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821.
The title compounds, bis(pyridine‐2,6‐dicarboxylato‐N,O,O′)copper(II) monohydrate, [Cu(C7H4NO4)2]·H2O, andbis(pyridine‐2,6‐dicarboxylato‐N,O,O′)zinc(II) trihydrate, [Zn(C7H4NO4)2]·3H2O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl‐N atoms from the two terdentate ligand molecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand molecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand molecules. Both crystal structures are stabilized by O—H?O intermolecular hydrogen bonds between the complex and the water molecules. 相似文献
822.
Nobuo Okabe Michihiro Tsujita 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1418-1419
In the title compound, [Li(C5H3N4O2)(H2O)2]n, the coordinate geometry about the Li+ ion is distorted tetrahedral and the Li+ ion is bonded to N and O atoms of adjacent ligand molecules forming an infinite polymeric chain with Li—O and Li—N bond lengths of 1.901 (5) and 2.043 (6) Å, respectively. Tetrahedral coordination at the Li+ ion is completed by two cis water molecules [Li—O 1.985 (6) and 1.946 (6) Å]. The crystal structure is stabilized both by the polymeric structure and by a hydrogen‐bond network involving N—H?O, O—H?O and O—H?N hydrogen bonds. 相似文献
823.
Shingo Sato Takeshi Watanabe Hironobu Kumagai Nobuo Kitamura Shigeru Matsuba Toshihiro Kumazawa Jun-Ichi Onodera Masanobu Suzuki 《Journal of heterocyclic chemistry》1999,36(5):1189-1193
Condensation of 2-hydroxyacetophenone with benzaldehyde in the presence of 70% perchloric acid in ethyl orthoformate gave the corresponding 4-ethoxyflavylium perchlorate, which was treated with aqueous ammonia or methylamine solution to afford 1,6,7,8-substituted 2-(3′,4′-substituted-phenyl)-4-quinolone in fair to good yield. 相似文献
824.
Mamiko Odoko Kyouta Yamamoto Masahiro Hosen Nobuo Okabe 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):m121-m123
The crystal structures of the title iron(III) and aluminium(III) ethyl maltolate complexes, [Fe(C7H7O3)3] and [Al(C7H7O3)3], respectively, are isomorphous. In each case, the three bidentate ligand molecules are bound to the metal atom, forming a distorted octahedral coordination geometry in a fac configuration. 相似文献
825.
Norio Kashiwa Shin-ichi Kojoh Nobuo Kawahara Shingo Matsuo Hideyuki Kaneko Tomoaki Matsugi 《Macromolecular Symposia》2003,201(1):319-326
This paper describes a new synthetic route for polyolefinic graft block copolymers by adopting coupling reaction between terminally hydroxylated polyolefins and maleic anhydride grafted polyolefins. Terminally hydroxylated polypropylene (PP-OH) was coupled with maleic anhydride modified polyethylene (PE-g-MAH) and such ethylene-propylene random copolymer (EPR-g-MAH) to give polyolefinic graft block copolymers (PE-g-PP and EPR-g-PP, respectively). The formation of PE-g-PP was confirmed by enhancement on molecular weight and it brought about distinctive decrease in size of dispersed domain in its phase separation morphology. Occurrence of coupling reaction to give EPR-g-PP was indicated by extreme decrease in its solubility to n-decane and it led to unique morphology demonstrating lamella microstructure that had never been reported for a comparable polyolefin composite. 相似文献
826.
Nobuo Tanaka Hisashi Nagayama Hiroshi Kobayashi Tohru Ikegami Ken Hosoya Norio Ishizuka Hiroyoshi Minakuchi Kazuki Nakanishi Karin Cabrera Dieter Lubda 《Journal of separation science》2000,23(1):111-116
Two types of monolithic silica columns derivatized to form an ODS phase, one prepared in a fused silica capillary (SR‐FS) and the other prepared in a mold and clad with an engineering plastic (poly‐ether‐ether‐ketone) (SR‐PEEK), were evaluated. The column efficiency and pressure drop were compared with those of a column packed with 5‐μm ODS‐silica particles and of an ODS‐silica monolith prepared in a mold and wrapped with PTFE tubing (SR‐PTFE). SR‐FS gave a lower pressure drop than a column packed with 5‐μm particles by a factor of 20, and a plate height of 20 μm at a linear velocity below 1 mm/s. SR‐PEEK showed higher flow‐resistance than the other monolithic silica columns, but they still showed a minimum plate height of 8–10 μm and a lower pressure drop than popular commercial columns packed with 5‐μm particles. The evaluation of SR‐FS columns in a CEC mode showed much higher efficiency than in a pressure‐driven mode. 相似文献
827.
828.
829.
Kenji Kobayashi Nobuo Deguchi Ohgi Takahashi Kunimasa Tanaka Ernst Horn Osamu Kikuchi Naomichi Furukawa 《Angewandte Chemie (International ed. in English)》1999,38(11):1638-1640
Tellurane oligomers with oxo bridges, namely, the oligotelluroxanes 3 , were prepared from the cationic ditelluroxane 1 and the telluroxide 2 . The reactivity of 3 depends on the cationic character of the terminal telluronium group, and decreases with increasing chain length. Hence the degree of oligomerization can be selectively controlled by means of the ratio of the starting materials 1 and 2 . 相似文献
830.
Preparation and thermal properties of thermoplastic poly(vinyl alcohol) complexes with boronic acids
Hiroshi Nishimura Nobuo Donkai Takeaki Miyamoto 《Journal of polymer science. Part A, Polymer chemistry》1998,36(17):3045-3050
Poly(vinyl alcohol) (PVA) was converted into melt flowable derivatives by complexation with a small amount of n-butyl boronic acid (BBA) and phenyl boronic acid (PBA) in dimethylsulfoxide (DMSO), and their thermal properties were examined from a viewpoint of the melt spinning of the complexes. It was found that (1) the melting temperature of the PVA–boronic acid complexes decreases and their degradation temperature increases with increasing the boronic acid content; (2) no gelation occurs for the PVA complexes with BBA and PBA in DMSO; (3) PBA gives a larger melting-temperature depression for PVA than BBA, but the spinnability of the complexes with BBA is much better than that with PBA; and (4) the melt-molded PVA complex fibers can be easily regenerated into PVA fibers with hot water. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3045–3050, 1998 相似文献