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Yuzuru Hamada Toshifumi Udono Migaku Teramoto Ikuo Hayasaka 《Primates; journal of primatology》1998,39(2):157-169
Skeletal developmental of chimpanzees was studied cross-sectionally. By application of the TW2 method, we described the skeletal
development of chimpanzees and compared their skeletal development with humans'. A development pattern of chimpanzees repeated
accelerations and decelerations displaying “early-juvenile trough,” “pre-adolescent peak,” “mid-adolescent trough,” and “post-adolescent
peak” in incremental curves. Sex differences in skeletal development are slower development in males during infant and early
juvenile phases, and greater increment around the adolescent phase in males. Females are fully mature at younger ages than
males, e.g. about one and a half years. In comparison with chimpanzees, humans have such characteristics as a longer slower
period of juvenile development and a shorter spurt-like adolescent fast period which ends with full maturity. 相似文献
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Egg predation by conspecific males of damselfishes,Pomacentrus nagasakiensis andChromis notatus notatus, was studied at Bohnotsu (31°15′ N, 131°15′ E) and Tsuyazaki (33°47′ N, 130°29′ E), respectively. InP. nagasakiensis, 7 egg-guarding males were removed from nests, and intrusion and egg predation by conspecific males took place in all of
the nests within an average time of 12.2 min. Frequency of attacks on eggs by other reef fishes during the period between
the removal of egg-guarding males and intrusion of conspecific males was lower than expected, considering the frequency of
aggressive displays of the egg-guarding males. The results of male removal experiments forChromis notatus notatus were almost the same, with intrusion and egg predation by conspecific males occurring in all 12 of the nests from which egg-guarding
males had been removed. SixP. nagasakiensis and 15C. notatus notatus which intruded into the nests and preyed on eggs were collected. All were males except for 1C. notatus notatus female. Results suggest that these males which intruded into vacant nests to eat eggs did not have clutches of their own
during the spawning bouts when the experiments were done. Results also showed that the intruding males were not inferior to
egg-guarding males in standard length, gonadosomatic index, and condition factor. It is clear that males which do not have
their own clutches during at least 1 spawning bout and prey on others' eggs when egg-guarding males disappear are common in
these 2 gregariously nesting damselfishes. It is discussed that conspecific eggs are potentially a good food source not only
for other species of reef fishes but also for conspecific males which do not have their own eggs during the spawning bouts.
The origin of males wich prey on eggs of other conspecifics is also considered. Some aspects of egg-guarding and aggressive
behavior of males in damselfishes are discussed. 相似文献
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We present conclusive evidence for the chromosomal location of the lac gene in a lactose-fermenting Salmonella litchfield strain (AO Lac+). Two Hfr strains constructed from AO Lac+ had abilities to transfer the lac gene to S. typhimurium LT2 at relatively high frequencies. Detailed characterization of the transconjugants suggested that the lac in AO Lac+ was located on the host chromosome between galE (18 min) and trpB (34 min). Transduction experiments using P22 phage showed that the lac was cotransduced with gal, but not with trpB. These results clearly indicate that the lac gene is located at a position near 18 min of the linkage map of Salmonella. 相似文献
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Immune spleen cells (ISC) capable of inhibiting the growth of adenovirus type 12 (Ad12) tumors were raised in C57BL/6 mice by immunization with Ad12, fractionated according to their affinity for plastic and nylon-wool substrates or treated with various antisera plus complement, and subjected to the tumor-neutralization test (Winn) to define the effector cells for the cell species. Full antitumor activity of ISC was recovered in the cell fractions nonadherent to the two substrates; the antitumor activity of ISC was abrogated entirely by anti-Thy-1,2 serum and almost entirely by anti-Lyt-2.2 ascites fluid plus complement. These results clearly indicate that T-lymphocytes, particularly those bearing Lyt-2.2 antigen, are the principal effectors in ISC against Ad12 tumors in animals. 相似文献
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Retardation of bone development was observed in the Koshima troop of free ranging Japanese macaques. In the control group,
epiphyseal unions of appendicular long bones generally started to close at about 4 yrs of age and were completed at about
8 or 9 yrs of age. Limb bone unions of the Koshima troop, however, started to close at about 9 yrs of age and completely closed
at about 15 yrs of age. In the epiphyseal unions of trunk and girdle bones, the Koshima troop again showed a retardation of
closure compared with the control group. Until long bones reached their full length, that is, until about 15 yrs of age, their
size was small in the Koshima troop compared with the control group, though the sample size of the Koshima troop was small.
After 15 yrs of age, however, many osteometrical measurements of the Koshima troop were nearly the same as controls. A prolonged
growing duration compensated for the slow growth and allowed them to become as large as controls. This prolongation may be
an adaptation in response to small size during the developmental period.
In some parts of the body, however, Koshima macaques failed to reach the adult size of controls. Males were less likely than
females to reach full size. Causes of the retardation and small size in the Koshima troop are discussed, but they remain open
to further studies. 相似文献