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51.
52.
Yusuke TABATA Daisuke TOGO Masayuki KITAGAWA Kazato OISHI Hajime KUMAGAI Shinichi KUME Hiroyuki HIROOKA 《Animal Science Journal》2009,80(4):475-485
The objective of this study was to quantify nitrogen (N), phosphorus (P) and potassium (K) utilization and their cycling in a beef-forage production system. A survey was conducted at the Kyoto University experimental farm in Kyoto Prefecture, Japan, and included 9.5 ha of meadow and about 160 head of beef cattle. Forages cultivated on the meadow were ensiled and offered to breeding cows. The whole farm was regarded as a beef-forage production system. The system consisted of three components: animals, manure and soil/crop. Nutrient inputs, flows through the soil-plant-animal pathway and outputs were quantified for 2 periods for the whole farm. Nutrient utilization was evaluated by nutrient balances, utilization efficiencies (ratio of nutrient export to nutrient input) and cycling index. The average nutrient balances of N, P and K for the whole farm (kg/year/ha) were 435.7, 136.3, and 262.8, and the average nutrient utilization efficiencies were 0.08, 0.06, and 0.01, respectively. The characteristics of nutrient balances and utilization efficiencies for each component differed among the nutrients. The average cycling indices for N, P and K were 0.19, 0.17 and 0.49, respectively. This study illustrates the importance of internal nutrient cycling for improving nutrient utilization in beef production systems. 相似文献
53.
Ozaki S Oki N Suzuki S Kitamura S 《Journal of agricultural and food chemistry》2010,58(22):11593-11599
An arabinogalactan-protein (WSSP-AGP) was isolated from the tuberous cortex of the white-skinned sweet potato (WSSP; Ipomoea batatas L.). It consists of 95% (w/w) carbohydrate and 5% (w/w) protein with high contents of hydroxyproline, alanine, and serine. Its sugar composition is α-L-Rha:α-L-Ara:β-D-Gal:β-D-GlcA in a molar ratio of 1.0:4.1:7.6:1.3. Its weight-average molecular weight was estimated to be 126,800 g/mol by high-performance size exclusion chromatography coupled with multiangle laser light scattering. Structural analysis indicated that WSSP-AGP is a (1→3)-β-D-galactan highly branched at O-6 with (1→6)-β-D-galactan, in which the branched chains are substituted at the O-3 position with α-L-Araf-(1→ and α-L-Araf-(1→5)-α-L-Araf-(1→ and at the O-6 position typically with α-L-Rhap-(1→4)-β-D-GlcAp-(1→ as terminating groups. Continuous administration of WSSP-AGP to KKAy mice significantly lowered fasting plasma glucose levels. This indicates that WSSP-AGP plays an important role in the hypoglycemic effects of WSSP. 相似文献
54.
Jeffrey P. Vanderpham Shinichi Nakagawa Gerard P. Closs 《Ecology of Freshwater Fish》2013,22(4):596-606
Species termed ‘habitat‐generalists’ are able to survive across a wide range of habitats, potentially enabled by the plastic behaviours and morphologies of individuals. This study aimed to compare habitat‐related adaptive specialisation in habitat‐generalists and specialists, by comparing feeding abilities of fish under varied hydrodynamic conditions. We compared the proportion of prey consumed by a New Zealand fluvial habitat‐specialist, the redfin bully, to a closely related habitat‐generalist found in fluvial and lacustrine habitats, the common bully, over a 6‐h period in either still or turbulent aquaria. We tested for intraspecific habitat‐specific adaptations by comparing feeding of common bullies from habitats with different hydrodynamic conditions. Within common bullies, previous research has documented a pattern of more lateral‐line system oculoscapular canal pores in fluvial habitats compared to lacustrine ones. By testing for a relationship between total pores and feeding success, we also aimed to identify the adaptive value of an increase in pores in turbulence. We identified decreased feeding (i.e., proportion of prey consumed) by both species in turbulence, but less so for redfin bullies. There was no clear indication of adaptation to habitat type by common bullies, with high variability in feeding by fish from all locations. We also found no statistical relationship between feeding and total oculoscapular canal pores. The results of this study suggest specialised adaptations of a habitat‐specialist to turbulent environments. The variability in feeding activity of common bullies also suggests the importance of behavioural plasticity in the survival of a habitat‐generalist across a wide range of conditions. 相似文献
55.
Summary A new method for determining ploidy levels in cytochimeral plants was developed by examining the maximum number of nucleoli per cell. Colchicine-treated plants of Allium wakegi Araki and A. fistulosum L., which have different ploidy levels in the first (LI), the second (LII), and the third (LIII) germ layer, were used together with untreated 2-2-2 plants of the same species. Nucleoli in guard cells for LI and in mesophyll cells for LII were stained in a 50% AgNO3 aqueous solution at 55° C for three hours under dark, humid conditions. In both species the ploidy levels of LI determined by the maximum number of nucleoli per guard cell accorded well with those determined by guard cell length. In A. fistulosum the ploidy levels of LII determined by the maximum number of nucleoli per mesophyll cell clearly agreed with those determined by pollen size. This method provided more precise and efficient identification for LI and LII ploidy than the conventional methods of using guard cell length for LI and pollen size for LII. 相似文献
56.
