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241.
Myelopoiesis and marrow adherent cells in estradiol-treated mice 总被引:1,自引:0,他引:1
Myelopoiesis and marrow adherent cells were evaluated in C57Bl/6J mice at two and four weeks after treatment with 0.1 mg 17 beta-estradiol cyclopentylpropionate. Estradiol-treated mice were lymphopenic and eosinopenic at two and four weeks; in addition, neutropenia occurred at four weeks. Numbers of lymphoid, granulocytic, and erythroid cells were decreased in the marrow at two and four weeks. The numbers of granulocyte-macrophage and fibroblast colony-forming units in the humeral marrow were also decreased at two and four weeks. However, the hematopoietic ability of marrow adherent cells was unchanged in estradiol-treated mice. Thymic cortical atrophy, metaphyseal osteosclerosis, and neutrophilic infiltration of the uterus occurred in estradiol-treated mice. 相似文献
242.
Xenognosin production and tolerance to Striga asiatica infection of high-yielding maize cultivars 总被引:1,自引:0,他引:1
Summary Ten cultivars of maize, a number of which are high yielding in the presence of the weed Striga asiatica in sub-Saharan Africa, were tested for resistance and tolerance to this root hemiparasite. Observed in rhizotrons, Striga asiatica attached and developed on roots of all cultivars, indicating that none exhibited a true resistance mechanism. However, root exudates from two cultivars, IWD STR Co and Zea diploperennis BC4C2, stimulated relatively little germination of S. asiatica , indicating low xenognosin production, with few parasites attaching and no significant decrease in host height or biomass apparent after 55 days of infection. Cultivar 98 Syn WEC also exhibited no significant differences in height and biomass on infection despite high xenognosin production and a lack of resistance to parasite attachment and development, indicating the operation of a tolerance mechanism. Cross-breeding of these low xenognosin-producing maize cultivars and Striga -tolerant lines could produce cultivars that perform exceptionally well on Striga -infested soils. This study highlights the need for cereal breeders to distinguish between the different mechanisms underpinning host performance in the presence of Striga . 相似文献
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Simon J. Pierce Adriana Méndez‐Jiménez Kym Collins Marcela Rosero‐Caicedo Ara monadjem 《水产资源保护:海洋与淡水生态系统》2010,20(7):782-788
- 1. The whale shark (Rhincodon typus) is a popular focal species within the global marine tourism industry. Although this has contributed to increased protection being granted to the species in several countries, tourism itself can be detrimental to the sharks in the absence of appropriate management. Potential impacts can be mitigated, at least in the short term, by adherence to well‐designed interaction guidelines.
- 2. A burgeoning marine tourism industry based on swimming with whale sharks has developed at Tofo Beach in Mozambique. However, no formal management is currently in place at this site.
- 3. The behaviour of whale sharks during interactions with boats and swimmers were recorded during 137 commercial snorkelling trips run from Tofo Beach over a 20 month period. Whale sharks were encountered on 87% of trips, which operated year‐round.
- 4. Boat proximity and shark size were significant predictors of avoidance behaviour. No avoidance responses were recorded at >20 m boat distance.
- 5. The mean in‐water interaction time between sharks and swimmers was 8 min 48 s overall. There was a significant decrease in interaction times during encounters where sharks expressed avoidance behaviours, and also in cases where sharks had expressed boat avoidance behaviour before swimmers entered the water.
- 6. It is suggested that mean encounter times can be extended through adherence to a basic Code of Conduct for operators and swimmers that enforces minimum distances between the sharks, boats and swimmers. Using encounter time as a measure of the ‘success’ of interactions holds promise, as longer encounters appear to be indicative of lower impacts on sharks while also providing higher customer satisfaction for swimmers. Copyright © 2010 John Wiley & Sons, Ltd.
