全文获取类型
收费全文 | 192篇 |
免费 | 10篇 |
专业分类
林业 | 25篇 |
农学 | 2篇 |
24篇 | |
综合类 | 31篇 |
农作物 | 1篇 |
水产渔业 | 3篇 |
畜牧兽医 | 95篇 |
园艺 | 1篇 |
植物保护 | 20篇 |
出版年
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 16篇 |
2011年 | 12篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 6篇 |
2005年 | 10篇 |
2004年 | 2篇 |
2003年 | 10篇 |
2002年 | 5篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1976年 | 3篇 |
1973年 | 3篇 |
1972年 | 5篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 4篇 |
1963年 | 1篇 |
1947年 | 2篇 |
排序方式: 共有202条查询结果,搜索用时 15 毫秒
131.
In this investigation trichomonads were isolated from the oral cavity in 21 of 110 examined cats, and only from those which were simultaneously FeLV, FIV or FIP positive. By means of scanning electron microscopy the trichomonads were shown to be round or piriform parasites which were on average 7.9 microns long and 6.2 microns wide at maximum width. They had 4 anterior flagella, which were on average 9.4 microns long, an undulating membrane measuring 6.7 microns with no trailing flagellum as well as an axostyle extending on average 5.0 microns beyond the body, and therefore should be attributed to the genus Trichomonas. 相似文献
132.
Klaus C Beer M Saier R Schubert H Bischoff S Süss J 《Berliner und Münchener tier?rztliche Wochenschrift》2011,124(11-12):443-449
Tick-borne encephalitis (TBE) in animals is not well understood yet. TBE virus (TBEV) serology in several host species could be valuable for epidemiological analyses in the field as well as for the detection of clinical cases. However, performance and suitability of the available test systems are not well assessed. Therefore, we evaluated two commercial TBEV-ELISA kits in a pilot study and compared them for their suitability in veterinary applications. For this purpose, we tested 163 field collected goat sera and evaluated the results by serum neutralization test (SNT) as "gold standard". Twenty-eight SNT positive sera (17.2%) were detected. The best suited ELISA kit was used for determination of a species-specific cutoff for horses, cattle, sheep, goats, pigs, mice, dogs, rabbits and monkeys with defined sera from animals without known or with improbable contact to TBEV. The level of non-specific ELISA results does not only differ between animal species but may also be influenced by the age of the tested animals. The number of sera which tested false positive by ELISA was higher in older than in young sheep. In order to obtain defined polyclonal sera as references, two dogs, cattle, goats, sheep, rabbits and pigs each, as well as one horse and 90 mice were immunized four times with a commercially available TBEV vaccine. In conclusion, our results demonstrated that commercial TBEV-ELISA kits are suitable for application in veterinary medicine for both, verification of clinical TBE cases and epidemiological screening. However, positive ELISA results should be verified by SNT. Only a very low number of false negative ELISA-results were found. 相似文献
133.
Said A Damiani A Ma G Kalthoff D Beer M Osterrieder N 《Veterinary microbiology》2011,154(1-2):113-123
In 2009, a novel swine-origin H1N1 influenza A virus (S-OIV), antigenically and genetically divergent from seasonal H1N1, caused a flu pandemic in humans. Development of an effective vaccine to limit transmission of S-OIV in animal reservoir hosts and from reservoir hosts to humans and animals is necessary. In the present study, we constructed and evaluated a vectored vaccine expressing the H1 hemagglutinin of a recent S-OIV isolate using equine herpesvirus 1 (EHV-1) as the delivery vehicle. Expression of the recombinant protein was demonstrated by immunofluorescence and western blotting and the in vitro growth properties of the modified live vector were found to be comparable to those of the parental virus. The EHV-1-H1 vaccine induced an influenza virus-specific antibody response when inoculated into mice by both the intranasal and subcutaneous routes. Upon challenge infection, protection of vaccinated mice could be demonstrated by reduction of clinical signs and faster virus clearance. Our study shows that an EHV-1-based influenza H1N1 vaccine may be a promising alternative for protection against S-OIV infection. 相似文献
134.
