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761.
762.
Mayuko Otsuki Tomonari Akamatsu Takahiro Nobetsu Yoko Mitani 《Marine Mammal Science》2021,37(4):1330-1340
UNESCO World Natural Heritage sites are established to ensure the long-term conservation of natural areas. Nemuro Strait in northern Japan is adjacent to the Shiretoko World Natural Heritage Site, and attracts various trophic levels of marine species, including marine mammals. Although the coexistence of humans and marine mammals is an important issue in this area, the temporal habitat use of cetaceans in this area is unknown. Here, we document seasonal and diel changes in cetacean vocalizations collected using passive acoustic recording devices during November 2012–March 2014. Killer whale calls occurred in spring and summer, and sperm whale clicks were detected in summer. Pacific white-sided dolphin calls were recorded in summer and late fall. No cetaceans were recorded during the sea ice period in February and March. The dolphin calls and unknown click trains were significantly more frequent at night. In contrast, marginal diel changes in killer whale calls were detected. Our results suggest that the majority of cetaceans utilize Nemuro Strait at night during the ice-free period, and we provide new insights into the habitat use and diversity of marine mammals in the Strait. 相似文献
763.
764.
Genetic characterization of late-flowering traits induced by DNA hypomethylation mutation in Arabidopsis thaliana 总被引:6,自引:2,他引:4
Tetsuji Kakutani 《The Plant journal : for cell and molecular biology》1997,12(6):1447-1451
Arabidopsis DNA hypomethylation mutation, ddm1 , results in a variety of developmental abnormalities by slowly inducing heritable lesions at unlinked loci. Here, late-flowering traits observed at high frequencies in independently-established ddm1 lines were genetically characterized. In all of the four late-flowering lines examined the traits were dominant and mapped to the same chromosomal region, which is close or possibly identical to the FWA locus. The ddm1 -induced phenotypic onsets are apparently not random mutation events, but specific to a group of genes, suggesting the underlying epigenetic mechanism. The DNA methylation mutant provide useful system for identifying epigenetically-regulated genes important for plant development. 相似文献
765.
Tetraneura nigriabdominalis (Sasaki, 1899) is a galling aphid that is distributed widely in Eurasia. In the present study, a diagnostic multiplex polymerase chain reaction (PCR) protocol was developed to discriminate two types of the cytochrome oxidase subunit I (COI) sequences in this species, and its usefulness was examined from 25 samples of T. nigriabdominalis. Multiplex PCR and electrophoresis revealed that 10 and 15 samples had one band of 133 bp (type A) and 426 bp (type B), respectively. This discrimination was identical to the division of the 25 samples based on the alignments of COI sequences (511 bp), indicating high accuracy of this protocol in distinguishing the two types. This protocol is useful for studying microgeographic distributions of the two types and genetic diversities in T. nigriabdominalis. 相似文献
766.
Hiroki Takakuwa Tetsu Yamashiro Mai Q. Le Lien S. Phuong Hiroichi Ozaki Ryota Tsunekuni Tatsufumi Usui Hiroshi Ito Tsuyoshi Yamaguchi Toshihiro Ito Toshiyuki Murase Etsuro Ono Koichi Otsuki 《Microbiology and immunology》2010,54(1):58-62
To estimate the prevalence of influenza A subtype H5N1 viruses among domestic ducks in the period between October and November 2006 when H5N1 outbreaks had been absent, 1106 healthy ducks raised in northern Vietnam were collected. Inoculation of all throat and cloacae samples into embryonated eggs resulted in the isolation of subtype H3N8 in 13 ducks, but not H5N1 viruses. Serological analyses demonstrated that five ducks (0.45%) solely developed H5N1 subtype-specific hemagglutinin-inhibiting and neuraminidase-inhibiting antibodies together with anti-non-structural protein 1 antibodies. The results suggested that the ducks were naturally infected with H5N1 viruses when obvious H5N1 outbreaks were absent. 相似文献
767.
Tetsuji Sato Michinari Kaneko Wichai Ekataksin Kenjiro Wake 《Cell and tissue research》1995,279(1):25-36
Immunohistochemistry for neuron-specific enolase (NSE) revealed that NSE is localized in both a limited number of pinealocytes and intrinsic afferent neurons in the pineal organ of the domestic fowl. Furthermore, a computer-assisted three-dimensional imaging technique allowed to clarify the reverse distributional pattern of both elements: NSE-positive pinealocytes displayed a dense distribution especially in the vesicular portion of the gland, whereas NSE-immunoreactive nerve cells were mainly found in the pineal stalk. The number of NSE-positive intrinsic neurons in the pineal organ of chickens decreased rapidly after hatching, with a concentration of these elements in the basal portion (stalk) of the pineal organ. On the other hand, immunoreactive pinealocytes increased remarkably in the end-vesicle of the organ with age, followed by a gradual expansion toward the proximal portion. Thus, the spectacular increase in NSE-positive pinealocytes and the progressive reduction of reactive neurons occurred in parallel during the course of post-hatching development. NSE-immunoreactive pinealocytes displayed morphological characteristics of bipolar elements, endowed with an apical protrusion into the pineal lumen and a short basal process at younger stages, whereas multipolar types of NSE-positive pinealocytes were predominantly found in the adult domestic fowl. These results indicate that in the pineal organ of the domestic fowl (1) the ontogenetic expansion of NSE-immunoreactive pinealocytes is paralleled by a regressive afferent innervation, (2) the NSE-positive pinealocytes transform from a bipolar (columnar) type to a multipolar type during post-hatching development, and (3) these ontogenetic changes in the NSE-immunoreactivity and morphology of pinealocytes may reflect the development of a neurosecretory-like capacity of the organ. 相似文献