全文获取类型
收费全文 | 460篇 |
免费 | 49篇 |
国内免费 | 1篇 |
专业分类
化学 | 407篇 |
力学 | 5篇 |
数学 | 30篇 |
物理学 | 68篇 |
出版年
2024年 | 3篇 |
2023年 | 14篇 |
2022年 | 14篇 |
2021年 | 18篇 |
2020年 | 32篇 |
2019年 | 32篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 31篇 |
2015年 | 32篇 |
2014年 | 34篇 |
2013年 | 27篇 |
2012年 | 44篇 |
2011年 | 37篇 |
2010年 | 22篇 |
2009年 | 13篇 |
2008年 | 25篇 |
2007年 | 19篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 6篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1943年 | 1篇 |
1939年 | 1篇 |
1931年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有510条查询结果,搜索用时 0 毫秒
501.
Dr. Giuseppe Antonio Elia Ulderico Ulissi Franziska Mueller Dr. Jakub Reiter Dr. Nikolaos Tsiouvaras Prof. Yang‐Kook Sun Prof. Bruno Scrosati Prof. Stefano Passerini Prof. Jusef Hassoun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(20):6808-6814
In this paper, we report an advanced long‐life lithium ion battery, employing a Pyr14TFSI‐LiTFSI non‐flammable ionic liquid (IL) electrolyte, a nanostructured tin carbon (Sn‐C) nanocomposite anode, and a layered LiNi1/3Co1/3Mn1/3O2 (NMC) cathode. The IL‐based electrolyte is characterized in terms of conductivity and viscosity at various temperatures, revealing a Vogel–Tammann–Fulcher (VTF) trend. Lithium half‐cells employing the Sn‐C anode and NMC cathode in the Pyr14TFSI‐LiTFSI electrolyte are investigated by galvanostatic cycling at various temperatures, demonstrating the full compatibility of the electrolyte with the selected electrode materials. The NMC and Sn‐C electrodes are combined into a cathode‐limited full cell, which is subjected to prolonged cycling at 40 °C, revealing a very stable capacity of about 140 mAh g?1 and retention above 99 % over 400 cycles. The electrode/electrolyte interface is further characterized through a combination of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) investigations upon cell cycling. The remarkable performances reported here definitively indicate that IL‐based lithium ion cells are suitable batteries for application in electric vehicles. 相似文献
502.
Huihui Xu Dr. Catherine Weetman Franziska Hanusch Prof. Shigeyoshi Inoue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202104042
Despite the notable progress in aluminium chalcogenides, their sulfur congeners have rarely been isolated under mild conditions owing to limited synthetic precursors and methods. Herein, facile isolation of diverse molecular aluminium sulfides is achievable, by the reaction of N-heterocyclic carbene-stabilized terphenyl dihydridoaluminium ( 1 ) with various thiation reagents. Different to the known dihydridoaluminium 1Tipp , 1 features balanced stability and reactivity at the Al center. It is this balance that enables the first monomeric aluminium hydride hydrogensulfide 2 , the six-membered cyclic aluminium polysulfide 4 and the five-membered cyclic aluminium polysulfide 6 to be isolated, by reaction with various equivalents of elemental sulfur. Moreover, a rare aluminium heterocyclic sulfide with Al−S−P five-membered ring ( 7 ) was obtained in a controlled manner. All new compounds were fully characterized by multinuclear NMR spectroscopy and elemental analysis. Their structures were confirmed by single-crystal X-ray diffraction studies. 相似文献
503.
Dr. Niels Zijlstra Fabian Dingfelder Dr. Bengt Wunderlich Dr. Franziska Zosel Dr. Stephan Benke Dr. Daniel Nettels Prof. Dr. Benjamin Schuler 《Angewandte Chemie (International ed. in English)》2017,56(25):7126-7129
To enable the investigation of low-affinity biomolecular complexes with confocal single-molecule spectroscopy, we have developed a microfluidic device that allows a concentrated sample to be diluted by up to five orders of magnitude within milliseconds, at the physical limit dictated by diffusion. We demonstrate the capabilities of the device by studying the dissociation kinetics and structural properties of low-affinity protein complexes using single-molecule two-color and three-color Förster resonance energy transfer (FRET). We show that the versatility of the device makes it suitable for studying complexes with dissociation constants from low nanomolar up to 10 μm , thus covering a wide range of biomolecular interactions. The design and precise fabrication of the devices ensure simple yet reliable operation and high reproducibility of the results. 相似文献
504.
