全文获取类型
收费全文 | 487篇 |
免费 | 36篇 |
国内免费 | 2篇 |
专业分类
林业 | 27篇 |
农学 | 27篇 |
基础科学 | 6篇 |
123篇 | |
综合类 | 73篇 |
农作物 | 59篇 |
水产渔业 | 47篇 |
畜牧兽医 | 99篇 |
园艺 | 14篇 |
植物保护 | 50篇 |
出版年
2023年 | 4篇 |
2022年 | 20篇 |
2021年 | 22篇 |
2020年 | 20篇 |
2019年 | 30篇 |
2018年 | 31篇 |
2017年 | 23篇 |
2016年 | 22篇 |
2015年 | 23篇 |
2014年 | 17篇 |
2013年 | 38篇 |
2012年 | 22篇 |
2011年 | 34篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2008年 | 18篇 |
2007年 | 24篇 |
2006年 | 12篇 |
2005年 | 17篇 |
2004年 | 14篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有525条查询结果,搜索用时 15 毫秒
21.
Shin-Ichi Teshima Shunsuke Koshio Manabu Ishikawa Md. Shah Alam Luis Hector Hernandez Hernandez 《Journal of the World Aquaculture Society》2006,37(2):145-153
The dietary protein requirement of the freshwater prawn Macrobrachium rosenbergii to obtain the maximum body protein retention was assessed by the estimated protein needed daily for maintenance (M) and body protein increment (G). The body protein increment was estimated by quantifying body nitrogen increments when the prawn was fed high‐protein diets composed primarily of casein. The protein required for maintenance was estimated by regressing weight gains in feeding experiments using graded dietary levels of casein. The true daily retention (R) or increase in body protein of the prawn corresponds to the sum of M and G. The values of M, G, and R determined in the present study were 3.86, 0.24, and 4.10 g/kg body weight/d, respectively. On the basis of the daily body protein increment and the net protein utilization of casein (58%), dietary protein requirement of the juvenile M. rosenbergii for maximum body protein retention was suggested to be about 7.1 g/kg body weight/d. 相似文献
22.
Saiful Izwan Abd Razak Noor Fadzliana Ahmad Sharif Nadirul Hasraf Mat Nayan 《Fibers and Polymers》2014,15(6):1107-1111
This research work reports new electrically conductive paper made of pineapple leaf fiber and polyaniline (PALF/PANI). The conductive paper shows remarkable preservation of mechanical properties while achieving its conductive state. Also it was found that, the amount of PANI needed to achieve the conductivity transformation is as low as 5 wt.%. 相似文献
23.
Shaharudin Mohamad Azimi Zaki Noorhariza Mohd Saleh Mohd Nazre Mohd Noor Normah Midin Mohd Razik 《Genetic Resources and Crop Evolution》2022,69(7):2291-2299
Genetic Resources and Crop Evolution - Mangosteen (Garcinia mangostana var. mangostana) is an obligate apomictic species which does not require a fertilization process to produce seeds. The absence... 相似文献
24.
M. A. Cheema M. A. Malik A. Hussain S. H. Shah & S. M. A. Basra 《Journal of Agronomy and Crop Science》2001,186(2):103-110
A field study was conducted to investigate the influence of variable rates of application of N and P fertilizers in splits at various times on the growth and the seed and oil yields of canola (Brassica napus L.) during 1995–97. Rates of fertilizer application were 0 and 0 (F0), 60 and 0 (F1), 0 and 30 (F2), 60 and 30 (F3), 90 and 60 (F4) and 120 and 90 (F5) kg N ha?1 and kg P2O5 ha?1. All the P was applied at sowing while N was applied in splits, i.e. all at sowing, half at sowing and half with first irrigation, or half at sowing and half at flowering. The responses of growth, seed yield and components of yield were consistent in both years. Increasing the rate of fertilizer application from F4 (90/60 kg N/P2O5 ha?1) to F5 (120/90 kg N/P2O5 ha?1) increased the leaf area index (LAI) relative to the control and to lower rates of fertilizer application. For both crops, application of 90/60 kg N/P2O5 ha?1 significantly enhanced total dry matter (TDM) and seed yield. Seed yield increased mainly due to a greater number of pods per plant and seeds per seed‐pod. The time of fertilizer application did not significantly affect seed yield or components of yield in either season. Oil yield generally followed seed yield, increasing with increasing rate of fertilizer application up to 90/60 kg N/P2O5 ha?1. The maximum oil contents were obtained from the control. The results show that seed and oil yields of canola were maximized at the F4 (90/60 kg N/P2O5 ha?1) rate of application under the agro‐ecological conditions of Faisalabad, Pakistan. 相似文献
25.
