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排序方式: 共有618条查询结果,搜索用时 31 毫秒
611.
Under environmental conditions favorable for wound healing, potato tubers became significantly (P = 0.05) more resistant toA. solani infection during a two-day interval between wounding and inoculation. This period coincided with the time required for wounded tubers to completely seal wounded surfaces by suberization at 15.6°C/98% RH. Suberization of the wounded surfaces provided tubers significant (P = 0.05) protection againstA. solani invasion but wound periderm development was also essential for total exclusion of the pathogen. Wound healing takes place faster at high temperatures and relative humidities. The effect of temperature is more critical in the wound healing process. 相似文献
612.
Talia Silva de Jaczko J. W. Brewer M. D. Harrison 《American Journal of Potato Research》1983,60(11):853-860
The potato blackleg bacteriumErwinia carotovora subsp.carotovora (Jones) Bergey et al. was found in feces and regurgitated material obtained from surface sterilized adult fruit flies,Drosophila melanogaster (Meigen), that had fed for five hours on nutrient agar cultures of the bacterium. The highest levels of bacteria were obtained from fecal material and it is likely that this is the source of most of the inoculum carried by these vectors. The bacteria were found to be present in the foregut, midgut, and hindgut ofD. melanogaster. The largest number of bacteria were in the foregut with the population level decreasing as distance down the digestive tract increased. It is probable that the association between the vector and the bacterium is accidental. The probability that the insect aids survival of the bacterium by protecting it from adverse environmental conditions is suggested. 相似文献
613.
Lies Durnez Harrison Sadiki Abdul Katakweba Robert R. Machang’u Rudovik R. Kazwala Herwig Leirs Françoise Portaels 《Tropical animal health and production》2009,41(8):1653-1659
A study was conducted to determine the prevalence of Mycobacterium bovis-infection and atypical mycobacterioses in different cattle herd management systems in and around Morogoro, Tanzania. Between
April and June 2005, a total of 728 bovines from 49 herds were tested for M. bovis-infection and atypical mycobacterioses. Milk samples were taken from tuberculin positive animals and analysed for the presence
of mycobacteria. Total prevalences of 2.5% and 10.1% were found for M. bovis-infection and atypical mycobacterioses respectively, with more M. bovis-infection in cattle in the extensive management system and more atypical mycobacterioses in cattle in the intensive management
system. From 8 out of 42 milk samples (19%) atypical mycobacteria were cultured. A higher prevalence of M. bovis-infection in the extensive sector could be due to several factors. In addition, such high prevalence puts herd owners and
their families at risk for BTB. Therefore control of BTB, as well as education of cattle owners is important, especially in
the extensive sector. 相似文献
614.
Henry Charles Van Ham Mike Grey Mark Cowley Neil Harrison Robert 《Water, air, and soil pollution》2000,117(1-4):123-131
A new technique was developed for field determination of N mineralization from biosolids, which provides a simple, inexpensive test that yields accurate results. A residuals technique was used; mineralization was defined as the difference between the original and final mass of organic nitrogen. Biosolids were collected from a number of British Columbia wastewater treatment plants (WWTPs), placed in porous ceramic tubes and incubated under controlled conditions. Variables studied included wet versus dry biosolids, application rate, tube size, inoculation solution, and the effect of a soil addition mixed with biosolids. There was little difference in N mineralization between wet and dried biosolids, however variability was reduced using dried biosolids. No difference was observed using different amounts of biosolids. When dried biosolids were inoculated with supernatant obtained from a soil and biosolids mixture, decomposition was higher than with supernatant from the individual mediums alone. However, mineralization was fairly close with all inoculates. The addition of soil had little effect on biosolids decomposition other than resulting in a higher variability. 相似文献
615.
