全文获取类型
收费全文 | 3087篇 |
免费 | 167篇 |
国内免费 | 23篇 |
专业分类
化学 | 2172篇 |
晶体学 | 17篇 |
力学 | 177篇 |
数学 | 495篇 |
物理学 | 416篇 |
出版年
2023年 | 26篇 |
2022年 | 18篇 |
2021年 | 56篇 |
2020年 | 78篇 |
2019年 | 67篇 |
2018年 | 49篇 |
2017年 | 35篇 |
2016年 | 102篇 |
2015年 | 101篇 |
2014年 | 136篇 |
2013年 | 167篇 |
2012年 | 281篇 |
2011年 | 287篇 |
2010年 | 179篇 |
2009年 | 148篇 |
2008年 | 213篇 |
2007年 | 205篇 |
2006年 | 179篇 |
2005年 | 157篇 |
2004年 | 157篇 |
2003年 | 132篇 |
2002年 | 130篇 |
2001年 | 32篇 |
2000年 | 25篇 |
1999年 | 16篇 |
1998年 | 15篇 |
1997年 | 24篇 |
1996年 | 30篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 16篇 |
1992年 | 15篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1968年 | 15篇 |
1967年 | 9篇 |
排序方式: 共有3277条查询结果,搜索用时 93 毫秒
21.
Asma Mani Tao Feng Albert Gandioso Robin Vinck Anna Notaro Lisa Gourdon Pierre Burckel Bruno Saubaméa Olivier Blacque Kevin Cariou Jamel-Eddine Belgaied Hui Chao Gilles Gasser 《Angewandte Chemie (International ed. in English)》2023,62(20):e202218347
Five osmium(II) polypyridyl complexes of the general formula [Os(4,7-diphenyl-1,10-phenanthroline)2 L ]2+ were synthesized as photosensitizers for photodynamic therapy by varying the nature of the ligand L . Thanks to the pronounced π-extended structure of the ligands and the heavy atom effect provided by the osmium center, these complexes exhibit a high absorption in the near-infrared (NIR) region (up to 740 nm), unlike related ruthenium complexes. This led to a promising phototoxicity in vitro against cancer cells cultured as 2D cell layers but also in multicellular tumor spheroids upon irradiation at 740 nm. The complex [Os(4,7-diphenyl-1,10-phenanthroline)2(2,2′-bipyridine)]2+ was found to be the most efficient against various cancer cell lines, with high phototoxicity indexes. Experiments on CT26 tumor-bearing BALB/c mice also indicate that the OsII complexes could significantly reduce tumor growth following 740 nm laser irradiation. The high phototoxicity in the biological window of this structurally simple complex makes it a promising photosensitizer for cancer treatment. 相似文献
22.
Prof. Yoann Olivier Prof. Juan-Carlos Sancho-García 《Angewandte Chemie (International ed. in English)》2023,62(38):e202305501
New heterocyclic diradicaloids based on boron and nitrogen-doped polycyclic systems with open-shell ground-states are obtained via concomitant structural and quinoidal extensions, thus allowing to merge the best of both design strategies. A combination of experimental characterization and theoretical calculations have helped disclose their electronic structure, as well as rationalize their associated magnetic and photophysical properties, spanning the chemical space of available molecular templates for cutting-edge applications in organic electronics and spintronics. 相似文献
23.
Guanqi Wang Dr. Yohann Moreau Dr. Florian Berthiol Dr. Christian Philouze Dr. Olivier Jarjayes Prof. Fabrice Thomas 《欧洲无机化学杂志》2023,26(15):e202300223
The copper and nickel complexes of two tetradentate ligands derived from bis(aminophenol) and bis(phenol) architectures connected by an oxamate linker were isolated. Depending on the metal and ligand, the complex is isolated with either an intact (deprotonated) ligand ( 12− ), one-electron oxidized ligand ( 2− ) or quinone form ( 3 ). Surprisingly, the Mannich base is easier to oxidize than the amidophenol derivatives. The complexes were characterized by X-ray diffraction, cyclic voltammetry, UV-Vis-NIR and EPR spectroscopies. Complex 1 shows two reversible oxidation waves assigned to the successive iminosemiquinone/aminophenolate redox systems. Complex 2− shows an intense NIR feature, as well as an EPR signal at giso=2.043, consistent with a metallic contribution to the main ligand radical SOMO. Complex 3 shows the typical feature of an isolated Cu(II) complex. Spectro-electrochemistry coupled to DFT calculations demonstrate a ligand-centered oxidative redox chemistry for all the complexes. 相似文献
24.
