全文获取类型
收费全文 | 130篇 |
免费 | 10篇 |
专业分类
林业 | 3篇 |
农学 | 3篇 |
9篇 | |
综合类 | 12篇 |
农作物 | 1篇 |
水产渔业 | 3篇 |
畜牧兽医 | 86篇 |
植物保护 | 23篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 13篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1965年 | 1篇 |
1957年 | 1篇 |
1942年 | 1篇 |
1927年 | 1篇 |
1926年 | 1篇 |
1922年 | 1篇 |
1921年 | 2篇 |
1920年 | 1篇 |
1918年 | 1篇 |
排序方式: 共有140条查询结果,搜索用时 0 毫秒
81.
CASE HISTORY: A 6-year-old, spayed, female, domestic short-haired cat presented with severe erythroderma and scaling skin. She showed disturbed gait and mild behavioural changes. CLINICAL FINDINGS: The cat had a generalised, erythematous, scurfy dermatitis with marked, multifocal crusting and skin thickening. The skin was painful and contracted, which appeared to prevent normal freedom of movement. DIAGNOSIS: The cat was suspected to have a paraneoplastic syndrome. A mediastinal mass was located and histologically confirmed as thymoma. The cat was diagnosed with a thymoma-associated cutaneous paraneoplastic syndrome. CLINICAL RELEVANCE: This is a rare condition with few reports in the literature. The skin changes, both grossly and histologically, were considered to be different from those described in cases of paraneoplastic dermatosis associated with pancreatic neoplasia. The clinical presentation was characteristic and more cases may occur in practice than are recognised. In this case, as in previous reports, the tumour was grossly resectable, which could lead to cure of the clinical condition. 相似文献
82.
83.
N.A.C. Smits M.M. Hefting H.J. Laanbroek A.J. Paalman 《Soil biology & biochemistry》2010,42(4):635-641
Measurements along a hill-slope vegetation gradient in nutrient-poor grasslands from acid grasslands via matgrass swards to calcareous grasslands showed increased ammonium to nitrate ratios in the matgrass swards. These results generated the research question whether there might be a difference in nitrification activity or nitrifying community composition between the different zones in this hill-slope gradient. In each of the vegetation types along the gradient, soil samples were taken in five grassland nature reserves. Potential nitrification rates have been determined as an indication of the size of the active ammonia-oxidising microbial communities. Additionally, the dominant ammonia-oxidising sequences related to the β-Proteobacteria have been determined by a Polymerase Chain Reaction (PCR) based on the 16S rRNA gene in combination with Denaturing Gradient Gel Electrophoresis (DGGE) at one of the nature reserves.Compared to the top and lower zones of the vegetation gradient (i.e. acid grasslands and calcareous grasslands, respectively), potential nitrification rates were clearly repressed in the middle, matgrass swards zone. In contrast to the differences in potential nitrification activities observed in one of the nature reserves (Bemelerberg), no differences in dominant ammonia-oxidising sequences were observed at this location. One sequence belonging to cluster 3 of the Nitrosospira lineage appeared to be dominant among the sequences belonging to the ammonia-oxidising species of the β-Proteobacteria in all vegetation zones. Nitrification was apparently inhibited by the vegetation, whereas no shift in nitrifier populations could be shown. The possible role of repressed nitrification in the decline of this vegetation type is discussed. 相似文献
84.
This study established a disease model and protocol for bacterial challenge with Escherichia coli serogroup O2 strain EC317 in Japanese quail. Five groups of 10 birds each were injected subcutaneously in the breast with 200 μL of a brain-heart infusion (BHI) culture containing 1 × 10(8), 1 × 10(7), 1 × 10(6), 1 × 10(5), or 1 × 10(4) colony-forming units/mL of the test organism, which had been isolated from a turkey with cellulitis and septicemia. Birds in a 6th group were controls that received sterile BHI alone. Localized lesions of cellulitis developed in all of the birds that received E. coli. The morbidity and mortality rates were highest (100%) in the birds receiving the highest dose of E. coli and decreased linearly with decreasing dose (P < 0.05). Severity of disease, including lesions of pericarditis and perihepatitis, was also directly proportional to the dose of E. coli. These findings indicate that this disease challenge protocol can be used to study disease resistance and immunologic consequences of contaminant exposure or other stressors in birds. 相似文献
85.
Supplementing diets with n-3 fatty acids from fish oil has been shown to improve reproductive performance in dairy cattle and sheep, but there is little published literature on its effects in sows. The aim of this study was to evaluate the reproductive performance of sows fed fish oil as a source of n-3 PUFA prefarrowing and during lactation. From d 107.7 ± 0.1 of pregnancy, 328 sows ranging in parity from 0 to 7 (parity 1.95 ± 0.09, mean ± SE) were fed either a diet containing tallow (control) or an isocaloric diet containing 3 g of fish oil/kg of diet (n-3). Diets were formulated to contain the same amount of DE (13.9 MJ/kg), crude fat (54 g/kg), and CP (174 g/kg). Sows were fed their treatment diet at 3 kg daily for 8 d before farrowing and continued on treatment diets ad libitum until weaning at 18.7 ± 0.1 d of lactation. After weaning, all sows were fed a gestation diet without fish oil until their subsequent farrowing. There was no effect (P > 0.310) of feeding n-3 diets prefarrowing on piglet birth weight, preweaning growth rate, piglet weaning weight, or sow feed intake. However, n-3 sows had a larger subsequent litter size (10.7 ± 0.3 vs. 9.7 ± 0.3 total born; 10.2 ± 0.3 vs. 9.3 ± 0.3 born live; P < 0.05). In conclusion, this is the first study to demonstrate that feeding sows a diet containing n-3 PUFA from fish oil fed before farrowing and during lactation increased litter size in the subsequent parity independent of energy intake. 相似文献
86.
87.
88.
89.
90.
Tank-mixtures of selective herbicides were evaluated for 2 years on field-grown sugarbeets under two weed flora situations: (a) mixed floras of broad-leaved and grass weeds and (b) weed floras of broadleaves grown beyond their stages of greatest sensitivity to herbicides. In these situations single herbicides usually fail to provide satisfactory post-emergence weed control in sugarbeets. Of several tank-mixtures, which could be devised for use in the first situation, ethofurnesate + Betanal AM 11, diclofop-methyl + Betanal AM 11 and diclofop-methyl + metamitron gave synergistic phytotoxicity to sugarbeet seedlings. Synergism in weed control, becoming apparent by an accelerated appearance of the herbicidal effects, was obtained with the mixture alloxydimeton + Betanal AM 11. This mixture was not phytotoxic and appears to be the most efficient for simultaneous control of broad-leaved and grass weeds. From trials in the second situation it became apparent that the activity of metamitron, which was reduced on older weeds, could be restored by mixing with a non-phytotoxic oil or a low dose of Betanal AM 11. These mixtures should be useful when growth of sugarbeets has been retarded by carried-over herbicides, drought, frost, etc. 相似文献