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71.
A.?El HadramiEmail author D.?Kone P.?Lepoivre 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(3):241-254
The black leaf streak disease (BLSD), caused by Mycosphaerella fijiensis, is the most destructive disease of bananas and plantains around the world. Breeding for resistance is the most promising
strategy to fight this disease especially in small farmer plantations. Mycosphaerella fijiensis produces many phytotoxins such as juglone, which can be used, jointly with field and inoculations under controlled conditions,
for screening banana cultivars for BLSD-resistance. This non-host specific phytotoxin has been shown to act on chloroplasts
and disturbs the proton electrochemical gradient across the plasmalemma membrane. Moreover, an involvement of the oxidative
burst during the interaction has been suggested. The present study was carried out using two cultivars that differed for either
their juglone-responses or their resistance to BLSD (cv. Grande Naine susceptible to BLSD and juglone and cv. Fougamou partially
resistant to BLSD and highly tolerant to juglone). The production of active oxygen species (AOS) and the enhancement of the
enzymatic and/or non-enzymatic AOS-scavenging systems were investigated after treatment of the two cultivars with juglone.
The time-course of AOS-production and AOS-scavenging was shown to be the key difference between these two tested cultivars
after treatment with juglone. Thus, an early release of AOS (O2− radical and H2O2) and a quick stimulation of a preferment anti-oxidant system (superoxide dismutases, catalases, and peroxidases) was observed
for cv. Fougamou as compared to cv. Grande Naine for which a late and weak generation of AOS accompanied by a late stimulation
of the anti-oxidant systems were detected. 相似文献
72.
73.
S. M. El Hassan M. S. M. A. Harbi M. I. Abu Bakr 《Veterinary research communications》1984,8(1):65-67
Goats that had been inoculated with the causal organism of contagious, caprine pleuropneumonia and treated, within a few days, with oxytetracycline or tylosin, were less severely affected than infected, untreated control goats. However, 20% of treated cases remained infective and were, presumably, capable of transmitting the infection. 相似文献
74.
Gutiérrez-Martín CB del Blanco NG Blanco M Navas J Rodríguez-Ferri EF 《Veterinary microbiology》2006,115(1-3):218-222
A total of 229 Spanish Actinobacillus pleuropneumoniae isolates recovered from diseased pigs with pleuropneumonia from 1997 to 2004 was tested for their susceptibility to 11 antimicrobials in a broth microdilution method. All the isolates were susceptible to florfenicol and most of them to cephalothin; however, a high rate of resistance was observed to tetracycline. A bimodal or multimodal distribution of isolates over the MIC range were observed for penicillins, tetracycline, trimethoprim, sulfisoxazole and nalidixic acid, suggesting the development of acquired resistance. Eight resistance patterns were established, and 21.1% of the isolates were resistant to at least two antimicrobials. In addition, a considerable increase in the resistance to tetracyclines was observed during the last decade in Spain, when compared with other A. pleuropneumoniae strains isolated during 1987-1988 (Gutiérrez, C.B., Píriz, S., Vadillo, S., Rodríguez Ferri, E.F., 1993. In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents. Am. J. Vet. Res. 54, 546-550); this finding was also observed for gentamicin in minor percentage. 相似文献
75.
del Río ML Navas J Martín AJ Gutiérrez CB Rodríguez-Barbosa JI Rodríguez Ferri EF 《Veterinary research》2006,37(1):49-59
Bacteria have evolved a set of highly specialized proteins to capture iron in iron-depleted environments. The acquisition and uptake of iron present in the extracellular milieu of eukaryotic organisms is indispensable for the growth and survival of microbial pathogens in the course of infection. Haemophilus parasuis is the causative agent of Gl?sser disease, which is responsible for considerable financial losses in pig-rearing worldwide. To gain insight into the mechanisms involved in siderophore-mediated iron uptake in H. parasuis, genes in the H. parasuis ferric hydroxamate uptake (Fhu) region were amplified in the work being reported here. As has been described in A. pleuropneumoniae, an Fhu genomic region was also present in H. parasuis, being composed of four potential consecutive open reading frames (ORF) designated as fhuC, fhuD, fhuB, and fhuA, respectively. By immunoblotting, using a cross-reactive polyclonal antibody raised against Actinobacillus pleuropneumoniae FhuA protein, it was demonstrated that this protein was constitutively expressed in H. parasuis and its level of expression was not modified under conditions of restricted iron availability. This is the first report describing the presence of the fhu genes in H. parasuis. Our results indicate that FhuA protein expression is not affected under iron-restricted conditions, however, it is one of the targets of the humoral immune response. 相似文献
76.
Quill mites (Gabucinia bicaudata) and lice (Struthiolipeurus struthionis) may infest ostrich feathers, resulting in skin damage, pruritus and excessive feather preening and loss. Four different feather types (prime white, femina extra wide, femina class 1, and femina short; n = 10) were collected. The quill mites and lice were removed with fine forceps, studied using a photographic optical microscope and counted microscopically at x 100 magnification following collection by sedimentation. They were placed in separate Petri dishes containing lactophenol solution and examined (x40 magnification). Anatomical features are described. The density of quill mites in all feather types of both wings was higher than that of the lice. There was no significant difference between the counts of both arthropods on the left wing and the right wing, respectively, except for the femina class 1 quill mites (P = 0.01). The femina extra wide feathers were a preferred habitat in both wings. Large standard deviations (quill mites left wing: 73 +/- 8; quill mites right wing: 69 +/- 7) suggested variations in the degree of migration between feather shafts or as a response to escape preening. It is recommended that ostriches be treated with an oral preparation of Ivermectin administered per os at a dosage rate of 0.2 mg/kg at 30-day intervals for quill mites, and with a 1-5 % Malathion dust at 14-day intervals for lice. 相似文献
77.
