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111.
Mycoplasma synoviae infection occurs worldwide in commercial poultry flocks and may result in severe economic losses. The prevalence of this mycoplasma in standard layers older than 60 weeks was studied in a French department and the characteristics of infected or free flocks were compared. The genomic profiles of isolates from 36 infected flocks were studied by pulsed-field gel electrophoresis and random amplified polymorphic DNA methods in order to investigate possible routes of transmission. The minimum inhibitory concentrations of antibiotics were determined. Results showed that infection was more frequent in multi-age farms. Egg production and mortality of infected flocks were respectively lower and higher than in non-infected flocks but the differences were not statistically significant. The genomic profiles of isolates were quite homogeneous, a feature which does not facilitate the understanding of routes of transmission. All isolates were susceptible to tetracyclines, macrolides (except erythromycin), spectinomycin and fluoroquinolones. 相似文献
112.
W. R. Webster Corinne K. Dimmock† P. K. O'Rourke † P. J. Lynch § 《Australian veterinary journal》1978,54(7):345-348
SUMMARY Iron supplementation of piglets with oral galactan given as a single dose within 24 hours of birth was evaluated in a series of on farm trials. The growth rate of piglets receiving this treatment was faster than that of piglets receiving single injections of iron dextran or iron galactan at 3 days of age, or ferrous sulphate crystals orally at weekly intervals. Mean values for red cell parameters of oral iron galactan supplemented piglets at 2 to 4 weeks of age were lower than those of injected piglets but there was no clinical evidence of anaemia in any of the piglets. 相似文献
113.
J. Gordon ArbuckleJr. Corinne Valdivia Andrew Raedeke John Green J. Sanford Rikoon 《Agroforestry Systems》2009,75(1):73-82
Land tenure has long been considered a critical factor in determining the adoption and long-term maintenance of agroforestry
practices. Empirical evidence from non-US settings has consistently shown that secure land tenure is positively associated
with agroforestry adoption. In the US, over 40% of private agricultural land is farmed by someone other than the owner. Given
the importance of land tenure in agroforestry decisions in other countries and the magnitude of non-operator landownership
in the US, there has been surprisingly little focus on land tenure in the temperate agroforestry literature. Using data from
a 1999 survey in Missouri, this study explores factors associated with non-operator landowner interest in agroforestry. Results
suggest that differences in farming orientation are linked to interest in agroforestry. Closer ties to farming, stronger financial
motivations for landownership, and higher proportion of land planted to row crops were negatively related to interest in agroforestry
among non-operator landowners. Environmental or recreational motivations for landownership and contacts with natural resource
professionals were positively associated with interest in agroforestry. These results, consistent with earlier qualitative
research suggesting that farm operators who have a strong “conventional farming identity” were less interested in agroforestry,
point to a divide between landowners for whom environmental and recreational values play an important role in ownership motivation
and those for whom financial considerations take precedence. The findings imply that agroforestry development programs in
the US should take non-operator landowners and their farming and ownership orientations into account when designing research
and outreach efforts.
相似文献
J. Gordon Arbuckle Jr.Email: |
114.
William Piang-Siong Pascale de Caro Corinne Lacaze-DufaureAlain Shum Cheong Sing William Hoareau 《Industrial Crops and Products》2012,35(1):203-210
Sugar cane is a crop which generates large amounts of biomass and a juice rich in high-value natural molecules. After extracting sugar from the juice, the recovering of various compounds such as organic acids contained in molasses could contribute to increase the competivity of the sugar industry. Therefore, according to the biorefinery approach, we propose to study the chemical conversion of one of these acids, the aconitic acid, by esterification reactions. A new series of aconitate esters have been synthesized by combining aconitic acid and alcohols from natural origin. The effects of experimental conditions have been investigated and have shown that the type of catalysis has a significant effect on the selectivity. Kinectics have thus been performed to determine the best conditions to synthetize enriched compositions in esters. Homogeneous catalysis generates the highest yield in triester. Heterogeneous catalysis (macroporous resins) is prefered for the production of monoesters while catalysis assisted by ionic liquid is adapted to prepare mainly diesters. Green indicators have been discussed according to the calculations performed. The resulting polyfunctional esters are totally biosourced molecules and have a great potential as bioproducts for different applications. 相似文献
115.
Vitour D Guillotin J Sailleau C Viarouge C Desprat A Wolff F Belbis G Durand B Bakkali-Kassimi L Breard E Zientara S Zanella G 《Veterinary research》2011,42(1):18
Since its introduction into northern Europe in 2006, bluetongue has become a major threat to animal health. While the efficacy of commercial vaccines has been clearly demonstrated in livestock, little is known regarding the effect of maternal immunity on vaccinal efficacy. Here, we have investigated the duration and amplitude of colostral antibody-induced immunity in calves born to dams vaccinated against bluetongue virus serotype 8 (BTV-8) and the extent of colostral antibody-induced interference of vaccination in these calves. Twenty-two calf-cow pairs were included in this survey. The median age at which calves became seronegative for BTV was 84 and 112 days as assayed by seroneutralisation test (SNT) and VP7 BTV competitive ELISA (cELISA), respectively. At the mean age of 118 days, 13/22 calves were immunized with inactivated BTV-8 vaccine. In most calves vaccination elicited a weak immune response, with seroconversion in only 3/13 calves. The amplitude of the humoral response to vaccination was inversely proportional to the maternal antibody level prior to vaccination. Thus, the lack of response was attributed to the persistence of virus-specific colostral antibodies that interfered with the induction of the immune response. These data suggest that the recommended age for vaccination of calves born to vaccinated dams needs to be adjusted in order to optimize vaccinal efficacy. 相似文献
116.
