论如何提高地面气象测报工作质量

文章根据地面气象测报工作现状,结合笔者多年测报工作经验,谈几点提高地面测报工作质量的体会。     

住宅工程现浇钢筋混凝土楼板裂缝的分析与防治

近年来,土木施工技术、施工工艺不断发展,建筑新材料广泛使用,混凝土制备、运输设备不断更新。随着钢筋混凝土现浇板在房屋建设中的大量推广和应用,住宅楼现浇楼板裂缝问题成为住宅用户的投诉焦点。文章从材料使用、施工过程等方面对住宅工程现浇钢筋混凝土楼板裂缝问题进行综合分析,并总结了裂缝的防治措施。     

Monitoring trends of technological changes based on the dynamic patent lattice: A modified formal concept analysis approach

The strategic importance of monitoring technological changes is highlighted given the ever faster pace and increasing complexity of technological innovation. In this respect, patent citation analysis has been the most frequently adopted tool among others. However, patent citation analysis is subject to certain drawbacks that stem from only consideration of citing-cited information and time lags between citing and cited patents. This study proposes a formal concept analysis (FCA)-based approach to developing a dynamic patent lattice that can analyze complex relations among patents and monitor trends of technological changes. The FCA is a mathematical tool for grouping objects with shared properties based on the lattice theory. The distinct strengths of FCA, vis-á-vis other methods, lie in structuring and displaying the relations among objects from a massive amount of data. For the purpose of technology monitoring, the FCA is modified to take into account time periods and changes of patent keywords. A patent context is first constructed with the aid of domain experts and text mining technique. Two types of dynamic patent lattices are then developed by executing the modified FCA algorithm. A case study of laser technology in lithography for semiconductor manufacturing shows that the suggested dynamic patent lattice has considerable advantages over conventional patent citation maps in terms of visualization and informative power.     

Context matters: How existing sectors and competing technologies affect the prospects of the Swiss Bio-SNG innovation system

Emerging technological fields are affected by developments in their broader context. This article proposes a differentiation of context structures as a crucial step in the analysis of technological innovation systems. A thorough context analysis, so the argument, is essential for understanding the pace and direction of technology development and the prospects of an emerging technological innovation system. Empirical insights are provided for Bio-SNG, a technology in an early stage of development. The article discusses the conditions under which actors from different sectors (forestry, wood industry, and energy supply) may play a role in the emerging field. It is shown that Bio-SNG is likely to become a victim of the recent boom in wood-to-energy technologies that has favored investments in more mature but technologically inferior alternatives. The case provides lessons for policy making as it highlights how effective support schemes might foster a lock-in into technologies that are readily available.     

Biofuel policies and the environment: Do climate benefits warrant increased production from biofuel feedstocks?

We examine whether climate benefits warrant policies promoting biofuel production from agricultural crops when other environmental impacts are accounted for. We develop a general economic-ecological modelling framework for integrated analysis of biofuel policies. An economic model of farmers' decision making is combined with a biophysical model predicting the effects of farming practices on crop yields and relevant environmental impacts. They include GHG emissions over the life cycle, nitrogen and phosphorus runoff, and the quality of wildlife habitats. We apply our model to crop production in Finland. We find that under current biofuel production technology the case for promotion of biofuels is not as evident as has been generally thought. Only reed canary grass for biodiesel is unambiguously desirable, whereas biodiesel from rape seed and ethanol production from wheat and barley cause in most cases negative net impacts on the environment. Suggested policies in the US and the EU tend to improve slightly the environmental performance of biofuel production.     

