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1.
The present review has been focused largely on the sex type differences in beef quality among heifers, cows, steers and bulls in various feeding environments. Genetic groups, feeding systems and gender are the major factors that change carcass characteristics and fatty acid profiles of cattle. Studies identified that heifer beef has super characteristics in eating quality and a better healthy composition in fatty acids than steer, cow and bull. Diet influences the variation of fatty acid profile; particularly the level of polyunsaturated fatty acids (PUFA) interacts with breed and sex. Animals finished in pasture systems were reported to show better ratios of PUFA/ saturated fatty acids and n‐6/n‐3. Carcasses of roughage‐fed beef are lighter and have less marbling and lower quality grades but have higher cutability than carcasses of grain‐fed bulls. Heifers and cows are reported to deposit more fat than steers and bulls. Among males, lower production of testosterone by steers favors more fat thickness compared with bulls. Marbling greatly varies among cattle belonging to different sexes, and particularly, females have genetic makeup that efficiently controls deposition. The current review identified that heifers can be a premium beef brand, while steer beef currently take a large part of market share across the world.  相似文献   
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The germination of Casuarina equisetifolia Forst seed lots is low (40–50%) even when freshly collected. This study aimed at upgrading the germination performance by removing non-germinable seeds using petroleum flotation technique. Seeds collected from 19 individual trees in seedling seed orchards in India were assessed using X-ray to determine the proportion of different seed lot fractions. The feasibility of petroleum ether as a separation medium was tested. Morphological characters of floating and sunken seeds were further studied using image analysis technique to examine their effects on the separation efficiency. The X-ray analysis revealed a large quantity of shrivelled, empty and insect-damaged seeds, altogether accounting 50%, which were the causes of low percentage germination of un-graded seed lots (48%). Petroleum flotation resulted in 90% germination in the sunken fraction and 4% in the floating fraction. The separation was distinct for most seed lots, except few seed lots that had relatively low germination in the sunken fractions and more than 10% germination in the floating fractions. As a whole, petroleum flotation appears to be a feasible technique to upgrade the germination of C. equisetifolia seed lots, and its efficacy is influenced by wing surface area, seed density and wing quotient of filled and empty seeds.  相似文献   
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Model system for testing the efficacy of antioxidants in muscle foods   总被引:3,自引:0,他引:3  
The objective of this research was to study the effect of the antioxidants, delta-tocopherol, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylhydroquinone (TBHQ), and propyl gallate in a model system of lean muscle and canola oil and to compare the effects with those in minced herring. Two carrier solvents with different dielectric constants (epsilon), ethanol (epsilon = 24) and oil (epsilon= 2), were used. Oxidation was measured using thiobarbituric acid reactive substances (TBARS) and sensory analysis. In both the lean muscle-canola oil model system and in herring muscle, the hydrophilic antioxidants, propyl gallate and TBHQ, were more effective in providing oxidative stability than the lipophilic antioxidants, delta-tocopherol and BHT. The oxidative stability of a cod muscle-canola oil system in the presence of propyl gallate, and delta-tocopherol was not affected by the dielectric constant of the carrier solvent, while BHA was more effective as an antioxidant when added in the polar solvent ethanol.  相似文献   
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Changes in the conformation of catfish (Ictalurus punctatus) myosin due to (i) anions, (ii) acid pH, and (iii) salt addition were determined using tryptophan fluorescence, hydrophobicity measurements, differential scanning calorimetry, and circular dichroism. The relationship between conformation and storage modulus (G') of acid-treated myosin was studied. Three acids, HCl, H2SO4, and H3PO4, were used for unfolding myosin at three acidic pH conditions, 1.5, 2.0, and 2.5. Unfolded myosin was refolded to pH 7.3. Denaturation and unfolding of myosin was significantly (p < 0.05) lower when salt (0.6 M NaCl) was present during acid unfolding than in the absence of salt. When salt was added before unfolding, the alpha-helix content of myosin treated at pH 1.5 was significantly lower than that treated at pH 2.5. When salt was added after refolding, the alpha-helix content of myosin was unaffected by different pH treatments. The G' of myosin increased with an increase in myosin denaturation. The G' of myosin was significantly (p < 0.05) higher when salt was added to myosin after refolding than before acid unfolding. Among the different anion treatments, the G' of acid-treated myosin decreased in the order Cl- approximately SO42- > PO43-. Among the different pH treatments, the G' of myosin treated at pH 1.5 was significantly (p < 0.05) higher than myosin treated at pH 2.5. The conditions that would result in maximum myosin denaturation and maximum G' were unfolding of myosin at pH 1.5 using Cl- (from HCl) followed by refolding at pH 7.3 and subsequent addition of 0.6 M NaCl.  相似文献   
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  1. India plays a significant role in dugong conservation by having the largest population within South Asia. The status of dugongs in India is largely unknown due to a paucity of reliable ecological data. This study generated mitochondrial control region sequences from ~10% of dugong individuals from existing populations within India. Furthermore, data generated in this study were compared with the global data to assess genetic lineages, population structure, and genetic diversity of Indian populations.
