全文获取类型
收费全文 | 350篇 |
免费 | 7篇 |
专业分类
林业 | 26篇 |
农学 | 4篇 |
11篇 | |
综合类 | 184篇 |
水产渔业 | 8篇 |
畜牧兽医 | 116篇 |
园艺 | 1篇 |
植物保护 | 7篇 |
出版年
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 17篇 |
2012年 | 15篇 |
2011年 | 23篇 |
2010年 | 12篇 |
2009年 | 13篇 |
2008年 | 12篇 |
2007年 | 18篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 13篇 |
2002年 | 18篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 15篇 |
1991年 | 20篇 |
1990年 | 23篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 3篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1942年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有357条查询结果,搜索用时 375 毫秒
351.
352.
Gibbons A 《Science (New York, N.Y.)》2011,332(6036):1370-1371
353.
354.
AA Smith LP Posner RE Goldstein JW Ludders HN Erb KW Simpson RD Gleed 《Veterinary anaesthesia and analgesia》2003,30(2):103-103
The pre‐medicant chosen may influence the ease with which gastroduodenoscopy (GD) is performed. The purpose of this study was to evaluate the relative ease of GD in cats under ketamine and isoflurane anesthesia after IM injection of hydromorphone (H, 0.1 mg kg?1), hydromorphone plus glycopyrrolate (HG, 0.1 mg kg?1 (H), 0.01 mg kg?1 (G)), medetomidine (M, 0.03 mg kg?1), or butorphanol (B, 0.4 mg kg?1). Eight cats were assigned randomly to receive each treatment in a cross‐over design with at least 7 days between treatments. Twenty minutes after pre‐medication, medetomidine produced greater (p = 0.001) sedation than the other treatments when assessed, using a subjective ordinal scale. The cats were injected with ketamine (10 mg kg?1 IM), orotracheally intubated, connected to a pediatric circle breathing system, and allowed to spontaneously breathe isoflurane in oxygen. Once end‐tidal isoflurane concentration was stable at 1.4% for 15 minutes, endoscopy was started. A single endoscopist (REG), who was unaware of the treatment used, performed all endoscopies. The endoscopist scored the difficulty of endoscopy subjectively (0–3). The significance of differences between treatments was evaluated using Friedman's test. Time for entering the stomach was 9.4 (4.7–15.9) (median (minimum–maximum)), 6.6 (5.2–11.7), 8.4 (6.3–16.5), and 7.7 (5.1–14.7) seconds and for entering the duodenum from the stomach was 20.5 (13.8–40.9), 18.2 (10.3–39.8), 20.2 (16.2–119.5), and 22.2 (11.8–83.8) seconds for H, HG, M, and B treatments, respectively. There were no significant differences in the time for, or difficulty of, endoscopy. We conclude that any of these drugs can be used satisfactorily at the doses and combinations tested to pre‐medicate cats prior to general anesthesia for GD. 相似文献
355.
C. J. Downes T. J. Gemmill S. E. Gibbons W. M. McKee 《The Journal of small animal practice》2009,50(10):525-535
Objectives : To evaluate the results of hemilaminectomy and vertebral stabilisation (+/? annulectomy) for the treatment of thoracolumbar disc protrusion. Methods : The medical records of dogs with thoracolumbar annular protrusions treated by hemilaminectomy and vertebral stabilisation were reviewed. Neurological function was assessed 24 hours following surgery. Long‐term follow‐up was by clinical examination or telephone questionnaire. Results : Twenty‐eight dogs fulfilled the criteria. Age ranged from 4 to 12·5 years (median 8 years, mean 7·7 years), bodyweight from 5·1 to 51·5 kg (median 28 kg, mean 27·1 kg), and duration of neurological signs before presentation from 48 hours to 104 weeks (median 5 weeks, mean 9·3 weeks). At presentation 22 dogs were ambulatory and six were non‐ambulatory. Myelography and/or magnetic resonance imaging (MRI) identified 31 thoracolumbar protrusions causing spinal cord compression. Unilateral hemilaminectomy was performed in 27 dogs and bilateral hemilaminectomy in one dog. Partial annulectomy was performed in 24 of 31 protrusions. Stabilisation was performed using vertebral body bone plates in 26 dogs and vertebral body screws and bone cement in two dogs. Internal vertebral venous plexus haemorrhage was recorded in nine dogs. A screw was inadvertently placed into an intervertebral disc in two dogs. Neurological examination 24 hours postoperatively revealed deterioration in pelvic limb motor function in 17 dogs. One dog was euthanatised at the owner’s request 6 days after surgery. Long‐term evaluation of 24 cases was performed 3 to 52 months following surgery (median 21 months, mean 23·9 months). Six dogs had improved from their preoperative status and one had deteriorated as assessed by the authors. Fifteen dogs had improved from their preoperative status and two were unchanged as assessed by owners. Clinical Significance : Hemilaminectomy and vertebral stabilisation are an effective treatment for chronic spinal cord compression due to thoracolumbar annular protrusion in dogs. A temporary deterioration in neurological function is not uncommon following surgery. Internal vertebral plexus haemorrhage and inappropriate vertebral body screw placement are potential complications. 相似文献
356.
In 1998, Countdown Downunder, Australia's national mastitis and cell count control programme, was created. With funding from the country's leading dairy organisation, Dairy Australia, this programme was originally intended to run for three years but is now in its tenth year. As it was the first time Australia had attempted a national approach to mastitis control on the farm, the first three years of the programme were largely concerned with the development of resources to be used by farmers and service providers. The second three years were devoted to training with both groups. Since that time, Countdown Downunder has entered into a second resource development phase. The goal of the programme was to achieve a reduction in the bulk milk somatic cell count from the Australian dairy herd. To achieve this, the programme had to develop resources with clear and consistent messages around mastitis and somatic cell count control on farms. It was determined that progress toward the goals would be made more rapidly if service providers were trained in the use of these resources prior to farmers. This paper reviews the Countdown Downunder programme from 1998 to 2007. 相似文献
357.
T.S. AAS B.F. TERJESEN T. SIGHOLT M. HILLESTAD J. HOLM S. REFSTIE G. BAEVERFJORD K.‐A. RØRVIK M. SØRENSEN M. OEHME T. ÅSGÅRD 《Aquaculture Nutrition》2011,17(6):657-670
Rainbow trout with initial body weight 1144 g were fed two diets with high (feed A) or low (feed B) water stability for 6 weeks. During the last 2 weeks either stable or fluctuating oxygen saturation, salinity and temperature was introduced. High water stability of the feed was associated with harder pellets, less dust formation and less broken pellets compared to feed with low water stability. During the first 4 weeks, feed intake was 23% higher in trout fed diet B than in those fed diet A. Fluctuating environment resulted in a severe drop in feed intake for both dietary groups. At termination of the trial, stomachs of trout fed feed B contained mashed pellets and free water and oil. Stomachs of trout fed feed A contained more intact pellets and little fluid. The apparent digestibility of protein, starch, dry matter and energy was highest in feed A. The apparent digestibility of P and Zn was highest at stable environment, and the absorption of P was highest from feed A. In conclusion, physical quality affected the nutritional value of the feeds, and differences in nutritional value at stable or fluctuating environment appeared to be related to feed intake. 相似文献