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181.
Teak (Tectona grandis L.f.) is considered to be an extraordinarily durable building timber with a worldwide reputation. Its widespread use has
entailed the over-exploitation of natural forests and a large reduction in natural diversity. Fifteen microsatellite markers
were used to study the genetic variability and structure of 166 teak trees distributed over the whole natural area of teak.
Analysis showed that in the teak natural area there were four main centers of genetic variability. Two clusters were in India
and could be considered as main centers of genetic diversity in teak. The third cluster mainly consisting of populations in
Thailand and Laos was genetically very distinct from the Indian populations but presented only half as much allelic variability.
A fourth cluster from Central Laos showed even less genetic variability. The use of SSR markers for conservation of teak forest
diversity is discussed. 相似文献
182.
Rie Suzuki Yasuyuki Matsushita Takanori Imai Mariko Sakurai José Manoel Henriques de Jesus Salete Kiyoka Ozaki Zenesio Finger Kazuhiko Fukushima 《Journal of Wood Science》2008,54(2):174-178
The heartwood and sapwood characteristics of 11 Amazonian trees were investigated. Whereas 7 of the specimens had densities greater than 0.7 g/cm3, the heartwood density of ipê amarelo (Tabebuia serratifolia), maçaranduba (Manilkara huberi), cumaru-ferro (Dipteryx odorata), and guarita (Astronium lecointei) exceeded 1.0 g/cm3. Jatobá contained small amounts of Klason lignin and α-cellulose, and large amounts of holocellulose and alkali extract, suggesting that it has a high polysaccharide content that can be dissolved in an alkaline medium. The difference in the syringyl/guaiacyl (S/G) ratios of the samples before and after alkali extraction suggests that alkali extracts contain syringyl-type polyphenols. In all of the samples, the heart-wood methanol extracts were larger in volume than the sapwood methanol extracts, and the sapwood alkali extracts were larger in volume than the heartwood alkali extracts. The antioxidant activities of the methanol and alkali extracts were assayed by measuring the levels of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and super oxide dismutase (SOD)-like activity, respectively. The heart-wood methanol extract of jatobá (Hymenaea courbaril) exhibited the highest level of activity (EC50 = 44 mg/l), which exceeded that of α-tocopherol (EC50 = 48 mg/l), and the heartwood alkali extracts of jatobá and ipê amarelo had high SOD-like activity comparable with red wine. 相似文献
183.
Mafalda Figueiras Guilherme Kim Joo de Jesus Gregersen Lars‐Flemming Pedersen 《Aquaculture Research》2020,51(8):3274-3283
The recent development of recirculation aquaculture systems (RAS) potentially allows more sustainable and controlled rearing conditions. However, control of suspended microparticles and microalgae in RAS is challenging, as uncontrolled blooms of toxic algae or heterotrophic dinoflagellates can have catastrophic impacts on the production of fish. In this study, we tested the potential of protein skimmers to remove microalgae. In 100 L batch tests, protein skimmers were tested separately and in combination with ozone (O3), ultraviolet (UV) or hydrogen peroxide (H2O2). Three different and distinct microalgae cultures were tested with densities from 30,000 to 120,000 algae cells/ml in a triplicated experimental setup. Trial 1 included twelve 24‐hr replicated tests where protein skimmers with air or with two levels of ozone (low and high O3 exposure) were compared. The protein skimmer with air alone had a limited effect on the removal of microalgae compared to the untreated control algae tanks. When ozone and protein skimmers were combined, a clear additive effect was found, and all added microalgae were removed. Low O3 dosage and protein skimmers completely removed the algae cultures within 12 hr, while more than 95% of the algae were removed within 7 hr when a higher ozone dose was used. The second trial compared the removal capacity of protein skimmers in combination with UV, H2O2 and O3. These experiments showed no to limited additive effect of UV combined with protein skimming, but significantly increased removal efficiency (270% and 1,300%, respectively) was found when H2O2 and ozone were combined with a protein skimmer. The study showed an algae species‐specific response to a protein skimmer with ozonation and provided information on the transition from reactivity and consumption to accumulation of ozone‐produced oxidants. 相似文献
184.
