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41.
Coupling of south american and african plate motion and plate deformation   总被引:2,自引:0,他引:2  
Although the African Plate's northeastward absolute motion slowed abruptly 30 million years ago, the South Atlantic's spreading velocity has remained roughly constant over the past 80 million years, thus requiring a simultaneous westward acceleration of the South American Plate. This plate velocity correlation occurs because the two plates are coupled to general mantle circulation. The deceleration of the African Plate, due to its collision with the Eurasian Plate, diverts mantle flow westward, increasing the net basal driving torque and westward velocity of the South American Plate. One result of South America's higher plate velocity is the increased cordilleran activity along its western edge, beginning at about 30 million years ago.  相似文献   
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The goal of this study was to compare a traditional slow‐freeze method (TF) with an open unidirectional slow freeze cooling system (UF) for whole ovary cryopreservation. Therefore, whole pig ovaries were randomly assigned to (A) fresh control, (B) traditional slow freeze (TF) or (C) unidirectional slow freeze (UF). Ovaries were perfused with 10% DMSO in Krebs‐Ringer. For TF, whole ovaries were placed in specimen jars containing 10% DMSO and placed into a specialized container for freezing filled with propan‐2‐ol. For UF, whole ovaries were placed within a specially designed container containing 10% DMSO and transferred to a specialized freezing machine (CTE 920). Histological evaluation demonstrated intact morphology of follicles in all groups; however, an overall decrease of follicle numbers in TF (46%) and UF (50%) compared to fresh control. Live/dead assay indicated significantly lower populations of live cells in both TF (60%) and UF (58%) compared to fresh tissue (74%). TUNEL assay confirmed a difference in percentage of apoptotic follicles between fresh and TF, but there was no significant difference between fresh and UF. To improve the structural and functional integrity of whole ovaries, further investigation, especially into directional freezing, is needed. Whole ovary cryopreservation could provide opportunities for women facing fertility loss due to chemo‐ or radiotherapy treatment.  相似文献   
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The first report of the biological production of bromo ochratoxin B by Aspergillus ochraceus Wilh. is presented as well as a study of the influence of potassium bromide, potassium iodide, potassium fluoride, and potassium chloride on the production of ochratoxin A and ochratoxin B. Potassium fluoride and potassium iodide inhibited the growth of the fungus, whereas potassium chloride substantially stimulated the production of ochratoxin A in shaken solid substrate fermentation on whole wheat or shredded wheat, generally giving a high yield of ochratoxins. Increasing levels of potassium bromide led to a decline in ochratoxin A production and an increase in bromo-ochratoxin B, ochratoxin B, and 4-hydroxy ochratoxin B. Nevertheless, A. ochraceus was much less versatile in the bromo analogues than other fungi, which produce metabolites containing chlorine. Analysis included aminopropyl solid-phase extraction column cleanup followed by quantitative analysis on reversed-phase HPLC using fluorescence detection and employing N-(5-chloro-2-hydroxybenzoyl)phenylalanine as an internal standard.  相似文献   
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The addition of 0.5% (v/v) of Equex STM Paste (Nova Chemical Sales, Scituate Inc., MA, USA), whose active ingredient is sodium dodecyl sulphate (SDS), to a Tris–egg yolk extender was demonstrated to improve the longevity of frozen–thawed dog spermatozoa during in vitro incubation at 38°C. The aim of the first experiment was to compare the effects of two SDS‐containing compounds, Equex STM Paste and Equex Pasta (Minitüb, Tiefenbach, Germany), when added to a Tris–egg yolk based extender, on the post‐thaw longevity of dog spermatozoa, as well as on the intracellular Ca2+ concentration of spermatozoa, during post‐thaw incubation at 38°C. The post‐thaw sperm survival and longevity, as well as the quality of the sperm movement, were significantly better when using Equex STM Paste. Such prolonged sperm longevity, however, was associated to a higher intracellular Ca2+ concentration in a large subpopulation of the live spermatozoa. A second experiment was aimed to evaluate the effects of sperm dilution immediately post‐thaw with a Tris buffer containing glucose or