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711.
712.
A comparison of the actual vascular flora of the Tiber in Rome with a similar floristic survey of the 1970s was carried out.
Changes in species richness, floristic composition and structure occurred in the last 30 years were described and dynamics
of abundance of each species was estimated. The total number of species decreased from 604 in 1975–1981 to 501 till date.
The composition of the Tiber flora has partially changed. There has been a decrease in therophytes on the riverbed and an
increase in hydrophytes especially eutrophic ones. Most of Mediterranean species and those associated with undisturbed land
have been replaced by widely distributed, ruderal and alien species, as human influences have increased. The floristic variations
were used as indicator to evaluate the effect of human impact on the development of site and to describe the main changes
in river management and bank use occurred locally over the last decades. 相似文献
713.
714.
Almanza-Alcalde Horacio Satyal Poshendra Corbera Esteve SotoSánchez Alma Patricia Pskowski Martha 《Human ecology: an interdisciplinary journal》2022,50(1):79-90
Human Ecology - Since 2007 many developing countries have laid groundwork for Reducing Emissions from Deforestation and forest Degradation and sustainable management and conservation of forests... 相似文献
715.
Xuefeng Chen Hengyao Niu Yang Yu Jingjing Wang Shuangyi Zhu Jianjie Zhou Alma Papusha Dandan Cui Xuewen Pan Youngho Kwon Patrick Sung Grzegorz Ira 《Nucleic acids research》2016,44(6):2742-2753
DNA double-strand breaks (DSBs) are one of the most cytotoxic types of DNA lesion challenging genome integrity. The activity of cyclin-dependent kinase Cdk1 is essential for DSB repair by homologous recombination and for DNA damage signaling. Here we identify the Fun30 chromatin remodeler as a new target of Cdk1. Fun30 is phosphorylated by Cdk1 on Serine 28 to stimulate its functions in DNA damage response including resection of DSB ends. Importantly, Cdk1-dependent phosphorylation of Fun30-S28 increases upon DNA damage and requires the recruitment of Fun30 to DSBs, suggesting that phosphorylation increases in situ at the DNA damage. Consistently, we find that Cdk1 and multiple cyclins become highly enriched at DSBs and that the recruitment of Cdk1 and cyclins Clb2 and Clb5 ensures optimal Fun30 phosphorylation and checkpoint activation. We propose that the enrichment of Cdk1-cyclin complexes at DSBs serves as a mechanism for enhanced targeting and modulating of the activity of DNA damage response proteins. 相似文献
716.
The changes in germination and seed reserve composition that occur while seeds are stored in the laboratory or buried in the soil are important for understanding the potential and ecological longevity of seeds as well as seed-bank dynamics. Both germination and seed-bank dynamics depend on water availability. We studied 18 tree species, including those with permeable or impermeable seeds, from a tropical deciduous forest in Mexico. We measured seed germination in a growth chamber after (1) dispersal, (2) laboratory storage, (3) seed burial at two field sites and directly in the field, and (4) two rainy seasons. Lipids, nitrogen, and nonstructural carbohydrates were quantified after dispersal and after laboratory or field storage. Sixteen species were viable after three periods of laboratory storage (~3 years). Eleven species were viable after two burial periods in the field (~2 years). Nitrogen concentration decreased after storage and burial in 11 species. Species lipid concentration had a negative relationship with species water content at dispersal and after one burial period, whereas nonstructural carbohydrates showed the opposite trend. Potential and ecological longevities were similar in impermeable seeds. Most of the species studied can form persistent seed banks consisting mainly of species with impermeable seeds that can remain in the soil without degrading their viability. Germination in the field is staggered following natural precipitation pulses as a strategy to stagger seedling recruitment, which may insure against unfavorable conditions. 相似文献
717.
Morales-Mulia Sandra Magdaleno-Madrigal Víctor Manuel Nicolini Humberto Genis-Mendoza Alma Morales-Mulia Marcela 《Molecular biology reports》2020,47(12):9689-9697
Molecular Biology Reports - Orexins-A (OrxA) and -B (OrxB) neuropeptides are synthesized by a group of neurons located in the lateral hypothalamus and adjacent perifornical area, which send their... 相似文献
718.
Seed priming: state of the art and new perspectives 总被引:2,自引:0,他引:2
S. Paparella S. S. Araújo G. Rossi M. Wijayasinghe D. Carbonera Alma Balestrazzi 《Plant cell reports》2015,34(8):1281-1293
719.
Alejandro Estrada Rosamond Coates-Estrada Carlos Vasquez-Yanes Alma Orozco-Segovia 《American journal of primatology》1984,7(1):3-13
Information on the fruit diets of howling monkeys and fruit-eating bats in the tropical rain forest of Los Tuxtlas, Mexico was collected for a year to compare the plant species used. Howling monkeys used 19 plant species whereas bats used 32 plant species as fruit sources. Eleven species were common in the diet of both mammals. A rank analysis at the plant species level showed that the fruit diets of Alouatta and Artibeus were very different. In contrast to bats, howling monkeys displayed a seasonal pattern in fruit consumption. Diet overlap between the two mammals was highest during the monkeys' fruit-eating season. Measures of fruit production in eight trees (four species) indicated marked variations in fruit biomass produced and in length of fruiting from tree to tree and species to species. Peaks in fruit production were typical both at the species and the individual tree levels, demonstrating the very patchy nature of the fruit available to the monkeys and the bats. 相似文献
720.