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61.
A. Morozov T. Heindl C. Skrobol J. Wieser R. Krücken A. Ulrich 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(3):383-388
Electron beams with particle energy of ~10 keV were sent through 300 nm thick ceramic (Si3N4 + SiO2) foils and the resulting electron energy distribution functions were recorded using a retarding grid technique. The results
are compared with Monte Carlo simulations performed with two publicly available packages, Geant4 and Casino v2.42. It is demonstrated
that Geant4, unlike Casino, provides electron energy distribution functions very similar to the experimental distributions.
Both simulation packages provide a quite precise average energy of transmitted electrons: we demonstrate that the maximum
uncertainty of the calculated values of the average energy is 6% for Geant4 and 8% for Casino, taking into account all systematic
uncertainties and the discrepancies in the experimental and simulated data. 相似文献
62.
Yasuhi Joh Heimei Yuki Shunsuke Murahashi 《Journal of polymer science. Part A, Polymer chemistry》1970,8(11):3311-3328
The effect of polymerization conditions such as aging time of the catalyst, polymerization temperature, polymerization time, monomer concentration, and catalyst concentration on the polymerization of isobutyl vinyl ether was intensively studied by using the VCI3·LiCl–Al(i-Bu)3 system at an Al(i-Bu)/VCl3·LiCl ratio of 6 at which the cationic polymerization by VCl3·LiCl is sufficiently depressed. About 10 min aging of the catalyst in the presence of monomer yields a fairly stable catalytie system. The optimum polymerization temperature is around 30°C. The conversion increased with increasing monomer concentration, whereas the stereospecificity of polymerization decreased. Unexpectedly, the conversion decreased as total catalyst concentration increased. This phenomenon is explained by considering the deactivation of catalytic sites by the excess of Al(i-Bu)3. A reasonable mechanism from kinetic considerations is that two molecules of Al(i-Bu)3 deactivate the catalytic site in an equilibrium reaction. This deactivation is understandable by considering that the coordination of two molecules of Al(i-Bu)3 will occupy all the coordination positions of vanadium, so that there is no room for coordination of monomer coming to the catalytic site. 相似文献
63.
Dr. Fabian Dielmann Dr. Eugenia V. Peresypkina Barbara Krämer Florian Hastreiter Dr. Brian P. Johnson Dr. Manfred Zabel Dr. Claudia Heindl Prof. Dr. Manfred Scheer 《Angewandte Chemie (International ed. in English)》2016,55(47):14833-14837
The cyclo‐P4 complexes [CpRTa(CO)2(η4‐P4)] (CpR: Cp′′=1,3‐C5H3tBu2, Cp′′′=1,2,4‐C5H2tBu3) turned out to be predestined for the formation of hollow spherical supramolecules with non‐classical fullerene‐like topology. The resulting assemblies constructed with CuX (X=Cl, Br) showed a highly symmetric 32‐vertex core of solely four‐ and six‐membered rings. In some supramolecules, the inner cavity was occupied by an additional CuX unit. On the other hand, using CuI, two different supramolecules with either peanut‐ or pear‐like shapes and outer diameters in the range of 2–2.5 nm were isolated. Furthermore, the spherical supramolecules containing Cp′′′ ligands at tantalum are soluble in CH2Cl2. NMR spectroscopic investigations in solution revealed the formation of isomeric supramolecules owing to the steric hindrance caused by the third tBu group on the Cp′′′ ligand. In addition, a 2D coordination polymer was obtained and structurally characterized. 相似文献
64.
Rudolf Ochs W. Fresenius P. Saccardi Weber J. M. Kolthoff H. Hamer H. Röttger E. Schowalter E. Spaeth A. Gompf J. Gerum G. Metge A. Röhrig L. Fresenius G. de Astis A. Bornträger H. Astruc Radet M. Martini A. Nourrisson L. Roos A. Kling A. Lassieur M. François Ch. Lormand J. Dubaquié P. Chauvet J. L. Chelle G. Filaudeau Bonis H. Boßelmannn F. Mach M. Fischler C. von der Heide Joh Pinnow D. Fonzes-Diakon L. Semichon K. Kroemer R. Meissner A. Widmer O. Kalberer L. Minder Th. v. Fellenberg G. Chancel P. Balavoine X. Roques C. Lagneau von der Heide 《Analytical and bioanalytical chemistry》1926,68(12):469-480
65.
Dr. Claudia Heindl Dr. Eugenia V. Peresypkina David Lüdeker Dr. Gunther Brunklaus Dr. Alexander V. Virovets Prof. Dr. Manfred Scheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(8):2599-2604
The all‐phosphorus analogue of benzene, stabilized as middle deck in triple‐decker complexes, is a promising building block for the formation of graphene‐like sheet structures. The reaction of [(CpMo)2(μ,η6:η6‐P6)] ( 1 ) with CuX (X=Br, I) leads to self‐assembly into unprecedented 2D networks of [{(CpMo)2P6}(CuBr)4]n ( 2 ) and [{(CpMo)2P6}(CuI)2]n ( 3 ). X‐ray structural analyses show a unique deformation of the previously planar cyclo‐P6 ligand. This includes bending of one P atom in an envelope conformation as well as a bisallylic distortion. Despite this, 2 and 3 form planar layers. Both polymers were furthermore analyzed by 31P{1H} magic angle spinning (MAS) NMR spectroscopy, revealing signals corresponding to six non‐equivalent phosphorus sites. A peak assignment is achieved by 2D correlation spectra as well as by DFT chemical shift computations. 相似文献
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69.
Joh Pinnow 《Fresenius' Journal of Analytical Chemistry》1902,41(8):485-488
Ohne Zusammenfassung 相似文献
70.
Han OH Han KS Shin CW Lee J Kim SS Um MS Joh HI Kim SK Ha HY 《Angewandte Chemie (International ed. in English)》2012,51(16):3842-3845
The chemical conversion of methanol in direct methanol fuel cells was followed in situ by NMR spectroscopy. Comparing data of the methanol oxidation on Pt and PtRu anode catalysts allowed the role of Ru in both Faradaic and non-Faradaic reactions to be investigated. The spatial distributions of chemicals could also be determined. (Picture: T1-T4=inlet and outlet tubes.). 相似文献