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31.
The heavy metal contents of some solid wastes produced in residential areas, a market, a cafeteria and the composts in lbadan, Nigeria, were measured. The solid wastes produced in low density areas with higher per capita income showed higher levels of heavy metals. The cafeteria waste showed low levels of some of these metals. The significance of the heavy metal status on Nigerian environment is discussed.  相似文献   
32.
Thirteen essential oils recovered by steam distillation from Indian herbs were analyzed for their chemical compositions using GC and GCMS. The antifungal activity against plant and Food mold rot were examined in vitro using poison food technique. The essential oil from cymbopogan exhibited control over all the plant and food mold rot tested. The bioactive compound in the oil and its minimum inhibitory concentration were determined using TLC bioautography.  相似文献   
33.
Mastitis (intramammary inflammation) caused by infectious pathogens is still considered a devastating condition of dairy animals affecting animal welfare as well as economically incurring huge losses to the dairy industry by means of decreased production performance and increased culling rates. Bovine mastitis is the inflammation of the mammary glands/udder of bovines, caused by bacterial pathogens, in most cases. Routine diagnosis is based on clinical and subclinical forms of the disease. This underlines the significance of early and rapid identification/detection of etiological agents at the farm level, for which several diagnostic techniques have been developed. Therapeutic regimens such as antibiotics, immunotherapy, bacteriocins, bacteriophages, antimicrobial peptides, probiotics, stem cell therapy, native secretory factors, nutritional, dry cow and lactation therapy, genetic selection, herbs, and nanoparticle technology-based therapy have been evaluated for their efficacy in the treatment of mastitis. Even though several strategies have been developed over the years for the purpose of managing both clinical and subclinical forms of mastitis, all of them lacked the efficacy to eliminate the associated etiological agent when used as a monotherapy. Further, research has to be directed towards the development of new therapeutic agents/techniques that can both replace conventional techniques and also solve the problem of emerging antibiotic resistance. The objective of the present review is to describe the etiological agents, pathogenesis, and diagnosis in brief along with an extensive discussion on the advances in the treatment and management of mastitis, which would help safeguard the health of dairy animals.  相似文献   
34.
Study was conducted to find out the comparative susceptibility of fingerlings of seven species of carps (Labeo fimbriatus, L. rohita, L. calbasu, Catla catla, Ctenopharyngodon idella, Cyprinus carpio and Hypophthamichthys molitrix) grown under both mono and polyculture to Lernaea cyprinacea infection. Under monoculture, C. carpio, L. rohita and L. calbasu, did not acquire Lernaea infection and were thus considered resistant, whereas C. idella, H. molitrix, C. catla and L. fimbriatus were susceptible. Even challenge with higher infective doses of copepodids under monoculture did not result in infection in the resistant fish species. The resistance of L. rohita and C. carpio to Lernaea infection under monoculture was not sustained when these two fish species were maintained in polyculture along with susceptible fish species. Labeo calbasu, even under polyculture, however, did not acquire Lernaea infection indicating that this fish species is the most resistant and least preferred host for this parasite. Similarly, C. carpio, L. rohita and L. calbasu when grown together in polyculture and exposed to a higher infective dose (120 copepodids/fish) also did not develop the infection. The possible reasons for differences in susceptibility shown by these carp species in monoculture and the loss of resistance by rohu and common carp while in polyculture with susceptible species are discussed. The ability of resistant fish species to prevent establishment of anchor worms on them under monoculture can be utilized to control this parasitic infection commonly encountered in culture ponds.  相似文献   
35.
Although serologic data indicate horses in N. America are exposed to a variety of leptospiral serovars, abortion is almost always associated with Leptospira interrogans serovar Pomona type kennewicki. A variety of wildlife including raccoons, white tailed deer, striped skunks, opossums, and red and grey foxes have been shown to host serovar Pomona and have therefore been suspect as sources of infection for pregnant mares. The aim of the present study was to examine genetic diversity in serovar Pomona type kennewicki in wildlife and in aborting mares. Our approach utilized PCR that targeted tandem repeats at the VNTR - 4 locus and a 1235 bp 5'-sequence of the lk73.5 (sph2) and adjacent upstream sequence unique to serovar Pomona. All isolates/specimens of equine origin in 1992 and 2008 yielded amplicons of 1235 and 595 bp, whereas 14 isolates/specimens from wildlife yielding a 1235 bp amplicon characteristic of serovar Pomona produced amplicons of 1300, 550 bp (3), 1300 bp (10), or 595 bp (6) with the VNTR - 4 primer set. Wildlife therefore hosted at least three different genetic variants of type kennewicki including the genetic variant that predominated in aborting mares. The data are consistent with other studies indicating specific genetic variants of type kennewicki show a strong tendency to be associated with a specific host. Levels of antibody in wildlife sera reactive with rLk73.5, rLig130 and sonicate of type kennewicki were poorly correlated with PCR data, although rLk73.5 was superior to rLig130 in detection of antibody responses. PCR is therefore a more reliable tool for studies of wildlife reservoirs of Leptospira sp. than serologic surveillance that targets host induced proteins or LPS-rich sonicate.  相似文献   
36.
