全文获取类型
收费全文 | 176篇 |
免费 | 2篇 |
专业分类
林业 | 4篇 |
农学 | 11篇 |
41篇 | |
综合类 | 30篇 |
农作物 | 7篇 |
水产渔业 | 13篇 |
畜牧兽医 | 65篇 |
植物保护 | 7篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 14篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1997年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 4篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1957年 | 1篇 |
1952年 | 1篇 |
1938年 | 1篇 |
1937年 | 1篇 |
1935年 | 1篇 |
1929年 | 1篇 |
1926年 | 1篇 |
1917年 | 1篇 |
1904年 | 1篇 |
1900年 | 1篇 |
排序方式: 共有178条查询结果,搜索用时 31 毫秒
151.
Virk S. S. Porter W. M. Li C. Rains G. C. Snider J. L. Whitaker J. R. 《Precision Agriculture》2021,22(3):777-799
Precision Agriculture - Maintaining adequate planter downforce is critical for achieving timely and uniform crop emergence across the field. On-farm research studies were conducted in different... 相似文献
152.
153.
Bannoehr J Brown JK Shaw DJ Fitzgerald RJ van den Broek AH Thoday KL 《Veterinary dermatology》2012,23(2):119-24, e26
The Gram-positive bacterium Staphylococcus pseudintermedius is regarded as the major cause of canine bacterial pyoderma. Despite its clinical importance, there is only very limited knowledge about the pathogenesis of S. pseudintermedius infection and the specific bacterial virulence factors involved in causing disease. Using a whole-genome approach, we have previously identified 18 predicted cell-wall-anchored surface proteins representing possible virulence factors in a clinical isolate of S. pseudintermedius (strain ED99). They were designated S. pseudintermedius surface proteins A-R (SpsA-SpsR). The present study tested three of the putative Sps proteins (SpsD, SpsL and SpsO) for their ability to mediate adherence of bacteria to canine corneocytes. The three proteins were expressed on the surface of the nonpathogenic surrogate host Lactococcus lactis, a Gram-positive bacterium that does not adhere to canine corneocytes. Adherence assays were performed using corneocytes from different healthy canine donors (n = 5), and bacterial cells were quantified using computerized image analysis. Two of the proteins, SpsD and SpsO, mediated adherence of L. lactis to canine corneocytes, suggesting that they contribute to S. pseudintermedius pathogenesis and may represent novel therapeutic targets to combat infection. 相似文献
154.
155.
Incidence of lameness in dairy cows 总被引:2,自引:0,他引:2
A survey of the number of treatments for lameness in 21,000 dairy cows from 185 herds in the University of Edinburgh/Dalgety Spillers dairy herd health and productivity service in England and Wales showed an average incidence of cases of 25 per cent. Veterinary surgeons treated 6.3 per cent and farmers 18.7 per cent and 1.4 per cent of cows were culled because of lameness. Monthly and regional variations were recorded. An assessment of the economic effects suggested that the average annual cost in a 100 cow herd was 1175 pounds with an overall cost to British farmers of more than 35 million pounds. The economic importance is such that research into specific factors affecting foot health should be carried out. Meanwhile, a broad approach to prevention and control of lameness on farms is recommended under the general headings of management/environment, nutrition and breeding. 相似文献
156.
No effect of a dietary zinc proteinate on clinical mastitis,infection rate,recovery rate and somatic cell count in dairy cows 总被引:1,自引:0,他引:1
Whitaker DA Eayres HF Aitchison K Kelly JM 《Veterinary journal (London, England : 1997)》1997,153(2):197-203
Forty dairy cows, paired at drying off according to expected calving date, milk somatic cell count (SCC) and previous mastitis history, and 10 heifers, paired by date of expected calving, were fed diets in the last 3 weeks of pregnancy which contained either 200 mg zinc proteinate and 60 mg inorganic zinc (Zinc group), or 260 mg inorganic zinc (Control group) per day in addition to the natural content of their feeds. After calving, the Zinc group each received 250 mg zinc proteinate and 140 mg inorganic zinc and the Control group 390 mg inorganic zinc per day above background levels. During the first 100 days of lactation there were no significant differences between the groups in terms of clinical mastitis rates, mastitis caused by environmental organisms, new infection rates or recovery rates. SCC showed no differences between the groups. Monitoring of body condition score and weight change, milk yield, blood metabolite values and fertility showed satisfactory and similar nutrition and productivity in both groups. The trial did not demonstrate any advantages from feeding proteinates to dairy cows and highlights the general absence of published controlled trial data on the subject. 相似文献
157.
John R. Stommel Marija Pushko Kathleen G. Haynes Bruce D. Whitaker 《Plant Breeding》2014,133(6):788-793
Colour is a critical determinant of fruit and vegetable quality. We characterized the inheritance of black and violet immature pepper fruit colour and chlorophyll, carotenoid and anthocyanin pigments responsible for fruit colour. Segregation for black vs. violet fruit colour deviated from expectations for simple inheritance. The primary determinant of fruit colour was the concentration of chlorophyll and carotenoid pigments relative to anthocyanin concentration. Whereas anthocyanin concentration was 34% greater in violet fruit, chlorophyll and carotenoid concentrations were 20‐fold and fourfold greater, respectively, in black fruit relative to concentrations found in violet fruit. Measurement of Commission Internationale d'Eclairage (CIE) colour space scores revealed larger a* values and smaller b* values for violet fruit relative to corresponding parameters for black fruit. An additive–dominance model was sufficient to explain the variation in individual fruit pigments as well as the CIE parameter a*. Addition of additive × additive effects to the additive–dominance model resulted in the best‐fit model m[d][h][i] for L* and b* colour space parameters. For all pigment classes, significant additive effects contributed to the genetic variance for fruit colour. 相似文献
158.
159.
160.