基于均方差法的郑州市土地综合承载力评价

［目的］开展土地综合承载力评价是科学编制国土空间发展战略的基础。通过构建包含水土资源承载力、经济承载力和生态承载力3个维度土地综合承载力评价指标体系，定量刻画郑州市城市土地综合承载力的特征与轨迹。［方法］运用均方差法，选取2010—2016年郑州市城市土地综合承载力评价指标，分析其土地综合承载力特征。［结果］（1）总体上，郑州市城市土地综合承载力不断增强，水土资源承载力呈现先升—降—升的动态演变特征； 经济承载力持续增长，这源于郑州市土地经济效益的大幅提升； 生态承载力呈现波动性增强的演变特征。（2）郑州市城市土地综合承载力经历了较低—中等—较高发展历程，但土地综合承载力处于低层次的较高阶段，仍有较大提升空间。（3）为提高郑州市城市土地综合承载力，应加快“多规合一”规划的编制，科学划定城市增长边界和“三生”空间，转变城市发展理念，优化发展发展路径，提升城市土地综合承载力水平。［结论］郑州市城市土地综合承载力仍有较大提升空间，应加快建立土地综合承载力扩容的有效机制。     

Influence of livelihoods on climate change adaptation for smallholder farmers in the Mekong Delta Vietnam

Farmers in the Vietnamese Mekong Delta face a wide range of climate-related and hydrological factors which threaten rice production. Smallholder farmers must adapt to climate change to sustain rice production as their central and most important livelihood activity. A sample was stratified across agro-ecological areas in the Delta affected by flooding, alluvial soils, acid sulphate soils, and saline water intrusion and by derived farmer typologies. A rural livelihoods approach was used in focus group discussions and in-depth interviews to identify and enumerate enabling and constraining adaptation factors. Smallholders experienced diverse natural hazards such as floods, abnormal rains, high temperatures, water scarcity, and salinity intrusion specific to the agro-ecological areas. Adaptation was constrained by labour shortages, water quality, topography, access to combine harvesters, transportation infrastructure, dryers and household savings. Adaptation was enabled by farming techniques and experience, cooperative groups, water quantity, access to information, and ability to purchase agro-chemicals through credit. Small farmers (< 1?ha) were more constrained than large farmers (> 1?ha) who had an expanded livelihood asset base. A range of policy implications are discussed, but adaptation is not just about technological fixes but requires overall improvements in a range of human, social and financial components.     

一类有向网络的容量扩张问题研究

将网络容量定义为最大流的流量。针对网络容量的三种扩张方式：点扩张、弧扩张、点扩张和弧扩张相结合,分别建立数学模型,提供算法;在分开讨论的基础上,还提出了统一的容量扩张模型;最后提供了一个具体算例。     

Tourism as an alternative source of regional growth in Portugal: a panel data analysis at NUTS II and III levels

The role of tourism is of vital economic importance, particularly for small countries with a privileged geographical location and favourable weather conditions. This paper examines the importance of tourism as a conditioning factor for higher regional growth in Portugal by employing the conditional convergence hypothesis of Barro and Sala-i-Martin, associated with the endogenous growth theory. The panel data estimation approach provides evidence of the positive impact of tourism (through the accommodation capacity) on the growth in per-capita income among the Portuguese regions, increasing the rate of convergence. Therefore, tourism can be considered as an alternative source for stimulating higher regional growth in Portugal, if the supply characteristics of this sector are improved.     

随机生产前沿方法的发展及其在中国的应用

本文对随机前沿生产函数模型的发展及其在中国生产率分析中的应用进行了评述。文章首先介绍随机前沿方法的基本原理、估计方法和在面板数据下对全要素生产率增长的分解,随后评述随机前沿生产函数模型的最新进展和在经验分析中的优势与作用,最后总结了在中国行业和地区经济增长研究中随机前沿方法的成果和不足,并探讨今后研究的发展方向。     

现代物流产业国际竞争力生成模型的构建研究

通过对国际竞争力相关理论和因素的分析,构建了现代物流产业国际竞争力生成模型,最后并对我国现代物流产业国际竞争力的形成机制进行了分析.最后提出了进一步提升我国现代物流产业国际竞争力的措施.     

Understanding the Large Negative Impact of Oil Shocks

This paper offers a plausible explanation for the close link between oil prices and aggregate macroeconomic performance in the 1970s. Although this link has been well documented in the empirical literature, standard economic models are not able to replicate this link when actual oil prices are used to simulate the models. In particular, standard models cannot explain the depth of the recession in 1974–75 and the strong revival in 1976–78 based on the oil price movements in that period. This paper argues that a missing multiplier-accelerator mechanism from standard models may hold the key.     

水泥土搅拌桩复合地基承载力的灰色预测

详细阐述灰色模型的建立及调整过程,利用复合地基沉降实测数据,根据灰色系统理论,建立(1,1)模型,可模拟复合地基的P~s曲线,预测地基沉降的发展趋势,分析水泥土搅拌桩复合地基的承载性能。     

应该用哪一个模型来描述中国货币市场利率的动态变化

本文论证了双曲模型是描述中国货币市场利率动态变化的最佳单因子利率模型。由极大似然估计可以得到单因子利率模型的边际密度函数。双曲模型的边际密度和非参数估计得到的边际密度函数拟合较好，其表现远远优于几个常见的利率模型（CIR、CKLS和AG模型）。与较一般的Ait-Sahalia模型相比差别很小，但参数形式得到简化，似然比检验也支持这一点。双曲模型在刻画利率的均值回复特征方面还克服了AG模型的不足。     

东部沿海地区利用FDI能力比较研究

由于巨大的国内市场需求、有竞争力的“制造成本”以及入世后服务业领域的相继开放政策,中国已经成为全球外商直接投资的主要吸收国,但各地区在利用外资能力上表现很不平衡。如何评价各地区利用外资的能力,具有重要的政策含义。本文认为一个地区利用外资能力由其获取外资能力和运用外资能力两个层面决定。基于此,我们提出一套评估地区利用外资能力的指标体系,然后通过因子分析,对东部沿海地区8个省市利用FDI能力进行评估和比较。政策含义在于提升利用外资能力应当从获取外资能力和运用外资能力两个方面进行。