Symbiotic supplementation on the hemato‐immunological parameters and survival of the hybrid surubim after challenge with Aeromonas hydrophila
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J.L.P. Mouriño F.N. Vieira A. Jatobá B.C. Silva G.V. Pereira G.F.A. Jesus T.T. Ushizima W.Q. Seiffert M.L. Martins 《Aquaculture Nutrition》2017,23(2):276-284
This study evaluated the effects of dietary supplementation with two symbiotics in the hybrid surubim (Pseudoplatystoma corruscans × P. reticulatum) prior to and after challenge with Aeromonas hydrophila. The fish were divided into unsupplemented fish, supplemented fish with Weissella cibaria and inulin, and supplemented fish with Lactobacillus plantarum and inulin. Twenty days after being fed symbiotics, the fish were sampled for immunological, haematological, and microbiological analysis pre‐challenge. After this period, they were challenged with Aeromonas hydrophila, and after 96 h the fish were sampled for blood collection and survival. Fish fed W. cibaria and inulin from the pre‐challenge showed the highest values of lysozyme activity. Fish fed L. plantarum and inulin presented a higher number of thrombocytes and granular leukocyte PAS+ than the other fish. After challenge, fish fed both symbiotics presented an increased red blood cells number. Fish fed L. plantarum and inulin showed an increased total leucocyte count (WBC), neutrophils, and monocytes number as well as total immunoglobulin. The W. cibaria‐ and inulin‐supplemented fish showed improved haematological and immunological parameters and reduced cumulative mortality after the challenge. 相似文献
185.
Lázaro Wender Oliveira de Jesus Chayrra Chehade Fabiano Gonçalves Costa Maria Inês Borella 《Fish physiology and biochemistry》2014,40(3):897-909
In this study, we describe for the first time the details of the pituitary gland morphogenesis and the ontogeny of adenohypophyseal cells of a South American Characiform species with great importance for Brazilian Aquaculture, Salminus brasiliensis (Characiformes, Characidae), from hatching to 25 days after hatching (dah), by histochemical and immunocytochemical methods. The pituitary placode was first detected at hatching (0 dah), and the pituitary anlage became more defined at 0.5 dah. The neurohypophysis (NH) development started at 3 dah, and the early formation of its stalk at 12.5 dah. An increase in adenohypophyseal and NH tissues was also observed, and in juveniles at 25 dah, the pituitary displayed similar morphology to that found in adults of this species, displaying the main features of the teleost pituitary. PRL cells were detected at 0.5 dah, together with ACTH and α-MSH cells, followed by GH and SL cells at 1.5 dah. β-FSH cells were detected at 25 dah, while β-LH cells at 5 dah. The pituitary development in this species comprises a dynamic process similar to other teleosts. Our findings in S. brasiliensis corroborate the heterogeneity in the ontogeny of adenohypophyseal cells in teleosts and suggest a role for adenohypophyseal hormones in the early development of this species. 相似文献
186.
