大遗址保护与城市更新——以汉长安遗址区规划研究为例

以汉长安城规划研究为例，通过对汉长安城遗址特征、价值评估、现状建设的分析，探索汉长安城保护与城市更新的发展模式，并在此基础上对汉长安城遗址区提出总体发展构想。     

汉长安城遗址保护与开发利用的现状、问题及对策探讨

本文分析了汉长安城遗址保护区社会经济特征及社会经济发展与遗址保护的矛盾,提出了遗址保护区保护与开发利用的方向与对策。     

汉长安城城门遗址保护与展示方法初探

汉长安城是国务院公布的第一批全国重点文物保驴单位,是汉王朝的政治、经济、文化的中心.汉长安城在今西安市区西北约十公里处,周长25100米,全城总面积34.39平方千米.而汉长安城考古工作进行约有半个世纪,硕果丰厚.汉长安城遗址也将以遗址公园的模式进行整体保护与展示,本论文就是以汉长安城城门遗址为研究对象并探讨保护与展示方法的论文.     

汉长安城的历史形态演变与遗址区 村落保护

从城市形态学理论视角,探讨了汉长安城遗址区的历史形态演变,及其对遗址区村落的保护与再利用启示。随着2013年未央宫遗址公园的建设,遗址区原址的10个村落进行了整体搬迁。从城市历史保护的连续性、真实性与完整性角度来看,这种做法具有不少挑战。从汉长安城形态演变中最为突出的4个历史阶段,梳理了西汉以来汉长安城的城市建设、水系格局、道路系统以及村落布局等形态要素的演变过程,并通过信息叠加分析,探讨了遗址区村落与原址地形和水系格局等形态要素间的共生关系。最后从历史形态保护视角,指出了村落形态在汉长安城历史形态保护与传承中的重要意义。     

唐昭陵地貌景观与遗址分布空间意象初探

在系统分析昭陵陵园山顶、山脊、山谷、平原地貌景观和陵园建筑遗址与陪葬墓空间分布模式的基础上，从山体形象、风水空间格局、长安城空间特征三个方面论述了昭陵陵园的空间意象和“依山为陵”的历史文化意义。     

考古遗址公园建设中“真实性”保护展示 途径探讨——以隋唐洛阳城定鼎门遗址公园 规划为例

2019年3月，国家住房和城乡建设部与国家文物局 联合提出了对部分历史文化名城保护不利情况的批评，重点 强调了历史文化遗址保护的“真实性”要求。以隋唐洛阳城定 鼎门遗址公园规划设计为例，探讨考古遗址公园建设中大遗址 “真实性”保护与展示利用的途径。提出大遗址保护应坚持 “真实性、完整性及可逆性”的保护展示原则，以遗址片区 “最小干预”为规划理念，充分考虑遗址公园保护与开发的平 衡关系。在此基础上，形成了从考古资料中分析挖掘史料信 息，对遗址价值进行研究判定，从而构建遗址价值载体的展示 阐释体系，最后从文化遗产活化利用的角度，提升遗址公园社 会效益的大遗址“真实性”保护展示途径。     

区域生态环境建设战略的理论和实践探讨——以烟台市为例

本文运用景观生态规划、生态系统管理的基本原理与方法,从理论上探讨了如何基于景观格局总体特征构建区域生态环境建设战略。在此基础上,以烟台市为例,系统分析了该区域景观格局的总体框架、生态环境现状及其主要问题,并提出景观—区域尺度上烟台市生态环境建设的总体构架及对策。     

基于生态安全导向的县域建设用地优化配置——以临泽县为例

通过对区域生态、经济及社会等多方面要素差异的综合分析,以景观安全格局为导向,结合建设用地适宜性分区结果,运用GIS空间叠加技术及互斥性矩阵分类方法,将评价区域划分为具有不同空间开发强度的类型区,并提出各种类型区的空间发展方向和管制要求,以达到区域建设用地优化配置的目标。通过研究,提出了基于景观安全格局理念下的建设用地优化配置方法,从空间战略上实现经济开发与生态保护的双赢。     

试论文物遗址开发利用的经济可行性——以西安市大明宫御道广场建设为例

本文以唐大明宫遗址御道广场的的规划和建设为例,从文物遗址的特性出发,通过分析大明宫御道的保护现状和存在问题,提出大明宫御道广场的建设具有重要的现实和理论意义,并进一步对大明宫御道广场建设的可行性进行了系统的分析,指出文物遗址的保护和利用对区域经济和社会的发展、产业结构的调整、生态环境和城市的形象改善等均有重要的作用,为文物遗址的保护和利用提供了理论和现实依据。     

唐长安城城墙遗址的历史价值与保护探讨

唐长安城是中国乃至世界古代城市建设史上无以伦比的典范,城墙的遗址表明了唐长安城的范围和历史的沧桑,具有重要的历史价值.本文强调在西安城市开发建设中不要背离"千年长安城"的规划格局并探讨了遗址保护的办法.     

