全文获取类型
收费全文 | 37048篇 |
免费 | 5771篇 |
国内免费 | 4394篇 |
专业分类
化学 | 19963篇 |
晶体学 | 387篇 |
力学 | 1553篇 |
综合类 | 256篇 |
数学 | 3173篇 |
物理学 | 9846篇 |
无线电 | 12035篇 |
出版年
2024年 | 115篇 |
2023年 | 801篇 |
2022年 | 1025篇 |
2021年 | 1313篇 |
2020年 | 1322篇 |
2019年 | 1336篇 |
2018年 | 1120篇 |
2017年 | 1165篇 |
2016年 | 1472篇 |
2015年 | 1726篇 |
2014年 | 2085篇 |
2013年 | 2704篇 |
2012年 | 3140篇 |
2011年 | 3407篇 |
2010年 | 2462篇 |
2009年 | 2551篇 |
2008年 | 2715篇 |
2007年 | 2510篇 |
2006年 | 2171篇 |
2005年 | 1775篇 |
2004年 | 1362篇 |
2003年 | 1093篇 |
2002年 | 1102篇 |
2001年 | 935篇 |
2000年 | 833篇 |
1999年 | 713篇 |
1998年 | 574篇 |
1997年 | 505篇 |
1996年 | 536篇 |
1995年 | 437篇 |
1994年 | 385篇 |
1993年 | 314篇 |
1992年 | 281篇 |
1991年 | 238篇 |
1990年 | 201篇 |
1989年 | 159篇 |
1988年 | 102篇 |
1987年 | 93篇 |
1986年 | 89篇 |
1985年 | 73篇 |
1984年 | 55篇 |
1983年 | 47篇 |
1982年 | 27篇 |
1981年 | 24篇 |
1980年 | 12篇 |
1979年 | 18篇 |
1978年 | 8篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 531 毫秒
1.
High Energy Chemistry - Modification of Polyvinylidene fluoride (PVDF) by radiation grafting is a research hotspot in recent years. In this study, the monomer 2-Hydroxyethyl methacrylate (HEMA) was... 相似文献
2.
3.
Zhang Ya-Li Han Rong-Sheng Chen Liang 《International Journal of Theoretical Physics》2021,60(4):1384-1398
International Journal of Theoretical Physics - In this work, we give an analytical derivation of the reduced density matrix between two qubits in a cavity field, which is described by the quantum... 相似文献
4.
三维异质异构集成技术是实现电子信息系统向着微型化、高效能、高整合、低功耗及低成本方向发展的最重要方法,也是决定信息化平台中微电子和微纳系统领域未来发展的一项核心高技术。文章详细介绍了毫米波频段三维异质异构集成技术的优势、近年来的发展趋势以及面临的挑战。利用硅基MEMS 光敏复合薄膜多层布线工艺可实现异质芯片的低损耗互连,同时三维集成高性能封装滤波器、高辐射效率封装天线等无源元件,还能很好地处理布线间的电磁兼容和芯片间的屏蔽问题。最后介绍了一款新型毫米波三维异质异构集成雷达及其在远距离生命体征探测方面的应用。 相似文献
5.
Ping Xiao Jue Wang Lei Fang Zitong Zhao Xiangshi Sun Xiaochen Liu Haiqiang Cao Pengcheng Zhang Dangge Wang Yaping Li 《Advanced functional materials》2021,31(36):2104068
Neoantigen vaccines and adoptive dendritic cell (DC) transfer are major clinical approaches to initiate personalized immunity in cancer patients. However, the immunization efficacy is largely limited by the in vivo trajectory including neoantigens’ access to resident DCs and DCs’ access to lymph nodes (LNs). Herein, an innovative strategy is proposed to improve personalized immunization through neoantigen-loaded nanovaccines synergized with adoptive DC transfer. It is found that it enables selective delivery of neoantigens to resident DCs and macrophages by coating cancer cell membranes onto neoantigen-loaded nanoparticles. In addition, the nanovaccines promote the secretion of chemokine C-C motif ligand 2 (CCL2), CCL3, and C-X-C motif ligand 10 from macrophages, thus potentiating the access of transferred DCs to LNs. This immunization strategy enables coordinated delivery of identified neoantigens and autologous tumor lysate-derived undefined antigens, leading to initiation of antitumor T cell immunity in a personalized manner. It significantly inhibits tumor growth in prophylactic and established mouse tumor models. The findings provide a new vision for potentiating adoptive cell transfer by nanovaccines, which may open the door to a transformative possibility for improving personalized immunization. 相似文献
6.
Yan He Kangren Kong Zhengxi Guo Weifeng Fang Zaiqiang Ma Haihua Pan Ruikang Tang Zhaoming Liu 《Advanced functional materials》2021,31(26):2101291
Sensitivity and multi-directional motivation are major two factors for developing optimized humidity-response materials, which are promising for sensing, energy production, etc. Organic functional groups are commonly used as the water sensitive units through hydrogen bond interactions with water molecules in actuators. The multi-coordination ability of inorganic ions implies that the inorganic ionic compounds are potentially superior water sensitive units. However, the particle forms of inorganic ionic compounds produced by classical nucleation limit the number of exposed ions to interact with water. Recent progress on the inorganic ionic oligomers has broken through the limitation of classical nucleation, and realized the molecular-scaled incorporation of inorganic ionic compounds into an organic matrix. Here, the incorporation of hydrophilic calcium carbonate ionic oligomers into hydrophobic poly(vinylidene fluoride) (PVDF) is demonstrated. The ultra-small calcium carbonate oligomers within a PVDF film endow it with an ultra-sensitive, reversible, and bidirectional response. The motivation ability is superior to other bidirectional humidity-actuators at present, which realizes self-motivation on an ice surface, converting the chemical potential energy of the humidity gradient from ice to kinetic energy. 相似文献
7.
8.
Donglei Wei Huili Li Chuanqing Yang Jianmin Fu Hou Chen Liangjiu Bai Wenxiang Wang Huawei Yang Lixia Yang Ying Liang 《Journal of polymer science. Part A, Polymer chemistry》2022,60(10):1588-1594
Acridone as a new kind of visible light photocatalyst has been developed to catalyze metal free atom transfer radical polymerization (ATRP). The photocatalyst possess low excited state potential as can undergo an oxidative quenching pathway to initiate ATRP of vinyl monomers. Kinetic study and light on/off reaction demonstrate the “living”/controlled nature of the polymerization by light. Block copolymers can be achieved by using PMMA as macroinitiator to reinitiate polymerization of other vinyl monomers, which shows highly preserved Br chain-end functionality in the synthesized polymers. Moreover, the polymerization can be conducted under air atmosphere as most photocatalysts need anaerobic condition, which may give inspiration of further application of this kind of photocatalyst. 相似文献
9.
Liang Zhao 《Journal of Differential Equations》2019,266(9):5615-5624
In this paper, let be n-dimensional noncompact metric measure space which satisfies Poincaré inequality with some Ricci curvature condition. We obtain a Liouville theorem for positive weak solutions to weighted p-Lichnerowicz equation where are real constants. 相似文献
10.