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141.
Alejandro Nettel Richard S. Dodd Jorge A. Cid-Becerra Jorge de la Rosa-Velez 《Conservation Genetics》2008,9(4):1037-1038
We developed nine new microsatellite markers for the white mangrove (Laguncularia racemosa C.F. Gaertn.), a mangrove species widely distributed in the Western Hemisphere. The loci were developed from a sample collected
in Baja California Sur, Mexico, and were screened for polymorphism in 108 individuals from the Pacific Coast of Mexico and
Costa Rica. The level of polymorphism was relatively low, from two to four alleles. These are the first set of polymorphic
markers described for L. racemosa and should be of value in studying regional genetic differentiation among natural populations of this species. 相似文献
142.
143.
J. P. Busogoro L. Masquellier J. Kummert O. Dutrecq P. Lepoivre M. H. Jijakli 《Journal of Phytopathology》2008,156(7-8):452-457
Samples of cassava leaves exhibiting severe symptoms of cassava mosaic disease (CMD) were collected with the PhytoPASS kit in fields surrounding the city of Bujumbura (Burundi). These materials were then sent to Belgium for polymerase chain reaction determination of the CMD begomoviruses inducing the observed symptoms. Different pairs of specific primers were used to amplify DNA sequences specific to African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV), East African cassava mosaic Cameroon virus (EACMCV), East African cassava mosaic Malawi virus (EACMMV), East African cassava mosaic Zanzibar virus (EACMZV), the Uganda variant of East African cassava mosaic virus (EACMV-UG) and South African cassava mosaic virus (SACMV). It was revealed that mixed infections were prevailing in the analyzed materials. Most of the samples submitted to this analysis were found to be co-infected by three different begomoviruses (ACMV + EACMV + EACMV-UG). The so revealed mixed infections could explain the high severity of CMD symptoms noticed on cassava in the region of Bujumbura while the diversity within the CMD causal agents illustrates the importance to take this parameter into consideration for a successful use of plant genetic resistance to control the disease. 相似文献
144.
Philipp Wagner Jörn Köhler reas Schmitz Wolfgang Böhme 《Journal of Biogeography》2008,35(8):1349-1361
Aim The Kakamega Forest, western Kenya, has been biogeographically assigned to both lowland and montane forest biomes, or has even been considered to be unique. Most frequently it has been linked with the Guineo‐Congolian rain forest block. The present paper aims to test six alternative hypotheses of the zoogeographical relationships between this forest remnant and other African forests using reptiles as a model group. Reptiles are relatively slow dispersers, compared with flying organisms (Aves and Odonata) on which former hypotheses have been based, and may thus result in a more conservative biogeographical analysis. Location Kakamega Forest, Kenya, Sub‐Saharan Africa. Methods The reptile diversity of Kakamega Forest was evaluated by field surveys and data from literature resources. Faunal comparisons of Kakamega Forest with 16 other African forests were conducted by the use of the ‘coefficient of biogeographic resemblance’ using the reptile communities as zoogeographic indicators. Parsimony Analysis of Endemism and Neighbour Joining Analysis of Endemism were used to generate relationship trees based on an occurrence matrix with paup *. Results The analysis clearly supports the hypothesis that the Kakamega Forest is the easternmost fragment of the Guineo‐Congolian rain forest belt, and thus more closely related to the forests of that Central–West African complex than to any forest further east, such as the Kenyan coastal forests. Many Kenyan reptile species occur exclusively in the Kakamega Forest and its associated forest fragments. Main conclusions The Kakamega Forest is the only remnant of the Guineo‐Congolian rain forest in the general area. We assume that the low degree of resemblance identified for the Guineo‐Congolian forest and the East African coastal forest reflect the long history of isolation of the two forest types from each other. Kenyan coastal forests may have been historically connected through forest ‘bridges’ of the southern highlands with the Congo forest belt, allowing reptile species to migrate between them. The probability of a second ‘bridge’ located in the region of southern Tanzanian inselbergs is discussed. Although not particularly rich in reptile species, the area should be considered of high national priority for conservation measures. 相似文献
145.
146.
