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31.
This study was conducted to evaluate drought tolerance and persistence in a germplasm of smooth bromegrass and association of forage productivity with different traits. Thirty‐six genotypes of smooth bromegrass were clonally propagated and evaluated under two soil moisture environments for three years (2013–2015). High genotypic variation was observed among genotypes for all the measured traits. Drought stress decreased mean values for traits related to productivity. Also, the long‐term stress for three years reduced the persistence of plants. Results indicated that indirect selection based on components of forage yield, which had high heritability and high correlation with yield, would be more effective to improve drought tolerance in this germplasm. The results of principal component analysis showed that there was a negative relationship between phenological traits with the persistence‐related traits and yield production. This suggests that selection for earliness may indirectly promote persistent genotypes. The results showed that some Hungarian genotypes are valuable gene sources for persistence. The most persistent genotypes from both groups (Iranian and foreign) were identified using the biplot method. These genotypes may be useful for the development of populations for future studies.  相似文献   
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Tropical Animal Health and Production - This study investigated the effect of different levels and consumption periods of Aspergillus oryzae meal on performance, carcass characteristics, blood...  相似文献   
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Tropical Animal Health and Production - Bovine viral diarrhea virus (BVDV) and bovine herpes virus-1 (BHV-1) remain as the major pathogens with heavy economic consequences in Iran. The prevalence...  相似文献   
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利用杨树人工林剩余物生产刨花板可行性研究   总被引:1,自引:0,他引:1  
The composite board industry in Iran is obliged to use residues from forest operation as well as wood industry for competing with paper industry because of shortage of wood. In the present study we investigated the residues from poplar plantation used for particleboard production. Three kinds of wood materials, poplar branches, small diameter poplar wood (3–8 cm) and beech wood, were used in the experiment of particleboard production. The results demonstrated that the characteristic of particleboard made from poplar branches and small diameter wood is comparable to that made from mature beech wood. To avoid too much residual acid in the final board, the properties of boards produced with 1.5% hardener at 175°C press temperature are acceptable, although the properties of particleboard produced with 2% hardener were higher than were higher than that of the board produced with lower hardener (1% or 1.5%).. The MOR, MOE and IB of particleboard made from branches were measured as 14.57, 2015, and 1.32 MPa, respectively, while The MOR, MOE and IB of particleboard produced from small diameter poplar wood were 19.90, 2199, and 1.86 MPa, respectively. The thickness swelling of boards made from branches after 2 and 24 h immersion in water was 20.14% and 31.26%. The utilization of branches and very small diameter wood of poplar is recommended for the survival and developments of particleboard industry in Iran.  相似文献   
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The use of low-quality whole dates in broilers’ diets was evaluated. The apparent metabolizable energy (AMEn) of whole dates and date pits was determined with or without a β-mannanase-based enzyme (Hemicell – a registered trademark of ChemGen Corp., Gaithersburg, MD. Dried Bacillus lentus fermentation solubles with 158 million units/kg minimum enzyme activity. Recommended usage rate is 0.4 g kg−1 of feed. ChemGen Corp., Gaithersburg, MD, USA). A 3 × 2 factorial arrangement consisting of whole dates (0, 175, and 350 g kg−1) and enzyme (0 or 0.4 g kg−1) was performed to assess the effect of the enzyme on the nutritive value of whole dates (experiment 2) in broilers’ diet. Enzyme improved AMEn contents of the whole dates and date pits. The diets containing 175 or 350 g kg−1 whole dates produced body weight gain (BWG) similar to those obtained without dates. Enzyme improved BWG and feed conversion ratio throughout the experimental period. In conclusion, whole dates can be included in broiler diets at levels up to 350 g kg−1. In addition, β-mannanase supplementation would have beneficial effects on performance and immunity in birds fed on corn–soy or corn–soy–whole dates diets.  相似文献   
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There are several methods for the diagnosis and evaluation of coarctation of the aorta. Digital Subtraction Angiography (DSA) is the standard detection method, though it entails complications and side-effects. The aim of the present study was to compare Computed Tomography (CT) angiography with DSA for diagnosing aortic coarctation. We performed a cross-sectional study of 15 patients (11 males and four females aged between two and 30 years) referred to Tabriz Shahid Madani Hospital and Imaging Center between August 2005 and February 2006 with suspected aortic coarctation. All patients were subjected to DSA and CT angiography for diagnosis of aortic coarctation. The mean age of the patients was 14.6 years; 11 were male (74.4%) and four (26.6%) were female. The DSA and CT angiography results were comparable in all patients in terms of diagnosis and the detection of complications, particularly cardiovascular complications. However, CT angiography was less time-consuming to perform than DSA (p < 0.0001). In conclusion, CT angiography, comparableto DSA, diagnosed coarctation of aorta in all the patients. However, CT angiography is a non-invasive, cost effective procedure that takes significantly less time to carry out than DSA. Therefore, CT angiography is recommended as an appropriate method for diagnosing the coarctation of aorta.  相似文献   
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This paper critically reviewed the current knowledge and challenges of rice husk biochar(RHB) production and its effects on soil properties, plant growth, immobilization of heavy metals, reduction of nutrient leaching and mitigation of greenhouse gas emissions. The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agroindustrial wastes. RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio, which suggests the presence of higher aromatic carbon compounds. The increase of pyrolysis temperature also results in production of RHBs with higher ash content, lower yield and higher surface area. RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions. Although it depends on soil type, RHB application can improve soil organic carbon content, cation exchange capacity, available K concentration, bulk density and microbial activity. The effect of RHB on soil aggregation mainly depends on soil texture. The growth of different crops is also enhanced by application of RHB. RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability. RHB application shows a significant capacity in reduction of nitrate leaching, although its magnitude depends on the biochar application rate and soil biogeochemical characteristics. Use of RHB, especially in paddy fields, shows a promising mitigation effect on greenhouse gas(CH_4, CO_2 and N_2 O) emissions. Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time, its performance for specific applications(e.g. carbon sequestration, p H amendment) can be manipulated by adjusting the pyrolysis temperature. More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment.  相似文献   
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