Forecasting the price of gold

This article seeks to evaluate the appropriateness of a variety of existing forecasting techniques (17 methods) at providing accurate and statistically significant forecasts for gold price. We report the results from the nine most competitive techniques. Special consideration is given to the ability of these techniques to provide forecasts which outperforms the random walk (RW) as we noticed that certain multivariate models (which included prices of silver, platinum, palladium and rhodium, besides gold) were also unable to outperform the RW in this case. Interestingly, the results show that none of the forecasting techniques are able to outperform the RW at horizons of 1 and 9 steps ahead, and on average, the exponential smoothing model is seen providing the best forecasts in terms of the lowest root mean squared error over the 24-month forecasting horizons. Moreover, we find that the univariate models used in this article are able to outperform the Bayesian autoregression and Bayesian vector autoregressive models, with exponential smoothing reporting statistically significant results in comparison with the former models, and classical autoregressive and the vector autoregressive models in most cases.     

Planned adaptation in risk regulation: An initial survey of US environmental, health, and safety regulation

In principle, we want regulatory programs to be based on current realities, as reflected for example in the best knowledge of relevant experts. That would imply that old rules now on the books should be consistent with today's knowledge base, not just what was known when a rule or standard was originally set. This paper reports on a survey of US programs, examining how often existing rules are actually updated in light of better knowledge, and identifies five programs that attempt to make policy routinely adaptive. These programs exhibit what we term Planned Adaptation: they both revise rules when relevant new knowledge appears, and take steps to produce such improved knowledge. While Planned Adaptation is rare, it is used in several nationally prominent programs, including air pollution, airplane safety, and drug safety. Planned Adaptation is a policy tool that deserves more attention.     

The greenhouse effect: Damages,costs and abatement

The buildup of so-called greenhouse gases in the atmosphere — CO₂ in particular-appears to be having an adverse impact on the global climate. This paper briefly reviews current expectations with regard to physical and biological effects, their potential costs to society, and likely costs of abatement. For a worst case scenario it is impossible to assess, in economic terms, the full range of possible non-linear synergistic effects. In the most favorable (although not necessarily likely) case (of slow-paced climate change), however, it seems likely that the impacts are within the affordable range, at least in the industrialized countries of the world. In the third world the notion of affordability is of doubtful relevance, making the problem of quantitative evaluation almost impossible. We tentatively assess the lower limit of quantifiable climate-induced damages at $30 to $35 per ton of CO₂ equivalent, worldwide, with the major damages being concentrated in regions most adversely affected by sea-level rise. The non-quantifiable environmental damages are also significant and should by no means be disregarded.The costs and benefits of (1) reducing CFC use and (2) reducing fossil fuel consumption, as a means of abatement, are considered in some detail. This strategy has remarkably high indirect benefits in terms of reduced air pollution damage and even direct cost savings to consumers. The indirect benefits of reduced air pollution and its associated health and environmental effects from fossil-fuel combustion in the industrialized countries range from $20 to $60 per ton of CO₂ eliminated. In addition, there is good evidence that modest (e.g. 25%) reductions in CO₂ emissions may be achievable by the U.S. (and, by implication, for other countries) by a combination of increased energy efficiency and restructuring that would permit simultaneous direct economic benefits (savings) to energy consumers of the order of $50 per ton of CO₂ saved. A higher level of overall emissions reduction — possibly approaching 50% — could probably be achieved, at little or not net cost, by taking advantage of these savings.We suggest the use of taxes on fossil fuel extraction (or a carbon tax) as a reasonable way of inducing the structural changes that would be required to achieve significant reduction in energy use and CO₂ emissions. To minimize the economic burden (and create a political constituency in support of the approach) we suggest the substitution of resource-based taxes in general for other types of taxes (on labor, income, real estate, or trade) that are now the main sources of government revenue. While it is conceded that it would be difficult to calculate the optimal tax on extractive resources, we do not think this is a necessary prerequisite to policy-making. In fact, we note that the existing tax system has never been optimized according to theoretical principles, and is far from optimal by any reasonable criteria.During the academic year 1989–90 Dr. Ayres was at the International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.During the summer of 1989 Mr. Walter was a member of the Young Scientists' Summer Program at IIASA.     

