全文获取类型
收费全文 | 962篇 |
免费 | 67篇 |
国内免费 | 1篇 |
专业分类
林业 | 72篇 |
农学 | 49篇 |
基础科学 | 5篇 |
280篇 | |
综合类 | 70篇 |
农作物 | 83篇 |
水产渔业 | 108篇 |
畜牧兽医 | 266篇 |
园艺 | 23篇 |
植物保护 | 74篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 27篇 |
2021年 | 33篇 |
2020年 | 39篇 |
2019年 | 26篇 |
2018年 | 50篇 |
2017年 | 46篇 |
2016年 | 42篇 |
2015年 | 35篇 |
2014年 | 54篇 |
2013年 | 57篇 |
2012年 | 62篇 |
2011年 | 83篇 |
2010年 | 40篇 |
2009年 | 47篇 |
2008年 | 67篇 |
2007年 | 55篇 |
2006年 | 52篇 |
2005年 | 46篇 |
2004年 | 27篇 |
2003年 | 48篇 |
2002年 | 32篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有1030条查询结果,搜索用时 0 毫秒
1.
Paolo Zucca Giovanni Di Guardo Roberto Pozzi-Mucelli Dino Scaravelli Marco Francese 《Journal of zoo and wildlife medicine》2004,35(3):391-394
A mature male Risso's dolphin (Grampus griseus) stranded along the coasts of Friuli Venezia Giulia, northeast Italy, in May 2001. Parasitic infection with Crassicauda grampicola is often found in the tympanic bullae and pterygoid sinuses in many of the Risso's dolphins examined from the same area. For this reason, it was decided to perform computed tomography of the head to assess this imaging technique for the diagnosis of crassicaudosis in dolphins. A full postmortem examination confirmed the pathologic findings of the computed tomography scan. This technique can be considered a useful adjunct in the diagnosis of cranial crassicaudosis in live dolphins. 相似文献
2.
3.
Natoli E Maragliano L Cariola G Faini A Bonanni R Cafazzo S Fantini C 《Preventive veterinary medicine》2006,77(3-4):180-185
In Italy, which is rabies-free, the national Law No. 281 [Legge Nazionale 14 agosto 1991. No. 281: Legge Quadro in materia di animali di affezione e prevenzione del randagismo. Gazz. Uff. Rep. Ital. no 203 del 30 agosto 1991: p. 3] on the management of pets and on the control of feral cats has introduced the no-kill policy for this species. Thus, “trap-neuter-release” (TNR) programs have been carried out for >10 years. In this paper we present data on registered colonies and censused cats in Rome from 1991 to 2000; the results of the neutering campaign from 1991 to 2000; and a survey, on 103 cat colonies, on the effects of demographic control of urban feral-cat colonies in the city of Rome, carried out by the local Veterinary Public Services (VPS) in collaboration with the associations of cat care-takers. In 10 years almost 8000 were neutered and reintroduced in their original colony. The spay/neuter campaigns brought about a general decrease in cat number but the percentage of cat immigration (due to abandonment and spontaneous arrival) is around 21%. This suggests that all these efforts without an effective education of people to control the reproduction of house cats (as a prevention for abandonment) are a waste of money, time and energy. 相似文献
4.
5.
6.
Robson RV Alves Tatiana Soares Elinaldo FL Bento Ricardo S Roldan‐Filho Brbara SS Souza Marcele KN Lima Jssica S Nascimento Luana CBB Coelho Roberto A S Thmarah A Lima Gabriel GA Gonalves Fbio A Brayner Luiz C Alves Daniela MAF Navarro Thiago H Napoleo Patrícia MG Paiva 《Pest management science》2020,76(2):730-736
7.
Sidney F. Bandeira Roberto S.G. Silva Jaqueline M. Moura 《Journal Of Aquatic Food Product Technology》2017,26(4):447-456
The Whitemouth croaker (Micropogonias furnieri), due to its abundance, is considered one of the most traditional and important species fished in the coastal waters and estuaries of South America. The aim of this work was to produce biopolymeric films of gelatins obtained from skin and bones of Whitemouth croaker. The fish gelatins were characterized through the yield, chemical composition, physiochemical, and rheological properties. The films were characterized by tensile strength (TS), elongation at break (EAB), water vapor permeability (WVP), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and optical properties. The values of protein yield, hydroxyproline content, gel strength, melting temperature, gelling temperature, and viscosity of the skin gelatin were higher than the values of the bone gelatin. The films obtained of skin gelatin showed all properties and thermal analysis superior in relation to the films of bone gelatin; this can be justified by the best physicochemical and rheological characteristics of the skin gelatin. 相似文献
8.
9.
The importance of geographical origin determination is an increasing and pressing requirement for all foods. Honey is one of the largest studied foods due to its nutritional and medicinal properties in a correct diet. In this paper, a total of 41 honey samples (polyfloral and acacia) from different countries have been analyzed in terms of (1)H NMR spectroscopy coupled with multivariate statistical methods. Unsupervised principal component analysis resulted as an efficient tool in distinguishing (1)H NMR spectra of polyfloral and acacia honey samples and for geographical characterization of the latter ones. Hierarchical projection to latent structures discriminant analysis was successfully applied for the discrimination among polyfloral honey samples of different geographical origins. (13)C NMR spectroscopy was applied to honey samples with the aim to investigate possible sugar isoforms differentiation. Our preliminary data indicated a different isoforms ratio between betaFP and betaFF only for polyfloral Argentinean samples, while Hungarian samples showed resonance shifts for some carbons of alphaFF, betaFP, betaFF, and alphaGP isoforms for both varieties. These data confirmed the potentiality of (13)C spectroscopy in food characterization, especially in sugar-based foods. 相似文献
10.
Johansson L Rytkonen A Bergman P Albiger B Källström H Hökfelt T Agerberth B Cattaneo R Jonsson AB 《Science (New York, N.Y.)》2003,301(5631):373-375
The human-specific bacterial pathogen Neisseria meningitidis is a major cause of sepsis and/or meningitis. The pili of N. meningitidis interact with CD46, a human cell-surface protein involved in regulation of complement activation. Transgenic mice expressing human CD46 were susceptible to meningococcal disease, because bacteria crossed the blood-brain barrier in these mice. Development of disease was more efficient with piliated bacteria after intranasal, but not intraperitoneal, challenge of CD46 transgenic mice, suggesting that human CD46 facilitates pilus-dependent interactions at the epithelial mucosa. Hence, the human CD46 transgenic mice model is a potentially useful tool for studying pathogenesis and for vaccine development against meningococcal disease. 相似文献