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21.
I. Papastylianou 《Plant and Soil》1987,104(1):23-29
The increasing need for protein at low cost has created a need to evaluate the biological nitrogen fixing potential of legumes
in Cyprus. In field studies which were conducted over the growing years of 1982–3 and 1983–4, legumes which are traditionally
grown in the country were evaluated for dry matter and nitrogen yield and biological nitrogen fixation (BNF). The legumes
studied were medic (Medicago truncatula Gearth), ochrus vetch (Lathyrus ochrus L.), bitter vetch (Vicia ervilia L.) and faba bean (Vicia faba L. var major) in the first year and in addition chickpea (Cicer arietinum L.), woollypod vetch (Vicia dasycarpa Ten.) and tickbean (Vicia faba L. var minor) in the second year.
Using the A-value method with barley and oats as reference crops, nitrogen (N) fixed by the various legumes in the first year
was 30–50% and from 55–67% of total N yield for the two reference crops, respectively. In the second year the estimates of
N fixed ranged from 70 to 80% with similar results obtained for the two reference crops barley and ryegrass. However, in the
second year chickpea, which had limited nodulation, fixed only 40% of its N yield.
Estimates of nitrogen from the atmosphere (Ndfa) obtained by the difference method (DM) were 10 to 14% lower than those from
the A-value method. These results were obtained after correcting for the amount of N derived from the applied fertilizer.
The two methods were highly correlated (r=0.98) for estimates of amount of BNF. The rates of N2 fixation of uninoculated legumes which are nodulated by the indigenous populations of Rhizobium in Cyprus are comparable
to those of legumes inoculated with selected strains of Rhizobium in other countries. An exception was the amount of N fixed
by chickpea. The appearance of the first nodules at late stages of growth may be the reason for the low BNF of this crop. 相似文献
22.
G. R. Findenegg 《Plant and Soil》1987,103(2):239-243
Seedlings of 14 species were grown for 14–28 days on nutrient solution with 6 mmol.l−1 NH4 as the sole nitrogen source. Solutions acidity was were kept constant at pH 4.0, 5.0, 6.0 and 7.0 by continuous titration
with diluted KOH. The following species were used: barley, maize, oats sorghum, yellow and white lupin, pea, soybean, carrot,
flax, castor-oil, spinach, sugarbeet and sunflower. Most plant species grew optimally at pH 6.0 with slight reductions at
pH 5.0. Growth of many species was severely inhibited at pH 4.0, but this inhibition was not observed with the legume and
cereal species. Yield depressions at pH 4.0 relative to pH 6.0 were well correlated with the respective relative decreases
of the K concentration in their roots (P<0.002). In the roots of two species (sunflower and flax) total N concentrations were also strongly reduced at pH 4.0. apparently,
the interactions between uptake of K, NH4 and H ions become the prevalent problem at suboptimal pH. At pH 7.0, yields were also considerably decreased, with the exception
of the lupines. At this pH, the roots of the growth inhibited plants were characterized by increased levels of total N and
free NH4. It is thought that the binding capacity of the roots for NH4 is an important factor in preventing NH4/NH3 toxicity at supraoptimal pH. 相似文献
23.
Alvaro García-Tejedor A. Raul Castaño Federico Morán Francisco Montero 《Journal of molecular evolution》1987,26(4):294-300
Summary The most relevant properties of hypercycles were previously studied mainly from a theoretical point of view. We have developed a Monte Carlo method simulating hypercyclic organization to obtain information about the dynamics of this prebiotic organization. Nucleation, growth, and selective properties have been tested and the results obtained are in good agreement with those of the theoretical predictions. The influence of hypercyclic organization of the error threshold has also been studied. As a consequence of the emergence of a hypercycle, the value of this threshold decreases. The amount of this decrease depends on the population size. Moreover, for some interval of quality factor values, either the hypercycle organization or an error catastrophe can be produced, depending on the initial conditions. The influence of these phenomena on both the dynamic behavior and evolutionary advantages of the hypercycle, as well as their decisive roles on genome size, are discussed.Presented at the FEBS Symposium on Genome Organization and Evolution, held in Crete, Greece, September 1–5, 1986 相似文献
24.
G. Modiano G. Cermele C. Santolamazza S. Biagioni G. Scarsella L. E. Pacifici G. Toschi 《International Journal of Anthropology》1987,2(1):61-73
392 random patients treated with SCC prior to surgery were assayed for pseudocholinesterase activity and electrophoretic pattern.
The estimate of the percent frequencies of theE
1
a
allele were 1.16±0.38 and of the C5 (+) phenotype 9.7±1.5, both typical of Caucasian populations. By combining the presentE
1
a
gene frequency estimate with that from another sample of the same population (Cermele
et al., 1987) a better estimate with smaller confidence limits was obtained, that is: 1,14±0,27. One subject interpreted asE
1
a
E
1
a
on phenotypic grounds was also found (expected 0,05) in this random sample.
A correlation coefficient of −0.521 was found between E activity and myorelaxation time in the whole sample. High correlation
values (r=−0.55 and r=−0.46) were found forE
1
u
E
1
u
; C5 (−) andE
1
u
E
1
u
; C5 (+) individuals, respectively, showing a strong dependence of the latter variable on the former one even within apparently
homogeneous classes. The use of the product of these two variables as a classification criterion allowed the identification
of a subject with very long myorelaxation time but normal activity. 相似文献
25.
