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利用直接的积分估计,研究非线性复微分方程(f~(k))~(n_k)+A_(k-1)(z)(f~(k-1))~(n_(k-1))+…+A_1(z)(f′)~(n_1)+A_0(z)f=Ak(z)解的函数空间属性,刻画了方程的解析解,以及它们的导数属于H∞ω空间时系数需要满足的条件.改善及推广了已有的相关结果. 相似文献
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主要研究分数次Hardy算子和Lipschitz函数生成的交换子在Lipschitz空间上的端点估计.分数次积分算子的方法不适用于分数次Hardy算子,将给出新的方法,同时也将考虑分数次极大算子的交换子的结果. 相似文献
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Urban green areas, due to their high plant diversity, can be supportive as floral resources (nectar and/or pollen) to wild and managed pollinating insects. This research aims towards understanding the contribution of ornamental ground cover perennials as a food source for urban pollinators. We compare floral phenology and abundance, nectar and pollen production, and insect visitation to flowers of Geranium macrorrhizum, G. platypetalum and G. sanguineum, planted in the botanical garden of Lublin, SE Poland. The investigation revealed that the studied hardy geraniums exhibit many features valuable for pollinators, including large floral display (G. macrorrhizum and G. platypetalum), extended flowering period (G. sanguineum) and ample nectar and pollen reward (G. macrorrhizum). They can supply urban pollinators with a high quality food during spring and early summer time, i.e. the period of high food demand by many bee species. Moreover, hardy geraniums might be valuable plants for urban beekeeping as they are eagerly visited by honeybees. The investigated ground cover plants could therefore be considered in future city plantings. 相似文献
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李丹衡 《湖南农业大学学报(自然科学版)》2006,33(6)
首先引入了一类由Littlewood-Paley算子和BMO函数构成的交换子,然后利用原子分解的方法证明了该交换子在加权H1空间上的有界性. 相似文献
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Inoculation of growing media with plant growth promoting rhizobacteria (PGPR) has a number of potential benefits for the production of ornamental plants. Certain rhizobacteria synthesise the enzyme ACC deaminase, which cleaves ACC, the precursor of the plant hormone ethylene. Bacterial metabolism is now known to lead to a reduction in [ACC] in the plant transpiration stream and bacteria are hypothesised to act on ACC exuded from roots. This in turn reduces the ethylene generated in plants growing in growing media inoculated with these bacteria. Here we tested if applications of the ACC deaminase containing rhizobacteria Variovorax paradoxus5C–2could be of benefit to ornamental growers by reducing ethylene generation in stressed plants. Ethylene is produced at levels that are inhibitory to growth and development under a number of abiotic stresses. The propagation and production of hardy ornamentals is deleteriously affected by abiotic stresses that involve ethylene signalling, including drought and physical wounding. Inoculation of growing media with V. paradoxus 5C-2 lowered ethylene emission from mature leaves of Cytisus × praecox experiencing drought stress. In addition, bacterial inoculation of the growing media resulted in significantly reduced abscission of the mature leaves under drought treatment. Beneficial effects of inoculation where also found in the wounding response of Fargesia murielae following divisional propagation and late season senescence in Aquilegia × hybrida in response to drought stress. Together these results demonstrate that V. paradoxus5C–2has real potential for use on ornamental nurseries in situations where plant stresses are unavoidable. 相似文献
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晚熟耐贮梨新品种-新苹梨选育 总被引:1,自引:0,他引:1
新苹梨是一优良实生品种,属白梨系统。优质、晚熟、耐贮、抗逆性强。平均单果重357 g,果形指数0.99,酥脆多汁,可溶性 固形物7.85%,总糖8.46%,总酸0.56%,酸甜味浓,果实发育期150d,属晚熟品种。果实常温下可贮至翌年5月份,贮后风味更佳; 抗寒性与苹果梨相似,对梨黑星病和黑斑病有较强抗性;结果习性与苹果梨相近。可在苹果梨种植区域栽培。 相似文献
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杨湘豫 《湖南农业大学学报(自然科学版)》2006,33(4)
首先引入了一类由Marcinkiwicz算子和BMO函数构成的多线性交换子,然后利用原子分解的方法证明了该多线性交换子在Hardy型空间中的加权有界性. 相似文献
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Ikuo Kataoka Toru Mizugami Jin Gook Kim Kenji Beppu Tetsuo Fukuda Shuji Sugahara Koji Tanaka Hirofumi Satoh Kazuhiro Tozawa 《Scientia Horticulturae》2010
Survey on the wild genetic resources of hardy kiwifruit (Actinidia arguta) in Japan was conducted to determine the ploidy variation and its geographic distribution. Among the 127 wild plants collected from different geographic locations, 15 plants were diploid, 87 were tetraploid, and 22 were hexaploid. Additionally, 2 plants were heptaploid and one plant was octaploid. The tetraploid plants were distributed all over the country, whereas the diploid and hexaploid plants were geographically localized, in the warm Pacific hill areas of the south western part and in the deep-snow region of the mid-northern part of Honshu, respectively. The diploid plants could be clearly distinguished from other plants with ploidy variation by the morphological characteristics of the leaf and fruit. Hexaploid plants showed a relatively larger L/D ratio of the leaf blade, a greenish petiole, and pubescence on the petiole and lower leaf vein, whereas the tetraploid plants exhibited a reddish petiole and callose hairs on the vein of the lower leaf surface. Fruit shape of the tetraploid plants varied largely, from round to ellipsoidal, whereas that of the hexaploid plants was mostly ellipsoidal. These results indicate that the hexaploid plants of A. arguta as well as the diploid and tetraploid ones, naturally grow in a certain size of population in the restricted region of Japan. 相似文献