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1.
Bowman DD Legg W Stansfield DG 《Veterinary therapeutics : research in applied veterinary medicine》2002,3(3):286-289
Efficacy of moxidectin injection (ProHeart 6 Sustained Release Injectable for Dogs, Fort Dodge Animal Health) against naturally acquired infections of Trichuris vulpis was compared with that of milbemycin oxime/lufenuron tablets (Sentinel Flavor Tabs, Novartis Animal Health). Eighteen dogs infected with T. vulpis were ranked by egg counts and randomly allocated to treatment with moxidectin (170 micro g/kg), milbemycin (500 micro g/kg)/lufenuron (10 mg/kg), or to an untreated control group (six dogs per treatment). Dogs were euthanized for worm counting 7 days after treatment. Efficacy of milbemycin/lufenuron against T. vulpis was 99.6 %, compared with 67.5 % for moxidectin. The commercial formulation of milbemycin oxime/lufenuron provided excellent control of whipworm infection, whereas moxidectin demonstrated variable efficacy against this parasite. 相似文献
2.
Use of variations in natural nitrogen isotope abundance for environmental studies: a questionable approach 总被引:2,自引:0,他引:2
3.
Long base line interferometry: a new technique 总被引:1,自引:0,他引:1
Broten NW Legg TH Locke JL McLeish CW Richards RS Chisholm RM Gush HP Yen JL Galt JA 《Science (New York, N.Y.)》1967,156(3782):1592-1593
The technique of using magnetic-tape recorders and atomic frequency standards to operate two widely separated radio telescopes as a phase-coherent interferometer when the stations have no radio-frequency connecting link has been successfully tested at the National Research Council of Canada's Algonquin Radio Observatory. 相似文献
4.
A coppicing technique was used to assess the incidence of latent and missed infection around 76 outbreaks of cocoa swollen shoot disease found during routine surveys of cocoa farms in Ghana. When all apparently healthy trees were coppiced within at least 27 m of trees found with symptoms, some failed to regenerate, with overall mortalities of 15% and 19% in progenies of Upper Amazon and West African Amelonado parentage, respectively. Many of the regenerating shoots developed stem and/or leaf symptoms of swollen shoot disease within 3 years of coppicing. There were great differences between sites, with overall incidences of infection of 21% and 16% in the Amazon and Amelonado plantings, respectively. The infections revealed by coppicing were not usually grouped closely around trees originally found with symptoms. Gradients of infection were seldom evident and the overall incidence of infection within 3 m of the initial outbreak areas (17%) was little greater than that beyond (14%). The original inspections of the standing trees detected only c. 12% and 18% of all the infected trees present at the Amazon and Amelonado sites, respectively. These results emphasize the limitations of routine inspections in determining the true incidence of infection. They have an important bearing on the conduct and effectiveness of the eradication measures adopted in Ghana and are discussed in relation to the future policy for limiting spread. 相似文献
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7.
Survey on whiteflies and their parasitoids in cassava mosaic pandemic areas of Tanzania using morphological and molecular techniques 下载免费PDF全文
8.
Cindy L. Yu Jason C. Legg 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(2):139-157
The National Resources Inventory (NRI) is a large-scale longitudinal survey conducted to assess trends and conditions of nonfederal
land. A key NRI estimate is year-to-year change in acres of developed land, where developed land includes roads and urban
areas. In 2003, a digital data collection procedure was implemented replacing a map overlay. Data from an NRI calibration
experiment are used to estimate the relationship between data collected under the old and new protocols. A measurement error
model is postulated for the relationship, where duplicate measurements are used to estimate the error variance of the new
procedure. If any significant discrepancy is detected between new and old measures, some parameters that govern the algorithm
for the new protocol can be changed to alter the relationship. Parameters were initially calibrated so overall averages nearly
match for the new and old protocols. Analyses on the data after initial parameter calibration suggest that a line with an
intercept of 0 and a slope of 1 is an acceptable representation for the relationship between the two determinations. Estimation
of the measurement error variances as functions of the proportion of developed land are also given. 相似文献
9.
D. E. Legg S. M. van Vleet D. W. Ragsdale R. W. Hansen B. M. Chen L. Skinner 《国际虫害防治杂志》2013,59(2):147-154
Sampling theory was combined with resampling techniques to determine the number of location-years needed for estimating an insect's required thermal summation and lower developmental threshold from field-based studies. This was done by analysing 19 location-years of field observations on the first emergence of Apthona nigriscutis Foudras, an important biological control agent of the noxious weed, leafy spurge (Euphorbia esula L.). Results indicated that 5 - 7 location-years were needed to estimate that insect's mean required thermal summation and mean lower developmental threshold for predicting first adult emergence. However, if the wish was to estimate the median required thermal summation and median lower developmental threshold for that purpose, then 8 - 11 location-years were needed to obtain acceptable estimates of those parameters. The implications of these and other findings are discussed. 相似文献
10.
The successful development of phenology models from field studies depends on many factors, some of which are entirely under the control of pest managers. For example, one such factor is the choice of method for calculating thermal units. In this study, we have demonstrated that four methods for calculating thermal units provided for acceptable predictions of one phenological event of one insect species, while another method for calculating thermal units did not. The measure of central tendency (mean or median) that is used to estimate lower developmental temperatures and required thermal summations is another factor that pest managers can control when developing phenology models from field studies. Here, we show that predictions that were made when using phenology models based on median lower developmental temperatures and median required thermal summations were superior to predictions that were made when using phenology models based on mean lower developmental temperatures and mean required thermal summations. The use of bootstrap vs. non-bootstrap estimates of lower developmental temperatures and required thermal summations is yet another factor that pest managers can control when developing phenology models from field studies. In this study, we found that calculating and using bootstrap estimates of lower developmental temperatures and required thermal summations in phenology models did not improve the predictions of one phenological event for one insect species. The implications of these and other findings are discussed. 相似文献