盘锦30万吨原油码头超硬地层沉桩施工技术

在标准贯入度达到60击以上的较厚极密实砂土地层沉桩时,受船机设备性能限制通常会采用冲水沉桩等施工工艺,而配备D-180柴油锤的"葛飞腾2"超大型打桩船合理利用船机性能,采用动态控制锤击过程的施工方法可以直接穿透此类地层,效果良好。     

深部沿空掘巷窄煤柱合理宽度数值模拟分析

合理的煤柱宽度能够保证工作面巷道的稳定性,改善沿空掘巷维护状况,降低由于矿山压力造成的巷道变形,煤柱宽度的确定对于提高煤柱回收率、保障安全高效的生产起到积极作用。本文针对煤矿沿空掘巷具体生产地质条件,采用数值计算及现场试验相结合的方法,研究了沿空掘巷窄煤柱的合理的煤柱宽度,得到S2105瓦斯排放巷和S2106回风巷之间合理煤柱宽度为8 m,为该矿地质条件下煤柱留设的合理宽度确定提供了理论依据。     

城镇化进程中水资源消耗的影响因素研究

在"多项连乘和加总"及向量扩展形式的LMDI模型基础上,构建城镇化进程中人口-居民消费-用水强度的分解框架,分析2003—2016年间水资源消耗的影响因素。研究表明:人口规模扩大和人口城镇化对用水量增长均为正向促进作用,且前者驱动力强于后者;居民消费水平提升是拉动用水量增长的主导因素,而居民消费结构优化升级和居民消费率上升均有效抑制了水资源的消耗,且前者更为显著;用水量的下降主要得益于产业技术进步,生活用水量的增长主要源于生活强度效应。进一步指出未来应合理控制我国人口规模和人口流动,加速居民消费结构的优化升级,注重强化产业技术创新,深挖农业节水潜力,提升居民消费率以实现既定经济规模下的相对节水。     

混合型基金绩效评估及驱动因素分析——基于DEA-Tobit模型

将随机选出的混合型基金作为研究样本,采用DEA-Tobit二阶段模型进行研究.首先利用数据包络模型对样本进行绩效评估,在此基础上,利用Tobit模型研究相关指标对于基金绩效的影响机制.结果表明,基金本身所面临的风险收益因素以及基金经理团队稳定性对于基金绩效均具显著影响.最后结合实证结果就提升中国基金绩效提出相关的建议.     

Changing land use intensity in Europe – Recent processes in selected case studies

In recent decades the intensification of agricultural production in many European countries has been one of the key components of land-use change. The impact of agricultural intensification varies according to national and local contexts and a greater understanding of the drivers of intensification will help to mitigate against its negative impacts and harness potential benefits. This paper analyses changes in land use intensity in six case studies in Europe. A total of 437 landowners were interviewed and their responses were analysed in relation to changes in land use intensity and agricultural production between 2001 and 2011. In the case studies in Western and Eastern Europe we observed stabilisation during the last decade, and no clear tendency of increase or decrease of land use intensity. The use of fertilizers and pesticides seems to have decreased in our cases in Western Europe, which is contrary to trends in Eastern Europe. Agricultural production remained stable in almost all cases, except for an increase in Austria and Romania which may indicate that the farming efficiency has increased. A statistical analysis showed a division between study areas in Romania and Austria (increasing land use intensity) versus those in the Netherlands, Denmark and Greece (decreasing). In the Mediterranean cases we observe a process where agriculture is becoming increasingly marginalised, at the same time as changes in function with regard to urbanisation and recreational land uses have taken place. Logistic regression highlighted the importance of farm size and farmer type in understanding changes in land use intensity. The dominant pattern of stabilisation which has occurred over the past 10 years may also partly be a result of effective EU and national environmental and agricultural policies, which are increasingly concerned with improving environmental conditions in rural areas.     

Total Factor Productivity and Energy Intensity: An Empirical Study of China’s Cement Industry

China is the largest cement producer and consumer in the world. The cement industry’s rapid growth has led to a large demand of energy. This study reviews China’s cement industry in terms of energy intensity and examines the effects of technological progress on energy intensity. It also discusses the feasibility of achieving China’s energy reduction targets. We employ the Granger causality test and find that the total factor productivity or technological progress causes the energy intensity of the cement industry. Impulse responses analysis also proves that in the long run the technological change contributes to the decline in energy intensity of cement production.     

