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131.
Natàlia Alonso 《Vegetation History and Archaeobotany》2008,17(1):75-84
Various sites in the valley of the Sant Cugat stream in Cerdanyola del Vallès (Catalonia) were subject to systematic archaeobotanical
sampling to obtain an overview of the crops and agriculture of the area during the Iron Age and late antiquity. In all cases,
the most numerous taxa were crop plants. Among these, cereals were clearly predominant at all sites investigated, especially
Hordeum vulgare var. vulgare (hulled barley) and Triticum aestivum/durum (bread or macaroni wheat), both in numbers and frequency. Other cereals, such as Triticum dicoccum (emmer) or Setaria italica (foxtail bristle-grass), were regularly present in considerably lower numbers but in fairly high frequencies. Pulses were
much less numerous, although their presence increases in terms of frequency. Among them, clearly the best represented was
Lens culinaris (lentil). The results show that the agriculture in the period considered was principally based on winter cereals, with a
gradual substitution of hulled barley by bread/hard wheat, accompanied by other cereals of minor importance, led by Triticum dicoccum (emmer), and pulses. The appearance of Vitis (grapevine) in the Iberian period is one of the important characteristics of agriculture in the Iberian world.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
132.
Presence and stability of an unusual phycoerythrin (PE) characteristically similar to R-PE are described in a terrestrial,
desiccation-tolerant cyanobacterium, Lyngbya arboricola. Extraction and purification of the PE by using acetone precipitation, gel filtration and ion-exchange chromatography resulted
in achieving a purity index (A560/A280) of up to 5.2. SDS-PAGE of the PE showed presence of 18 kDa, 20 kDa and 32 kDa bands corresponding to α, β and γ subunits
of R-PE without any other contaminating phycobiliproteins (PBPs). The absorption spectrum of the PE was distinguished by two
major peaks at 499 and 559 nm. The maximum fluorescence emission at room temperature was 578 nm. Spectroscopic and electrophoresis
characteristics of PE in the dry mats on storage at 25 ± 1°C over silica gel for 2 years remained almost unaffected. Quantitatively,
storage stability of the PE was in the order of dry mats > lyophilized > liquid state and the impact of temperature on loss
of PE was in the order of 25°C > −20°C > 4°C. The relevance of L. arboricola for production of stable unusual PE is discussed. 相似文献
133.
The objective of this investigation was to evaluate the frequency of chromosomal aberrations expressed as micronuclei (MN)
in 4–8 cell embryos generated by gamma-irradiation of female mice in the absence and in the presence of vitamin C. Female
NMRI mice were whole body exposed to 4 Gy gamma-irradiation after intraperitoneal (i.p.) injection of pregnant mare’s serum
gonadotrophin (PMSG) followed by injection of human chorionic gonadotrophin (HCG) and mating with non-irradiated NMRI male
mice. Pregnant animals were sacrificed and embryos flushed from the oviducts and fixed on slides. Cells were treated for MN
observation using standard method. To investigate the protective effect of vitamin C (ascorbic acid) on the frequency of MN,
100 mg/kg vitamin C was i.p. injected 1 h before irradiation. Results show that the frequency of MN generated in the embryos
of irradiated mother compared to those of control in the non-irradiated group increased dramatically (P < 0.001). Frequency of MN in embryos generated in irradiated female mice treated with vitamin C dramatically and statistically
decreased relative to the frequency observed in the irradiation only group (P < 0.001). This decrease returned the combined treatment group to a level that was not statistically different from the controls
(P > 0.05). Thus, irradiation of preovulatory stage oocytes leads to stable chromosome abnormalities expressed as micronuclei
in successive preimplantation embryos. Vitamin C reduces these clastogenic effects of radiation in preovulatory oocytes and
thus the reduced frequency of MN in embryos is probably due to its antioxidation and radical scavenging properties. 相似文献
134.
Marcus Clauss Hanspeter Steinmetz Ulrike Eulenberger Pete Ossent Robert Zingg Jürgen Hummel Jean-Michel Hatt 《European Journal of Wildlife Research》2007,53(1):68-72
The digestive tract of elephants is surprisingly short compared to other herbivorous mammals. However, measurements relating
the length of the intestine to the body mass of the respective individual are rare. In this study, we report such data for
an African elephant and an Asian elephant. Our data support the hypothesis that Asian elephants have a longer intestinal tract
than their African counterparts. These findings are in accord with the observation of longer retention times and higher digestion
coefficients in Asian as compared to African elephants. This difference between the species could be the reflection of slightly
different ecological niches, with Asian elephants adapted to a natural diet with a higher proportion of grass. 相似文献
135.
In order to better understand the various pathways of sucrose and starch catabolism in the anther of lily (Lilium hybrida var. “Enchantment”), invertase (EC 3.2.1.26) and amylase (EC 3.2.1.1, EC 3.2.1.2) activities were measured separately in
different fractions (anther wall, locular fluid and microspore/pollen) and correlated with the sugar content during anther
development. Our findings showed significant differences among the fractions analyzed, suggesting that the regulation of sucrose
and starch catabolism could follow distinct pathways in each fraction. Glucose and fructose amounts progressively decreased
from anther wall to fluid and from fluid to microspore/pollen. Thus, the developing pollen could act as a sink for the carbohydrates
that reach the anther. In this sense, cell wall-bound invertases seem to play a major role in soluble sugar partitioning in
the different fractions of the anther. Sucrose concentration was found to be substantially higher in the locular fluid than
in the other fractions, indicating a probable site for storage. On the other hand, the anther wall tissues could have a buffering
function, storing nutrient surplus in starch grains and thus regulating the availability of soluble sugars in the whole anther.
