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131.
132.
133.
Many different cultivation techniques and inoculum products of the plant-beneficial arbuscular mycorrhizal (AM) fungi have
been developed in the last decades. Soil- and substrate-based production techniques as well as substrate-free culture techniques
(hydroponics and aeroponics) and in vitro cultivation methods have all been attempted for the large-scale production of AM
fungi. In this review, we describe the principal in vivo and in vitro production methods that have been developed so far.
We present the parameters that are critical for optimal production, discuss the advantages and disadvantages of the methods,
and highlight their most probable sectors of application. 相似文献
134.
Fenpropimorph and fenhexamid impact phosphorus translocation by arbuscular mycorrhizal fungi 总被引:1,自引:0,他引:1
Fenpropimorph and fenhexamid are sterol biosynthesis inhibitor (SBI) molecules widely used to control diseases in agriculture.
Both molecules, at increasing concentrations, have been shown to impact on the non-target arbuscular mycorrhizal (AM) fungi.
Root colonization, spore production and mycelium architecture, including the branched absorbing structures which are thought
to be involved in phosphorus (P) uptake, were affected. In the present study, we investigated the capacity of Glomus sp. MUCL 43204 to take up, transfer and translocate labelled P to Medicago truncatula in the presence of these SBI molecules. We used a strict in vitro cultivation system associating an autotrophic plant of
M. truncatula with the AM fungus. In addition, the effects of both SBI molecules on the proportion of hyphae with alkaline phosphatases
(ALP), succinate dehydrogenase (SDH) activity and on the expression of the mycorrhiza-specific plant phosphate transporter
MtPT4 gene were examined. We demonstrated that the two SBI molecules impacted the AM fungus. This was particularly evidenced
for fenpropimorph. A decrease in P transport and ALP and SDH activities associated with the extraradical mycelium and MtPT4 expression level was noted. These three factors were closely related to the development of the AM fungus, suggesting a direct
impact not only on the AM fungal growth but also on the physiology and metabolic activities of the AM fungus. These results
further emphasized the interest on the autotrophic in vitro culture system as an alternative to pot experiments to investigate
the mechanisms behind the impact of disease control molecules on the non-target AM fungal symbionts. 相似文献
135.
C��cile Brun 《Vegetation History and Archaeobotany》2011,20(2):135-142
The focus of palaeoenvironmental sciences on past human activities and their impact on the environment necessitates a precise
understanding of the history and functioning of past and present anthropogenic ecosystems. A process is outlined which uses
palaeoenvironmental and historical documentation as well as present-day observations of vegetational changes from two different
plant communities, which are characterised by a very specific anthropogenic flora: arable weeds and ruderals. This study is
coupled with modern pollen deposition data to deduce a set of pollen types characteristic of the range of human activities
practised in eastern France, a region rich in pollen data. First, phytogeographical analysis of the evolution of these plant
communities since the Neolithic enables the comparison to be validated. By distinguishing between native plants and aliens
introduced long ago (archaeophytes), or more recently (neophytes), and by refining their ecological characteristics, the method
also enables identification of species that are strong indicators of human activities. Next, local pollen deposition in these
vegetation types is examined with a number of statistical analyses (PCIA, Davis indices), confirming the relationships between
a given vegetation community, its theoretical pollen rain and its actual pollen rain, thus distinguishing local and regional
pollen indicators. Lastly, comparison of the results obtained by these two approaches leads to a critical synthesis of the
traditional anthropogenic pollen indicators (Behre’s “indicator species”) in the study area and to the establishment of more
specific local pollen indicators. 相似文献
136.
Charl��ne Bouchaud Margareta Tengberg Patricia Dal Pr�� 《Vegetation History and Archaeobotany》2011,20(5):405-417
The discovery of seeds and textiles from Gossypium (cotton) in Achaemenian levels of the mid-6th–late 4th century b.c. at Qal’at al-Bahrain, Bahrain and in early 1st millennium a.d. at Mada’in Salih, Saudi Arabia, reveals the role played by the Arabian Peninsula as a textile production centre during the
centuries before and after the beginning of the Christian era. Both these sites were situated on important trade routes, overseas
(Qal’at al-Bahrain) and overland (Mada’in Salih), and it is likely that at least part of the cotton production was intended
for trade, complementing and perhaps competing with other sources of cotton textiles in the contemporary Middle East. In the
arid climate of the Arabian Peninsula, cotton was probably grown in association with irrigated date palm gardens where a wide
array of other crops was grown, as is shown by the analysis of charred seeds and wood from occupation levels at both sites.
The present article places these particular finds in the larger context of cotton cultivation in the Middle East and India. 相似文献
137.
138.
