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41.
Airborne laser scanner (ALS)-based forest inventory method usuallyadopt a laser canopy height distribution approach in which forestcharacteristics are predicted using measures such as percentilesof the distribution of laser canopy heights across a fixed area.The method requires a ground-truth sample of accurately measuredfield plots. One possibility for reducing the costs lies inthe use of existing field plots for ground-truth purposes. Themost obvious alternative in Finland would be to use truncatedangle count sample plots of the National Forest Inventory ormore locally data of checking of inventory by compartments.Due to the lack of suitable angle count ground-truth data andcorresponding laser data, we tested this possibility using dataon fixed-area sample plots, in which tree locations were simulated.The trees for a truncated angle count sample plot were thenchosen and the resulting data together with the characteristicsof an ALS-based canopy height distribution were used to constructregression models to predict stem volume, basal area, stem number,basal area median diameter and height. The accuracy of the standattributes was found to be almost as good as in the case ofmodels of fixed-area plots.  相似文献   
42.
1. Two experiments were conducted to examine the effect of feeding higher supplemental vitamin E (VE) concentrations on male reproductive variables, fertility and hatchability of quails. 2. In experiment 1, sixty 5-week-old male quails, reared in individual cages, were fed male breeder diets supplemented with 0, 75, 150, 225 or 300 IU alpha-tocopherol acetate/kg. At 10 weeks, observations on cloacal gland size, foam production, testes weight and blood samples for testosterone estimation were taken. 3. In experiment 2, 50 male and 50 female cage-reared quails (5 weeks old) were fed male breeder and layer rations, respectively, supplemented with 0, 75, 150, 225 or 300 IU/kg. At 13 weeks, 9 different mating pairs (5 pairs/group) were formed. Group 1 contained one control male and one control female in each of 5 pens. In groups 2 to 5, control males were paired with females on supplements of 75, 150, 225 or 300 IU/kg. In groups 6 to 9, control females were paired with males on supplements of 75, 150, 225 and 300 IU/kg. During subsequent adaptation and egg collection periods, each of 10 d, control layer ration was fed to all groups. All the eggs laid during the 10-d egg collection period were incubated artificially to estimate fertility and hatchability. The trial was repeated at 15 weeks. 4. Adult male quails receiving moderate supplemental VE (75 and 150 IU/kg) had a higher cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone than quails fed on either VE-deficient or more highly supplemented diets (225 and 300 IU alpha-tocopherol acetate/kg). 5. It was concluded that a supplement of 75 IU VE/kg in maize/soybean diet could provide the best reproductive performance of male breeder quails. Cloacal gland index, quantity of foam secretion, testicular weight and plasma testosterone can serve as indirect indicators of testicular activity and fertilising ability in quails. Supplemental VE did not affect the fertility and hatchability of male and female Japanese quails.  相似文献   
43.
One new glycoside derivative from syringic acid and one new phenol glycoside, curculigoside E (1) and orchioside D (2), were isolated and characterized from the rootstock of Curculigo orchioides collected in the Nawalparasi District (Nepal). The structures of the new isolated compounds were elucidated by means of spectroscopic methods such as 1D, 2D NMR and MS.  相似文献   
44.
Soil samples were collected from rhizosphere of litchi-growing areas of North-Western Himalayan Region (NWHR) of India, for finding qualitative and quantitative differences in arbuscular mycorrhizal (AM) fungi and Azotobacter chroococcum. These samples were taken from plants being grown in different cultivation types namely, weed control with weedicides or tillage; orchard floor either clear or with cover crops; intercropping with cereals and legumes. Qualitative and quantitative differences were noticed with different cultivation types and a marked reduction in the AM fungi was observed in orchards where chemicals were used for weed control and intensive farming system was used on the orchard floor. AM fungi were generally abundant in the soils with range pH 5.5–6.6. Among different AM fungi retrieved from the soils, Glomus spp. was most dominant. Fifteen AM fungal species were isolated, identified and characterized and along with their ability to colonize the roots. In the soil samples, a marked variation in viable bacterial count of A. chroococcum was also noticed due to varied physico-chemical characteristics of the orchard soils. The changes in AM fungal species composition can be attributed to changes in soil chemical properties resulting from cultural practices such as ploughing, application of chemical fertilizers and weedicides. An experiment was also conducted to study the comparative efficacy of four dominant and frequently occurring indigenous AM species namely, Glomus fasciculatum (Thaxter sensu Gerdemann), G. magnicaulis (Hall), G. mosseae (Nicol. & Gerd.), Gigaspora heterogamma (Nicol. & Gerd.) and two A. chroococcum strains viz., AZ1 and AZ2 singly and in dual combination to evaluate their effect in air-layers system. Dual inoculation of G. fasciculatum and AZ1 increased total root length of air-layered shoots by 81.39% over uninoculated control. These studies indicated that indigenously isolated AM fungal species and A. chroococcum strains can be used for air-layering for better adaptation under specific agro-climatic and ecological zone conditions.  相似文献   
45.
