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991.
Zsolt Kovács Árpád Dobolyi Gábor Juhász Katalin A. Kékesi 《Neurochemical research》2010,35(3):452-464
Nucleosides are neuromodulators that have a wide range of biological roles in the brain. In order to better understand the
function of nucleosides in the human central nervous system (CNS), we constructed a nucleoside map showing the concentration
of various nucleosides and their metabolites using post mortem samples from 61 human brain areas and 4 spinal cord areas.
We evaluated in vivo tissue levels of four nucleosides (uridine, inosine, guanosine, and adenosine) and three of their metabolites
(uracil, hypoxanthine, and xanthine). The concentrations of nucleosides were unevenly distributed across different brain regions,
where the highest levels were found in the cerebral cortex and basal ganglia, whereas the lowest concentrations were located
in the locus coeruleus, the zona incerta, the substantia nigra, and the inferior colliculus. The regional differences in nucleoside
levels in the CNS may reflect the distinct physiological functions adopted by these compounds in different brain areas. 相似文献
992.
Diwakar Aggarwal Anil Kumar M. Sudhakara Reddy 《Plant Cell, Tissue and Organ Culture》2010,102(1):45-52
An efficient shoot organogenesis system has been developed from mature plants of selected elite clones of Eucalyptus tereticornis Sm. Cultures were established using nodal explants taken from freshly coppice shoots cultured on Murashige and Skoog medium
containing 58 mM sucrose, 0.7% (w/v) agar (MS medium) and supplemented with 2.5 μM benzyladenine (BA) and 0.5 μM α-naphthaleneacetic
acid (NAA). Shoot organogenesis was achieved from leaf segments taken from elongated microshoots on MS medium supplemented
with 5.0 μM BA and 1.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The addition of cefotaxime to the medium promoted shoot
differentiation, whereas carbenicillin and cephalexin inhibited shoot differentiation. Maximum shoot bud organogenesis (44.6%)
occurred in explants cultured on MS medium supplemented with 5.0 μM BA, 1.0 μM 2,4-D and 500 mg/l cefotaxime. Leaf maturity
influenced shoot regeneration, with maximum shoot organogeneisis (40.5%) occurring when the source of explants was the fifth
leaf (14–16 days old) from the top of microshoot. Shoot organogenic potential also varied amongst the different clones of
E. tereticornis. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses indicated clonal uniformity of
the newly formed shoots/plants, and these were also found to be true-to-type. 相似文献
993.
Singapore is located near the equator, off the southern tip of the Malay Peninsula. The whole country consists mostly of lowland.
It has many interesting types of natural habitats such as primary rain forest, freshwater swamp forest, mangroves, secondary
forests, shrub, grasslands, and urban parks and fields. The climate is equatorial with relatively uniform temperature and
high humidity. Unfortunately, many of the natural habitats and the native orchids which thrive there have disappeared due
to habitat destruction. Some 226 species of native orchids have been recorded in Singapore. However, of these 178 are considered
to be extinct, and only five are common. The orchid conservation programme aims to monitor existing species, explore ways
to conserve their germplasm, and increase their numbers in natural, semi-natural, and urban environments through ex-situ seedling
culture and subsequent re-introduction into appropriate habitats, including roadside trees, parks and natural areas. In the
first phase of the programme, we have successfully propagated and carried out experiments of re-introduction on five species
of native orchids, namely, Grammatophyllum speciosum, Bulbophyllum vaginatum, Bulbophyllum membranaceum, Cymbidium finlaysonianum and Cymbidium bicolor. Survival percentages 8-yr after the reintroduction events ranged from 10 to 95 for G. speciosum, the target species of the earliest re-introduction experiments. Size of the seedlings at reintroduction, host trees, and
relative humidity seemed to play significant roles in the success rate of the reintroductions. 相似文献
994.