SCIENCE AND INDUSTRY: TRACING THE FLOW OF BASIC RESEARCH THROUGH MANUFACTURING AND TRADE

This paper describes flows of basic research through the US economy during the late 20th century. In addition, the paper studies the effect of the flows on scientific papers in industries and fields. This article differs from others in its use of measures of science rather than technology. Together, its results present a picture of the structure of basic research flows in a modern, science-intensive economy. Basic research flows are large within petrochemicals and drugs, and within software and communications. Flows of chemistry, physics, and engineering are common throughout all industries – biology and medicine are almost confined to petrochemicals and drugs; and computer science is nearly as restricted to software and communications. In general, basic research flows are more concentrated within scientific fields than within industries. Our findings concerning the production of scientific papers indicate that the effect of a 1% change in academic R&D spillovers significantly exceeds that of industrial spillovers. In addition, within-field effects exceed effects between-fields, while within- and between-industry effects are roughly equal. It follows that scientific fields limit basic research flows more than industries do, perhaps because large firms implicitly span a range of industries.     

Valuing Mangrove-Fishery Linkages – A Case Study of Campeche, Mexico

This paper explores the value of mangrove systems as a breeding and nursery habitat for off-shore fisheries, focusing on mangrove-shrimp production linkages in Campeche State, Mexico. We develop an open access fishery model to account explicitly for the effect of mangrove area on carrying capacity and thus production. From the long-run equilibrium conditions of the model we are able to establish the key parameters determining the comparative static effects of a change in mangrove area on this equilibrium. We then estimate empirically the effects of changes in mangrove area in the Laguna de Terminos on the production and value of shrimp harvests in Campeche over 1980–90. Our findings suggest that mangroves are an important and essential input into the Campeche shrimp fishery, but that the low levels of deforestation between 1980 and 1990 mean that the resulting losses to the shrimp fishery are still comparatively small. Over-exploitation of the fishery due to open access conditions remains the more pervasive threat, and without better management any long-run benefits of protecting mangrove habitat are likely to be dissipated.     

An Economic Analysis and Simulation of Woodfuel Management in the Sahel

This paper presents an economic framework and a computationalmethodology for assessing the evolution of woodfuel supply costsand the spatial distribution of biomass in a Sahelian woodlandsetting. Spatial data on standing stock and the costs oftransport to market are used to construct a supply curve for fuelto a fuel-consuming location. Given an exogenously specifieddemand, the model simulates, period by period, the extraction,regeneration, and transport of wood fuels. The model is appliedto evaluate the benefits and ecological impacts of scenarios forwoodland management around the city of N'Djamena, Chad.     

Evidence on the impact of R&D and ICT investments on innovation and productivity in Italian firms

Both research and development (R&D) and information and communication technology (ICT) investment have been identified as sources of relative innovation underperformance in Europe vis-à-vis the USA. In this article, we investigate the R&D and ICT investment at the firm level in an effort to assess their relative importance and to what extent they are complements or substitutes. We use data on a large unbalanced panel data sample of Italian manufacturing firms constructed from four consecutive waves of a survey of manufacturing firms, to estimate a version of the CDM model of R&D, innovation, and productivity [Crépon–Duguet–Mairesse 1998. Research, innovation and productivity: An econometric analysis at the firm level. Economics of Innovation and New Technology 7, no. 2: 115–58] that has been modified to include ICT investment and R&D as the two main inputs into innovation and productivity. We find that R&D and ICT are both strongly associated with innovation and productivity, with R&D being more important for innovation, and ICT investment being more important for productivity. For the median firm, rates of return to both investments are so high that they suggest considerably underinvestment in both these activities. We explore the possible complementarity between R&D and ICT in innovation and production, but find none, although we do find complementarity between R&D and worker skill in innovation.     

Zvi Griliches's contributions to the economics of technology and growth*

Zvi Griliches's contributions to the economics of technology and growth are identified. Included is a discussion of his contributions on: the determinants of differences in speed of adoption of innovations; the use of patents to measure technology; the private and social returns to R&D; and spillover effects from R&D. Griliches's own evaluation of his research contribution is compared to the evaluation of others in the field, using as evidence citation counts of his works collected from the online Web of Science. Griliches's most important contribution is his 1957 Econometrica hybrid corn paper that is a foundation of the economics of technological innovation. Remarkably, the trend in annual citations to the paper has continued to increase for over 40 years. Finally, we summarize Griliches's most recent views on the practice of economics and on the most important unanswered questions in the economics of technology and growth.     

新员工主动社会化行为与组织承诺关系研究——以社会资本为中介变量

为了探索新员工主动社会化行为影响组织承诺的过程,本文对来自企业的401个有效样本进行了实证分析。本研究运用层级回归的方法,控制了人口统计变量的影响后,发现员工的搜寻信息和搜寻绩效反馈行为对组织承诺有直接的正面影响,同时,通过员工社会资本对员工组织承诺产生了间接的正面影响。社会资本在员工搜寻信息和搜寻绩效反馈行为影响组织承诺的机制中起部分中介作用。员工的关系构建行为对组织承诺没有显著影响,但对员工社会资本存在显著的正面影响。