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31.
This study designed an organic farmer's behavior model based on the Ajzen’s theory of planned behavior. The methodology was Mixed Method Research. In the qualitative phase, ten rice producers who received healthy product certification from Standard Organization were interviewed. The results of qualitative research showed that factors affecting the organic farming conversion consisted of facilitating factors and barriers. Facilitating factors include motivations and profits and barriers include challenges and costs. In quantitative phase, 250 rice producers were randomly interviewed. The results of quantitative research showed that attitude and subjective norms of rice producers have a significant positive effect on their intension toward organic farming. Ajzen’s model has been improved by adding variables such as knowledge, self-identity and moral obligation . As a result, the model is improved and approximately 92 % of the variance of rice producers’ behavior in organic farming is explained by research variables.  相似文献   
32.
Abstract

Zinc (Zn) as a microelement plays a salient role in the vital processes of plants such as metabolism and nutrition. This experimental study was conducted in the research field of Agriculture Faculty, Zanjan University using two genotypes of canola as main factor (Okapi and Tassilo) and zinc fertilizer application method in 7 levels including control, foliar spraying (2, 3.5, and 5?g/L) at the beginning of flowering and soil application (25, 50, and 75?kg/ha) were considered as sub-plot factor. The results showed that the application of zinc significantly increased the chlorophyll content as compared to control treatment. The highest chlorophyll content was observed in foliar spraying of 3.5 and 5?g/L zinc in Okapi cultivar. While, the highest value of RWC content resulted only with spraying 5?g/L of zinc. The result showed that zinc foliar of 5?g/L obtained the highest oil and seed yields and seed yield components. In addition, the highest qualitative seed traits (oil and protein content and zinc content in seed and plant) resulted with spraying 5?g/L of zinc. Also, Okapi cultivar had more quantitative and qualitative yields than Tassilo cultivar. The foliar spray of 5?g/L Zn can be recommended to increase the quantity and quality seed yield of canola.  相似文献   
33.
Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter (DBH) to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter (age) typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%?64.3%, 15 cm?75 cm, and 2.0?19.5 m, respectively. With increasing trunk diameter, the proportion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological characteristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter >1 m do not provide valuable round wood for industries and cause to raise wood production costs. We recommend that these trees >1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosys-tems.  相似文献   
34.
Four different arbuscular mycorrhizal (AM) fungi, Glomus aggregatum, Glomus fasciculatum, Glomus intraradices and Glomus mosseae, were used alone and in combinations with Bacillus subtilis to evaluate their capability to increase the productivity of geranium. Mycorrhizal treatment increased the growth and total biomass invariably over non-mycorrhizal control plants. In AM alone treatment, the best result was obtained for G. mosseae treatment, where 380.9 and 335.3 g fresh herb yield per pot was recorded in 2005–2006 and 2006–2007, respectively, an increase of 75.3 and 85.9% over controls. Plants inoculated with B. subtilis alone yielded 287.8 and 252.3 g fresh herb, an increase of 32.4 and 39.9% over uninoculated controls. However, B. subtilis in combination with G. mosseae produced the highest herb yield, i.e. 410.8 and 347.8 g herbs pot?1, an increase of 89.4 and 92.9% over untreated controls. The field experimental data validated the results of the pot experiment. Treatment with G. mosseae alone increased herb yield by 49.4%, whereas in combination with B. subtilis, it increased herb yield by 59.5%. Treatment with AM fungi and B. subtilis did not affect the essential oil content of the plant, but total oil yield was significantly increased because of the increase in biomass production.  相似文献   
35.
The present article was conducted to evaluate the effect of in ovo injection of arginine on hatchability, immune system and caecum microflora of broiler chickens. For this reason, 300 fertile eggs were used in a completely randomized design with three experimental treatments. The experimental groups included: 1%–0.5% l -arginine (100 eggs), 2%–1% l -arginine (100 eggs), 3- control [included both sham control (injection of distilled water; 50 eggs) and control (no injection; 50 eggs)], which were injected on d 14 of incubation. After hatching, chicks of each experimental group (0.5% l -arginine, 1% l -arginine, and control groups) were randomly divided into four equal groups (as replicates) and reared for 30 days. Weight and feeding of chickens were recorded. Next, blood samples of chickens were collected on day 30 to evaluate antibody titre. Also, chickens were slaughtered on 24 and 30 days of the experiment to evaluate immune system organs and caecum microflora. Based on the results, in ovo injection of l -arginine had no significant effect on hatchability, body weight, antibody titre, spleen, bursa of Fabricius and thymus weight (p > .05). On the other hand, treatments significantly affected feed intake and feed conversion ratio (p < .05). As a novel finding, in ovo injection of l -arginine increased caecal Lactobacillus (p < .01), while decreasing Coliform and Escherichia Coli bacteria (p < .01). However, treatments did not influence caecal Enterococcus (p > .05). The overall results indicated that in ovo injection of 0.5% l -arginine had a better improving effect on caecal microflora and then considered as a recommended level of the present experiment.  相似文献   
36.
