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31.
Fourteen triterpene saponins (1-14) have been isolated from the roots of Medicago hybrida and their structures elucidated by FAB-MS and NMR analysis. Two of them are new compounds and were identified as hederagenin 3-O-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (7) and oleanolic acid 3-O-[beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl]-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranoside] (14). Seven saponins being mono- and bidesmosides of hederagenin (1, 5, 6, 9), one bidesmoside of bayogenin (2), and two bidesmosides of 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid (11) and oleanolic acid (13) are known compounds but not previously reported as saponin constituents of Medicago, whereas five other saponins, being mono- and bidesmosides of medicagenic acid (3, 4, 8, 10, 12), and one monodesmoside of hederagenin (8) have been previously isolated from other Medicago species. The presence of 2beta,3beta-dihydroxyolean-12-en-23-al-28-oic acid might represent an interesting intermediate in the biosynthesis of these substances. 相似文献
32.
Eutrophication of woodland ecosystems and disappearance of acidophilous species have often been observed in central and western Europe over recent decades. Considerable increase in air-borne nitrogen and sulphur has been invoked as responsible for these processes in most studies. Historic data indicate that for hundreds of years man removed litter and fodder from many woodlands in these areas. As a result, woodland soils became poorer and more acid than they were originally. Cessation of the removal of materials may resulted in soil enrichment and eutrophication of many woods. This hypothesis was tested in a 16-year litter removal experiment in an acidophilous mixed oak-pine wood in southern Poland. It was found that litter removal resulted in substantial impoverishment of soil. After 16 years soil of the litter removal plots contained significantly less P, Mg and Ca, and had a lower cation exchange capacity (CEC) in the epihumus subhorizon, and less Ca and a lower CEC in the humus and lessivage horizons than soil in the control plots. Vascular plant species and bryophytes colonized the litter removal plots much more frequently. Within 16 years species richness increased in the field layer of these plots, but abundance of dominant species and character of vegetation remained unchanged, while vegetation of the control plots changed from acidophilous to neutrophilous. Disappearance in the control plots of vascular plants species and mosses common in mixed woodlands was caused by thick litter layer which impeded seed germination and seedling development, and by competition of dominant species. The results obtained suggest that acidophilous vegetation in the field layer of the study wood was associated with material removal by man over a long time, and its eutrophication largely resulted from the cessation of traditional methods of management. 相似文献
33.
Zdanowicz Marta Mudryk Zbigniew Jan Perliński Piotr 《Veterinary research communications》2020,44(1):9-18
Veterinary Research Communications - Abundance and antibiotic resistance of bacteria of the genus Aeromonas isolated from the water of three carp ponds were studied. The number of those bacteria... 相似文献
34.
Niczyporuk JS Samorek-Salamonowicz E Kozdruń W Mizak Z 《Acta veterinaria Hungarica》2011,59(3):405-408
The aim of the study was to attempt the detection of West Nile virus (WNV) in wild birds in Poland. Forty-eight species of 1912 wild birds were used for the investigations. The birds were derived from various locations in Poland from early spring till late autumn of the years 2009-2011. The brain samples were homogenised and cellular RNA was isolated. Two methods (RT-PCR and nested RT-PCR) were used. The presence of WNV RNA was not detected in the samples examined. Additionally, a short analysis of the epizootiological situation regarding the presence of WNV in Poland is presented. 相似文献
35.
Jolanta Floryszak-Wieczorek Zbigniew Górski Magdalena Arasimowicz-Jelonek 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):249-258
Each living cell of a plant produces photons in certain conditions. Under normal physiological conditions, cell photon emission
is stationary and minimal. Disturbance in the oxidative homeostasis by biotic stress is manifested by increased ‘biophoton’
production. Such biophoton responses of plants may be used as an integral indicator of the degree of oxidative homeostasis
misbalance. Our results demonstrate that biophoton generation has been much higher in a resistant potato variety than in a
susceptible one till 10 h after Phytophthora infestans inoculation. In contrast, ultra-weak luminescence from detached susceptible potato and moderately resistant pelargonium leaves
increased from 1–4 to 4–5 days after inoculation with Phytophthora infestans or Botrytis cinerea, respectively. Pre-treatment of susceptible potato leaves with a defence inducer, arachidonic acid, resulted in a transient
burst of light in response to P. infestans lasting for 30–45 h post inoculation (hpi). This study presents the potential adaptation of functional imaging of ultra-weak
luminescence to monitor time-dependent free radical processes during disease development and its application to draw conclusions
on plant resistance to pathogens of different lifestyle. Moreover, it has been shown that imaging of temporal biophoton generation
from potato leaves treated with arachidonic acid might be a helpful marker in mapping oxidative changes leading to systemic
acquired resistance (SAR). 相似文献
36.
