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101.
The purpose of this study was to determine the effectiveness of dry heat, steam, and microwave treatments in decreasing lipase activity, while retaining antioxidant activity, to stabilize whole wheat flour against lipid degradation during storage. Bran was heat‐treated in 230‐g batches using four levels (exposure times) for each of the three treatment methods. Lipase activity and antioxidant activity were quantified for all treatment combinations. None of the treatments significantly decreased antioxidant activity; the levels determined to be optimal, inasmuch as further heating did not significantly decrease lipase activity, were 25 min of dry heat, 60 sec of microwave (1000W), and 60 sec of steam. These treatments effectively decreased lipase activity by 74, 93, and 96%, respectively. Optimum treatments were evaluated for acceptance using a consumer sensory panel during a 12‐month storage period. No significant differences in acceptance were found between the control and any of the samples either at baseline or after storage. This suggests that whole wheat flour can be stabilized against lipolysis by utilizing the treatments described in this study without decreasing antioxidant activity, and that manufacturers may utilize these treatments without risking decreased consumer acceptance.  相似文献   
102.
Tumorous crown gall tissue induced on the stems of sunflower (Helianthus annus L. cv. Mammoth Russian) plants by the soil bacterium Agrobacterium tumefaciens strongly reduced Fe3+ to Fe2+ as evidenced by the formation of Fe2+ BPDS complex compared to surrounding “normal” stem tissue. Tumorous tissue contained significantly more Fe, Cu, K, and P, and less Zn and Mg than the nontumorous stem tissue. The reducing environment of the tumorous tissue appears to affect the general nutrition and growth of this tissue.  相似文献   
103.
Although agaves are commercially important worldwide and ecologically interesting, their nutrient responses have not been extensively studied under controlled conditions. Here, nutrient responses of seedlings and adult plants of Agave deserti were examined, with particular emphasis on nitrogen. Growth of seedlings in hydroponics was enhanced by increasing potassium, phosphate, and especially nitrate. Seedling growth in sand culture was also enhanced by adding nitrate, leading to just over 2% N by dry weight in the leaves. Seedlings had optimal growth in soil having about 0.1% N by dry weight and a pH between 6 and 8. In going from irrigation with no added nutrients to full‐strength Hoagland solution for mature plants in soil, leaf unfolding (a non‐destructive measure of productivity) approximately doubled. The rate of leaf unfolding in the field was also doubled by adding 100 kg N hectare‐1, higher levels proving inhibitory.  相似文献   
104.
Fusarium verticillioides and Aspergillus flavus cause Fusarium ear rot (FER) and Aspergillus ear rot (AER) of maize, respectively. Both pathogens are of concern to producers as they reduce grain yield and affect quality. F. verticillioides and A. flavus also contaminate maize grain with the mycotoxins fumonisins and aflatoxins, respectively, which has been associated with mycotoxicosis in humans and animals. The occurrence of common resistance mechanisms to FER and AER has been reported. Hence, ten Kenyan inbred lines resistant to AER and aflatoxin accumulation were evaluated for resistance to FER, F. verticillioides colonisation and fumonisin accumulation; and compared to nine South African lines resistant to FER and fumonisin accumulation. Field trials were conducted at three localities in South Africa and two localities in Kenya. FER severity was determined by visual assessment, while F. verticillioides colonisation and fumonisin content were quantified by real-time PCR and liquid chromatography tandem mass spectrometry, respectively. Significant genotype x environment interactions was determined at each location (P ≤ 0.05). Kenyan inbred CML495 was most resistant to FER and F. verticillioides colonisation, and accumulated the lowest concentration of fumonisins across localities. It was, however, not significantly more resistant than Kenyan lines CML264 and CKL05015, and the South African line RO549 W, which also exhibited low FER severity (≤5%), fungal target DNA (≤0.025 ng μL?1) and fumonisin levels (≤2.5 mg kg?1). Inbred lines resistant to AER and aflatoxin accumulation appear to be promising sources of resistance to F. verticillioides and fumonisin contamination.  相似文献   
105.
The storability of onion bulbs is dependent on the incidence and rate of sprout growth. Exogenous ethylene applied continuously has been demonstrated to act as a sprout suppressant in onion. However, the ethylene binding inhibitor, 1-methylcyclopropene (1-MCP), can also suppress sprouting in onion. Given this seemingly contradictory result, the precise role that ethylene plays during onion storage and the effect of curing on its efficacy is not understood.‘Sherpa’ and ‘Wellington’ onion bulbs were treated before or after curing (28 °C for 6 weeks) with a single dose of 10 μL L−1 ethylene or 1 μL L−1 1-MCP for 24 h at 20 °C, or no treatment (control). Replicated out-turns were sampled during 38 weeks storage at 0–1 °C. Sprout growth (31 weeks after harvest) was reduced in ‘Sherpa’ treated before curing with ethylene or before or after curing with 1-MCP. However, sprout growth of ‘Wellington’ was not affected by any treatment. Following treatment, the cured, thick-skinned ‘Wellington’ released a lower concentration of treatment gas compared with the newly harvested, thin-skinned ‘Sherpa’. Onion bulb respiration rate increased immediately after being treated with ethylene but to a lesser extent or not at all when treated with 1-MCP. Fructose concentrations of onions treated with ethylene or 1-MCP before curing were not significantly different, however, after curing concentrations were about 2-fold higher compared with the control. Mean glucose and sucrose concentrations for both cultivars were higher immediately after being treated before curing with ethylene or 1-MCP than control bulbs. It appears that inhibition of sprout growth can be achieved using just a short 24 h treatment with ethylene or 1-MCP. However, skin thickness or permeability, which is dependent on cultivar and curing, may affect ethylene or 1-MCP influx and therefore efficacy of sprout suppressant action.  相似文献   
106.
