全文获取类型
收费全文 | 166篇 |
免费 | 10篇 |
专业分类
林业 | 14篇 |
农学 | 7篇 |
35篇 | |
综合类 | 18篇 |
农作物 | 10篇 |
水产渔业 | 12篇 |
畜牧兽医 | 61篇 |
园艺 | 2篇 |
植物保护 | 17篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 18篇 |
2011年 | 19篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1987年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1955年 | 1篇 |
1950年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有176条查询结果,搜索用时 15 毫秒
121.
Prullage JB Tran HV Timmons P Harriman J Chester ST Powell K 《Veterinary parasitology》2011,179(4):302-310
The motility of adult Rhipicephalus sanguineus was evaluated subsequent to treatments of amitraz, fipronil and the combination of fipronil plus amitraz against a vehicle control in a Petri dish assay using the LemnaTec Scanalyzer Imaging System. The assay was run using a fixed dilution of amitraz (0.32μg/cm(2)); serial dilutions of fipronil (1.3, 0.33, 0.08, 0.02, or 0.005μg/cm(2)); and the same serial dilutions of fipronil in combination with the fixed dilution of amitraz. Measurement of motility was made of unstimulated ticks and then after stimulation at 1, 4, 18-22, and 24h post exposure (hpe) of the Petri dishes. For the unstimulated ticks, there was no difference in motility between the amitraz treatment group and the fipronil plus amitraz treatment group at the early time points. However, these two treatment groups had significantly higher motility than the solvent control and fipronil treatment groups. The unstimulated ticks in the amitraz treatment group had significantly higher motility than the fipronil plus amitraz treatment group at the later time points. Measurements after stimulation demonstrated there was no difference in motility between the amitraz treatment group and the fipronil plus amitraz treatment group at the early time points. By 18 hpe, the fipronil plus amitraz treatment group had significantly lower motility than all other treatment groups and at 21-22 and 24 hpe the other treatment groups did not differ from the control group. The action could be divided in two phases in the combination experiment: phase 1: an early increase in motility due to amitraz is identified in both amitraz alone or fipronil plus amitraz groups; phase 2: the combination of fipronil plus amitraz caused a significantly greater reduction in motility, suggesting mortality of the ticks, compared to fipronil or amitraz alone. These results demonstrate a synergism resulting from the combination of fipronil plus amitraz. 相似文献
122.
Sung Phil Mun M. Sarwar Jahan A. Al-Maruf D. A. Nasima Chowdhury 《Wood Science and Technology》2011,45(2):281-288
Lack of data especially pertaining to the chemistry of mangrove wood species makes it difficult to prepare successful plans
for their conservation and to use mangroves as a source of wood fiber. In this paper, chemical characterizations of the six
main mangrove species of Bangladesh [namely Keora (Sonneratia apetala), Geoa (Excoecaria agallocha), Bine (Avicennia alba), Sundari (Heritiera fomes) Pashur (Xyloccarpous mekongests), and Kakra (Bruguiera gymnorhiza)] were investigated. The chemical results revealed that these species contain high percentages of dichloromethane followed
by methanol extractives. Methanol extracts in Pashur, Sundari, and Bine were higher than 10%, which indicates high percentage
of tannin material. The total lignin content in these species was higher than 25%, except for Gewa (23.6%) and Pashur (21.3%),
which is higher than that of the normal range of hardwood. The pentosan content in these six species was within the range
of 19.4–22.8%. The α-cellulose content in Keora and Gewa was acceptable for pulp production, but the others were lower than
the normal range of hardwood. Alkaline nitrobenzene oxidation showed that all these species had a very high syringaldehyde
to vanillin (2.6–5.0) ratio except Keora (1.6). Surprisingly, rhamnose is the main constituent with xylose of hemicelluloses
of these six mangrove species. The ash content in these six mangrove wood species was also higher than that in normal hardwood. 相似文献
123.