All these results proved the advantages of the experimental model proposed here, as well as its usefulness to investigate
sugar metabolism in Lilium anthers. 相似文献
136.
Inflorescence apices are suitable explants for the rapid in vitro propagation of Musa spp. However, the diploid and triploid banana cultivars showed different in vitro responses with respect to the hormone combinations
in Murashige and Skoog medium. The diploid cultivar (Sannachenkadali, AA) induced a maximum number of multiple shoots in 8.9 μM
6-benzyl adenine (BA) whereas the triploid cultivar (Red banana, AAA) exhibited maximum multiplication in 22.2 μM 6-benzyl
adenine. MS medium supplemented with 11.4 μM indole acetic acid and 17.8 μM BA was also suitable for shoot proliferation in
triploid cultivar but not in the diploid cultivar. The regenerated shoots were rooted in Murashige and Skoog basal medium
within 10–15 days. The rooted plantlets were transferred to vermiculite and maintained at a temperature of 25 ± 2°C for 10 days
and then at room temperature (30–32°C) for 2 weeks before transferring to potted soil compost mixture. The plantlets showed
100% survival. 相似文献
137.
Jane M. Caffrey Michael C. Murrell Cathleen Wigand Richard McKinney 《Biogeochemistry》2007,82(3):251-264
Coastal marshes represent an important transitional zone between uplands and estuaries. One important function of marshes
is to assimilate nutrient inputs from uplands, thus providing a buffer for anthropogenic nutrient loads. We examined the effects
of nitrogen (N) and phosphorus (P) fertilization on biogeochemical and microbial processes during the summer growing season
in a Spartina patens (Aiton (Muhl.)) marsh in the Narragansett Bay National Estuarine Research Reserve on Prudence Island (RI). Quadruplicate
1 m2 plots were fertilized with N and P additions, N-only, P-only, or no additions. N-only addition significantly stimulated bacterial
production and increased pore water NH4+ and NO3− concentrations. Denitrification rates ranged from 0 to 8 mmol m−2 day−1. Fertilization had no apparent effect on soil oxygen consumption or denitrification measured in the summer in intact cores
due to high core-to-core variation. P fertilization led to increased pore water dissolved inorganic phosphorus (DIP) concentrations
and increased DIP release from soils. In contrast the control and N-only treatments had significant DIP uptake across the
soil-water interface. The results suggest that in the summer fertilization has no apparent effect on denitrification rates,
stimulates bacterial productivity, enhances pore water nutrient concentrations and alters some nutrient fluxes across the
marsh surface. 相似文献
138.
A major sensory organ for the detection of pheromones by animals is the vomeronasal organ (VNO). Although pheromones control
the behaviors of various species, the effect of pheromones on human behavior has been controversial because the VNO is not
functional in adults. However, recent genetic, biochemical, and electrophysiological data suggest that some pheromone-based
behaviors, including male sexual behavior in mice, are mediated through the main olfactory epithelium (MOE) and are coupled
to the type 3 adenylyl cyclase (AC3) and a cyclic nucleotide-gated (CNG) ion channel. These recent discoveries suggest the
provocative hypothesis that human pheromones may signal through the MOE. 相似文献
139.
Heather J. Robinson Gregor M. Cailliet David A. Ebert 《Environmental Biology of Fishes》2007,80(2-3):165-179
Feeding studies can provide researchers with important insights towards understanding potential fishery impacts on marine
systems. Raja rhina is one of the most common elasmobranch species landed in central and northern California demersal fisheries, yet life history
information is extremely limited for this species and aspects of its diet are unknown. Specimens of R. rhina were collected between September, 2002 and August, 2003 from fisheries-independent trawl surveys. Percent Index of Relative
Importance values indicated that the five most important prey items in 618 stomachs of R. rhina were unidentified teleosts (31.6% IRI), unidentified shrimps (19.6% IRI), unidentified euphausiids (10.9% IRI), Crangonidae
(7.4% IRI), and Neocrangon resima (6.0% IRI). There were significant dietary shifts with increasing skate total length and with increasing depths. Smaller
skates ate small crustaceans and larger skates ate larger fishes and cephalopods. With increasing depths, diet included bentho-pelagic
teleosts and more cephalopods and euphausiids. The findings of this study are consistent with previous researchers that report
similar diet shifts in skate species with size and depth. 相似文献
140.
Fang-fang Zhuan Zhen-feng Zhang Di-ping Xu Yan-hong Si Han-Zhong Wang Ghopur Mijit 《中国病毒学》2007,22(4):316-325
lacZa-mini-attTn7 was inserted into the intergenic region between the gG and gD genes in a PRV bacterial artificial chromosome (BAC) by homologous
recombination in E. coli. The resulting recombinant BAC (pBeckerZF1) was confirmed by PCR and sequencing. Green fluorescent protein (GFP) gene was
then transposed into pBeckerZF1 by transposon Tn7 to generate pBeckerZF2. Recombinant viruses vBeckerZF1 and vBeckerZF2 were
generated by transfection with the corresponding BAC pBeckerZF1 or pBeckerZF2. The titers and cytopathic effect (CPE) observed
for by vBeckerZF1 and vBeckerZF2 was comparable to that of the parental virus vBecker3. vBeckerZF2 was serial passaged for
five rounds in cell culture, and the mini-Tn7 insertion was stably maintained in viral genome. These results show that recombinant
viruses can be rapidly and reliably created by Tn7-mediated transposition. This technology should accelerate greatly the pace
at which recombinant PRV can be generated and, thus, facilitate the use of recombinant viruses for detailed mutagenic studies.
Foundation item: Key technologies R&D program (2006BAD06A01) from the Ministry of Science and Technology of China. 相似文献