全文获取类型
收费全文 | 202565篇 |
免费 | 37553篇 |
国内免费 | 52345篇 |
专业分类
化学 | 145886篇 |
晶体学 | 5554篇 |
力学 | 14173篇 |
综合类 | 5785篇 |
数学 | 32122篇 |
物理学 | 88943篇 |
出版年
2024年 | 539篇 |
2023年 | 2597篇 |
2022年 | 6588篇 |
2021年 | 6869篇 |
2020年 | 7181篇 |
2019年 | 7129篇 |
2018年 | 6495篇 |
2017年 | 8116篇 |
2016年 | 8264篇 |
2015年 | 10034篇 |
2014年 | 12136篇 |
2013年 | 15865篇 |
2012年 | 16852篇 |
2011年 | 18250篇 |
2010年 | 15886篇 |
2009年 | 16050篇 |
2008年 | 17650篇 |
2007年 | 16079篇 |
2006年 | 15511篇 |
2005年 | 13382篇 |
2004年 | 10591篇 |
2003年 | 7868篇 |
2002年 | 8069篇 |
2001年 | 7526篇 |
2000年 | 7589篇 |
1999年 | 4889篇 |
1998年 | 3044篇 |
1997年 | 2569篇 |
1996年 | 2475篇 |
1995年 | 2138篇 |
1994年 | 1990篇 |
1993年 | 1842篇 |
1992年 | 1615篇 |
1991年 | 1275篇 |
1990年 | 1198篇 |
1989年 | 1093篇 |
1988年 | 851篇 |
1987年 | 744篇 |
1986年 | 650篇 |
1985年 | 526篇 |
1984年 | 480篇 |
1983年 | 383篇 |
1982年 | 285篇 |
1981年 | 269篇 |
1980年 | 201篇 |
1979年 | 196篇 |
1978年 | 97篇 |
1977年 | 54篇 |
1965年 | 69篇 |
1959年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Meihua Shen Dr. Xinpeng Zhao Dr. Lu Han Nanxi Jin Prof. Song Liu Prof. Tao Jia Prof. Zhijun Chen Prof. Xiuhua Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(20):e202104137
Solar-driven interfacial vaporization by localizing solar-thermal energy conversion to the air−water interface has attracted tremendous attention. In the process of converting solar energy into heat energy, photothermal materials play an essential role. Herein, a flexible solar-thermal material di-cyan substituted 5,12-dibutylquinacridone (DCN−4CQA)@Paper was developed by coating photothermal quinacridone derivatives on the cellulose paper. The DCN−4CQA@Paper combines desired chemical and physical properties, broadband light-absorbing, and shape-conforming abilities that render efficient photothermic vaporization. Notably, synergetic coupling of solar-steam and solar-electricity technologies by integrating DCN−4CQA@Paper and the thermoelectric devices is realized without trade-offs, highlighting the practical consideration toward more impactful solar heat exploitation. Such solar distillation and low-grade heat-to-electricity generation functions can provide potential opportunities for fresh water and electricity supply in off-grid or remote areas. 相似文献
22.
23.
A graphic sequence π =(d1, d2,..., dn) is said to be forcibly k-edge-connected if every realization of π is k-edge-connected. In this paper, we obtain a new sufficient degree condition for π to be forcibly k-edgeconnected. We also show that this new sufficient degree condition implies a strongest monotone degree condition for π to be forcibly 2-edge-connected and a conjecture about a strongest monotone degree condition for π to be forcibly 3-edge-connected due to... 相似文献
24.
Li Jun Zheng Dayong Wei Ning Sun Yunfeng Liu Li Yuan Yuan Jiang Qinghua 《Chemistry of Natural Compounds》2022,58(4):650-652
Chemistry of Natural Compounds - A new quassinoid, dehydrobruceantinol B (1), was isolated from the seeds of Brucea javanica, together with two known compounds, bruceantinol (2) and bruceine A (3).... 相似文献
25.
Journal of Visualization - The increasing availability of spatiotemporal data provides unprecedented opportunities for understanding the structure of an urban area in terms of people’s... 相似文献
26.
International Journal of Theoretical Physics - The Majorana representation, which provides an intuitive way to represent the quantum state by stars on the Bloch sphere, has drawn considerable... 相似文献
27.
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
28.
International Journal of Theoretical Physics - We consider the stationary state of a spin-orbit coupled (SOC) binary Bose-Einstein condensates with dipole-dipole interaction (DDI). Our results are... 相似文献
29.
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
30.
Nonlinear Dynamics - Epilepsy is the second largest neurological disease which seriously threatens human life and health. The one important reason of inducing epileptic seizures is ischemic stroke... 相似文献