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21.
The mechanical and physical properties of spun yarns and fabrics depend not only on mechanical properties of the fibers making up the yarn, but also geometrical arrangement of fibers, known as fiber migration. The main aim of this research is to introduce a new approach to predict migratory behavior of spun yarns. Achieving the objectives of this research, general physical, mechanical and structural properties of spun yarns together with existing standards were thoroughly studied. A hybrid intelligent model was developed based on a Genetic Fuzzy System (GFS) to model the relationships between migration of fibers in spun yarns and some physical and mechanical properties of spun yarns. Results indicated that the developed fuzzy expert system can be used as an intelligent simulator to predict yarn migratory parameters.  相似文献   
22.
The effect of ammonium:nitrate (NH4:NO3) ratio in nutrient solution on growth, photosynthesis (Pn), yield, and fruit quality attributes in hydroponically grown strawberry (Fragaria × ananassa Duch) cvs. ‘Camarosa’ and ‘Selva’ was evaluated. There were four nutrient solutions of differing NH4:NO3 ratios as follows: 0:100, 25:75, 50:50, and 75:25. Plants grown in solution with 75% NH4 had lower leaf fresh and dry weights and leaf area than those with 25% NH4 in both cultivars. High ratios of NH4 and NO3 in the solution always reduced the yield. The yield was increased by 38% and 84% in ‘Camarosa’ and ‘Selva,’ respectively, when the plants were grown in the 25NH4:75NO3 solution compared with plants grown in a higher NH4 ratio solution. The increased yield at the 25 NH4:75NO3 ratio was the result of the increase in fruit size, i.e., length and fresh weight of fruits. Plants grown in the 25NH4:75NO3 solution had the highest rate of Pn, while those grown in 75NH4:25NO3 solution had the lowest Pn rates in both cultivars. Increasing the NH4 ratio in the solution from 0 to 75% significantly reduced the calcium (Ca) concentration and postharvest life of the fruits in both cultivars. Both higher leaf area and Pn rate appeared to be the reason for the increased yield and plant growth in the 25:75 ratios of nitrogen (N). The results indicate the preference of strawberry plant growth toward a greater nitrate N form in a hydroponic solution. Therefore, a combination of two forms of N in an appropriate ratio (25NH4:75NO3) appears to be beneficial to plant growth, yield, and quality of strawberry fruits.  相似文献   
23.
Animal forage plays an important role in agriculture. To maintain the silage quality during storage, preserving it from decomposition by wrapping the harvested crop with plastic stretch film is crucial. Any failure in the preserving process permits the infusion of oxygen, which allows the growth of undesirable aerobic microorganisms and silage decomposition. To study the state of the silage, temperature inside the stack could be used as indicator of decomposition. However, no previous study has developed a model that can detect decomposition based on abnormal temperature variations inside a silage stack. The first objective of this paper was to develop a structured nonlinear model to estimate the dynamics of temperature variations measured by a wireless sensor network-based monitoring system (nRF95E) inside a silage bale and stack prior to the decomposition process. The requirement of a robust nonlinear model is that sensor nonlinearities that are inherent in nature are considered. The results showed that a Hammerstein-Wiener (HW) model with sigmoid network performed the best in terms of percentage of fit (91.70%) between the measured and simulated output. The second objective was to estimate the length of time required to detect the decomposition process after the airtight seal was punctured using the model. The error between the predicted model output and the sensor readings exceeded a preset threshold interval 17 days after the cover film was punctured and 9 days after the decomposition process was detected due to the odour released.  相似文献   
24.
The objective of this paper was to investigate the effect of limited grazing time on urination and defecation frequency, spatial distribution of excrement in the paddock, and the resulting nitrogen balance at animal and field level. During a 6-week period in early summer, 60 Holstein Frisian dairy cows (31.0 ± 5.4 kg ECM) were randomly allocated to three different treatments, with grazing at clover-grass pasture during daytime for 4, 6.5 or 9 h daily. Indoor feeding, with a mixture of roughage and concentrates (13% crude protein), was restricted for treatment 4 and 6.5 h to the amount the 9-h treatment could eat. Cows allowed grazing at pasture for 4 h moved more rapidly during pasture, moved longer distance per active hour and used a higher proportion of the time eating, both at pasture and indoor, than the cows allowed longer time at pasture. Limiting the grazing time had no influence on the urination (mean = 0.26) and defecation (mean = 0.37) frequency per cow per hour during pasture. Even though the proportion of time active (eating, drinking, standing or walking), and the actual time active during pasture was different for the treatments, the frequency of urination and defecation per active hour was also unaffected by the treatments. Urine and faeces were distributed in the pasture, without specific hot-spots. The estimated daily N-balance at animal level showed increased N excretion with time at pasture. Assuming that excretion follows the active periods during the day and 7000 kg DM foliage is available on yearly basis, this would result in total excretion at field level of 58, 86 and 108 kg N per ha respectively for treatment 4, 6.5 and 9 h. The results of this experiment show that it is possible to reduce the nitrogen excretion in a grazing system by restricting the grazing time of dairy cows together with restricted indoor feeding while maintaining high foliage intake.  相似文献   
25.