Charles R. Sweet Rebecca E. Watson Corinne A. Landis Joseph P. Smith 《Marine drugs》2015,13(8):4701-4720
Lipid A is a fundamental Gram-negative outer membrane component and the essential element of lipopolysaccharide (endotoxin), a potent immunostimulatory molecule. This work describes the metabolic adaptation of the lipid A acyl structure by Psychrobacter cryohalolentis at various temperatures in its facultative psychrophilic growth range, as characterized by MALDI-TOF MS and FAME GC-MS. It also presents the first elucidation of lipid A structure from the Colwellia genus, describing lipid A from strains of Colwellia hornerae and Colwellia piezophila, which were isolated as primary cultures from Arctic fast sea ice and identified by 16S rDNA sequencing. The Colwellia strains are obligate psychrophiles, with a growth range restricted to 15 °C or less. As such, these organisms have less need for fluidity adaptation in the acyl moiety of the outer membrane, and they do not display alterations in lipid A based on growth temperature. Both Psychrobacter and Colwellia make use of extensive single-methylene variation in the size of their lipid A molecules. Such single-carbon variations in acyl size were thought to be restricted to psychrotolerant (facultative) species, but its presence in these Colwellia species shows that odd-chain acyl units and a single-carbon variation in lipid A structure are present in obligate psychrophiles, as well. 相似文献
117.
Christophe Plomion Catherine Bastien Marie-Béatrice Bogeat-Triboulot Laurent Bouffier Annabelle Déjardin Sébastien Duplessis Bruno Fady Myriam Heuertz Anne-Laure Le Gac Grégoire Le Provost Valérie Legué Marie-Anne Lelu-Walter Jean-Charles Leplé Stéphane Maury Alexandre Morel Sylvie Oddou-Muratorio Gilles Pilate Léopoldo Sanchez Ivan Scotti Caroline Scotti-Saintagne Vincent Segura Jean-François Trontin Corinne Vacher 《Annals of Forest Science》2016,73(1):77-103
118.
Jean-Pierre?PérosEmail author Claire?Troulet Mika?l?Guerriero Corinne?Michel-Romiti Jean-Loup?Notteghem 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(4):407-416
Erysiphe necator, the causative agent of powdery mildew in grapevine, was introduced into Europe from North America during the middle of the
19th century. Our objective was to analyze the genetic variation and the population structure of the fungus in southern France.
The sample comprised 101 isolates and was mainly of flag shoot origin, i.e., infection of sprouting shoots after overwintering
of mycelium in buds. RAPD analysis identified different haplotypes that clustered in two genetic groups (A and B). The most
frequent haplotypes of each group were found in several different locations in two areas separated by 100 km and throughout
the 3 year period. Several haplotypes of both groups originated from flag shoots and were recovered over successive years
indicating that there is no correlation between genetic group and overwintering mode. All isolates of group A were of mating
type +, but those in group B could be either + or −. Lower genotypic diversity was detected within group A than within group
B. These results were consistent with the hypothesis that group A reproduces only asexually. 相似文献
119.
OBJECTIVE: To determine pharmacokinetic-pharmacodynamic (PK-PD) relationships and dose effects for meloxicam in horses and to propose a suitable dosage for use in clinical studies. ANIMALS: 6 adult horses. PROCEDURE: The study was conducted by use of a randomized, Latin-square design. Arthritis was induced in the right carpal joint of each horse by administration of Freund's complete adjuvant. Various dosages of meloxicam (0, 0.25, 0.5, 1.0, and 2.0 mg/kg, IV) were then administered. Validated endpoints including stride length and overall clinical lameness score (scale of 0 to 20) were used to assess the effect of meloxicam. The dose-effect relationship was quantified by use of a maximum possible effect (Emax) model. RESULTS: For stride length (expressed as a relative percentage increase from control values), the median effective dose (ED50) was 0.120 mg/kg for an Emax of 11.15%. For clinical lameness score (expressed as an absolute increase from the control value), the ED50 was 0.265 mg/kg for an Emax of 9.16 units. The PK-PD analysis allowed calculation of a median effective concentration of 130 ng/mL for stride length and 195 ng/mL for lameness score. Use of the Emax model predicted a maximal possible increase in effect of 19.5% for stride length and 13.91 units for lameness score. For stride length and lameness score, the Hill coefficient (slope) was extremely high, which suggested a steep dose-effect relationship. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study suggest that meloxicam is a potent anti-inflammatory drug in horses. A dosage of 0.6 mg/kg/d would be appropriate for use in a clinical study. 相似文献
120.
ABSTRACT Leaf rust uredospore production and lesion size were measured on flag leaves of adult wheat plants in a glasshouse for different lesion densities. We estimated the spore weight produced per square centimeter of infected leaf, per lesion, and per unit of sporulating area. Three levels of fertilization were applied to the plants to obtain different nitrogen content for the inoculated leaves. In a fourth treatment, we evaluated the effect of Septoria tritici blotch on leaf rust uredospore production. The nitrogen and carbon content of the spores was unaffected or marginally affected by lesion density, host leaf nitrogen content, or the presence of Mycosphaerella graminicola on the same leaf. In leaves with a low-nitrogen content, spore production per lesion was reduced, but lesion size was unaffected. A threshold effect of leaf nitrogen content in spore production was however, evident, since production was similar in the medium- and high-fertilizer treatments. In leaves inoculated with M. graminicola and Puccinia triticina, the rust lesions were smaller and produced fewer spores. The relationships among rust lesion density, lesion size, and uredospore production were fitted to a model. We determined that the density effect on spore production resulted mainly from a reduction in lesion size, the spore production per unit of sporulating surface being largely independent of lesion density. These results are consistent with those obtained previously on wheat seedlings. The main difference was that the sporulation period lasted longer in adult leaves. 相似文献