全文获取类型
收费全文 | 23370篇 |
免费 | 3835篇 |
国内免费 | 2609篇 |
专业分类
化学 | 16420篇 |
晶体学 | 265篇 |
力学 | 1412篇 |
综合类 | 243篇 |
数学 | 2654篇 |
物理学 | 8820篇 |
出版年
2024年 | 12篇 |
2023年 | 492篇 |
2022年 | 496篇 |
2021年 | 677篇 |
2020年 | 981篇 |
2019年 | 893篇 |
2018年 | 744篇 |
2017年 | 716篇 |
2016年 | 1080篇 |
2015年 | 992篇 |
2014年 | 1247篇 |
2013年 | 1633篇 |
2012年 | 2070篇 |
2011年 | 2098篇 |
2010年 | 1435篇 |
2009年 | 1380篇 |
2008年 | 1552篇 |
2007年 | 1414篇 |
2006年 | 1354篇 |
2005年 | 1091篇 |
2004年 | 868篇 |
2003年 | 707篇 |
2002年 | 587篇 |
2001年 | 504篇 |
2000年 | 482篇 |
1999年 | 558篇 |
1998年 | 471篇 |
1997年 | 409篇 |
1996年 | 412篇 |
1995年 | 382篇 |
1994年 | 355篇 |
1993年 | 321篇 |
1992年 | 267篇 |
1991年 | 231篇 |
1990年 | 232篇 |
1989年 | 159篇 |
1988年 | 119篇 |
1987年 | 82篇 |
1986年 | 96篇 |
1985年 | 65篇 |
1984年 | 37篇 |
1983年 | 39篇 |
1982年 | 37篇 |
1981年 | 20篇 |
1980年 | 8篇 |
1979年 | 4篇 |
1976年 | 1篇 |
1957年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Herein we summarized some clean preparation examples to emphasize the concept of dual roles design (or named as “two birds one stone strategy”) in green and sustainable chemistry. In those examples, the reactants and/or solvent play dual roles rendering a cleaner organic preparation process. Consequently, both the chemical waste and manufacturing cost could be reduced. 相似文献
22.
Zhu Hong Zeng Xiangbing Han Tianli Li Xuexue Zhu Shuguang Sun Bai Zhou Ping Liu Jinyun 《Journal of Solid State Electrochemistry》2019,23(7):2173-2180
Journal of Solid State Electrochemistry - Since conventional graphite-based anode possesses a low capacity, seeking for high-capacity anode candidates becomes significant for constructing emerging... 相似文献
23.
Recently, iteratively reweighted methods have attracted much interest in compressed sensing, outperforming their unweighted counterparts in most cases. In these methods, decision variables and weights are optimized alternatingly, or decision variables are optimized under heuristically chosen weights. In this paper,we present a novel weighted l1-norm minimization problem for the sparsest solution of underdetermined linear equations. We propose an iteratively weighted thresholding method for this problem, wherein decision variables and weights are optimized simultaneously. Furthermore, we prove that the iteration process will converge eventually. Using the homotopy technique, we enhance the performance of the iteratively weighted thresholding method. Finally, extensive computational experiments show that our method performs better in terms of both running time and recovery accuracy compared with some state-of-the-art methods. 相似文献
24.
Huang Huaijing Wu Zhaoqi Zhu Chuanxi Fei Shao-Ming 《International Journal of Theoretical Physics》2021,60(7):2368-2379
International Journal of Theoretical Physics - Quantifying the quantumness of ensembles is a vital and practical task in quantum information theory. In this paper, we quantify the quantumness of... 相似文献
25.
Nonlinear Dynamics - The paper studies the stability and control of radial deployment of an electric solar wind sail with the consideration of high-order modes of elastic tethers. The electric... 相似文献
26.
Czechoslovak Mathematical Journal - The irregularity of a graph G = (V, E) is defined as the sum of imbalances ∣du ? dv∣ over all edges uv ∈ E, where du denotes the degree... 相似文献
27.
Zhu Xiaoyang Wang Jing Chai Lulu Tang Guangshi Wan Kangni Pan Junqing 《Journal of Solid State Electrochemistry》2022,26(5):1163-1173
Journal of Solid State Electrochemistry - In this work, nanorods like bimetallic Zn/Mn metal–organic-frameworks (MOFs) are proposed as the precursor for preparing MnxOy/porous carbon... 相似文献
28.
Gürbüzbalaban Mert Ruszczyński Andrzej Zhu Landi 《Journal of Optimization Theory and Applications》2022,194(3):1014-1041
Journal of Optimization Theory and Applications - We consider a distributionally robust formulation of stochastic optimization problems arising in statistical learning, where robustness is with... 相似文献
29.
30.
Li Hongying Liu Xiaoxuan Huang Jiaqi Zhu Wenjuan Ding Aimin Yao Chengli Zhu Jinmiao 《Crystallography Reports》2022,67(7):1231-1238
Crystallography Reports - Sodium dodecyl sulfonate and rape pollen were selected as soft and hard templates to induce ZnO formation under hydrothermal conditions, respectively. In the preparation... 相似文献