全文获取类型
收费全文 | 293篇 |
免费 | 20篇 |
专业分类
林业 | 9篇 |
农学 | 5篇 |
60篇 | |
综合类 | 24篇 |
农作物 | 11篇 |
水产渔业 | 2篇 |
畜牧兽医 | 195篇 |
园艺 | 1篇 |
植物保护 | 6篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 12篇 |
2013年 | 38篇 |
2012年 | 10篇 |
2011年 | 10篇 |
2010年 | 20篇 |
2009年 | 18篇 |
2008年 | 12篇 |
2007年 | 9篇 |
2006年 | 10篇 |
2005年 | 16篇 |
2004年 | 7篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1969年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有313条查询结果,搜索用时 15 毫秒
21.
P Jacquiet M L Dia N M Perié F Jongejan G Uilenberg P C Morel 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1990,43(4):489-490
A fatal case of bovine theileriosis by Theileria annulata is reported from Mauritania in a Friesian cow born in a dairy farm in Nouakchott. The farm was originally established with cattle imported from France. Specific diagnosis was based on piroplasm morphology and on high specific antibody titres in some of the animals. The only tick found in the herd was Hyalomma dromedarii. Four of 49 local zebus sampled at random in the south of the country had high specific antibody titres to T. annulata, while 14 had lower or doubtful titres. The infection therefore appears to be autochthonous. 相似文献
22.
Cadmium (Cd) uptake by white lupin (Lupinus albus) was studied at low Cd concentrations (0.05nM to 5 μM) in hydroponic solution. Ten 12‐day old seedlings were pretreated in 0.5 mM CaCl2 solution in presence and absence of metabolic inhibitors (DCCD, DNP or NaN3). Cadmium solutions were labelled with carrier free 109CdCl2. Cadmium uptake was measured after a 2 h desorption in unlabelled CdCl2 solution. In the absence of any metabolic inhibitor and at 5 [μM Cd, roots absorbed 235.23 μg Cd/g root dry weight. Over the range of lnM to 5 μM Cd, exchangeable Cd represented approximately 5% of the absorbed fraction, and about 25 % of the total absorbed Cd was adsorbed to the root. Cadmium was passively absorbed to about 30% as observed in the presence of the inhibitor (DCCD). Ative absorption which represented 70% of Cd uptake involved H+‐ATPase carriers. Cadmium absorption was reduced to 30 and 20% in presence of lanthanum (La3+) and zinc (Zn2+), respectively which suggested that calcium (Ca), Cd, and Zn use the same carriers. Cadmium uptake in presence of DNP or NaN3 was approximately 4‐ fold that in control. Data showed presomption for an excretion of Cd out of root cells which could be the expression of a detoxification process limiting cell contamination. 相似文献
23.
A 2-year-old Thoroughbred gelding was evaluated for a grade 3 out of 5 unilateral hind limb lameness. Flexion of the right hock and stifle joints (spavin test) exacerbated the lameness. Response to intra-articular and perineural anaesthesia isolated the source of lameness to the tarsocrural area, despite an absence of tarsocrural joint effusion. Routine radiographic examination of the hock did not reveal any significant abnormalities. Skeletal nuclear scintigraphic evaluation revealed a focal region of increased bone activity in the proximal medial trochlear ridge of the talus. Flexed lateromedial radiographic views identified three discrete semicircular lytic lesions at the proximal articular margin of the medial trochlear ridge of the talus. Conservative management of the lesions was associated with a successful return to racing. The location and appearance of the osteochondral lesions of this report have not been previously reported and may be a manifestation of developmental orthopaedic disease and abnormal endochondral ossification. Nuclear scintigraphy and flexed lateromedial radiographic views facilitated identification of the lesions. This radiographic view is recommended when lameness is isolated to the tarsocrural joint and standard radio-graphic projections fail to identify a cause. 相似文献
24.
25.
26.
27.
28.
29.
A.?M.?Vettraino O.?Morel C.?Perlerou C.?Robin S.?Diamandis A.?VanniniEmail author 《European journal of plant pathology / European Foundation for Plant Pathology》2005,111(2):169-180
The Phytophthora complex associated with Castanea sativa Mill. was investigated in five European countries in 35 regions and with respect to various domestication levels. Annual precipitation and length of drought season were the main parameters that regulated the presence of Phytophthora species in the chestnut stands. Seven species of Phytophthora were detected; three of these, P. megasperma, P. cryptogea and P. syringae had not been previously reported on sweet chestnut. P. cinnamomi. P. cambivora and P. citricola were most frequently isolated. P. cinnamomi and P. cambivora were the species significantly associated with declining trees with symptoms of Ink Disease. P. cinnamomirequired distinct ecological conditions compared to the other species. P. cinnamomi was never detected in sites characterized by minimum temperatures below 1.4 °C, maximum temperature above 28 °C, or soil pH below 5.4. The results obtained provide useful information for modeling the probability of Ink Disease, crown decline and associated Phytophthora species in chestnut groves in global climatic change scenarios. 相似文献
30.
Thomas DG Ravindran V Thomas DV Camden BJ Cottam YH Morel PC Cook CJ 《New Zealand veterinary journal》2004,52(2):76-81
AIM: To compare the effects of four stocking densities (5, 10, 15 or 20 birds per m2) on the performance, carcass characteristics and selected welfare indicators of broiler chickens. METHODS: A total of 756 day-old male broiler chicks were assigned as six replicates of 13, 25, 38 and 50 birds per pen, to stocking densities of 2,000, 1,000, 667 and 500 cm2 floor space per bird, respectively. The birds were housed in floor pens in an environmentally controlled room. Normal commercial diets were fed ad libitum and fresh water was freely available throughout the 5-week study period. Liveweights of birds and feed intake were recorded at weekly intervals. Data on carcass parameters and welfare indicators (moisture, gait scores, feather scores, breast and hip lesions, and foot pad and hock burns) were obtained on Day 35. Adrenal glands were removed at slaughter, weighed and examined histologically to determine the total proportion of cortical and medullary tissues. RESULTS: During the study, the birds at the lowest density grew faster (p<0.001-0.01) and consumed more (p<0.001- 0.01) feed than those at the other three stocking densities. The liveweight gains and feed intake of birds reared at densities of 10, 15 and 20 birds per m2 were similar (p=0.11-0.83 and p=0.17-0.57, respectively). Stocking density had no influence on the feed/weight gain, mortality or carcass characteristics. No breast or hip lesions were observed in carcasses from any of the groups. The weight and structure of the adrenal glands were similar across all groups although the staining of medullary tissue of birds was most intense in the highest stocking density group. As stocking density increased, so did moisture and gait score, hock and foot pad burn scores, and the feather score was adversely affected. CONCLUSIONS: The data showed that the relationship between stocking density and productivity traits was not linear in nature, in accordance with other studies. Under the conditions of the current study, the performance, mortality and carcass characteristics of broilers grown at densities of 10, 15 and 20 birds per m2 were similar. There were some welfare implications at high population densities as indicated by adverse effects on litter quality, gait scores and the incidence of hock and foot pad burns. 相似文献