全文获取类型
收费全文 | 65966篇 |
免费 | 14924篇 |
国内免费 | 5435篇 |
专业分类
化学 | 61848篇 |
晶体学 | 689篇 |
力学 | 2646篇 |
综合类 | 253篇 |
数学 | 6047篇 |
物理学 | 14842篇 |
出版年
2024年 | 34篇 |
2023年 | 683篇 |
2022年 | 731篇 |
2021年 | 1271篇 |
2020年 | 2424篇 |
2019年 | 3689篇 |
2018年 | 2134篇 |
2017年 | 1667篇 |
2016年 | 4856篇 |
2015年 | 4843篇 |
2014年 | 5109篇 |
2013年 | 6255篇 |
2012年 | 5782篇 |
2011年 | 5071篇 |
2010年 | 4846篇 |
2009年 | 4706篇 |
2008年 | 4370篇 |
2007年 | 3514篇 |
2006年 | 3119篇 |
2005年 | 3023篇 |
2004年 | 2576篇 |
2003年 | 2241篇 |
2002年 | 3118篇 |
2001年 | 2295篇 |
2000年 | 1946篇 |
1999年 | 1163篇 |
1998年 | 654篇 |
1997年 | 591篇 |
1996年 | 553篇 |
1995年 | 475篇 |
1994年 | 415篇 |
1993年 | 368篇 |
1992年 | 263篇 |
1991年 | 273篇 |
1990年 | 204篇 |
1989年 | 152篇 |
1988年 | 138篇 |
1987年 | 100篇 |
1986年 | 106篇 |
1985年 | 81篇 |
1984年 | 77篇 |
1983年 | 55篇 |
1982年 | 45篇 |
1981年 | 44篇 |
1980年 | 35篇 |
1979年 | 18篇 |
1976年 | 19篇 |
1975年 | 17篇 |
1974年 | 17篇 |
1973年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
Tian Xiu-Zhi Yang Rui Ma Jia-Jia Ni Yong-Hao Deng Hai-Bo Dai Lei Tan Jiao-Jun Zhang Mei-Yun Jiang Xue 《高分子科学》2022,40(7):789-798
Chinese Journal of Polymer Science - Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments. Herein, polyurethane was... 相似文献
2.
Let p ∈ [1, ∞), q ∈ [1, ∞), α∈ R, and s be a non-negative integer. Inspired by the space JNp introduced by John and Nirenberg(1961) and the space B introduced by Bourgain et al.(2015), we introduce a special John-Nirenberg-Campanato space JNcon(p,q,s) over Rn or a given cube of R;with finite side length via congruent subcubes, which are of some amalgam features. The limit space of such spaces as p →∞ is just the Campanato space which coincides with the space BMO(the space of functions with bounded mean oscillations)when α = 0. Moreover, a vanishing subspace of this new space is introduced, and its equivalent characterization is established as well, which is a counterpart of the known characterization for the classical space VMO(the space of functions with vanishing mean oscillations) over Rn or a given cube of Rn with finite side length.Furthermore, some VMO-H1-BMO-type results for this new space are also obtained, which are based on the aforementioned vanishing subspaces and the Hardy-type space defined via congruent cubes in this article. The geometrical properties of both the Euclidean space via its dyadic system and congruent cubes play a key role in the proofs of all these results. 相似文献
3.
Zeng Qing-Wei Wen Zhuo-Yu Fu Jun-Feng Zhou Nan-Run 《International Journal of Theoretical Physics》2021,60(9):3306-3333
International Journal of Theoretical Physics - A new quantum watermark algorithm is presented by combining maximum pixel difference partitioning with the least significant bit substitution... 相似文献
4.
5.
Nonlinear Dynamics - This paper proposes an optimal parameter design of control scheme for mechanical systems by adopting the Stackelberg game theory. The goal of the control is to drive the... 相似文献
6.
Interactions of the vector breathers for the coupled Hirota system with $$4\times 4$$ 4 × 4 Lax pair
Nonlinear Dynamics - In this paper, we investigate the interactions of the vector breathers for the coupled Hirota system with $$4\times 4$$ Lax pair. Firstly, we give the first-order breather... 相似文献
7.
Science China Mathematics - Linear factor models are familiar tools used in many fields. Several pioneering literatures established foundational theoretical results of the quasi-maximum likelihood... 相似文献
8.
We experimentally analyze the heat capacity and thermal expansion of reference solids in a wide temperature range from several Kelvin to melting temperature,and establish a universal double-linear relation between the experimental heat capacity Cp and thermal expansion β,which is different from the previous models.The universal behavior between heat capacity and thermal expansion is important to predict the thermodynamic parameters at constant pressure,and is helpful for understanding the nature of thermal properties in solids. 相似文献
9.
10.
The influence of different referencing methods on the accuracy of δ13C value measurement of ethanol fuel by gas chromatography/combustion/isotope ratio mass spectrometry 下载免费PDF全文