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91.
Optimization of three parameters, temperature (25-35 degrees C), moisture content (40% (w/v)-60% (w/v) and inoculum sizes (5% (w/v)-15% (w/v) were investigated and optimized by Response Surface Methodology (RSM) for optimal mannanase production by Aspergillus terreus SUK-1. A second order polynomial equation was fitted and the optimum condition was established. The result showed that the moisture content was a critical factor in terms of its effect on mannanase. The optimum condition for mannanase production was predicted at 42.86% (w/v) initial moisture (31 C) temperature and 5.5% (w/v) inoculum size. The predicted optimal parameter were tested in the laboratory and the mannanase activity 45.12 IU mL-1 were recorded to be closed to the predicted value (44.80 IU mL-1). Under the optimized SSF condition (31 degrees C, 42.86% moisture content (w/v) and 5.5% inoculum size (w/v)), the maximum mannanase production was to prevail about 45.12 IU mL-1 compare to before optimized (30 degrees C, 50% moisture content (w/v) and 10% inoculum size (w/v)) was only 34.42 IU mL-1.  相似文献   
92.
Natural materials and plants have a long history of medical applications due to their broad range of favorable biological functions including biocompatibility, anti-bacterial, anti-oxidant and anti-inflammatory properties. Main objective of this study was to develop alginate-chitosan-hyaluronic acid (ACH) composite fibers with controlled drug release, and liquid retention properties for better moist wound healing. The dope comprising sodium alginate was extruded into calcium chloride (CaC12) coagulation bath. The developed calcium alginate fibers were then passed through a bath containing hydrolyzed chitosan and dip coated with hyaluronic acid for 24 hours. The resulting ACH composite fibers were then rinsed with deionized water and dried using acetone. These fibers were tested for tensile properties, % swelling, liquid absorption (g/g) and controlled drug release. The results concluded that ACH composite fibers can be produced by wet spinning and have adequate tensile properties, high % swelling, liquid absorption (g/g) and controlled release of hyaluronic acid for improved wound healing.  相似文献   
93.
Fish from marine and inland capture fisheries is an important food that contributes significantly to diets and health, but their contribution is somewhat overlooked in food security and poverty-related policies. Given the current numbers of malnourished people globally, there is a pressing need to consider how to better realize the potential of fish in food systems that can address malnourishment. To do so, we re-examine the fisheries literature from the perspective of food systems. Starting with nutritional needs and considering how these may be met through local food systems reveals an ongoing transformation that has implications for small-scale fisheries, as increasingly become part of globalized food systems. We describe the factors that can change the nature of production, mediate access to fish and the distribution of benefits that can lead to impoverishment. This emphasizes the governance challenges that lie at the heart of complex, contested and increasingly globalized food systems, in which actors interact to shape the systems, determining who benefits and how. We draw attention to critical issues of access, power and the values and norms that underpin efforts to manage and transform fisheries, exposing the unequal struggle to secure access that small-scale fishers and poor people must endure. We suggest a vital challenge for fisheries management is to engage with this struggle and develop policies and management measures that would enable fisheries to make positive contributions to food systems and nutritional security, while meeting global sustainable development objectives.  相似文献   
94.
Conventional open netcage systems for salmon aquaculture are under scrutiny and criticism partially because they are believed to generate adverse environmental impacts on other resource users and the surrounding environment. One alternative to preventing or miniming these impacts is to use enclosed systems. Experience indicates that these enclosed systems are technically feasible and environmentally promising, but they are economically demanding because of high capital and operating costs. Therefore, an economic analysis of open netcage and sea-bag systems for salmon aquaculture was conducted to examine the profitability of salmon aquaculture operations between these two systems. The study shows that netcage systems are more financially profitable than sea-bag systems when environmental costs are either not or only partially considered. Sea-bag systems can be financially profitable only when they produce fish that achieve a price premium. Sensitivity analyses reveal that market price has the most important impact on the profitability of both systems; changes in discount rates, fish density, feed costs, and environmental costs also have major impacts on the profitability of netcage systems. Changes in the length of the growth cycle, survival rate, and feed conversion ratio have minor impacts on the profitability of sea-bag systems.  相似文献   
95.
Background: Forests are fundamental in maintaining water supplies, providing economic goods, mitigating climate change, and maintaining biodiversity, thus providing many of the world’s poorest with income, food and medicine.Too often, forested lands are treated as "wastelands" or "free" and are easily cleared for agricultural and infrastructure expansion.Methods: In this paper, the sustainability of two forest ecosystems(state and community/private owned) was evaluated using SPOT-5 satellite images of 2005 and 2011. This study was conducted in a sub-watershed area covering 468 km2, of which 201 km2 is managed by the state and 267 km2 by community/private ownership in the Murree Galliat region of Punjab Province of Pakistan. A participatory approach was adopted for the delineation and demarcation of forest boundaries. The Geographic Object-Based Image Analysis(GEOBIA) technique was used for identification and mapping of ten Land Cover(LC) features.Results: The results show that between the years 2005 to 2011, a total of 55 km2(24 km2 in state-owned forest and 31km2 in community/private forest) was converted from forest to non-forest. The conclusion is that conservation is more effective in state-owned forests than in the community/private forests.Conclusions: These findings may help to mobilize community awareness and identify effective initiatives for improved management of community/private forest land for other regions of Pakistan.  相似文献   
96.