Hamid ME Alla KM Ahmed SS El Shiekh AE Ibrahim KE 《Journal of the South African Veterinary Association》2006,77(2):90-91
We describe a rare case of a concurrent demodectic and sarcoptic mange in a 2-year-old heifer in Khartoum, Sudan. The lesions were massive lumps of granulomatous tumour-like dermatitis with thick, nodular folds mainly covering the head, neck and shoulders. Histopathological examination of the lesions revealed the presence of both Demodex bovis and Sarcoptes scabiei. The animal died regardless of the anti-parasitic treatment it received. 相似文献
78.
David Maxwell Suckling Lloyd D Stringer Joshua E Corn Barry Bunn Ashraf M El‐Sayed Robert K Vander Meer 《Pest management science》2012,68(12):1572-1578
BACKGROUND: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E‐α‐farnesene (91% purity) was prepared, and disruption of worker trail orientation was tested using an ethanol‐based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail‐following behaviour was recorded by overhead webcam and ants digitised before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm?2). RESULTS: Ants preferred 110 ng cm?1 over 11, 1.1 and 0.11 ng cm?1 for trail following. Within seconds of presentation of 1600 ng cm?2, the highest dose tested, trail disruption was observed. Disruption was evident as reduced arrival success and reduction in the trail integrity statistic (r2), as well as increased deviation from the trail (deg). The distribution of walking track angles was also flattened. CONCLUSIONS: The feasibility of using aerosol for delivery of trail pheromone was demonstrated, but the need for high purity combined with the difficulty of commercial supply makes this technique impractical. However, the commercial production of Z,E‐α‐farnesene of high purity by industrial biotechnology or from (E)‐nerolidol may be possible in future, which would facilitate further development of trail pheromone disruption of S. invicta. Copyright © 2012 Society of Chemical Industry 相似文献
79.
A cross-sectional survey was conducted in Sudan to determine sero-prevalence and risk factors associated with Neospora caninum infection in non-vaccinated dairy herds and to assess importance of the disease. Blood samples were collected from a total
of 262 animals from 25 herds. Sera were tested for antibodies against N. caninum using ELISA test. The prevalence rates of N. caninum antibodies in cattle were high both at herd level (44%) and at individual animal level (10.7%). Herd level infection rates
were similar in Khartoum State (43.7%) and at Gazira States (44.4%). The overall prevalence rates were higher (16.1%) in Gazira
State than in Khartoum State (9%) but with no significant variation. The sero-prevalence at individual animal level was significantly
higher (p < 0.05) in animals with history of abortion (12.8%) than in apparently healthy animal (11.3%), animal with history of infertility
(8.1%), or neonatal death of calves (4.3%). In addition, significantly higher (P < 0.05) sero-prevalence was observed in samples collected during the rainy season (6.87%) than winter (3.05%) or summer (0.76%).
However, no significant differences in sero-prevalence due to locality, animal breed, sex, and age were observed (p > 0.05). This preliminary study reveals for the first time the existence of natural N. caninum infection in Sudan. Also, the findings of the present study indicated that this disease is highly prevalent in two major
areas of dairy production in the country, and this calls for control strategy to be implemented. 相似文献
80.
Mustapha Bakry Mohammed S. Lamhamedi Jean Caron Hank Margolis Abdenbi Zine El Abidine M’Hammed Bellaka Debra C. Stowe 《New Forests》2012,43(3):267-286
The morpho-physiological quality of seedlings is negatively affected by the wide scale use of forest soils as substrates in
developing countries. With the objective of finding long-term sustainable supply of growing media, compost was produced from
shredded branches of three fast growing species (Acacia cyanophylla (AA), Acacia cyclops (AS) and Eucalyptus gomphocephala (EG). The composting process covered three different periods over the course of a year. Pile temperatures were monitored daily
and the composts were routinely sampled and analyzed for 19 chemical variables. Although composting is feasible year-round
in arid climates, compost produced in the humid cool conditions of autumn, winter and early spring reaches the maturation
phase more quickly than compost produced under hot, dry summer conditions. It also requires less turning and water. The evolution
of the composting process and quality of the final product can be assessed using three chemical variables (C/N, pH, EC). Seed
germination rates in the three types of compost were similar to that in a peat:vermiculite substrate and vigorous high quality
seedlings were produced in the two acacia composts. However, compost-grown seedlings had significantly smaller shoots and
root systems than those produced in peat substrate. Principal components analyses showed that the quality of a compost-based
substrate is reproducible and that its final chemical composition can be predicted from its raw organic materials. The EG composts had higher pH than the acacia composts, whereas the AA and EG composts were higher in mineral salts than the AS. 相似文献