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81.
Sargent DJ Geibel M Hawkins JA Wilkinson MJ Battey NH Simpson DW 《Annals of botany》2004,94(6):787-796
BACKGROUND AND AIMS: The aims of this investigation were to highlight the qualitative and quantitative diversity apparent between nine diploid Fragaria species and produce interspecific populations segregating for a large number of morphological characters suitable for quantitative trait loci analysis. METHODS: A qualitative comparison of eight described diploid Fragaria species was performed and measurements were taken of 23 morphological traits from 19 accessions including eight described species and one previously undescribed species. A principal components analysis was performed on 14 mathematically unrelated traits from these accessions, which partitioned the species accessions into distinct morphological groups. Interspecific crosses were performed with accessions of species that displayed significant quantitative divergence and, from these, populations that should segregate for a range of quantitative traits were raised. KEY RESULTS: Significant differences between species were observed for all 23 morphological traits quantified and three distinct groups of species accessions were observed after the principal components analysis. Interspecific crosses were performed between these groups, and F2 and backcross populations were raised that should segregate for a range of morphological characters. In addition, the study highlighted a number of distinctive morphological characters in many of the species studied. CONCLUSIONS: Diploid Fragaria species are morphologically diverse, yet remain highly interfertile, making the group an ideal model for the study of the genetic basis of phenotypic differences between species through map-based investigation using quantitative trait loci. The segregating interspecific populations raised will be ideal for such investigations and could also provide insights into the nature and extent of genome evolution within this group. 相似文献
82.
Marlies?Klee Barbara?ZachEmail author Hans-Peter?Stika 《Vegetation History and Archaeobotany》2004,13(2):131-142
Late Holocene climatic changes caused a large scale regression of the Lake Chad shoreline followed by an expansion of settlements into previously unexplored territories. Numerous Final Stone Age sites of the Gajiganna Culture (1,800 to 800 b.c.) in the Lake Chad Basin (northeast Nigeria) yielded plant impressions in potsherds. The ceramics of Phase I (1,800–1,400 b.c.) were mineral tempered, and plant impressions, mainly of Paniceae, were caused only by incidental inclusion. In contrast, a considerable number of the sherds from Phase II (1,500–800 b.c.) were intentionally tempered with chaff derived from domesticated pearl millet (Pennisetum glaucum), wild Paniceae and wild rice species (Oryza cf. barthii
and O. cf. longistaminata). This plant spectrum suggests the exploitation of the wet wild areas, and also the cultivation of pearl millet on sandy soils. The evidence suggests that agricultural practices were established late and were introduced from elsewhere. During the time of seasonally occupied sites in Phase I, the subsistence strategy was based on herding, fishing, and gathering, while in Phase II there are signs of permanent settlements and agriculture. The evidence from the plant impressions indicates that in the Final Stone Age Gajiganna Culture around 1,000–800 b.c., pearl millet became well established while the gathering of wild millets and rice was still practised.*Klee et al. (2000), Zach and Klee (2003) 相似文献
83.
D. Ćalić S. Zdravković-Korać S. Jevremović M. Guć-Šćekić Lj. Radojević 《Biologia Plantarum》2003,47(2):289-292
Suspension culture was more efficient method for haploid production than anther culture. All analysed androgenic regenerants
originating from embryogenic microspores in suspension culture of Aesculus hippocastanum L. had a haploid number of chromosomes (n=20), while 50 % of those derived from anther culture were diploids.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
84.
Sentsui H Inoshima Y Murakami K Akashi H Purevtseren B Pagmajav O Sugiura T 《Microbiology and immunology》2001,45(1):45-50
Cross reactivity of equine infectious anemia virus (EIAV) antigen prepared using a recombinant baculovirus containing the p26 gene of strain P337-V70 was examined by the agar gel immunodiffusion (AGID) test and enzyme-linked immunosorbent assay (ELISA). Serum samples serially collected from 13 horses experimentally infected with six different EIAV strains (two or three horses per strain) were subjected to the test. Positive reactions were observed in the AGID test and ELISA before or soon after the first feverish period and continued persistently in most of the horses. The results with recombinant antigens were essentially the same as those with the virion antigen prepared from horse cell cultures both in the AGID test and ELISA. The reactivities of the antigens were further compared using serum samples collected from horses in 1999 in certain districts of Mongolia where equine infectious anemia has been prevalent, and from horses in Japan in 1973 when EIA had not been eliminated completely from Japanese horses. These results were completely concurrent. Generally, recombinant antigens have high specificity but low cross reactivity to heterologous strains. However, the present study showed that the recombinant EIAV p26 antigen has cross reactivity to the heterologous strain and is useful for diagnosis of EIA in the field. 相似文献
85.