Using spatial microsimulation to account for demographic and spatial factors in environmental benefit transfer

This paper presents a simulation-based modelling approach for estimating total visitor numbers and amenity values for prospective non-priced open-access outdoor recreation sites. To begin, the geographic extent of the market for recreation at a policy site is estimated using data from a similar study site. The population residing within this geographic area is simulated using a spatial microsimulation model and GIS techniques and an individual-level ‘visitor arrival function’ is then transferred across this simulated population. This allows the latent demand for visits to the policy site by each simulated individual to be predicted and summed, providing an estimate of the total potential demand for recreation at the site. Combining this with an economic value measure of a visit provides an estimate of the potential amenity value of the policy site. The approach is applied to Moyode Wood, a small-scale forest in the West of Ireland, and estimates the potential total economic value of recreation at €0.4 million for the site. The research represents the first time that spatial microsimulation has been used in environmental benefit transfer and shows how it can be used to control for differences in demographic and spatial factors between study and policy sites. It also demonstrates how individual-level single-site travel cost models estimated using on-site survey data can be used to predict demand at alternative policy sites.     

No matter how it is measured, income declines with global warming

The contemporaneous relationship between temperature and income is important because it enables economists to estimate the economic impact of global warming without assuming a structural model. Until recently, empirical evidence generally suggests that there is a negative relationship between temperature and income, and, therefore, global warming has an adverse impact on economic activity. However, Nordhaus (2006) argues that the temperature-income relationship depends on how income is measured. We show in this paper that the results of Nordhaus (2006) may be due to an omitted-variable problem. Based on a well-motivated temperature-income model, we find that the relationship between temperature and income is not dependent on income measurement. Our regression results show that the adverse impact of an increase of 1 °C in temperature can be as much as a 3% decrease in total income for the G-7 nations. Therefore, our results suggest an aggressive climate mitigation policy.     

Environmental impacts of changes to healthier diets in Europe

Food consumption causes, together with mobility, shelter and the use of electrical products, most life cycle impacts of consumption. Meat and dairy are among the highest contributors to environmental impacts from food consumption. A healthier diet might have less environmental impacts. Using the E3IOT environmentally extended input output database developed in an EU study on Environmental Impacts of Products (EIPRO), this paper estimates the difference in impacts between the European status quo and three simulated diet baskets, i.e. a pattern according to universal dietary recommendations, the same pattern with reduced meat consumption, and a ‘Mediterranean’ pattern with reduced meat consumption. Production technologies, protein and energy intake were kept constant. Though this implies just moderate dietary shifts, impact reductions of up to 8% were possible in reduced meat scenarios. The slightly changed food costs do not lead to significant first order rebound effects. Second order rebounds were estimated by applying the CAPRI partial equilibrium model. This analysis showed that European meat production sector will most likely respond by higher exports to compensate for losses on the domestic meat market. Higher impact reductions probably would need more drastic diet changes.     

An integrated decision-support approach in prioritizing risks of non-indigenous species in the face of high uncertainty

When evaluating the risks of future invasions, we often have sparse information on the likelihood that a species will arrive, establish and spread in a new environment, and on the potential impacts should this occur. Conventional risk assessment, therefore, is limited in providing guidance in managing the risk of non-indigenous species (NIS). However, risk management decisions must be made facing these uncertainties to avoid high and irreversible impacts.We develop an integrated ecological economic modeling and deliberative multi-criteria evaluation (DMCE) approach to support group decision-making in risk prioritization, using an example of ten NIS that could potentially impact Australian plant industries. This innovative approach seeks to combine the advantages of dynamic modeling with the benefits of DMCE in assessing and communicating uncertainty. The model unveils the complexity of the socio-ecological system of biological invasion, with a scenario analysis designed to interactively communicate scientific uncertainty to decision-makers. The DMCE provides a structured approach to identifying stakeholders' key concerns in addressing economic, social, and environmental dimensions of NIS risk explicitly. Functioning as a platform for risk communication, the DMCE also offers an opportunity for diverse views to enter the decision-making process and for the negotiation of consensus consensuses.     

中国股票型基金业绩持续性实证研究

本文采用动量检验法和回归系数法,检验了存续时间超过24个月的中国股票型基金业绩是否存在持续性.结果发现,101只样本基金的业绩在6个月存在显著的持续性.在此基础上,本文从风险收益和基金管理人能力两个角度检验了基金业绩持续性的来源,结果发现,CAPM和“三因素模型”,以及考虑了基金投资风格的管理人选股能力、择时能力及投资风格持续收益,均不能解释中国股票型基金的业绩持续性.