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Forbs are important biodiversity components of grasslands and are often threatened by management intensification. As most forbs propagate predominantly by seed, knowledge of their seed regenerative traits would improve the conservation and restoration of forb-rich ecosystems. The main seed production traits of six forbs that are common in European species-rich grasslands were studied by collecting fertile shoots from different sites and over several years. Among sites and years, variability was high, particularly in the number of inflorescences per shoot, which affected ovule production more than any other trait. Relationships between inflorescence size and the number of ovules were mainly negatively allometric or almost so, with lower flower densities in larger inflorescences. The average ovule-to-seed transformation efficiency was 58%. There was significant variation among collections of the same species, and even more between species. Species with a low ovule-to-seed transformation efficiency generally exhibited compensatory, high seed viability. Large inflorescences had high ovule to seed utilization values, probably because of better nutrient conditions. Seed germinability (average, 30%) was much lower than seed viability (average, 54%); therefore, seed dormancy was an important feature of the species studied. 相似文献
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Giulia Schiroli Anastasia Conti Samuele Ferrari Lucrezia della Volpe Aurelien Jacob Luisa Albano Stefano Beretta Andrea Calabria Valentina Vavassori Patrizia Gasparini Eralda Salataj Delphine Ndiaye-Lobry Chiara Brombin Julie Chaumeil Eugenio Montini Ivan Merelli Pietro Genovese Luigi Naldini Raffaella Di Micco 《Cell Stem Cell》2019,24(4):551-565.e8
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Moeller R Horejsi R Pilz S Lang N Sargsyan K Dimitrova R Tafeit E Giuliani A Almer G Mangge H 《Obesity (Silver Spring, Md.)》2007,15(5):1319-1324
Objective: To compare subcutaneous adipose tissue topography (SAT‐top) in obese juveniles with age‐matched normal‐weight controls. Research Methods and Procedures: The optical device LIPOMETER (European Patent EP 0516251) enables the non‐invasive, rapid, safe, and precise measurement of the thickness of subcutaneous adipose tissue. Fifteen defined body sites (1 = neck to 15 = calf) characterize the individual SAT‐top like an individual fingerprint. SAT‐top of 1351 juveniles (obese: 42 boys, 59 girls, normal weight: 680 boys, 570 girls) from 7 to 19 years of age were measured. For visual comparison, the 15‐dimensional SAT‐top information was condensed by factor analysis into a two‐dimensional factor plot. Results: Both female and male obese juveniles had markedly increased adipose tissue layers at 7 = upper abdomen, 8 = lower abdomen, 5 = front chest, and 6 = lateral chest. The pubertal changes of body shape and fat distribution of the normal‐weight boys and girls (boys show thinner adipose tissue layers on their legs, whereas girls had thicker adipose tissue layers at the extremities) were not seen in the obese group. Independently of age and sex, all of the obese juveniles showed a similar, more android body fat distribution with increased trunk fat. Discussion: SAT‐top of the obese juveniles is similar to that of patients with type 2 diabetes, polycystic ovary syndrome, and coronary heart disease. Patients with these metabolic disorders and obese juveniles are located in the factor plot in the same area. This body shape may indicate a risk profile for developing polycystic ovary syndrome (women), type 2 diabetes, and early atherosclerosis (both sexes). 相似文献
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Biodeterioration of crude oil and oil derived products: a review 总被引:2,自引:0,他引:2
Natalia A. Yemashova Valentina P. Murygina Dmitry V. Zhukov Arpenik A. Zakharyantz Marina A. Gladchenko Vasu Appanna Sergey V. Kalyuzhnyi 《Reviews in Environmental Science and Biotechnology》2007,6(4):315-337
Biodeterioration of crude oil and oil fuels is a serious economic and an environmental problem all over the world. It is impossible
to prevent penetration of microorganisms in oil and fuels both stored in tanks or in oilfields after drilling. Both aerobic
and anaerobic microorganisms tend to colonise oil pipelines and oil and fuel storage installations. Complex microbial communities
consisting of both hydrocarbon oxidizing microorganisms and bacteria using the metabolites of the former form an ecological
niche where they thrive. The accumulation of water at the bottom of storage tanks and in oil pipelines is a primary prerequisite
for development of microorganisms in fuels and oil and their subsequent biological fouling. Ability of microorganisms to grow
both in a water phase and on inter-phase of water/hydrocarbon as well as the generation of products of their metabolism worsen
the physical and chemical properties of oils and fuels. This activity also increases the amount of suspended solids, leads
to the formation of slimes and creates a variety of operational problems. Nowadays various test-systems are utilized for microbial
monitoring in crude oils and fuels; thus allowing an express determination of both the species and the quantities of microorganisms
present. To suppress microbial growth in oils and fuels, both physico-mechanical and chemical methods are applied. Among chemical
methods, the preference is given to substances such as biocides, additives, the anti-freezing agents etc that do not deteriorate
the quality of oil and fuels and are environmentally friendly. This review is devoted to the analysis of the present knowledge
in the field of microbial fouling of crude oils and oil products. The methods utilized for monitoring of microbial contamination
and prevention of their undesirable activities are also evaluated. The special focus is given to Russian scientific literature
devoted to crude oil and oil products biodeterioration. 相似文献
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