Xuan-Xuan Zhao Prof. Dr. Tibor Szilvási Franziska Hanusch Prof. Dr. Shigeyoshi Inoue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(64):15914-15917
A rare three-coordinate germanone [IPrN]2Ge=O (IPrN=bis(2,6-diisopropylphenyl)imidazolin-2-imino) was successfully isolated. The germanone has a rather high thermal stability in arene solvent, and no detectable change was observed at 80 °C for at least one week. However, high thermal stability of [IPrN]2Ge=O does not prevent its reactivity toward small molecules. Structural analysis and initial reactivity studies revealed the highly polarized nature of the terminal Ge=O bond. Besides, the addition of phenylacetylene, as well as O-atom transfer with 2,6-dimethylphenyl isocyanide make it a mimic of nucleophilic transition-metal oxides. Mechanism for O-atom transfer reaction was investigated via DFT calculations, which revealed that the reaction proceeds via a [2+2] cycloaddition intermediate. 相似文献
505.
Franziska Karcher Matthias Uhl Tanja Geng Timo Jacob Rolf Schuster 《Angewandte Chemie (International ed. in English)》2023,62(22):e202301253
The formation of an appropriate solid electrolyte interphase (SEI) at the anode of a sodium battery is crucially dependent on the electrochemical stability of solvent and electrolyte at the redox potential of Na/Na+ in the respective system. In order to determine entropic contributions to the relative stability of the electrolyte solution, we measure the reaction entropy of Na metal deposition for diglyme (DG) and propylene carbonate (PC) based electrolyte solutions by electrochemical microcalorimetry at single electrodes. We found a large positive reaction entropy for Na+ deposition in DG of ΔR 234 J mol−1 K−1 (c.f.: ΔR 83 J mol−1 K−1), which signals substantial entropic destabilization of Na+ in DG by about 0.73 eV, thus increasing the stability of solvent and electrolyte relative to Na+ reduction. We attribute this strong entropic destabilization to a highly negative solvation entropy of Na+, due to the low dielectric constant and high freezing entropy of DG. 相似文献
506.
507.
508.
Franziska Weichelt Mario Beyer Rico Emmler Roman Flyunt Evelin Beyer Michael Buchmeiser 《Macromolecular Symposia》2011,301(1):23-30
Summary: Nano-sized zinc oxide (ZnO) was chosen as a suitable candidate for the UV-protection of coatings. ZnO-based acrylate coatings were applied to polycarbonate plates, glass plates and impregnated wood. Coated samples were artificially weathered (Xenon test) for at least 1500 hours and studied with regards to their optical and mechanical properties, such as color shifts (yellowing), as well as to changes in brightness, transparency or hydrophobicity. The prepared wood coatings showed reduced yellowing and improved optical properties. 相似文献
509.
In this contribution, the numerical modeling of electro-viscoelastic material is considered. The electro-mechanical problem formulated in terms of a symmetrized stress tensor is extended to a viscoelastic material model. For the incorporation of the viscosity model, the logarithmic strain space setting is utilized which mimics the small strain setting. Therefore a rheological model for viscosity from the geometrically linear theory can be used. Numerical examples for a typical uniaxial tensile test show the capability of the method to demonstrate typical relaxation and creep behavior. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
510.
Electrostatic self‐assembly can be used to form supramolecular vesicles in aqueous solution. Vesicles consist of cationic G8 poly(amidoamine) dendrimers and the trivalent sulfonate dye Ar27. No classical amphiphiles are present but the interplay of electrostatics, π–π interaction and geometric factors influences the structure formation. Labeled guest molecules, both small molecules and peptides, can be included inside these vesicles and vesicles imaged by fluorescence techniques. The structure was studied by dynamic and static light scattering, small‐angle neutron scattering, confocal laser scanning microscopy, and fluorescence correlation spectroscopy. The study indicates the prospect of constructing functional nanoobjects by the self‐assembly of charged molecules in aqueous solution.