A pet rat derived cowpox virus strain, which was also the source of human infections, was used to infect young Wistar and fancy rats. After an incubation period of 6 days the animals developed a severe, often fatal disease with high amounts of virus detected in oropharyngeal secretions. 相似文献
135.
Sovan Debnath Raj Narayan Anil Kumar Arun Kishor Desh Beer Singh 《Soil Science and Plant Nutrition》2020,66(3):489-498
ABSTRACT Soil fertility in many parts of the north?western Himalayan region (NWHR) has declined owing to accelerated nutrient mining under existing crop regime. Therefore, this study aimed to assess effect of the predominant horticulture?based land uses on soil fertility and health in mid and high hills of NWHR. Soil samples (0?20 cm) were collected, analyzed for different soil chemical attributes (pH, electrical conductivity, organic C, available primary-, secondary-, and micro-nutrients), and compared across five key land uses: perennial grass (PG), peach orchard (PO), apple orchard (AO), field vegetable farming (VF), and protected vegetable farming (PV). Soils of the investigated land uses were neutral to near neutral in soil reaction (6.3?6.8) except field vegetable and protected vegetable farming. Amount of soil organic C and labile organic C was significantly higher (p ≤ 0.05) in soils of apple orchards (18.6 g kg?1 and 687.3 mg kg?1, respectively) and peach orchards (20.4 g kg?1 and 731.3 mg kg?1, respectively) over others. An abrupt and significant increase in Olsen-P was recorded in soils of field vegetable farming (17.1 mg kg?1) and protected vegetable farming (13.0 mg kg?1), which shifted their nutrient index (NI) of P in to high category (≥ 2.33). The concentration of mineralizable-N in soil was statistically at par in soils under perennial grass and fruit orchards, while protected vegetable farming showed maximum soil mineralizable-N content (115.5 mg kg?1) and NI of nitrogen (1.83). The NI was in high category (≥ 2.33) for copper, iron, and manganese in majority of the land uses. In view of the results, temperate fruit?tree based land uses are benign in up?keeping soil fertility and soil health, and needs promotion on large scale. Additionally, policies to create incentives for the build-up of soil organic matter and replenishment of the depleted soil macro and micro nutrients in vegetable-farmed lands are warranted. 相似文献
136.
Im 5. bis 8. Nutzungsjahr (1987 bis 1990) erreichten standortangepaßte Gräsermischungen mit tragendem Saatpartner Alopecurus pratensis bzw. Phalaris arundinacea sowie Bromus inermis unter Beregnung in der Regel gesicherte Mehrerträge an Trockensubstanz. Auch die Ertragsverteilung zwischen den einzelnen Aufwüchsen dieser Bestände konnte durch Zusatzwasser deutlich ausgeglichener gestaltet werden. Zwischen den verschiedenen Saatverfahren waren kaum noch signifikante Ertragsunterschiede festzustellen. 相似文献
137.
Claire Ponsart Nathalie Pozzi Emmanuel Bréard Virginie Catinot Guillaume Viard Corinne Sailleau Cyril Viarouge Julie Gouzil Martin Beer Stéphan Zientara Damien Vitour 《Veterinary research》2014,45(1):37
Schmallenberg virus (SBV) is a novel orthobunyavirus, discovered in Germany in late 2011. It mainly infects cattle, sheep and goats and could lead to congenital infection, causing abortion and fetal abnormalities. SBV is transmitted by biting midges from the Culicoides genus and there is no evidence that natural infection occurs directly between ruminants. Here, we could detect SBV RNA in infected bull semen using qRT-PCR (three bulls out of seven tested positive; 29 positive semen batches out of 136). We also found that highly positive semen batches from SBV infected bulls can provoke an acute infection in IFNAR-/- mice, suggesting the potential presence of infectious virus in the semen of SBV infected bulls. 相似文献
138.
