北京市生态城市建设能力的机理与综合评价--基于城市化与生态化视角

基于城市化与生态化两大子系统,从人口与空间城市化、经济城市化、社会城市化、和生态环境水平、生态压力、生态抗逆能力六个层面,构建生态城市建设能力评价的指标体系,运用相关分析、回归分析和主成分分析等方法,对1991-2002年北京市生态城市建设能力机理进行了综合分析与评价。     

THE HISTORY OF SEXUALITY: AN ASSESSMENT OF THE STATE OF THE FIELD

In this concise volume, Jeffrey Weeks traces the development of the history of sexuality from its earliest days, more than a century ago, to the present. He identifies dominant themes and subject matter as well as analyzing and commenting upon some of the key theoretical frameworks that have driven this scholarly endeavor. He devotes special attention to LGBT history, to histories of gender, power, and sexuality, and to globalization and the transnational turn in historical writing. He gives attention to the tensions that have often existed between a community‐based activist history produced from within the LGBT community and the history produced within the academy. Finally, he considers the degree to which sexual history has been mainstreamed and the dangers and the value of that process.     

THERMOLUMINESCENCE DATING OF POTTERY: AN ASSESSMENT OF THE DOSE-RATE FROM RUBIDIUM

The naturally occurring radioisotope ⁸⁷Rb makes a small contribution to the total dose-rate. Assuming an average potassium:rubidium ratio of 200:1 the contribution is estimated at 2.9% of the B dose-rate From potassium. The effect will be negligible in quartz inclusion dating because of the strong attenuation of the B- emission from ⁸⁷Rb. In fine-grain dating the omission of the ⁸⁷Rb contribution will overestimate the age of a pottery sherd by not more than 2% and this is regarded as of minor importance when the total error in the technique is at least 15%.     

AN ASSESSMENT OF BACK-SCATTERED ELECTRON PETROGRAPHY AS A METHOD FOR DISTINGUISHING MEDITERRANEAN OBSIDIANS

The recent application by Burton and Krinsley (1987) of back-scattered electron (BSE) petrography to obsidians from sources located in the south-western United States established that this method can effectively resolve and characterize included micro-crystalline phases that have proven difficult to analyse by optical thin-section microscopy. In the first extension of their original study, we have examined, using BSE petrography, obsidians from island sources located in the Mediterranean, including sources known to have been exploited in prehistory. Because of the kinetic contrasts on their crystallization, these microcrystalline phases reflect the magmatic history of the obsidian, providing information about superheating, supercooling, sub-solidus processes, and other phenomena. This information is of significance for the chemical analysis of Mediterranean obsidians and also as the basis for a powerful alternative to existing non-destructive analytical methods for the sourcing of archaeological and art-historical obsidian.