Yeast submitochondrial particles, in a Pi- and NADH-dependent reaction, produced low concentrations of free ATP in the absence of added ADP. This formation of free ATP, as measured by the luciferin-luciferase method, was strongly stimulated by oligomycin. For maximal stimulation, oligomycin was to be added not earlier than 5–10 min after the addition of NADH. Upon addition of antimycin or FCCP the system was completely inhibited. The amount of free ATP formed corresponded to one-third of the amount of bound ATP in submitochondrial particles. The stimulatory effect of oligomycin disappeared if the submitochondrial particles were spun down after oligomycin stimulation and then resuspended in the reaction medium, whereas submitochondrial particles with no oligomycin added initially were stimulated by oligomycin after the same procedure. A different picture emerged with addition of ADP. If the submitochondrial particles were preenergized with NADH in the presence of oligomycin before the addition of ADP the formation of free ATP upon subsequent addition of ADP was inhibited by oligomycin. In the presence of oligomycin, but lacking preenergization with NADH, a stimulation of free ATP formation was achieved with added ADP. A possible explanation for the stimulating effect of oligomycin on ATP formation in the absence of added ADP is that it enhances the release of bound ATP in an energy-requiring process. The release of only about one-third of the bound ATP could indicate that one of three nucleotide-binding subunits involved in the mechanism of ATP formation by ATP synthase is in a state suitable for such an energy-dependent release of ATP. 相似文献
26.
27.
The changes of dominance rank among female Japanese monkeys of the Koshima group over a period of 29 years from 1957 were
studied. The dominance rank order was relatively stable in the early population growing phase, while large scale-changes of
dominance rank order occurred successively in the phase of population decrease brought about by the severe control of artificial
feeding after 1972. Nevertheless, the rank order of several females of the highest status was stable. Furthermore, the reproductive
success of these highest status females was high (Mori, 1979a;Watanabe et al., in prep.). Divergence of the dominance rank order fromKawamura's rules (Kawamura, 1958) was observed in the following respects: (1) Some females significantly elevated their rank depending on the leader
males. (2) If mothers died when their daughters were still juveniles or nulliparous, the dominance rank of some of these offspring
females was significantly lower than the mother's one. However 55% of daughters which lost their mothers at a young age inherited
the mother's rank. (3) Dominance among sisters whose mother had died when at least one of the daughters was under 6 years
old followed the rule of youngest ascendancy in 60% (Kawamura, 1958), and in 80% when both of the daughters were nulliparous at the mother's death.
The mean rate of aggressive interactions for each female with subordinates to her was calculated by dividing the total aggressive
interactions between the female in question and her subordinates by the number of subordinate females to the female in question.
A female which showed a high rate of aggressive interactions with her subordinates was categorized as an “Attacker”, and a
female showing a lower rate was categorized as a “Non-attacker”. Similarly, categories of “Attacked”, and “Non-attacked” were
distinguished by using the rate of aggressive interactions with dominant females. Several females which were once categorized
in one category in a year were repeatedly categorized in the same category over different years. The “Attacked” tended to
be females of higher rank, and “Non-attackers” tended to be females of lower rank. “The second-higher-status females”, were
“Attacked”, and their rank was unstable. In particular, females of lower rank within the lineage of the highest rank suffered
this kind of severe status. Most of the daughters of these females showed a sharp drop of rank, and died when they were still
at a young age, i.e. “the second-higher-status females” displayed low fitness. “Non-attackers” were significantly “Non-attacked”;
i.e. they were females which showed a non-social attitude. Females which underwent a drop of rank tended to be “Non-attackers”.
The most important factor which determined the females' rank was the memory of their dominance relations under the influence
of their mother [dependent rank (Kawai, 1958)] in their early life during development. This finding corresponds well with the results in baboons obtained byWalter (1980); the target females of aggressive interactions by adolescent females were determined by the rank of the mothers when
these adolescent females were born. 相似文献
28.
Chuen-Shang C. Wu Junichi Hasegawa Andrew P. Smith Horace H. Loh Nancy M. Lee Jen Tsi Yang 《Journal of Protein Chemistry》1990,9(1):3-7
Based on circular dichroism (CD) and the sequence-predictive method, the opioid-binding cell adhesion molecule (OBCAM) consisted of one half -sheets and one fourth -helices. This is consistent with significant sequence homology of the protein to several members of the immunoglobulin (Ig) superfamily, particularly cell adhesion molecules, which are rich in -sheets. Hydropathy analysis suggests that hydrophobic and hydrophilic regions were evenly distributed along the sequence, but the NH2- and COOH-termini were hydrophobic. Hydrophobic moments and Fourier-transform amphipathic analyses further suggest that residues 23–30 and 83–93 were amphiphathie -sheets. The overall conformation of OBCAM was unaltered by adding linoleic acid, which is required for opioid ligand binding. 相似文献
29.
Dr. Kenjiro Wake Kiyoyuki Motomatsu Chieko Dan Kenji Kaneda 《Cell and tissue research》1988,253(3):563-571
Summary The three-dimensional structure of endothelial cells in the hepatic sinusoids of the rat was studied by application of light- and electron microscopy on Golgi-impregnated specimens. A number of endothelial cells could thus be individually delineated throughout the hepatic lobules. The cytoplasm, showing heavy silver deposits, consists of two distinct areas, a thick and thin portion. The thick portion, issuing from the region of the perikaryon, branches and tapers toward the cell periphery. The thin portion, occupying the remainder of the cytoplasm, consists largely of highly fenestrated sieve plates. Some intralobular variation can be noted; the thick portion of the endothelial cells is well developed in the periportal zone, while the cells in the centrilobular zone are relatively rich in thin portions. In addition, the area of distribution of an individual endothelial cell is larger in the centrilobular sinusoids than in the periportal zone. Some endothelial cells also possess unique cytoplasmic processes projecting into the intercellular space between hepatocytes and connecting the sinusoidal walls of neighboring sinusoids. These processes may anchor the endothelial cells to the hepatic plates. 相似文献
30.