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61.
Diemer V Berthelot A Bayardon J Jugé S Leroux FR Colobert F 《The Journal of organic chemistry》2012,77(14):6117-6127
A new aryne-mediated tandem cross-coupling/P-cyclization sequence starting from tertiary phosphine-boranes and 1,2-dibromobenzenes is reported. P-chirogenic dibenzophospholes become accessible in a regio-, chemo-, and diastereoselective way. 相似文献
62.
63.
Agnès Rivaton Sylvain Chambon Jean-Luc Gardette Stéphane Guillerez 《Polymer Degradation and Stability》2010,95(3):278-2251
Polymer-based organic solar cells are known to offer a poor stability in real use conditions, and the photodegradation of the active organic layer plays an important role in the reduced lifetime of the devices. This paper focuses on the photodegradation of two conjugated polymers used in organic solar cells, namely poly(2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene (MDMO-PPV) and poly(3-hexyylthiophene) (P3HT), and their blends with [60]PCBM (methano-fullerene[6,6]-phenyl C61-butyric acid methyl ester), a fullerene derivative. MDMO-PPV and P3HT thin films were submitted to photoageing (λ > 300 nm) in the presence and in the absence of oxygen. The mechanisms by which these polymers degrade were elucidated. P3HT, pristine and blended with PCBM, was shown to be much more stable under illumination than MDMO-PPV. The results showed that, if deposited on an inert substrate and well protected from oxygen with a convenient encapsulation, P3HT:PCBM based active layer should be intrinsically stable for several years in use conditions. 相似文献
64.
Tailoring the Structure of Two‐Dimensional Self‐Assembled Nanoarchitectures Based on NiII–Salen Building Blocks 下载免费PDF全文
Dr. Marta Viciano‐Chumillas Dongzhe Li Dr. Alexander Smogunov Dr. Sylvain Latil Dr. Yannick J. Dappe Dr. Cyrille Barreteau Prof. Talal Mallah Dr. Fabien Silly 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13566-13575
The synthesis of a series of NiII–salen‐based complexes with the general formula of [Ni(H2L)] (H4L=R2‐N,N′‐bis[R1‐5‐(4′‐benzoic acid)salicylidene]; H4L1: R2=2,3‐diamino‐2,3‐dimethylbutane and R1=H; H4L2: R2=1,2‐diaminoethane and R1=tert‐butyl and H4L3: R2=1,2‐diaminobenzene and R1=tert‐butyl) is presented. Their electronic structure and self‐assembly was studied. The organic ligands of the salen complexes are functionalized with peripheral carboxylic groups for driving molecular self‐assembly through hydrogen bonding. In addition, other substituents, that is, tert‐butyl and diamine bridges (2,3‐diamino‐2,3‐dimethylbutane, 1,2‐diaminobenzene or 1,2‐diaminoethane), were used to tune the two‐dimensional (2D) packing of these building blocks. Density functional theory (DFT) calculations reveal that the spatial distribution of the LUMOs is affected by these substituents, in contrast with the HOMOs, which remain unchanged. Scanning tunneling microscopy (STM) shows that the three complexes self‐assemble into three different 2D nanoarchitectures at the solid–liquid interface on graphite. Two structures are porous and one is close‐packed. These structures are stabilized by hydrogen bonds in one dimension, while the 2D interaction is governed by van der Waals forces and is tuned by the nature of the substituents, as confirmed by theoretical calculations. As expected, the total dipolar moment is minimized 相似文献
65.
Martin-del-Campo Jennifer Coulombe Sylvain Kopyscinski Jan 《Plasma Chemistry and Plasma Processing》2020,40(4):857-881
Plasma Chemistry and Plasma Processing - The environmental impact of greenhouse gases such as carbon dioxide and methane can be reduced if they are used as feedstock to synthesize chemical building... 相似文献
66.
