全文获取类型
收费全文 | 23690篇 |
免费 | 4171篇 |
国内免费 | 4336篇 |
专业分类
化学 | 18753篇 |
晶体学 | 446篇 |
力学 | 1187篇 |
综合类 | 303篇 |
数学 | 2283篇 |
物理学 | 9225篇 |
出版年
2024年 | 52篇 |
2023年 | 399篇 |
2022年 | 895篇 |
2021年 | 921篇 |
2020年 | 1023篇 |
2019年 | 985篇 |
2018年 | 885篇 |
2017年 | 943篇 |
2016年 | 1218篇 |
2015年 | 1335篇 |
2014年 | 1662篇 |
2013年 | 2037篇 |
2012年 | 2324篇 |
2011年 | 2450篇 |
2010年 | 1877篇 |
2009年 | 1717篇 |
2008年 | 1875篇 |
2007年 | 1722篇 |
2006年 | 1546篇 |
2005年 | 1165篇 |
2004年 | 861篇 |
2003年 | 670篇 |
2002年 | 713篇 |
2001年 | 666篇 |
2000年 | 447篇 |
1999年 | 403篇 |
1998年 | 242篇 |
1997年 | 218篇 |
1996年 | 176篇 |
1995年 | 150篇 |
1994年 | 104篇 |
1993年 | 120篇 |
1992年 | 75篇 |
1991年 | 65篇 |
1990年 | 48篇 |
1989年 | 49篇 |
1988年 | 27篇 |
1987年 | 36篇 |
1986年 | 31篇 |
1985年 | 24篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1974年 | 1篇 |
1971年 | 2篇 |
1959年 | 2篇 |
1957年 | 6篇 |
1936年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
1.
Zhang Bing Yang Jie-qin Liu Ying Hu Bin Yang Yang Zhao Li Lu Qiang 《Cellulose (London, England)》2022,29(12):6565-6578
Cellulose - Heating is essential in various biomass pre-treatments and thermal conversion processes. It is of practical significance to study the characteristics of cellulose-lignin and... 相似文献
2.
A numerical model was developed and validated to investigate the fluid–structure interactions between fully developed pipe flow and core–shell-structured microcapsule in a microchannel. Different flow rates and microcapsule shell thicknesses were considered. A sixth-order rotational symmetric distribution of von Mises stress over the microcapsule shell can be observed on the microcapsule with a thinner shell configuration, especially at higher flow rate conditions. It is also observed that when being carried along in a fully developed pipe flow, the microcapsule with a thinner shell tends to accumulate stress at a higher rate compared to that with a thicker shell. In general, for the same microcapsule configuration, higher flow velocity would induce a higher stress level over the microcapsule shell. The deformation gradient was used to capture the microcapsule's deformation in the present study. The effect of Young's modulus on the microcapsule shell on the microcapsule deformation was investigated as well. Our findings will shed light on the understanding of the stability of core–shell-structured microcapsule when subjected to flow-induced shear stress in a microfluidic system, enabling a more exquisite control over the breakup dynamics of drug-loaded microcapsule for biomedical applications. 相似文献
3.
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
4.
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
5.
Dr. Yong-Sheng Wei Dr. Liming Sun Miao Wang Dr. Jinhua Hong Dr. Lianli Zou Hongwen Liu Dr. Yu Wang Dr. Mei Zhang Dr. Zheng Liu Prof. Yinwei Li Prof. Satoshi Horike Prof. Kazu Suenaga Prof. Qiang Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16147-16156
Understanding the thermal aggregation behavior of metal atoms is important for the synthesis of supported metal clusters. Here, derived from a metal–organic framework encapsulating a trinuclear FeIII2FeII complex (denoted as Fe3) within the channels, a well-defined nitrogen-doped carbon layer is fabricated as an ideal support for stabilizing the generated iron nanoclusters. Atomic replacement of FeII by other metal(II) ions (e.g., ZnII/CoII) via synthesizing isostructural trinuclear-complex precursors (Fe2Zn/Fe2Co), namely the “heteroatom modulator approach”, is inhibiting the aggregation of Fe atoms toward nanoclusters with formation of a stable iron dimer in an optimal metal–nitrogen moiety, clearly identified by direct transmission electron microscopy and X-ray absorption fine structure analysis. The supported iron dimer, serving as cooperative metal–metal site, acts as efficient oxygen evolution catalyst. Our findings offer an atomic insight to guide the future design of ultrasmall metal clusters bearing outstanding catalytic capabilities. 相似文献
6.
Analysis and pharmacokinetic study of polyphyllin H in beagle dog plasma after oral administration of Rhizoma Paridis Extracts by LC‐MS/MS
下载免费PDF全文
![点击此处可从《Biomedical chromatography : BMC》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
Jing Zhihong Ling Baoping Yu Yang Qi Wei Zhang Shufang 《Journal of Sol-Gel Science and Technology》2015,73(1):112-117
Journal of Sol-Gel Science and Technology - A novel gas sensing material, La–Y co-doped TiO2 nanoparticles, was synthesized by sol–gel method and applied to detect organic pollutants... 相似文献
8.
JPC – Journal of Planar Chromatography – Modern TLC - A new high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous estimation of... 相似文献
9.
Wu Shang-Zhuo Yu Qiang Li Yue-Hua Cui Guang-Hua 《Research on Chemical Intermediates》2021,47(2):835-851
Research on Chemical Intermediates - Combination of three aromatic carboxylic acids (5-nitroisophthalic acid (H2nip), 2,6-naphthalenedicarboxylic acid (H2ndc), tetrabromoterephthalic acid (H2tbta))... 相似文献
10.