全文获取类型
收费全文 | 535篇 |
免费 | 24篇 |
专业分类
林业 | 46篇 |
农学 | 51篇 |
基础科学 | 2篇 |
96篇 | |
综合类 | 29篇 |
农作物 | 65篇 |
水产渔业 | 81篇 |
畜牧兽医 | 145篇 |
园艺 | 14篇 |
植物保护 | 30篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 16篇 |
2019年 | 18篇 |
2018年 | 22篇 |
2017年 | 25篇 |
2016年 | 28篇 |
2015年 | 14篇 |
2014年 | 28篇 |
2013年 | 60篇 |
2012年 | 37篇 |
2011年 | 31篇 |
2010年 | 34篇 |
2009年 | 22篇 |
2008年 | 35篇 |
2007年 | 19篇 |
2006年 | 13篇 |
2005年 | 13篇 |
2004年 | 10篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 14篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 4篇 |
1970年 | 5篇 |
1968年 | 7篇 |
1967年 | 4篇 |
1966年 | 6篇 |
1965年 | 2篇 |
1964年 | 1篇 |
1959年 | 1篇 |
1865年 | 1篇 |
排序方式: 共有559条查询结果,搜索用时 15 毫秒
91.
Hemagglutinating activity was identified in the roots and vegetative tissues of Bengal gram using rabbit erythrocytes. The activity in the roots appears to be similar to that of the seeds in respect to their sugar inhibition property. Seed and root extracts were found to have fetuin inhibitory agglutinating activity, whereas cotyledons showed different sugar specificity. However, 7-day cotyledons and roots from 3 and 7-day plants were also found to have galactose and N-acetyl-D-galactosamine inhibitory activity. Protein profile in different tissues during their developmental stages was analyzed by SDS-PAGE. A major band at 66 kDa was common to all tissues at different stages of their development except 3-day cotyledons where 2 major bands at 22 kDa and 74 kDa were observed. Two prominent bands at 74 kDa and 86 kDa were found along with 60 kDa protein in 3-day old roots whereas a major band at 33 kDa was found in 15-day old roots. Total protein content and specific activity of hemagglutinin were measured. Increase in specific activity with lower protein content was observed in cotyledons of 15-day old plant. Specific activity was eight times higher in the roots and four times more in leaf tissues of 7-day old plants in comparison to 15-day old plants. Stems also showed a significant increase of specific activity (p = 0.013) in 7-day old plants without any significant alteration in the protein content. 相似文献
92.
Micha?l C Fontaine Krystal A Tolley Ursula Siebert Sylvie Gobert Gilles Lepoint Jean-Marie Bouquegneau Krishna Das 《BMC ecology》2007,7(1):1
Background
We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative markers: stable isotopes (δ13C, δ15N) and trace elements (Zn, Cu, Fe, Se, total Hg and Cd), in relation to habitat characteristics (bathymetry) and geographic position (latitude). 相似文献93.
Background
Harbour porpoises Phocoena phocoena from the southern North Sea are known to display high levels of Zn and Hg in their tissues linked to their nutritional status (emaciation). The question arises regarding a potential role of metallothioneins (MTs) with regard to these high metal levels. In the present study, metallothionein detection and associated Zn, Cd, Cu and Hg concentrations were investigated in the liver and kidney of 14 harbour porpoises collected along the Belgian coast. 相似文献94.
Brojeswari Das A. Das V. K. Kothari R. Fanguiero M. de Araújo 《Fibers and Polymers》2008,9(2):225-231
The current work incorporates an experimental study on the effect of fiber cross sectional shape and fibre diameter on moisture
transmission properties of the fabric. Water vapour transmission of the fabrics was measured using the PERMETEST. In plane
liquid flow through the fabric was measured using a gravimetric in-plane wicking tester and vertical movement of liquid along
the fibres against gravity was also observed using a vertical wicking tester. With the change in shape factor and fibre diameter,
it is seen that with increase in fibre specific surface area wicking rate through fabric increases, whereas water vapour permeability
of the fabric reduces. 相似文献
95.
Yashika Walia Yogesh Kumar Tanuja Rana Pooja Bhardwaj Raja Ram Pritam Das Thakur Usha Sharma Vipin Hallan A. A. Zaidi 《Journal of General Plant Pathology》2009,75(4):307-311
Apple scar skin viroid (ASSVd) infection is a major limitation to apple fruit quality and causes huge economic losses. In surveys of apple orchards
in the northern Indian state of Himachal Pradesh, fruits with dappling symptoms were noticed. ASSVd was detected from these
fruits and molecularly characterized. Ten clones from three isolates were sequenced, of which seven were new sequence variants
of ASSVd. The clones had significant sequence variability (94–100%) with each other. Variability was more common in the pathogenic
domain of the viroid genome. Four of the clones were 330 nucleotides (nt) long, and the other six had an additional nucleotide.
Phylogenetic analysis showed close affinity of the present isolates with some Chinese and Korean isolates. The study reports
seven new variants of ASSVd and also provides the first molecular evidence of viroid infection (ASSVd) in apple in India. 相似文献
96.
