全文获取类型
收费全文 | 483篇 |
免费 | 46篇 |
专业分类
林业 | 8篇 |
农学 | 8篇 |
基础科学 | 2篇 |
99篇 | |
综合类 | 66篇 |
农作物 | 29篇 |
水产渔业 | 17篇 |
畜牧兽医 | 282篇 |
园艺 | 5篇 |
植物保护 | 13篇 |
出版年
2020年 | 7篇 |
2019年 | 6篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 49篇 |
2012年 | 19篇 |
2011年 | 20篇 |
2010年 | 14篇 |
2009年 | 14篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 13篇 |
2003年 | 23篇 |
2002年 | 9篇 |
2001年 | 18篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1997年 | 7篇 |
1994年 | 6篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1977年 | 5篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 6篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1961年 | 3篇 |
1958年 | 3篇 |
1936年 | 3篇 |
1897年 | 3篇 |
1896年 | 3篇 |
排序方式: 共有529条查询结果,搜索用时 406 毫秒
41.
A case of stilboestrol toxicity is described in a dog which was treated for prostatic hyperplasia with stilboestrol dipropionate (10 mg) daily for 5 days. An initial anaemia and thrombocytopaenia of 19,500/microliters was recorded on day 11, and a severe leukocytosis of 125,300/microliters on day 15 was followed by a precipitous drop to 8,400/microliters on day 21. The dog received antibiotic treatment for concurrent peritonitis and prostatitis/cystitis between days 7 and 15. The dog died on day 41 with marrow aplasia. 相似文献
42.
43.
44.
45.
Students in veterinary schools can experience stress in balancing the different demands on them-academic, interpersonal, intrapersonal, and professional or work related-as well as managing potential conflict between animal and human interests. Practicing veterinarians report many similar stressors and reactions. Stressful stimuli produce stress reactions that can be inimical to physical and psychological well-being, and students' performance in veterinary programs can be adversely affected if they do not have coping resources. While there has been some research into stress among university students in general, and among medical students in particular, there is little on the experience of veterinary students. This article describes a study by the School of Psychology, commissioned by the Department of Veterinary Clinical Sciences, at Murdoch University in Western Australia. It was designed to investigate the levels and causes of stress among, and the frequency and type of coping strategies used by, fourth- and fifth-year students. Results indicate that the students in this cohort faced frequent stressors and felt at least moderately stressed but did not routinely and systematically use a range of coping strategies. Academic stressors and perceived responsibilities attached to moving into practical or professional areas figured strongly and were associated with higher levels of stress in the students, in particular physical sequelae. Though the numbers were small, it is of concern that some students were using measures that were potentially harmful. Some recommendations are made here about measures that veterinary programs may be able to incorporate to address stress in their students. Information is included on current strategies within the curriculum to manage potential stressful situations as part of students' professional development. 相似文献
46.
47.
Two experiments were conducted to determine the effect of feed withholding on carcass and viscera weights and meat quality in grow-finish swine. Experiment 1 included 528 pigs that were marketed from 24 pens and subjected to either 6 (control) or 24 h of feed withholding before marketing. Experiment 2 included 324 pigs that were marketed from 36 pens that were subjected to 6 (control), 16, or 24 h of feed withholding before marketing. In both experiments, pigs from each pen were marketed over a 14-d period in three groups, each 7 d apart. In Exp. 1, withholding feed for 24 h decreased viscera weight, carcass weight and yield, and feed intake during the 14-d marketing period compared with the control group (P < 0.05). Subjective measures of color, firmness, and marbling in fresh pork did not differ for the two treatment groups. In Exp. 2, withholding feed for 16 or 24 h decreased (P < 0.05) viscera weight compared with that of the control group. Withholding feed for 24 h decreased feed intake during the 14-d marketing period compared with intake of the control group. Withholding feed for 16 h did not decrease carcass weight, but carcass weights in the 24-h group were lower than those of the 16-h group in this Exp. 2 (P < 0.05). Color, firmness, marbling, and shear force did not differ among treatment groups in Exp. 2; however, cooking loss in pork from the control group exceeded that of the 24-h treatment. Gain:feed and ADG were not affected by treatment during the marketing period in either experiment. We conclude that withholding feed for either 16 or 24 h decreases viscera weight and feed intake during the marketing phase in finishing swine. These changes could potentially benefit both the producer and the processor with only minimal effects on carcass weight and pork quality. 相似文献
48.
AIM: To develop a technique to estimate the volume of epithelial lining fluid (ELF) obtained during bronchoalveolar lavage (BAL) and pleural lavage (PL) in the dog, using the urea dilution method. METHODS: BAL and PL fluids were obtained by saline lavage of pulmonary and pleural cavities of nine clinically healthy mixed-breed dogs immediately after euthanasia. Cell counts in the BAL and PL fluids were measured using standard techniques. The concentration of ELF in each lavage fluid was calculated from the relative concentration of urea in plasma and in each type of lavage fluid. Cell counts in ELF were then calculated. RESULTS: There were substantially higher cell counts in ELF compared to BAL or PF fluid. However, nucleated cell counts in ELF could not be predicted from cell counts in BAL or PL fluid. CONCLUSIONS AND CLINICAL RELEVANCE: These results suggest that accurate assessment of cellular or non-cellular components in lavage fluids should include a calculation of the proportion of ELF recovered, using a method such as urea dilution. 相似文献
49.
AIM: To investigate the presence of surface-active phospholipid (SAPL, or surfactant) in equine tendon and tendon sheath fluid. METHODS: The left front flexor tendon and sheath were removed from five Thoroughbred horses. Phospholipid was extracted from tendon sheath fluid using Folch reagent and quantified using spectroscopy. Transmission electron microscopy (TEM) was used to observe the tendon surfaces. RESULTS: The presence of phospholipid (90.6 (SD 4.3) microg/ml) in tendon sheath fluid, plus the appearance of oligolamellar layers and lamellar bodies on the tendon surface were indicative of SAPL. CONCLUSIONS: Evidence of SAPL was found in equine tendon, and may have a similar lubricating function as reported for synovial joints. CLINICAL RELEVANCE: These findings may have important implications for normal tendon function and possible therapeutic adjuncts for tendon and tendon sheath injuries. 相似文献
50.
Cattle on 18 of 21 farms in north-east Scotland were found to have low whole blood activities of the selenium-containing enzyme, glutathione peroxidase (less than 5 units per ml whole blood), and a low blood concentration of selenium (less than 0.05 mg per litre). These cattle had all been fed on locally produced feedstuffs without any mineral supplementation. The low selenium status in cattle occurred on farms with soils derived from a range of parent material, no one particular type predominating. 相似文献