fructose. The two Tris buffers were no different for any of the sperm parameters studied. The aim of a third experiment was to evaluate the sperm longevity, motility patterns and intracellular Ca2+ concentration of cryopreserved dog spermatozoa during post‐thaw incubation in capacitating conditions [canine capacitating medium (CCM) with or without 5 μg/ml of heparin]. Heparin had no significant effects on any of the sperm parameters evaluated. During the first 8 h of incubation, the majority of the live spermatozoa had a high intracellular Ca2+ content. However, after 8–10 h of incubation, it had significantly declined. The highest proportion of fast motile sperm, and the highest curvilinear velocity, average path velocity and amplitude of lateral head displacement for the total motile sperm were observed during the 2–4‐h incubation period. It was concluded that: (a) the addition of 0.5% (v/v) of Equex STM Paste to a Tris–egg yolk based extender significantly improved the post‐thaw longevity of dog spermatozoa, but the same concentration of Equex Pasta had no significant beneficial effects; (b) sperm dilution after thawing with a Tris buffer containing glucose or fructose made no difference in post‐thaw sperm longevity; (c) the addition of 5 μg/ml of heparin to CCM had no significant capacitating effects on frozen–thawed dog spermatozoa.  相似文献   
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SUMMARY Merino sheep, which were hand jetted with ivermectin jetting fluid, and untreated sheep were challenged with larval implants of Lucilia cuprina, Lucilia sericata, Calliphora noclva and Chrysomya ruflfacles at intervals of about 2 weeks from 6 to 16 weeks after treatment. Both Lucilia species produced strike rates of about 90% in untreated sheep; the respective rates were lower for Chr rufifacies (55%) and C nociva (60%). Strike rates for the treated group were about 17, 11, and 9% for L cuprina, L sericata, and Chr rufifacies, respectively. Only 1 implant site in the treated group was struck by C nociva. Treated sheep had significantly (P < 0.01) longer time to first strike than did untreated ones for each species of fly. L sericata, Chr rufifacies, and C nociva larvae implanted on treated animals had significantly (P < 0.05) longer time to first strike than did L cuprina larvae.  相似文献   
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This paper considers the replacement of some flooring materials that have well-documented sustainability issues with a material of lesser controversy. Many products used in the flooring industry contain a large amount of embodied energy and have issues with reuse, recycling and disposal. It has been argued that epoxidised linseed oil (ELO), made from renewable resources, could provide an attractive alternative to polyvinyl-chloride (PVC) flooring products in some applications. The objective of this study is to assess the effect of processing parameters on the final cure product of ELO and a di-acid cross-linker. The final cure product is assessed for the performance through a variety of methods standard to the flooring industry and compared to other flooring materials. This paper shows that for contract use, the product may have comparable performance to PVC products.  相似文献   
48.
SUMMARY A jetting fluid containing 7.5% w/v ivermectin, which was diluted to 0.03 mg/mL in water and applied using a standard hand jetting technique, was assessed for its efficacy in treating blowfly strikes on Merino sheep. Strikes were induced on sheep held under insectary conditions using laboratory-reared Lucilia cuprina. All struck sheep jetted at 28,48 or 72 hours after exposure to flies were successfully treated. All 1st, 2nd and early 3rd instar larvae were killed within 24 hours of treatment.  相似文献   
49.
Studies on preweaning piglet diarrhoea   总被引:1,自引:0,他引:1  
SUMMARY The aim of this study was to determine the cause and risk factors Involved in preweaning piglet diarrhoea. Faecal samples from 2380 diarrhoeic piglets, 5 to 30 days of age, were examined for enteropathogens. Isospora suls oocysts were detected in 53.8% of samples, Escherichia coll in 18.2% and rotavirus in 16.9%. I suis had the widest distribution, being present on 70.9% of 151 piggeries. The onset of diarrhoea occurred mainly between 7 and 14 days (77.5%), peaking at 10 days. Records of 4086 litters from two intensive piggeries were analysed and showed no seasonal variation or effect of sow parity on the incidence of piglet diarrhoea. I suis was the most common enteropathogen associated with diarrhoea in piglets from 5 days of age until weaning.  相似文献   
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