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F. E. Dowell E. B. Maghirang R. O. Pierce G. L. Lookhart S. R. Bean F. Xie M. S. Caley J. D. Wilson B. W. Seabourn M. S. Ram S. H. Park O. K. Chung 《Cereal Chemistry》2008,85(1):82-91
This study measured the relationship between bread quality and 49 hard red spring (HRS) or 48 hard red winter (HRW) grain, flour, and dough quality characteristics. The estimated bread quality attributes included loaf volume, bake mix time, bake water absorption, and crumb grain score. The best‐fit models for loaf volume, bake mix time, and water absorption had R2 values of 0.78–0.93 with five to eight variables. Crumb grain score was not well estimated, and had R2 values ≈0.60. For loaf volume models, grain or flour protein content was the most important parameter included. Bake water absorption was best estimated when using mixograph water absorption, and flour or grain protein content. Bake water absorption models could generally be improved by including farinograph, mixograph, or alveograph measurements. Bake mix time was estimated best when using mixograph mix time, and models could be improved by including glutenin data. When the data set was divided into calibration and prediction sets, the loaf volume and bake mix time models still looked promising for screening samples. When including only variables that could be rapidly measured (protein content, test weight, single kernel moisture content, single kernel diameter, single kernel hardness, bulk moisture content, and dark hard and vitreous kernels), only loaf volume could be predicted with accuracies adequate for screening samples. 相似文献
248.
North Island brown kiwi have been monitored by a standard call count index at 23 stations in Northland, New Zealand annually since 1995. An attempt is made here to determine whether there are any trends in call counts that relate to predator control and advocacy in and around each listening station. Both predator and advocacy effort were rated on a 0-3 scale at each of 23 listening stations, and kiwi calling rates analysed on a generalised linear model. An analysis of variance (ANOVA) indicated a positive response of call counts to predator control. There was a weaker relationship with advocacy, but because predator control and advocacy are correlated, it was not possible to separate their effects. Ground moisture levels had a significant positive effect on calls, while wind and rain had negative effects. Overall, the analysis suggested that this kind of management is benefitting kiwi in Northland. 相似文献
249.
Lascelles BD Hansen BD Thomson A Pierce CC Boland E Smith ES 《Veterinary anaesthesia and analgesia》2008,35(2):173-183
OBJECTIVE: To assess the correlation between data generated by an accelerometer-based activity monitor and the distance moved in cats. STUDY DESIGN: Prospective experimental study. ANIMALS: Three, four-year-old, male, purpose-bred research cats, weighing between 5.1 and 5.9 kg. METHODS: Part I: Collar and harness mounted accelerometers were evaluated in three cats, comparing simultaneously collected accelerometer data with movement data from computer-analyzed video. Part II: Cats wore collar and harness mounted accelerometers, and data were recorded for 4 weeks to evaluate day-to-day and week-to-week variation in activity. RESULTS: Part I: 432 hours of simultaneous video and accelerometer data were collected. The correlation between accelerometer counts and distance moved was 0.82 overall. Agreement between collar and harness mounted accelerometers was excellent with only 6% of the differences in measurements lying outside the mean difference +/- 2 standard deviations. The adjusted R(2) for harness accelerometer output and 6% mobility was 0.75; for movement 0.84; and for mean velocity 0.83. Evaluation of video indicated eating, grooming and scratching created high accelerometer counts with little effect on movement. Part II: There was a significant effect of day on harness (p < 0.001) and collar (p < 0.002) counts, with counts being lowest at the weekend. There was a significant effect of week on harness-mounted accelerometer counts (p < 0.034), but not on collar-mounted accelerometer counts. Harness accelerometer counts were lowest in week 1. CONCLUSION: Output from an acceleration-based digitally integrated accelerometer correlated well with distance moved and mobility in freely moving cats provided the mobility threshold in the analysis software was > or = 6%. CLINICAL RELEVANCE: Acceleration-based activity monitors may allow for objective measurement of improved mobility following analgesic treatment for conditions such as osteoarthritis. 相似文献
250.
Pierce JR 《Science (New York, N.Y.)》1977,195(4283):1092-1095