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971.
本文研究了UV固化纳米金属氧化物(ATO)粒径和涂布厚度与薄膜隔热性能的关系,比较了纳米涂层隔热膜与磁控溅射隔热膜的性能和特点。结果表明,光固化树脂单体等组分的官能度、纳米金属氧化物的用量和纳米材料粒径与涂层的隔热性能有密切关系,合理的材料组合制成的隔热膜隔热率可达到50%以上。两类隔热窗膜的对照测试显示,纳米涂层隔热膜具有高透高隔热和隔热性能稳定的特点,纳米涂层隔热膜湿热老化后红外线透过率变化只有5%左右。 相似文献
972.
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974.
Dr. Hewei Zhao Prof. Yujie Zhu Dr. Fengshi Li Dr. Rui Hao Dr. Shaoxiong Wang Prof. Lin Guo 《Angewandte Chemie (International ed. in English)》2017,56(30):8766-8770
Two-dimensional (2D) nanomaterials show unique electrical, mechanical, and catalytic performance owing to their ultrahigh surface-to-volume ratio and quantum confinement effects. However, ways to simply synthesize 2D metal oxide nanosheets through a general and facile method is still a big challenge. Herein, we report a generalized and facile strategy to synthesize large-size ultrathin 2D metal oxide nanosheets by using graphene oxide (GO) as a template in a wet-chemical system. Notably, the novel strategy mainly relies on accurately controlling the balance between heterogeneous growth and nucleation of metal oxides on the surface of GO, which is independent on the individual character of the metal elements. Therefore, ultrathin nanosheets of various metal oxides, including those from both main-group and transition elements, can be synthesized with large size. The ultrathin 2D metal oxide nanosheets also show controllable thickness and unique surface chemical state. 相似文献
975.
Kostiantyn Kulyk Valentyna Ishchenko Borys Palyanytsya Volodymyr Khylya Mykola Borysenko Tetiana Kulyk 《Journal of mass spectrometry : JMS》2010,45(7):750-761
The interactions between coumarins and the surface of fumed SiO2, CeO2/SiO2, TiO2/SiO2 and Al2O3/SiO2 were assessed by means of temperature‐programed desorption mass spectrometry. The different stages of the thermolysis of coumarin were identified and an analysis of the underlying reactions was performed. The kinetic parameters of the involved reactions were thus obtained. The decomposition of thiazolyl‐substituted coumarins was found to proceed through a ‘thiazole–thiazine’ ring expansion in the adsorbed state. A linear correlation between the sigma constants (Σσ) of the coumarin substituents and the activation energy of CO2 formation was obtained. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
976.
Mihaela Jitianu Marina Bãlãsoiu Maria Zaharescu Andrei Jitianu Alexandru Ivanov 《Journal of Sol-Gel Science and Technology》2000,19(1-3):453-457
Hydrotalcite is an anionic clay mineral (layered double hydroxide) whose general formula is [M(II)1–x
M(III)
x
(OH)2]
x+X
x/n
n–
·mH2O. Anionic clays with a hydrotalcite-type are widely used as useful precursors of multicomponent catalysts. Hydrotalcites with Ni/Al molar ratio 2.5 have been synthesised both by the coprecipitation method, starting with nickel and aluminium nitrates and by the sol-gel method, using nickel acetylacetonate and aluminium isopropylate as precursors. The NiO-Al2O3 oxidic forms have been obtained by the thermal treatment of the precursors at 450°C and 900°C, respectively, and were characterised by DTA, XRD, IR spectroscopy and temperature programmed reduction (TPR). TPR clearly demonstrated a higher reducibility of the oxidic forms derived from the sol-gel synthesised precursors. 相似文献
977.
Consideration of the Hirshfeld surfaces for some simple inclusion complexes of p-t-butyltetrathiacalix[4]arene and a number of its metal ion derivatives indicates that a bound metal ion can significantly influence the nature of the interactions between the included molecule and the cavity. These interactions do, however, vary with the degree of deprotonation of the calixarene, the particular nature of the bound metal ion and, in some cases, with the extent of exo-cavity interactions of the included species. The possible influences of inclusion interactions on the catalytic activity of metallocalixarenes are assessed. 相似文献
978.
Prof. Hiroki Taniguchi Dr. Akihide Kuwabara Dr. Jungeun Kim Younghun Kim Dr. Hiroki Moriwake Prof. Sungwng Kim Takuya Hoshiyama Tsukasa Koyama Prof. Shigeo Mori Prof. Masaki Takata Prof. Hideo Hosono Prof. Yoshiyuki Inaguma Prof. Mitsuru Itoh 《Angewandte Chemie (International ed. in English)》2013,52(31):8088-8092
979.
980.
Annabel Rae Keelan M. Byrne Scott A. Brown Dr. Alan R. Kennedy Dr. Tobias Krämer Prof. Robert E. Mulvey Dr. Stuart D. Robertson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(18):e202104260
Arylmethyl anions allow alkali-metals to bind in a σ-fashion to the lateral carbanionic centre or a π-fashion to the aryl ring or in between these extremities, with the trend towards π bonding increasing on descending group 1. Here we review known alkali metal structures of diphenylmethane, fluorene, 2-benzylpyridine and 4-benzylpyridine. Next, we synthesise Li, Na, K monomers of these diarylmethyls using polydentate donors PMDETA or Me6TREN to remove competing oligomerizing interactions, studying the effect that two aromatic rings has on negative charge (de)localisation via NMR, X-ray crystallographic and DFT studies. Diphenylmethyl and fluorenyl anions maintain C(H)−M interactions regardless of alkali-metal, although the adjacent arene carbons engage in interactions with larger alkali-metals. Introducing a nitrogen atom into the ring (at the 2- or 4-position) encourages relocalisation of negative charge away from the deprotonated carbon and onto nitrogen. Phenyl(2-pyridyl)methyl moves from an enamide formation at one extremity (lithium) to an aza-allyl formation at the other extremity (potassium), while C- or N-coordination modes become energetically viable for Na and K phenyl(4-pyridyl)methyl complexes. 相似文献