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排序方式: 共有203条查询结果,搜索用时 15 毫秒
51.
感染E.tenella对肉仔鸡生长、营养物质表观存留率及血液生理指标的影响 总被引:1,自引:0,他引:1
为了研究玉米 -豆粕型基础饲养下感染球虫对肉仔鸡生长、营养物质表观存留率、血液生理指标的影响 ,用 48只 1周龄 ( AA)肉仔鸡进行试验 ,按体重随机分为 2组 ,代谢期 1周。试验组鸡 1 4日龄时分别感染柔嫩艾美耳球虫卵囊 9万个 /只。结果表明 :试验组除饲料转化比 ,在代谢期后 4天间有显著差异外 ,其余多数生长性能指标在两组间无显著差异 ( P>0 .1 )。但感染球虫降低了试验组鸡的营养物质的表观存留率 相似文献
52.
Lindenberg AM Larsson J Sokolowski-Tinten K Gaffney KJ Blome C Synnergren O Sheppard J Caleman C Macphee AG Weinstein D Lowney DP Allison TK Matthews T Falcone RW Cavalieri AL Fritz DM Lee SH Bucksbaum PH Reis DA Rudati J Fuoss PH Kao CC Siddons DP Pahl R Als-Nielsen J Duesterer S Ischebeck R Schlarb H Schulte-Schrepping H Tschentscher T Schneider J von der Linde D Hignette O Sette F Chapman HN Lee RW Hansen TN Techert S Wark JS Bergh M Huldt G van der Spoel D Timneanu N Hajdu J Akre RA Bong E 《Science (New York, N.Y.)》2005,308(5720):392-395
The motion of atoms on interatomic potential energy surfaces is fundamental to the dynamics of liquids and solids. An accelerator-based source of femtosecond x-ray pulses allowed us to follow directly atomic displacements on an optically modified energy landscape, leading eventually to the transition from crystalline solid to disordered liquid. We show that, to first order in time, the dynamics are inertial, and we place constraints on the shape and curvature of the transition-state potential energy surface. Our measurements point toward analogies between this nonequilibrium phase transition and the short-time dynamics intrinsic to equilibrium liquids. 相似文献
53.
By employing cells mutating at a very high spontaneous rate and a grid plate containing a medium totally selective against mutant cells, direct microscopic observation was made of mutant cells of recent origin passing through a limited number of phenomic lag divisions. 相似文献
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55.
J C Burnett P C Kao D C Hu D W Heser D Heublein J P Granger T J Opgenorth G S Reeder 《Science (New York, N.Y.)》1986,231(4742):1145-1147
A sensitive radioimmunoassay for atrial natriuretic peptide was used to examine the relation between circulating atrial natriuretic peptide and cardiac filling pressure in normal human subjects, in patients with cardiovascular disease and normal cardiac filling pressure, and in patients with cardiovascular disease and elevated cardiac filling pressure with and without congestive heart failure. The present studies establish a normal range for atrial natriuretic peptide in normal human subjects. These studies also establish that elevated cardiac filling pressure is associated with increased circulating concentrations of atrial natriuretic peptide and that congestive heart failure is not characterized by a deficiency in atrial natriuretic peptide, but with its elevation. 相似文献
56.