Jannik E. Jakobsen Juan Li Peter M. Kragh Brian Moldt Lin Lin Ying Liu Mette Schmidt Kjeld Dahl Winther Brian Dall Schyth Ida E. Holm G��bor Vajta Lars Bolund Henrik Callesen Arne Lund J?rgensen Anders Lade Nielsen Jacob Giehm Mikkelsen 《Transgenic research》2011,20(3):533-545
Modelling of human disease in genetically engineered pigs provides unique possibilities in biomedical research and in studies of disease intervention. Establishment of methodologies that allow efficient gene insertion by non-viral gene carriers is an important step towards development of new disease models. In this report, we present transgenic pigs created by Sleeping Beauty DNA transposition in primary porcine fibroblasts in combination with somatic cell nuclear transfer by handmade cloning. Göttingen minipigs expressing green fluorescent protein are produced by transgenesis with DNA transposon vectors carrying the transgene driven by the human ubiquitin C promoter. These animals carry multiple copies (from 8 to 13) of the transgene and show systemic transgene expression. Transgene-expressing pigs carry both transposase-catalyzed insertions and at least one copy of randomly inserted plasmid DNA. Our findings illustrate critical issues related to DNA transposon-directed transgenesis, including coincidental plasmid insertion and relatively low Sleeping Beauty transposition activity in porcine fibroblasts, but also provide a platform for future development of porcine disease models using the Sleeping Beauty gene insertion technology. 相似文献
139.
Compartmentalization and ultrastructural alterations induced by chromium in aquatic macrophytes 总被引:1,自引:0,他引:1
Pedro A. Mangabeira Aluane S. Ferreira Alex-Alan F. de Almeida Val��ria F. Fernandes Emerson Lucena Vania L. Souza Alberto J. dos Santos J��nior Arno H. Oliveira Marie F. Grenier-Loustalot Fr��derique Barbier Delmira C. Silva 《Biometals》2011,24(6):1017-1026
The aim of the present study was to identify the sites of accumulation of Cr in the species of macrophytes that are abundant in the Cachoeira river, namely, Alternanthera philoxeroides, Borreria scabiosoides, Polygonum ferrugineum and Eichhornia crassipes. Plants were grown in nutritive solution supplemented with 0.25 and 50 mg l?1 of CrCl3·6H2O. Samples of plant tissues were digested with HNO3/HCl in a closed-vessel microwave system and the concentrations of Cr determined using inductively-coupled plasma mass spectrometry (ICP-MS). The ultrastructure of root, stem and leaf tissue was examined using transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) in order to determine the sites of accumulation of Cr and to detect possible alterations in cell organelles induced by the presence of the metal. Chromium accumulated principally in the roots of the four macrophytes (8.6?C30 mg kg?1 dw), with much lower concentrations present in the stems and leaves (3.8?C8.6 and 0.01?C9.0 mg kg?1 dw, respectively). Within root tissue, Cr was present mainly in the vacuoles of parenchyma cells and cell walls of xylem and parenchyma. Alterations in the shape of the chloroplasts and nuclei were detected in A. philoxeroides and B. scabiosoides, suggesting a possible application of these aquatic plants as biomarkers from Cr contamination. 相似文献
140.
Aleida J. Sandoval Doralys Guilarte Jos�� A. Barreiro Elissabetta Lucci Alejandro J. M��ller 《Food biophysics》2011,6(3):424-432
The effectiveness of thymol as an antimicrobial agent during the determination of equilibrium moisture sorption data at high-water
activities (0.50–0.98) was studied at 5, 23, and 45 °C in oat flour. The static gravimetric (SG) method (with and without
added thymol) and the dynamic vapor sorption technique (DVS) were used. Microbial growth in samples conditioned in these environments
at temperatures of 5 and 45 °C was null indicating no need for the use of thymol at these temperatures. However, samples confined
in environments kept at 23 °C, when the SG method was used, needed addition of thymol since mold growth took place in its
absence. The statistical comparison between experimental equilibrium moisture content (EMC) mean values showed that, at 45 °C,
EMC values obtained using the SG technique with added thymol were significantly higher than those obtained without thymol
by both SG and DVS techniques. This could indicate an interaction of thymol with food components or absorption by lipids present.
Therefore, caution must be exerted when using thymol as an antimicrobial agent at elevated temperatures and high equilibrium
relative humidity. Moisture adsorption isotherms for oat flour were determined using a DVS technique and no isotherm crossover
with temperature, as previously reported for this product using thymol as an antimicrobial agent, was exhibited. Moisture
sorption data obtained in this work by DVS can be considered more accurate than those previously reported for oat flour, since
no external agent was involved during isotherm determinations. 相似文献