Quantifying spatial supply-demand mismatches in ecosystem services provides insights for land-use planning

Global trends in land-use changes, including urbanization and abandonment of rural areas, have important repercussions for the supply and demand of ecosystem services (ES). In this study, we assessed and mapped the supply and demand of three ES (water provision, climate regulation, and outdoor recreation) along an urban-rural gradient in the Madrid region (Spain) from 1990 to 2012. We mapped ES supply, based on land use/land cover (LULC) data, using InVEST models and complementary methods, and ES demand, using population density and demand indicators. Then, we explored spatial supply-demand mismatches at a municipality spatial scale. Despite an increase in ES supply in some areas, a general increase in ES demand led to increasing dependence by the Madrid metropolitan area on outlying areas. We found that the number of municipalities that exhibited mismatches between the supply and demand in ES increased throughout the study period, due mainly to urban sprawl. Our results suggest the need for comprehensive land-use planning at the regional scale, taking into account that many ES flows reach beyond municipality boundaries. Finally, we discuss the utility of analyzing spatial mismatches in the supply and demand of ES for land-use planning and decision-making.     

广西承接产业转移问题研究

产业转移是一种全球共生的经济现象,有其内在的规律。随着我国改革开放的不断深入以及全球经济形势的变化,承接产业转移成为促进经济发展的重要途径。我国一些发达地区在承接产业转移的过程中积累了丰富的经验。广西在承接东部产业转移的过程中也取得了很大成效,但也面临严峻的形势和存在许多亟待解决的问题,应认清形势,借鉴发达地区经验,进一步采取措施,做好产业转移承接工作,促进广西经济又好又快发展。     

一种复合局部与非局部梯度的图像去噪变分模型

局部变分有效地增强图像的轮廓信息，但不可避免地模糊图像的细节并在平滑区域产生阶梯效应。非局部变分能有效重构图像的纹理信息，但同时会破坏图像的结构轮廓信息。考虑到局部与非局部变分的互补性，提出了一种基于图像局部梯度与非局部梯度的复合变分模型，并通过Bregman交替迭代极小化图像的局部梯度与非局部梯度的L1范数,使去噪后的图像在去除噪声的同时更好地保留图像的结构与细节信息。对比实验证明，提出的复合变分模型有效地利用了图像的局部变分与非局部变分的优点,在图像评价的主客观方面都表现出了更好的性能。     

综合物探方法在多金属矿找矿靶区优选中的应用

在大宝山外围白面石多金属矿找矿靶区开展了激电中梯剖面测量以及重、磁、CSAMT综合剖面工作。通过白面石这个有利测区进行物探勘察方法技术的综合应用,对靶区进一步优选,开展物探勘察技术方法适应性研究,摸索出高效,快速的多种物探方法优化组合,为更快地缩小南岭地区矿产靶区范围提供有效的方法。     

加工贸易梯度转移研究——基于“雁行理论”的视角

改革开放以来,中国加工贸易快速发展,但地区分布严重不均。由于中国中西部地区存在物流成本高、产业配套水平低、市场环境较差等问题,因此,应借鉴东亚国家和地区加工贸易梯度转移的经验,在"雁行理论"的指导下进行加工贸易梯度转移,以便形成更为合理而高效的"雁行"格局。     

特低渗透储层非线性渗流规律研究

室内试验研究表明,流体在低渗透多孔介质中渗流时表现出非线性特征。文章从非线性渗流的基本特征入手,评价了特低渗透储层的启动压力梯度,得出了储层流体可动油的变化规律,为下步开发调整提供了理论指导。     

梯度发展战略与沿海出口加工业转移问题研究

从劳动力成本、转移成本和制度成本等方面,考察了外来投资出口加工企业向内地转移的可能性,认为国家梯度发展战略,并不是要在中西部继续走外向型发展道路,吸收东部沿海地区部分要淘汰的出口加工业。中西部地区发展,应以内需为导向的产业发展模式。加快中西部发展,是要在招商引资过程中,超越东部沿海地区外向型经济发展模式,积极引进内向型企业,这才是梯度战略的真实内涵。     

A spatial portfolio theory of household location choice

Classical residential location choice models were constructed as uncertainty-free. Using the expected utility theorem, urban researchers have dealt with different types of uncertainties, such as uncertain income, uncertain housing price and uncertain transportation cost, etc. This paper, however, considers uncertain traveling frequencies in two-workplace setting, a novel theory on the emergence of a new centre between two existing CBDs can then be formulated. It can be regarded as a spatial portfolio theory as the theory predicts that household location choice would strike a balance between commuting cost savings (return) and variance of the savings (risk). Empirical evidence on the housing transaction price gradient changes in Hong Kong supports the theory.     

耦合Sylvester矩阵方程的梯度迭代算法

通过推广求解矩阵方程AX=b或AX+XB=C的递推迭代算法和基于递阶辩识原理的思想,给出了求解广义耦合矩阵方程的梯度迭代算法。并证明了迭代算法的收敛性。分析表明,若矩阵方程有唯一解,则对任意的初始值该算法给出的迭代解都能快速的收敛到其精确解。数值实例验证了该算法的有效性。     

我国城市商业在扩大消费中的地位与作用

本文认为,城市商业特别是零售业是我国城乡居民消费需求实现的主要途径,未来我国商业将以城市市场为主要发展空间。城市商业的创新与发展,需要明确定位,探索多样化的发展思路与途径。“十一五”期间,城市商业的发展思路应该是:第一,壮大龙头,培育增长极;第二,城市互动,扩大和深化城市之间的合作与协调发展;第三,因地制宜,探索中小城市及中西部地区城市商业加快发展的新途径;第四,梯度发展,促进城市商业形成新发展秩序与格局。