全文获取类型
收费全文 | 612篇 |
免费 | 43篇 |
专业分类
林业 | 84篇 |
农学 | 34篇 |
基础科学 | 3篇 |
83篇 | |
综合类 | 35篇 |
农作物 | 66篇 |
水产渔业 | 75篇 |
畜牧兽医 | 216篇 |
园艺 | 10篇 |
植物保护 | 49篇 |
出版年
2023年 | 2篇 |
2022年 | 14篇 |
2021年 | 24篇 |
2020年 | 33篇 |
2019年 | 15篇 |
2018年 | 33篇 |
2017年 | 28篇 |
2016年 | 26篇 |
2015年 | 18篇 |
2014年 | 29篇 |
2013年 | 53篇 |
2012年 | 42篇 |
2011年 | 38篇 |
2010年 | 34篇 |
2009年 | 19篇 |
2008年 | 26篇 |
2007年 | 25篇 |
2006年 | 28篇 |
2005年 | 17篇 |
2004年 | 19篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 14篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 11篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有655条查询结果,搜索用时 31 毫秒
51.
Shahzad Ali Amanullah Jan Jia Zhikuan Amir Sohail Cai Tie Wei Ting Zhang Peng Manzoor Irshad Ahmad Mati Ur Rahman Ren Xiaolong Liu Xiaoli Xu Yue Yue 《Russian Agricultural Sciences》2016,42(3-4):224-229
A field experiment was conducted on silty clay loam soil in the years 2011–2012. Two sesame (Sesamum indicum L.) cultivars (Local Black and Local White) were evaluated using various 3 different sowing dates (20th June, 10th and 30th July) and four agrotechnical level (0, 40, 80 and 120 kg N ha–1) at New Developmental Farm The University of Agriculture, Peshawar, Pakistan. The objective of this study was to evaluate the effects of sowing dates on growth, yield and oil fatty acid composition of two sesame cultivars grown under different nitrogen fertilization. Results showed that cv. Local Black was characterized by significantly higher content of oil (47%), seed yield (696 kg ha–1) and oil yield (335 kg ha–1) while cv. Local White had higher palmitic acid (8%) and linoleic acid (38.7%). Yield and its main components were positively affected by the earlier sowing date. With regard to fatty acid composition, a decrease in oleic and stearic acid and an increase in linoleic and palmitic acid were observed. At early sowing, oleic and palmitic acid decreased whereas linoleic and stearic acid increased. The decrease in the oleic/linoleic acid ratio observed at early sowing, suggests a possible role of temperature on the activity of oleate desaturase in the developing seeds. Intensive technology of cultivation (120 kg N ha–1), compared to the economical technology (40 kg N ha–1), significantly increased the seed yield of both sesame cultivars. This was due to higher number of branches, Capsules m–2, capsules plant–1, seeds capsule–1 and 1000 seed weight (g). The intensive technology of cultivation had a beneficial effect on the content of palmitic acid, linolenic acid and oleic acid in sesame seed. 相似文献
52.
Scherer SW Cheung J MacDonald JR Osborne LR Nakabayashi K Herbrick JA Carson AR Parker-Katiraee L Skaug J Khaja R Zhang J Hudek AK Li M Haddad M Duggan GE Fernandez BA Kanematsu E Gentles S Christopoulos CC Choufani S Kwasnicka D Zheng XH Lai Z Nusskern D Zhang Q Gu Z Lu F Zeesman S Nowaczyk MJ Teshima I Chitayat D Shuman C Weksberg R Zackai EH Grebe TA Cox SR Kirkpatrick SJ Rahman N Friedman JM Heng HH Pelicci PG Lo-Coco F Belloni E Shaffer LG Pober B Morton CC Gusella JF Bruns GA Korf BR 《Science (New York, N.Y.)》2003,300(5620):767-772
53.
In vitro maturation and fertilization of prepubertal and pubertal black Bengal goat oocytes 总被引:1,自引:0,他引:1
Momena Khatun Mohammad Musharraf Uddin Bhuiyan Jalal Uddin Ahmed Aminul Haque Mohammad Bozlur Rahman Mohammed Shamsuddin 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(1):75-82
Oocytes retrieval, in vitro maturation (IVM) and fertilization (IVF) efficiency are inevitable steps towards in vitro production of embryos. In the present study, these parameters were investigated in the ovaries of prepubertal (n = 31) and pubertal (n = 61) black Bengal goats obtained from a slaughterhouse. Nuclear maturation was evaluated upon aspiration and following IVM in TCM-199 (Earle''s salt with L-glutamine and sodium bicarbonate) for 27 h at 39℃ under 5% CO2 in humidified air. The oocytes retrieval and efficiency (mean ± SD) per prepubertal and pubertal goats were 5.2 ± 0.6 and 6.8 ± 0.6, and 77.3 ± 0.1% and 80.5 ± 0.6%, respectively. Anaphase I - telophase I stages differed significantly (7.3 ± 0.8 vs. 2.6 ± 0.2, p < 0.05) between the two groups of goats. After IVM, the percentages of metaphase II were significantly higher (66.3 vs. 60.3, p < 0.05) in pubertal goats than in their prepubertal counterparts. The percentages of normal in vitro fertilization (IVF) in Fert-Tyrode''s albumin lactate pyruvate of pubertal goat oocytes did not differ between Percoll and swim-up sperm separation methods (36.7 ± 0.9% vs. 32.7 ± 1.3%, p > 0.05). Furthermore, sperm capacitation by heparin alone or in combination with ionomycin did not lead to a significant increase in the normal fertilization rate (34.8 ± 1.7 vs. 32.2 ± 1.5%, respectively) in the oocytes of pubertal goats. In conclusion, the ovaries of pubertal black Bengal goats obtained from the slaughterhouse could be used for in vitro embryo production. However, further optimization of the IVM and IVF techniques are necessary for satisfactory in vitro embryo production. 相似文献
54.
