全文获取类型
收费全文 | 501篇 |
免费 | 26篇 |
专业分类
林业 | 14篇 |
农学 | 8篇 |
基础科学 | 2篇 |
51篇 | |
综合类 | 116篇 |
农作物 | 16篇 |
水产渔业 | 26篇 |
畜牧兽医 | 234篇 |
园艺 | 4篇 |
植物保护 | 56篇 |
出版年
2022年 | 3篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 12篇 |
2016年 | 10篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 28篇 |
2012年 | 18篇 |
2011年 | 23篇 |
2010年 | 19篇 |
2009年 | 28篇 |
2008年 | 18篇 |
2007年 | 21篇 |
2006年 | 11篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 15篇 |
2000年 | 6篇 |
1999年 | 14篇 |
1998年 | 19篇 |
1997年 | 10篇 |
1996年 | 15篇 |
1995年 | 12篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1950年 | 2篇 |
1946年 | 2篇 |
1889年 | 1篇 |
排序方式: 共有527条查询结果,搜索用时 15 毫秒
81.
Sarcomas arising in the equine species are rare tumours, and treatment is generally surgical. Radiotherapy has been used in the management of malignancies of large animals; however, conventional external radiotherapy delivery is difficult. Interstitial brachytherapy has been used in the management of human sarcomas with reasonable success, although equine experience is minimal. We report a case of equine haemangiosarcoma treated with brachytherapy demonstrating the feasibility of the procedure and the highly malignant natural history of haemangiosarcoma. An 8‐year‐old American Saddlebred gelding presented for evaluation of a soft tissue mass on the forehead which had been present for at least 6 months. Initial surgical attempts at management were unsuccessful; therefore a radiation oncologist specialising in brachytherapy was consulted. The radiation oncologist and veterinary surgeon performed an interstitial implant of the tumour mass on the rostrum of the horse under general anaesthesia. The procedure was well tolerated by the horse. The tumour demonstrated immediate response and was noted to have completely regressed within 6 weeks of the implant removal. Unfortunately, the horse developed widespread metastatic disease and required euthanasia. At the time of necropsy, no visible tumour was identified at the implant site. Interstitial brachytherapy is feasible in soft tissue sarcomas of the horse; however, supportive demands are great with this procedure and we recommend it only be done at large speciality centres. 相似文献
82.
High-level gentamicin-resistant and vancomycin-resistant Enterococcus faecium isolated from a wound in a dog 总被引:1,自引:1,他引:0
Y. Abbott B. M. Kirby M. Karczmarczyk † B. K. Markey F. C. Leonard S. Fitzgerald ‡ 《The Journal of small animal practice》2009,50(4):194-197
This report describes the first clinical case, in Europe, of a high-level gentamicin-resistant and vancomycin-resistant Enterococcus faecium infection in a dog. The aim of this report is to alert the veterinary profession to high-level gentamicin-resistant and vancomycin-resistant Enterococcus faecium in companion animal patients. Multi-drug resistant strains of this pathogen are the cause of considerable problems in human hospitals and for community healthcare professionals worldwide. The potential for a similar impact within veterinary medicine is discussed. 相似文献
83.
Md Romij Uddin Leonard John Wade Jong Yeong Pyon Md Abdul Mazid 《Journal of Crop Science and Biotechnology》2009,12(1):17-23
An experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh in Old
Brahmaputra Alluvial Flood Plain (AEZ-9) during December 2005 to May 2006 to examine the root growth of different rice cultivars
under various establishment methods. This experiment comprised two sets of treatment (i) three methods of planting viz., dry
direct seeding, wet direct seeding and transplanting, and (ii) six rice cultivars, two inbreds viz., BRRI Dhan 28 and BRRI
Dhan 29, two hybrids, viz., Aalok 6201 and Sonarbangla 1 and two local improved cultivar viz., Habigonj IV and Habigonj VIII.
Cultivars had more remarkable effect on different root parameters i.e. number of roots, root length, root length density,
root biomass, root weight ratio and root shoot ratio of hybrid, inbred and local improved rice cultivars than method of planting.
BRRI Dhan 28 performed the best for most of the parameters. At harvest, BRRI Dhan 29 showed the best rooting behavior among
the cultivars. For both stages hybrid rice cultivars showed intermediate and local improved cultivars performed lower in rooting
behavior. Direct seeding method performed better than transplanting method for most of the root parameters but wet direct
seeding and dry direct seeding methods were identical. Interaction effect between method of planting and cultivar in most
of the root parameters were insignificant. But, BRRI Dhan 28 and BRRI Dhan 29 under wet direct seeding method and Sonarbanngla
1 under transplanting method showed the best rooting performance among the other combinations. 相似文献
84.
85.
