全文获取类型
收费全文 | 529篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
化学 | 353篇 |
晶体学 | 4篇 |
力学 | 18篇 |
数学 | 74篇 |
物理学 | 88篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 16篇 |
2021年 | 31篇 |
2020年 | 19篇 |
2019年 | 24篇 |
2018年 | 16篇 |
2017年 | 12篇 |
2016年 | 20篇 |
2015年 | 20篇 |
2014年 | 17篇 |
2013年 | 41篇 |
2012年 | 32篇 |
2011年 | 32篇 |
2010年 | 24篇 |
2009年 | 15篇 |
2008年 | 27篇 |
2007年 | 35篇 |
2006年 | 29篇 |
2005年 | 18篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 20篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有537条查询结果,搜索用时 15 毫秒
101.
Dandan Chen Dr. Dariusz W. Szczepanik Prof. Jun Zhu Prof. Miquel Solà 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(57):12964-12971
Species with adaptive aromaticity are aromatic in the ground and lowest-lying triplet excited states and they have normally intermediate singlet-triplet gaps. Few examples of compounds with adaptive aromaticity are known to date, including 16-valence-electron (16e) metallapentalenes. A sweeping search could be conducted to discover new members of this group, but efficient designs with an explicit strategy would facilitate the quest for new members of this elusive family. Density functional theory calculations and aromaticity evaluations have been performed to reveal the nature of triplet-state aromaticity in 16e metallapentalenes. Our results show that coordination of strong σ- or π-donor ligands helps achieving adaptive aromaticity of 16e metallapentalenes by means of a spin delocalization mechanism. These results have important implications for understanding the unusual properties of the organometallic adaptive aromatics, leading the way to efficient design of new compounds with tunable singlet-triplet gaps. 相似文献
102.
Król Mariusz Staszuk Marcin Mikuszewski Tomasz Kuc Dariusz 《Journal of Thermal Analysis and Calorimetry》2018,134(1):333-341
Journal of Thermal Analysis and Calorimetry - The effect of 2 mass% rare earth elements (RE) as in mischmetal state on the structure, thermal behaviour and mechanical properties of... 相似文献
103.
ukasz Gondek Dariusz Kaczorowski Andrzej Szytua 《Solid State Communications》2009,149(47-48):2181-2184
Magnetic, electrical transport and heat capacity measurements have been performed on polycrystalline sample of the compound TmRu2Si2, which crystallizes with the tetragonal ThCr2Si2-type crystal structure. The results show paramagnetic behaviour down to 0.3 K, at variance with the literature data. On the basis of the collected data, possible origins of non-magnetic behaviour are discussed. Mixed valence of Tm ions or hybridisation between Tm 4f and Ru 4d states are the most probable reasons for paramagnetic behaviour of the TmRu2Si2. 相似文献
104.
Dr. Dariusz G. Piekarski Pascal Steinforth Dr. Melania Gómez-Martínez Dr. Julia Bamberger Florian Ostler Prof. Dr. Monika Schönhoff Prof. Dr. Olga García Mancheño 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(72):17598-17603
H-bond donor catalysts able to modulate the reactivity of ionic substrates for asymmetric reactions have gained great attention in the past years, leading to the development of cooperative multidentate H-bonding supramolecular structures. However, there is still a lack of understanding of the forces driving the ion recognition and catalytic performance of these systems. Herein, insight into the cooperativity nature, anion binding strength, and folding mechanism of a model chiral triazole catalyst is presented. Our combined experimental and computational study revealed that multi-interaction catalysts exhibiting weak binding energies (≈3–4 kcal mol−1) can effectively recognize ionic substrates and induce chirality, while strong dependencies on the temperature and solvent were quantified. These results are key for the future design of catalysts with optimal anion binding strength and catalytic activity in target reactions. 相似文献
105.
Sadlej-Sosnowska Nina Ocios-Bębenek Agnieszka Dobrowolski Jan Cz. Boczar Dariusz 《Structural chemistry》2022,33(2):479-490
Structural Chemistry - Cumulenes and polyynes have the potential to be applied as linear, sp-hybridized, one-dimensional all-carbon nanowires in molecular electronics and optoelectronics. The... 相似文献
106.
Aleksandra Kawczyk-Krupka Dorota Bartusik-Aebisher Wojciech Latos Grzegorz Cieślar Karolina Sieroń Sebastian Kwiatek Piotr Oleś Beata Kwiatek David Aebisher Magdalena Krupka Rafał Wiench Dariusz Skaba Marcin Olek Jacek Kasperski Zenon Czuba Aleksander Sieroń 《Photochemistry and photobiology》2020,96(3):539-549
The purpose of this review is to present an overview of the development of photodiagnostic and photodynamic therapy (PDD and PDT) techniques in Poland. The paper discusses the principles of PDD, including fluorescent techniques in determining precancerous conditions and cancers of the skin, digestive tract, bladder and respiratory tract. Methods of PDT of cancer will be discussed and the current state of knowledge as well as future trends in the development of photodynamic techniques will be presented, including the possibility of using photodynamic antimicrobial therapy. Research pioneers in photodynamic medicine such as Thomas Dougherty are an inspiration for the development of methods of PDD and PDT in our Clinic. The Center for Laser Diagnostics and Therapy in Bytom, Poland, promotes the propagation of PDD and PDT through the training of clinicians and raising awareness among students in training and the general public. Physicians at the Center are engaged in photomedical research aimed at clinical implementation and exploration of new avenues in photomedicine while optimizing existing modalities. The Center promotes dissemination of clinical results from a wide range of topics in PDD and PDT and serving as representative authorities of photodynamic medicine in Poland and Europe. 相似文献
107.
A topological proof is given that real compositions algebras of finite dimension greater than one are algebraically closed under polynomial equations with a tame tail. 相似文献
108.
We consider the notion of prediction functions (or predictors) studied before in the context of randomness and stochasticity by Ko, and later by Ambos‐Spies and others. Predictor is a total computable function which tries to predict bits of some infinite binary sequence. The prediction error is defined as the limit of the number of incorrect answers divided by the number of answers given so far. We discuss indefiniteness of prediction errors for weak 1‐generics and show that this phenomenon affects certain c.e. sequences as well. On the other hand, a notion of optimal predictor is considered. It is shown that there is a sequence for which increasingly better predictors exist but for which no predictor is optimal. 相似文献
109.
110.
A simple method of analysing and localization of canonical molecular orbitals for particular chemical bond using the MO-resolved bond-order decomposition scheme is presented. An alternative definition of classical bond order orbitals is provided and links to communication theory of the chemical bond are outlined and briefly discussed. The introduced procedure of decomposition of quadratic bond orders allows one to analyse two- as well as three- center chemical bonds within the framework of the same theory. 相似文献