．３２±０．０４（ｎ＝１３４７），雄虾的体长与眼径之间的比率平均为２０．６８±０．０７（ｎ＝７４８），未成体虾的体长与复眼直径之间的比率平均为２１．５４±０．０６（ｎ＝１０７２）。利用体长与眼径之间的比率可以准确地将在实验室内活体培养后已存在负生长的磷虾与其它处于正常状态的磷虾分开。体长与眼径之间的比率也可以作为磷虾种群是否存在负生长的监测指标     

城市化水平增长曲线的类型、分段和研究方法

城市化水平增长曲线可以分为S形和J形2大类别,其变化特征、动力学背景及研究方法也不尽相同。城市化曲线研究可以分为唯象分析和唯理分析2大途径,唯理研究包括城一乡人口异速生长、城一乡人口替代以及城乡人口迁移和转换3种路径,目前这些方法主要用于S形曲线研究,对J形曲线的探索不够深入。S形曲线是一种奇对称曲线,其模型导数却是一...     

浅水环境下多次反射折射波条带范围的研究

浅水地震资料中,直达波上方会出现一个明显的“扫帚状”的条带,确定其地震波成份有利于对地震传播规律的认识,可为海上实际作业建立合适的观测系统提供参考依据,同时也可为后期资料处理提供理论依据。本文在陆地多次反射折射波传播路径分析的基础上,通过对简单模型的数值模拟结果分析,确定了浅水环境中位于直达波上方的“扫帚状”条带为海底表层介质产生的多次反射折射波的整体反映。定量分析了多次反射折射波的“扫帚状”条带的范围及其影响因素,并结合实际地震资料进行了验证。     

THE FLUCTUATIONS OF ITALIAN GLACIERS DURING THE LAST CENTURY: A CONTRIBUTION TO KNOWLEDGE ABOUT ALPINE GLACIER CHANGES

This paper describes the recent evolution of Italian glaciers through an analysis of all available terminus fluctuation data that the authors have entered in a glaciers database (named GLAD) containing 883 records collected on glaciers from 1908 to 2002. Furthermore, a representative subset of data (249 glaciers located in Lombardy) was analysed regarding surface area changes. For the analysis of terminus fluctuations, the glaciers were sorted by size classes according to length. The data showed that during the 20th century Italian Alpine glaciers underwent a generalized retreat, with one distinct and well documented readvance episode that occurred between the 1970s and mid‐1980s, and a poorly documented one around the early 1920s. The rates of terminus advance and retreat have changed without significant delays for the larger glaciers with respect to the smaller ones. However, the smaller the glacier, the more limited the advance (if any) during the 1970s and early 1980s. The behaviour of glaciers shorter than 1 km appears to have changed in the last decade, and between 1993 and 2002 they retreated at a very high rate. The analysis of the subset of data led to a quanti‐fication of surface reduction of c. 10% from 1992 to 1999 for glaciers in Lombardy. Small glaciers proved to contribute strongly to total area loss: in 1999, 232 glaciers (c. 90% of the total) were smaller than 1 km², covering 27.2 km² (less than 30% of the total area), but accounted for 58% of the total loss in area (they had lost 7.4 km²).     

长江上游干支流近期水沙变化及其与水库修建的关系

基于水文站实测的长系列水沙资料,运用统计方法研究了长江上游干支流的近期水沙变化.屏山站年输沙量的变化自1999年以后开始减小,扭转了1980～1998年的增加趋势.高场站年输沙量由1990～2000年的减小趋势,变化为2000～2007年的增大趋势.北碚站的年输沙量呈进一步减少的趋势.武隆站年输沙量改变了1990～2000年的增加趋势,2000～2007年显著减小.宜昌站的年输沙量延续了从20世纪80年代中期以来的减少趋势,2002～2007年急剧减小.采用输沙量-径流最双累积曲线方法进行了分析,发现各站双累积曲线上最近一次转折点的出现,均与水库的修建有关.基于双累积曲线估算了近期各站的减沙量(或增沙量).研究还发现,近期屏山、北碚、武隆、宜昌4站含沙量均呈现减小趋势,与水库的拦沙作用密切相关.但是,岷江近期水电梯级开发的大规模展开,巨量弃土、弃渣进入河道,导致了2002～2007年间含沙量的增大.建立了宜昌站年输沙量与长江上游流域内累计水库库容量及宜昌站年径流量之间的回归方程,估算出它们对于长江上游产沙量变化的贡献率分别为71.4%和28.6%.这表明,水库拦沙是导致长江上游产沙量减小的主要原因.     

