全文获取类型
收费全文 | 1028篇 |
免费 | 60篇 |
专业分类
林业 | 153篇 |
农学 | 65篇 |
基础科学 | 7篇 |
134篇 | |
综合类 | 123篇 |
农作物 | 31篇 |
水产渔业 | 48篇 |
畜牧兽医 | 463篇 |
园艺 | 15篇 |
植物保护 | 49篇 |
出版年
2021年 | 15篇 |
2020年 | 12篇 |
2019年 | 20篇 |
2018年 | 23篇 |
2017年 | 27篇 |
2016年 | 21篇 |
2015年 | 28篇 |
2014年 | 27篇 |
2013年 | 38篇 |
2012年 | 53篇 |
2011年 | 43篇 |
2010年 | 25篇 |
2009年 | 38篇 |
2008年 | 46篇 |
2007年 | 41篇 |
2006年 | 34篇 |
2005年 | 33篇 |
2004年 | 29篇 |
2003年 | 43篇 |
2002年 | 28篇 |
2001年 | 27篇 |
2000年 | 31篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 10篇 |
1989年 | 21篇 |
1988年 | 19篇 |
1987年 | 11篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1977年 | 14篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1973年 | 6篇 |
1972年 | 9篇 |
1971年 | 8篇 |
1969年 | 8篇 |
1967年 | 8篇 |
1966年 | 14篇 |
1921年 | 9篇 |
排序方式: 共有1088条查询结果,搜索用时 15 毫秒
1.
A Weber 《Tier?rztliche Praxis》1991,19(5):469-473
The significance of sheep and goats in this country in connection with the zoonoses rabies, tick-borne encephalitis, contagious ecthyma, Q-fever, chlamydiosis, brucellosis, campylobacteriosis, echinococcosis and toxoplasmosis is discussed. 相似文献
2.
This article reviews the capabilities of transrectal ultrasonography for determining the distribution of fluid and tissue within stallion accessory sex glands. Emphasis is placed on describing the normal ultrasonographic appearance of the accessory sex glands, excurrent ducts, and pelvic urethra of stallions during rest, after teasing, and after ejaculation and using this information to detect glandular abnormalities. 相似文献
3.
L G Rickard G L Zimmerman E P Hoberg P W Lockwood D W Weber R Miller 《Veterinary parasitology》1989,33(2):125-133
The effectiveness of the morantel sustained release trilaminate (MSRT) in controlling gastrointestinal nematodes through a grazing season was evaluated using 60 yearling beef stocker calves randomly divided into 2 groups of 30 animals each. In April 1985, the calves comprising the treatment group each received an MSRT designed to release morantel tartrate continuously for 90 days while those of the control group remained unmedicated. All animals were weighed and samples of rectal feces were taken at 14-day intervals, beginning on Day 0, until trial termination (Day 168). At trial termination, 10 control and 10 treated calves were necropsied for recovery of gastrointestinal nematodes. Three sets of parasite-na?ve tracer calves were utilized to evaluate the initial, interim and final levels of pasture contamination by nematode larvae. Overall, the use of the MSRT resulted in a 75.5% reduction (P less than 0.001) in output of nematode eggs from the principals, an 81.8% reduction (P less than 0.001) in numbers of gastrointestinal nematodes in principals (at trial termination), and a 96.9% reduction (P less than 0.05) of pasture larval nematode contamination (as indirectly indicated by parasite burdens in tracer calves). The mean weight advantage of treated calves was 16.6 kg per head (P less than 0.001). 相似文献
4.
5.
6.
133 samples of food were investigated for comparison of a recent commercially available 1-2 test (Biocontrol) with a cultural standard method (non-selective pre-enrichment in buffered peptone water, selective enrichment in Rappaport-Vassiliadis-medium and selenite brilliant-green mannitol enrichment broth, inoculation on two selective agars) for presence of Salmonella. The 1-2 test showed in positive results an accuracy ("sensitivity") of 94.7% and in negative results an assurance ("specificity") of 97.9% and is therefore considered suitable for detection of Salmonella contaminated food. 相似文献
7.
