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891.
Dr. Takahito Watanabe Yumi Kasai Prof. Dr. Hiromi Tobita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(59):13491-13495
Reaction of N-heterocyclic carbene (NHC)-stabilized PGeP-type germylene Ge{o-(PiPr2)C6H4}2⋅MeIiPr ( 1 ) (MeIiPr=1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) with Ni(cod)2 gave pincer germylene complex Ni[Ge{o-(PiPr2)C6H4}2](MeIiPr) ( 2 ), in which the Ge center of 2 is significantly pyramidalized. Theoretical calculation on 2 predicted the ambiphilicity of the germanium center, which was confirmed by reactivity studies. Thus, complex 2 reacted with both Lewis base MeIMe (MeIMe=1,3,4,5-tetramethylimidazol-2-ylidene) and Lewis acid BH3⋅SMe2 at the germanium center to afford the adducts Ni[Ge{o-(PiPr2)C6H4}2⋅MeIMe](MeIiPr) ( 3 ) and Ni[Ge{o-(PiPr2)C6H4}2⋅BH3](MeIiPr) ( 4 ), respectively. Furthermore, the former was slowly converted to dinuclear complex Ni2[Ge{o-(PiPr2)C6H4}2]2(MeIMe)2 ( 5 ) at room temperature. Complex 5 can be regarded as a dimer of the MeIMe analog of 2 with a Ni-Ge-Ge-Ni linkage. 相似文献
892.
Dr. Manoj B. Gawande Dr. Anuj K. Rathi Prof. Dr. Paula S. Branco Dr. Isabel D. Nogueira Prof. Dr. Alexandre Velhinho Dr. Janhavi J. Shrikhande Dr. Utkarsha U. Indulkar Prof. Dr. Radha V. Jayaram Dr. C. Amjad A. Ghumman Dr. Nenad Bundaleski Prof. Orlando M. N. D. Teodoro 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(40):12628-12632
893.
《化学:亚洲杂志》2017,12(3):278-282
A combined kinetic and theoretical study was conducted in order to clarify the details on the reaction mechanism for Ni0/It Bu‐catalyzed intramolecular alkene hydroacylation. The results confirm the hypothesis that this intramolecular hydroacylation proceeds through an oxanickelacycle key intermediate. 相似文献
894.
Matthew K. Nielsen Benjamin J. Shields Junyi Liu Dr. Michael J. Williams Dr. Michael J. Zacuto Prof. Abigail G. Doyle 《Angewandte Chemie (International ed. in English)》2017,56(25):7191-7194
We report a redox-neutral formylation of aryl chlorides that proceeds through selective 2-functionalization of 1,3-dioxolane through nickel and photoredox catalysis. This scalable benchtop approach provides a distinct advantage over traditional reductive carbonylation in that no carbon monoxide, pressurized gas, or stoichiometric reductant is employed. The mild conditions give unprecedented scope from abundant and complex aryl chloride starting materials. 相似文献
895.
In this work, a green approach is reported for efficient synthesis of biologically active tetrazole and pyranopyrazole derivatives in the presence of Cu-Cytosine@MCM-41 and Ni-Cytosine@MCM-41 (copper (II) and nickel (II) catalyst on the modified MCM-41 using cytosine). The synthesis of tetrazoles and pyranopyrazoles in the presence of these catalysts was performed in green solvents such as water or poly (ethylene glycol) (PEG). All products were obtained in high TOF (turnover frequency) numbers in the presence of these catalysts, which indicate the high efficiency of these catalysts in the synthesis of tetrazole and pyranopyrazole derivatives. The prepared catalysts were characterized by various techniques such as BET, TGA, XRD, FT-IR, SEM, EDS, WDX, TEM, and AAS. Mesoporous structure of these catalysts was confirmed by nitrogen adsorption–desorption isotherms. These catalysts can be recovered and reused for several runs without significant change in their catalytic activity or metal capacity. The recovered catalysts have been characterized by XRD, SEM, EDS, WDX, FT-IR and AAS techniques, by which their heterogeneous nature has been confirmed. 相似文献
896.
897.
Immobilization of nickel ions onto the magnetic nanocomposite based on cross‐linked melamine groups: Effective heterogeneous catalyst for N‐Arylation of Arylboronic acids 下载免费PDF全文
Ali Pourjavadi Nahid Keshavarzi Firouz Matloubi Moghaddam Seyed Hassan Hosseini 《应用有机金属化学》2018,32(2)
A new magnetic heterogeneous catalyst was synthesized by immobilization of nickel ions onto a cross‐linked polymeric nanocomposite composed of cyanuric chloride, ethylenediamine and functionalized magnetic nanoparticles. The resulting nitrogen rich support was capable of adsorbing large amounts of nickel ions (1.20 mmol g?1). The synthesized catalyst was characterized using AAS, TEM, FT‐IR, EDX, TGA, SEM, BET and XRD techniques. The performance of the prepared catalyst was investigated in the C‐N coupling of arylamines with aryl boronic acids. The reaction was carried out under a mild condition and good to moderate to good yields of products was obtained using only 5.0 mol% of the catalyst. The catalyst was easily recovered and reused for at least 7 times without any significant loss of its activity. 相似文献
898.
Recyclable and reusable NiCl2(PPh3)2/CuI/PEG‐400/H2O system for the sonogashira coupling reaction of aryl iodides with alkynes 下载免费PDF全文
A stable and highly efficient NiCl2(PPh3)2/CuI/PEG‐400/H2O catalytic system for the Sonogashira reaction has been developed. In the presence of NiCl2(PPh3)2 and CuI, the coupling reaction of aryl iodides with terminal alkynes was carried out smoothly in a mixture of poly(ethylene glycol) (PEG‐400) and water at 100°C with K2CO3 as base to afford a variety of arylacetylenes in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether, and the NiCl2(PPh3)2/CuI/PEG‐400/H2O system could be easily recycled and reused six times without significant loss of catalytic activity. Our system not only avoids the use of easily volatile organic solvents but also solves the basic problem of catalyst reuse. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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900.