The relationship between commuting distances and where people work has been studied for urban contexts in both developed countries and developing countries. However, few studies have examined the situation in rural areas, and none look at commuting distances to non‐farm workplaces in rural areas of developing countries. This paper investigates how commuting distance, and thus accessibility, to local non‐farm work influences non‐farm employment and out‐migration from rural villages in Northeast Thailand. The main issues examined are: (i) the distance that rural residents travel to work in local non‐farm jobs; and (ii) the influence that local non‐farm employment has on the number of outmigrants from rural villages. The study finds: (i) distance between villages and non‐farm work sites impact the number of villagers who are employed in regular wage work; (ii) beyond 20 km villagers are less likely to travel to non‐farm employment using their own means of transportation; and (iii) employment in regular wage work decreases outmigration. The findings from this study contribute to the debates over the drivers of rural out‐migration, rural livelihood changes, and agrarian changes that are taking place in Southeast Asia.  相似文献   
107.
In the past five decades, constant research has been directed towards yield improvement in pigeonpea resulting in the deployment of several commercially acceptable cultivars in India. Though, the genesis of hybrid technology, the biggest breakthrough, enigma of stagnant productivity still remains unsolved. To sort this productivity disparity, genomic research along with conventional breeding was successfully initiated at ICRISAT. It endowed ample genomic resource providing insight in the pigeonpea genome combating production constraints in a precise and speedy manner. The availability of the draft genome sequence with a large‐scale marker resource, oriented the research towards trait mapping for flowering time, determinacy, fertility restoration, yield attributing traits and photo‐insensitivity. Defined core and mini‐core collection, still eased the pigeonpea breeding being accessible for existing genetic diversity and developing stress resistance. Modern genomic tools like next‐generation sequencing, genome‐wide selection helping in the appraisal of selection efficiency is leading towards next‐generation breeding, an awaited milestone in pigeonpea genetic enhancement. This paper emphasizes the ongoing genetic improvement in pigeonpea with an amalgam of conventional breeding as well as genomic research.  相似文献   
108.
109.
This observational study was conducted to identify the cause of death and load level factors associated with mortality in 1 090 733 Manitoba broiler chickens transported to slaughter in spring and early summer. Death loss in transit was 0.346% and accounted for 19% of the total carcass condemnation. The death loss pattern was clearly bimodal, with a low death loss in 180 of 198 shipments. Cumulative death loss during the growing phase of production was consistently associated with increased transport mortalities in load level models and when comparing high death loss with low death loss truckloads. High ambient temperature at the time of slaughter and loading density of the truck were the major factors associated with exceptional death loss.  相似文献   
110.
Dietary unsaturated fatty acids (FA) are intensively hydrogenated in the rumen, resulting in reduced amount of poly‐unsaturated fatty acids (PUFA) and accumulation of several biohydrogenation (BH) products. In this study, BH of PUFA originating from different oilseeds (linseed, soya beans, sunflower seed and rapeseed) present in crushed oilseeds or their free oils were assessed in vitro. The assay substrates were incubated in buffered rumen fluid for 0, 6, 12 and 24 h. After incubation, the FA pattern of the incubated samples was analysed using gas chromatography. Biohydrogenation is defined as disappearance of double bonds (DB) calculated from the contents of unsaturated FA. After 24‐h incubation, the DB contents of all oilseeds were reduced (p < 0.001) by 40–60%. The reduction was higher (p < 0.001) for the crushed form compared with the oil form. In addition, linseed and sunflower seed known as oilseeds with high contents of linolenic acid C18:3 c9,12,15 (LNA) and linoleic acid C18:2 c9,12 (LA), respectively, showed a higher (p < 0.001) accumulation of the BH intermediates conjugated linoleic acid (CLA, isomer C18:2 c9t11) and vaccenic acid (C18:1 t11) for the crushed form, when compared with the oil. These results suggest an inherent effect of the physical form of the assay oilseeds on in vitro BH. Changes in FA pattern during BH in vitro can be attributed to both source and physical form of the assay oilseeds. However, further investigations are warranted to ensure whether the observed in vitro effects on ruminal BH can be confirmed in vivo.  相似文献   
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