全文获取类型
收费全文 | 151篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
林业 | 11篇 |
农学 | 3篇 |
28篇 | |
综合类 | 20篇 |
农作物 | 2篇 |
水产渔业 | 2篇 |
畜牧兽医 | 81篇 |
园艺 | 10篇 |
植物保护 | 5篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2010年 | 8篇 |
2009年 | 2篇 |
2008年 | 7篇 |
2007年 | 14篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1947年 | 1篇 |
排序方式: 共有162条查询结果,搜索用时 15 毫秒
121.
Bartges J Boynton B Vogt AH Krauter E Lambrecht K Svec R Thompson S 《Journal of the American Animal Hospital Association》2012,48(1):1-11
Guidelines are offered to guide the veterinary practitioner in designing a comprehensive, individualized wellness plan for each stage of a dog's life. Life stages are defined by both age and breed characteristics for practical purposes. Each patient visit should use an individualized approach to patient handling, preventive care, and early disease detection. Environment, behavior, nutrition, parasite control, vaccinations, dental care, zoonotic disease control, safety, and reproductive health should be addressed. 相似文献
122.
Summary Two fibre plants are under cultivation in the European Union – flax on approximately 125,000 ha and hemp on approximately 15,500 ha in the year 2004. Seeds, hurds and especially fibres of hemp are used for further processing. The most important markets for hemp fibres produced in the EU are pulp and paper and the automotive industry. Just under 5% of the EU hemp fibres were used in the construction sector. Approximately 95% the whole production of 40,000 t of the hemp hurds are used as animal bedding and 95% of the estimated 6000 t per year hemp seeds are sold for animal feed, mainly as bird feed. 相似文献
123.
D Schimmel Z Pospisil I Schimmel F Schulze A Vogt 《Archiv fuer experimentelle veterinaermedizin》1977,31(1):15-27
Store pigs with spontaneous outbreaks and experimental endotoxin shock were kept under observation in the context of coagulation analysis. Heparin was applied to some of the animals to disrupt the plasmatic coagulation system. The thrombocyte count in animals with endotoxin infusion declined by some 50 to 65 percent of the original level. No statistically secured difference was found to exist between heparinised animals, on the one hand, and non-heparinised, on the other. The aggregation and adhesion of thrombocytes in all shock animals was more pronounced than that in the controls. The fibrinogen levels were lowered in both the animals with spontaneous outbreaks and the experimental animals. Thrombocyte alteration was not found to have been dependent on activation of the plasmatic coagulation system. In endotoxin shock cases activation of plasmatic coagulation proteins was found to be preceded by rise in thrombocyte aggregation. 相似文献
124.
Scheer-Czechowski P Vogt HR Tontis A Peterhans E Zanoni R 《Schweizer Archiv für Tierheilkunde》2000,142(4):155-164
Maedi-Visna is a lentiviral disease of sheep with a worldwide distribution. The transmission of the virus occurs primarily via colostrum and milk from the infected ewe to its newborn lamb but also horizontally between sheep. The most obvious clinical symptoms are progressive dyspnea and emaciation. In this prospective study an eradication based on serological testing and removing of seropositive animals was performed in 24 flocks of sheep of the breed "Walliser Schwarznasenschafe" leading to a reduction of the seroprevalence from 36% to 1% within two years. The control group consisted of 21 flocks of sheep. Lambs of seropositive ewes had a 7.6 times higher risk to seroconvert within their first two years of life compared to those of seronegative ewes. The dynamics of the spread of the infection were studied in birth cohort groups. Cohort animals of seropositive ewes showed an obvious trend to seroconvert slowly. Seropositive ewes had a significantly lower reproduction rate and their lambs suffered from significantly higher death and lower growth rates, probably due to a reduced milk production, resulting in economic losses. 相似文献
125.
The chromosomes of a porcine cyclops were examined after a culture was made of tissue from one kidney. The 2n number of chromosomes was 38,XX, with no apparent deviations from that of a normal female swine. Possible factors contributing to this abnormality are discussed. 相似文献
126.
127.
MI Giassetti MD Goissis FRO de Barros AH Bruno MEOA Assumpção JA Visintin 《Reproduction in domestic animals》2016,51(1):26-32
Spermatogonial stem cells (SSC) have important applications in domestic animal reproduction and advanced biotechnologies. Because differential plating is one of the most common methods used for SSC enrichment, the goal of this study was to compare three differential plating methods for the enrichment of bovine SSC. To achieve this goal, testicular parenchyma from pre‐pubertal calves was minced and single cells were obtained after two enzymatic digestions. We compared three coating methods for differential plating: laminin (20 ng/ml), BSA (0.05 mg/ml) and PBS. Cells were incubated at 37°C, 5% CO2 in air for 15 min onto laminin‐coated dishes or 2 h onto BSA‐ or PBS‐coated dishes. Cell viability was assessed by trypan blue exclusion method. Recovered cells were analysed for the expression of SSC molecular markers by quantitative RT‐PCR (GFRA1, CXCR4, ITGA6, THY1) and flow cytometry (GFRA1, CXCR4 and ITGA6). Cells at time 0, adherent cells on laminin and non‐adherent cells from BSA and PBS groups had the same cell viability (p = 0.0655). GFRA1, CXCR4 and THY1 relative gene expression was higher (p = 0.0402, p = 0.0007, p = 0.0117, respectively) for non‐adherent cells selected in PBS group. Flow cytometry analysis revealed that the presence of GFRA‐positive (GFRA+) cells was higher in non‐adherent cells from BSA and PBS groups (p < 0.001). However, laminin‐adherent cells had higher number of ITGA6+ cells (p < 0.001) and lower presence of CXCR4+ cells (p = 0.0012). In conclusion, differential plating is an effective method for the enrichment of bovine undifferentiated spermatogonia and higher expression of SSC markers is obtained without laminin or BSA coating. 相似文献
128.
129.
130.
Vogt RE Chenette DL Cummings AC Garrard TL Stone EC Schardt AW Trainor JH Lal N McDonald FB 《Science (New York, N.Y.)》1982,215(4532):577-582
Results from the cosmic-ray system on Voyager 2 in Saturn's magnetosphere are presented. During the inbound pass through the outer magnetosphere, the >/= 0.43-million-electron-volt proton flux was more intense, and both the proton and electron fluxes were more variable, than previously observed. These changes are attributed to the influence on the magnetosphere of variations in the solar wind conditions. Outbound, beyond 18 Saturn radii, impulsive bursts of 0.14- to > 1.0- million-electron-volt electrons were observed. In the inner magnetosphere, the charged particle absorption signatures of Mimas, Enceladus, and Tethys are used to constrain the possible tilt and offset of Saturn's internal magnetic dipole. At approximately 3 Saturn radii, a transient decrease was observed in the electron flux which was not due to Mimas. Characteristics of this decrease suggest the existence of additional material, perhaps another satellite, in the orbit of Mimas. 相似文献