全文获取类型
| 收费全文 | 894篇 |
| 免费 | 73篇 |
专业分类
| 林业 | 48篇 |
| 农学 | 29篇 |
| 基础科学 | 3篇 |
| 112篇 | |
| 综合类 | 144篇 |
| 农作物 | 24篇 |
| 水产渔业 | 50篇 |
| 畜牧兽医 | 479篇 |
| 园艺 | 32篇 |
| 植物保护 | 46篇 |
出版年
| 2022年 | 5篇 |
| 2021年 | 17篇 |
| 2020年 | 16篇 |
| 2019年 | 21篇 |
| 2018年 | 25篇 |
| 2017年 | 25篇 |
| 2016年 | 22篇 |
| 2015年 | 14篇 |
| 2014年 | 19篇 |
| 2013年 | 39篇 |
| 2012年 | 46篇 |
| 2011年 | 57篇 |
| 2010年 | 31篇 |
| 2009年 | 29篇 |
| 2008年 | 36篇 |
| 2007年 | 59篇 |
| 2006年 | 49篇 |
| 2005年 | 41篇 |
| 2004年 | 42篇 |
| 2003年 | 39篇 |
| 2002年 | 34篇 |
| 2001年 | 14篇 |
| 2000年 | 12篇 |
| 1999年 | 13篇 |
| 1998年 | 10篇 |
| 1996年 | 8篇 |
| 1992年 | 7篇 |
| 1991年 | 8篇 |
| 1990年 | 5篇 |
| 1989年 | 5篇 |
| 1988年 | 10篇 |
| 1987年 | 8篇 |
| 1986年 | 10篇 |
| 1985年 | 9篇 |
| 1984年 | 9篇 |
| 1983年 | 7篇 |
| 1979年 | 9篇 |
| 1978年 | 5篇 |
| 1977年 | 5篇 |
| 1975年 | 8篇 |
| 1974年 | 7篇 |
| 1973年 | 10篇 |
| 1972年 | 6篇 |
| 1971年 | 13篇 |
| 1969年 | 9篇 |
| 1967年 | 9篇 |
| 1966年 | 4篇 |
| 1886年 | 4篇 |
| 1885年 | 5篇 |
| 1884年 | 4篇 |
排序方式： 共有967条查询结果，搜索用时 31 毫秒
1.
Battison AL Buczkowski S Archer FJ 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1996,25(2):43-47
A reference interval for plasma glutamate dehydrogenase (GD) (E.C. 1.4.1.3) activity, of 0-8 IU/L, was established for the cockatiel (Nymphicus hollandicus). An automated modification of a commercial manual assay was used. This enzyme is considered liver specific in humans and numerous domestic animals, due to its organ distribution. A similar distribution was found in cockatiels in this study. Maximal enzyme activity was recovered from liver and kidney homogenate supernatants. Minimal activity was detected in skeletal muscle preparations. These results suggest a potential use for plasma GD activity in the evaluation of hepatocelluar injury/necrosis in cockatiels. 相似文献
2.
In controlled environment experiments, sporulation of Pyrenopeziza brassicae was observed on leaves of oilseed rape inoculated with ascospores or conidia at temperatures from 8 to 20°C at all leaf wetness durations from 6 to 72 h, except after 6 h leaf wetness duration at 8°C. The shortest times from inoculation to first observed sporulation ( l 0 ), for both ascospore and conidial inoculum, were 11–12 days at 16°C after 48 h wetness duration. For both ascospore and conidial inoculum (48 h wetness duration), the number of conidia produced per cm2 leaf area with sporulation was seven to eight times less at 20°C than at 8, 12 or 16°C. Values of Gompertz parameters c (maximum percentage leaf area with sporulation), r (maximum rate of increase in percentage leaf area with sporulation) and l 37 (days from inoculation to 37% of maximum sporulation), estimated by fitting the equation to the observed data, were linearly related to values predicted by inserting temperature and wetness duration treatment values into existing equations. The observed data were fitted better by logistic equations than by Gompertz equations (which overestimated at low temperatures). For both ascospore and conidial inoculum, the latent period derived from the logistic equation (days from inoculation to 50% of maximum sporulation, l 50 ) of P. brassicae was generally shortest at 16°C, and increased as temperature increased to 20°C or decreased to 8°C. Minimum numbers of spores needed to produce sporulation on leaves were ≈25 ascospores per leaf and ≈700 conidia per leaf, at 16°C after 48 h leaf wetness duration. 相似文献
3.
