全文获取类型
收费全文 | 125篇 |
免费 | 0篇 |
出版年
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 10篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1962年 | 3篇 |
1959年 | 1篇 |
1958年 | 2篇 |
1957年 | 2篇 |
排序方式: 共有125条查询结果,搜索用时 15 毫秒
81.
MULTIPERFORATE SEPTA IN LICHENS 总被引:1,自引:0,他引:1
CLIFFORD M. WETMORE 《The New phytologist》1973,72(3):535-538
82.
Gels incorporating carbendazim and triadimefon were prepared from sodium alginate, a xanthan gum or an esterified alginic acid and evaluated as wound treatments on apple and plum trees. Fungicide movement and persistence were similar with sodium alginate and xanthan gels but movement was reduced and persistence increased with the esterified material. Callus tissue formation was not inhibited by any formulation. Adding acid to fungicides to form salts had little effect on fungicide movement or persistence and caused unacceptable phytotoxicity. Thiophanate-methyl or thiabendazole were not superior to carbendazim, nor imazalil to triadimefon, for protection against Nectria galligena and Chondroster-eum purpureum respectively. Sealants containing octhilinone, carbendazim plus captan, or mercuric oxide quickly established sufficient fungicide in the wood to eradicate N. galligena but possibly insufficient to protect adequately against C. purpureum. Gel formulations are valid alternatives to sealants as fresh wound pathogen treatments but fungicide persistence is insufficient for them to be recommended for treatment against mature wound pathogens. 相似文献
83.
CLIFFORD GEERTZ 《American anthropologist》2004,106(2):420-420
Engineers of Happy Land: Technology and Nationalism in. Colony. Rudolph Mrázek. Princeton: Princeton University Press, 2002. 368 pp. 相似文献
84.
EVIDENCE THAT SALIVARY PROTEINS ARE INVOLVED IN ASTRINGENCY 总被引:1,自引:0,他引:1
Proteins in saliva samples taken from twelve subjects immediately before and immediately after tasting astringent solutions were analyzed by high performance liquid chromatography. Although considerable variation in both the qualitative and quantitative protein pattern was observed among individuals, three peaks appeared to be common to the majority of the chromatograms. The tasting of the astringent solutions resulted in detectable changes in the protein profile of the saliva samples, observed in all the chromatograms examined, and attributed to the interactions of the saliva proteins with the astringent phenolic compounds. The appearance of a major peak at 8 min after the tasting of the astringent compounds common to most of the saliva chromatograms was attributed to the formation of soluble protein-phenol complexes. 相似文献
85.
CLIFFORD A. CUFFEY ALBERT J. ROBB JOHN T. LEMBCKE ROGER J. CUFFEY 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1995,28(2):139-153
The in-life and post-mortem orientations of the Lower Devonian brachiopod Meristella atoka from the Haragan Formation (Lower Devonian; south-central Oklahoma) are inferred from the distribution of epizoic bryozoans and the orientations of base plates of epizoic corals. Three bryozoans, Cyphotrypa corrugata, Fistuliporella maynardi and Leioclema pulchellum, and one coral, Favosites conicus, are considered. Most zoaria that contact the commissure terminate at the commissurc, and a few zoaria terminate at growth lines. This suggests that the bryozoans were primarily life associates of Meristella atoka. Collectively, these three bryozoan species most extensively encrusted marginal sectors of the brachial valve and are very rare on the posteromedian sector (the umbo) of the pedicle valve. This distributional pattern indicates that the preferred living orientation of Meristella atoka was umbo-down (posteromedian sector of the pedicle valve resting on or buried in the substratum) with the commissure steeply inclined to the sediment water interface. Most coralla of Favosites conicus that contacted the commissure encrusted over the commissure. This indicates that Favosites conicus either preferentially encrusted Meristella atoka post-mortem or colonized living brachiopods but subsequently caused them to die. Furthermore, Favosites conicus most extensively encrusted anterior sectors of the brachial valve, especially the fold. The lateral and anterior orientations of the commissure with respect to the base plates (holothecae) of Favosites conicus indicates that the brachiopods were oriented approximately horizontal with respect to the base plates. This suggests that the preferred post-mortem orientation of Meristella atoka was resting nearly horizontally on the substratum. These data and interpretations confirm previously inferred in-life orientations of Meristella atoka and are consistent with post-mortem orientations hypothesized for elongate-oval athyrid brachiopods. □Brachiopoda, Athyridacea, Meristella atoka , palaeoecology, autecology, epizoans, bryozoans, corals, sedimentology, Lower Devonian, North America, Oklahoma. 相似文献
86.