A new C-benzylated chalcone from Desmos chinensis   总被引:1,自引:0,他引:1  
A new C-benzylated chalcone was isolated from the leaves of Desmos chinensis. Its structure was established as 2',4'-dihydroxy-3'-(2,6-dihydroxybenzyl)-6'-methoxychalcone on the basis of spectroscopic data.  相似文献   
97.
The effect of various flavonoids, lectins and phenyl β-d-glucoside on larval survival, weights and the activities of digestive (total serine protease and trypsin) and detoxifying [esterase and glutathione-S-transferase] enzymes of Helicoverpa armigera larvae at 5 and 10 days after treatment (DAT) was studied through diet incorporation assay. Flavonoids (quercetin, cinnamic acid, caffeic acid, chlorogenic acid, catechin, trihydroxyflavone, gentisic acid, ferulic acid, protocatechuic acid and umbelliferone) were incorporated in artificial diet at 100, 500 and 1000 ppm, lectins: groundnut leaf lectin (GLL), concavalin (ConA) and phenyl β-d-glucoside at 2.5 and 5 μg mL?1. Flavonoids such as chlorogenic acid, caffeic acid and protocatechuic acid at 1,000 ppm were more toxic to H. armigera larvae at 10 DAT than quercetin, catechin, cinnamic acid, trihydroxyflavone, gentisic acid, ferulic acid and umbelliferone. Larval growth and development were significantly reduced in H. armigera larvae fed on a diet with GLL and ConA at 5 μg mL?1 compared to the larvae fed at 2.5 and 1.25 μg mL?1 concentrations. The enzyme activities of the larvae were significantly reduced in flavonoid-treated diets. The flavonoids such as chlorogenic acid, caffeic acid, gentisic acid, trihydroxyflavone, catechin and protocatechuic acid, and lectins, GLL and ConA can be utilized in insect control programs.  相似文献   
98.
In two consecutive seasons, forage rape (Brassica napus L.) plants were exposed to short periods (240°C hr) of heat stress (30°C day/25°C night) during seed filling (80% seed moisture content = S1), at physiological maturity (50% seed moisture content = S2) and at both S1 plus S2 (=S3) in a Biotron before being returned to the field until seed harvest. Seeds were hand harvested at 14% seed moisture content and their quality assessed by measuring germination, seed vigour (using the accelerated ageing and conductivity tests) and seed mass (as determined by thousand seed weight). Heat stress at both S1 and S2 caused a small (<10%) but significant reduction in germination in both seasons. There was a significant heat stress timing interaction in the first but not the second season. Reductions in germination were a result of increased abnormal seedling production not seed death. All three heat stress treatments significantly reduced seed vigour, with S3>S2>S1. Seed mass was reduced by heat stress at S1 but not at S2. Variable seed vigour in high‐germinating New Zealand‐produced forage rapeseed lots is most likely explained by short periods of heat stress during seed development.  相似文献   
99.
ABSTRACT

Climate change is imposing high temperature resulting in prolonged drought episodes and shrinking of fresh water resources across the globe. In this scenario, even drought tolerant crops like quinoa are also losing significant yield. However, this study was planned to investigate the impact of drought on quinoa at critical growth stages and bacterial inoculation to improve drought tolerance. Drought was imposed by maintaining 25% pot water holding capacity (PWC) at multiple leaf, flowering, and seed filling stage (DSFS), while 80% PWC was considered as control. Three strains of plant growth promoting rhizobacteria (PGPR) named as: Bacillus licheniformis, Pseudomonas fluorescens, and Azospirillum brasilense were inoculated with quinoa seeds before sowing with respect to drought treatments. PGPR inoculation mitigated the drastic effects of drought by improving crop growth, net assimilation rate, water use efficiency, leaf chlorophyll, and phenolic contents, all of these ultimately contributed to improvement in grain yield and its contributing attributes. Moreover, PGPR markedly improves the grain quality attributes including protein, phosphorus, and potassium contents. Principal component analysis linked the different scales of study and demonstrated the potential of physio-biochemical traits to explain the quinoa yield variations under drought condition with response to PGPR inoculation. Among different PGPR, A. brasilense was found most effective both under normal and drought conditions. Overall, DSFS has more detrimental effects among critical growth stages of quinoa and A. brasilense can be used as a shotgun tactic to ameliorate drought stress in quinoa.  相似文献   
100.
Zinc (Zn) deficiency is often associated with calcareous soils throughout the world, whereas application of Zn not only enhances biological yield but exhibits significant interactions with nutrients. Hence, a two-year field experiment was performed in 2004 and 2005 to assess the crop Zn requirements as well as nutrient interactions in cotton. The present study followed a randomized complete block design with five Zn levels: 0.0, 5.0, 7.5, 10.0, and 12.5 kg Zn as ZnSO4.7H2O. The biological yield of cotton increased progressively with increasing Zn rates. In general, cotton yield was higher in 2005 over 2004. Interestingly, Zn fertilization resulted in increased accumulation of nitrogen (N), potassium (K), boron (B), and Zn, whereas decreased the phosphorus (P), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), and manganese (Mn) (p ≤ 0.05) uptake by cotton. The enhanced macronutrients accumulation in cotton by Zn application improved the cotton yield. In conclusion, biological yield and nutrient composition of the cotton plant are greatly influenced by Zn supply under irrigated environments.  相似文献   
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