全文获取类型
收费全文 | 209篇 |
免费 | 9篇 |
专业分类
林业 | 2篇 |
农学 | 3篇 |
13篇 | |
综合类 | 16篇 |
农作物 | 1篇 |
水产渔业 | 8篇 |
畜牧兽医 | 172篇 |
园艺 | 1篇 |
植物保护 | 2篇 |
出版年
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 12篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 10篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 2篇 |
1969年 | 4篇 |
1968年 | 4篇 |
1945年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有218条查询结果,搜索用时 366 毫秒
51.
Cinefluorography and videoflurography were used to record and analyze the functional swallowing deficits of nine dogs with spontaneous oropharyngeal swallowing problems. Based on the clinical and radiographic signs observed in one dog with experimentally induced bilateral hypoglossal palsy and comparison with cinefluorograms of normal dogs, the nine spontaneous dysphagias were divided into five oral dysphagias and four pharyngeal dysphagias. Dogs with oral dysphagias had problems with tongue control and in prehending and transporting food and fluid to the oropharynx. On cinefluorograms, a poor closure of the oral egress led to the loss of contrast medium from the mouth, and a weak tongue-thrust action caused retention of contrast medium in the oropharynx. The clinical and radiographic signs could be duplicated by hypoglossal neurectomy. In contrast to the pharyngeal dysphagias, aspiration pneumonia was noticeably absent in oral dysphagias. The dogs with pharyngeal dysphagia had severe difficulties in transporting the food from the oropharynx to the laryngopharynx owing to a poor contractility of the pharyngeal muscles. The latter resulted in contrast medium retention in the pharynx and laryngotracheal aspiration. The need was stressed for a careful differentiation between oral and pharyngeal dysphagias on one hand, and cricopharyngeal dysphagias on the other hand. In oral dysphagias, cricopharyngeal myotomy appeared of no use. In pharyngeal dysphagias, cricopharyngeal myotomy severely aggravated the clinical signs by causing a cricopharyngeal chalasia. 相似文献
52.
53.
54.
J Veverka P Thomas A Harch B Clark JF Bell B Carcich J Joseph C Chapman W Merline M Robinson M Malin LA McFadden S Murchie SE Hawkins R Farquhar N Izenberg A Cheng 《Science (New York, N.Y.)》1997,278(5346):2109-2114
On 27 June 1997, the Near Earth Asteroid Rendezvous (NEAR) spacecraft flew within 1212 kilometers of asteroid 253 Mathilde. Mathilde is an irregular, heavily cratered body measuring 66 kilometers by 48 kilometers by 46 kilometers. The asteroid's surface is dark (estimated albedo between 0.035 and 0.050) and similar in color to some CM carbonaceous chondrites. No albedo or color variations were detected. The volume derived from the images and the mass from Doppler tracking of the spacecraft yield a mean density of 1.3 +/- 0.2 grams per cubic centimeter, about half that of CM chondrites, indicating a porous interior structure. 相似文献
55.
MC McCarthy MJ Travers A Kovacs W Chen SE Novick CA Gottlieb P Thaddeus 《Science (New York, N.Y.)》1997,275(5299):518-520
Two cumulene carbenes, H2C5 and H2C6, were detected in a supersonic molecular beam by Fourier transform microwave spectroscopy. Their rotational and leading centrifugal distortion constants were determined with high accuracy, such that the entire radio spectrum can now be calculated. Like the known carbenes H2C3 and H2C4, both molecules have singlet electronic ground states and linear carbon-chain backbones. They can be produced in sufficiently high concentrations in the laboratory that their electronic spectra, expected to lie in the visible, should be readily detectable by laser spectroscopy. The microwave spectra of other, more exotic isomers may be detectable as well. 相似文献
56.
57.
58.
SUMMARY Four dogs with disseminated aspergillosis caused by Aspergillus terreus were treated with oral itraconazole for 190 to 1095 days. Infection was eliminated in 1 dog. Two dogs were treated for 1000 and 1095 days but were eventually euthanased 572 and 485 days after treatment was stopped. At necropsy both dogs had widespread aspergillosis. The fourth dog was euthanased for other reasons after 190 days of treatment when it was showing a good clinical response although there was radiographic evidence that the disease was progressing. 相似文献
59.
60.
P.J. Pascoe J.E. Ilkiw W.D. Black J.M. Claxton C.M. Suter 《Veterinary anaesthesia and analgesia》1993,20(1):9-13
Alfentanil (50 μg/kg) was administered intravenously, over 1 minute, to 6 healthy cats. Blood samples were collected from a preplaced arterial catheter at 0.625, 1.25, 2.5, 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 360, and 480 minutes after the end of the alfentanil injection. A radio-immunoassay technique was used to measure alfentanil concentrations in plasma obtained from these samples. Arterial blood pressure was measured at 0.625, 1.25, 2.5, 5, 10, 15, 20, and 30 minutes and pH and blood gas measurements were carried out at 5, 10 and 30 minutes after the alfentanil. Analgesia, tested by placing a clamp on the base of the tail for 5 seconds, was assessed at each blood sampling time until analgesia was absent. The cats were observed for behavioural changes at each sample time. Alfentanil caused a transient increase in blood pressure and respiratory and metabolic acidosis. Following alfentanil all cats became excited and showed pupillary dilation. Analgesia was present for 21.7 ± 14 minutes. The plasma concentration-time data for 5 cats were best described by a 3 compartment open model with the curve fitting the equation: Cto= 162.6e-0.2062t+ 60.le-0.041t+ 13.2e-0.0062t The harmonic means for the half lives of the rapid distribution, the slow distribution and the elimination phases were 4.12, 18.8, 119.2 minutes respectively. 相似文献