全文获取类型
收费全文 | 1017篇 |
免费 | 57篇 |
国内免费 | 1篇 |
专业分类
林业 | 29篇 |
农学 | 44篇 |
基础科学 | 3篇 |
100篇 | |
综合类 | 261篇 |
农作物 | 117篇 |
水产渔业 | 87篇 |
畜牧兽医 | 381篇 |
园艺 | 11篇 |
植物保护 | 42篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 30篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 20篇 |
2017年 | 13篇 |
2016年 | 25篇 |
2015年 | 19篇 |
2014年 | 26篇 |
2013年 | 47篇 |
2012年 | 68篇 |
2011年 | 72篇 |
2010年 | 40篇 |
2009年 | 41篇 |
2008年 | 83篇 |
2007年 | 87篇 |
2006年 | 85篇 |
2005年 | 70篇 |
2004年 | 49篇 |
2003年 | 46篇 |
2002年 | 48篇 |
2001年 | 38篇 |
2000年 | 26篇 |
1999年 | 13篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有1075条查询结果,搜索用时 156 毫秒
101.
102.
K.‐C. Cho Y.‐J. Han S.‐J. Kim S.‐S. Lee O.‐J. Hwang P.‐S. Song Y.‐S. Kim J.‐I. Kim 《Plant pathology》2011,60(4):631-639
A pepper esterase (PepEST) gene was introduced into creeping bentgrass (Agrostis stolonifera) by Agrobacterium‐mediated transformation. Purified recombinant PepEST proteins were sufficient to inhibit the growth of the fungal pathogens Rhizoctonia solani AG2‐2 (IIIB) (causing brown patch) and Sclerotinia homoeocarpa (dollar spot), but not the oomycete responsible for pythium blight, Pythium aphanidermatum. PepEST proteins were most effective against R. solani. After genetic transformation of creeping bentgrass with PepEST, the genomic integration of transgenes bar and PepEST was confirmed by Southern blot analysis, and their expression was also validated by northern blot and western blot analyses. Disease severity on R. solani‐inoculated leaves of transgenic plants was <10% compared to ca. 50% in non‐transgenic plants. Microscopic observation of infected leaves indicated that PepEST inhibited the growth of hyphae upon fungal infection. 相似文献
103.
Lyons MM Yu C Toma RB Cho SY Reiboldt W Lee J van Breemen RB 《Journal of agricultural and food chemistry》2003,51(20):5867-5870
Resveratrol in the fruits of bilberry (Vaccinium myrtillus L.), the lowbush "wild" blueberry (Vaccinium angustifolium Aiton), the rabbiteye blueberry (Vaccinium ashei Reade), and the highbush blueberry (Vaccinium corymbosum L.) were measured using a new assay based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS assay provided lower limits of detection than previous methods for resveratrol measurement, 90 fmol of trans-resveratrol injected on-column, and a linear standard curve spanning >3 orders of magnitude. The recoveries of resveratrol from blueberries spiked with 1.8, 3.6, or 36 ng/g were 91.5 +/- 4.5, 95.6 +/- 6.5, and 88.0 +/- 3.6%, respectively. trans-Resveratrol but not cis-resveratrol was detected in both blueberry and bilberry samples. The highest levels of trans-resvertatrol in these specimens were 140.0 +/- 29.9 pmol/g in highbush blueberries from Michigan and 71.0 +/- 15.0 pmol/g in bilberries from Poland. However, considerable regional variation was observed; highbush blueberries from British Columbia contained no detectable resveratrol. Because blueberries and bilberries are often consumed after cooking, the effect of baking on resveratrol content was investigated. After 18 min of heating at 190 degrees C, between 17 and 46% of the resveratrol had degraded in the various Vaccinium species. Therefore, the resveratrol content of baked or heat-processed blueberries or bilberries should be expected to be lower than in the raw fruit. Although blueberries and bilberries were found to contain resveratrol, the level of this chemoprotective compound in these fruits was <10% that reported for grapes. Furthermore, cooking or heat processing of these berries will contribute to the degradation of resveratrol. 相似文献
104.