Summary To improve the efficiency of papaya anther culture, we investigated (1) hormonal medium conditions for inducing haploids or dihaploids; (2) identified the sex of established plantlets using a sex-specific DNA molecular marker and (3) estimated their ploidy by flow cytometry analysis of DNA content. Anthers with a mixture of uninucleate, mitotic, and binucleate microspores were collected from a male plant, and cultured on MS agar medium with different concentrations of CPPU and NAA. An embryo induction rate of 13.8% was attained on MS agar medium with 0.01 mg l−1 CPPU and 0.1 mg l−1 NAA. The induced embryos were subcultured on medium with 0.0025 mg l−1 CPPU. Rooting of the developed shoots was promoted by treating their basal parts with 1500 mg l−1 IBA in a 50% ethanol solution for about 10 seconds. All the embryo-derived plantlets (27 plants) were identified as female, implying that they were derived from microspores. In addition, 26 plants were determined to be triploids and one to be tetraploids. We also observed a wide range of morphological variation (e.g., in tree height and fruit size) among the established plants. Based on the results, we discussed a potential value of anther culture techniques for the breeding of papaya. 相似文献
57.
Shinichi Nakagawa Terry D. Bannister Fiona R. Jensen Donald A. McLean Joseph R. Waas 《Biology and Fertility of Soils》2002,35(5):390-392
Animals that can distinguish kin from non-kin may enhance their breeding success through "optimal outbreeding". Although relatedness can influence the breeding success of earthworms, no studies of kin discrimination have been conducted in any Oligochaeta species. We determined whether Eisenia fetida Sav. would discriminate kin and change breeding effort with them. The number of cocoons produced (fecundity), viable cocoons, and hatchlings produced by full sibling (inbreeding) and non-sibling (outbreeding) pairs, from different populations, were compared; in this species, fecundity is a reliable indicator of the occurrence and frequency of mating. There were no significant differences in fecundity between inbreeding and outbreeding pairs, so we obtained no evidence for differential investment based on kinship. However, sibling pairs hatched a significantly greater proportion of their cocoons than non-sibling pairs, suggesting that outbreeding depression may reduce reproductive success. We also provide the first evidence for the possibility of parthenogenesis in this species. 相似文献
58.
59.
Structural characterization and biological activities of an exopolysaccharide kefiran produced by Lactobacillus kefiranofaciens WT-2B(T) 总被引:1,自引:0,他引:1
Maeda H Zhu X Suzuki S Suzuki K Kitamura S 《Journal of agricultural and food chemistry》2004,52(17):5533-5538
Lactobacillus kefiranofaciens, isolated from kefir grains, produces an extracellular polysaccharide when cultured, not only in PYG10 medium but also in a liquid medium containing a rice hydrolysate that had been previously degraded by treatment with a glucoamylase. The maximum yield of the polysaccharide, using the rice hydrolysate as the medium, was 2.5 g/L after a 7-day culture period at pH 5.0 and 33 degrees C. Compositional analysis, methylation analysis, specific rotation, and (1)H and (13)C NMR spectroscopy revealed that the structures of polysaccharides obtained from these two different culture media are essentially identical. The polysaccharide is composed of a hexasaccharide repeating unit and, thus, is known as kefiran. The weight-average molecular weight and the z-average radius of gyration of a sample, purified from the rice hydrolysate medium, were determined to be 7.6 x 10(5) g/mol and 39.9 nm, respectively, by gel permeation chromatography equipped with a multiangle laser-light-scattering photometer. Changes in blood pressure and serum components were examined in SHRSP/Hos rats, using doses of 100 and 300 mg of kefiran/kg of rat. A suppression in the increase in blood pressure was observed in these rats after 30 days. This activity is discussed in terms of the concentration of serum components of the rat, with emphasis on lipid components such as cholesterols, triglycerides, and free fatty acids. 相似文献
60.
Shinichi Ogiyama Kazunori Sakamoto Hiroyuki Suzuki Shingo Ushio Tetsuo Anzai Kazuyuki Inubushi 《Soil Science and Plant Nutrition》2005,51(6):801-808
An experiment was conducted to examine the accumulation and mobility of heavy metals (Zn and Cu) at different depths in three types of arable soils (Brown Lowland soil, Andosol, and Brown Forest soil) amended with cattle and pig farmyard manures for 5 years. Nitric-perchloric acid digestion was performed for the determination of the total amounts of heavy metals, and 0.1 M hydrochloric acid extraction was performed for the determination of the amounts of soluble heavy metals. Results of the soil analysis indicated that pig farmyard manure application resulted in serious contamination of arable soils with Zn and potentially Cu. Especially, the Brown Forest soil displayed a high ability to accumulate heavy metals on the soil surface. Total-Zn concentration in surface soils was considerably affected by the holding capacity of soluble-Zn traction. Although the Andosol amended with pig farmyard manure showed higher concentrations of heavy metals related to the higher ability of retention on a weight basis, the soil did not contribute to high heavy metal accumulation because of its low bulk density. Heavy metals were easily leached in sandy soils such as Brown Lowland soil, and Cu was potentially stable compared with Zn. We suggest that long-term pig farmyard manure application to the Brown Lowland soil and Andosol with a light soil texture is associated with a higher risk of groundwater pollution than the application to the Brown Forest soil. 相似文献