Catalysis: new perspectives from surface science

One-sixth of the value of all goods manufactured in the United States involves catalytic processes. However, in spite of this dramatic economic impact, little is known about this broad subject at the molecular level. In the last two decades a variety of techniques have been developed for studying at the atomic level the structure, composition, and chemical bonding at surfaces. These techniques have been used to study adsorption and reaction on metal single crystals in an ultrahigh vacuum environment or to analyze catalysts before and after reaction. An important new development has been the coupling of an apparatus for the measurement of reaction kinetics at elevated pressures with an ultrahigh vacuum system for surface analysis. This approach has demonstrated that metal single crystals can be used to successfully model many important catalytic reactions and has established a direct link between the results of ultrahigh vacuum surface measurements and the chemistry that occurs under typical catalytic-processing conditions.     

自然保护区学当前应该解决的几个科学问题

自然保护区已成为一类特殊的土地利用类型,总面积约占国土面积的14%以上;其不仅具有保护野生动植物资源的功能,而且在维护国土生态安全中发挥着关键作用.我国自然保护区建设工程实施过程中,迫切需要解决的主要科学技术问题包括自然保护区体系规划和合理布局方案研究制定、分类经营管理系统建立、野生动植物资源本底调查和动态监测等.自然保护区学是新建立的二级学科.该文定义了自然保护区学的内涵,提出了主要研究领域和方向.指出了当前研究热点问题,如“生态岛屿”状态的自然保护区内野生动植物小种群恢复与调控、自然保护区最小面积确定、生物廊道的设计、规划设计中的功能区划、自然资本评估与经济管理等.     

非计算机专业程序设计语言教学实践与探索

根据非计算机专业程序设计语言的教学实践,总结了程序设计语言教学中普遍存在的若干问题,结合高校非计算机专业学生的知识结构特点和程序设计语言的特点,分析了问题的成因并提出了改进教学的几点建议。     

Mobility, embodiment, and scales: Filipino immigrant perspectives on local food

Local foodshed proponents in the United States seek to change the food system through campaigns to “buy local” and to rediscover “good food” in the local foodshed. Presumably, common sense dictates that the word “local” signifies spatial proximity to the consumer. For some populations, however, both the terms “local” and “local food” signify various different meanings. The local food definition generally used by scholars and activists alike as “geographically proximate food” is unhelpfully narrow. Localist rhetoric often does not incorporate the food choices and practices of immigrants, migrants, and refugees. In this paper, I report the various characterizations of local food among Filipino immigrants in San Diego, California: (1) geography-based local food; (2) (US) America-based local food; (3) community-based local food; and (4) immigrant identity-based local food. Local foodshed proponents should acknowledge those who have a starkly different definition of “local”—those who possess translocal subjectivities, for whom “local-ness” is both mobile and embodied. My study underscores how the movement of food—or its containment within a geographic space—cannot be viewed in isolation from the movement of people.     

高校非计算机专业程序设计语言教学实践与探索

根据非计算机专业程序设计语言的教学实践，总结了程序设计语言教学中普遍存在的若干问题，结合非计算机专业学生的知识结构特点和程序设计语言的特点，分析了问题的成因并提出了改进教学的几点建议。     

我国学术创新的多学科比较研究——基于图书馆学、情报学、文献学、信息学分布

以学术创新为关联点,对我国1989-2008年图书馆学、情报学、文献学和信息学学术"创新"论文进行分析和比较研究,从定量的角度,客观地反映学术创新的研究热点和发展趋势,为学科资源共享及学科联合建设,增加综合竞争实力提供客观参考依据。     

Metrology and the state: science, revenue, and commerce

"Natural measures of quantity, such as fathoms, cubits, inches, taken from the proportion of the human body, were once in use with every nation," taught Adam Smith in his lecture "Money as the measure of value and medium of exchange," delivered in 1763. "But by a little observation," he continued, "they found that one man's arm was longer or shorter than another's, and that one was not to be compared with the other; and therefore wise men who attended to these things would endeavour to fix upon some more accurate measure, that equal quantities might be of equal values. Their method became absolutely necessary when people came to deal in many commodities, and in great quantities of them." Smith's comments and the rationale underpinning them became increasingly urgent toward the end of the eighteenth century.     

Multi-university research teams: shifting impact, geography, and stratification in science

This paper demonstrates that teamwork in science increasingly spans university boundaries, a dramatic shift in knowledge production that generalizes across virtually all fields of science, engineering, and social science. Moreover, elite universities play a dominant role in this shift. By examining 4.2 million papers published over three decades, we found that multi-university collaborations (i) are the fastest growing type of authorship structure, (ii) produce the highest-impact papers when they include a top-tier university, and (iii) are increasingly stratified by in-group university rank. Despite the rising frequency of research that crosses university boundaries, the intensification of social stratification in multi-university collaborations suggests a concentration of the production of scientific knowledge in fewer rather than more centers of high-impact science.