D.J. Robinson M.F.B. Dale D. Todd 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(9):921-928
Infection of potato plants with Tobacco rattle virus by its nematode vector can have different outcomes, including the development of spraing symptoms in progeny tubers. A novel syndrome described here comprises a generalized mottle in leaves on all stems, together with virtually total failure to produce daughter tubers. The outcome of infection depends partly on the potato genotype, but field trials with 15 varieties showed that the incidence and severity of spraing symptoms at three sites differed. There was no evidence that this was due to differences in virulence among the virus isolates at the sites, but it was probably the result of environmental differences that influenced the numbers and activity of the vector nematodes. At the most severely affected site, spraing symptoms were found in all varieties tested, except Record, including several that were not affected at the other two sites. Taking both severity and incidence of symptoms into account, the ranking of varieties was similar at each site. The incidence of spraing symptoms was greater in larger than in smaller tubers, and increased with later harvest dates, but did not increase when early harvested tubers were stored. Tobacco rattle viruswas detected in the roots of many of the weeds growing at one of the sites and in the roots of a few plants of the subsequent barley crop. 相似文献
4.
Five horses with a primary surgical lesion of the small (descending) colon were diagnosed with eosinophilic colitis based on visual and histopathological examination. These were evident as visibly striking, hyperaemic, focal lesions of the small colon, with serosal petechiation, oedema and marked thickening of the intestinal wall at the site. Areas of focal necrosis were also evident. The gross appearance of the lesions were considered to be sufficiently severe in all cases to merit resection, due to concerns about intestinal necrosis and septic peritonitis. An inability to fully exteriorise the affected portion of intestine to perform a resection and anastomosis necessitated intraoperative euthanasia of one horse. A total of three horses survived to hospital discharge. Eosinophilic colitis lesions are a rare cause of severe small colon disease, but should be considered in cases with similar visual characteristics. 相似文献
5.
Kelsey T. Young Kevin K. Lahmers Holly S. Sellers David E. Stallknecht Rebecca L. Poulson Jerry T. Saliki Stephen Mark Tompkins Ian Padykula Chris Siepker Elizabeth W. Howerth Michelle Todd James B. Stanton 《Journal of veterinary diagnostic investigation》2021,33(2):202
RNA viruses rapidly mutate, which can result in increased virulence, increased escape from vaccine protection, and false-negative detection results. Targeted detection methods have a limited ability to detect unknown viruses and often provide insufficient data to detect coinfections or identify antigenic variants. Random, deep sequencing is a method that can more fully detect and characterize RNA viruses and is often coupled with molecular techniques or culture methods for viral enrichment. We tested viral culture coupled with third-generation sequencing for the ability to detect and characterize RNA viruses. Cultures of bovine viral diarrhea virus, canine distemper virus (CDV), epizootic hemorrhagic disease virus, infectious bronchitis virus, 2 influenza A viruses, and porcine respiratory and reproductive syndrome virus were sequenced on the MinION platform using a random, reverse primer in a strand-switching reaction, coupled with PCR-based barcoding. Reads were taxonomically classified and used for reference-based sequence building using a stock personal computer. This method accurately detected and identified complete coding sequence genomes with a minimum of 20× coverage depth for all 7 viruses, including a sample containing 2 viruses. Each lineage-typing region had at least 26× coverage depth for all viruses. Furthermore, analyzing the CDV sample through a pipeline devoid of CDV reference sequences modeled the ability of this protocol to detect unknown viruses. Our results show the ability of this technique to detect and characterize dsRNA, negative- and positive-sense ssRNA, and nonsegmented and segmented RNA viruses. 相似文献
6.
Nutritional analysis and microbiological evaluation of commercially available enteral diets for cats 
下载免费PDF全文
下载免费PDF全文 7.
8.
9.
10.