4篇
您的检索式：作者名="Erwin Beck"
|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | 全球大停电的经验教训显示文摘根据国际能源机构的预测,在未来20多年里,发展中国家和新兴国家的耗电量将增加220%,而工业化国家则仅增加37%。现有电力系统负荷的大幅度增加将产生瓶颈效应和可靠性问题。历年发生的欧美州大停电清楚地表明,相邻系统间的紧密电气耦合对于重负荷互联系统而言,可能存在无法控制的级联事故风险。介绍美加大停电和欧洲大停电事件,讨论大停电的经验教训。对避免环流、防止电压崩溃等解决大型电力系统稳定性问题的措施及“防火墙”的实施进行了说明。阐述涉及系统改善的高压直流输电(HVDC)和灵活交流输电(FACTS)技术的优点。 | Gǖnther Beck Dusan Povh Dietmar Retzmann Erwin Tehsch | 2007 | 中国电力2007，40，10： | 11 |
| 2 | H202 destruction by ascorbate-dependent systems from chloroplasts显示文摘 | Dieter Greden Erwin Beck | 1979 | BBA1979，546，： | 1 |
| 3 | Specific and unspecific responses of plants to cold and drought stress显示文摘 | Erwin H Beck Sebastian Fettig Claudia Knake Katja Hartig Tribikram Bhattarai | 2007 | Journal of Biosciences2007，，3： | 1 |
| 4 | Identification of characteristic plant co-occurrences in neotropical secondary montane forests显示文摘Aims Inferring environmental conditions from characteristic patterns of plant co-occurrences can be crucial for the development of conservation strategies concerning secondary neotropical forests.However,nomethodological agreement has been achieved so far regarding the identification and classification of characteristic groups of vascular plant species in the tropics.This study examines botanical and,in particular,statistical aspects to beconsidered in such analyses.Based on these,we propose a novel data-driven approach for the identification of characteristic plantco-oc currences in neotropical secondary mountain forests.Methods Floristic inventory data were gathered in secondary tropical mountain forests in Ecuador.Vegetation classification was performed by coupling locally adaptive isometric feature mapping,a non-linear ordination method and fuzzy-c-means clustering.This approach was designed for dealing with underlying non-linearities and uncertainties in the inventory data.Important Findings The results indicate that the applied non-linear mapping in combination with fuzzy classification of species occurrence allows an effective identification of characteristic groups of co-occurring species as fuzzy-defined clusters.The selected species indicated groups representing characteristic life-form distributions,as they correspond to various stages of forest regeneration.Combining the identified‘characteristic species groups’with meta-information derived from accompanying studies indicated that the clusters can also be related to habitat conditions.In conclusion,we identified species groups either characteristic of different stages of forest succession after clear-cutting or of impact by fire or a landslide.We expect that the proposed data-mining method will be useful for vegetation classification where no a priori knowledge is available. | Miguel D.Mahecha Alfredo Martı´nez Holger Lange Markus Reichstein Erwin Beck | 2009 | Journal of Plant Ecology2009，2，1： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员