Therapeutic effect of hyaluronic acid on experimental osteoarthrosis of ovine temporomandibular joint. 总被引:3,自引:0,他引:3
C H Kim B J Lee J Yoon K M Seo J H Park J W Lee E S Cho J J Hong Y S Lee J H Park 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(10):1083-1089
A symptomatic relief by hyaluronic acid (HA, MW: 3.5 x 10(6)), which is synthesized by Streptococcus spp, was investigated in experimental ovine osteoarthrosis. Bilateral osteoarthrosis (OA) of the temporo-mandibular joints (TMJs) was induced by perforating discs and by scrapping subchondral condylar surface. HA was intra-articularly injected into the left joints of 6 sheep on 7, 10, 14, 17 and 21 days after the operation and physiological saline as the control was injected into the contralateral (right) joints on the same day. Three sheep were killed at I month post-operation (MPO) and the remaining three sheep were killed at 3 MPO. Various responses such as proliferation of fibrous tissue, denudation, erosion, osteophyte formation, subcortical cyst formation and ankylosis were observed radiographically and histopathologically. The treatment of HA ameliorated the degenerative changes and lowered the osteoarthrotic score in the left joints at I MPO (9.96 vs 5.81) and 3 MPO (10.86 vs 5.29) compared to the right joints. These results indicate that a repeated intra-articular injection of HA inhibits the progression of OA in ovine TMJs by inducing the development of articular cartilage and by reducing the proliferation of fibrotic tissue. 相似文献
105.
A survey of the aerobic bacteria in the feces of captive raptors 总被引:5,自引:0,他引:5
Feces of 47 captive raptors belonging to the order Falconiformes or Strigiformes were cultured for bacteria. Gram-negative bacteria, which were cultured from the feces of 45 of the 47 raptors, were the most common isolates. A wide variety of species were identified, including a newly described genus (Moellerella wisconsensis), two newly described species (Escherichia fergusonii and Proteus penneri), and a member of a newly described enteric group (CDC Enteric group 41). Additional organisms identified that have not been reported in previous bacteriological surveys of raptors were Salmonella heidelberg, Salmonella braenderup, Morganella morganii, Yersinia ruckeri, Serratia spp., and Kluyvera sp. Escherichia coli, isolated from the feces of 42 of the 47 raptors, was the most frequently recovered. Streptococcus faecalis, the second most common isolate, was cultured from 30 birds. Several differences were observed between fecal bacteria isolated from raptors fed commercially prepared chicken and those isolated from raptors not fed chicken. The most obvious difference was that birds fed chicken had more varied gram-negative bacterial species and in greater numbers per fecal sample. The potential for the isolated bacteria from raptors as pathogens in humans and avian species is discussed. 相似文献
106.
D Y Cho R A Frey M M Guffy H W Leipold 《American journal of veterinary research》1975,36(11):1597-1603
Toxic effects of excessive vitamin A and of excessive vitamin ADE were studied in 9 mixed Labrador Retriever pups. Clinical signs were loss of body weight, dullness, emaciation, roughened coat, evident pain in limb joints, and retarded growth. Radiologic changes were decreases in overall length and thickness of long bones, development of osteophytes, periosteal reaction, and premature closure of epiphyses. Pathologic changes were degenerative epiphyseal plate, hemorrhage and exostotic proliferation of periosteum, fatty liver, and microcalculi in kidney. Toxic effects of excessive vitamin A did not appear to be so great when it was administered as vitamin ADE. 相似文献
107.
The effects of passive immunization with immunoglobulin Y (IgY) on the pathogenesis of Marek's disease (MD) were examined in an experimental line of White Leghorn chickens highly susceptible to MD. Purified IgY with anti-MDV antibody activity, when injected into chicks, delayed the development of MDV viremia and lesions until 9 days postinoculation (PI) with Marek's disease virus (MDV). The blastogenic response of spleen cells to concanavallin-A was depressed at 6 days PI in the birds without passive immunization, whereas it was not totally depressed until 17 days in birds passively immunized with IgY anti-MDV antibody. 相似文献
108.
Phosphorus and ammonium nitrogen placed together has been shown to increase P uptake by crops, especially cereals, Thus, the objective of this study was to compare this effect on four crops grown in Manitoba. Plants harvested at flowering indicated greater P uptake in lentils, soybean and wheat, when P and NH4 + -N were placed on the same band. In contrast, canola did not respond to this treatment. Possible relationships of these ions are presented. 相似文献
109.
Five kittens exposed neonatally to older cats exhibiting fever with nasal and ocular discharge became ill and died within 10 days of the onset of illness. One kitten which died at 16 days old was examined post mortem and feline herpesvirus 1 was isolated from the brain, liver, lung and spleen. 相似文献
110.