东北三省城镇收缩的特征及机制与响应

基于城镇收缩视角认识东北三省人口流失与经济衰退问题,对深化中国老工业基地转型理论具有重要意义.本文以东北三省县级市(县)为研究对象,利用ArcGIS与空间计量方法,分析增长与收缩城镇的特征与空间关系,研究收缩城镇的职能差异和空间分布格局,探讨区域城镇收缩的形成机制与应对措施.结果 显示:2000年以来,东北三省出现了明...     

Analyzing the runoff response to soil and water conservation measures in a tropical humid Ethiopian highland

Abstract

Different soil and water conservation (SWC) practices have been implemented in many drought-prone parts of Ethiopia since the 1980s. We assessed the effect of SWC practices on runoff response and experimentally derived and tested the validity of the runoff curve number (CN) model parameter for the tropical humid highland climate of the Kasiry watershed in northwestern Ethiopia. We recorded daily rainfall and runoff depth from 18 runoff plots (30 m long × 6 m wide) representing the five main land-use types with various SWC practices and two slope classes (gentle and steep). CN values were derived using the lognormal geometric mean CN procedure. Runoff was significantly less from plots with SWC measures, with average reductions of 44 and 65% observed in cultivated and non-agricultural lands, respectively. Runoff on plots representing non-agricultural land was relatively accurately predicted with the derived CN method, but predictions were less accurate for plots treated with a SWC practice. We conclude that predicting the effect of SWC practices on runoff requires parameterization with separate sets of CN value for each SWC practice.     

生态补偿：概念框架与应用研究

通过对生态补偿内涵的深入分析,首先把生态补偿的概念区分为人际补偿和人地补偿2个相互联系的方面,并指出其研究意义;其次,利用1986-2005年福建经济与环境统计数据,通过EKC曲线模型分析福建省环境质量的变化趋势,得出现阶段福建省总体环境状况仍处在污染继续加重的结论,并对其原因做了简要分析;最后,基于实证研究所得结论,运用人际补偿和人地补偿的概念框架,参照国际上发达国家的经验,对福建省环保投入的合理数额、生态补偿机制的规范和创新等问题进行了探讨。提出人地补偿必须注重时空合理配置和其效率有赖于入际补偿机制创新等观点。     

Israel's petroleum discovery curve

Oil exploration in Israel began in 1953. Until 1991 a total of 263 exploration wells and 122 development wells were drilled, 3 oil fields and 5 gas fields were discovered, and 4 noncommercial oil discoveries and 1 noncommercial gas discovery were made. Proven in-place reserves amount to 70 million barrels of oil equivalent (MMBOE). Exploration focused on six main plays: Syrian Arc anticlines; Mesozoic platform-edge, structural-stratigraphic traps; the Dead Sea graben; Early Mesozoic structures; Saqiye Group biogenic gas; and Hula Group biogenic gas. The more significant discoveries are associated with the first two plays. Ninety percent of the proven reserves were discovered by the first 71 wildcats, which constitute 27 percent of all wildcats drilled to date. During this phase of exploration, the average success was 7 percent, and the average discovery rate was 0.88 MMBOE per wildcat. Most of the following 192 wildcats were dry holes. If, as experts claim, significant reserves are still undiscovered, previous exploration must be deemed inefficient. The quantitative model of the discovery process also leads to such an assessment.