全文获取类型
收费全文 | 387篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
林业 | 42篇 |
农学 | 50篇 |
基础科学 | 10篇 |
97篇 | |
综合类 | 25篇 |
农作物 | 23篇 |
水产渔业 | 16篇 |
畜牧兽医 | 103篇 |
园艺 | 19篇 |
植物保护 | 23篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 10篇 |
2019年 | 14篇 |
2018年 | 11篇 |
2017年 | 14篇 |
2016年 | 18篇 |
2015年 | 14篇 |
2014年 | 11篇 |
2013年 | 37篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 18篇 |
2009年 | 9篇 |
2008年 | 16篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 2篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1996年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 13篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1974年 | 5篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 3篇 |
1966年 | 5篇 |
排序方式: 共有408条查询结果,搜索用时 46 毫秒
121.
P. Roychoudhury G.R. Pillai S.L. Pandey G.S.R. Krishna Murti G.S. Venkataraman 《Soil & Tillage Research》1983,3(1):61-65
The application of blue-green algae improved the aggregation status of rice field soils under different levels of irrigation and nitrogen fertilizer (urea) and increased the grain yield of rice significantly. 相似文献
122.
J. R. Sharma R. K. Lal A. P. Gupta H. O. Misra V. Pant N. K. Singh V. Pandey 《Plant Breeding》1999,118(5):449-452
A mutation breeding programme using gamma rays and ethyl methane sulphonate (EMS) was carried out for genetic conversion of narcotic ‘opium poppy’ into non-narcotic ‘seed poppy’. Two families contained 31 latexless (opiumless) and 23 partial latex-bearing plants which were identified in the M2 and confirmed in the M3 generations by the ‘ray-pluck’ method. Thin-layer chromatography (TLC)-densitometry of powdered capsule hulls (straw) from 22 representative plants also revealed that none of the five opium alkaloids (morphine, codeine, thebaine, papaverine and narcotine) was present in the straw. Six plants also possessed high seed yield (4.0–5.66 g/capsule vs. 3.39 g for control) and seven had a high seed oil content (50.7-53.5%). The best mutant genotype, LL-34 of the family C1-Comb-113-2, with 5.66 g/capsule seeds containing 52.6% oil was designated as cv. ‘Sujata’. This, perhaps the world's first opiumless and alkaloid-free seed poppy cultivar, offers a cheap and permanent (fundamental) solution to the global problem of opium-linked social abuse. Simultaneously, it serves as a safe and potential food crop with protein-rich seeds and healthy unsaturated seed oil. 相似文献
123.
Malik YS Chandrashekar KM Sharma K Haq AA Vaid N Chakravarti S Batra M Singh R Pandey AB 《Tropical animal health and production》2011,43(8):1475-1478
The present study describes detection of picobirnavirus (PBV) in faecal samples from bovine and buffalo calves employing the
polyacrylamide gel electrophoresis (PAGE). A total of 136 faecal samples from buffalo (n = 122) and cow calves (n = 14) exhibiting clinical signs of diarrhoea and from healthy calves were collected during 2007–2010 from subtropical (central
India) and tarai area of western temperate Himalayan foothills (Uttarakhand). The dsRNA nature of the virus was confirmed
by nuclease treatment (RNase A, RNaseT1 and DNase 1). PAGE results confirmed 3.67% (5/136) positivity for PBV, showing a typical
genomic migration pattern with two discrete bands with size of approximately 2.4 and 1.7 kbps for the larger and smaller segments,
respectively. Among the five PBV samples identified, three were from buffalo calves and one from cow calf exhibiting clinical
signs of acute diarrhoea, while one sample from non-diarrhoeic buffalo calf also showed the presence of PBV. None of the samples
showed dual infection of rotavirus and PBV. The preliminary findings indicate sporadic incidences of PBV in bovine calves
and emphasize the need for the development of better diagnostics for early detection and genetic characterization of these
emerging isolates of farm animals of economic significance. 相似文献
124.
Arun Prasad Sanjay Kumar Abdul Khaliq Ankit Pandey 《Biology and Fertility of Soils》2011,47(8):853-861
The effects of increasing levels of metals (10 and 20 mg of Cr kg-1 and 25 and 50 mg of Cd, Pb, and Ni kg-1 soil) and arbuscular mycorrhizal (AM) fungi Glomus intraradices on the yield, chemical composition of volatile oil, and metal accumulation in sweet basil (Ocimum basilicum L.) were investigated in a pot experiment. The shoot yield, content of essential oil, and root yield of sweet basil were
increased by the application of low dose of Cd, Pb, and Ni as compared to control. The application of high level of metals
had deleterious effect on the yield. In soil with low dose of metal applied, AM fungi inoculation significantly enhanced the
metal concentration in shoots and had adverse effect on the yield, whereas in soil with high dose of metal applied, AM fungal
inoculation reduced the metal concentration in shoot and had beneficial effect on the yield. The content of linalool in basil
oil was decreased and that of methyl chavicol was increased by the application of Cr, Cd, and Pb in soil as compared to control.