Winfried Schröder Marcel Holy Roland Pesch Harry Harmens Ilia Ilyin Eiliv Steinnes Renate Alber Yuliya Aleksiayenak Oleg Blum Mahmut Coşkun Maria Dam Ludwig De Temmerman Marina Frolova Marina Frontasyeva Laura Gonzalez Miqueo Krystyna Grodzińska Zvonka Jeran Szymon Korzekwa Miodrag Krmar Eero Kubin Kestutis Kvietkus Sébastien Leblond Siiri Liiv Sigurður Magnússon Blanka Maňkovská Juha Piispanen Åke Rühling Jesus Santamaria Zdravko Spiric Ivan Suchara Lotti Thöni Viktor Urumov Lilyana Yurukova Harald G. Zechmeister 《Journal of Soils and Sediments》2010,10(8):1572-1584
Purpose
This study aimed at investigating correlations between heavy metal concentrations in mosses and modelled deposition values as well as other site-specific and regional characteristics to determine which factors primarily affect cadmium, lead and mercury concentrations in mosses. The resulting relationships could potentially be used to enhance the spatial resolution of heavy metal deposition maps across Europe.Materials and methods
Modelled heavy metal deposition data and data on the concentration of heavy metals in naturally growing mosses were integrated into a geographic information system and analysed by means of bivariate rank correlation analysis and multivariate decision trees. Modelled deposition data were validated annually with deposition measurements at up to 63 EMEP measurement stations within the European Monitoring and Evaluation Programme (EMEP), and mosses were collected at up to 7,000 sites at 5-year intervals between 1990 and 2005.Results and discussion
Moderate to high correlations were found between cadmium and lead concentrations in mosses and modelled atmospheric deposition of these metals: Spearman rank correlation coefficients were between 0.62 and 0.67, and 0.67 and 0.73 for cadmium and lead, respectively (p?<?0.001). Multivariate decision tree analyses showed that cadmium and lead concentrations in mosses were primarily determined by the atmospheric deposition of these metals, followed by emissions of the metals. Low to very low correlations were observed between mercury concentrations in mosses and modelled atmospheric deposition of mercury. According to the multivariate analyses, spatial variations of the mercury concentration in mosses was primarily associated with the sampled moss species and not with the modelled deposition, but regional differences in the atmospheric chemistry of mercury and corresponding interactions with the moss may also be involved.Conclusions
At least for cadmium and lead, concentrations in mosses are a valuable tool in determining and mapping the spatial variation in atmospheric deposition across Europe at a high spatial resolution. For mercury, more studies are needed to elucidate interactions of different chemical species with the moss. 相似文献187.
Olivier Couillerot Marie-Lara Bouffaud Ezékiel Baudoin Daniel Muller Jesus Caballero-Mellado 《Soil biology & biochemistry》2010,42(12):2298-2305
Azospirillum lipoferum CRT1 is a promising phytostimulatory PGPR for maize, whose effect on the plant is cell density-dependent. A nested PCR method is available for detection of the strain but does not allow quantification. The objective was to develop a real-time PCR method for quantification of A. lipoferum CRT1 in the rhizosphere of maize seedlings. Primers were designed based on a strain-specific RFLP marker, and their specificity was verified under qualitative and quantitative PCR conditions based on successful CRT1 amplification and absence of cross-reaction with genomic DNA from various rhizosphere strains. Real-time PCR conditions were then optimized using DNA from inoculated or non-inoculated maize rhizosphere samples. The detection limit was 60 fg DNA (corresponding to 19 cells) with pure cultures and 4 × 104 CFU equivalents g−1 lyophilized sample consisting of mixture of rhizosphere soil and roots. Inoculant quantification was effective down to 104 CFU equivalents g−1. Assessment of CRT1 rhizosphere levels in a field trial was in accordance with estimates from semi-quantitative PCR targeting another locus. This real-time PCR method, which is now available for direct rhizosphere monitoring of A. lipoferum CRT1 in greenhouse and field experiments, could be used as a reference for developing quantification tools for other Azospirillum inoculants. 相似文献
188.
189.
Escrivão RJ Webb EC Garcês AP Grimbeek RJ 《Tropical animal health and production》2012,44(7):1779-1782
Sixty multiparous Brahman-type cows were randomly selected in the early postpartum period and equally allocated into a calf removal group (RG) and a non-removal group (NRG). Calves from cows in the RG were removed for 48 h prior to the breeding season and returned afterwards, whereas in the NRG, calves remained with their dams until weaning. Weaning weights were corrected to 205?days. Conception rates (CRs) were 76?% for RG and 55?% for NRG but did not differ (p?>?0.05). CR was correlated with calving to breeding interval and body condition score at the onset of the breeding season. Product-limit survival curves vs breeding to conception interval differed significantly (p?0.05) between treatment groups. It was estimated with 95?% certainty that 50?% of the cows in the RG will conceive within the first 12?days of the breeding season, while 39?days were required for cows in the NRG. Weaning weights were 135.2?±?22?kg for RG and 135.5?±?19?kg for NRG. It was concluded that 48-hour calf removal prior to breeding season increased the number of cows that conceive early in the breeding season and enhanced conception rates but did not affect calf weaning weights of Bos indicus cattle in extensive production systems. 相似文献
190.