Iwamoto R Kubota H Hosoki T Ikehara K Tanaka M 《Archives of biochemistry and biophysics》2002,398(2):203-212
A glucosamine-induced novel alcohol dehydrogenase has been isolated from Agrobacterium radiobacter (tumefaciens) and its fundamental properties have been characterized. The enzyme catalyzes NAD-dependent dehydrogenation of aliphatic alcohols and amino alcohols. In this work, the complete amino acid sequence of the alcohol dehydrogenase was determined by PCR method using genomic DNA of A. radiobacter as template. The enzyme comprises 336 amino acids and has a molecular mass of 36 kDa. The primary structure of the enzyme demonstrates a high homology to structures of alcohol dehydrogenases from Shinorhizobium meliloti (83% identity, 90% positive) and Pseudomonas aeruginosa (65% identity, 76% positive). The two Zn(2+) ion binding sites, both the active site and another site that contributed to stabilization of the enzyme, are conserved in those enzymes. Sequences analysis of the NAD-dependent dehydrogenase family using a hypothetical phylogenetic tree indicates that these three enzymes form a new group distinct from other members of the Zn-containing long-chain alcohol dehydrogenase family. The physicochemical properties of alcohol dehydrogenase from A. radiobacter were characterized as follows. (1) Stereospecificity of the hydride transfer from ethanol to NADH was categorized as pro-R type by NMR spectra of NADH formed in the enzymatic reaction using ethanol-D(6) was used as substrate. (2) Optimal pH for all alcohols with no amino group examined was pH 8.5 (of the C(2)-C(6) alcohols, n-amyl alcohol demonstrated the highest activity). Conversely, glucosaminitol was optimally dehydrogenated at pH 10.0. (3) The rate-determining step of the dehydrogenase for ethanol is deprotonation of the enzyme-NAD-Zn-OHCH(2)CH(3) complex to enzyme-NAD-Zn-O(-)CH(2)CH(3) complex and that for glucosaminitol is H(2)O addition to enzyme-Zn-NADH complex. 相似文献
86.
Microsatellite polymorphism in natural populations of wild emmer wheat,Triticum dicoccoides,in Israel 总被引:5,自引:0,他引:5
Fahima T Röder MS Wendehake K Kirzhner VM Nevo E 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(1):17-29
Diversity in 20 microsatellite loci of wild emmer wheat, Triticum dicoccoides, was examined in 15 populations (135 genotypes) representing a wide range of ecological conditions of soil, temperature, and
water availability, in Israel and Turkey. An extensive amount of diversity at microsatellite loci was observed despite the
predominantly selfing nature of this plant species. The 20 Gatersleben wheat microsatellites (GWM), representing 13 chromosomes
of genomes A and B of wheat, revealed a total of 364 alleles, with an average of 18 alleles per GWM marker (range: 5–26).
The proportion of polymorphic loci per population averaged 0.90 (range: 0.45– 1.00); genic diversity, He, averaged 0.50 (range 0.094– 0.736); and Shannon’s information index averaged 0.84 (range 0.166–1.307). The coefficients
of genetic distance between populations were high and averaged D=1.862 (range 0.876–3.320), an indication of sharp genetic divergence over short distances. Interpopulation genetic distances
showed no association with geographic distance between the population sites of origin, which ruled out a simple isolation
by distance model. Genetic dissimilarity values between genotypes were used to produce a dendrogram of the relationships among
wild wheat populations by the unweighted pair-group method with arithmetic averages (UPGMA). The results showed that all the
wild emmer wheat populations could be distinguished. Microsatellite analysis was found to be highly effective in distinguishing
genotypes of T. dicoccoides, originating from diverse ecogeographical sites in Israel and Turkey, with 88% of the 135 genotypes correctly classified into
sites of origin by discriminant analysis. Our present microsatellite results are non-random and in agreement with the previously
obtained allozyme and RAPD patterns, although the genetic-diversity values obtained with microsatellites are much higher.
Significant correlates of microsatellite markers with various climatic and soil factors suggest that, as in allozymes and
RAPDs, natural selection causes adaptive microsatellite ecogeographical differentiation, not only in coding, but most importantly
in non-coding genomic regions. Hence, the concept of ”junk DNA” needs to be replaced by at least partly regulatory DNA. The
obtained results suggest that microsatellite markers are useful for the estimation of genetic diversity in natural populations
of T. dicoccoides and for the tagging of agronomically important traits derived from wild emmer wheat.
