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Two entomophthoraceous species,Zoophthora radicans andEntomophthora planchoniana, were found on the yellow pecan aphid,Monellia costalis, shortly after it was introduced into Israel. This aphid is a new host forZ. radicans anywhere. The fungus was isolated in pure culture and artificially inoculated on three Dipteran species:Musca domestica, Drosophila melanogaster andCeratitis capitata, as well as on the HemipteranEmpoasca sp. from pecan. The identity ofZ. radicans and some new characters,e.g. the production of two kinds of rhizoids, are discussed. The possibility of usingM. domestica as a vector for artificial spread of the fungus, as a means of biological control of various insect pests, is advocated.  相似文献   
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Quantitative analysis of culture using millions of digitized books   总被引:1,自引:0,他引:1  
We constructed a corpus of digitized texts containing about 4% of all books ever printed. Analysis of this corpus enables us to investigate cultural trends quantitatively. We survey the vast terrain of 'culturomics,' focusing on linguistic and cultural phenomena that were reflected in the English language between 1800 and 2000. We show how this approach can provide insights about fields as diverse as lexicography, the evolution of grammar, collective memory, the adoption of technology, the pursuit of fame, censorship, and historical epidemiology. Culturomics extends the boundaries of rigorous quantitative inquiry to a wide array of new phenomena spanning the social sciences and the humanities.  相似文献   
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The dynamics of inorganic N in soil following the application of plant residues depends on their composition. We assumed that all plant materials are composed of similar components, each decomposing at a specific rate, but differ in the proportions of the various components. The NCSOIL model that simulates C and N turnover in soil was used to link the rates of residue decomposition to their composition, defined as soluble, cellulose-like and lignin-like C and N, and thereby integrate short and long-term effects of residues on available N dynamics in soil. Five plant residues in a wide range of C:N ratios were incubated in soil for 24 weeks at 30 °C, during which C and N mineralization were measured. The materials with large C:N ratios (corn, rice hulls and wheat straw) were also incubated with NH4+-N to avoid N deficiency. The residues were analyzed for total and soluble C and N. The partitioning of insoluble C and N between cellulose- and lignin-like pools was optimized by best fit of simulated C and N mineralization to measured results. The decomposition rate constants of the soluble and lignin-like pools were assumed to be 1.0 and 10−5 d−1, respectively, and that of the cellulose-like pool, obtained by model optimization against mineralization of cellulose with NH4+-N in soil, was 0.051 d−1. The optimized, kinetically defined lignin-like pool of all residues was considerably larger than lignin contents normally found in plant residues by the Van Soest procedure. Gross N mineralization of tobacco and rape residues was similar, but N recovery from tobacco was larger, because a larger fraction of its C was in the lignin-like pool. N in rice hulls, corn and wheat residues was mostly recalcitrant, yet rice hulls did not cause N deficiency, because most of its C was recalcitrant too. The soluble components of the residues had strong short-term effects on available N in soil, but the cellulose-like pool was equally important for short and medium-term effects. Soluble and cellulose-like C were 29 and 42% of total C, respectively, in corn and 7 and 50% in wheat. Maximal net inorganic N losses, measured in both residue treatments after 2 weeks, were 42 mg g−1 C applied as corn and 31 mg g−1 C applied as wheat, or 84 and 110 mg g−1 decomposed C of corn and wheat, respectively. Rice hulls immobilized N slowly, but by the end of 24 weeks all three residues immobilized 26-27 mg N kg−1 C applied. The different dynamics of N immobilization demonstrated the need to determine the decomposability of C and N rather than their total contents in plant residues.  相似文献   
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AP Foster 《Veterinary dermatology》2012,23(4):342-51, e63
This review covers cutaneous manifestations of staphylococcal infection in livestock species. CATTLE: In cattle, staphylococcal infections may present as folliculitis or as impetigo. Both may present as mild forms of a group of conditions loosely termed udder dermatitis, which has various clinical presentations and does not always involve staphylococci. GOATS: In goats, staphylococcal infection may be secondary to chorioptic mange or contagious pustular dermatitis (parapox virus infection). While Staphylococcus aureus is usually implicated, infection with Staphylococcus chromogenes and Staphylococcus hyicus have also been reported. SHEEP: Ovine staphylococcal dermatitis typically involves the head. Trauma due to the close contact of heads over feeding troughs and abrasive plants at pasture may be predisposing factors. PIGS: In pigs, the most common cause of staphylococcal skin disease is S. hyicus, although other bacteria, including Staphylococcus sciuri, Staphylococcus chromogenes and meticillin-resistant S. aureus (MRSA), have also been isolated from some cases of greasy pig disease (exudative epidermitis). DIAGNOSIS: Routine culture methods are increasingly supplemented by molecular methods to characterize staphylococci. MANAGEMENT: As commensal bacteria, staphylococcal skin infection is presumed to develop because of predisposing factors. While topical and systemic therapies can be effective, it is important to control for predisposing factors so that recurrences can be prevented. LIVESTOCK-ASSOCIATED MRSA: In recent years, MRSA strains have emerged, particularly in pigs and cattle. While they rarely cause skin disease, they do pose a significant concern for public health authorities. Studies on livestock-associated MRSA may help to progress our understanding of staphylococci in livestock, especially how they spread between animals and humans.  相似文献   
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Signs of severe otitis media in 20% of dairy calves on one farm were associated with Mycoplasma bovis infection, based on isolation from the external ear canal and nares. Affected calves seroconverted to M. bovis and no other significant bacteria were isolated. Infection was considered likely to have originated from cows in the milking herd based on evidence of seroconversion and detection of infection in a milk sample. M. bovis infection should be considered when investigating otitis problems in calves.  相似文献   
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? The concept of composting has always been rooted in a soil conservation philosophy that recognizes the role of organic matter in agriculture. The paradox has been that the recent rise in composting interest has come from the need for waste management solutions which emphasize economical and environmental alternatives, not the need for soil improvement and nutrient recycling. This review traces some early researches on the link between compost application and crop productivity and urges greater support for research that shows how compost can reduce pesticide use, improve farm economics and, in general, support the goals of sustainable agriculture.  相似文献   
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