全文获取类型
收费全文 | 410篇 |
免费 | 18篇 |
专业分类
林业 | 16篇 |
农学 | 9篇 |
基础科学 | 3篇 |
75篇 | |
综合类 | 70篇 |
农作物 | 9篇 |
水产渔业 | 25篇 |
畜牧兽医 | 148篇 |
园艺 | 4篇 |
植物保护 | 69篇 |
出版年
2023年 | 5篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 12篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 13篇 |
2012年 | 18篇 |
2011年 | 30篇 |
2010年 | 16篇 |
2009年 | 13篇 |
2008年 | 31篇 |
2007年 | 27篇 |
2006年 | 21篇 |
2005年 | 24篇 |
2004年 | 22篇 |
2003年 | 22篇 |
2002年 | 17篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1994年 | 2篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1976年 | 2篇 |
1971年 | 3篇 |
1967年 | 2篇 |
1942年 | 2篇 |
1936年 | 1篇 |
1932年 | 1篇 |
1927年 | 1篇 |
1918年 | 1篇 |
1917年 | 1篇 |
1916年 | 1篇 |
1870年 | 1篇 |
排序方式: 共有428条查询结果,搜索用时 234 毫秒
101.
Sharlee A. Haas DVM Elizabeth Davidow DVM DACVECC 《Journal of Veterinary Emergency and Critical Care》2008,18(6):646-653
Objective– To describe successful management of saltwater near-drowning in a dog using mechanical ventilation. Case Summary– A 7-year-old spayed female Golden Retriever weighing 37 kg was referred for mechanical ventilation after saltwater submersion injury. The dog had a history of rare seizures characterized by pre-ictal agitation. On the morning of the event, the dog became agitated and ran toward Puget Sound. The owners discovered the dog unconscious in approximately 25.4 cm (10 in) of water, with her head submerged. The owners estimated that the dog was submerged for approximately 30 seconds. The dog was presented immediately to the nearest emergency facility where initial diagnostic testing and treatment included venous blood gases, nasal oxygen, and IV fluids. The dog was dyspneic despite nasal oxygen administration and was referred for mechanical ventilation. Upon arrival the patient was cyanotic with an arterial partial pressure of oxygen of 38 mm Hg (reference interval 85–100 mm Hg) and oxygenation saturation of 62% (reference interval >95%). Thoracic radiographs were taken and revealed severe, bilateral pulmonary infiltrates. The patient was ventilated for 70 hours and was discharged 4 days later. Complications included pneumonia and phlebitis at the site of a cephalic IV catheter. Follow up thoracic radiographs 10 days after discharge were within normal limits and the owners report a full recovery at 1 year. New or Unique Information Provided– Submersion injury can result in acute respiratory distress syndrome in dogs. Mechanical ventilation provided critical support during pulmonary recovery in this dog. 相似文献
102.
1. The apparent and true metabolisable energy values of carob pods meal for geese were measured to be 6.1 MJ/kg and 6.6 MJ/kg respectively. 2. Performance from 5 to 12 weeks was examined in geese fed on four diets containing 0, 100, 200 and 300 g/kg of carob pods meal. 3. The inclusion of carob pods meal up to 200 g/kg in geese diets did not affect the performance. 4. At 300 g/kg performance was highly depressed. 5. The digestibility of protein in the diets decreased linearly with an increase in the level of inclusion of carob pods meal. 6. The length of small intestine, large intestine and caeca and the weight of gizzard expressed per kg of body weight increased with an increase in the level of carob pods meal, which is rich in fibre, in the diets. 相似文献
103.
P Wohlsein G Trautwein B Stolze L Haas O R Kaaden 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1990,37(9):651-659
On tissues from naturally infected non-Aleutian mink an immunohistological study was performed using monoclonal antibodies and the immunoperoxidase method. Structural proteins of ADV were demonstrated in cryosections and in ethanol-fixed and paraffin-embedded material which provide antigen detection in a similar amount together with good histological structure. In lymphoid organs viral antigen was restricted to B-cell areas, particularly lymphoid follicles. The pattern of antigen distribution was typical for follicular dendritic cells which are capable to retain immune complexes. Beside macrophages in the interior of lymphoid follicles most likely proliferating B-lymphoblasts reveal nuclear and cytoplasmatic presence of structural proteins indicating viral replication. Cells of the mononuclear phagocyte system such as cells of lymphatic sinuses and hepatic Kupffer cells harbor viral protein in the cytoplasm, probably resulting from phagocytosis of immune complexes. Renal glomeruli were consistently negative for virus antigen whereas in interstitial infiltrates cells resembling macrophages stained positive for ADV structural proteins. 相似文献
104.