Twelve bowers of Archbold's Bowerbird Archboldia papuensis in the Tari Gap, Southern Highlands, Papua New Guinea, are described. Incomplete courtship displays at four bowers were observed directly and videotaped, and 13 courtship displays culminating in copulation at five bowers were videotaped automatically. Bowers and male advertisement and courtship vocalizations and visual displays are described. Vocalizations included the mimicry of numerous sympatric bird species, calls like those of other bowerbird genera found elsewhere and inanimate sounds of the habitat. Courtships involved two phases. In the first, the male repeatedly chased the female while moving low, close to the surface of the display court. In the second phase, the male prostrated himself below the female and the yellow crest of adult males was presented to females as the male shook and repeatedly raised and lowered his head. Contrary to a previous report, the courtship display of the male Archbold's Bowerbird was assertive and the low position of the male appeared to function in threat reduction. 相似文献
87.
Regression and time series model selection in small samples 总被引:65,自引:0,他引:65
88.
I.J. WRIGHT H. T. CLIFFORD R. KIDSON † M. L. REED B. L. RICE M. WESTOBY 《Biological journal of the Linnean Society. Linnean Society of London》2000,69(4):521-547
Seedling traits have been described across 1744 species of Australian plants. Six traits were coded as binary alternatives: (1) phanerocotyly vs cryptocotyiy; (2) first leaf scale‐like vs leaf‐like; (3) first leaf single vs paired; (4) cotyledons hairy vs. glabrous; (5) hypocotyl hairy vs glabrous, and (6) embryo green vs non‐green at maturity. Seed volume was calculated from measurements of seed dimensions. Three approaches were used in analysing the data: (1) the taxonomic distribution of binary character states was described; (2) the strength of bivariate character associations was quantified at species level (‘cross‐species' correlations and regressions); (3) the data were arrayed on a phylogenetic tree in order to analyse by ‘phylogenetic regression’ for correlated evolutionary shifts in trait pairs. All die traits appeared evolutionarily malleable. For example, while cryptocotyiy was the minority condition (22% of species), it occurred in many different taxa (124 genera, 40 families, 24 orders) with high levels of polymorphy (16%, 25% and 42% for genera, families and orders). Similarly, the less common attribute states for first leaf type, hypocotyl texture, cotyledon texture and embryo colour occurred in species from right across die dicotyledon phylogeny, as did independent evolutionary divergences in each of mese characters. These patterns indicate that debate over which conditions are primitive and which are advanced will not have any general answer, only an answer for a specific branch‐step in die phylogenetic tree. In nearly all cases, correlated‐divergence analyses showed the same patterns as cross‐species analyses. The strongest associations were between seed volume and cryptocotyiy, seed volume and scale‐like first leaf, and seed volume and presence of green embryo. In addition, cryptocotyiy and scale‐like first leaf, and cotyledon and hypocotyl type, were strongly associated in bom correlated‐divergence and cross‐species analyses. Interpretation of results was mosdy presented wim respect to seed size, a trait which we consider to be pivotal in a species' seedling establishment strategy. All possible pairwise combinations ofbinary seedling traits were found in our study species. Taken togedier, the various lines of evidence presented here suggest that the traits have assorted more or less independendy of each odier and provide no evidence of functional groups based an mese attributes. Thus, the several existing seedling typologies should be regarded as classifications of convenience rather than as reflecting fundamental types. 相似文献
89.
CLIFFORD N. DAHM JAMES R. CLEVERLY JULIA E. ALLRED COONROD JAMES R. THIBAULT DIANNE E. MCDONNELL & DAVID J. GILROY 《Freshwater Biology》2002,47(4):831-843
1. Evapotranspiration (ET) is a major source of water depletion from riverine systems in arid and semiarid climates. Water budgets have produced estimates of total depletions from riparian vegetation ET for a 320‐km reach of the Middle Rio Grande, New Mexico, U.S.A., that have ranged from 20 to 50% of total depletions from the river. 2. Tower‐based micrometeorological measurements of riparian zone ET throughout the growing season using three‐dimensional eddy covariance provided high quality estimates of ET at the stand scale. 3. A dense stand of salt cedar (111–122 cm year–1) and a mature cottonwood (Populus deltoides ssp. wislizenia Eckenwelder) stand with an extensive understory of salt cedar (Tamaria ramosissima Ledeb) and Russian olive (Eleagnus angustifolia L.) (123 cm year–1) had the highest rates of annual ET. A mature cottonwood stand with a closed canopy had intermediate rates of ET (98 cm year–1). A less dense salt cedar stand had the lowest rates of ET (74–76 cm year–1). 4. Summer leaf area index (LAI) measurements within the four stands were positively correlated with daily ET rates. LAI measurements throughout the growing season coupled to riparian vegetation classification is a promising method for improving riverine corridor estimates of total annual riparian zone ET along a reach of river. 5. Combining recent estimates of the extent of riparian vegetation along the 320 km length of the Middle Rio Grande, from Landsat 7 imagery with annual growing season measurements of ET at the four riparian stands yields a first‐order riverine corridor estimate of total riparian zone ET of 150–250 × 106 m3 year–1. This is approximately 20–33% of total estimated depletions along this reach of river. 相似文献
90.