  2. Multiple analyses suggest that the Indian dugong populations are part of a single genetic cluster, comprising South Asia, North-west Indian Ocean, and South-west Indian Ocean populations. Despite small population size, they retain high genetic diversity with unique mitochondrial DNA haplotypes within South Asia. Within India, novel haplotypes are observed from all dugong habitats sampled, with overall high haplotype diversity (0.85 ± 0.04) but low nucleotide diversity (0.005 ± 0.001). Indian populations exhibit genetic differentiation with higher within-population variance (63.41%) than among populations (36.59%). Two of the haplotypes observed in India are shared with Sri Lanka, implying genetic connectivity between these populations.
  3. The genetic data from Indian dugong populations provide critical insights into the identification of dugong corridors and important dugong conservation zones in India. We suggest site-specific interventions, including the creation of new marine protected areas and boundary reorganization and expansion of other existing protected areas, to ensure population connectivity. In addition, simultaneous efforts towards seagrass meadow restoration, reduction of dugong mortalities, and community participation in dugong conservation are recommended for population recovery of this threatened marine herbivore.
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The effects of modified atmosphere packaging (MAP) [bioriented polypropylene (BOPP-1 or BOPP-2)] in combination with antimicrobial agents Bacillus subtilis, 107 colony-forming units (cfu) ml−1; ethylenediamine tetraacetic acid, calcium disodium salt hydrate (EDTA) (0.1%); or 4-hexylresorcinol (4-HR) (0.15%) on postharvest decay control and quality retention of litchi cv. McLean's Red were assessed as possible replacements for commercial SO2 fumigation. Fruits dipped in B. subtilis, EDTA or 4-HR (5 min) separately, blow dried (25 °C, 3 min), packed in BOPP-1, held for 18 d at 2 °C, 95% RH, and 2 d at 14 °C, 75% RH were significantly less decayed. The antagonist–BOPP-1 combination also promoted the best bacterial survival during storage. B. subtilis was observed to survive effectively in BOPP-1 (16% O2, 6% CO2; 90% RH), but its survival was adversely affected in BOPP-2 (5% O2, 8% CO2; 93% RH). Alternaria alternata and Cladosporium spp. were the major decay-causing fungi in BOPP-1 treatments, and Candida, Cryptococcus and Zygosaccharomyces were the predominant yeasts in BOPP-2 treatments. Combination treatments EDTA, 4-HR or B. subtilis in BOPP-1 inhibited polyphenol oxidase (PPO) and significantly reduced pericarp browning and severity. Although the combination treatments EDTA, 4-HR or B. subtilis in BOPP were equally effective in controlling decay and browning, the EDTA and 4-HR affected the natural pinkish-red colour of the pericarp by showing higher h° values (orange–pink). Among the combination treatments, B. subtilis+BOPP-1 had the best potential to control decay, retain the colour and the overall litchi fruit quality during a marketing chain of 20 d.  相似文献   
10.
Grain yield and yield components (grains per ear, grain weight, 1000-grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW-343) with well-filled grains and a Triticale genotype (DT-46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear−1 and abscisic acid (ABA) @4 µg ear−1 were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale , BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale . The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth-promoting phytohormones such as cytokinins and assimilates.  相似文献   
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