全文获取类型
收费全文 | 83468篇 |
免费 | 480篇 |
国内免费 | 404篇 |
专业分类
化学 | 28034篇 |
晶体学 | 872篇 |
力学 | 6787篇 |
数学 | 32210篇 |
物理学 | 16449篇 |
出版年
2020年 | 60篇 |
2019年 | 77篇 |
2018年 | 10472篇 |
2017年 | 10289篇 |
2016年 | 6137篇 |
2015年 | 924篇 |
2014年 | 414篇 |
2013年 | 574篇 |
2012年 | 4025篇 |
2011年 | 10759篇 |
2010年 | 5766篇 |
2009年 | 6193篇 |
2008年 | 6861篇 |
2007年 | 8985篇 |
2006年 | 494篇 |
2005年 | 1566篇 |
2004年 | 1789篇 |
2003年 | 2171篇 |
2002年 | 1220篇 |
2001年 | 403篇 |
2000年 | 457篇 |
1999年 | 237篇 |
1998年 | 262篇 |
1997年 | 218篇 |
1996年 | 269篇 |
1995年 | 159篇 |
1994年 | 145篇 |
1993年 | 187篇 |
1992年 | 149篇 |
1991年 | 142篇 |
1990年 | 120篇 |
1989年 | 124篇 |
1988年 | 136篇 |
1987年 | 132篇 |
1986年 | 135篇 |
1985年 | 158篇 |
1984年 | 147篇 |
1983年 | 82篇 |
1982年 | 117篇 |
1981年 | 116篇 |
1980年 | 119篇 |
1979年 | 109篇 |
1978年 | 89篇 |
1977年 | 85篇 |
1976年 | 69篇 |
1975年 | 62篇 |
1974年 | 63篇 |
1973年 | 56篇 |
1914年 | 45篇 |
1909年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Yuki Shintani Taku Ohtomi Dr. Aya Shibata Dr. Yoshiaki Kitamura Koichiro M. Hirosawa Prof. Kenichi G. N. Suzuki Prof. Masato Ikeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202104421
Aqueous self-assembly of short peptides has attracted growing attention for the construction of supramolecular materials for various bioapplications. Herein, we describe how the thermolysin-assisted biocatalytic construction of a dipeptide hydrazide from an N-protected amino acid and an amino acid hydrazide leads to the formation of thermally stable supramolecular hydrogels. In addition, we demonstrate the post-assembly modification of the supramolecular architectures constructed in situ tethering hydrazide groups as a chemical handle by means of fluorescence imaging. 相似文献
2.
Takumi Watanabe Yuichiro Nishizawa Haruka Minato Dr. Chihong Song Prof. Dr. Kazuyoshi Murata Prof. Dr. Daisuke Suzuki 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(23):8934-8938
The three-dimensional structure of nanocomposite microgels was precisely determined by cryo-electron micrography. Several nanocomposite microgels that differ with respect to their nanocomposite structure, which were obtained from seeded emulsion polymerization in the presence of microgels, were used as model nanocomposite materials for cryo-electron micrography. The obtained three-dimensional segmentation images of these nanocomposite microgels provide important insights into the interactions between the hydrophobic monomers and the microgels, that is, hydrophobic styrene monomers recognize molecular-scale differences in polarity within the microgels during the emulsion polymerization. This result led to the formation of unprecedented multi-layered nanocomposite microgels, which promise substantial potential in colloidal applications. 相似文献
3.
In the paper, the authors establish several integral representations for the generating functions of the large and little Schröder numbers and for the large and little Schröder numbers. 相似文献
4.
Mesoscopic modeling at the pore scale offers great promise in exploring the underlying structure transport performance of flow through porous media. The present work studies the fluid flow subjected to capillarity-induced resonance in porous media characterized by different porous structure and wettability. The effects of porosity and wettability on the displacement behavior of the fluid flow through porous media are discussed. The results are presented in the form of temporal evolution of percentage saturation and displacement of the fluid front through porous media. The present study reveals that the vibration in the form of acoustic excitation could be significant in the mobilization of fluid through the porous media. The dependence of displacement of the fluid on physicochemical parameters like wettability of the surface, frequency along with the porosity is analyzed. It was observed that the mean displacement of the fluid is more in the case of invading fluid with wetting phase where the driving force strength is not so dominant. 相似文献
5.
6.
Sarah Peluse 《Israel Journal of Mathematics》2018,227(1):379-396
We prove that the group of diffeomorphisms of the interval [0, 1] contains surface groups whose action on (0, 1) has no global fix point and such that only countably many points of the interval (0, 1) have non-trivial stabiliser. 相似文献
7.
8.
9.
10.
S. V. Panin I. V. Vlasov V. P. Sergeev B. B. Ovechkin P. O. Marushchak Sunder Ramasubbu P. S. Lyubutin V. V. Titkov 《Physical Mesomechanics》2015,18(3):261-272
The structure and properties of 12Cr1MoV steel irradiated with a zirconium ion beam were studied by optical microscopy, scanning electron microscopy, and micro- and nanoindentation. It is shown that the modification covers the entire cross-section of the irradiated specimens to a depth of 1 mm. The data on irradiation-induced structural changes are used to interpret the changes in mechanical properties of the irradiated specimens under static and cyclic loading. Particular attention is given to analysis of strain estimation by the digital image correlation method. 相似文献