全文获取类型
收费全文 | 19579篇 |
免费 | 3499篇 |
国内免费 | 3248篇 |
专业分类
化学 | 16095篇 |
晶体学 | 249篇 |
力学 | 1048篇 |
综合类 | 291篇 |
数学 | 2283篇 |
物理学 | 6360篇 |
出版年
2024年 | 24篇 |
2023年 | 429篇 |
2022年 | 469篇 |
2021年 | 654篇 |
2020年 | 935篇 |
2019年 | 986篇 |
2018年 | 719篇 |
2017年 | 671篇 |
2016年 | 1068篇 |
2015年 | 1064篇 |
2014年 | 1200篇 |
2013年 | 1491篇 |
2012年 | 1780篇 |
2011年 | 1809篇 |
2010年 | 1258篇 |
2009年 | 1227篇 |
2008年 | 1347篇 |
2007年 | 1167篇 |
2006年 | 1036篇 |
2005年 | 955篇 |
2004年 | 793篇 |
2003年 | 796篇 |
2002年 | 944篇 |
2001年 | 837篇 |
2000年 | 532篇 |
1999年 | 456篇 |
1998年 | 258篇 |
1997年 | 209篇 |
1996年 | 186篇 |
1995年 | 183篇 |
1994年 | 137篇 |
1993年 | 116篇 |
1992年 | 107篇 |
1991年 | 105篇 |
1990年 | 97篇 |
1989年 | 56篇 |
1988年 | 44篇 |
1987年 | 37篇 |
1986年 | 45篇 |
1985年 | 27篇 |
1984年 | 23篇 |
1983年 | 15篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1979年 | 4篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1959年 | 5篇 |
1957年 | 5篇 |
1936年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Hua Saixiang Zhu Huichao Wang Xiao Wu Mingyuan Wu Qingyun Liu Jiuyi Yang Jianjun Zhang Jianan 《Cellulose (London, England)》2022,29(13):7465-7475
Cellulose - Ultraviolet (UV) protective cotton fabric is a convenient and reliable way to protect human body from sunlight. Herein, a polymerizable UV-absorber,... 相似文献
3.
Applied Mathematics and Mechanics - Spiral springs have a wide range of applications in various fields. As a result of the complexity of friction, few theoretical analyses of spring belts under... 相似文献
4.
对晶体硅(c-Si)太阳能电池而言, 氧化铝(AlOx)是一种广泛使用的钝化材料, 因为它具有优异的沉积保形性和良好的钝化质量. 为了确保AlOx发挥其良好的钝化效果, 在沉积后退火并氢化处理是必不可少的. 通过在AlOx薄膜上沉积氢化氮化硅(SiNx:H)来实现氢化, 利用开尔文探针力显微镜研究了在不同热处理和氢化作用下, AlOx/SiNx:H双层薄膜功函数的变化, 并基于沉积薄膜所含氢与固定电荷展开了讨论. 发现钝化质量和功函数之间有相关性, 影响因素包括薄膜厚度、氢化与热处理顺序. 相似文献
5.
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
6.
Zhen Xi 《中国科学:化学(英文版)》2015,(3):434-435
Redox-based post-translational modification of protein thiols has become an attractive strategy in cellular homeostasis and cell signaling.Due to the reductive end of the redox buffer network,the vicinal dithiol-containing proteins(VDPs)maintains an appropriate oxidation-reduction state of proteins through the reversible transformation from vicinal dithiols to disulfide,which is responsible for a variety of 相似文献
7.
8.
We present the fabrication of core-shell-satellite Au@SiO2-Pt nanostructures and demonstrate that LSPR excitation of the core Au nanoparticle can induce plasmon coupling effect to initiate photocatalytic hydrogen generation from decomposition of formic acid. Further studies suggest that the plasmon coupling effect induces a strong local electric field between the Au core and Pt nanoparticles on the SiO2 shell, which enables creation of hot electrons on the non-plasmonic-active Pt nanoparticles to participate hydrogen evolution reaction on the Pt surface. In addition, small SiO2 shell thickness is required in order to obtain a strong plamon coupling effect and achieve efficient photocatalytic activities for hydrogen generation. 相似文献
9.
Hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have been deemed as clean and sustainable strategies to solve the energy crisis and environmental problems. Various catalysts have been developed to promote the process of HER and OER. Among them, two-dimensional covalent organic frameworks (2D COFs) have received great attention due to their diverse and designable structure. In this minireview, we mainly summarize the diverse linkages of 2D COFs and strategies for enhancing the catalytic performance of 2D COFs for HER and OER, such as introducing active building blocks, metal ions and tailored linkages. Furthermore, a brief outlook for the development directions of COFs in the field of HER and OER is provided, expecting to stimulate new opportunities in future research. 相似文献
10.
The Effect of the Spacer of Bis(biurea) Ligands on the Structure of A2L3‐type (A=anion) Phosphate Complexes 下载免费PDF全文
Prof. Biao Wu Dr. Shaoguang Li Prof. Yibo Lei Prof. Huaiming Hu Dr. Nader de Sousa Amadeu Prof. Dr. Christoph Janiak Dr. Jennifer S. Mathieson Dr. De‐Liang Long Prof. Leroy Cronin Prof. Xiao‐Juan Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2588-2593
By tuning the length and rigidity of the spacer of bis(biurea) ligands L, three structural motifs of the A2L3 complexes (A represents anion, here orthophosphate PO43?), namely helicate, mesocate, and mono‐bridged motif, have been assembled by coordination of the ligand to phosphate anion. Crystal structure analysis indicated that in the three complexes, each of the phosphate ions is coordinated by twelve hydrogen bonds from six surrounding urea groups. The anion coordination properties in solution have also been studied. The results further demonstrate the coordination behavior of phosphate ion, which shows strong tendency for coordination saturation and geometrical preference, thus allowing for the assembly of novel anion coordination‐based structures as in transition‐metal complexes. 相似文献