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排序方式: 共有252条查询结果,搜索用时 15 毫秒
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The π‐Back‐Bonding Modulation and Its Impact in the Electronic Properties of CuII Antineoplastic Compounds: An Experimental and Theoretical Study 下载免费PDF全文
Juan Carlos García‐Ramos Dr. Rodrigo Galindo‐Murillo Araceli Tovar‐Tovar Ana Luisa Alonso‐Saenz Virginia Gómez‐Vidales Dr. Marcos Flores‐Álamo Dr. Luis Ortiz‐Frade Dr. Fernando Cortes‐Guzmán Dr. Rafael Moreno‐Esparza Prof. Antonio Campero Prof. Lena Ruiz‐Azuara 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13730-13741
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The theoretical knowledge about the zinc-zinc bond has been recently expanded after the proposal of a zinc-zinc double bond in several [Zn2(L)4] compounds (Angew. Chem. Int. Ed. 2017 , 56, 10151-10155). Prompted by these results, we have selected the [Zn2(CO)4] species, isolobally related to ethylene, and theoretically investigated the possible η2-Zn2-coordination to several first-row transition metal fragments. The [Zn2(CO)4] coordination to the metal fragment produces an elongation of the dizinc bond and a concomitant pyramidalization of the [Zn(CO)2] unit. These structural parameters are indicative of π-backdonation from the metal to the coordinated dizinc moiety, as occurred with ethylene ligand. A quantum theory of atoms in molecules study of the Zn Zn bond shows a decrease of ρBCP, ∇2ρBCP ∫Zn∩Znρ and delocalization indexes δ(Zn,Zn), relative to corresponding values in the parent [Zn2(CO)4] molecule. The Zn Zn and M Zn bonds in these [(η2-Zn2(CO)4)M(L)n] complexes can be described as shared interactions with an important covalent component where the Zn Zn bond is preserved, albeit weakened, upon coordination. 相似文献
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Peter T. Ndifon Moise O. Agwara Awawou G. Paboudam Divine M. Yufanyi Jean Ngoune Agustín Galindo Eleuterio Álvarez Aminou Mohamadou 《Transition Metal Chemistry》2009,34(7):745-750
A novel one-dimensional zigzag coordination polymer, dinitrodiaqua-bis(hexamethylenetetramine)cobalt(II) was synthesised and
characterised, and the structure was determined by single-crystal X-ray diffraction. The compound has a chain structure with
each cobalt atom covalently bonded to two nitrate ions, two water molecules and two HMTA molecules, giving a slightly distorted
octahedral geometry about the cobalt atom. Each HMTA ligand uses two of its N atoms to bond to two cobalt atoms giving an
approximately bent Co–HMTA–Co configuration. Each chain is hydrogen bonded through OH···N and OH···O interactions with neighbouring
chains leading to an overall polymer structure. Thermal studies show significant mass loss corresponding to the loss of the
coordinated water molecules and the decomposition of both the nitrate ions and the HMTA. 相似文献
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Matthew Herbert Francisco Montilla Raquel Moyano Antonio Pastor Eleuterio Álvarez Agustín Galindo 《Polyhedron》2009,28(18):3929-3934
Commercially available molybdenum(VI) compounds, including molybdenum trioxide, were successfully employed as catalyst precursors in the epoxidation of olefins with urea–hydrogen peroxide adduct (UHP) in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [C4mim][PF6]. After oxidation, the corresponding epoxides were isolated by extraction with diethyl ether. Additionally the ionic liquid–catalyst mixture was recycled and reused in further catalytic cycles. The catalytic species is assumed to be an oxodiperoxomolybdenum species which forms in situ. A representative complex of this type was thus isolated and characterised. Reaction of excess 4-methylpyridine-1-oxide (4-MepyO) with MoO3 dissolved in aqueous hydrogen peroxide afforded [Mo(O)(O2)2(4-MepyO)2]·H2O (1) as yellow crystals. Compound 1, an active epoxidation catalyst, was subsequently characterised and its structure determined by X-ray crystallography. 相似文献
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Said A. Farha Al-Said Reda Hassanien Jennifer Hannant Miguel A. Galindo Stela Pruneanu Andrew R. Pike Andrew Houlton Benjamin R. Horrocks 《Electrochemistry communications》2009,11(3):550-553
Ag nanowires and nanoparticles have been formed on hybrid λ-DNA/conducting polymer templates. The strong, but non-covalent, interaction of the conducting polymer with the double helix allowed us to incorporate chemical functionalities (alkynyl) into the DNA/conducting polymer strands by synthesis of functional monomers. Oxidative polymerisation of alkynyl-thienylpyrrole in the presence of λ-DNA produced conductive nanowires bearing alkyne groups; we show, using a combination of AFM, cAFM and EFM phase measurements that the alkyne functionality strong influences the subsequent templating reaction of Tollens’ reagent to produce uniform conductive nanowires comprised of many connected Ag clusters. 相似文献
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Christophe Galindo Emmanuel BeaudoinDidier Gigmes Denis Bertin 《Journal of chromatography. A》2009,1216(47):8386-8390
We propose a fast, reliable chromatographic method to determine the grafting yield of a Polybutadiene-graft-Polystyrene (PB-g-PS) copolymer synthesized in our laboratory for High Impact Polystyrene applications. We used Liquid Chromatography at Critical Conditions of PS to separate non-grafted PS from graft product and ungrafted PB. Separation between grafted copolymer and non-grafted PS was very efficient and thanks to linearity of UV-detector response, we could quantify the amount of grafted PS in the copolymer, as well as calculate the grafting yield. Results shown here are for DOW BR1202D high-cis PB and BASF CB529T low-cis PB, Luperox TBIC M75 initiator at 8 × 10−4 mol L−1 and 125 °C reaction temperature. 相似文献