Received: 27 February 2001 / Accepted: 22 March 2001 相似文献
87.
Capela R Purse BV Pena I Wittman EJ Margarita Y Capela M Romão L Mellor PS Baylis M 《Medical and veterinary entomology》2003,17(2):165-177
Surveillance of Culicoides (Diptera: Ceratopogonidae) biting midge vectors was carried out at 87 sites within a 50 x 50 km grid distributed across Portugal, using light trap collections at the time of peak midge abundance. Culicoides imicola (Kieffer) made up 66% of the 55 937 Culicoides in these summer collections. It was highly abundant in the central eastern portion of Portugal, between 37 degrees 5' N and 41 degrees 5' N, and in a band across to the Lisbon peninsula (at around 38 degrees 5' N). Of all the complexes, its distribution was most consistent with that of previous outbreaks of Culicoides-borne disease, suggesting that it may remain the major vector in Portugal. Its distribution was also broadly consistent with that predicted by a recent climate-driven model validating the use of remote sensing datasets for modelling of Culicoides distribution. Adult C. imicola were found to have overwintered at 12 of 20 sites re-surveyed in winter but it did so in very low numbers. Culicoides obsoletus (Meigen) and Culicoides pulicaris (Linnaeus) complex midges were widespread despite their low summer abundance. The observed coincidence of high abundances of C. imicola and high abundances of C. pulicaris in summer lead us to suggest that C. imicola could bring African horse sickness virus or bluetongue virus into contact with C. pulicaris and the latter complex, together with C. obsoletus, could then transmit these viruses across much wider areas of Europe. The fact that adult C. pulicaris are present in high abundances in winter may provide a mechanism by which these viruses can overwinter in these areas. 相似文献
88.
Genetic relationship between Mongolian and Norwegian horses? 总被引:3,自引:0,他引:3
Human populations of Central Asian origin have contributed genetic material to northern European populations. It is likely that migrating humans carried livestock to ensure food and ease transportation. Thus, eastern genes could also have dispersed to northern European livestock populations. Using microsatellite data, we here report that the essentially different genetic distances DA and (deltamu)2 and their corresponding phylogenetic trees show close associations between the Mongolian native horse and northern European horse breeds. The genetic distances between the northern European breeds and Standardbred/Thoroughbred, representing a southern-derived source of horses, were notably larger. We suggest that contribution of genetic material from eastern horses to northern European populations is likely to have occurred. 相似文献
89.
Di Berardino MA McKinnell RG Wolf DP 《Differentiation; research in biological diversity》2003,71(7):398-401
May 2002 marked the golden anniversary of the first cloned tadpoles. We celebrate this anniversary, as nuclear transplantation of frog cells into enucleated eggs became the prototype for cloning insects, fish, and mammals. We briefly review the salient results from amphibian cloning. Extension of these studies to mammalian species led to cloning adult cells, important advances in understanding nuclear reprogramming, and the construction of transgenic clones for biomedical applications. In addition, murine cloning clarified two problems unresolved in frog cloning: the unequivocal demonstration that nuclei of fully differentiated cells can direct the formation of fertile adults, and that abnormal expression of genes was responsible for the endoderm and neural syndromes in Rana clones. 相似文献
90.
Composite and clinal distribution of Glycine soja in Japan revealed by RFLP analysis of mitochondrial DNA 总被引:4,自引:0,他引:4
A. Tozuka H. Fukushi T. Hirata M. Ohara A. Kanazawa T. Mikami J. Abe Y. Shimamoto 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(2):170-176
Wild soybean (Glycine soja Sieb. et Zucc.), regarded as the progenitor of cultivated soybean [G. max (L.) Merr.], is widely distributed in East Asia. We have collected 1097 G. soja plants from all over Japan and analyzed restriction fragment length polymorphisms (RFLPs) of mitochondrial DNA (mtDNA) in
them. Based on the RFLPs detected by gel-blot analysis, using coxII and atp6 as probes, the collected plants were divided into 18 groups. Five mtDNA types accounted for 94% of the plants examined. The
geographic distribution of mtDNA types revealed that, in many regions, wild soybeans grown in Japan consisted of a mixture
of plants with different types of mtDNA, occasionally even within sites. Some of the mtDNA types showed marked geographic
clines among the regions. Additionally, some wild soybeans possessed mtDNA types that were identical to those widely detected
in cultivated soybeans. Our results suggest that the analysis of mtDNA could resolve the maternal lineage among plants of
the genus Glycine subgenus Soja.
Received: 16 June 1997/Accepted: 5 August 1997 相似文献