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141.
A novel heterometallic 3d-4f metal-azido complex of mixed ligands, showing unprecedented structure type and interesting magnetic properties, has been hydrothermally synthesized and characterized. 相似文献
142.
A new end-on azide-bridged dimeric Mn(III) complex has been synthesized by using the tridentate N-isonicotinamidosalicylaidimine ligand. Magnetic studies show that the complex has a high-spin ground state of S = 4 and is ac out-of-phase frequency-dependent. 相似文献
143.
Sarkar S Datta A Mondal A Chopra D Ribas J Rajak KK Sairam S M S Pati SK 《The journal of physical chemistry. B》2006,110(1):12-15
Synthesis, structural characteristics, magnetic studies and DFT calculations in Ni(II) dinuclear complexes containing two bridging N3- and an O-H...O linkage reveal the existence of ferromagnetic interactions between Ni(II) centers via N3- ligands and antiferromagnetic interactions through the H-bonded moiety. The overall magnetic behavior of the system depends on the delicate balance between these two competing interactions. 相似文献
144.
145.
Shuang Hou Libo Zhao Qinglin Shen Juehua Yu Charles Ng Xiangju Kong Dongxia Wu Min Song Xiaohong Shi Xiaochun Xu Wei‐Han OuYang Rongxian He Xing‐Zhong Zhao Tom Lee F. Charles Brunicardi Mitch Andr Garcia Antoni Ribas Roger S. Lo Hsian‐Rong Tseng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2013,125(12):3463-3467
146.
Dr. Jordi Ribas‐Arino Dr. Maria Angels Carvajal Dr. Alain Chaumont Dr. Marco Masia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(49):15868-15874
A multiscale computational study was performed with the aim of tracing the source of stereoselectivity and disclosing the role of water in the stereoselective step of propionaldehyde aldol self‐condensation catalyzed by proline amide in water, a reaction that serves as a model for aqueous organocatalytic aldol condensations. Solvent mixing and hydration behavior were assessed by classical molecular dynamics simulations, which show that the reaction between propanal and the corresponding enamine takes place in a fully hydrated environment. First‐principles molecular dynamics simulations were used to study the free‐energy profile of four possible reaction paths, each of which yields a different stereoisomer, and high‐level static first‐principles calculations were employed to characterize the transition states for microsolvated species. The first solvation shell of the oxygen atom of the electrophilic aldehyde at the transition states contains two water molecules, each of which donates one hydrogen bond to the nascent alkoxide and thereby largely stabilizes its excess electron density. The stereoselectivity originates in an extra hydrogen bond donated by the amido group of proline amide in two reaction paths. 相似文献
147.
Du M Zhang ZH Li CP Ribas-Ariño J Aliaga-Alcalde N Ribas J 《Inorganic chemistry》2011,50(15):6850-6852
The reaction of copper(II) nitrate, oxamide, and an angular bridging ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) under hydrothermal conditions affords a 3D pillared-layer coordination framework {[Cu(2)(4-bpo)(ox)(2)](H(2)O)(4)}(n) (1) (ox = oxalate), featuring the unique zeolite-type NiP(2) network and interesting properties. 相似文献
148.
149.
Figuerola A Tangoulis V Ribas J Hartl H Brüdgam I Maestro M Diaz C 《Inorganic chemistry》2007,46(26):11017-11024
The synthesis, crystal structure, and magnetic properties of two trinuclear oxo-centered carboxylate complexes are reported and discussed: [Cr3(mu3-O)(mu2-PhCOO)6(H2O)3]NO3.4H2O.2CH3OH (1) and [Cr3(mu3-O)(mu2-PhCOO)2(mu2-OCH2CH3)2(bpy)2(NCS)3] (2). For both complexes the crystal system is monoclinic, with space group C2/c for 1 and P1/n for 2. The structure of complex 1 consists of discrete trinuclear cations, associated NO3- anions, and lattice methanol and water molecules. The structure of complex 2 is built only by neutral discrete trinuclear entities. The most important feature of 2 is the unusual skeleton of the [Cr3O] core due to the lack of peripheral bridging ligands along one side of the triangular core, which is unique among the structurally characterized (mu3-oxo)trichromium(III) complexes. Magnetic measurements were performed in the 2-300 K temperature range. For complex 1, in the high-temperature region (T > 8 K), experimental data could be satisfactorily reproduced by using an isotropic exchange model, H = -2J12S1S2 - 2J13S1S3 - 2J23S2S3 (J12 = J13 = J23) with Jij = -10.1 cm(-1), g = 1.97, and TIP = 550 x 10(-6) emu mol(-1). The antisymmetric exchange interaction plays an important role in the magnetic behavior of the system, so in order to fit the experimental magnetic data at low temperature, a new magnetic model was used where this kind of interaction was also considered. The resulting fitting parameters are the following: Gzz = 0.25 cm(-1), delta = 2.5 cm(-1), and TIP = 550 x 10(-6) emu mol(-1). For complex 2, the experimental data could be satisfactorily reproduced by using an isotropic exchange model, H = -2J1(S1S2 + S1S3) - 2J2(S2S3) with J1 = -7.44 cm(-1), J2 = -51.98 cm(-1), and g = 1.99. The magnetization data allows us to deduce the ground term of S = 1/2, characteristic of equilateral triangular chromium(III) for complex 1 and S = 3/2 for complex 2, which is confirmed by EPR measurements. 相似文献
150.
A novel one-dimensional manganese(II) azido complex, [Mn2(N3)4(phen)2]n (1), in which the azido bridging ligands take on an unusual new type of combination with the metal center as the sign of [-EO-EO-EO-EE-]n, has been hydrothermally synthesized, and its magnetic properties have been studied. 相似文献