ABSTRACT

Incorporating deep litter cow and deep litter poultry manures with the top 30-cm soil improved orchard soil chemistry, including nutrient availability, soil organic matter, electrical conductivity (EC), pH, cation exchange capacity (CEC) and biological activity in a ‘Golden Delicious’ apple (Malus domestica Bork) orchard in Zanjan, Iran. Application of deep litter cow manure at 30 t ha?1 or deep litter poultry manure at 10 t ha?1 resulted in a higher rate of nitrogen (N) release, and thus increased yield and fruit size, but decreased fruit color. The least leaf minerals were found in the untreated control trees. The control trees showed minor symptoms of N, iron (Fe), and magnesium (Mg) deficiencies during the following season. Positive correlation existed between the rate of manure applied and the content of soil organic matter (OM). The deep litter poultry manure at 10 t ha?1 increased the soil K, Mg, calcium (Ca), ammonium-N, and EC levels.  相似文献   
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Spirulina has been highlighted as a valuable complementary ingredient in aquafeeds due to its high protein and vitamin content, in addition to other nutritional benefits. To evaluate the effect of dietary spirulina inclusion in fish meal sparing (FMS) on juvenile Caspian brown trout as a slow‐growth fish, a complete randomized experimental design was developed with five treatments: 0% (control), 2% FMS (13.2 g/kg spirulina in diet), 4% FMS (26.4 g/kg spirulina in diet), 6% FMS (39.6 g/kg spirulina in diet) and 8% FMS (52.8 g/kg spirulina in diet). Six hundred juveniles (11.0 ± 1.0 g) were assigned to 15 experimental tanks. Although this fish is sensitive to diet composition, fish fed the 6% FMS and 8% FMS diets had a significantly higher weight gain rate (239.51% and 231.27%) and specific growth rate (1.74% bw per day and 1.71% bw per day) compared with those fed the control diet. Furthermore, 6% FMS and 8% FMS treatments had statistically higher protein efficiency (0.76 and 0.78), lipid efficiency (1.89 and 1.94) and statistically lower feed conversion ratio (2.47 and 2.41) compared with other treatments, respectively (p < 0.05). In terms of whole‐body composition, the higher amount of protein and lower content of lipid were observed in fish fed the 8% FMS diets as compared to control. Although no significant differences in ash and moisture content were observed, the highest protein deposition (157.3 g/kg) and the lowest lipid content (77 g/kg) in whole body were reported in fish fed 8% FMS diet. Based on the fillet fatty acid outcome, fish fed the 8% FMS diet had significantly higher saturated fatty acids (SFAs), C20:3n‐6, C18:3n‐3, polyunsaturated fatty acids (PUFAs) and total n‐3 fatty acids as compared to those fed the control diet (p < 0.05). Accordingly, increasing dietary spirulina content significantly enhanced the amount of these fatty acids in fish fillet. As regards of whole‐body amino acid profile, arginine and lysine in fish fed 6% FMS and 8% FMS diets were higher and lower than in those fed the control diet, respectively (p < 0.05). Fillet and skin colour parameters, such as luminosity, redness and yellowness, significantly increased with spirulina supplementation with the 8% FMS treatment displaying higher values than the control. In summary, according to our results, 8% FMS (52.8 g/kg spirulina in diet) treatment improved juvenile Caspian brown trout growth, carcass composition and pigmentation.  相似文献   
29.
Adsorption and release are the most influential reactions controlling zinc (Zn), manganese (Mn) and copper (Cu) availability in soils. Characteristics of native Zn, Mn and Cu release by ethylenediaminetetraacetic acid (EDTA) in two calcareous soils for periods from 1 min to 24 h were studied. The pattern of Zn, Mn and Cu release from both soils fitted well with power function, Elovich and parabolic diffusion models. The magnitude and rate of release was greatest for Mn, followed by Zn and Cu, respectively. This trend suggests a higher ability of the studied soils to replenish soil solution Mn, compared with Zn and Cu. The results showed that higher Mn release in clay soil compared with sandy loam soil was considerably related to higher initial Mn release rates in the former compared with the latter. However, Cu release rates of the two soils at initial times were not significantly different. Higher Cu release in clay soil was, therefore, attributed tohigher Cu release rates at subsequent time intervals. It is assumed that the different Zn release rates of these soils were due to consistent differences in Zn release rates throughout the release periods.  相似文献   
30.
Aquaculture International - The objective of the present work was to survey the effects of different sources of zinc supplements on serum enzymatic activities, the expression of genes related to...  相似文献   
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