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41.
Yuto Suzuki Mario Gutirrez Senri Tanaka Eduardo Gomez Norimitsu Tohnai Nobuhiro Yasuda Nobuyuki Matubayasi Abderrazzak Douhal Ichiro Hisaki 《Chemical science》2021,12(28):9607
The library of isostructural porous frameworks enables a systematic survey to optimize the structure and functionality of porous materials. In contrary to metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), a handful of isostructural frameworks have been reported for hydrogen-bonded organic frameworks (HOFs) due to the weakness of the bonds. Herein, we provide a rule-of-thumb to develop isostructural HOFs, where we demonstrate the construction of the third and fourth generation of isostructural HAT-based HOFs (TolHAT-1 and ThiaHAT-1) by considering three important structural factors, that are (1) directional H-bonding, (2) shape-fitted docking of the HAT core, and (3) modulation of peripheral moieties. Their structural and photo-physical properties including HCl vapor detection are presented. Moreover, TolHAT-1, ThiaHAT-1, and other isostructural HOFs (CPHAT-1 and CBPHAT-1) were thoroughly compared from the viewpoints of structures and properties. Importantly, molecular dynamics (MD) simulation proves to be rationally capable of evaluating the stability of isostructural HOFs. These results can accelerate the development of various isostructural molecular porous materials.The library of isostructural porous frameworks enables a systematic survey to optimize the structure and functionality of porous materials. 相似文献
42.
Elaine Tsui Anthony J. Metrano Yuto Tsuchiya Prof. Robert R. Knowles 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):11943-11947
We report a catalytic, light-driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible-light irradiation in the presence of an IrIII-based photoredox catalyst, a Brønsted base catalyst, and a hydrogen-atom transfer (HAT) co-catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct homolytic activation of alcohol O−H bonds through a proton-coupled electron-transfer mechanism. This method exhibits a broad substrate scope and high functional-group tolerance, and it accommodates a diverse range of alkene substitution patterns. Results demonstrating the extension of this catalytic system to carboetherification reactions are also presented. 相似文献
43.
Yuto Kurasaki Yasuhito Suzuki Akikazu Matsumoto 《Journal of polymer science. Part A, Polymer chemistry》2020,58(7):923-931
We carried out the thermal curing of the copolymers of N-allylmaleimide (AMI) and 2-ethylhexyl acrylate (2EHA) using 1,3,4,6-tetra(2-mercaproethyl)glycoluril ( G1 ), 1,3,4,6-tetra(3-mercaptopropyl)glycoluril ( G2 ), 1,3,4,6-tetraallylglycoluril ( G3 ), triallylisocyanurate (TAIC), and pentaerythritol tetrakis(3-mercaptobutyrate) (PEMB) as the crosslinkers. Based on the results for the analysis of thiol–ene reactions monitored by IR spectroscopy, it was confirmed that the curing rate significantly depended on the combination of the used crosslinkers. The insoluble fraction after curing was more than 90% for the systems using the glycoluril crosslinkers, while the conversion of the allyl groups was suppressed due to the rigid structure of these crosslinkers. The heat resistance and the mechanical properties of the crosslinked polymers were investigated by thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and mechanical tensile tests. For the products cured using the glycoluril crosslinkers, the glass transition temperature (Tg) and the maximum temperature of thermal decomposition (Tmax) were 54–59 °C and 395–409 °C, respectively, being higher than those for the cured product prepared with PEMB and TAIC as the conventional crosslinkers. The elasticity (75–139 MPa), the maximum strength (3.0–4.1 MPa), and the adhesion strength (6.7–10.7 MPa) for the polymers cured with the glycoluril crosslinkers, determined by the mechanical tensile and single lap-shear adhesion tests, were higher than those for cured materials produced with PEMB. Thus, the thermal and mechanical properties of the maleimide copolymers were efficiently enhanced by crosslinking using the rigid glycoluril compounds. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 923–931 相似文献
44.
Andreas Meissner Takayuki Kishi Yuka Fujisawa Yuto Murai Hiroyoshi Takamura Isao Kadota 《Tetrahedron letters》2018,59(51):4492-4495
A stereoselective formal total synthesis of enigmazole A, a marine macrolide isolated from Cinachyrella enigmatica, is described. Lewis acid mediated intramolecular allylation of an α-acetoxy ether, prepared from alcohol and carboxylic acid fragments was carried out to construct the methylene THP ring with high stereoselectivity. The late-stage macrolactonization of the corresponding seco-acid provided a known synthetic intermediate of enigmazole A. 相似文献
45.
Frontispiece: Docking Strategy To Construct Thermostable,Single‐Crystalline,Hydrogen‐Bonded Organic Framework with High Surface Area
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46.
A highly efficient and mild method for the synthesis of 1,5-hexadienes, nickel-catalyzed reactions of Boc-protected allyl alcohols with homoallyl alcohols, has been developed. Nickel-mediated retro-allylation allows for the use of homoallyl alcohols as allylmetal equivalents in the synthesis of 1,5-hexadienes. 相似文献
47.
Vinylcyclopropanes bearing one or two electron-withdrawing groups on the cyclopropane ring undergo nickel-catalyzed borylative ring opening with bis(pinacolato)diboron to yield allylic boronates. The reaction proceeded with high E selectivity. 相似文献
48.
Yuto Sumida Yuko Takada Sayuri Hayashi Koji Hirano Hideki Yorimitsu Dr. Koichiro Oshima Prof. Dr. 《化学:亚洲杂志》2008,3(1):119-125
The treatment of an aldehyde with a tertiary homoallylic alcohol at 100–250 °C in the presence of cesium carbonate and a rhodium catalyst leads to allyl transfer from the homoallylic alcohol to the aldehyde. The process includes Rh‐mediated retroallylation to form an allyl rhodium species as the key intermediate. The homoallylic alcohol formed initially through allyl transfer is converted under the reaction conditions into the corresponding saturated ketone when bulky ligands are used. Microwave heating at 250 °C accelerates the reaction significantly. 相似文献
49.
Makoto Yonenaga Yusuke Kaiwa Dr. Kouki Oka Prof. Dr. Kenichi Oyaizu Prof. Dr. Kenji Miyatake 《Angewandte Chemie (International ed. in English)》2023,62(30):e202304366
A proof-of-concept study was conducted on an all-solid-state rechargeable air battery (SSAB) using redox-active 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and its polymer (PDBM) and a proton-conductive polymer (Nafion). DHBQ functioned well in the redox reaction with the solid Nafion ionomer at 0.47 and 0.57 V vs. RHE, similar to that in acid aqueous solution. The resulting air battery exhibited an open circuit voltage of 0.80 V and a discharge capacity of 29.7 mAh gDHBQ−1 at a constant current density (1 mA cm−2). With PDBM, the discharge capacity was much higher, 176.1 mAh gPDBM−1, because of the improved utilization of the redox-active moieties. In the rate characteristics of the SSAB-PDBM, the coulombic efficiency was 84 % at 4 C, which decreased to 66 % at 101 C. In a charge/discharge cycle test, the capacity remaining after 30 cycles was 44 %, which was able to be significantly improved, to 78 %, by tuning the Nafion composition in the negative electrode. 相似文献
50.
Inukai J Miyatake K Ishigami Y Watanabe M Hyakutake T Nishide H Nagumo Y Watanabe M Tanaka A 《Chemical communications (Cambridge, England)》2008,(15):1750-1752
A luminescent porphyrin dye film has been coated onto a transparent separator on the cathode side of a direct methanol fuel cell (DMFC) to visualise clearly oxygen distribution under operating conditions by analysing emission from the dye. 相似文献