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Isolation and identification of granule-associated proteins relevant for poly(3-hydroxyalkanoic acid) biosynthesis in Chromatium vinosum D 总被引:1,自引:0,他引:1
Matthias Liebergesell Bernhard Schmidt Alexander Steinbüchel 《FEMS microbiology letters》1992,99(2-3):227-232
Abstract Poly(3-hydroxybutyric acid) granules, which harbored only four major granule-associated proteins as revealed by SDS polyacrylamide gel electrophoresis, were isolated from crude cellular extracts of Chromatium vinosum D by centrifugation in a linear sucrose gradient. N-Terminal amino acid sequence determination identified two proteins of M r 41 000 and M r 40 000 as the phaE Cv and phaC Cv translational products, respectively, of C. vinosum D. In a previous study it was shown that both proteins are required for the expression opf poly(3-hydroxyalkanoic acid) synthase activity. The N-terminus of the third protein ( M r 17 000) exhibited no homology to other proteins. Lysozyme, which was during purification of the granules, exhibited a strong affinity to PHB granules and was identified as the fourth protein enriched with the granules. 相似文献
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Cloning and Mapping of a Novel Nodulation Region from Bradyrhizobium japonicum by Genetic Complementation of a Deletion Mutant 总被引:4,自引:2,他引:2
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The phenotypes of a set of Bradyrhizobium japonicum 110 mutants with large deletions in the region of symbiotic gene cluster I were tested. The majority of the mutants showed a delayed nodulation on soybean and, by mixed-infection experiments, were found to be strongly reduced in their competitiveness. Phenotypic comparison of mutants with different deletion endpoints allowed a preliminary localization of two genomic regions, called nod-1 and nod-2, which were required for normal nodulation on soybean. Loss of nod-1 was found to result in a Nod− phenotype on cowpea, mung bean, and siratro. A recombinant cosmid was identified which fully restored nodulation ability of a mutant lacking nod-1. Using Tn5-containing derivatives and subclones of this cosmid for complementation, we delimited the nod-1 region to a DNA segment of 3.1 to 3.5 kilobase pairs. 相似文献
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J H Scharf 《Gegenbaurs morphologisches Jahrbuch》1986,132(4):445-460
Some remarks are passed on the spelling of medical and scientific technical terms in German. In the present writer's opinion, the orthography according to Duden disfigures words from Latin origin for the most part since Latin c is written as a k before a, o, u and as a z before e and i. Also words of Greek origin are murdered if borrowed via Latin: x becomes c in Latin and than z in German if before e and i. An alternative recommendation given by Eschenbach could be acceptable for the most terms of Latin source but not for such borrowed from Greek. Especially Eschenbach is up to mischief if he proposes his alternative orthography also for words which are borrowed from Latin 1,000 years ago and are used by everybody in the colloquial German language. The better system of orthographic handling the Latin- and Greek-derived terms in German is published by Jansen (1907). 相似文献
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In anesthetized mongrel dogs we measured the blood flow in the left phrenic artery (Qdi), using an electromagnetic flow probe, before and during supramaximal phrenic nerve stimulation (pacing). This was done at constant respiratory rate (24/min) but at three different stimulation frequencies at a duty cycle of 0.4 (20, 50, and 100 Hz) and at three different duty cycles at a stimulation frequency of 50 Hz (duty cycle = 0.2, 0.4, and 0.8). Qdi was unchanged during diaphragm contraction until transdiaphragmatic pressure (Pdi) was greater than approximately 11 cmH2O, whereafter it began to decrease, reaching zero at Pdi approximately 20 cmH2O. Thus, when Pdi was greater than 21 cmH2O, all flow occurred during relaxation. Qdi averaged over the entire respiratory cycle (Qt) was less at duty cycle = 0.8 than under the other conditions. This was because of decreasing length of relaxation phase rather than a difference of relaxation phase flow (Qr), which was maximal during all conditions of phrenic stimulation. During pacing-induced fatigue, Qt actually rose slightly as Pdi fell. This was due to an increase in contraction phase flow while Qr remained constant. The relationship between Qt and tension-time index was not unique but varied according to the different combinations of duty cycle and stimulus frequency. 相似文献
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In 32 corpses, either fresh or fixed, the deviations of the two heads (musculus vastus medialis longus and musculus vastus medialis obliquus) of the vastus medialis muscle from the long axis of the femur were measured. The deviations were between 15 and 18 degrees medially for the m. vastus medialis longus and between 46 and 52 degrees medially for the m. vastus medialis obliquus. Anatomical dissections of the vastus medialis muscle in 115 fixed thigh specimens could always demonstrate a clear separation between a long head of the muscle that inserts at the base (m. vastus medialis longus) and a short head (m. vastus medialis obliquus) that inserts at the medial margin of the patella. The plane of separation could be identified by a femoral nerve's branch in every case. In 17 instances the nerve's localization was superficial, in 57 in an areolar fascial plane, and in the depth between the muscles in 41 instances. The ramification of the femoral nerve's branch that runs along the separation plane showed four types of variation. With these investigations it was possible to distinguish between two individual heads of the vastus medialis muscle not only with regard to its function, but also to its anatomy. 相似文献
27.
The tissue distributions of sinapic acid esters (1-sinapoylglucose, sinapolyl-l-malate, 6,3-disinapoylsucrose), kaempferol glycosides, free malic acid and of the enzyme involved in the synthesis of sinapoyl-l-malate, 1-sinapoylglucose: l-malate sinapoyltransferase (SMT), have been investigated in cotyledons of Raphanus sativus L. seedlings. The kaempferol glycosides were mainly localized in the upper epidermis. The sinapoyl esters were found in all tissues, but differed markedly in their concentrations. While disinapoylsucrose was localized predominantly in the mesophyll, most sinapoylmalate was found in the epidermal layers, as was most SMT activity. Ultraviolet microscopy and microfluorospectrophotometry of isolated epidermal peels indicated that the epidermal sinapoyl esters were restricted to guard cells, guard mother cells and adjacent epidermal cells. Upon excitation by UV light (365 nm) these exhibited strong blue fluorescence with an emission maximum at about 480 nm. Our results indicate a highly tissue-and cell-specific secondary metabolism in Raphanus cotyledons and indicate that the biosynthesis of sinapoylmalate is intimately related to the malic-acid metabolism of the guard cells.Abbreviations HPLC
high-performance liquid chromatography
- SMT
1-sinapoylglucose: l-malate sinapoyltransferase 相似文献
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