The European bitterling, Rhodeus amarus, is a non-indigenous fish species in British fresh waters. It lays its eggs in unionid mussels which themselves are vulnerable
to fouling by the non-indigenous zebra mussel, Dreissena polymorpha. Observations from an unmanipulated natural system showed that only 27% of zebra mussel-fouled Unio pictorum hosted bitterling, while 47% of unfouled U. pictorum hosted bitterling. We conducted a field experiment in the River Great Ouse catchment, Cambridgeshire, England in May–June
2007 and 2008 to quantify the impact of zebra mussels on bitterling load in host mussels. Zebra mussel-fouled unionids were
significantly less likely to host bitterling than unfouled unionids. The number of unionids hosting bitterling did not differ
significantly whether the zebra mussels fouling the unionid were alive or dead. Bitterling appeared to discriminate against
zebra mussel-fouled unionids less as the 2007 breeding season advanced, potentially because preferred unfouled unionids had
a higher bitterling load, and were therefore relatively lower quality hosts than at the start of the breeding season. 相似文献
995.
996.
997.
Bandamaravuri Kishore Babu S. S. Reddy Mukesh K. Yadav M. Sukumar Vijendra Mishra A. K. Saxena Dilip K. Arora 《Indian journal of microbiology》2010,50(2):199-204
Genetic diversity analysis of Macrophomina phaseolina isolates obtained from different host range and diverse geographical locations in India was carried out using RAPD fingerprinting.
Of the thirteen 10-mer random primers used, primer OPB-08 gave the maximum polymorphism and the UPGMA clustering could separate
50 isolates in to ten groups at more than 65% similarity level. The ten clusters correlated well with the geographical locations
with exceptions for isolates obtained from Eastern and Western Ghats. There was a segregation of isolates from these two geographical
locations in to two clusters thus, distributing 10 genotypes in to eight geographical locations. All the isolates M. phaseolina irrespective of their host and geographical origin, exhibited two representative monomorphic bands at 250 bp and 1 kb, presence
of these bands suggests that isolates might have evolved from a common ancestor but due to geographical isolation fallowed
by natural selection and genetic drift might have segregated in to subpopulations. Genetic similarity in the pathogenic population
reflects the dispersal of single lineage in all locations in India. 相似文献
998.
999.
Mervi Laaksonen Kaisa Murdoch Juha Siitonen Gergely Várkonyi 《Journal of Insect Conservation》2010,14(1):89-98
The beetle genus Agathidium is the largest insect group documented that principally feeds on slime moulds. Agathidium pulchellum, one of the rarest Agathidium species in Europe, is listed in the EU’s Habitats Directive. We studied the habitat associations of A. pulchellum in 44 sites located in old-growth and managed forests in eastern Finland. Agathidium pulchellum occurred exclusively on the slime-mould species Trichia decipiens. The host was associated with mid-decayed aspen, spruce and birch logs, and its incidence grew with both increasing log diameter
and stand-level log density of spruce and aspen. We also observed that even if its host was present, the beetle was absent
from sites with less than 80 aspen and spruce logs per hectare. All sites with A. pulchellum were natural forests of high conservation value. Our results show that it is possible to systematically survey the occurrence
of A. pulchellum. 相似文献
1000.
Morinda citrifolia adventitious roots were cultured in shake flasks using Murashige and Skoog medium with different types and concentrations
of auxin and cytokinin. Root (fresh weight and dry weight) accumulation was enhanced at 5 mg l−1 indole butyric acid (IBA) and at 7 and 9 mg l−1 naphthalene acetic acid (NAA). On the other hand, 9 mg l−1 NAA decreased the anthraquinone, phenolic and flavonoid contents more severely than 9 mg l−1 IBA. When adventitious roots were treated with kinetin (0.1, 0.3 and 0.5 mg l−1) and thidiazuron (TDZ; 0.1, 0.3 and 0.5 mg l−1) in combination with 5 mg l−1 IBA, fresh weight and dry weight decreased but secondary metabolite content increased. The secondary metabolite content (including
1,1-diphenyl-2-picrylhydrazyl activity) increased more in TDZ-treated than in kinetin-treated roots. Antioxidative enzymes
such as catalase (CAT) and guaiacol peroxidase (G-POD), which play important roles in plant defense, also increased. A strong
decrease in ascorbate peroxidase activity resulted in a high accumulation of hydrogen peroxide. This indicates that adventitious
roots can grow under stress conditions with induced CAT and G-POD activities and higher accumulations of secondary metabolites.
These results suggest that 5 mg l−1 IBA supplementation is useful for growth and secondary metabolite production in adventitious roots of M. citrifolia. 相似文献