Clay liners remain an important component of composite liners used in landfill construction. Because their hydraulic integrity is frequently lost due to desiccation cracking, either during construction or shortly thereafter. The present study was initiated to evaluate the effects of common soil additives including lime, cement, and sand on the shrinkage and hydraulic conductivity of compacted clay soils commonly used in clay liner construction. Three soils having predominant clay minerals of smectite, illite and kaolinite were amended with varying amounts of lime, cement or sand; compacted using the Harvard miniature compactor; and the volumetric shrinkage was measured on the compacted samples. Additional samples of each treated soil were compacted according to ASTM 698 and used for measurement of the hydraulic conductivity. The results show that the majority of shrinkage occurs when the samples were dried to 25 °C with little additional shrinkage at temperatures up to 105 °C. The amendments of either 4% lime or 40 to 50% sand resulted in reduced shrinkage and increased hydraulic conductivity. The addition of 3% cement reduced shrinkage by up to 50% and simultaneously reduced hydraulic conductivity by 2 orders of magnitude. Thus, amendment of clay soils having a high shrink-swell potential with Type I Portland cement has the greatest poetential for field application as an amendment to help maintain the integrity and improve the long term performance of compacted clay liners.  相似文献   
37.
Despite our best efforts to reduce the waste stream, there will always remain some residues which cannot be further treated and must be disposed in landfills. One critical aspect of landfill construction is the integrity of the landfill liner. Current landfill liner technology includes a composite liner which consists of a FML component and a compacted soil component. The primary characteristic for selecting a soil for use in composite liner construction is that the soil have a saturated hydraulic conductivity of 1 × 10?7 cm s?1 or less. In the present study the effects of desiccation cracks on the hydraulic conductivity of the compacted soil were measured. Two soils of diverse mineralogy and typical of soils used for clay liner construction were selected for use. Each was tested in its native state plus after the addition of 30% sand. Laboratory measurements were made of the volumetric shrinkage of each soil. In addition, the hydraulic conductivity was determined using 10 cm diameter fixed wall permeameters. Additional conductivity measurements were made using 60 cm diameter fixed wall double ring permeameters which had been exposed to 0, 1, and 2 periods of desiccation prior to hydraulic conductivity determinations. The data show that laboratory measurements using 10- cm diameter fixed wall permeameters underestimate the hydraulic conductivity of the same soils when packed in large diameter permeameters. It was also found that exposure to two cycles of desiccation resulted in large increases in hydraulic conductivity. The time required to reach a steady outflow volume decreased as the amount of desiccation increased. The hydraulic conductivities of soils which had been allowed to dry were greater than those which were not allowed to dry prior to measurement. The relationship between volumetric shrinkage and the increase in hydraulic conductivity after desiccation indicates that soils which exhibit less than 11% shrinkage in the laboratory, exhibit increases in K of less than a factor of 2 upon desiccation. Clay soils with greater than 11% shrinkage can potentially be amended with sand to decrease the volumetric shrinkage and their response to desiccation.  相似文献   
38.
Anaphylactic reaction rarely occurs after the 1st injection of penicillin-streptomycin in cattle. Immediately following intramuscular injection of a Holstein-Friesian cow with penicillin-streptomycin, the cow showed abnormal clinical signs that included respiratory distress, urticaria, and lacrimation. Recovery took approximately 2 h after intramuscular injection of dexamethasone. This report presents clinical findings recorded 20 and 40 h later.  相似文献   
39.
European Journal of Plant Pathology - Virus-induced gene silencing (VIGS) is a reverse genetic tool used to identify the function of individual genes by reducing their expression. Here VIGS was...  相似文献   
40.
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