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381.
Adelina-Antonia Andelescu Dr. Benoît Heinrich Maria Angela Spirache Emilie Voirin Prof. Massimo La Deda Giuseppe Di Maio Dr. Elisabeta I. Szerb Dr. Bertrand Donnio Dr. Otilia Costisor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(21):4850-4860
Blue–green luminescent terpyridine-containing PtII and ZnII complexes are reported. Equipped with lipophilic gallate units, which act as monodentate ancillary coordinating ligands and/or as anions, they display low-temperature mesomorphic properties (lamello-columnar and hexagonal mesophases for PtII and ZnII complexes, respectively). The mesomorphic properties were investigated by polarised optical microscopy, differential scanning calorimetry, thermogravimetric analysis and X-ray scattering of bulk materials and oriented thin films. The model of self-assembly into the lamello-columnar phase of the PtII complex has been described in detail. The optical properties of the complexes were investigated in the liquid and condensed liquid crystalline states, highlighting the delicate balance between the role of the metal in determining the type of excited state responsible for the emission, and the role of the ancillary ligand in driving intermolecular interactions for proper mesophase formation. 相似文献
382.
Dr. Keihann Yavari Dr. Wylliam Delaunay Dr. Nicolas De Rycke Thibault Reynaldo Dr. Paul Aillard Dr. Monika Srebro-Hooper Victoria Y. Chang Dr. Gilles Muller Dr. Denis Tondelier Bernard Geffroy Dr. Arnaud Voituriez Dr. Angela Marinetti Prof. Muriel Hissler Dr. Jeanne Crassous 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(20):5303-5310
Herein, the experimental physicochemical and chiroptical properties of a series of phosphahelicenes are reported, focusing on their UV/Vis absorption, luminescence, electronic circular dichroism, optical rotations, and circularly polarized luminescence. Furthermore, detailed analysis of absorption and ECD spectra performed with the help of quantum-chemical calculations allowed us to highlight general features of these helicenic phosphines. Finally, due to well-suited electrochemical properties and thermal stability, the systems were successfully used as emitters in organic light-emitting diodes. 相似文献
383.
Two families of aldols, obtained from the condensation of aromatic aldehydes with cyclohexanone or acetone (ten examples in each group), were analyzed by high‐performance liquid chromatography in normal phase elution mode on three polysaccharide‐based chiral stationary phases of the Lux series, namely, Lux Cellulose‐2, Lux Cellulose‐4 and Lux Amylose‐2, which share the common feature of chlorinated substituents in the chiral selectors. Following simple optimization steps, the enantioseparation of all aldols derived from cyclohexanone was achieved and the highest values of separation factor (α, 1.32 < α < 2.20) and resolution (Rs, 4.5 < Rs <17.2) were observed on Lux Cellulose‐2, with the only exception of the 4‐nitro‐substituted derivative that was better resolved on Lux Cellulose‐4. On the contrary, Lux Amylose‐2 was the best choice for aldols derived from acetone and only specific analytes in this group were resolved on the cellulose‐based supports. A variable‐temperature study of selected compounds allowed us to determine thermodynamic parameters of the enantioseparation process, which was enthalpy‐controlled in all the cases except one. 相似文献
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385.
ChristopherW. Cunningham Kellie Hom Chayan Acharya Angela Wilks AlexanderD. MacKerell Andrew Coop 《Helvetica chimica acta》2010,93(2):220-226
The Diels–Alder reaction was applied to 4,5‐epoxymorphinan opioids to generate a novel aromatic cycloadduct at C(7) C(8): Thermolytic cleavage of sultine 8 produced the reactive diene o‐quinodimethane 7 which condensed favorably with codeine ( 11 ), but not with codeinone ( 9 ) or 14‐hydroxycodeinone ( 10 ), producing the desired tetrahydronaphtho adduct 12 with (7R,8R) geometry (Scheme). The configuration of the cycloadduct was determined by 1D‐ and 2D‐NMR experiments. The unanticipated reactivity of these codeine derivatives was investigated by quantum‐mechanical calculations, and it was determined that steric effects of the 6‐keto and 14‐hydroxy group likely precluded condensation by raising the molecular energy of their respective transition states. 相似文献
386.
Patrick Fadden Kenneth H. Huang James M. Veal Paul M. Steed Amy F. Barabasz Briana Foley Mei Hu Jeffrey M. Partridge John Rice Anisa Scott Laura G. Dubois Tiffany A. Freed Melanie A. Rehder Silinski Thomas E. Barta Philip F. Hughes Andy Ommen Wei Ma Emilie D. Smith Angela Woodward Spangenberg Jeron Eaves Steven E. Hall 《Chemistry & biology》2010,17(7):686-694
387.
Sparfosic acid can easily be prepared in two steps and in excellent yield from condensation of the commercially available starting materials L-aspartic acid di-tert-butyl ester hydrochloride and diethylphosphonoacetic acid, followed by a quadruple deprotection of acidic functions under mild conditions using bromotrimethylsilane. 相似文献
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390.
Ana C. Stephens Eric J. Knuth Maria L. Blanton Isil Isler Angela Murphy Gardiner Tim Marum 《The Journal of Mathematical Behavior》2013
This paper reports results from a written assessment given to 290 third-, fourth-, and fifth-grade students prior to any instructional intervention. We share and discuss students’ responses to items addressing their understanding of equation structure and the meaning of the equal sign. We found that many students held an operational conception of the equal sign and had difficulty recognizing underlying structure in arithmetic equations. Some students, however, were able to recognize underlying structure on particular tasks. Our findings can inform early algebra efforts by highlighting the prevalence of the operational view and by identifying tasks that have the potential to help students begin to think about equations in a structural way at the very beginning of their early algebra experiences. 相似文献