全文获取类型
收费全文 | 2600篇 |
免费 | 87篇 |
国内免费 | 11篇 |
专业分类
化学 | 1629篇 |
晶体学 | 2篇 |
力学 | 87篇 |
数学 | 509篇 |
物理学 | 471篇 |
出版年
2023年 | 17篇 |
2022年 | 19篇 |
2021年 | 38篇 |
2020年 | 52篇 |
2019年 | 47篇 |
2018年 | 34篇 |
2017年 | 39篇 |
2016年 | 72篇 |
2015年 | 51篇 |
2014年 | 81篇 |
2013年 | 125篇 |
2012年 | 160篇 |
2011年 | 210篇 |
2010年 | 132篇 |
2009年 | 105篇 |
2008年 | 159篇 |
2007年 | 190篇 |
2006年 | 152篇 |
2005年 | 115篇 |
2004年 | 106篇 |
2003年 | 92篇 |
2002年 | 84篇 |
2001年 | 35篇 |
2000年 | 37篇 |
1999年 | 29篇 |
1998年 | 32篇 |
1997年 | 33篇 |
1996年 | 29篇 |
1995年 | 24篇 |
1994年 | 16篇 |
1993年 | 23篇 |
1992年 | 28篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 17篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 8篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 17篇 |
1975年 | 9篇 |
1974年 | 10篇 |
排序方式: 共有2698条查询结果,搜索用时 15 毫秒
81.
Vít Kremláček Erik Kertész Prof. Zoltán Benkő Milan Erben Robert Jirásko Prof. Aleš Růžička Prof. Roman Jambor Prof. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(52):13096-13097
Invited for the cover of this issue are Zoltán Benkő, Libor Dostál and co-workers at the University of Pardubice and the Budapest University of Technology and Economics. The image depicts signs for the two different pathways representing the two differing reaction types which were clearly observed for 2,1-benzazaphosphole. Read the full text of the article at 10.1002/chem.202101686 . 相似文献
82.
83.
Li Caldeira Balkeståhl Erik Thomé on behalf of the PANDA Collaboration 《Hyperfine Interactions》2014,229(1-3):79-83
Strangeness and charm production provide an excellent probe of QCD in the confinement domain. With the PANDA detector at FAIR, this can be studied in e.g., hyperon production in the p?p → ?Y reactions. In PANDA, all ground state strange hyperons and single charmed Λ’s will be accessible. Simulations show that the differential cross sections and spin observables can be well reconstructed for these reaction channels. 相似文献
84.
Dr. Liangliang Song Prof. Dr. Erik V. Van der Eycken 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(1):121-144
Polycycles are abundantly present in numerous advanced chemicals, functional materials, bioactive molecules and natural products. However, the strategies for the synthesis of polycycles are limited to classical reactions and transition metal-catalyzed cross-coupling reactions, requiring pre-functionalized starting materials and lengthy synthetic operations. The emergence of novel approaches shows great promise for the fields of organic/medicinal/materials chemistry. Among them, transition metal-catalyzed C−H activation followed by intermolecular annulation reactions prevail, due to their straightforward manner with high atom- and step-economy, providing rapid, concise and efficient methods for the construction of diverse polycycles. Several strategies have been developed for the synthesis of polycycles, relying on sequential multiple C−H activation/annulation, or combination of C−H activation/annulation and further interaction with a proximal group, or merger of C−H activation with a cycloaddition reaction, or in situ formation of the directing group. These are attractive, efficient, step- and atom-economic methods starting from commercially available materials. This Minireview will provide an introduction to transition metal-catalyzed C−H activation for the synthesis of polycycles, helping researchers to discover indirect connections and reveal hidden opportunities. It will also promote the discovery of novel synthetic strategies relying on C−H activation. 相似文献
85.
86.
87.
88.
Ly Dieu Ha Poul Erik Hansen Fritz Duus Hung Dinh Pham Lien‐Hoa D. Nguyen 《Magnetic resonance in chemistry : MRC》2012,50(3):242-245
Four new prenylated depsidones, oliveridepsidones A–D, were isolated from the bark of Garcinia oliveri collected in Vietnam. Their structures were elucidated using mainly NMR techniques (1H and 13C NMR, HMQC, HMBC and NOE experiments). Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
89.
90.
Dr. Alexander Hoffmann Cooper Citek Dr. Stephan Binder Arne Goos Prof. Dr. Michael Rübhausen Oliver Troeppner Prof. Dr. Ivana Ivanović‐Burmazović Prof. Dr. Erik C. Wasinger Prof. Dr. T. Daniel P. Stack Prof. Dr. Sonja Herres‐Pawlis 《Angewandte Chemie (International ed. in English)》2013,52(20):5398-5401