全文获取类型
收费全文 | 182篇 |
免费 | 10篇 |
出版年
2013年 | 9篇 |
2012年 | 3篇 |
2010年 | 4篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 3篇 |
2004年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 3篇 |
1966年 | 2篇 |
1963年 | 1篇 |
1959年 | 3篇 |
1958年 | 10篇 |
1957年 | 6篇 |
1956年 | 5篇 |
1955年 | 5篇 |
1954年 | 4篇 |
1953年 | 2篇 |
1952年 | 3篇 |
1951年 | 3篇 |
1950年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
1912年 | 1篇 |
排序方式: 共有192条查询结果,搜索用时 218 毫秒
131.
132.
133.
134.
135.
136.
We present aspects and data for a tool‐driven database for marketing and product development, which are publicly accessible. The objective is to create a method whereby knowledge of concepts and products can be archived using overviews of a specific product category. The first phase of the database comprises systematic analysis of product concepts, which contain elements dealing both with features and emotions. The concept phase provides an idea about responses to statements about product features, along with responses to emotional elements and brands. The second phase comprises an analysis of the competitive frame of products, even before systematic product development is initiated. This second phase identifies expected and thus reasonable ranges of product‐sensory features, levels of acceptance of typical products, relations between liking and sensory attributes and segmentation of sensory preferences. Together, the two phases provide a guide to product developers new in a category, archive current knowledge and provide a sourcebook for marketers and developers alike, which is accessible using research tools. The two phases allow product development to become more scientific, more based on common experience rather than individual expertise and thus more efficient, without compromising corporate knowledge of specific ingredients, processes or business opportunities. 相似文献
137.
Management of plant invasions mediated by frugivore interactions 总被引:8,自引:1,他引:7
138.
Molecular evidence for the hybrid origin of a new endemic species of Stylosanthes Sw. (Fabaceae) from the Mexican Yucatán Peninsula 总被引:1,自引:1,他引:0
JACQUELINE VANDER STAPPEN USANA GAMA LOPEZ PATRICIA DAVILA GUIDO VOLCKAERT 《Botanical journal of the Linnean Society. Linnean Society of London》2002,140(1):1-13
Stylosanthes aff. calcicola is a formally undescribed tetraploid species from the Mexican Yucatán Peninsula, showing morphological similarities to the diploid species S. calcicola , but distinct in a number of characters. We used uni- and biparentally inherited molecular markers to infer the hybrid origin of this species in relation to known diploid species of Stylosanthes . Molecular characterization was based on length and/or DNA sequence variation of nuclear sequence-tagged site (STS) markers, the internal transcribed spacer (ITS) region of nuclear rDNA and the trnL intron of chloroplast DNA (cpDNA). Stylosanthes aff. calcicola contains a distinct cpDNA haplotype and nuclear DNA fragment, with closest relationship to the diploid species S. calcicola . In contrast, the DNA sequences of two nuclear loci reveal a closer relationship to the diploid species S. angustifolia , S. hispida , S. humilis , S. leiocarpa and S. viscosa . The majority of the STS markers showed additivity of PCR fragments in S. aff. calcicola , representing the combination of two genetically different genomes. We postulate that S. aff. calcicola is a distinct species of allotetraploid origin that appears to have originated once from hybridization between two divergent genomes, of which the maternal and paternal parent are closely related to, or derived from, a member of the lineages represented by S. calcicola and S. viscosa , respectively. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 140 , 1–13. 相似文献
139.
140.