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N. Y. Yalcin-Mendia M. Ipek H. Kacan S. Curuk N. Sari S. Cetiner V. Gaba 《Journal of plant biochemistry and biotechnology.》2003,12(2):147-150
The optimization of regeneration protocol for different genotypes increases the yield in transformation studies. Cotyledon explants of watermelon [Citrullus lanatus (Thunb) Matsum & Nakai] cv Crimson Sweet were cultured on MS medium containing combinations of benzyl adenine (BA) (0, 5, 10, 20 µM) and indole-3-acetic acid (IAA) (0, 0.5, 5 µM). Maximum shoot growth and subsequent rooting from explants on regeneration medium were obtained from the media containing 10 µM BA + 0.5 µM IAA and 20 µM BA (75 and 78%) by direct organogenesis, respectively. Histological analysis showed that cell division was observed in the epidermal and subepidermal layers. Protuberant structures were observed in tissues between 7 and 12 days in culture. Meristematic structures were observed after 12days in culture which later developed into buds. 相似文献
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M. R. Sarić 《Plant and Soil》1987,99(1):197-209
Summary The paper discusses the problems of genetic aspects of plant mineral nutrition in the light of the results presented at the
First and Second Symposia on ‘Genetic Aspects of Plant Mineral Nutrition’ organized in Beograd in 1982 and Madison in 1985,
respectively. On the basis of the results, future directions of research are discussed. The papers deal with the concentration
and content of mineral nutrients in different genotypes, physiological and biochemical aspects of the genetic specificity
of plant mineral nutrition, relations between plant genotypes and nitrogen fixing micro-organism strains, as well as with
some related problems which have been investigated to a lesser extent. Particular attention is paid to papers and problems
referring to genetic and breeding research work linked with genetic aspects of plant mineral nutrition as well as the possibilities
of developing new cultivars requiring certain soil and mineral nutrition conditions for their cultivation. 相似文献
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Predator-induced phenotypic plasticity in Daphnia pulex: uncoupling morphological defenses and life history shifts 总被引:1,自引:1,他引:0
Chemical cues from a predator Chaoborus sp. induce morphological defense (neck spine) and life history shifts (later reproduction, decreased fecundity but larger juvenile size) in the waterflea Daphnia pulex. These shifts have been interpreted either as costs of defense or as separate adaptation. In order to investigate if the life history shifts can be separated from the morphological defense, Daphnia pulex individuals were exposed to chemical cues from Chaoborus at different stages of life for variable periods. The daphnids that were exposed to Chaoborus started their reproduction later than the controls, although the differences were not statistically significant. Neck spine was induced only if daphnids were exposed to Chaoborus in an early stage of their life. Numbers of eggs produced were not affected by the different treatments, but egg mortality was higher in mothers exposed to Chaoborus. With these treatments it was possible to see neck spine induction without measurable life history changes or costs. On the other hand, irrespective of neck spine presence, the Chaoborus chemical(s) had an effect on Daphnia pulex mothers.Publication no 2159. Netherlands Institute of Ecology, Centre for LimnologyPublication no 2159. Netherlands Institute of Ecology, Centre for Limnology 相似文献
7.
Hanna Ebeling Tuulikki Porkka Varpu Penninkilampi-Kerola Eija Berg Sari J?rvi Irma Moilanen 《Twin research》2003,6(4):334-343
We evaluated dominance-submissiveness between co-twins and its relationship to mental health in a cohort study of 419 twins followed from pregnancy to 22-30 years of age. Dominance-submissiveness between co-twins was assessed from three separate perspectives: physical dominance, psychological dominance, and verbal dominance. Depressive, nervous, and psychosomatic symptoms were analyzed in different twin groups. In the physical domain, males were more commonly dominant than females at school age and in adulthood. Before and at school age, girls were more dominant than boys in the psychological and verbal domains, as well as in total dominance. These differences disappeared in adulthood, and 81% of adult twins felt themselves equal to their co-twin in total dominance. Submissiveness in the psychological domain seemed to be associated with increased depressiveness, nervous complaints and psychosomatic symptoms in males of male-female twin pairs. Verbally submissive males in same-sex twin pairs had more depression and psychosomatic symptoms. Among females of same-sex twin pairs, submissiveness in the psychological domain was most clearly associated with depressive symptoms, whereas psychological or verbal dominance-submissiveness among females from male-female twin pairs was not associated with symptoms. Psychologically dominant males and females of same-sex twin pairs expressed greater nervousness than did their co-twins. We conclude that being submissive, especially in the psychological domain, to a female twin partner seems to be stressful, whereas it is easier, especially for females, to be submissive to a male twin partner. 相似文献
8.
The effects of aluminium chloride (AICI3) treatments (50 and 150 mg/l) on 3-year-old Scots pine (Pinus sylvestris L.) seedlings were studied in a sand culture during 2 growing periods in an open field experiment. Even by the end of the
first growing period, a decline was observed in the concentrations of Ca, Mg and P within the needles, and of Ca and Mg in
the roots. After the second growing period, increased N and K concentrations were observed in the needles of Al-treated seedlings.
Both the needles and roots of Al-treated seedlings showed, after the second growing period, a decline in growth and increased
concentrations of AI as the amount of AICI3 in the nutrient solution increased. Al-induced changes in needle structure were
found to be symptomatic of a nutrient imbalance, particularly of Mg and P. Al-stress did not result in any observable changes
in root anatomy or in the number of mycorrhizas. Scots pine proved to be rather resistant to Al-stress, indicating that direct
Al-injuries are not likely in the field, though Al-stress may be a contributing factor in the formation of nutrient imbalances. 相似文献
9.
In the presence of acetyl phosphate, approximately 0.8 extra sulphydryl groups/105 g protein of sarcoplasmic reticulum membrane vesicles are exposed to reaction with -ethylmaleimide, whereas in the presence of ATP approximately 0.6 groups/105 g protein are protected. Dithiobis (nitrobenzoic acid) reacts with the membrane sulphydryl groups more slowly in the presence of ATP than in the presence of acetyl phosphate or in the absence of substrate. Sarcoplasmic reticulum membrane is degraded by trypsin at a faster rate than normal when acetyl phosphate is present as seen from changes in electrophoretic patterns, ATPase activity and Ca2+ uptake capacity, and at a slower rate when ATP is present as seen from the last two properties. These differences in reactivity are interpreted as being due to differences in membrane conformations induced by the two substrates. 相似文献
10.
M. Sari Gorla E. Rovida 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1980,57(1):37-41
Summary Intergametophytic influences on pollen competitive ability were studied by means of the pollen mixture technique: mixtures of pollen from different genetic sources, marked for the presence of the normal or the mutant allele of the opaque-2 gene, were used to pollinate o2o2 female plants. The variation of relative frequency of one of the two kernel types from apex to base of the resulting ear, made it possible to measure the competitive ability by regression coefficients.The effect of the pollen marker on the character was estimated by analyzing the progeny of heterozygous o2/+ plants self-pollinated through four generations. The o2 allele-bearing pollen revealed a slower germination rate than the dominant counterpart; no differences between the two pollen types were observed with regard to tube growth rate.The occurrence of intergametophytic interactions was confirmed: the competitive ability of a line varied according to the genotype of the competing pollen. Thus, this component has to be taken into account in considering male gametophyte fertilization ability. 相似文献