全文获取类型
收费全文 | 496篇 |
免费 | 31篇 |
国内免费 | 2篇 |
专业分类
林业 | 31篇 |
农学 | 8篇 |
99篇 | |
综合类 | 36篇 |
农作物 | 42篇 |
水产渔业 | 50篇 |
畜牧兽医 | 214篇 |
园艺 | 9篇 |
植物保护 | 40篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 25篇 |
2020年 | 18篇 |
2019年 | 32篇 |
2018年 | 22篇 |
2017年 | 15篇 |
2016年 | 17篇 |
2015年 | 23篇 |
2014年 | 21篇 |
2013年 | 12篇 |
2012年 | 38篇 |
2011年 | 51篇 |
2010年 | 20篇 |
2009年 | 17篇 |
2008年 | 30篇 |
2007年 | 30篇 |
2006年 | 26篇 |
2005年 | 20篇 |
2004年 | 23篇 |
2003年 | 19篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 15 毫秒
521.
522.
Concentrations of serum amyloid A and plasma fibrinogen in horses undergoing emergency abdominal surgery 下载免费PDF全文
523.
Ruben Avendaño-Herrera Diana Tapia-Cammas Eric Duchaud Rute Irgang 《Journal of fish diseases》2020,43(8):877-888
Chile is currently the second largest producer of farmed salmon worldwide, but Flavobacterium psychrophilum, as one of the most detrimental pathogens, is responsible for major losses during the freshwater culturing step in salmonid fish farms. An antigenic study conducted 10 years ago reported four serological groups using 20 F. psychrophilum Chilean strains. To reduce disease outbreaks and to develop vaccine candidates, antigenic knowledge needs to be regularly updated using a significant number of additional recent F. psychrophilum isolates. The present study aimed at investigating the serological diversity of 118 F. psychrophilum isolates collected between 2006 and 2018 from farmed Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch). The current study supports an expansion of the known antigenic groups in Chile from 4 to 14. However, the use of the slide-agglutination technique for serotyping is costly, is labour-intensive and requires significant technical expertise. Addressing these points, the mPCR-based procedure was a very useful tool for serotyping the collected Chilean F. psychrophilum isolates. This technique revealed the presence of diverse mPCR serotypes (i.e. types 0, 1, 2 and 4). Therefore, mPCR should be employed to select the bacterial strain(s) for vaccine development and to conduct follow-up, selective breeding or epidemiological surveillance in Chilean fish farms. Given the presented findings, changes to Chilean fish-farming practices are vital for ensuring the continued productivity and well-being of farmed salmonids. 相似文献
524.
Accuracy of radiography, nuclear scintigraphy, and histopathology for determining the proximal extent of distal radius osteosarcoma in dogs 总被引:3,自引:0,他引:3
Leibman NF Kuntz CA Steyn PF Fettman MJ Powers BE Withrow SJ Dernell WS 《Veterinary surgery : VS》2001,30(3):240-245
OBJECTIVE--To compare the accuracy of radiography, nuclear scintigraphy, and histopathology for determining the proximal extent of distal radius osteosarcoma in dogs. STUDY DESIGN--Retrospective clinical study. SAMPLE POPULATION--Twenty client-owned dogs taken to Colorado State University with osteosarcoma of the distal radius. METHODS--Medical records of 20 dogs with confirmed osteosarcoma that underwent a limb-salvage procedure were reviewed. Measurements were performed directly from the lateral view of each radius, from both the scintigram and the radiograph, to determine the length of the radius and the distance from the proximal extent of the tumor to the distal radiographic or scintographic extent of the radius. The ratio of distal radial involvement to total radius length was calculated. A similar ratio was also determined using the macroslide, which included the entire portion of bone that was excised during the limb-salvage procedure. All 3 methods of measurement were compared. RESULTS--Nuclear scintigraphy significantly overestimated tumor length when compared with macroslide specimen measurements. Radiography also overestimated tumor length, but these results were not significantly different from macroslide specimen measurements. CONCLUSIONS--Both radiography and nuclear scintigraphy overestimate the extent of distal radius osteosarcoma in dogs when compared with histopathologic macroslides of the same lesions. Nuclear scintigraphy overestimated tumor extent to a larger degree than did radiography. CLINICAL RELEVANCE--Although radiography is a more accurate method of measurement of the extent of distal radius osteosarcoma, because nuclear scintigraphy overestimates tumor length to a greater degree, scintigraphy may provide a larger margin of safety for determining the site of proximal osteotomy during a limb-salvage procedure. However, caution should be taken when utilizing scintigraphy, because this method may overestimate length of radius involved to such an extent as to cause the surgeon to believe that a patient is not a suitable limb-salvage candidate. 相似文献
525.
