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61.
62.
Tsuchiya T Wakahara T Lian Y Maeda Y Akasaka T Kato T Mizorogi N Nagase S 《The journal of physical chemistry. B》2006,110(45):22517-22520
A preferential extraction of endohedral metallofullerenes (EMFs) from carbon soot through the use of reduction in the extraction process and a convenient isolation of endohedral metallofullerene anions (EMFs(-)) and empty fullerenes utilizing their difference in solubility are accomplished. EMFs are easily isolated by one-stage high-performance liquid chromatography after chemical oxidation of the extracted endohedral EMFs(-). 相似文献
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We completely determine the moduli space M(N,k) of k vortices in U(N) gauge theory with N Higgs fields in the fundamental representation. Its open subset for separated vortices is found as the symmetric product (CxCP(N-1))k/(see text)k. Orbifold singularities of this space correspond to coincident vortices and are resolved resulting in a smooth moduli manifold. The relation to K?hler quotient construction is discussed. 相似文献
65.
Kazuyuki Akasaka 《高压研究》2013,33(4):453-457
NMR experiments at variable pressure reveal a wide range of conformation of a globular protein spanning from within the folded ensemble to the fully unfolded ensemble, herewith collectively called “high-energy conformers”. The observation of “high-energy conformers” in a wide variety of globular proteins has led to the “volume theorem”: the partial molar volume of a protein decreases with the decrease in its conformational order. Since “high-energy conformers” are intrinsically more reactive than the basic folded conformer, they could play decisive roles in all phenomena of proteins, namely function, environmental adaptation and misfolding. Based on the information on high-energy conformers and the rules on their partial volume in its monomeric state and amyloidosis, one may have a general view on what is happening on proteins under pressure. Moreover, one may even choose a high-energy conformer of a protein with pressure as variable for a particular purpose. Bridging “high-energy conformers” to macroscopic pressure effects could be a key to success in pressure application to biology, medicine, food technology and industry in the near future. 相似文献
66.
In‐Depth Understanding of the Chemical Properties of Rarely Explored Carbide Cluster Metallofullerenes: A Case Study of Sc2C2@C3v(8)‐C82 that Reveals a General Rule
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Wenting Cai Muqing Chen Lipiao Bao Dr. Yunpeng Xie Prof. Dr. Takeshi Akasaka Prof. Dr. Xing Lu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(8):3449-3454
The chemical properties of carbide‐cluster metallofullerenes (CCMFs) remain largely unexplored, although several new members of CCMFs have been discovered recently. Herein, we report the reaction between Sc2C2@C3v(8)‐C82, which is viewed as a prototypical CCMF because of its high abundance, and 3‐triphenylmethyl‐5‐oxazolidinone ( 1 ) to afford the corresponding pyrrolidino derivative Sc2C2@C3v(8)‐C82(CH2)2NTrt ( 2 ; Trt=triphenylmethyl). Single‐crystal X‐ray crystallography studies of 2 revealed that the reaction takes place at a [6,6]‐bond junction, which is directly over the encapsulated C2 unit and is far from either of the two scandium atoms. On the basis of theoretical calculations and by considering previously reports, we have found that a hexagonal carbon ring on the cage of Sc2C2@C3v(8)‐C82 is highly reactive toward different reagents due to the overlap of high p‐orbital axis vector (POAV) angles and large LUMO coefficients. We propose that this highly concentrated area of reactivity is generated by the encapsulation of the Sc2C2 cluster because this region is absent from the empty fullerene C3v(8)‐C82. Moreover, the absorption and electrochemical results confirm that derivative 2 is more stable than pristine Sc2C2@C3v(8)‐C82, thus illuminating its potential applications. 相似文献
67.
Prof. Dr. Michio Yamada Prof. Dr. Takeshi Akasaka Prof. Dr. Shigeru Nagase 《Angewandte Chemie (International ed. in English)》2018,57(41):13394-13405
The awesome allotropy of carbon yields innumerable topologically possible cage structures of molecular carbon. This field is also related to endohedral metallofullerenes constructed by metal‐atom encapsulation. Stable and soluble empty fullerenes and endohedral metallofullerenes are available in pure form in macroscopic amounts from carbon arc production or other physical processes followed by extraction and subsequent chromatographic separation. However, many other unidentified fullerene species, which must be reactive and insoluble in their pristine forms, remain in soot. These “missing” species must have extremely small HOMO–LUMO gaps and may have unconventional cage structures. Recent progress in this field has demonstrated that reactive fullerenes can be salvaged by exohedral derivatization, which can stabilize the reactive carbon cages. This concept provides a means of preparing macroscopic amounts of unconventional fullerenes as their derivatives. 相似文献
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69.
Tsukasa Nakahodo Midori O. Ishitsuka Yutaka Maeda Hisashi Fujihara Takeshi Akasaka 《Tetrahedron letters》2008,49(14):2302-2305
The photochemical reaction of C60 with selenium-containing bicyclooctanes affords for the first time the selenylfullerenes. The derivatives were characterized by mass, UV-vis absorption, NMR spectroscopy, and X-ray crystallographic analysis. 相似文献
70.
Shintaro Kohata Prof. Hajime Nakanotani Prof. Youhei Chitose Prof. Takuma Yasuda Prof. Youichi Tsuchiya Prof. Chihaya Adachi 《Angewandte Chemie (International ed. in English)》2023,62(44):e202312326
Photon-upconversion in organic molecular systems is one of the promising technologies for future energy harvesting systems because these systems can generate excitons that possess higher energy than excitation energy. The photon-upconversion caused by absorbing ambient heat as additional energy is particularly interesting because it could ideally provide a light-driving cooling system. However, only a few organic molecular systems have been reported. Here, we report the anti-Stokes photoluminescence (ASPL) derived from hot-band absorption in a series of multi-resonance-type thermally-activated delayed fluorescence (MR-TADF) molecules. The MR-TADF molecules exhibited an anti-Stokes shift of approximately 0.1 eV with a high PL quantum yield in the solution state. The anti-Stokes shift corresponded well to the 1–0 vibration transition from the ground state to the excited singlet state, and we further evaluated a correlation between the activation energy for the ASPL intensity and the TADF process. Our demonstration underlines that MR-TADF molecules have become a novel class of ASPL materials for various future applications, such as light-driving cooling systems. 相似文献