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211.
Two switchable, mesoscopically periodic materials were created by combining crystalline colloidal array (CCA) self-assembly with the temperature-induced volume phase transition of poly(N-isopropylacrylamide) (PNIPAM). Body-centered-cubic CCAs of hydrated, swollen PNIPAM particles Bragg-diffract infrared, visible, and ultraviolet light weakly, whereas arrays of compact shrunken particles diffract efficiently. A tunable diffracting array was also created by embedding a CCA of polystyrene spheres within a PNIPAM hydrogel that swells and contracts with temperature; thus the array lattice constant varies with temperature, and the diffracted wavelength was thermally tunable across the entire visible spectrum. These materials may find applications in many areas of optics and materials science. 相似文献
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213.
This case report describes the successful management of a stingray laceration and suspected envenomation using a combination of opioid analgesia, heat compression, antimicrobial therapy, surgical debridement and closure. Stingray envenomation in the dog is a rare clinical presentation and is yet to be documented in the Australian veterinary literature. Envenomation can be markedly painful and may cause swelling and local tissue necrosis. No consensus on treatment guidelines has been published. Diagnostics and treatments performed are outlined with recommendations on a management plan for future cases. 相似文献
214.
A Morillo Rodriguez C Balao da Silva B Macías‐García JM Gallardo Bolaños JA Tapia IM Aparicio C Ortega‐Ferrusola FJ Peña 《Reproduction in domestic animals》2012,47(6):995-1002
A total of 42 ejaculates were used in the experiment; six ejaculates per stallion, obtained from seven Pure Spanish stallions (PRE), were split and frozen in freezing media with different concentrations and combinations of cryoprotectant (CPA): (i) Cáceres (skim milk based extender) containing 2.5% glycerol (2.5GL), (ii) Cáceres containing 1.5% glycerol and 1.5% dimethylformamide (1.5%GL–1.5%DMFA), (iii) Cáceres extender supplemented with 1.5% glycerol and 2.5% dimethylformamide (1.5%GL–2.5%DMFA) and (iv) Cáceres extender supplemented with 4% dimethylformamide (4%DMFA). After at least 4 weeks of storage in liquid nitrogen (LN), straws were thawed and semen analysed by computer‐assisted sperm analysis and flow cytometry (membrane lipid architecture (Merocyanine 540), integrity and sublethal damage (YoPro‐1) and mitochondrial membrane potential (JC‐1)). After thawing, better results were observed in samples frozen in 4%DMFA or in combinations of 1.5%GL–2.5%DMFA, in fact total motility increased by 16% in the 4%DMFA group compared to 2.5%GL (P < 0.05). Also, there was an increment in the percentage of progressive motile sperm in the 1.5%GL–2.5%DMFA group (9.8% 2.5GL vs 19% in the 1.5%GL–2.5%DMFA group p < 0.05); also, samples frozen in the 4%DMFA group had more intact (YoPro‐1 negative) sperm post‐thawing, 29.3% in 2.5%GL vs 36.7% in 4%DMFA group (p < 0.05). Membrane lipid architecture was not affected by any of the cryoprotectants tested, while samples frozen in 4%DFMA had a lower percentage of mitochondria with lower membrane potential. It is concluded that DMFA improves the outcome of cryopreservation of stallion spermatozoa mainly reducing sublethal cryodamage. 相似文献
215.
Use of Density Centrifugation for Delayed Cryopreservation of Stallion Sperm: Perform Sperm Selection Directly after Collection or after Storage? 下载免费PDF全文
A Heutelbeck H Oldenhof K Rohn G Martinsson JM Morrell H Sieme 《Reproduction in domestic animals》2015,50(1):76-83
Equipment for cryopreservation of stallion sperm is not always available. In such cases, diluted semen can be shipped to a facility for later cryopreservation. The aim of this study was to evaluate if selection of sperm via density centrifugation yields higher survival rates when cryopreservation is to be delayed (i.e. carried out after 1 day of storage at 5°C). Two‐layer iodixanol as well as single‐layer Androcoll density centrifugation were tested and compared with samples prepared with standard centrifugation. Special emphasis was placed on comparing centrifugation on the day of semen collection with centrifugation after 1‐day refrigerated storage. Sperm morphology and motility as well as membrane and chromatin integrity were evaluated before and after centrifugation. Sperm motility and membrane integrity were also assessed after cryopreservation. It was found that both two‐ and single‐layer density centrifugation processing resulted in higher percentages of morphologically normal and motile sperm with higher membrane and chromatin integrity, as compared to standard centrifugation or diluted samples. Differences were only in the order of magnitude of 5%. Recovery rates after density centrifugation were only approximately 30–40%. When cryopreservation was carried out after 1‐day refrigerated storage, centrifugation processing of sperm directly after semen collection resulted in higher percentages of plasma membrane intact sperm post‐thaw as compared to performing centrifugation processing of stored sperm just prior to cryopreservation. No significant differences in progressively motile sperm post‐thaw were seen. Taken together, for delayed cryopreservation, it is best to perform density centrifugation directly after collection rather than immediately prior to cryopreservation. 相似文献
216.