全文获取类型
收费全文 | 27633篇 |
免费 | 4837篇 |
国内免费 | 3933篇 |
专业分类
化学 | 20643篇 |
晶体学 | 317篇 |
力学 | 1539篇 |
综合类 | 226篇 |
数学 | 3855篇 |
物理学 | 9823篇 |
出版年
2024年 | 19篇 |
2023年 | 479篇 |
2022年 | 560篇 |
2021年 | 779篇 |
2020年 | 1074篇 |
2019年 | 1098篇 |
2018年 | 940篇 |
2017年 | 926篇 |
2016年 | 1355篇 |
2015年 | 1374篇 |
2014年 | 1606篇 |
2013年 | 2137篇 |
2012年 | 2516篇 |
2011年 | 2610篇 |
2010年 | 1871篇 |
2009年 | 1761篇 |
2008年 | 1995篇 |
2007年 | 1742篇 |
2006年 | 1551篇 |
2005年 | 1431篇 |
2004年 | 1187篇 |
2003年 | 947篇 |
2002年 | 1029篇 |
2001年 | 861篇 |
2000年 | 656篇 |
1999年 | 576篇 |
1998年 | 470篇 |
1997年 | 419篇 |
1996年 | 400篇 |
1995年 | 361篇 |
1994年 | 312篇 |
1993年 | 215篇 |
1992年 | 214篇 |
1991年 | 202篇 |
1990年 | 167篇 |
1989年 | 120篇 |
1988年 | 87篇 |
1987年 | 71篇 |
1986年 | 87篇 |
1985年 | 61篇 |
1984年 | 37篇 |
1983年 | 33篇 |
1982年 | 19篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1957年 | 4篇 |
1936年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Jia Tian-Cong Guo Jin-Tao Wang Zhen Zhu Xiao-Shan Zhang Qian-Xin Chen Ping Yao Kun Lv Wen-Ying Liu Guo-Guang 《Journal of Radioanalytical and Nuclear Chemistry》2019,321(3):823-829
Journal of Radioanalytical and Nuclear Chemistry - In the present work the final products of coumarin radiation chemical transformation are investigated by chromatography. During radiolysis of... 相似文献
33.
34.
针对学生实验课积极性不高、实验教学效果不理想的问题,对一门选修课"精细化工"的实验进行了重新思考和设计,让学生参与从实验具体内容制定、操作到结果讨论的整个过程,并首次以"递进式"实验的方式由学生参与第2次实验(基于前一个实验的改进和完善),使学生了解理论知识转化为可行实验方案的具体做法,切身体会在实验原理相同的情况下,实验方案的细微调整对实验结果的巨大影响。结果表明,这种"以学生为中心"的改进能让学生注重实验细节,同时关注实验失败的原因,并在第2次实验中及时修正。这为学生实验综合素质的培养提供了一种教学思路。 相似文献
35.
Dr. Mara Beltrán-Gastélum Dr. Berta Esteban-Fernández de Ávila Dr. Hua Gong Dr. Pooyath Lekshmy Venugopalan Prof. Dr. Tibor Hianik Prof. Dr. Joseph Wang Veronika Subjakova 《Chemphyschem》2019,20(23):3177-3180
Herein, we report ultrasound-propelled graphene-oxide coated gold nanowire motors, functionalized with fluorescein-labeled DNA aptamers (FAM-AIB1-apt), for qualitative detection of overexpressed AIB1 oncoproteins in MCF-7 breast cancer cells. The movement of nanomotors under the ultrasound field facilitated intracellular uptake and resulted in a faster aptamer binding with the target protein and thus faster fluorescence recovery. The propulsion behavior of the aptamer functionalized nanomotors greatly enhanced the fluorescence intensity compared to static conditions. The new aptamer@nanomotor-based strategy offers considerable potential for further development of sensing methodologies towards diagnosis of breast cancer. 相似文献
36.
37.
Wu Fang Guo Xiaoxue Hao Gazi Hu Yubing Jiang Wei 《Journal of Solid State Electrochemistry》2019,23(9):2627-2637
Journal of Solid State Electrochemistry - Developing low-cost and earth-abundant electrocatalysts with high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER)... 相似文献
38.
Han Jing Sun Youhong Guo Wei Deng Sunhua Hou Chuanbin Qu Lili Li Qiang 《Journal of Thermal Analysis and Calorimetry》2019,135(4):2287-2296
Journal of Thermal Analysis and Calorimetry - In this study, the non-isothermal pyrolysis method was used to investigate the pyrolysis characteristics of oil shale from four areas: namely Nongan,... 相似文献
39.
Zhou Shuiping Zhou Xiaoyang Tang Gen Guo Xiang Pang Aimin 《Journal of Thermal Analysis and Calorimetry》2020,140(5):2529-2540
Journal of Thermal Analysis and Calorimetry - Differences of thermal decomposition characteristics and combustion properties between CL-20-based propellants and HMX-based propellants were... 相似文献
40.
Mohit Jaiswal Trang T. Tran Qingjiang Li Xin Yan Mingwei Zhou Krishnendu Kundu Gail E. Fanucci Zhongwu Guo 《Chemical science》2020,11(46):12522
Metabolic glycan engineering (MGE) coupled with nitroxide spin-labeling (SL) was utilized to investigate the heterogeneous environment of cell surface glycans in select cancer and normal cells. This approach exploited the incorporation of azides into cell surface glycans followed by a click reaction with a new nitroxide spin label. Both sialic acid and N-acetylglucosamine (GlcNAc) were targeted for spin labelling. Although each of these moieties experiences a diverse and heterogeneous glycan environment, their EPR spectra and hence mobility are both characterized as a linear combination of two distinct spectra where one component reflects a highly mobile or uncrowded micro-environment with the second component reflecting more restricted motion, reflective of increased crowding and packing within the glycocalyx. What differs among the spectra of the targeted glycans is the relative percentage of each component, with sialic acid moieties experiencing on average an ∼80% less crowded environment, where conversely GlcNAc/GalNAz labeled sites reported on average a ∼50% more crowded environment. These distinct environments are consistent with the organization of sugar moieties within cellular glycans where some residues occur close to the cell membrane/protein backbone (i.e. more restricted) and others are more terminal in the glycan (i.e. more mobile). Strikingly, different cell lines displayed varied relative populations of these two components, suggesting distinctive glycan packing, organization, and composition of different cells. This work demonstrates the capability of SDSL EPR to be a broadly useful tool for studying glycans on cells, and interpretation of the results provides insights for distinguishing the differences and changes in the local organization and heterogeneity of the cellular glycocalyx.Metabolic glycan engineering (MGE) coupled with nitroxide spin-labeling (SL) was utilized to investigate the heterogeneous environment of cell surface glycans in select cancer and normal cells. 相似文献