Frontispiece: EPR Studies of the Binding Properties,Guest Dynamics,and Inner‐Space Dimensions of a Water‐Soluble Resorcinarene Capsule 下载免费PDF全文
25.
Insights into the Catalytic Activity of Nitridated Fibrous Silica (KCC‐1) Nanocatalysts from 15N and 29Si NMR Spectroscopy Enhanced by Dynamic Nuclear Polarization 下载免费PDF全文
Dr. Aany Sofia Lilly Thankamony Dr. Cédric Lion Dr. Frédérique Pourpoint Baljeet Singh Dr. Angel J. Perez Linde Dr. Diego Carnevale Prof. Geoffrey Bodenhausen Dr. Hervé Vezin Prof. Olivier Lafon Prof. Vivek Polshettiwar 《Angewandte Chemie (International ed. in English)》2015,54(7):2190-2193
Fibrous nanosilica (KCC‐1) oxynitrides are promising solid‐base catalysts. Paradoxically, when their nitrogen content increases, their catalytic activity decreases. This counterintuitive observation is explained here for the first time using 15N‐solid‐state NMR spectroscopy enhanced by dynamic nuclear polarization. 相似文献
26.
ortho‐, meta‐, and para‐Dihydroindenofluorene Derivatives as Host Materials for Phosphorescent OLEDs 下载免费PDF全文
Maxime Romain Sébastien Thiery Anna Shirinskaya Dr. Céline Declairieux Dr. Denis Tondelier Bernard Geffroy Dr. Olivier Jeannin Dr. Joëlle Rault‐Berthelot Dr. Rémi Métivier Dr. Cyril Poriel 《Angewandte Chemie (International ed. in English)》2015,54(4):1176-1180
This work reports the first structure–properties relationship study of ortho [2,1‐c]‐, meta [1,2‐a]‐, and para [1,2‐b]dihydroindenofluorenes, highlighting the influence of bridge rigidification on the electronic properties. This study has made it possible to devise an extended π‐conjugated molecule with both a high triplet state energy level and excellent thermal and morphological stability. As a proof of concept, dihydroindenofluorenes were used as the host in sky‐blue phosphorescent organic light‐emitting diodes (PhOLEDs) w ith high performance. 相似文献
27.
Andreu Presa Rosa F. Brissos Ana Belén Caballero Ivana Borilovic Dr. Luís Korrodi‐Gregório Prof. Ricardo Pérez‐Tomás Dr. Olivier Roubeau Prof. Patrick Gamez 《Angewandte Chemie (International ed. in English)》2015,54(15):4561-4565
The photoactivation of potential anticancer metal complexes is a hot topic of current research as it may lead to the development of more selective drugs. Photoactivated chemotherapy (PACT) with coordination compounds is usually based on a (photo)chemical reaction taking place at the metal center. Herein, a new strategy is exploited that consists of “photomodifying” a ligand coordinated to metal ions. Platinum(II) complexes from photoswitchable 1,2‐dithienylethene‐containing ligands have been prepared, which exhibit two interconvertible photoisomeric forms that present distinct DNA‐interacting properties and cytotoxic behaviors. 相似文献
28.