Ichiyanagi T Shida Y Rahman MM Hatano Y Konishi T 《Journal of agricultural and food chemistry》2005,53(18):7312-7319
We previously determined that five rather hydrophobic metabolites appeared in blood plasma after oral administration of cyanidin 3-O-beta-D-glucopyranoside, but a group of hydrophilic metabolites still remained unidentified. In the present study, 12 hydrophilic metabolites found were collected from urine and plasma samples by high-performance liquid chromatography (HPLC) and then analyzed by tandem MS spectrometry. From the MS spectra, four metabolites out of 12 were assigned as glucuronides of cyanidin 3-O-beta-D-glucopyranoside and six out of 12 were glucuronides of the primary metabolites of cyanidin 3-O-beta-D-glucopyranoside (O-methyl cyanidin 3-O-beta-D-glucopyranoside). Extended glucuronides of cyanidin 3-O-beta-D-glucopyranoside and O-methyl cyanidin 3-O-beta-D-glucopyranoside showed their maximum plasma concentrations at 15 and 60 min (or 30 min) after oral administration, respectively. Their maximum plasma concentrations ranged from 15 to 70 nM. From the profile of urinary-excreted anthocyanins after intravenous administration, it was deduced that extended glucuronides of cyanidin 3-O-beta-D-glucopyranoside and O-methyl cyanidin 3-O-beta-D-glucopyranoside were mainly produced in the liver rather than by intestinal flora. The area under the plasma concentration curve was 0.25 micromol min/L for extended glucuronides of cyanidin 3-O-beta-D-glucopyranoside and 0.14 micromol min/L for O-methyl cyanidin 3-O-beta-D-glucopyranoside, respectively, when evaluated as cyanidin 3-O-beta-D-glucopyranoside equivalent, indicating that extended glucuronidation is a critical pathway in cyanidin 3-O-beta-D-glucopyranoside metabolism in rats. 相似文献
55.
56.
57.
W A Rahman 《Veterinary parasitology》1992,42(1-2):163-166
Faecal worm egg counts of goats from two farms in Penang Island, West Malaysia, were monitored over a period of 14 months. The faecal egg count pattern followed that of total rainfall. The humid tropical environment was favourable for the development of various species of trichostrongylid nematodes, namely Haemonchus contortus, Trichostrongylus spp., Oesophagostomum spp. and Cooperia spp. Generally, H. contortus was observed to be the predominant species, more so in the monsoon months of the year. 相似文献
58.
Wahab A. Rahman 《Tropical animal health and production》1994,26(4):235-238
Summary The prevalence of drug-resistant parasites in goats in West Malaysia has rarely been reported. Ten commercial goat farms were surveyed for resistance to anthelminthics by measuring the reduction in faecal egg counts (FECs) after treatment with levamisole, pyrantel pamoate and fenbendazole. Resistance to fenbendazole was seen in most farms; there was no evidence of resistance to levamisole but some resistance to pyrantel pamoate was detected on one farm. The significance of the findings are discussed.
Monitoreo Para Resistencia A Los Antihelminticos De Nematodos Trichoestrongiloides En Granjas Comerciales Caprinas En Malasia Occidental
Resumen Se ha informado pocas veces de la existencia de resistencia a los antihelmínticos en cabras en Malasia Occidental. Debido a esto, se monitorearon 10 granjas comerciales, midiendo la reducción en el conteo fecal de huevos después del tratamiento con levamisol, pamoato de pirantel y fenbendazol. La resistencia contra fenbendazol fue evidente en todas las granjas; no hubo evidencia de resistencia a levamisol, pero se encontró alguna resistencia a pamoato de pirantel en una de las granjas estudiadas. Se discuten el significado de estos hallazgos.
Enquete Sur Des Nematodes Trichostrongles Resistant Aux Medicaments Chez Les Chevres De Dix Fermes Commerciales Dans L'Ouest De La Malaisie
Résumé La prévalence de parasites résistant aux médicaments chez des chèvres a rarement été rapportée en Malaisie. Une enquête a été réalisée sur les chèvres de dix élevages commerciaux pour déterminer la résistance aux anthelminthiques en mesurant la réduction du nombre d'oeufs dans les fèces après traitement avec du levamisole, du pamoate de pyrantel et du fenbendazole. Les animaux de la plupart des élevages ont montré une résistance au fenbendazole mais non au levamisole alors que ceux d'un élevage ont résisté à l'action du pamoate de pyrantel. Les raisons de ces observations sont discutées.相似文献
59.
60.