在炼钢生产中如何降低石墨电极消耗

石墨电极消耗率是电炉炼钢生产的一个重要技术经济指标。近年来我厂1.5t电弧炉炼钢生产中,石墨电极消耗率呈现上升趋势。针对这一问题,我们实施现场攻关,发现电极折断消耗是石墨电极消耗大的主要原因。通过对电弧炉设备大修、改善炼钢环境、规范炉前操作行为,有效地解决了炼钢生产中电极折断消耗高的问题,使石墨电极消耗率从18.7kg/t降低到8.4kg/t,且取得了良好的技术效果和经济效益。     

Non-renewable resources in the long run

We model a competitive economy in which production is dependent on labor and a non-renewable resource, the stock of which is inhomogeneous. We solve the model analytically and show how—in infinite time—the economy moves away from an initial balanced growth path (b.g.p.) and towards a mature b.g.p. The characteristics of the initial b.g.p. match historical observations of slowly declining resource price and consumption growth tracking global product. The mature b.g.p. depends on the nature of the stock; the more steeply cross-sectional area declines with depth, the faster the rate of price increase. We show how the theoretical model may be adapted and parameterized to explain and predict the evolution of markets for specific resources, applying the model in two cases, copper and petroleum.     

浅谈丘陵地区市政排水管道的设计思路

本文主要探讨丘陵地区市政排水管道的设计思路,着重分析了丘陵地区排水系统的特点及相应的工程设计方案,确保丘陵地区市政排水管道建设具有可行性。     

Tuition fees and social segregation: lessons from a natural experiment at the University of Paris 9-Dauphine

Using a natural experiment, a sharp rise in tuition fees in some of the programmes at the University of Paris 9-Dauphine, we study the impact of tuition fees on students’ pathways, and outcomes. We apply an optimal matching method to the national database of students’ registrations (SISE) to define a typology of pathways. We then use a nonordered multinomial logit model to evaluate the impact of the rise in tuition fees on the types of pathways selected by the university. We show that there is a significant impact on these pathways. The increase in tuition fees reduces geographic and social mobility, thereby accentuating the phenomena of social segregation. Furthermore, contrary to what some of the studies assert, the rise does not appear to encourage greater effort: we find no impact on the graduation success rate.     

我国中部地区创新方法推广应用现状与对策研究——以湖北省为例

本文以湖北省为例研究我国中部地区创新方法推广应用现状，在分析总结湖北省创新方法工作主要经验和现有问题基础上，从政策导向、示范推广、市场运营、基础研究 4 个方面提出针对性建设建议，以期为中部地区的创新方法推广应用工作提供政策参考。     

电子商务背景下欠发达地区发展现代物流的对策与路径

从欠发达地区的物流现状入手,接着分析其存在的物流问题和产生原因,然后针对物流与电子商务的关系提出解决问题的对策。     

论我国西部区域间经济发展格局的变动

西部大开发的10年中,西部各地区都取得了巨大的发展成就,但彼此间的发展进度并不一致,导致了经济发展格局的变动。经过数据分析发现,西部各区域间发展差距有扩大的趋势,并且经济发展重心也有较大变化。认真分析这一变化,对于因地制宜的制定区域发展政策,促进区域协调发展具有重要指导意义。     

长江三角洲经济区发展战略探究——借鉴欧洲莱茵河流域经济发展的经验

长江三角洲地区是我国经济发展的先导区域,其发展成功与否决定着能否实现中华民族的复兴。本文通过对欧洲莱茵河流域和长江三角洲地区经济发展的对比分析,提出了若干长江三角洲经济区的发展战略。     

The Role of Human Capital,Market Potential and Natural Amenities in Understanding Spatial Wage Disparities in Chile

Abstract

This paper presents an empirical framework for analysing spatial wage inequality in Chile. Chile is primarily characterized by two stylized facts: the high spatial concentration around the metropolitan area and the key role of natural resources in the country. The paper considers both elements in a competition between NEG (new economic geography) and a theory based on natural resource endowment, with both theories incorporating human capital via a multilevel analysis. The results show the poor performance of NEG for Chile and indicate that natural resources are the principal cause of spatial wage variability in Chile.

RÉSUMÉ La présente communication illustre un cadre d'analyse empirique de l'inégalité spatiale entre les salaires, au Chili. Le Chili est caractérisé principalement par les deux faits stylisés suivants : une concentration spatiale élevée autour de la zone métropolitaine, et le rôle essentiel que jouent les ressources naturelles dans ce pays. Cette communication se penche sur ces deux éléments dans le cadre d'une compétition entre deux théories : d'une part la nouvelle géographie économique (« NEG »), de l'autre une théorie fondée sur la dotation en ressources naturelles, ces deux théories incorporant le capital humain par le biais d'une analyse à multiples niveaux. Les résultats démontrent les mauvais résultats de NEG pour le Chili, et indiquent que les ressources naturelles sont la principale cause de la variabilité spatiale des salaires au Chili.

EXTRACTO Este estudio presenta un marco empírico para analizar la desigualdad espacial de los salarios en Chile. Chile se caracteriza principalmente por dos hechos estilizados: la alta concentración espacial alrededor del área metropolitana y la función clave de los recursos naturales del país. El estudio considera ambos elementos en una competición entre la NEG (Nueva Geografía Económica) y una teoría basada en el legado de recursos naturales, donde ambas teorías incorporan el capital humano a través de un análisis de múltiples niveles. Los resultados muestran un bajo rendimiento de la NEG en relación con Chile e indican que los recursos naturales son la causa principal de la variabilidad espacial de los salarios en Chile.

摘要: 本文提出了一种分析智利区域工资不均的经验框架。智利主要有两大特点: 大城市地区高度空间聚集和农村地区自然资源作用巨大。本文在对NEG (新经济地理学) 和基于自然资源储藏量的理论进行比较时, 考虑了这两个因素, 同时还通过多层次分析纳入了人力资源因素。结果显示智利NEG性能很差, 表明智利区域工资差异的主要原因是自然资源。     

Metropolitan land-change science: A framework for research on tropical and subtropical forest recovery in city-regions

In efforts to promote transitions to sustainability in city-regions, government and nongovernment actors throughout the world are devising comprehensive sustainability strategies and implementing a variety of environmental policies. Social actors in many city-regions view forest stewardship as an important element of this integrated approach. Generally, urban sustainability goals are guided by the principles of ecological integrity, environmental quality, social equity, social inclusion, and social justice. In other words, sustainable urban development should foster a good quality of life for all by providing equitable access to adequate economic opportunity, housing, education, public services, ecosystem services, and environmental amenities. Governance structures should pursue these goals democratically with legitimacy, transparency, and accountability. Effective sustainability planning and management depend on the reliability of land-use monitoring and modeling approaches. They also require field-based, qualitative empirical research to understand the complex social dynamics that are invisible from space. The aim of this paper is to encourage international, cross-disciplinary dialogue on the conceptual, theoretical, methodological, and practical groundwork necessary to effectively carry out metropolitan land-change science, particularly for rapidly expanding small- and medium-sized cities in developing countries. I begin by presenting the paper's central conceptual and theoretical framework. Next, I explore existing analytical and methodological approaches to the study of land-use dynamics in metropolitan regions. After a brief discussion of specific opportunities and challenges for collaborative, interdisciplinary research in support of metropolitan land-change science, I conclude by proposing a four-part agenda for coordinated investigation of tropical and subtropical forest recovery in city-regions worldwide.