山东省耕地利用集约度时空变化及政策启示

研究目的:通过分析1993-2014年山东省耕地利用集约度总体和各投入要素集约度的时空变化特征及影响因素,进而探讨耕地利用集约度与社会经济发展水平的协调程度,并提出相应政策措施,以提高山东省耕地集约利用水平,保障区域粮食安全。研究方法:能值分析、GIS空间分析、主成分分析。研究结果:(1)1993-2014年,山东省耕地利用集约度总体呈增长态势,而劳动集约度不断下降;资本集约度中,属于省工性投入的农业机械集约度呈现出显著的线性增长特征,属于增产性投入的化肥、农药和农膜集约度均呈先升后降的趋势。(2)全省耕地集约利用水平空间差异明显,总体上呈"东西高,南北低"的特点。(3)耕地利用集约度在一定程度上受社会经济发展水平的制约,两者存在着不协调现象。研究结论:1993-2014年,山东省耕地利用集约度不断上升的同时也存在明显的区域差异,不同区域应依据当地自然和社会经济条件,采取相应措施提高耕地集约利用水平。     

LIQUIDATION IN LIMIT ORDER BOOKS WITH CONTROLLED INTENSITY

We consider a framework for solving optimal liquidation problems in limit order books. In particular, order arrivals are modeled as a point process whose intensity depends on the liquidation price. We set up a stochastic control problem in which the goal is to maximize the expected revenue from liquidating the entire position held. We solve this optimal liquidation problem for power‐law and exponential‐decay order book models explicitly and discuss several extensions. We also consider the continuous selling (or fluid) limit when the trading units are ever smaller and the intensity is ever larger. This limit provides an analytical approximation to the value function and the optimal solution. Using techniques from viscosity solutions we show that the discrete state problem and its optimal solution converge to the corresponding quantities in the continuous selling limit uniformly on compacts.     

ARBITRAGE‐FREE BILATERAL COUNTERPARTY RISK VALUATION UNDER COLLATERALIZATION AND APPLICATION TO CREDIT DEFAULT SWAPS

We develop an arbitrage‐free valuation framework for bilateral counterparty risk, where collateral is included with possible rehypothecation. We show that the adjustment is given by the sum of two option payoff terms, where each term depends on the netted exposure, i.e., the difference between the on‐default exposure and the predefault collateral account. We then specialize our analysis to credit default swaps (CDS) as underlying portfolios, and construct a numerical scheme to evaluate the adjustment under a doubly stochastic default framework. In particular, we show that for CDS contracts a perfect collateralization cannot be achieved, even under continuous collateralization, if the reference entity’s and counterparty’s default times are dependent. The impact of rehypothecation, collateral margining frequency, and default correlation‐induced contagion is illustrated with numerical examples.     

可行能力视角下农户参与农地整理规划的意愿与影响检验——基于安徽寿县4个典型镇的实证分析

[目的]提升农户参与的意愿与探寻有效参与机制。[方法]文章以安徽省寿县4个典型镇的147户农户与4个项目为调查对象,从农户的可行能力视角出发,运用Logistic模型研究农户参与农地整理规划意愿的驱动因素,运用ArcGIS10.0的空间分析功能检验农户参与对规划的影响。[结果]非农业收入比例、农地整理政策了解度、排灌沟渠布局、田间道路密度及公众参与机制等5类因素有显著推动作用;对规划的影响表现在较大程度优化了规划方案,提高了农地生产率等,但耕作田块扩大效应不显著、排灌沟渠存在空间集聚现象、偏好生产路建设及轻视田间林网工程建设等弊端制约了农业规模化经营、忽视规划全局性与环境效应等。[结论]可通过强化农地整理政策宣传力度、完善引导农户式的公众参与机制及基于农户可行能力视角构建农地整理规划效果的衡量尺度以提升农户参与的意愿与探寻有效参与机制。