全文获取类型
收费全文 | 214篇 |
免费 | 8篇 |
专业分类
林业 | 21篇 |
农学 | 7篇 |
基础科学 | 2篇 |
27篇 | |
综合类 | 8篇 |
农作物 | 14篇 |
水产渔业 | 22篇 |
畜牧兽医 | 113篇 |
园艺 | 3篇 |
植物保护 | 5篇 |
出版年
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 3篇 |
2015年 | 15篇 |
2014年 | 7篇 |
2013年 | 13篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 15篇 |
2008年 | 8篇 |
2007年 | 18篇 |
2006年 | 11篇 |
2005年 | 22篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1985年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有222条查询结果,搜索用时 855 毫秒
111.
The behaviors of cellulose (commercially available filter paper) were investigated in glow-discharge plasma, where pyrolysis does not occur because of low temperatures. Cellulose filter papers were decomposed in a glow-discharge plasma with nitrogen flow even at low temperatures of around 50 °C and disappeared completely after a treatment of approximately 90 h without char formation. Tar formation was not observed on any surfaces inside the plasma chamber and vacuum lines. Hence, it was concluded that all cellulose was decomposed into gaseous products. An in-situ analysis of gaseous products by quadrupole mass spectrometry suggested the formation of H2, H2O, CO and CO2 from cellulose. These findings indicate that a clean and complete gasification of cellulose can be achieved with glow-discharge plasma. 相似文献
112.
113.
114.
CCC treatment at flowering time suppressed the occurrence of tomato fruit puffiness in solution culture. Root application, truss spraying and whole plant spraying of CCC were all effective in correcting fruit puffiness, and truss spraying did not decrease fruit weight, unlike the other two treatments. For practical use, truss spraying might be the best method to control tomato fruit puffiness.Cytokinin contents in the xylem sap of tomatoes increased when CCC was applied to roots. This suggests that cytokinin biosynthesis in roots was increased by CCC treatment. Cytokinin activities in tomato fruits at an early developmental stage were also markedly increased by CCC treatment to roots. These results suggest that the CCC effect on the control of tomato fruit puffiness might be partly due to increased cytokinin activity in the developing fruit. 相似文献
115.
Protective effect of Clostridium septicum alpha-toxoid vaccine against challenge with spores in guinea pigs 总被引:4,自引:0,他引:4
Amimoto K Ohgitani T Sasaki O Oishi E Katayama S Isogai M Ota S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(1):67-69
The protective effect of an alpha-toxoid vaccine of Clostridium septicum purified alpha-toxin was investigated in guinea pigs. Purified alpha-toxin was treated with formalin to make toxoid, and alpha-toxoid vaccine was prepared by mixing alpha-toxoid (4 to 64 microg/dose) with an aluminum phosphate gel as adjuvant. Guinea pigs were immunized twice with different doses of alpha-toxoid vaccine, and challenged with spores of C. septicum. The guinea pigs surviving after challenge had been immunized with 8 microg/dose or more of alpha-toxoid. All these animals produced titers of 20 units or higher of antitoxin at the challenge. The results suggest that C. septicum alpha-toxin plays an important role in protection against challenge with spores in guinea pigs. 相似文献
116.
Inokuma H Fujimoto T Hosoi E Tanaka S Fujisaki K Okuda M Onishi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(7):615-617
Ticks were collected from 94 sika deer (Cervus nippon) hunted in the western part of Yamaguchi Prefecture, Japan from August to November 1999, and March to July 2000. Haemaphysalis longicornis and H. yeni were the dominant species from April to August, while H. flava and H. megaspinosa were dominant in October, November and March. This is the first report of H. yeni in the mainland of Japan. Small numbers of H. kitaokai, Amblyomma testudinarium and Ixodes ovatus were also recorded. 相似文献
117.
Onuma M Suzuki M Uchida E Niiyama M Ohtaishi N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):309-313
Fecal estradiol concentrations were measured in three captive unmated female sun bears (Helarctos malayanus) from August 1998 to July 1999 in Sarawak, Malaysia and vaginal smears from one of the females was observed in August 1998 and March 1999. A single peak in fecal estradiol concentration was obvious for each bear in August or September 1998, and there was a much higher percentage of superficial vaginal anuclear cells in August 1998 than in March 1999. These results suggest that sun bears in Sarawak are likely to be a seasonal breeder associated with a peak of estrogen production in August or September. 相似文献
118.