S. A. Limborska P. A. Slominsky S. D. Nurbaev E. V. Balanovskaya M. I. Shadrina S. N. Popova O. V. Belyaeva T. V. Pogoda O. P. Balanovsky D. A. Verbenko K. B. Bulaeva E. K. Khusnutdinova V. A. Spitsyn A. I. Mikulich 《Human Evolution》2004,19(3):203-215
Most of the population of Eastern Europe inhabit an area of great anthropological interest, because of the contact between
Caucasoid and Mongoloid anthropological types. We have analyzed normal variability in minisatellite and microsatellite loci
in some East European population. Different synthetic maps were constructed using reliability theory to evaluate the degree
of accuracy. Comparison of the synthetic maps for DNA with classical markers has revealed a high level of correlation. All
the data obtained show the diverse influence of both anthropological types in forming the gene pool of the Eastern European
peoples. 相似文献
147.
中国第四纪冰期与陆生脊椎动物残留分布 总被引:8,自引:0,他引:8
在第四纪冰期中 ,中国东部地区是否发生过冰川 ,长期存在争议。中国东部地区冰川说的创始人李四光教授在提出该学说时 ,从古生物方面未得到冰期生物群的证据。现存生物种的地理残留现象可反映地质历史时期的气候变化。本文作者依据中国陆生脊椎动物的北方残留、热带 -亚热带残留、温带湿润带残留等现象 ,推断 :(1)在冰期的冷期中喜暖动物南迁时 ,中国东部地区是一避难地 ;(2 )在中国东部地区未见有典型冰川残留种的存在 ;(3)一些湿润种的间断残留分布与中国北方黄土及干旱气候的发展有密切的关系。此结论似不支持中国东部冰川说 相似文献
148.
湖北峡东地区九龙湾剖面震旦系陡山沱组微体化石的新发现 总被引:3,自引:0,他引:3
中国南方扬子地台震旦系陡山沱组产出丰富的微体化石,它们主要保存在磷块岩以及燧石结核和条带中。文章详细报道湖北峡东地区九龙湾剖面震旦系陡山沱组微体化石,描述以前未曾在峡东地区碳酸盐相燧石中发现的8属8种微体化石。研究九龙湾剖面陡山沱组大型带刺疑源类、微体多细胞藻类和动物胚胎化石的分布特征,发现Tianzhushania spinosa是最早出现的大型带刺疑源类分子,大冰期后微体生物的辐射是一个阶段性渐进的过程。同时.本项研究进一步证实华南扬子区陡山沱组碳酸盐相燧石和磷块岩地层中保存的微体化石面貌基本一致。 相似文献
149.
The East Himalaya-Hengduan Mountains region is the center of diversity of the genus Primula, and P. sikkimensis is one of the most common members of the genus in the region. In this study, the genetic diversity and structure of P. sikkimensis populations in China were assessed using inter-simple sequence repeat (ISSR) and chloroplast microsatellite markers. The
254 individuals analyzed represented 13 populations. High levels of genetic diversity were revealed by ISSR markers. At the
species level, the expected heterozygosity and Shannon’s index were 0.4032 and 0.5576, respectively. AMOVA analysis showed
that 50.3% of the total genetic diversity was partitioned among populations. Three pairs of chloroplast microsatellite primers
tested yielded a total of 12 size variants and 15 chloroplast haplotypes. Strong cpDNA genetic differentiation (G
ST = 0.697) and evidence for phylogeographic structure were detected (N
ST = 0.788, significantly higher than G
ST). Estimated rates of pollen-mediated gene flow are approximately 27% greater than estimated rates of seed-mediated gene flow
in P. sikkimensis. Both seed and pollen dispersal, however, are limited, and gene flow among populations appears to be hindered by the patchiness
of the species’ habitats and their geographic isolation. These features may have played important roles in shaping the genetic
structure of P. sikkimensis. A minimum-spanning tree of chloroplast DNA haplotypes was constructed, and possible glacial refugia of P. sikkimensis were identified. 相似文献
150.
Oxygen consumption of East Siberian cod: no support for the metabolic cold adaptation theory 总被引:2,自引:0,他引:2
Standard metabolic rate ( R s ) at 2°C of eight East Siberian cod Arctogadus borisovi , caught in West Greenland, body mass of 601.5 ± 147.6 g (mean ± s.D.), was 40.9 ± 5.9 mg O2 kg-1 h-1 and 59.0 ± 6.6mg O2 kg-1 h-1 when extrapolated to a standardized 100 g fish. R s was compared with three other Gadidae, to test the theory of metabolic cold adaptation (MCA). There was no evidence of MCA in the family. 相似文献