Race non-specific resistance to rust diseases in CIMMYT spring wheats   总被引:1,自引:0,他引:1  
Rust diseases continue to cause significant losses to wheat production worldwide. Although the life of effective race-specific resistance genes can be prolonged by using gene combinations, an alternative approach is to deploy varieties that posses adult plant resistance (APR) based on combinations of minor, slow rusting genes. When present alone, APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4?C5 such genes usually result in ??near-immunity?? or a high level of resistance. Although high diversity for APR occurs for all three rusts in improved germplasm, relatively few genes are characterized in detail. Breeding for APR to leaf rust and stripe rust in CIMMYT spring wheats was initiated in the early 1970s by crossing slow rusting parents that lacked effective race-specific resistance genes to prevalent pathogen populations and selecting plants in segregating populations under high disease pressure in field nurseries. Consequently most of the wheat germplasm distributed worldwide now possesses near-immunity or adequate levels of resistance. Some semidwarf wheats such as Kingbird, Pavon 76, Kiritati and Parula show high levels of APR to stem rust race Ug99 and its derivatives based on the Sr2-complex, or a combination of Sr2 with other uncharacterized slow rusting genes. These parents are being utilized in our crossing program and a Mexico-Kenya shuttle breeding scheme is used for selecting resistance to Ug99. High frequencies of lines with near-immunity to moderate levels of resistance are now emerging from these activities. After further yield trials and quality assessments these lines will be distributed internationally through the CIMMYT nursery system.  相似文献   
37.
Sedimentation filling space beneath ice shelves helps to stabilize ice sheets against grounding-line retreat in response to a rise in relative sea level of at least several meters. Recent Antarctic changes thus cannot be attributed to sea-level rise, strengthening earlier interpretations that warming has driven ice-sheet mass loss. Large sea-level rise, such as the approximately 100-meter rise at the end of the last ice age, may overwhelm the stabilizing feedback from sedimentation, but smaller sea-level changes are unlikely to have synchronized the behavior of ice sheets in the past.  相似文献   
38.
39.
Seeds of two coastal sand dune wild legumes, Canavalia cathartica and Canavalia maritima from the west coast of India were analyzed for their nutritional and antinutritional properties. The seeds contained 35.5 and 34.1% crude protein, 52.8 and 50.5% crude carbohydrates, 1.3 and 1.7% crude lipids and 3.1 and 3.5% ash content, respectively. Among the minerals, potassium was the highest followed by phosphorus. Globulins and albumins constituted the major seed proteins of both plants. Most of the essential amino acids were at adequate levels. Although the crude lipids were below 2%, the unsaturated fatty acids were high. Seeds did not contain tannins and trypsin inhibitors. The levels of total phenolics were low, but showed high hemagglutination activity. The nutritional properties of these seeds have been compared with other Canavalia spp. and wild unconventional or tribal legumes. Overall, the study results suggest that the seeds of C. cathartica and C. maritima possess potential nutritive value particularly higher protein, essential amino acids and low levels of antinutritional factors. These wild legumes are adapted to low nutrient, high saline and drought conditions of the coastal sand dunes; their conservation and domestication are warranted as potential alternative sources of protein.  相似文献   
40.
Nutrient composition of the manure of four pill millipedes (Arthrosphaera dalyi, A. davisoni, A. fumosa and A. magna) inhabiting in semi-evergreen forests and plantations of the Western Ghats of Southwest India was evaluated. The quantity and quality of fecal pellets differed between millipedes and their habitats (forest and plantation). Organic carbon content in manure was lower in plantations than in forests, while nitrogen content was elevated in plantations. The carbon to nitrogen (C/N) ratio of manure was lower in plantations compared to forests. The phosphorus content in manure was elevated in plantations in all except for A. dalyi. Calcium content of manure was increased in plantations than in forests. The contents of magnesium, potassium and phenolics in manure showed varied results. The mass of fecal pellets was correlated only with volume in forests (r=0.882; p < 0.01) and pH in plantations (r=0.616; p < 0.05), while the volume of fecal pellets was correlated with nitrogen content in forests (r=0.751; p < 0.01) and calcium in plantations (r=?0.619; p < 0.05). The conductivity was positively correlated with phosphorus and potassium, while magnesium was negatively correlated in forests as well as plantations. Potassium and magnesium were negatively correlated in forests (r=?0.920; p < 0.001) and plantations (r=0.692; p < 0.05). Overall, the physicochemical characteristics and nutrient composition of fecal pelets differed between millipedes as well as habitats. The low carbon to nitrogen ratio and the increased nitrogen, phosphorus and calcium content in the manure of millipedes inhabiting in plantations indicates possibilities for successfully employing them for in situ composting of forest or plantation residues.  相似文献   
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