全文获取类型
收费全文 | 2225篇 |
免费 | 305篇 |
国内免费 | 319篇 |
专业分类
化学 | 441篇 |
晶体学 | 5篇 |
力学 | 109篇 |
综合类 | 50篇 |
数学 | 1670篇 |
物理学 | 574篇 |
出版年
2024年 | 14篇 |
2023年 | 56篇 |
2022年 | 67篇 |
2021年 | 69篇 |
2020年 | 94篇 |
2019年 | 84篇 |
2018年 | 81篇 |
2017年 | 70篇 |
2016年 | 63篇 |
2015年 | 61篇 |
2014年 | 82篇 |
2013年 | 231篇 |
2012年 | 89篇 |
2011年 | 94篇 |
2010年 | 87篇 |
2009年 | 112篇 |
2008年 | 118篇 |
2007年 | 151篇 |
2006年 | 120篇 |
2005年 | 138篇 |
2004年 | 100篇 |
2003年 | 115篇 |
2002年 | 102篇 |
2001年 | 85篇 |
2000年 | 93篇 |
1999年 | 89篇 |
1998年 | 92篇 |
1997年 | 62篇 |
1996年 | 49篇 |
1995年 | 23篇 |
1994年 | 23篇 |
1993年 | 22篇 |
1992年 | 15篇 |
1991年 | 13篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有2849条查询结果,搜索用时 15 毫秒
1.
《中国物理 B》2021,30(10):107304-107304
The field of two-dimensional topological semimetals, which emerged at the intersection of two-dimensional materials and topological materials, has been rapidly developing in recent years. In this article, we briefly review the progress in this field. Our focus is on the basic concepts and notions, in order to convey a coherent overview of the field. Some material examples are discussed to illustrate the concepts. We discuss the outstanding problems in the field that need to be addressed in future research. 相似文献
2.
3.
Tetsuya Sato 《Journal of Pure and Applied Algebra》2018,222(10):2888-2896
We show that the Giry monad is not strong with respect to the canonical symmetric monoidal closed structure on the category Meas of all measurable spaces and measurable functions. 相似文献
4.
《Mathematical Methods in the Applied Sciences》2018,41(14):5423-5458
We investigate lp boundedness, the topological structure of solutions set and the asymptotic periodicity of Volterra functional difference equations. The theoretical results are complemented with a set of applications. 相似文献
5.
In this paper, we establish some new Foxby equivalences between some Gorenstein subcategories in the Auslander class 𝒜C(R) and that in the Bass class ?C(S) in a general setting. Our results provide a unification and generalization of some known results and generate some new Foxby equivalences of categories. 相似文献
6.
《Expositiones Mathematicae》2021,39(4):583-589
Chase’s lemma provides a powerful tool for translating properties of (co)products in abelian categories into chain conditions. This note discusses the context in which the lemma is used, making explicit what is often neglected in the literature because of its technical nature. 相似文献
7.
8.
Flexible control of building blocks of photonic crystals enables achieving desirable band structures. Exploration of photonic band extrema has brought many fantastic features to design artificial optical materials, such as Brillouin‐zone‐corner extrema for valley photonic materials and zone‐center extremum for zero‐index metamaterials. However, two such kinds of extrema are always found independently in different photonic crystals. In this work, a kind of valley photonic crystals possessing both zone‐center and zone‐corner band extrema almost at the same frequency is proposed. Inspired by antennas theory, a three‐antenna array (TAA) source is devoted to individually manipulate each extremum. The correlation coefficient is given to determine the coupling efficiency between the TAA source and extrema eigenmodes. By using a source with a high correlation coefficient, these extrema bulk states are selectively excited consistent with their eigenfields. Furthermore, three control cases are shown that multiple extrema points are simultaneously excited, in order to confirm the validity of the correlation coefficient. Finally, a potential application of a beam‐steering device is proposed through selective excitation of ternary extrema. This work develops binary valley states into ternary mix states, rendering more degrees of freedom for on‐chip optical information transport, particularly for beam steering and mode division multiplexing. 相似文献
9.
10.
The contents of topological classification of matter are enriched by non-Hermiticity, such as exceptional points, bulk-edge correspondence, and skin effects. Physically, gain and loss can be introduced by imaginary on-site potentials of lattice Hamiltonians, and the topological phase transition for a cross-linked chain in the presence of such non-Hermiticity is investigated. The topological phase diagram in terms of a winding number is obtained analytically with phase boundaries coinciding with the surfaces of exceptional points. The topologically original edge states with distribution mainly at the joints between domains of different phases are protected even for long chains. The non-Hermitian topological feature can also be reflected by vortex structures in the vector fields of complex eigenenergies, expected values of Pauli matrices, and trajectories of these quantities. This model may be implemented in coupled photonic crystals, fermions trapped in optical lattice, or non-Hermitian electrical-circuit lattices, and the edge states are immune to various kinds of disorders until topological phase transition occurs. This work gives insight into the influence of non-Hermiticity on topological phase of matter. 相似文献