布雷顿森林体系与美国霸权     

何岚 《扬州教育学院学报》2004,22(2):39-44

战后美国的超级大国地位奠定了其作为布雷顿森林体系的主要设计师地位,美国得以在这一体系中贯彻其门户开放型新殖民主义的全球扩张战略。另一方面,布雷顿森林体系也是经济全球化趋势与国家垄断资本主义发展的产物,美国因此成为牵引全球化的火车头。美国主导之下的布雷顿森林体系进一步加强了美国的经济、政治霸主地位。  相似文献   

贵州野钟黑叶猴自然保护区种子植物区系研究   总被引：2，自引：0，他引：2  

左经会  林长松 《六盘水师范高等专科学校学报》2006,18(3):21-29

野钟黑叶猴自然保护区属市级自然保护区,以保护国家一级保护动物黑叶猴及其栖息环境为主要保护对象。据统计有种子植物132科371属551种。科级区系成分中,热带性质的科占66.04%,温带性质的科占33.96%;属的区系分析结果有13个分布区类型19个变型。热带分布属共171属,占总属数的51.81%,温带分布属共计158属,占总属数的47.88%。表明野钟黑叶猴自然保护区种子植物区系的亚热带性质。植物区系起源古老,古老区系成分较多,分布有白垩纪和第三纪的古老成分。本区内适钙植物较多,在本区石灰岩植物群落中占据着显赫地位。  相似文献   

雷州半岛南部近40万年以来的古植被与古生态——田洋湖钻孔孢粉数值分析   总被引：2，自引：0，他引：2  

郑卓  雷作淇 《中山大学学报论丛》1992,(1)

雷州半岛火山湖盆地第四系沉积的孢粉化石较完整地记录了近40万年以来的植被历史。本文用数值分析的方法探讨了田洋钻孔孢粉植物群的演变规律和古生态特征。根据有序样品最优分割的结果共综合成1个全新世孢粉带和7个更新世孢粉带(含14个亚带)。并利用R型聚类分析、对应分析探讨了各类建群植物的相互依存关系及其生态群特征。  相似文献   

循环林──森林资源良性循环的经营模式     

杨礼旦 《资源科学》1994,(2)

本文从探讨森林资源良性循环的概念和基本规律出发，提出了生态经济力与生态经济关系相适应是森林资源良性循环的基本规律。进而在分析常规林业的森林经营模式的弊端基础上，并根据森林资源良性循环的基本规律提出了循环林是森林资源良性循环的经营模式，并对循环林的类型、调整方法和经营要点作了探讨。  相似文献   

武夷冻茶霉菌菌相分析及优势菌ITSrDNA鉴定     

王梅英  陈慧斌  陈绍军 《莆田学院学报》2011,18(5):55-58

为研究武夷冻茶霉菌的分布情况,采用镜相分析和PCR(polymerase chain reaction)技术对霉菌进行菌相分析及优势菌种鉴定。结果表明,冻茶中主要菌属有曲霉属、毛霉属、根霉属和青霉属,其中青霉属为优势菌属;对随机分离纯化的青霉进行ITSrDNA鉴定,鉴定结果为壳青霉(Penicillium.crustosum Thom)。分析结果可为微生物污染途径分析以及改进冻茶的冷藏工艺条件提供理论依据。  相似文献   

Differential effects of norm-referenced and self-referenced feedback on performance expectancies,attributions, and motivation     

Wendy McColskey  Mark R. Leary 《Contemporary educational psychology》1985,10(3):275-284

When feedback is provided to students in a norm-referenced manner that compares the individual's performance to that of others, people who perform poorly tend to attribute their failures to lack of ability, expect to perform poorly in the future, and demonstrate decreased motivation on subsequent tasks. The present study examined the hypothesis that the deleterious effects of failure might be attenuated when failure is expressed in self-referenced terms—relative to the individual's known level of ability as assessed by other measures. In this study, subjects received feedback indicating that they did well or poorly on an anagram test, and this feedback was described as either norm-referenced (comparing the individual's performance to that of others) or as self-referenced (comparing performance to other measures of the individual's ability). As predicted, compared to norm-referenced failure, self referenced feedback resulted in higher expectancies regarding future performance and increased attributions to effort. Contrary to expectations, attributions to ability were not affected. The implications of the results for the structure of academic feedback are discussed.  相似文献   

基于FCM-PFS与PSO-RF的隐性知识外显案例适配研究     

张建华  杨俊晓 《科技管理研究》2022,(18)

对隐性知识外显案例实施有效适配,于知识应用乃至创新、实现乃至增值知识资源的价值,具有重要意义。本文深入研究了隐性知识外显案例适配机理。首先,采用毕达哥拉斯模糊集对知识属性值进行处理,建立知识表达系统;接着,运用K-Means算法对FCM聚类算法进行改进,压缩匹配空间、提升案例匹配效率;而后,基于PFS相关系数求解知识供需间的视图相似度,从而获得适配案例集。在此基础上,构建随机森林适配模型,并采用粒子群算法对其优化,以确保适配效果。与传统算法的对比实验验证了本文算法的比较优势。  相似文献   

The perception,management and performance of risk amongst Forest School educators     

Mark Connolly  Chantelle Haughton 《British Journal of Sociology of Education》2017,38(2):105-124

This article investigates how risk perception amongst teachers within an outdoor educational initiative, Forest School, both shape and are shaped by their understandings of childhood, pedagogy and their own professional identity. Drawing on a social constructionist perspective in theorising risk and childhood, the article argues that contemporary, hyper-sensitised concerns regarding children’s vulnerability emanate from both fears of the modern world, and the proclivity towards over-protection which these fears precipitate. Rather than treating this hyper-sensitivity as irrational or paranoid, the paper draws on socio-cultural theories and qualitative methods to interrogate how risk is perceived, managed and performed by teachers within an initiative which aims to reintroduce risk into children’s lives. The research found that while these teachers’ motivations to participate in Forest School were derived from a desire to expose children to formative risk-taking in the outdoors, the hegemonic cultural and institutional risk aversion which they were attempting to counter, aligned with their contested occupational identity, created tensions in how they managed and performed risk which militated against the full realisation of a Forest School pedagogy.  相似文献   

中国生态系统研究网络台站森林分布图编制规范及其制图的探讨     

邓坤枚 《资源科学》1997,19(1):61-66

本文阐述了研制“中国生态系统研究网络台站森林分布图编制范围”的重要意义与途径，同时，以鼎湖山站为例，依据“规范”对图例系统和森林分类  相似文献   

林业重点工程对农民收入流动的影响研究   总被引：2，自引：0，他引：2  

刘璨  林海燕 《中国软科学》2011,(1)

1998年以来,中国先后启动了天然林保护工程、退耕还林工程、京津风沙源治理工程等六项林业重点工程,每项林业重点工程采取了补贴、限制或者禁止林木商业采伐、禁止利用等多项政策。采用15个案例县的1995-2006年3096个样本数据分析林业重点工程对农民收入流动和收入长期不平等的影响,采用计量经济学分析方法,计量每个林业重点工程对农民收入流动的影响。研究结果显示:1)样本农户的收入流动总体很低;2)六项林业重点工程对样本农户收入流动表现出不同的影响。京津风沙源治理工程、退耕还林工程和防护林工程的实施在不同程度上促进了样本农户收入流动;天然林保护工程、野生动植物保护与自然保护区工程和重点地区速生丰产林基地建设工程对样本农户收入流动没有显著的影响;产生这些格局的原因在于林业重点工程的政策及其区域分布不同所致。  相似文献