100 faeces samples of cattle were investigated in comparison to a recent commercially available Salmonella Rapid Test (OXOID) and a cultural standard method (non-selective enrichment in buffered peptone water, selective enrichment in RAPPAPORT-VASSILIADIS-medium) for presence of Salmonella. The Salmonella Rapid Test showed in positive results an accuracy ("sensitivity") of 94.7% and in negative results an assurance ("specificity") of 97.5% and is therefore suitable for rapid detection (within 2 days) of faeces sample of cattle with Salmonella. 相似文献
8.
Leslie Boerner Kathleen R Nevis Lynn S Hinckley E Scott Weber Salvatore Frasca 《Journal of veterinary diagnostic investigation》2004,16(2):145-149
On June 25, 2002, aquarium veterinarians treated a 5-year-old, male little blue penguin (Eudyptula minor) that was acutely recumbent and dull, with inappetence of 24-hour duration. The penguin died within 10 minutes of presentation despite emergency resuscitation efforts. Gross pathologic findings consisted of pulmonary congestion and intestinal hemorrhage. Histopathologic findings included necrosis of tips of intestinal villi, increased numbers of mononuclear cells in pulmonary interstitium and hepatic sinusoids, and gram-positive bacteria in systemic microvasculature. Transmission electron microscopic examination revealed short gram-positive bacilli located in lumina of glomerular capillaries and in cytoplasm of mononuclear phagocytic cells in the lung and liver. Erysipelothrix rhusiopathiae was recovered from the lung, liver, and intestine by bacteriologic culture. Amplicons from polymerase chain reaction (PCR) tests using Erysipelothrix genus-specific primers and total genomic DNA extracted from formalin-fixed, paraffin-embedded tissue sections of lung and intestine demonstrated 99% nucleotide sequence identity with 16S small-subunit ribosomal DNA of E. rhusiopathiae and E. tonsillarum. The source of infection was speculated to be fish in the diet; however, repeated attempts to detect Erysipelothrix spp. from the mucous layer of food fish using bacteriologic culture and PCR were unsuccessful. This is the first report of erysipelas in a captive aquatic bird. Details of the isolation of E. rhusiopathiae and the application of molecular testing to identify Erysipelothrix DNA in formalin-fixed, paraffin-embedded tissue sections are given. 相似文献
9.
10.
Colour Flow Mapping examination: An useful screening test for the early diagnosis of ductus venosus patency in canine newborns
下载免费PDF全文
![点击此处可从《Reproduction in domestic animals》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Monica Melandri Gabriele Barella Giulio Aiudi Giovanni Michele Lacalandra Salvatore Alonge 《Reproduction in domestic animals》2018,53(5):1130-1135
Ductus venosus (DV) closure plays a key role in hepatic circulation adaptation to postnatal metabolic function, and DV patency might develop a congenital portosystemic shunt (CPSS). The noninvasive Color Flow Mapping (CFM) examination, a validated method to diagnose CPSS in adult dogs, is routinely performed to assess DV closure after birth in humans. This study aimed to describe the feasibility of the ultrasonographic evaluation of the DV after birth and to determine its closure time in healthy Great Dane neonates. Patency of DV in serial Color Flow Mapping (CFM) examinations and bodyweight (BW) were recorded on Days 0‐3‐6‐9 in 24 neonates that were classified as having patent (PDV) or closed ductusvenosus (CDV) basing on CFM signal presence/absence. Since the 3rd day, DV diameter was recorded. Data were analysed by ANOVA (p < 0.05). All dogs resulted healthy 1 year later. The number of PDV and CDV puppies at birth was not different on Day 3 (24 and 0 vs. 22 and 2, PDV and CDV, respectively), whereas it resulted different on Days 6 (24 and 0 vs. 14 and 10) and 9 (24 and 0 vs. 0 and 24); on Day 3, it was different compared to Days 6 and 9; on Day 6, it was different from Day 9. Reduction of DV diameter resulted positively related to neonatal BW growth. The CFM evaluation of DV closure after birth in Great Dane puppies represents a feasible technique. Present results suggest the time of functional closure in normal neonates within 9 days after birth. Thus, CFM examination, as an early screening test for DV patency evaluation, performed 10 days after birth, may identify suspicious dogs at risk that would require further investigations. Further studies are needed to deepen the role of a delayed closure in low bodyweight and preterm puppies. 相似文献