Richard E. Harrison James J. Luby Glenn R. Furnier James F. Hancock 《Genetic Resources and Crop Evolution》2000,47(6):647-657
Variation for 24 morphological traits measured in a greenhouse environment and 36 randomly amplified polymorphic DNA (RAPD) markers was assessed among 318 wild octoploid strawberry (Fragariaspp.) genotypes from diverse habitats across the northern USA. RAPD marker frequencies and certain leaf and flower morphology traits (petiole color, leaf mass/area ratio, leaflet length and width, flower and receptacle diameter, petal width, flowers/inflorescence) were significantly different between the F. chiloensis-platypetala and F. virginiana-glauca species complexes. The proportion of variation accounted for by provenance effects was lower for the RAPD markers than for most morphological traits, especially in the F. virginiana-glauca species complex. Morphological traits of potential adaptive importance group the collection into provenances within each species-complex, and reflect the significant habitat and geographic differences across the region from which the germplasm was collected. Variation among populations within provenances was low for the molecular and most morphological traits, with a much larger amount of variability among plants within populations. Most of the variation for the presumably more selectively-neutral RAPD data was among plants within populations and populations within provenances rather than among the provenances that were recognized based on morphological traits, especially in the F. virginiana-glauca complex. Patterns of diversity for morphological traits must be considered, along with more selectively-neutral molecular characters such as RAPDs, to formulate effective sampling strategies and to properly estimate the quantity and apportionment of diversity within this germplasm. 相似文献
616.
G. B. L. Harrison T. R. Shakes C. M. Robinson S. B. Lawrence D. D. Heath R. P. Dempster M. W. Lightowlers M. D. Rickard 《Veterinary immunology and immunopathology》1999,70(3-4)
The efficacy and safety of a recombinant Taenia ovis protein was tested in sheep using 13 different adjuvant formulations, including oil adjuvants, aluminium salts, saponin, Iscoms and DEAE-dextran. The oil adjuvants, saponin and DEAE-dextran gave the highest antibody responses and greatest degree of protection against challenge infection with T. ovis eggs. Duration of immunity studies with a saponin based vaccine showed that highly significant protection (>90% reduction of cyst numbers) was achieved when sheep were challenge infected one month after immunisation. Significant protection (79%) was still present when sheep were challenged 6 months after immunisation. The optimum dose for this batch of saponin was 10 mg, which stimulated a peak antibody titre of 38,400, 4 weeks after immunisation and did not cause injection site reactions. Dialysed saponin was shown to retain its adjuvant properties and allowed an increase in dose to 30 mg without site reaction, resulting in a peak antibody titre of 51,200. 相似文献
617.
S M Newell G W Ellison J P Graham P E Ginn O I Lanz J M Harrison J S Smith J M Van Gilder 《American journal of veterinary research》1999,60(6):775-779
OBJECTIVE: To determine scintigraphic, sonographic, and histologic changes associated with renal autotransplantation in cats. ANIMALS: 7 adult specific-pathogen-free cats: 5 males, 2 females, 1 to 9 years old. PROCEDURE: Renal autotransplantation was performed by moving a kidney (5 left, 2 right) to the left iliac fossa. Before and at multiple times after surgery, for a total of 28 days, cats were evaluated by B-mode and Doppler ultrasonography, scintigraphy, and renal biopsy. RESULTS: By 24 hours after surgery, a significant decrease (42%) in mean glomerular filtration rate (GFR) and an increase in mean renal size (81% increase in cross-sectional area) were evident in the transplanted kidney, compared with preoperative values. By postsurgery day 28, reduction in GFR was 23%. Significant changes in renal blood flow velocity were identified in both kidneys. Consistent changes in resistive index or pulsatility index for either kidney could not be identified. When all postoperative histologic data were combined, the histologic score, indicating degree and numbers of abnormalities detected, for the transplanted kidney was significantly higher than that for the control kidney. CONCLUSIONS: Significant changes in renal function, size, and histologic abnormalities develop secondary to acute tubular necrosis in cats after uncomplicated renal autotransplantation. CLINICAL RELEVANCE: Evaluation of renal size and function may be of benefit for clinical evaluation of feline renal transplant patients, whereas measurement of the resistive index may be of little clinical value. 相似文献
618.