Hirashima A Eiraku T Shigeta Y Kuwano E Taniguchi E Eto M 《Pest management science》2002,58(11):1118-1125
Some octopamine (OA) agonists were found to suppress the calling behaviour and pheromone biosynthesis in vitro of the Indian meal moth, Plodia interpunctella (Hübner), a stored-product pest. Compounds were screened using a calling behaviour bioassay of female P interpunctella. Three active derivatives, with activity at the nanomolar level, were identified. In order of decreasing pheromonostatic activity these were: 2-(2-ethyl-6-methylanilino)oxazolidine > 2-(2,6-diethylanilino)thiazolidine > 2-(2,6-diethylanilino)oxazolidine. These compounds showed also in vitro inhibitory activities in de novo pheromone biosynthesis. Three-dimensional pharmacophore hypotheses were built from a set of 19 compounds. Among the ten common-featured models generated by the program Catalyst/HipHop, a hypothesis including a ring aromatic group (RA), a positive ionizable group (PI) and two hydrophobic aliphatic (HpA1) features was considered to be essential for inhibitory activity in the calling behaviour and pheromone biosynthesis in vitro. Active compounds mapped well onto all the RA, PI and HpA1 features of the hypothesis. Less-active compounds were shown not to achieve the energetically favourable conformation which was found in the active molecules in order to fit the 3-D common-feature pharmacophore models. The present studies demonstrate that inhibition of calling behaviour and PBAN-stimulated incorporation of radioactivity is by OA-agonistic activity. 相似文献
119.
Akihiko HAGINO Eiji INOMATA Takuya SATO Yasushi OHTOMO Yasuyuki SASAKI Yoshiaki OBARA 《Animal Science Journal》2005,76(1):55-63
This study was designed to examine the effects of the proportion of concentrate in the diet on the secretion of growth hormone (GH), insulin and insulin‐like growth factor‐I (IGF‐I) secretion and the GH‐releasing hormone (GHRH)‐induced GH response in adult sheep fed once daily. Dietary treatments were roughage and concentrate at ratios of 100:0 (0% concentrate diet), 60:40 (40% concentrate diet), and 20:80 (80% concentrate diet) on a dry matter basis. Mean plasma concentrations of GH before daily feeding (10.00–14.00 hours) were 11.4 ± 0.4, 10.1 ± 0.5 and 7.5 ± 0.3 ng/mL on the 0, 40 and 80% concentrate diet treatments, respectively. A significant decrease in plasma GH concentration was observed after daily feeding of any of the dietary treatments and these decreased levels were maintained for 8 h (0%), 12 h (40%) and 12 h (80%), respectively (P < 0.05). Plasma IGF‐I concentrations were significantly decreased 8–12 h and 4–16 h after the end of feeding compared with the prefeeding level in the 40 and 80% concentrate diet treatments, respectively (P < 0.05). GHRH injection brought an abrupt increase in the plasma GH concentrations, reaching a peak 10 min after each injection, but, after the meal, the peak plasma GH values for animals fed 40% (P < 0.05) and 80% (P < 0.01) concentrate diet were lower than that for roughage fed animals. The concentrate content of a diet affects the anterior pituitary function of sheep resulting in reduced baseline concentrations of GH and prolonged GH reduction after feeding once daily. 相似文献
120.
The quantitative relationship between the structure of 2-(arylimino) thiazolidines (AITs), arylethanolamines (AEAs) and 2-(arylalkylamino)-2-thi-azolines (AATs) and their octopamine (OA)-agonist activities against the ventral nerve cord of American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The electronic nature of a substituent was the most important factor for AAT, followed by the hydrophobic effects: the more electron-donating and the more hydrophobic the substituent, the greater the activity. The hydrophobic nature of a substituent in AEA was the most important factor, followed by the steric effects: the more hydrophobic the substituent, the greater the activity. The more electron-donating the substituent of AIT, the greater the activity. 相似文献