Chen JC Juanes-Marcos JC Woittequand S Somers MF Díaz C Olsen RA Kroes GJ 《The Journal of chemical physics》2011,134(11):114708
Based on a slab model of H(2) dissociation on a c(2 × 2) structure with Ti atoms in the first and third layers of Al(100), a six-dimensional (6D) potential energy surface (PES) has been built. In this PES, a molecular adsorption well with a depth of 0.45 eV is present in front of a barrier of height 0.13 eV. Using this PES, H(2) dissociation probabilities are calculated by the classical trajectory (CT), the quasiclassical trajectory (QCT), and the time-dependent wave-packet (TDWP) method. The QCT study shows that trajectories can be trapped by the molecular adsorption well. Higher incident energy can lead to direct H(2) dissociation. Vibrational pre-excitation is the most efficient way to promote direct dissociation without trapping. We find that both rotational and vibrational excitation have efficacies close to 1.0 in the entire range of incident energies investigated, which supports the randomization in the initial conditions making the reaction rate solely dependent on the total (internal and translational) energy. The H(2) dissociation probabilities from quantum dynamics are in reasonable agreement with the QCT results in the energy range 50-200 meV, except for some fluctuations. However, the TDWP results considerably exceed the QCT results in the energy range 200-850 meV. The CT reaction probabilities are too low compared with the quantum dynamical results. 相似文献
67.
Wilson AA Garcia A Houle S Sadovski O Vasdev N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(1):259-264
Carbon-11 labeled isocyanates are efficiently prepared by dehydration of [(11) C]carbamate salts, which in turn are easily formed from cyclotron-produced [(11) C]CO(2) and amines in the presence of a CO(2) fixation agent. The [(11) C]isocyanates are useful radiosynthons for the synthesis of a variety of [carbonyl-(11) C]-labeled asymmetrical ureas and carbamate esters. The method is well suited to incorporate any isotope of carbon, and is especially useful for positron emission tomography (PET) radiotracers for in vivo imaging. This is demonstrated by using the method to make [carbonyl-(11) C]-6-hydroxy-[1,1'-biphenyl]-3-yl cyclohexylcarbamate which is a novel radiotracer for PET imaging of fatty acid amide hydrolase. 相似文献
68.
Besson C Mirebeau JH Renaudineau S Roland S Blanchard S Vezin H Courillon C Proust A 《Inorganic chemistry》2011,50(6):2501-2506
The scope of N-atom transfer from the electrophilic ruthenium(VI) nitrido containing polyoxometalate [PW(11)O(39)Ru(VI)N](4-) has been extended to the N-heterocyclic carbene {CH(2)(Mes)N}(2)C and the coupling product {CH(2)(Mes)N}(2)CNH(2)(+) characterized by (1)H NMR and high-resolution mass spectrometry. Because guanidines display many fields of applications ranging from biology to supramolecular chemistry, this could afford an original route to the synthesis of cyclic guanidines. This also enlarges the potential of nitrido complexes in the synthesis of heterocycles, mainly illustrated in the literature through the formation of aziridines through N-atom transfer to alkenes. In the course of the reaction, the ruthenium(III)-containing polyoxometallic intermediate [PW(11)O(39)Ru(III){NC{N(Mes)CH(2)}(2)}](5-) has been thoroughly characterized by continuous-wave and pulsed electron paramagnetic resonance, which nicely confirms the presence of the organic moiety on the polyoxometallic framework, Ru K-edge X-ray absorption near-edge structure, and electrochemistry. 相似文献
69.
The development of a user-friendly reusable laboratory equipment for the delivery of sensitive reagents and catalysts is described. The tightness of these Teflon Magnetic Stirring Capsules (TMSC) is ensured by the magnetic force and release of the reagent inside the solution is triggered by adjusting the stirring rate so that the centrifuge force exceeds the magnetic force. They can be loaded with several chemicals at the same time and do operate across a broad range of temperatures. The inertness of Teflon facilitates reaction purification. 相似文献
70.
Lahboub Bouyazza Jean-Charles Lancelot Sylvain Rault Max Robba 《Journal of heterocyclic chemistry》1991,28(1):77-80
A-Acetoxypyrrolo[1,2a]quinolines 26-30 were synthesized by cyclization of 2-(1-pyrroly)phenylacetic acids 21-25 with acetic anhydride. The structures of the new compounds were determined by 1H-nmr spectroscopy. 相似文献