Robert Klewicki Dorota Konopacka Małgorzata Uczciwek Zbigniew Irzyniec Ewelina Piasecka Catherine Bonazzi 《The Journal of Horticultural Science and Biotechnology》2013,88(6):75-79
SummaryThe aim of our work was to measure sorption isotherms on freeze-dried and convectively-dried fruits (apple cv. Idared; sour cherry cv. English Morello; blackcurrant cv. Tiben), previously osmotically dehydrated in fructo-oligosaccharide solution, or concentrated apple juice. Isotherms were fitted using the Guggenheim-Anderson-de Boer Model. In none of the cases studied was isotherm non-continuity in the vicinity of the initial value of aw observed. All isotherms, classified as type III, demonstrated an increase in the equilibrium water content, along with an increase in water activity. A higher water content was observed in lyophilised material compared to material dried by convection. The water content in the monolayer (100 g?1 dry matter) ranged from 12.0 g for dried apple, to 17.0 g for dried sour cherry. These values can be considered as optimal in order to ensure safe storage conditions. The dried fruits should therefore be kept in a water activity range of 0.45 – 0.54 for lyophilised, and 0.46 – 0.63 for convectively-dried material. 相似文献
37.
Zbigniew Draczyński Maciej Boguń Stanisław Rabiej Teresa Mikołajczyk Grzegorz Szparaga Paulina Król 《Fibers and Polymers》2013,14(7):1107-1117
An investigation was made of the effect of basic spinning process parameters on the structure and properties of butyric-acetate copolymer of chitin (BOC) fibres. It was found that, considering the resulting tenacity of 20.3 cN/tex simultaneously with high water sorption and retention properties, it is favourable for the BOC fibre spinning process to be carried out with 1 % HAp or TCP nanoadditive. Furthermore, when 3 % of the HAp or TCP nanoadditive is incorporated into the BOC fibre material, no significant changes in the crystal structure occur compared with fibres without the nanoadditives, formed in similar conditions. Analysis of the porous structure and the properties of the surface of BOC fibres with HAp or TCP nanoadditive shows that the parameters are favourable for their medical application. 相似文献
38.
Serum concentrations of allergen‐specific IgE in horses with equine recurrent airway obstruction and healthy controls assessed by ELISA
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39.
Zbigniew Kaczkowski Piotr Frankiewicz Aleksander Gralczyk 《Fisheries Management and Ecology》2019,26(3):187-199
The Pilica River has warmed at a rate of 0.06°C per year since 1969, threatening the ecological services provided by the Sulejów Reservoir. Gillnet sampling revealed that the reservoir is inhabited by a cyprinid‐dominated fish assemblage with roach, Rutilus rutilus (L.) (42% of the total biomass), the dominant species. However, the interest of the anglers was primarily focused on common bream, Abramis brama (L.) (almost 65% of the catch), as revealed by the catch statistics (2004–2014). No direct evidence was found that the temperature increase had an influence on the recreational fishery or fish assemblage structure. On the other hand, changes in the fish assemblage that were reflected in angler catch composition were observed. A decrease in the catch of common bream in gillnets was accompanied by a shift in angler choices towards roach and other fish species. The sustainability of recreational fisheries is more likely to be influenced by changes in the economic status of society, water quality (toxic cyanobacteria blooms) and water management practices in Poland. The question arises about which species will dominate in the impoundment in the future if the warming trend continues and common carp, Cyprinus carpio L., stocking is maintained. 相似文献
40.
Z. Zwierzykowski E. Zwierzykowska A. Slusarkiewicz-Jarzina A. Ponitka 《Euphytica》1999,105(3):191-195
Anther culture was used to generate progeny from pentaploid F1 hybrids of Festuca arundinacea (2n = 6x = 42) with Lolium multiflorum
(2n = 4x = 28). Of 6360 anthers cultured, 676 green and 3460 albino plantlets were regenerated. Large differences in the anther
culture response were observed among the F1 hybrids with the regeneration efficiency ranging from 0 to 28.8 green plants per
100 anthers cultured. All regenerants were less vigorous than the F1 hybrids and considerable morphological variation was
present in such characters as plant height, leaf length and width, and the type and length of inflorescences. Among 295 plants
which flowered during the first growing season only 38 were male fertile with pollen stainability ranging from 7.7% to 84.7%.
Chromosome numbers in 170 analyzed regenerants ranged from 14 to 42 and fell into three groups: 14 to 21, 28, and 30 to 42.
The experiment demonstrated that generation of large populations of androgenic progeny was feasible.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献