Y. De Haas L. L. G. Janss & H. N. Kadarmideen 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2007,124(5):277-285
Genetic correlations between body condition score (BCS) and fertility traits in dairy cattle were estimated using bivariate random regression models. BCS was recorded by the Swiss Holstein Association on 22,075 lactating heifers (primiparous cows) from 856 sires. Fertility data during first lactation were extracted for 40,736 cows. The fertility traits were days to first service (DFS), days between first and last insemination (DFLI), calving interval (CI), number of services per conception (NSPC) and conception rate to first insemination (CRFI). A bivariate model was used to estimate genetic correlations between BCS as a longitudinal trait by random regression components, and daughter's fertility at the sire level as a single lactation measurement. Heritability of BCS was 0.17, and heritabilities for fertility traits were low (0.01-0.08). Genetic correlations between BCS and fertility over the lactation varied from: -0.45 to -0.14 for DFS; -0.75 to 0.03 for DFLI; from -0.59 to -0.02 for CI; from -0.47 to 0.33 for NSPC and from 0.08 to 0.82 for CRFI. These results show (genetic) interactions between fat reserves and reproduction along the lactation trajectory of modern dairy cows, which can be useful in genetic selection as well as in management. Maximum genetic gain in fertility from indirect selection on BCS should be based on measurements taken in mid lactation when the genetic variance for BCS is largest, and the genetic correlations between BCS and fertility is strongest. 相似文献
105.
106.
Highest inorganic bromine residues (30 ppm) were found when soil was fumigated with liquid methyl bromide (MB) introduced
by conventional means into evaporating dishes. With preheated (vaporized) MB or injection of MB/chloropicrin (CP) mixtures,
bromide concentrations were reduced by 50%. They were uniform throughout the soil (0 to 60 cm) except after MB/CP injection,
when larger residues were found in the 30-60 cm layer. Leaching with 2000 mp3/ha (20 cm) of water always reduced bromide content to 7.5 and 10 ppm at the 0-30 and 30-60 cm depth, respectively. Organic
amendments to soils substantially increased bromide levels up to 118 ppm, most of which was found in the upper soil layers;
two teachings with 2000 mp3 /ha water were required to return the soils to their normal state.Sclerotium rolfsii andFusarium oxysporum f. sp.dianthi cultures buried in soil were eliminated from the upper 30 cm with MB applied either conventionally or preheated. At 50 cm,
500 kg/ha of the preheated gas was superior to 1000 kg/ha of the cold gas. All MB fumigations suppressed carnation flower
yields compared with CP alone but were superior to no treatment. After leaching, MB-fumigated soils yielded the highest number
of flowers. 相似文献
107.
108.
Herold FC De Haas K Cooper D Colenbrander B Nöthling JO Theunisen W Spillings B Gerber D 《The Onderstepoort journal of veterinary research》2004,71(3):203-210
Assisted reproductive techniques might prove themselves useful tools in producing buffaloes free of specific diseases (BFSD), which are in demand in South Africa. Freezing protocols for African buffalo semen must not only result in good post-thaw qualities, but must also be practical. Epididymal sperm from six mature African buffalo bulls was collected, diluted with three different semen extenders and frozen. Pre-freezing equilibration times between 2 and 9 h were tested. Total and progressive motility, longevity and acrosomal integrity were measured and compared. The use of Triladyl proved to result in better post-thaw parameters than the other two diluents. Equilibration times of between 4 and 9 h did not influence post-thaw sperm qualities significantly. For some of the treatments, exposure to semen extenders before freezing for less than 4 h resulted in inferior post-thaw semen parameters. 相似文献
109.
110.