Hayley C. Norman Alan W. Humphries Elizabeth Hulm Paul Young Steve J. Hughes Trevor Rowe David M. Peck Phil E. Vercoe 《Grass and Forage Science》2021,76(1):134-158
In the rain‐fed mixed‐farming systems of southern Australia, the consistent supply of high‐value forage is limited by a range of climatic, edaphic and systems constraints. Over 2 years, we compared biomass production and nutritional value of 30 accessions of perennial legumes, and predicted intake, grazing days and growth of ewes and lambs. There was significant variation in nutritional value and biomass production between and within species. Lucerne (Medicago sativa) and sulla (Hedysarum coronarium) produced the greatest amount of biomass and energy. There was variability among accessions in digestibility (DMD), acid detergent fibre (ADF) and crude protein, and the rate of change in these traits as plants matured. Trifolium species had the highest DMD across all growth stages. Hairy canary clover (Dorycnium hirsutum), erect canary clover (Dorycnium rectum), greater birdsfoot trefoil (Lotus uliginosus), Australian trefoil (Lotus australis) and running postman (Kennedia prostrata) had energy levels that would not maintain liveweight of mature sheep. In the second year, species differed in response to harvesting treatments. Lucerne and sainfoin (Onobrychis viciifolia) were more productive under a frequent cutting regime. Accessions of white clover (Trifolium repens), red clover (Trifolium pratense), alsike clover (Trifolium hybridum), cullen (Cullen australasicum), strawberry clover (Trifolium fragiferum), sainfoin and birdsfoot trefoil (Lotus corniculatus) showed some promise, while Tedera (Bituminaria bituminosa) and milkvetch (Astragalus cicer) performed poorly under the experimental conditions. We conclude by discussing additional agronomic and nutritional factors that need consideration when developing novel perennial legumes for mixed‐farming systems in the context of a changing climate. 相似文献
124.
F.N. Fastier D.Sc. D.Phil. F.R.I.C. 《New Zealand veterinary journal》2013,61(8):148-151
Extract No doubt you would all be delighted to note when Mr MacIntyre opened this conference that our Minister of Lands is well aware of the economic loss resulting from disease in animals. He estimated the national loss for 1969 to be between $110 and $130 million. Now, about 5% of this loss can be attributed to hydatid disease. We should be thankful that man is a less attractive secondary host for Echinococcus granulosus than is the sheep, because hydatids is a horrible disease which can still be fatal. It affects some lives as well as many purses. Moreover, hydatid disease is very much our problem in that most of the countries that have better facilities for re-search in this field have little incentive for entering it. 相似文献
125.
126.
127.
Melissa Smith Jonathon R. Dodd H. Phil Hobson Sharman Hoppes 《Journal of Exotic Pet Medicine》2013,22(3):258-264
Acquired dental disease and the formation of elodontomas are often diagnosed in sciurids. The formation of the elodontoma may be preceded by a traumatic tooth injury or other initiating factors. The degree of disease severity varies based on individual presentation and the time of detection. Maxillary elodontomas in sciurid species cause airway obstruction that can prove fatal for these obligate nasal-breathing animals. A thorough understanding of rodent dental anatomy and a complete diagnostic workup are required for diagnosis, prognosis, and surgical planning of elodontoma presentations. This article highlights 2 successful surgical techniques for the removal of the maxillary incisors in sciurid patients with almost total occlusion of the nasal passage. 相似文献
128.
Biochemical markers of cardiac injury in normal, surviving septic, or nonsurviving septic neonatal foals 总被引:6,自引:0,他引:6
Slack JA McGuirk SM Erb HN Lien L Coombs D Semrad SD Riseberg A Marques F Darien B Fallon L Burns P Murakami MA Apple FS Peek SF 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(4):577-580
The cardiac biomarkers cardiac troponin T (cTnT) and I (cTnI) and the cardiac isoenzyme of creatine kinase (CKMB) are used extensively in human medicine to diagnose and provide valuable prognostic information in patients with ischemic, traumatic, and septic myocardial injury. We designed a study to establish normal values for these markers in healthy, neonatal foals and to compare them with values obtained from septic neonates in a referral hospital population. The 25th, 50th, 75th, and 95th percentiles for cTnI and CKMB in the healthy-foal population were 0.08, 0.14, 0.25, 0.49 ng/mL and 1.4, 2.3, 4.0, 7.4 ng/mL, respectively. The values obtained for cTnT were frequently (43/52 foals; 83%) below the lower limit of detection of the assay (0.009 ng/mL), but the median and range were 0.009 and 0.009-0.041 ng/mL, respectively. In the septic foal population, the 25th, 50th, 75th, and 95th percentile values for cTnI and CKMB were 0.05, 0.12, 0.22, and 1.10 ng/mL and 2.0, 4.4, 7.8, and 24 ng/mL, respectively. The values obtained for cTnT were less frequently below the lower limit of detection (23/38 foals; 60%) compared with the healthy foal population, and the median and range were 0.009 and 0.009-0.20 ng/mL, respectively. Significantly higher values were observed for cTnT and CKMB in septic foals compared with the healthy neonatal foal population, but there were no differences among septic foals in survivors compared with nonsurvivors. These findings suggest that myocardial injury occurs during septicemia in neonatal foals but that the injury is not associated with survival among septic foals. 相似文献
129.
130.