In order to assess the effects of different cropping systems on the bacterial flora, we stored 34 batches of carrots of defined origin for extended periods at 5°C and high relative humidity and characterised the pattern of the bacterial flora by using DNA-based fingerprint methods. Four of these batches were spoiled by fungi. Of these, two were from a field experiment where organically grown carrots received additional organic nitrogen. Other effects of the cropping method (organic vs. conventional) were not observed. The “fingerprint methods” SSCP and ARDRA detect differences in the ribosomal RNA. Using them, we found differences in the composition of the bacterial flora of carrots of different origin, and detected shifts of this flora during storage. No clear correlations with the cropping method were found. T-RFLP (a method based on the ARDRA principle) showed differences in the bacterial flora of visibly spoiled carrots. 相似文献
526.
Suarez Victor H. Micheloud Juan F. Araoz Virginia Martínez Gabriela M. Rosa Diana E. Mattioli Guillermo A. 《Tropical animal health and production》2019,51(3):613-618
Tropical Animal Health and Production - The aim of this work was to study the effect of gastrointestinal nematodes (GINs) on copper (Cu) and phosphorus (P) in blood of beef cattle in two ranches... 相似文献
527.
528.
Jess R. Anderson Cody B. Scott Charles A. Taylor Corey J. Owens James R. Jackson Diana K. Steele Richard Brantley 《Strength and Conditioning Journal》2013,66(2):204-208
In the southwestern United States, redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus ashei Buchholz) juniper are two invasive species that dominate some rangelands. Goats will consume up to 30% of their diet in juniper, but it is unknown if sheep will accept juniper to the same extent. The objectives of this study were to determine if sheep can be conditioned to consume juniper and to compare intake among different breeds. Rambouillet (n = 10), Suffolk (n = 10), and Dorper-cross (n = 10) lambs were randomly placed in individual pens for 31 d. A basal diet of alfalfa pellets (2.5% body weight [BW]) and juniper were fed. Juniper was fed each morning from 0800 to 0830 hours. The basal diet was fed for the remainder of the day. Intake of each was measured daily. Following the first 17 d, the basal diet was reduced to 2% BW for 7 d and then reduced to 1.5% BW for the final 7 d. Serum aspartate transaminase (AST), gamma glutamyltransferase (GGT), blood urea nitrogen (BUN), creatinine, and bilirubin levels, and live body weight were measured to assess any adverse physiological effects from juniper consumption. In a second trial, lambs were again fed alfalfa (2.5% BW) and juniper. One half of the lambs were also fed a 36% protein supplement to determine if supplementation with protein sources that escape rumen degradation would improve juniper consumption. Lambs received alfalfa, juniper, and protein supplement for 22 d with intake of each recorded daily. Intake of juniper was similar (P > 0.05) among breeds of sheep. Lambs readily consumed juniper and increased (P < 0.05) intake of juniper as the amount of alfalfa fed was reduced. Weight change was also similar among treatments. Protein supplementation did not improve juniper consumption. We contend that sheep will consume a diet consisting of 24% juniper without experiencing any adverse effects. 相似文献
529.
Assessment of Left Atrial Deformation and Function by 2‐Dimensional Speckle Tracking Echocardiography in Healthy Dogs and Dogs With Myxomatous Mitral Valve Disease 下载免费PDF全文