R Barretero‐Hernandez JA Vizcarra A Bowen M Galyean 《Reproduction in domestic animals》2010,45(6):983-987
The effect of exogenous administration of lamprey GnRH‐III (IGnRH‐III) on gonadotropin secretion was evaluated in pigs. Six crossbred barrows (82.4 ± 3.5 kg body weight) were assigned randomly to a replicated 3 × 3 Latin square design to evaluate the effect of 0.1, 1.0 or 10.0 μg/kg body weight of exogenous IGnRH‐III on LH and FSH secretion. To facilitate blood collection and infusion of IGnRH‐III, barrows were catheterized in the jugular vein 1 day before initiation of experiments. Blood samples were taken at 10‐min intervals for 6 h, starting 2 h before treatments were applied. Relative concentrations of LH and FSH were calculated by obtaining the ratio of the average concentration of each hormone 2 h after infusion divided by the average concentration during the 2 h before infusion. Relative concentrations of FSH after IGnRH‐III infusion did not influence mean concentration of FSH at any of the doses; yet 10.0 μg/kg body weight had a significant effect on LH secretion (p < 0.01). Relative concentrations of LH averaged 1.2, 1.0 and 3.0 ng/ml (for doses of 0.1, 1.0 and 10.0 μg/kg body weight of IGnRH‐III respectively). Only a dose of 10 μg/kg body weight elicited a significant LH increase that was associated with exogenous IGnRH‐III infusion. We conclude that IGnRH‐III is a weak GnRH agonist and at high doses, IGnRH‐III has the ability to release LH but not FSH in barrows. 相似文献
86.
Renato G Credie Francisco J Teixeira Neto Tatiana H Ferreira Antônio JA Aguiar Fabio C Restitutti José E Corrente 《Veterinary anaesthesia and analgesia》2010,37(3):240-249
ObjectiveTo investigate the effects of methadone on the minimum alveolar concentration of isoflurane (ISOMAC) in dogs.Study designProspective, randomized cross-over experimental study.AnimalsSix adult mongrel dogs, four males and two females, weighing 22.8 ± 6.6 kg.MethodsAnimals were anesthetized with isoflurane and mechanically ventilated on three separate days, at least 1 week apart. Core temperature was maintained between 37.5 and 38.5 °C during ISOMAC determinations. On each study day, ISOMAC was determined using electrical stimulation of the antebrachium (50 V, 50 Hz, 10 mseconds) at 2.5 and 5 hours after intravenous injection of physiological saline (control) or one of two doses of methadone (0.5 or 1.0 mg kg?1).ResultsMean (±SD) ISOMAC in the control treatment was 1.19 ± 0.15% and 1.18 ± 0.15% at 2.5 and 5 hours, respectively. The 1.0 mg kg?1 dose of methadone reduced ISOMAC by 48% (2.5 hours) and by 30% (5 hours), whereas the 0.5 mg kg?1 dose caused smaller reductions in ISOMAC (35% and 15% reductions at 2.5 and 5 hours, respectively). Both doses of methadone decreased heart rate (HR), but the 1.0 mg kg?1 dose was associated with greater negative chronotropic actions (HR 37% lower than control) and mild metabolic acidosis at 2.5 hours. Mean arterial pressure increased in the MET1.0 treatment (13% higher than control) at 2.5 hours.Conclusions and clinical relevanceMethadone reduces ISOMAC in a dose-related fashion and this effect is lessened over time. Although the isoflurane sparing effect of the 0.5 mg kg?1 dose of methadone was smaller in comparison to the 1.0 mg kg?1 dose, the lower dose is recommended for clinical use because it results in less evidence of cardiovascular impairment. 相似文献
87.
Ilya V. Senechkin Leonard S. van Overbeek Hong Ling Er Oscar de Vos Ariena H. C. van Bruggen 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(4):789-802
Collimonas sp. IS343, isolated from an organically-farmed arable soil and characterized as a broad-range oligotrophic bacterium, was shown to degrade chitin and to suppress R. solani mycelium growth under in vitro conditions at high and low carbon availabilities. In contrast to C. fungivorans Ter331, strain IS343 did not respond with an increase in growth rate to higher carbon levels in liquid medium, it reached higher cell numbers in carbon-poor media and it showed better survival in bulk soil. Therefore, it was concluded that strain IS343 cells are better adapted to circumstances of low carbon availability as present in bulk soils than strain Ter331 cells. Further, strain IS343 cells were more suppressive towards R. solani than strain Ter331 cells in vitro. When introduced into soil, strain IS343 cells delayed disease development caused by R. solani AG2-2IIIB in sugar beet plants. These results suggest that strain IS343 cells are able to tentatively suppress R. solani AG2-2IIIB mycelium growth in soil. Potential mechanisms behind the observed suppressive effects can be competition for available nutrients between strain IS343 cells and R. solani mycelium in soil or the production of chitinase as shown for this and other Collimonas species. 相似文献
88.
89.
Leonard P Gianessi 《Pest management science》2013,69(10):1099-1105
Herbicide use is increasingly being adopted around the world. Many developing countries (India, China, Bangladesh) are facing shortages of workers to hand weed fields as millions of people move from rural to urban areas. In these countries, herbicides are far cheaper and more readily available than labor for hand weeding. History shows that in industrializing countries in the past, including the United States, Germany, Japan and South Korea, the same phenomenon has occurred—as workers have left agriculture, herbicides have been adopted. It is inevitable that herbicide use will increase in sub‐Saharan Africa, not only because millions of people are leaving rural areas, creating shortages of hand weeders, but also because of the need to increase crop yields. Hand weeding has never been a very efficient method of weed control—often performed too late and not frequently enough. Uncontrolled weeds have been a major cause of low crop yields in sub‐Saharan Africa for a long time. In many parts of the world, herbicides are being increasingly used to replace tillage in order to improve environmental conditions. In comparison with tillage, herbicide use reduces erosion, fuel use, greenhouse gas emissions and nutrient run‐off and conserves water. © 2013 Society of Chemical Industry 相似文献
90.