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R. M. STEVENS J. M. PECH M. R. GIBBERD R. R. WALKER P. R. NICHOLAS 《Australian Journal of Grape and Wine Research》2010,16(3):413-425
Background and Aims: The study investigated whether rootstocks can modify grapevine responses to reduced irrigation. Methods and Results: Drip-irrigated Shiraz vines on eight rootstocks were subjected to industry standard and 30% reduced irrigation regimes over four seasons. Reducing irrigation decreased pruning weights and yield, but did not consistently affect irrigation water use index (IWUI). It increased leaf Δ13C. Reduced irrigation and elevated vapour pressure deficit (VPD) were associated with decreases in leaf water potential (ψl), leaf stomatal conductance and assimilation rate. Reducing irrigation raised leaf transpiration efficiency, whereas elevated VPD lowered it. These effects of reduced irrigation were independent of rootstock. Vines grafted to 101-14 had a higher ψl and achieved the highest yield and IWUI. The yields of vines grafted to Ramsey, Schwarzmann and 140 Ruggeri were also high. Vines grafted to 101-14, Ramsey and 1103 Paulsen had the higher rates of leaf assimilation. Rootstock did not affect Δ13C. Conclusion: The gain in leaf transpiration efficiency caused by reducing irrigation was not associated with a gain in IWUI. Rootstocks 101-14, Ramsey, Schwarzmann and 140 Ruggeri achieved higher yields and IWUI under both standard and reduced irrigation regimes. Significance of the Study: Among grafted vines growing on saline soil but receiving non-saline irrigation water and subject to a 30% reduction in irrigation, the yield responses of vines grafted on rootstocks rated as having good drought tolerance were the same as those of vines grafted on rootstocks rated as having poor drought tolerance. 相似文献
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SUMMARY: Using thin-layer chromatography and gas-liquid chromatography the following substances were identified in banana pulp (Musa saplentum L.): Cycloartenol, cycloeucalenol, 24-methylene cycloartanol, campesterol, β-sitosterol and stigmasterol. The major triterpene was 24-methylene cycloartanol while β-sitosterol accounted for greater than 72% of the sterol fraction. 相似文献
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SARVAPALI D. RAMCHURN NICHOLAS R. JENNINGS CARLES SIERRA LLUIS GODO 《Applied Artificial Intelligence》2013,27(9-10):833-852
In open environments in which autonomous agents can break contracts, computational models of trust have an important role to play in determining who to interact with and how interactions unfold. To this end, we develop such a trust model, based on confidence and reputation, and show how it can be concretely applied, using fuzzy sets, to guide agents in evaluating past interactions and in establishing new contracts with one another. 相似文献
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A special enhancement algorithm is derived to colour separate ground-cover classes whose recorded wavelength distributions are similar but have significantly differing intensities. The special enhancement function is derived from considering the spectrum locus of a CIE 1931 (x,y) chromaticity diagram. By analogy with the relationship between the chromaticity co-ordinates and the channel radiance levels a function is derived that stretches the radiances to maximize the colour differences between such ground-cover classes. This Sinsusoidal Squeeze algorithm was applied to enhance the colour differentiation of Antarctic ice types as recorded by LANDSAT. A comparison between this special enhancement and the conventional colour composite results for Antarctic ice pack is presented. Field checks conducted during the 1980-81 Antarctic summer field season confirm our ability to delineate up to seven different types of ice by this technique. Additional applications of this special algorithm are believed to be forest class differentiation and bathymetric feature delineation. 相似文献
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SUMMARY— By means of thin-layer chromatography, gas-liquid chromatography and chemical analyses the following substances were identified in dried Iceberg lettuce ( Lactztca sativ L.): ceryl alcohol, β-sitosterol, stigmasterol, campesterol and the glycosides of the latter three sterols. An unidentified substance, probably a sterol, was detected by gas-liquid chromatography. A mixture of triterpenes identified as containing β-amyrin, ã-amyrin and Ψtaraxasterol was also found. 相似文献
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The late 1970s and early 1980s represent a difficult period for affirmative action programs in American cities. Given a new, conservative political environment symbolized by the re-election of Ronald Reagan and the advent of serious fiscal constraints facing many cities, is it reasonable to expect continuing progress toward representative workforces in municipal governments? This article investigates this question using data gathered from repeated surveys of over 250 municipal police departments in major U.S. cities over the period 1981 to 1984. Findings observed suggest that although minorities made sufficient gains in these years to constitute a firm foothold for future progress, women are likely to have a long and difficult road ahead with respect to their full incorporation into municipal law enforcement. 相似文献
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The potential utilization of expert systems in construction management has drawn considerable attention in recent years. Many prototype systems were developed and have been described in previous studies. None of these studies, however, has addressed the basis for the selection of an expert system building tool (ESBT), the most important component in developing such systems. This paper presents a set of criteria for such selection. The criteria is then applied to investigate nine commercially available ESBTs, including four microcomputer-based tools, for building a knowledge-based expert system for construction planning and control. The criteria, although developed for specific application, could be readily extend to cover other problem domians. 相似文献
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Abstract In addition to confounding mass-based wear measurements in serum-lubricated hip simulator experiments, fluid absorption by the acetabular cups may simultaneously modify the wear resistance of the ultra-high molecular weight polyethylene (UHMWPE) from which they are composed. To decouple the fluid absorption and wear processes enabling clearer investigation of this effect, absorption was first imposed during an initial stage where UHMWPE was exposed to pressurized (10 MPa) fluid. This was followed by a second stage, where resultant wear behavior was assessed by a multidirectional pin-on-flat technique that, though still providing a serum-lubricating environment, does not promote the simultaneous fluid absorption occurring in hip simulator testing. Both unirradiated and highly crosslinked UHMWPE were investigated, each with both bovine calf serum and water soaking exposures of duration to 129 days. The pressurized soaking of a highly crosslinked UHMWPE decreased its wear resistance, causing an increase in wear rate by approximately 50% during subsequent serum-lubricated multidirectional pin-on-flat sliding tests as compared to non-soaked material. The magnitude of this effect did not appear to depend on whether the soaking fluid was water or serum, nor did it appear to depend on soak time provided it was at least of a 14-day duration, during which more rapid transient fluid absorption occurs. Such soaking did not produce as pronounced an effect on unirradiated UHMWPE, as its lack of wear resistance likely causes the absorption-affected surface region to be removed within the earliest stages of sliding contact. 相似文献