Similarly, the level of linalool and methyl chavicol was decreased and that of methyl eugenol was increased by the application
of Ni as compared to control. However, AM fungal inoculation led to maintain the content of linalool, methyl chavicol, and
methyl eugenol in volatile oil, which were either increased or decreased by the application of metals. We conclude that the
AM–sweet basil symbiosis could be used as a novel approach to enhance the yield and maintain the quality of volatile oil of
sweet basil under metal-contaminated soils. 相似文献
125.
Soils are the third biggest sink of carbon on the earth. Hence, suitable land uses for a climatic condition are expected to sequester optimum atmospheric carbon in soils. But, information on how climatic conditions and land uses influence carbon accumulation in the soils on the Himalayan Mountains is not known. This study reports the impact of four climatic conditions (sub-tropical, altitude: 500–1200 m; temperate 1200–2000 m; lower alpine 2000–3000 m; upper alpine, 3000–3500 m) and four land uses (forest, grassland, horticulture, agriculture) on the concentrations and stocks of soil organic carbon (SOC) in upper (0–30 cm) and deeper (30–100 cm) soil depths on the western Himalayan Mountains of India. The study also explored the drivers which influenced the SOC stock build up on the mountains. Rainfall and soil moisture showed quadratic relations, whereas temperature declined linearly with the altitude. SOC stock as well as concentration was the highest (101.8 Mg ha− 1 in 0–30 cm, 227.97 Mg ha− 1 in 0–100 cm) in temperate and the lowest in sub-tropical climate (37 Mg ha− 1 in 0–30 cm, 107.04 Mg ha− 1 in 0–100 cm). Pattern of SOC stock build up across the altitude was: temperate > lower alpine > upper alpine > sub-tropical. SOC stocks in all land uses across the climatic conditions, except agriculture in lower alpine, was higher (0.7 to 41.6%) in the deeper than upper soil depth. SOC stocks in both the depths showed quadratic relations with soil temperature and soil moisture. Other factors like fine soil particles, land-use factor and altitude influenced positively whereas slope and pH, negatively to the SOC stocks. In all climatic conditions, other than temperate, SOC stocks were greater in natural ecosystems like forests and pastures (112.5 to 247.5 Mg ha− 1) than agriculture (63 to 120.4 Mg ha− 1). In temperate climate, SOC stock in agriculture (253.6 Mg ha− 1) on well formed terraces was a little higher than forest (231.3 Mg ha− 1) on natural slope. These observations, suggest that land uses on temperate climate may be treated as potential sinks for sequestration of the atmospheric carbon. However, agriculture in subtropical climate need to be pursued with due SOC protection measures like the temperate climate for greater sequestration of the atmospheric carbon. 相似文献
126.
An experiment with eight cropping systems (pure and intercropping) with three levels of irrigations I0 , I1 and I2 based on the physiological growth stages of safflower and chickpea was conducted during the rabi (winter) season of 1983—84 and 1984—85. The eight cropping systems were CS1 — sole chickpea, CS2 — sole safflower, CS3 — paired rows of chickpea, CS4 — paired rows of safflower, CS5 — chickpea + 50% safflower, CS6 — safflower + 50% chickpea, CS7 — chickpea + 75% safflower and CS8 — safflower + 75% chickpea. Sole crop of chickpea always had higher yield component than inter-cropping. However, none of the yield components in safflower was influenced by intercropping except number and weight of capsules per plant in 1983—84 only. With regard to levels of irrigation chickpea and safflower responded to two irrigations. 相似文献
127.
V S Pandey 《Veterinary parasitology》1990,36(3-4):347-351
The abomasa of sheep grazing on natural pastures in the highveld of Zimbabwe were examined for Haemonchus contortus. Of 304 abomasa, 213 (70%) harboured H. contortus. The worm burden increased during the rains to reach the peak in February-March. This was followed by a decline with low worm loads throughout the dry season. The fourth stage larvae (L4) accounted for 1-7% of the total H. contortus population, except during July and August when they comprised 22 and 54% of the worm burden, respectively. It appears that the inhibition of H. contortus is not common in the commercial farming sector where sheep are treated very frequently. 相似文献
128.
129.
130.