全文获取类型
收费全文 | 72篇 |
免费 | 10篇 |
专业分类
林业 | 2篇 |
农学 | 1篇 |
5篇 | |
综合类 | 13篇 |
农作物 | 1篇 |
水产渔业 | 3篇 |
畜牧兽医 | 52篇 |
植物保护 | 5篇 |
出版年
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 1篇 |
2013年 | 11篇 |
2012年 | 6篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有82条查询结果,搜索用时 31 毫秒
1.
Journal of Crop Science and Biotechnology - Since phosphite (Phi) cannot replace phosphate (Pi) as source of phosphorus (P) for plants, and grain crops might experience P deficiency after anthesis,... 相似文献
2.
3.
Stevenson KP Kimmel GA Dohnalek Z Smith RS Kay BD 《Science (New York, N.Y.)》1999,283(5407):1505-1507
The morphology of amorphous solid water grown by vapor deposition was found to depend strongly on the angular distribution of the water molecules incident from the gas phase. Systematic variation of the incident angle during deposition using a collimated beam of water led to the growth of nonporous to highly porous amorphous solid water. The physical and chemical properties of amorphous solid water are of interest because of its presence in astrophysical environments. The ability to control its properties in the laboratory may shed light on some of the outstanding conflicts related to this important material. 相似文献
4.
5.
S E Kimmel R J Washabau K J Drobatz 《Journal of the American Veterinary Medical Association》2001,219(8):1105-1109
OBJECTIVE: To determine the incidence and prognostic significance of low plasma ionized calcium concentration in cats with clinical signs of acute pancreatitis (AP). DESIGN: Retrospective study. ANIMALS: 46 cats with AP and 92 control cats with nonpancreatic diseases. PROCEDURE: Medical records were reviewed, and results of clinicopathologic testing, including plasma ionized and total calcium concentrations, acid-base values, and electrolyte concentrations, were recorded. Cats with AP were grouped on the basis of outcome (survived vs died or were euthanatized), and plasma ionized calcium concentrations, acid-base values, and electrolyte concentrations were compared between groups. RESULTS: Serum total calcium concentration was low in 19 (41%) cats with AP, and plasma ionized calcium concentration was low in 28 (61%). Cats with AP had a significantly lower median plasma ionized calcium concentration (1.07 mmol/L) than did control cats (1.12 mmol/L). Nineteen (41%) cats with AP died or were euthanatized; these cats had a significantly lower median plasma ionized calcium concentration (1.00 mmol/L) than did cats that survived (1.12 mmol/L). Ten of the 13 cats with AP that had plasma ionized calcium concentrations < or = 1.00 mmol/L died or were euthanatized. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that low plasma ionized calcium concentration is common in cats with AP and is associated with a poorer outcome. A grave prognosis and aggressive medical treatment are warranted for cats with AP that have a plasma ionized calcium concentration < or = 1.00 mmol/L. 相似文献
6.
7.
8.
AIM: To compare the prevalence of dilated cardiomyopathy (DCM) in New Zealand Huntaway dogs with the prevalence of DCM in other breeds of dog. METHODS: The necropsy database at Massey University was used to identify cases of DCM diagnosed between January 1999 and March 2006. Dogs were considered to have DCM if echocardiographic, gross necropsy, or histological findings were consistent with this diagnosis. The prevalence in Huntaways was then compared with the prevalence observed in all breeds of dog, as well as the prevalence observed in large breeds of dog. RESULTS: Twelve dogs were identified with DCM. One was diagnosed using echocardiography, while the other 11 were diagnosed by gross necropsy examination. The gross diagnosis of DCM was confirmed histologically in 6/11 dogs. The prevalence of DCM in Huntaways was significantly higher than the prevalence seen in all breeds of dog (p=0.008), and the prevalence in large breeds of dog (p=0.025). All four Huntaways diagnosed with DCM were male, and had an average age of 4 years. Three dogs presented with symptoms attributable to impaired heart function while one presented with symptoms of chronic renal failure. The duration of clinical symptoms prior to presentation ranged between 1 day and 3 weeks. CONCLUSIONS: The results of this study suggest that Huntaways may be predisposed to the development of DCM. Although the increased prevalence in this breed was significant, only small numbers of affected Huntaways were identified, and additional cases are required to confirm these preliminary findings. CLINICAL RELEVANCE: Huntaways are the most common working dog in New Zealand. The premature loss of a working dog is expected to have a significant economic impact on farmers. Further investigation of DCM in Huntaways may allow measures to reduce the prevalence in this breed. 相似文献
9.
ABSTRACTAims: To determine if an ELISA for measurement of IgA in equine serum could be used to measure concentrations of IgA in foal faeces and to determine correlations with concentrations in the milk of the dam.Methods: Faeces from 20 Welsh Cob and Welsh Pony foals and milk from their dams were collected within 12?hours (Day 0) and at 6 days after parturition (Day 6). On Day 6, faeces could not be collected from 2/20 foals, and milk samples could not be collected from 3/20 mares. An equine IgA ELISA validated for serum and plasma was used to measure concentrations of IgA in all samples in triplicate. The precision of the assay for each sample type was determined using modified CV.Results: IgA was not detectable in 7/20 Day 0 faecal samples and in 2/18 Day 6 faecal samples. For samples with detectable IgA, the mean modified CV was 10.5 (95% CI?=?6.0–15.0)% for Day 0 faecal samples, and was 6.8 (95% CI?=?4.3–9.4)% for Day 6 faecal samples. Median concentrations of IgA in faeces on Day 0 were lower than concentrations on Day 6 (0.7?mg/g vs. 37?mg/g dry matter; p?=?0.003). Concentrations of IgA in milk and faeces on Day 6 were statistically correlated (r?=?0.59; p?=?0.006).Conclusions and clinical relevance: The IgA ELISA showed acceptable precision when used to estimate concentrations of IgA in foal faeces during the first week of life, but IgA could not be detected in 37% of meconium samples collected on Day 0. This assay may be useful for investigation of the role of maternal milk IgA in the gastrointestinal tract of neonatal foals, but further assessment of both accuracy and precision of the ELISA is required. 相似文献
10.
N Ge CM Wong RL Lingle JD McNeill KJ Gaffney CB Harris 《Science (New York, N.Y.)》1998,279(5348):202-205
The dynamics of two-dimensional small-polaron formation at ultrathin alkane layers on a silver(111) surface have been studied with femtosecond time- and angle-resolved two-photon photoemission spectroscopy. Optical excitation creates interfacial electrons in quasi-free states for motion parallel to the interface. These initially delocalized electrons self-trap as small polarons in a localized state within a few hundred femtoseconds. The localized electrons then decay back to the metal within picoseconds by tunneling through the adlayer potential barrier. The energy dependence of the self-trapping rate has been measured and modeled with a theory analogous to electron transfer theory. This analysis determines the inter- and intramolecular vibrational modes of the overlayer responsible for self-trapping as well as the relaxation energy of the overlayer molecular lattice. These results for a model interface contribute to the fundamental picture of electron behavior in weakly bonded solids and can lead to better understanding of carrier dynamics in many different systems, including organic light-emitting diodes. 相似文献