全文获取类型
收费全文 | 233篇 |
免费 | 5篇 |
专业分类
林业 | 9篇 |
农学 | 2篇 |
11篇 | |
综合类 | 38篇 |
水产渔业 | 5篇 |
畜牧兽医 | 147篇 |
园艺 | 7篇 |
植物保护 | 19篇 |
出版年
2022年 | 3篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2016年 | 2篇 |
2014年 | 7篇 |
2013年 | 11篇 |
2012年 | 6篇 |
2011年 | 4篇 |
2010年 | 9篇 |
2009年 | 10篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 18篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1994年 | 3篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 7篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1967年 | 4篇 |
1942年 | 2篇 |
1922年 | 1篇 |
1917年 | 1篇 |
1906年 | 1篇 |
1904年 | 1篇 |
1901年 | 1篇 |
1898年 | 1篇 |
1896年 | 2篇 |
1885年 | 1篇 |
1883年 | 1篇 |
排序方式: 共有238条查询结果,搜索用时 62 毫秒
11.
Rusbridge C MacSweeny JE Davies JV Chandler K Fitzmaurice SN Dennis R Cappello R Wheeler SJ 《Journal of the American Animal Hospital Association》2000,36(1):34-41
Syringohydromyelia secondary to foramen magnum overcrowding is described in seven Cavalier King Charles spaniels. Clinical signs were consistent with a central spinal cord lesion. The most common signs were persistent scratching at the shoulder region with apparent neck, thoracic limb, or ear pain and thoracic limb lower motor neuron deficits. The diagnosis was made by magnetic resonance imaging. The syringohydromyelia is postulated to be a consequence of an occipital bone malformation resulting in a small caudal fossa and cerebellar herniation. Clinical signs improved but did not completely resolve when the dogs received treatment with corticosteroids or nonsteroidal anti-inflammatory drugs. 相似文献
12.
Chandler WH 《Science (New York, N.Y.)》1942,95(2475):563-567
13.
14.
A four-month-old male Labrador retriever was presented for polyuria, polydipsia and persistent euglycaemic glucosuria. On referral, diagnostic tests demonstrated abnormal fractional excretions of electrolytes, increased urinary excretion of selected amino acids, mild renal tubular acidosis and mild proteinuria, indicating renal tubular dysfunction. Pyelonephritis was suspected and potentiated amoxycillin was administered. On re-evaluation at six months of age, the dog was no longer polyuric or polydipsic and the metabolic abnormalities associated with the tubulopathy had resolved. Transient Fanconi's syndrome has not previously been reported in small animals. This report demonstrates the potential for recovery of function in cases presenting with renal tubulopathies. 相似文献
15.
In maize, timing of vegetative phase change has been implicated in the response to certain pests and environmental stresses. Common rust is the most serious disease of sweet corn in the north central United States. Sweet corn hybrids differing for resistance to common rust were evaluated for vegetative phase change traits. There were significant differences among hybrids for all vegetative phase change traits measured, as well as resistance to common rust. Certain hybrids displayed rapid transition (within two leaves) from juvenile to adult vegetation, while others displayed prolonged transition (within four leaves). There were no significant correlations between vegetative phase change traits and common rust severity among the commercial sweet corn hybrids evaluated in this experiment. 相似文献
16.
Evolution of bunyaviruses by genome reassortment in dually infected mosquitoes (Aedes triseriatus) 总被引:2,自引:0,他引:2
Aedes triseriatus mosquitoes became dually infected after ingesting two mutants of LaCrosse (LAC) virus simultaneously or after ingesting, by interrupted feeding, the two viruses sequentially within a 2-day period. After 2 weeks of incubation, approximately 25 percent of the vectors contained new virus genotypes as the result of RNA segment reassortment. New viruses were transmitted when the mosquitoes fed on mice. Viruses ingested more than 2 days after the initial infecting virus did not cause superinfection of the mosquito vectors. 相似文献
17.
Observations of the Galilean satellites with the radar system at the Arecibo Observatory, Puerto Rico, show that their surfaces are highly diffuse scatterers of radio waves of length 12.6 centimeters; spectra of the radar echoes are asymmetric and broad. The geometric radar albedos for the outer three satellites-0.42 +/- 0.10, 0.20 +/- 0.05, and 0.09 +/- 0.02 for Europa, Ganymede, and Callisto, respectively-show about the same relative decreases as do the optical albedos, although the latter presumably bear only on material much nearer the surface. Radii of 1420 +/- 30, 2640 +/- 80, and 2360 +/- 70 kilometers for Europa, Ganymede, and Callisto were determined from the radar data and are in good agreement with the corresponding optically derived values. Io, observed successfully only once, appears to have an albedo comparable to Ganymede's, but no radius was estimated for it. 相似文献
18.
Lorenz KT Chandler DW Barr JW Chen W Barnes GL Cline JI 《Science (New York, N.Y.)》2001,293(5537):2063-2066
The preferred sense of product molecule rotation (clockwise or counterclockwise) in a bimolecular collision system has been measured. Rotationally inelastic collisions of nitric oxide (NO) molecules with Ar atoms were studied by combining crossed molecular beams, circularly polarized resonant multiphoton ionization probing, and velocity-mapped ion imaging detection. The observed sense of NO product rotation varies with deflection angle and is a strong function of the NO final rotational state. The largest preferences for sense of rotation are observed at the highest kinematically allowed product rotational states; for lower rotational states, the variation with deflection angle becomes oscillatory. Quantum calculations on the most recently reported NO-Ar potential give good agreement with the observed oscillation patterns in the sense of rotation. 相似文献
19.
S Patton P T Chandler E B Kalan A R Loeblich G Fuller A A Benson 《Science (New York, N.Y.)》1967,158(802):789-790
Two harvests of ocean-growing red tide, comprised mainly of Gonyaulax polyedra, were evaluated in limited trials of rat feeding. The protein of red tide (25 to 30 percent, dry basis) supported growth satisfactorily. The essential amino acid composition of the protein closely resembles that of casein, the major protein of milk. As a marine resource, plankton represents a challenge for research. 相似文献
20.
A scanning spectrometer with lithium fluoride, ammonium dihydrogen phosphate, and gypsum crystals was used to detect the x-ray spectrum of a normal centriole, the transmitted electron image of which was used to focus the exciting electron beam to the size, shape, and position of the centriole in a 700-angstrom section of intact tissue. 相似文献