全文获取类型
收费全文 | 2383篇 |
免费 | 136篇 |
国内免费 | 2篇 |
出版年
2021年 | 18篇 |
2019年 | 16篇 |
2018年 | 28篇 |
2017年 | 16篇 |
2016年 | 34篇 |
2015年 | 64篇 |
2014年 | 58篇 |
2013年 | 181篇 |
2012年 | 120篇 |
2011年 | 99篇 |
2010年 | 65篇 |
2009年 | 78篇 |
2008年 | 136篇 |
2007年 | 148篇 |
2006年 | 133篇 |
2005年 | 158篇 |
2004年 | 143篇 |
2003年 | 144篇 |
2002年 | 130篇 |
2001年 | 25篇 |
1999年 | 29篇 |
1998年 | 39篇 |
1997年 | 20篇 |
1996年 | 34篇 |
1995年 | 29篇 |
1994年 | 27篇 |
1993年 | 33篇 |
1992年 | 27篇 |
1991年 | 25篇 |
1990年 | 13篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 15篇 |
1985年 | 22篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 27篇 |
1981年 | 39篇 |
1980年 | 19篇 |
1979年 | 15篇 |
1978年 | 16篇 |
1977年 | 14篇 |
1976年 | 17篇 |
1974年 | 12篇 |
1972年 | 10篇 |
1970年 | 12篇 |
1969年 | 11篇 |
1968年 | 13篇 |
1967年 | 17篇 |
排序方式: 共有2521条查询结果,搜索用时 15 毫秒
101.
102.
The component aldehydes in dialdehyde fragments formed by periodate oxidation of oligosaccharides were converted quantitatively into the corresponding (2,4-dinitrophenyl)hydrazones by the simple procedure of treatment with excess (2,4-dinitrophenyl)hydrazine hydrochloride in 1,2-dimethoxyethane. Then, by chromatographic separation of the hydrazones on a small column of silica gel and subsequent spectrophotometric analysis, it was possible to determine the position of glycosidic substitution in μmolar amounts of various types of glucobioses, oligosaccharides of senega, and some synthetic (1→6)-β-D-gluco-oligosaccharides. 相似文献
103.
Susumu Watanabe 《Mycopathologia》1975,57(2):73-76
The observations of Microsporum canis with cryoscanning and scanning electron microscopy without fixation and dehydration were reported. In the former an almost native state was observed through showing some fuzzy outlines due to frost; in the latter it was shown that marked shrinkage and distortion had occured. There were many granules on the surface of the macroconidia though their function is uncertain. 相似文献
104.
Yue Li Steven M. Shea Christine H. Lorenz Hangyi Jiang Ming-Chung Chou Susumu Mori 《PloS one》2013,8(10)
Due to the high sensitivity of diffusion tensor imaging (DTI) to physiological motion, clinical DTI scans often suffer a significant amount of artifacts. Tensor-fitting-based, post-processing outlier rejection is often used to reduce the influence of motion artifacts. Although it is an effective approach, when there are multiple corrupted data, this method may no longer correctly identify and reject the corrupted data. In this paper, we introduce a new criterion called “corrected Inter-Slice Intensity Discontinuity” (cISID) to detect motion-induced artifacts. We compared the performance of algorithms using cISID and other existing methods with regard to artifact detection. The experimental results show that the integration of cISID into fitting-based methods significantly improves the retrospective detection performance at post-processing analysis. The performance of the cISID criterion, if used alone, was inferior to the fitting-based methods, but cISID could effectively identify severely corrupted images with a rapid calculation time. In the second part of this paper, an outlier rejection scheme was implemented on a scanner for real-time monitoring of image quality and reacquisition of the corrupted data. The real-time monitoring, based on cISID and followed by post-processing, fitting-based outlier rejection, could provide a robust environment for routine DTI studies. 相似文献
105.
Susumu Hizukuri 《Bioscience, biotechnology, and biochemistry》2013,77(1):45-49
A linear amylodextrin (average degree of polymerization 12.6) from sweetpotato was crystallized at different temperatures and from different concentrations of solution, and the crystalline type of the recrystallized amylodextrin was examined by X-ray diffraction. It was shown that the crystal type was dependent on the crystallization conditions. The conditions required for the formation of A-, C- and B-type crystals were limited by the following functional relations: 2.5T+C>84, 72<2.5T+C<84, and 2.5T+C<72, respectively, where T is the temperature (°C) at which the amylodextrin was crystallized and C is the concentration (%) of the amylodextrin solution. This relation showed that high temperatures and high concentrations of amylodextrin were favorable for A-type crystal formation and low temperatures and concentrations for B-type crystals, and that the type of crystals formed was more affected by temperature than concentration of the solution. 相似文献
106.
107.
108.
109.
Hiroshi Oshima Umeko Kawaharada Tokuhiko Kasuga Susumu Mitsuhashi 《Microbiology and immunology》1967,11(2):129-132
The phage typing patterns of phage type 52/52A/80/81 staphylococcal strains were changed to type 80/81 and the non-typable group by lysogenization with phages 27 and 146. When a particular strain of Staphylococcus aureus, MS1590 phage type 52/52A/80/81, was lysogenized with phage 146, type 80/81 and the non-typable group strains were produced. According to the comparison of host range of the prophages, it has been concluded that the two strains with different phage typing patterns have different kinds of prophages. 相似文献
110.
Yoshikazu Hashida Katsuaki Takechi Tomomi Abiru Noriyuki Yabe Hiroaki Nagase Koro Hattori Susumu Takio Yoshikatsu Sato Mitsuyasu Hasebe Hirokazu Tsukaya Hiroyoshi Takano 《The Plant journal : for cell and molecular biology》2020,101(6):1318-1330
In Arabidopsis thaliana the ANGUSTIFOLIA (AN) gene regulates the width of leaves by controlling the diffuse growth of leaf cells in the medio‐lateral direction. In the genome of the moss Physcomitrella patens, we found two normal ANs (PpAN1‐1 and 1‐2). Both PpAN1 genes complemented the A. thaliana an‐1 mutant phenotypes. An analysis of spatiotemporal promoter activity of each PpAN1 gene, using transgenic lines that contained each PpAN1‐promoter– uidA (GUS) gene, showed that both promoters are mainly active in the stems of haploid gametophores and in the middle to basal region of the young sporophyte that develops into the seta and foot. Analyses of the knockout lines for PpAN1‐1 and PpAN1‐2 genes suggested that these genes have partially redundant functions and regulate gametophore height by controlling diffuse cell growth in gametophore stems. In addition, the seta and foot were shorter and thicker in diploid sporophytes, suggesting that cell elongation was reduced in the longitudinal direction, whereas no defects were detected in tip‐growing protonemata. These results indicate that both PpAN1 genes in P. patens function in diffuse growth of the haploid and diploid generations but not in tip growth. To visualize microtubule distribution in gametophore cells of P. patens, transformed lines expressing P. patens α‐tubulin fused to sGFP were generated. Contrary to expectations, the orientation of microtubules in the tips of gametophores in the PpAN1‐1/1‐2 double‐knockout lines was unchanged. The relationships among diffuse cell growth, cortical microtubules and AN proteins are discussed. 相似文献