26.
27.
目前已明确番茄抗晚疫病R基因表现明显的株龄相关抗性(Age-related Resistance,ARR),但抗晚疫病QTL的抗性规律尚不明确。以携带抗晚疫病基因Ph-3的栽培种番茄(Solanum lycopersicum)‘CLN2037B’和野生种醋栗番茄(S.pimpinellifolium)‘L3708’以及易感病材料栽培种番茄(S.lycopersicum)‘LA2818’为对照,对含有抗晚疫病QTL的多毛番茄(S.habrochaites)‘LA2099’、‘LA1033’和‘LA1777’是否也存在株龄相关抗性进行了分析。结果表明,携带抗晚疫病QTL的3个材料的6叶期和9叶期植株病情级数均比3叶期明显降低,表明QTL抗性与株龄相关。利用乙烯、水杨酸和茉莉酸素合成或缺失的突变体和病毒诱导基因沉默(Virus Induced Gene Silencing,VIGS)技术,初步明确了乙烯和水杨酸参与6叶期Ph-3基因介导的对晚疫病的抗性,而茉莉酸不参与。 相似文献
28.
29.
Hafiz Mohkum Hammad Abdul Khaliq Farhat Abbas Wajid Farhad Shah Fahad Muhammad Aslam 《Communications in Soil Science and Plant Analysis》2020,51(10):1406-1422
ABSTRACT Organic amendments in the soil perform better than synthetic fertilizers in regards to soil fertility and sustainable crop productivity. Experiments were conducted to compare the effects of organic and synthetic fertilizers on soil fertility and wheat (Triticum aestivum L.) productivity. Soil fertility and protein contents of wheat grains (13.2% and 13.3% during 2005–06 and 2006–07, respectively) were improved by organic amendments. However, synthetic fertilizer (at the rate of 150, 100, and 60 kg ha?1 N, P2O5, and K2O, respectively) applications resulted in the maximum grain yield (4.05 and 4.46 t ha?1 during 2005–06 and 2006–07, respectively). The observed and simulated soil organic carbon (SOC) reasonably agreed during RothC model validation (R 2 = 0.99). Economic analysis showed the maximum net profit and relative increase in income ($729 US ha?1 and 309%, respectively) from inorganic treatment. Application of synthetic fertilizers increased grain yield and farm profit while organic manure enhanced grain quality. The RothC model had potential for determining the SOC in organic farming under arid environment. 相似文献
30.
Nisar M Kaleem WA Khan I Adhikari A Khan N Shah MR Khan IA Qayum M Samiullah Ismail M Aman A 《Fitoterapia》2011,82(7):1008-1011
Zizyphus oxyphylla Edgew is used in Pakistan as a folk medicinal remedy for inflammatory conditions, pains especially rheumatic pain, fevers, allergy and diabetes. The aim of the current study was to scientifically validate the folk use of Z. oxyphylla Edgew by using the isolated compound in vitro and in vivo levels. Kushecarpin A was isolated from ethyl acetate fraction of the plant crude extract. Molecular docking simulations predicted Kushecarpin A as a potential new lipoxygenase (LOX) inhibitor. Kushecarpin A showed significant lipoxygenase inhibition (IC50: 7.2 ± 0.02 μM) thus validated computational prediction. It also exhibited significant and highly significant inhibition (p < 0.05 and p < 0.01) of carrageenan-induced hind paw oedema at the doses of 5, 10 and 20 mg/kg. Kushecarpin A seems to be a potentially new anti-inflammatory compound responsible for anti-inflammatory activities of Z. oxyphylla Edgew. In vitro and in vivo anti-inflammatory inflammatory activities were found in good agreement with the folk medicinal use of Z. oxyphylla Edgew in inflammatory disorders. 相似文献