Tee KY Kao JP Chiu HY Chang MH Wang JH Tung KC Cheng FP Wu JT 《Veterinary parasitology》2011,183(1-2):68-71
Encephalitozoon cuniculi (E. cuniculi) is a microsporidian parasite commonly found in rabbits that can infect humans, causing encephalitozoonosis. Our laboratory recently confirmed the first case of encephalitozoonosis in a rabbit in Taiwan; the prevalence of encephalitozoonosis is not well documented, even when many clinics suspect pet rabbits as being infected. This study surveys the seropositivity of E. cuniculi using carbon immunoassay (CIA) and enzyme-linked immunosorbent assay (ELISA). Serological examination of 171 rabbits using CIA and ELISA showed that 63.2% (108/171) and 67.8% (116/171) were seropositive against E. cuniculi, respectively. Thirteen of the 14 rabbits (92.9%) with neurological symptoms were seropositive. Except for gender, health status and location had a significant effect on E. cuniculi seropositivity (p<0.05). Adult rabbits aged older than 4 months exhibited significantly higher seropositivity for E. cuniculi than young rabbits (p<0.05). In conclusion, this study shows that E. cuniculi is present and widespread among healthy rabbits in Taiwan. Therefore, the fields of veterinary and human medicine in Taiwan should be aware of this zoonotic issue and the resulting public health concern of encephalitozoonosis. 相似文献
57.
The objectives of this study were first to show adrenocortical response to a long‐acting adrenocorticotropic hormone preparation (tetracosactide acetate zinc suspension) (ACTH‐Z) and its effect on adrenocortical function in beef cows ( Experiment 1 ) and second to apply the ACTH‐Z challenge in dairy cows based on cortisol concentrations in milk collected at routine milking ( Experiment 2 ). In Experiment 1 , four beef cows in luteal phase were challenged with ACTH‐Z, and plasma cortisol concentrations were determined for 48 h after the injection at 30‐min to 2‐h intervals. A rapid ACTH test was conducted 3 days before and 2 h after the completion of ACTH‐Z injection for 48 h to investigate the effect on adrenocortical function. Plasma cortisol concentrations increased significantly 30 min after ACTH‐Z injection (p < 0.001), and the high cortisol levels were maintained for approximately 10 h after the injection. In Experiment 2 , eight dairy cows were subjected to ACTH‐Z challenge 1–2 weeks and 4–5 weeks post‐partum. Blood and milk samples were taken at morning and afternoon milking. All the cows showed a significant increase in cortisol concentrations in plasma as well as in skim milk 8 h after ACTH‐Z injection 1–2 weeks and 4–5 weeks post‐partum (p < 0.001). There was a significant correlation between plasma and skim milk cortisol concentrations 8 h after ACTH‐Z challenge (r = 0.74, p < 0.001). The results obtained in this study suggest that elevated levels of plasma cortisol are maintained for approximately 10 h after ACTH‐Z treatment without adverse effect on adrenocortical function and a long‐acting ACTH‐Z challenge based on cortisol concentrations in milk, which were collected at the morning and the afternoon milking, can be a useful tool to monitor adrenocortical function in cows. 相似文献
58.
The objective of this study was to show plasma cortisol concentration after treatment with controlled internal drug release (CIDR) in non‐suckling beef cows. On day 9 after oestrus, two cows were inserted with CIDR into the vagina for 24 h and the other two cows were treated as a control group. Four days later, the two control cows were treated with CIDR and the other two CIDR‐treated cows were used as controls. Cortisol concentrations were determined by ELISA in plasma samples collected before, during and after insertion of CIDR. There was a significant increase in plasma cortisol concentrations (p < 0.01) after insertion of CIDR. Mean (±SEM) plasma cortisol concentrations increased from 1.3 ± 0.4 to a peak of 8.8 ± 1.1 ng/ml at 5 h and then decreased to basal concentrations at 7 h after insertion of the device. In conclusion, the insertion of intra‐vaginal device causes an increase in plasma cortisol concentrations in beef cows, although the pathophysiological significance of the elevation of cortisol is not known. 相似文献
59.
The Cattle Tracing System (cts) of Great Britain was examined to investigate the quality of its data in terms of known errors and omissions, and their distribution. The proportions of erroneous or missing data have decreased steadily over time, with a marked improvement in the quality of the data since 2001, when recording became mandatory. There is little variation between regions in the quality of the data, but there are potentially important variations between the types of agricultural premises that cattle move to and from, and in other factors correlated with the type of premises, such as the age of the animals and the number of animal movements associated with the premises. 相似文献
60.