麇鹿传奇

1865年,法国传教士阿芒·戴维的隔墙一瞥, 使当年仅存于皇家猎苑的珍贵物种麇鹿,渐渐被世人所知. 2003年春天,一头幼鹿诞生在中国江苏大丰麇鹿国家自然保护区, 结束了地球1000多年以来没有野生麋鹿的历史.     

Opacifiers in Late Bronze Age glasses: the use of ToF-SIMS to identify raw ingredients and production techniques

Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is applied to the study of four samples of opaque glass of Late Bronze Age date. The technique is uniquely capable of identifying compositional heterogeneity at a sub-micron resolution within the crystalline opacifiers dispersed through homogeneous glass matrices. It is shown that this provides crucial information on the possible raw ingredients of the opacifying inclusions used, and has the potential for highlighting regional variations in the production technology involved in creating different colours of opaque glass.     

INTRODUCTION: PROCESSES OF CHANGE IN URBAN SYSTEMS*

ABSTRACT The twenty‐first century will be one of intensified urbanization, on a scale never before experienced. How do urban systems and individual cities change and develop? The social sciences have many different approaches to analyzing the economic, social, and spatial dimensions of urban change. We inventory some of these approaches and their implications for public policy toward cities, urban change, and economic development.     

Network Location and Policy‐Oriented Behavior: An Analysis of Two‐Mode Networks of Coauthored Documents Concerning Climate Change in the Great Lakes Region*,†

This study explores how a scientist's location in science‐based policy networks can affect her policy‐oriented behaviors. In particular, we hypothesize that those scientists who fill structural holes in their networks will be more likely than others to engage in policy‐oriented behaviors. The network data are defined by scientists' coauthorship on policy documents regarding climate change in the Great Lakes. We employ a two‐mode network analysis to identify clusters of scientists who coauthored similar documents, and relative to those clusters, we identify those who fill structural holes by bridging between clusters. We find that those scientists who bridged between clusters were more likely to engage in policy‐oriented behaviors of policy advocacy and advising than were others in the network. This is an example of a link between network location and policy‐oriented behavior indicative of the broader phenomenon of how individuals exert agency, given structural constraints.