Dr. Damien Lhenry Dr. Manuel Larrouy Dr. Claire Bernhard Dr. Victor Goncalves Dr. Olivier Raguin Dr. Peggy Provent Dr. Mathieu Moreau Dr. Bertrand Collin Dr. Alexandra Oudot Dr. Jean‐Marc Vrigneaud Dr. François Brunotte Dr. Christine Goze Prof. Franck Denat 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):13091-13099
In molecular imaging, multimodal imaging agents can provide complementary information, for improving the accuracy of disease diagnosis or enhancing patient management. In particular, optical/nuclear imaging may find important preclinical and clinical applications. To simplify the preparation of dual‐labeled imaging agents, we prepared versatile monomolecular multimodal imaging probe (MOMIP) platforms containing both a fluorescent dye (BODIPY) and a metal chelator (polyazamacrocycle). One of the MOMIP was conjugated to a cyclopeptide (i.e., octreotide) and radiolabeled with 111In. In vitro and in vivo studies of the resulting bioconjugate were conducted, highlighting the potential of these BODIPY‐based bimodal probes. This work also confirmed that the biovector and/or the bimodal probes must be chosen carefully, due to the impact of the MOMIP on the overall properties of the resulting imaging agent. 相似文献
29.
Sequential Synthesis of 3 d–3 d, 3 d–4 d,and 3 d–5 d Hybrid Polyoxometalates and Application to the Electrocatalytic Oxygen Reduction Reactions 下载免费PDF全文
Dr. Guillaume Rousseau Shuangshuang Zhang Dr. Olivier Oms Dr. Anne Dolbecq Dr. Jérôme Marrot Dr. Rongji Liu Xinke Shang Prof. Guangjin Zhang Prof. Pierre Mialane 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):12153-12160
The Co7(AlePy)2 polyoxometalate, which encloses a {(PW9)2CoII7} core covalently bound to two free aminopyridine groups through bisphosphonate ligands ( AlePy ), has been isolated. It can be used as a precursor, allowing the synthesis of heterometallic hybrid compounds, as illustrated by the characterization of cobalt/zinc ( Co7(AlePyZn)2 ), cobalt/palladium ( Co7(AlePyPd)2 ), and cobalt/platinum ( Co7(AlePyPt)2 ) species. A composite based on the water‐insoluble precious metal‐free Co7(AlePyZn)2 compound and the low‐cost carbon material Vulcan XC‐72 has been selected as a cathode material ( Co7Zn/C ) for oxygen reduction reaction studies. The electrocatalytic performances of the Co7Zn/C hybrids were assessed at neutral and basic pH, showing that Co7Zn/C exhibits high selectivity for the four‐electron reduction of O2. Moreover, its durability is superior to that of a commercial Pt/C catalyst with 20 % loading. Also, comparative studies performed in the presence of methanol have indicated that Co7Zn/C has a much better tolerance to the crossover effect than Pt/C . Altogether, these results indicate for the first time that, even in neutral media, polyoxometalate/carbon composites can represent low‐cost oxygen reduction catalysts that can function stably, for a long time, and with high performance. 相似文献
30.
EPR Studies of the Binding Properties,Guest Dynamics,and Inner‐Space Dimensions of a Water‐Soluble Resorcinarene Capsule 下载免费PDF全文
Dr. Mehmet Menaf Ayhan Dr. Gilles Casano Dr. Hakim Karoui Prof. Antal Rockenbauer Dr. Valérie Monnier Dr. Micaël Hardy Prof. Paul Tordo Dr. David Bardelang Dr. Olivier Ouari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16404-16410
Nitroxide free radicals have been used to study the inner space of one of Rebek’s water‐soluble capsules. EPR and 1H NMR spectroscopy, ESI‐MS, and DFT calculations showed a preference for the formation of 1:2 complexes. EPR titrations allowed us to determine binding constants (Ka) in the order of 107 M ?2. EPR spectral‐shape analysis provided information on the guest rotational dynamics within the capsule. The interplay between optimum hydrogen bonding upon capsule formation and steric strain for guest accommodation highlights some degree of flexibility for guest inclusion, particularly at the center of the capsule where the hydrogen bond seam can be barely distorted or slightly disturbed. 相似文献