全文获取类型
收费全文 | 360篇 |
免费 | 20篇 |
专业分类
林业 | 26篇 |
农学 | 21篇 |
基础科学 | 7篇 |
63篇 | |
综合类 | 22篇 |
农作物 | 37篇 |
水产渔业 | 15篇 |
畜牧兽医 | 129篇 |
园艺 | 13篇 |
植物保护 | 47篇 |
出版年
2022年 | 9篇 |
2021年 | 20篇 |
2020年 | 11篇 |
2019年 | 25篇 |
2018年 | 12篇 |
2017年 | 20篇 |
2016年 | 13篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 19篇 |
2012年 | 27篇 |
2011年 | 27篇 |
2010年 | 22篇 |
2009年 | 11篇 |
2008年 | 21篇 |
2007年 | 15篇 |
2006年 | 11篇 |
2005年 | 21篇 |
2004年 | 15篇 |
2003年 | 13篇 |
2002年 | 4篇 |
2001年 | 10篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有380条查询结果,搜索用时 15 毫秒
41.
Canine cutaneous melanocytic tumours: significance of β‐catenin and survivin immunohistochemical expression 下载免费PDF全文
42.
Corti Martina Cavalli Daniele Cabassi Giovanni Vigoni Antonio Degano Luigi Marino Gallina Pietro 《Precision Agriculture》2019,20(4):675-696
Precision Agriculture - The development of small unmanned aerial vehicles and advances in sensor technology have made consumer digital cameras suitable for the remote sensing of vegetation. In this... 相似文献
43.
44.
A procedure was developed to obtain non-embryogenic callus and regenerated lines from root segments of Zea mays grown in aseptic conditions. The activity of glutathione-S-transferases (GSTs), for non-embryogenic callus, was determined toward 1-chloro-2,4-dinitrobenzene (CDNB) and it was compared with that obtained for corn seedlings grown without hormones. For the callus masses, increases of specific activity toward CDNB and the kinetic parameter Vmax were observed with respect to corn seedlings. The procedure permitted the regenerating of tissues from callus explants, therefore the GST(CDNB) activity and the effect of the safener benoxacor on its expression were investigated for the regenerated tissues grown in agarized substrate and in liquid medium. These explants showed a constitutive GST(CDNB) activity higher than corn seedlings and this activity was increased, for both tissues, in response to the presence of the safener benoxacor in the growing medium. The GST activity for the above tissues was also assayed toward benoxacor and terbuthylazine, metolachlor and fluorodifen herbicides. Measurable GST activity was found toward some of the above chemicals and it was found to be significantly enhanced in response to benoxacor treatment. 相似文献
45.
Maria?Teresa?Dell'AbateEmail author Anna?Benedetti Alessandra?Trinchera Daniele?Galluzzo 《Biology and Fertility of Soils》2003,37(2):124-129
Carbon and nitrogen mineralisation of leather meal fertilisers were studied in two soils characterised by different respiration activity. Both C and N mineralisation were highest in the most active soil, and when leather meal was added as a powder rather than as 2- to 4- and 4- to 6-mm particles. Fast and slow soluble N pools were determined after extraction with cold water and with hot buffer, respectively. The N remaining after the second extraction with hot buffer was named slow-release N. The percentage of slow-release N rose as the size of the applied leather meal particles increased, whereas fast soluble N was highest in the coarsest (4-6 mm) fertiliser. 相似文献
46.
47.
48.
Helvécio Della Coletta-Filho Sérgio Alves Carvalho Luis Fernando Carvalho Silva Marcos Antonio Machado 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(3):593-596
Knowledge about the mechanism of transmission of systemic pathogens of citrus species is highly important for the safe movement of citrus germplasm, management of citrus mother trees, and also production of young plants. Among systemic pathogens of citrus, Xylella fastidiosa the causal agent of the citrus variegated chlorosis (CVC), is one the most important pathogens causing decline in tree vigour and productivity. Seven-year experiments were conducted to evaluate the hypothesis of seed-to-seedling transmission of X. fastidiosa. This bacterium was found colonizing the fruit (exocarp, central axis and mesocarp) and the seed parts (seed coat and endosperm plus embryo). After 7 years of PCR assay, no positive PCR detection of X. fastidiosa was confirmed in seedlings propagated from the seeds infected with X. fastidiosa. This result demonstrates the lack of seed-to-seedling transmission of this bacterium. 相似文献
49.
Chalinulasterol (1) a new chlorinated sterol disulfate was isolated from the Caribbean sponge Chalinula molitba. Its structure was elucidated using mass spectrometry and NMR experiments. The possible role of chalinulasterol as modulator of the PXR nuclear receptor was investigated but, in spite of the close structural relationship with the PXR agonist solomonsterol A (2), it showed no activity. The structural requirements for the PXR nuclear receptor activity were discussed. 相似文献
50.
Maria Antonietta Demontis Santa Olga Cacciola Marcella Orrù Virgilio Balmas Valentina Chessa Bianca Elena Maserti Laura Mascia Francesco Raudino Gaetano Magnano di San Lio Quirico Migheli 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(4):339-351
Real-time PCR assays based on SYBR? Green I and TaqMan? technologies were developed for in planta detection and quantification of Phoma tracheiphila, the mitosporic fungus causing ‘mal secco’ disease on citrus. Primers and a hybridization probe were designed on the basis
of the internal transcribed spacer (ITS) region of the nuclear rRNA genes. The real-time PCR assays were compared with a classic
isolation method in two separate experiments carried out on 6 and 24 month-old sour orange seedlings, artificially inoculated
with a conidial suspension of the pathogen. Both technologies made it possible to follow the progression of infection by P. tracheiphila, enabling detection and quantification of the target fungus prior to the development of symptoms. The detection limit was
10 copies of the cloned target sequence and 15 pg of genomic DNA extracted from fungal spores. The values of the cycle threshold
(Ct) were linearly correlated with the concentration of the target DNA, indicating that the method is suitable as a qualitative
and quantitative assay. The presence of non-target fungal DNA had no effect on the specificity of the assay, but resulted
in a 10-fold reduction of sensitivity. Total inhibition of the reaction occurred when conidia of the target pathogen were
mixed with an organic soil substrate before extracting DNA using the standard protocol, while an alternative purification
kit resulted in a significant decrease in sensitivity. Compared to classic methods, real-time PCR proved faster and easier
to perform and showed a higher sensitivity. These results suggest that real-time PCR, based on both chemistries, has a great
potential for early diagnosis of ‘mal secco’ disease and for quantitative estimation of fungal growth within host tissue. 相似文献