全文获取类型
收费全文 | 495篇 |
免费 | 17篇 |
国内免费 | 11篇 |
专业分类
林业 | 11篇 |
农学 | 14篇 |
基础科学 | 3篇 |
44篇 | |
综合类 | 46篇 |
农作物 | 12篇 |
水产渔业 | 52篇 |
畜牧兽医 | 302篇 |
园艺 | 6篇 |
植物保护 | 33篇 |
出版年
2023年 | 4篇 |
2022年 | 9篇 |
2021年 | 20篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 28篇 |
2014年 | 23篇 |
2013年 | 16篇 |
2012年 | 11篇 |
2011年 | 22篇 |
2010年 | 24篇 |
2009年 | 25篇 |
2008年 | 23篇 |
2007年 | 14篇 |
2006年 | 26篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1985年 | 13篇 |
1984年 | 4篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1976年 | 6篇 |
1974年 | 3篇 |
1965年 | 3篇 |
1963年 | 4篇 |
1959年 | 4篇 |
1958年 | 5篇 |
1957年 | 6篇 |
1956年 | 5篇 |
1954年 | 5篇 |
排序方式: 共有523条查询结果,搜索用时 0 毫秒
521.
CHU-FA TSAI PEI-YU CHEN CHANG-PO CHEN MING-ANNE LEE GUANG-YAW SHIAH & KUO-TIEN LEE 《Fisheries Oceanography》1998,6(4):238-249
Monthly abundance ( CPUE ) of larval anchovy in the coastal waters off south-western Taiwan from 1980 to 1992 (156 months) fluctuated at intervals corresponding to the 4.3- and 2.2-year cycles of the southern oscillation index ( SOI ). Also, CPUE was significantly correlated with sea surface temperature with a time lag of 3 months and nearly significantly to river flow with a time lag of 4 months, which in turn correlated with SOI at lags of 13–14 months (cross-correlation and transfer function analyses). The results suggested the presence of linkage between recruitment of the larvae and ENSO episodes, perhaps through oceanographic and meteorological conditions that affect coastal upwelling and river discharge. The Kuroshio Current, which is the western extension of the North Equatorial Current, may be one of the important mechanisms of ENSO's teleconnections affecting local climate and fisheries in the western Pacific region. 相似文献
522.
Enhancement of Stress Resistance of the Guppy Poecilia reticulata through Feeding with Vitamin C Supplement 总被引:2,自引:0,他引:2
Lian Chuan Lim Philippe Dhert Wei Yen Chew Veerle Dermaux Hans Nelis Patrick Sorgeloos 《Journal of the World Aquaculture Society》2002,33(1):32-40
This study investigated the use of vitamin C supplement in formulated diets and live Artemia juveniles to enhance the stress resistance of the guppy Poecilia reticulata . To evaluate the stress resistance, fish were subjected to osmotic shock in pre-aerated water containing 35 ppt sodium chloride. Ascorbyl acid-polyphosphate and ascorbyl palmitate were used as vitamin C sources for formulated diets and live Artemia juveniles, respectively. Results showed that guppies fed moist formulated diets supplemented with ascorbic acid at 1,000 mg/kg or 2,000 mg/kg diet displayed significantly higher levels of stress resistance than fish fed control formulated diet for 13 d. The stress resistance of fish fed a lower dose (200 mg/kg diet), however, did not differ significantly from that of the control. On the other hand, the stress resistance of guppies fed Artemia juveniles bio-encapsulated with 10% or 20% ascorbyl palmitate did not show significant difference from that of fish fed control Artemia after 20 d. The stress resistance of these three groups of Artemia- fed fish, however, was significantly higher than that of fish fed the control formulated diet. Biochemical analyses showed that raising the ascorbic acid level in feeds resulted in a concomitant increase in the incorporated ascorbic acid level in the whole-body tissue of the guppy. The increased stress resistance of the guppy fed a vitamin C supplemented diet has also been demonstrated in four commercial farms. The potential application of the improved stress resistance in the ornamental fish industry was discussed. 相似文献
523.
LEE C. BURSTINER DVM MEREDITH FAIRES DVM MSc J. SCOTT WEESE DVM DVSc Diplomate ACVIM 《Veterinary surgery : VS》2010,39(2):150-157
Objective— To evaluate the prevalence of, and risk factors for, methicillin‐resistant Staphylococcus aureus (MRSA) colonization in veterinary personnel. Study Design— Cross‐sectional study. Sample Population— Conference attendees (n=341) at the 2008 American College of Veterinary Surgeons Symposium in San Diego California. Methods— Nasal swabs were collected and tested using selective culture for MRSA. Isolates were typed and risk factors were evaluated using questionnaire data. Results— 17.3% of subjects (17% veterinarians and 18% technicians) were MRSA positive. Colonized individuals originated from 5 different countries, predominantly the United States and Canada. Contact with small ruminants in the preceding 30 days (odds ratio [OR] 2.2), living with a person diagnosed with MRSA in the preceding year (OR 19.8) and working in a clinic where there is a specific person in charge of the infection control program (OR 2.2) were associated with colonization using multivariable analysis. Conclusion— The high rate of colonization identified here provides more evidence that MRSA exposure is likely an occupational risk for veterinary personnel. The equal rates in small animal and large animal personnel were surprising and contradict earlier studies indicating greater rates among equine personnel. The association of MRSA and small ruminant contact has not been reported previously. Clinical Relevance— MRSA is an important emerging pathogen in veterinary medicine and is a concern for both patients and veterinary personnel. The high colonization rate indicates the need to understand and control the spread of MRSA in veterinary clinics. 相似文献