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181.
Herein, we report the synthesis of specific silica‐supported Co/Co3O4 core–shell based nanoparticles prepared by template synthesis of cobalt‐pyromellitic acid on silica and subsequent pyrolysis. The optimal catalyst material allows for general and selective hydrogenation of pyridines, quinolines, and other heteroarenes including acridine, phenanthroline, naphthyridine, quinoxaline, imidazo[1,2‐a]pyridine, and indole under comparably mild reaction conditions. In addition, recycling of these Co nanoparticles and their ability for dehydrogenation catalysis are showcased.  相似文献   
182.
Research on Chemical Intermediates - A template consisting of Pd(OAc)2 immobilized on imine-functionalized microporous covalent triazine polymer network (Pd/TATAE) was synthesized and found to be...  相似文献   
183.
Uniform sized single crystal magnetic Fe3O4 hollow spheres (MFHS) have been synthesized through simple solvothermal method using ferric chloride hexahydrate and 1,3-propanediamine. The reaction time and the amount of 1,3-propanediamine play major roles in the formation of magnetic Fe3O4 hollow spheres. The synthesized products are characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometry techniques. The crystalline Fe3O4 materials are composed of well-aligned hollow sphere magnetite nanoparticles and exhibit high saturation magnetization of 57.9?emu/g and a remnant magnetization of 17.6?emu/g at room temperature. MFHS interact strongly with bovine serum albumin (BSA) and brings out considerable conformational changes in BSA as evident from the UV–vis absorption, fluorescence and circular dichroism (CD) spectroscopic studies pertaining to the interaction of synthesized MFHS and BSA. The prepared MFHS effectively inhibit the growth of Pseudomonas aeruginosa and Staphylococcus aureus.  相似文献   
184.
The effect of bulk viscosity on the evolution of the Friedmann models is investigated in the context of open thermodynamic systems, which allows for particle creation. It is seen that, by choosing an appropriate function,(t), for the particle creation, all the models presented exhibit inflationary expansion and a non-singular beginning.  相似文献   
185.
EPR spectra of single crystals of Mn(II)-doped sarcosine cadmium chloride and sarcosine cadmium bromide are studied in Q-band and in X-band at room temperature. Two magnetically inequivalent sites are observed in both the lattices in a distorted octahedral environment. The spin-Hamiltonian parameters are extracted and are found to have a rhombic symmetry. The angular variation of the zero-field transitions is simulated for one of the sites with an asymmetric zero-field tensor D = 480 x 10(-4) cm(-1), E = -115 x 10(-4) cm(-1) and a = 10 x 10(-4) cm(-1) for Mn(II) in sarcosine cadmium chloride and with D = 460 x 10(-4) cm(-1) E = -98 x 10(-4) cm(-1) and a = 10 x 10(-4) cm(-1) for Mn(II) in sarcosine cadmium bromide. The observed large value of zero-field tensor is due to the steric effects of the crystal packing caused by the ligands. Matumura's plot predicts an average covalency of 8.8 and 7.7% for the manganese-ligand bond in SCC and SCB lattices respectively.  相似文献   
186.
A computational study of the interaction half‐sandwich metal fragments (metal = Re/W, electron count = d6), containing linear nitrosyl (NO+), carbon monoxide (CO), trifluorophosphine (PF3), N‐heterocyclic carbene (NHC) ligands with alkanes are conducted using density functional theory employing the hybrid meta‐GGA functional (M06). Electron deficiency on the metal increases with the ligand in the order NHC < CO < PF3 < NO+. Electron‐withdrawing ligands like NO+ lead to more stable alkane complexes than NHC, a strong electron donor. Energy decomposition analysis shows that stabilization is due to orbital interaction involving charge transfer from the alkane to the metal. Reactivity and dynamics of the alkane fragment are facilitated by electron donors on the metal. These results match most of the experimental results known for CO and PF3 complexes. The study suggests activation of alkane in metal complexes to be facile with strong donor ligands like NHC. © 2015 Wiley Periodicals, Inc.  相似文献   
187.
Research on Chemical Intermediates - A series of heterocyclic chalcone derivatives (4a–h) were synthesized and characterized by IR, 1H and 13C NMR as well as MS. All the synthesized compounds...  相似文献   
188.
Glass wool is widely used as an insulating material. Here we report for the first time, the function of glass wool as a mild heterogeneous catalyst under vapor phase conditions — particularly for the rearrangement of styrene oxides including halogen‐substituted styrene oxides to the corresponding phenyl acetaldehydes. Using this methodology, 4‐isobutyl‐α‐methyl styrene oxide is smoothly converted to 4‐isobutyl‐α‐methyl phenyl acetaldehyde which is the precursor of the API “Ibuprofen” — an important pharmaceutical agent.  相似文献   
189.
In this paper attempts have been made to prepare superionic glassy electrolytes in the mixed system 30(Cu(1−x)AgxI)–46.66(Ag2O)–23.33(P2O5), where x=0.05, 0.1, 0.15, 0.2 and 0.25, respectively, using the melt quenching process. The solid samples were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy and silver ionic transport number studies. XRD analysis and FT-IR spectroscopic results have provided details regarding the various phases present in the new system and also indicated the formation of composite materials consisting of glassy and crystalline phases. The transport number measurements have indicated the formation of superionic solids having Ag+ ions as the mobile species in the present system.  相似文献   
190.
Catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are at the heart of water oxidation reactions. Despite continuous efforts, the development of OER/HER electrocatalysts with high activity at low cost remains a big challenge. Herein, a composite material consisting of TC@WO3@g‐C3N4@Ni‐NiO complex matrix as a bifunctional electrocatalyst for the OER and HER is described. Though the catalyst has modest activity for HER, it exhibits high OER activity thereby making it a better nonprecious electrocatalyst for both OER and HER and is further improved by g‐C3N4. The catalytic activity arises from the synergetic effects between WO3, Ni‐NiO, and g‐C3N4. A Ni‐NiO alloy and WO3 nanoparticles decorated on the g‐C3N4 surface supported toray carbon (TC) matrix (TC@WO3@g‐C3N4@Ni‐NiO) by a facile route that show an excellent and durable bifunctional catalytic activity for OER and HER in the alkaline medium are developed. This carbon nitride with binary metal/metal‐oxide matrix supported with TC exhibit an overpotential of 0.385 and 0.535 V versus RHE at a current density of 10 mA cm?2 (Tafel slopes of 0.057 and 0.246 V dec?1 for OER and HER, respectively), in 0.1 m NaOH . The catalyst is tested in water electrolysis for 17 h.  相似文献   
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