For marine structural applications which poses significant challenges to the choice of materials due to presence of corrosive seawater, polymer matrix based fiber reinforced composites are increasingly becoming the material of choice. However the performance properties of composites are greatly influenced by the moisture absorbed by the composite. In the current study, the long term performance is assessed by determining the amount of moisture absorbed and the reduction of mechanical properties over 12 months in a simulated sea-water environment at different temperatures. Three commonly used thermoset resins with different chemistry such as unsaturated polyester (USP), epoxy resin (EP) and vinylester (VE) are chosen. The effect of fiber reinforcement on the long term performance is investigated. A suitable method for manufacturing glass reinforced composite with good interfacial bonding and high volume fraction is also developed in current study. It is observed that vinylester plaques and composites absorb lesser moisture compared to USP and Epoxy systems resulting in lesser reduction in flexural strength and making the best performing among polymers studied. It is also found that sea-water diffusion into the composite follows non-Fickian behaviour and diffusion relaxation model fits well with the experimental data and corresponding model parameters are evaluated.  相似文献   
46.
Journal of Crop Science and Biotechnology - Buckwheat is minor crop of Nepal. Due to their multiple uses, short growing periods, high nutritional and medicinal values, wide adaptability has become...  相似文献   
47.
Site-specific delivery of fertilizer is a useful tool to address differences in crop need. Modern systems with wirelessly networked sensors and valves allow multiple hydrozones to be created more easily than traditional wired systems. This allows irrigation and fertigation rates to be varied across small portions of a field. However, fertigation to multiple hydrozones with different fertilizer requirements may be complex if each zone cannot be fertigated in an independent set. Instead, it might be necessary to operate several fertigation zones simultaneously. This raises a concern over the ability to deliver fertilizer uniformly within each zone. Four fertigation strategies were tested. The conventional method was to fertigate multiple hydrozones at different times. Three site-specific strategies were considered, involving overlapping fertigation phases in multiple hydrozones. Fertilizer distribution uniformity tests were conducted with a 64-emitter drip line to determine which strategy gave the most uniform distribution of fertilizer within a hydrozone. All fertigation techniques performed well, with fertilizer distribution uniformities between 0.88 and 0.96. Selection of the optimum site-specific fertigation strategy will depend on crop needs, scheduling limitations, and system design parameters such as emitter type, fluid travel time, and slope. Similar to conventional fertigation, the main factor in fertilizer distribution uniformity for this study was drip emitter variability. In the presence of sloped terrain, the site-specific control strategy that involved a delay between fertilizer injection and flushing had the least uniform fertilizer application.  相似文献   
48.
The Kathmandu valley, nestled in the midst of the mighty Himalaya, is one of the worth visiting places in the world. Unplanned urbanization, increasing population, polluting vehicles and industries have started degrading the environment in the valley. Centralized development activities in the last two decades resulted in undesirable environmental change. If the current trend continues, valley will loose its importance. Realizing the importance of healthy environment, His Majesty's Government of Nepal has formed the Environment Protection Council under the chairmanship of Prime Minister to formulate environmental planning and policies. Over two dozen active NGOs are involved in environmental awareness and management in the Kathmandu valley. Some major steps have been undertaken by GOs and NGOs. Present paper deals with the state of pollution, efforts made to minimize it, and major actions/strategies for preventing pollution in the Kathmandu valley.  相似文献   
49.
Journal of Plant Diseases and Protection - The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), a polyphagous lepidopteran pest that is native to tropical and sub-tropical America has...  相似文献   
50.
Summary Nepal is rich in indigenous wild and landrace plant genetic resources for agronomic, horticultural, forestry, or medicinal uses, but much of this germplasm remains uncollected and awaits economic development. We list 485 entries (species, or genera for ornamental plants) in 14 categories, and compare these to existing germplasm collections in Nepal and the United States to highlight collection and conservation needs. To help plant plant collecting, we outline the key botanical and logistical data and legal framework for planning field work in Nepal.  相似文献   
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