S. Gandhi Doss S. P. Chakraborti S. Roychowdhuri N. K. Das K. Vijayan P. D. Ghosh 《Euphytica》2012,185(2):215-225
Sericulture is an agro-based industry, which heavily depends on mulberry (Morus spp.) for its sustainability, as mulberry leaf is the only available feed for the silkworm Bombyx mori L. Sericulture, in West Bengal and other subtropical regions in India, suffers from lack of adequate quantity of quality
mulberry leaf during the colder months, the best season for rearing the high yielding bivoltine silkworm hybrids. In order
to develop mulberry varieties, which can sustain normal growth during these colder months to yield better, efforts have been
made in different research institutes in India. The present report is part of such an effort in which accessions in germplasm
bank were screened for better growth, leaf retention and leaf yield contributing associated traits. Twenty three selected
parents were crossed, 3,500 seeds were sown, 2,700 seedlings were transplanted to progeny row trail, selected 210 hybrids
were evaluated under primary yield trial and finally nine hybrids along with a control variety were studied in detail for
all leaf yield contributing traits under final yield trial. Stability analysis was adopted to identify hybrids, which can
yield stably across seasons. The hybrids CT-44 and CT-11 out yielding the control by 17.17 and 7.11% were selected as these
hybrids yield 7.93 and 8.15 mt/ha leaf respectively during the colder months (February) for their direct use as cultivars
in West Bengal and other subtropical areas of India to sustain bivoltine sericulture to produce quality and gradable silk
fibers. 相似文献
97.
Pramoda Kumar Sahoo Mudagandur S Shekhar Abhilipsa Das Manickam Dilli Kumar Bindu R Pillai A S Sahul Hameed 《Aquaculture Research》2012,43(8):1096-1106
The present study evaluated the role of recombinant RNA‐dependent RNA polymerase (RdRp) protein of Macrobrachium rosenbergii nodavirus (MrNV) in modulating the immune response and in reducing MrNV load in infected prawn. In the first experiment, prawns (25–30 g) were injected with recombinant RdRp protein (RP) at a concentration of 0, 1.0 and 10 μg, and immune parameters and expression of some immune‐related genes were measured up to 14 days post injection (p.i.). In the second experiment, early juveniles were injected with a similar dose of RdRp and animals were challenged by immersion with MrNV. The infection status was detected in muscles by nested RT‐PCR up to 21 days post challenge. Prawn injected with higher concentration of RP showed significantly higher total haemocyte count at different period post injection. Significant up‐regulation of immune‐related genes was observed within 24 h in prawn treated with lower dose of RP and after 7 days p.i. at higher level of RP injection compared with adult control. Most of the tested samples (63%) were found to be RT‐PCR positive for MrNV at 48 h of post‐immersion challenge. After 14 days, MrNV was detected only in control prawn, while both RP‐injected groups were MrNV negative. This study elucidated the potential viral load reduction role played by RdRP in MrNV‐infected prawn. 相似文献
98.
Dinesh Kumar C. Devakumar Rajesh Kumar Aurovinda Das P. Panneerselvam Y. S. Shivay 《Journal of plant nutrition》2013,36(13):1939-1959
The nitrogen (N) fertilizer-use efficiency (20–50%) is low in rice fields in India. The neem-oil coated urea can increase N-use efficiency in lowland rice, but the desirable thickness of neem-oil coating onto urea is not known yet. Therefore, field experiments were conducted during kharif (rainy) season years 2004 and 2005 at the Research Farm of Indian Agricultural Research Institute, New Delhi to know the suitable thickness of neem-oil coating on prilled urea (PU) for increased N-use efficiency and yield. The treatments comprised of twelve combinations of four N sources (PU coated with neem-oil thickness of 0, 500, 1000 and 2000 mg kg?1 PU) and three N levels (50, 100, and 150 kg N ha?1) plus a no-N control. Prilled urea (PU) refers to the common urea available commercially in prills, which is different from urea super granules. Application of urea coated with neem-oil thickness of 1000 mg kg?1 PU resulted in significantly higher growth, yield parameters, grain yield, N uptake, and efficiency of aromatic rice (Oryza sativa L.) over uncoated PU. Nitrogen application at 122 kg ha?1 was optimum for increased yield of rice. Nitrogen-use efficiency decreased significantly and substantially with each successive increase in levels of N from 50 to 150 kg ha?1. 相似文献
99.
Swagatika Sahu Basanta Kumar Das Bibhudendu Kumar Mishra Jyotirmayee Pradhan Surya Kanta Samal Niranjan Sarangi 《Aquaculture Research》2008,39(16):1720-1730
The aim of this study was to evaluate the dietary dosages of turmeric that enhance immune response and disease resistance against the opportunistic pathogens Aeromonas hydrophila in Labeo rohita fingerlings. Hence, four different dosages of turmeric at 0.1, 0.5, 1.0 and 5.0 g kg?1 feed were given to the fingerlings of L. rohita for 60 days at 4% body weight. At every 20‐day interval, different biochemical, haematological, enzymatic and immunological parameters of fish were evaluated. After 60 days, fish were challenged with A. hydrophila. The mortality (%) was recorded on the tenth day post challenge. Most of the immune parameters including lysozyme activity, superoxide anion production and serum bactericidal activity were significantly (P<0.05) higher on 60 days of feeding of 1.0 g of turmeric per kg of feed. Challenge study indicated 100% and 89% survivability in the group of fish fed with 5.0 and 1.0 g of turmeric per kg of feed respectively. Feeding of turmeric might have maintained long‐term protection in fish by elevating the nonspecific immune system such as Nitroblue tetrazolium (NBT), lysozyme and serum bactericidal activity. The result showed that turmeric at a dose of 1.0 g kg?1 feed for 60 days provided the greatest protection to pathogen challenge. 相似文献
100.
Two outbreaks of the egg drop syndrome were observed in quail flocks maintained on a farm together with chickens. The decrease in egg production ranged from 10.6 per cent to 50.6 per cent, and the number of soft-shelled eggs increased with the decline in egg production. In both the outbreaks haemagglutination inhibiting antibodies to EDS-76 virus were detected. Fluorescent viral antigen specific to EDS-76 virus was also detected in the lining epithelial and glandular cells of the uterus. 相似文献