Geostatistical modeling of the spatial variability of coffee fine roots under Erythrina shade trees and contrasting soil management 总被引:1,自引:0,他引:1
Spatial relationships between root length density of Coffea arabica (coffee RLD) and soil nutrient- related factors at plot scale in a coffee- Erythrina poeppigiana system was studied by geostatistics. In a 24 × 29 m area, (organic and conventional management), coffee and Erythrina fine roots and soil chemical properties were sampled on an irregular grid in the topsoil. A factor analysis explained 83 % of the total variation of the soil attributes. Soil factors were identified: Chemical fertility (CF), Micronutrients, Organic matter, and Acidity (Ac). Based on the spherical model, all the attributes presented a strong spatial structure. The scale of spatial correlation for CF was lesser than for Ac, but similar to coffee RLD. Erythrina RLD had a short-range variation. Patchy areas of high spots of coffee RLD were greater in organic plot. Cross-semivariogram analysis estimated a correlation between soil factors and coffee RLD over a scale of 5.50 m; but 4.23 m with Erythrina RLD. Nutrients linked to P, Zn, exchangeable bases and acidity soil affected the scale of spatial aggregation pattern of coffee RLD. The spatial response of coffee RLD suggests a differential nutrient uptake strategy for acquiring soil nutrients induced by the quality of organic and inorganic fertilizer inputs. The fact that coffee RLD had higher scale of spatial variation than Erythrina RLD and a negative spatial correlation indicate that pruned Erythrina trees are not so competitive for acquiring shared nutrients in an agroforestry system. 相似文献
139.
Trapp S Beer M Mettenleiter TC 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(5-6):171-178
Cattle are the natural host of herpesviruses. Since now four different bovine viruses have been described as members of the family Herpesviridae. The prototype of the bovine herpesviruses, Bovine Herpesvirus type 1 (BHV-1), is the causative agent of infectious bovine rhinotracheitis (IBR), infectious pustular vulvovaginitis (IPV) and infectious balanoposthitis (IBP). The related BHV-5 is an exotic neurovirulent agent and like BHV-1 a member of the genus Varicellovirus, within the subfamily Alphaherpesvirinae. BHV-2, also an alphaherpesvirus but grouped into the genus Simplexvirus is the causative agent of bovine herpes mammilitis and pseudolumpy skin disease. In contrast, BHV-4, a member of the subfamily Gammaherpesvirinae, is not known to cause any disease. Beside bovine herpesviruses there are few other herpesviruses which can infect cattle. Infections of cattle with these herpesviruses have either clinical or diagnostic importance, based on a close antigenic relationship to BHV-1 of some ruminant herpesviruses. This article deals with the molecular virology of bovine herpesviruses and the pathogenesis of bovine herpesvirus infections and provides an overview over herpesviruses that can infect cattle. 相似文献
140.
Beer M König P Schielke G Trapp S 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(5-6):183-191
The usage of glycoprotein E (gE)-deleted BHV-1 marker or DIVA (differentiating infected from vaccinated animals) vaccines in combination with the accompanying determination of gE-specific antibodies is one of the basic parts of BHV-1 eradication programs in Germany. Following the adoption of the "Legislation for the protection of cattle holdings from an infection with Bovine Herpesvirus Type 1" in 1997, several million gE-antibody assays were conducted. Up to now, commercially available gE-blocking enzyme linked immunosorbent assays (ELISAs) are the only test systems available for the detection of gE-specific antibodies. However, there are some difficulties to meet the high requirements on their performance. Therefore, role and function of gE in the virus and the host as well as the principle of gE marker assays, the test design and the capability of the mainly used ELISAs are illuminated in this paper. Additionally, suggestions concerning the optimal usage and the correct application of gE-blocking-ELISAs are discussed. 相似文献