全文获取类型
收费全文 | 69936篇 |
免费 | 15903篇 |
国内免费 | 6533篇 |
专业分类
化学 | 65024篇 |
晶体学 | 795篇 |
力学 | 2737篇 |
综合类 | 431篇 |
数学 | 6170篇 |
物理学 | 17215篇 |
出版年
2024年 | 37篇 |
2023年 | 714篇 |
2022年 | 854篇 |
2021年 | 1345篇 |
2020年 | 2668篇 |
2019年 | 3838篇 |
2018年 | 2263篇 |
2017年 | 1861篇 |
2016年 | 4904篇 |
2015年 | 5110篇 |
2014年 | 5444篇 |
2013年 | 6590篇 |
2012年 | 6133篇 |
2011年 | 5550篇 |
2010年 | 5190篇 |
2009年 | 5189篇 |
2008年 | 4874篇 |
2007年 | 4043篇 |
2006年 | 3589篇 |
2005年 | 3409篇 |
2004年 | 2880篇 |
2003年 | 2448篇 |
2002年 | 3193篇 |
2001年 | 2317篇 |
2000年 | 2038篇 |
1999年 | 1151篇 |
1998年 | 690篇 |
1997年 | 641篇 |
1996年 | 550篇 |
1995年 | 461篇 |
1994年 | 434篇 |
1993年 | 311篇 |
1992年 | 259篇 |
1991年 | 278篇 |
1990年 | 205篇 |
1989年 | 175篇 |
1988年 | 146篇 |
1987年 | 121篇 |
1986年 | 93篇 |
1985年 | 78篇 |
1984年 | 53篇 |
1983年 | 51篇 |
1982年 | 44篇 |
1981年 | 39篇 |
1980年 | 26篇 |
1979年 | 8篇 |
1976年 | 10篇 |
1975年 | 14篇 |
1974年 | 8篇 |
1936年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 671 毫秒
1.
2.
Qianqian Fan Zirui Liu Feng Qiu Prof. Yong Mao Prof. Qingju Liu Prof. Longzhou Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(63):e202202700
The artificially accurate design of nonmetal electrocatalysts’ active site has been a huge challenge because no pure active species with the specific structure could be strictly controlled by traditional synthetic methods. Species with a multiconfiguration in the catalyst hinder identification of the active site and the subsequent comprehension of the reaction mechanism. We have developed a novel electro-assisted molecular assembly strategy to obtain a pure pentagon ring on perfect graphene avoiding other reconstructed structures. More importantly, the active atom was confirmed by the subtle passivation process as the topmost carbon atom. Recognition of the carbon-defect electrocatalysis reaction mechanism was first downsized to the single-atom scale from the experimental perspective. It is expected that this innovative electro-assisted molecular assembly strategy could be extensively applied in the active structure-controlled synthesis of nonmetal electrocatalysts and verification of the exact active atom. 相似文献
3.
Yujie Gao Zhiye Qiu Lei Liu Mengmeng Li Bingjie Xu Dan Yu Dongming Qi Jindan Wu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2191-2212
Refractory wounds have always been an important issue to healthcare systems, whose healing process is always delayed by multiple factors, including bacterial infections, chronic inflammation, and excessive exudates, etc. Employing multifunctional wound dressings is recognized as an effective strategy to deal with refractory wounds, which has yielded promising outcomes in recent years. Among these advanced wound dressings, fibrous dressings have gained growing attention due to their unique merits. Such wound dressings have demonstrated great potential in delivering theranostic agents, such as antibacterial agents, anti-inflammatory drugs, growth factors, and diagnostic probes, etc., for the purposes of accelerating wound healing. This paper reviews the development of multifunctional fibrous dressings and their applications in treating refractory wounds. The construction approaches of novel fibrous dressing with capabilities of antibacterial, anti-inflammation, exudate management and diagnosis were also introduced. Furthermore, the existing problems and challenges are also discussed briefly. 相似文献
4.
Tian Jie Yang Weifeng Chen Min Zheng Minfang Chen Ding Qiu Yusheng 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):1039-1049
Journal of Radioanalytical and Nuclear Chemistry - This study presents a time-efficient method of analysing 210Pb, 210Bi, and 210Po in natural waters. The optimum pH (1.00), temperature... 相似文献
5.
针对公众参与的语言信息多属性群决策问题,研究了考虑参与者满意度的概率语言多属性群决策方法。首先,根据参与者的语言评价信息确定并规范化概率语言决策矩阵。然后,对大群体进行共识分析,由最大化参与者群体的满意度构建线性规划模型,确定参与者群组的权重;构造正、负理想方案的评价向量,构建多目标规划模型,用拉格朗日乘子法求解属性权重;定义各方案的加权贴近度,并以此对方案进行排序和优选。最后,通过新型智慧城市市民获得感评价案例验证了模型的可行性和有效性。 相似文献
6.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
7.
Acta Mechanica Sinica - 相似文献
8.
Sun Guo-Hua Dong Qian Bezerra V. B. Dong Shi-Hai 《Journal of mathematical chemistry》2022,60(4):605-612
Journal of Mathematical Chemistry - The analytical solutions of an asymmetric double well potential $$V(x)=a\, x^2-b\, x^3+c\, x^4$$ are found to be a triconfluent Heun function $$H_{T}(\alpha ,... 相似文献
9.
Bingjie Chen Dr. Lianhai Zu Dr. Yao Liu Dr. Ruijing Meng Yutong Feng Prof. Chengxin Peng Feng Zhu Tianzi Hao Jiajia Ru Prof. Yonggang Wang Prof. Jinhu Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(8):3161-3166
Incorporating nanoscale Si into a carbon matrix with high dispersity is desirable for the preparation of lithium-ion batteries (LIBs) but remains challenging. A space-confined catalytic strategy is proposed for direct superassembly of Si nanodots within a carbon (Si NDs⊂C) framework by copyrolysis of triphenyltin hydride (TPT) and diphenylsilane (DPS), where Sn atomic clusters created from TPT pyrolysis serve as the catalyst for DPS pyrolysis and Si catalytic growth. The use of Sn atomic cluster catalysts alters the reaction pathway to avoid SiC generation and enable formation of Si NDs with reduced dimensions. A typical Si NDs⊂C framework demonstrates a remarkable comprehensive performance comparable to other Si-based high-performance half LIBs, and higher energy densities compared to commercial full LIBs, as a consequence of the high dispersity of Si NDs with low lithiation stress. Supported by mechanic simulations, this study paves the way for construction of Si/C composites suitable for applications in future energy technologies. 相似文献
10.
Ruirui Xu Kun Wang Haoying Liu Prof. Dr. Weijun Tang Dr. Huaming Sun Prof. Dr. Dong Xue Prof. Dr. Jianliang Xiao Prof. Dr. Chao Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22143-22148
A ruthenium-catalyzed formal anti-Markovnikov hydroamination of allylic alcohols for the synthesis of chiral γ-amino alcohols is presented. Proceeding via an asymmetric hydrogen-borrowing process, the catalysis allows racemic secondary allylic alcohols to react with various amines, affording enantiomerically enriched chiral γ-amino alcohols with broad substrate scope and excellent enantioselectivities (68 examples, up to >99 % ee). 相似文献