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981.
Dr. Moulali Vaddamanu Dr. Arruri Sathyanarayana Yamane Masaya Shohei Sugiyama Ozaki Kazuhisa Dr. Kavitha Velappan Muneshwar Nandeshwar Dr. Kyohei Hisano Osamu Tsutsumi Prof. Dr. Ganesan Prabusankar 《化学:亚洲杂志》2021,16(5):521-529
The synthesis and the luminescence features of three gold(I)-N-heterocyclic carbene (NHC) complexes are presented to study how the n-alkyl group can influence the luminescence properties in the crystalline state. The mononuclear gold(I)-NHC complexes, [( L1 )Au(Cl)] ( 1 ), [( L2 )Au(Cl)] ( 2 ), and [( L3 )Au(Cl)] ( 3 ) were isolated from the reactions between [(tht)AuCl] and corresponding NHC ligand precursors, [N-(9-acridinyl)-N’-(n-butyl)-imidazolium chloride, ( L1 .HCl)], [N-(9-acridinyl)-N’-(n-pentyl)-imidazolium chloride, ( L2 .HCl)] and [N-(9-acridinyl)-N’-(n-hexyl)-imidazolium chloride, ( L3 .HCl)]. Their single-crystal X-ray analysis reveals the influence of the n-alkyl groups on solid-state packing. A comparison of the luminescence features of 1 – 3 with n-alkyl substituents is explored. The molecules 1 – 3 depicted blue emission in the solution state, while the yellow emission (for 1 ), greenish-yellow emission (for 2 ), and blue emission (for 3 ) in the crystalline phase. This paradigm emission shift arises from n-butyl to n-pentyl and n-hexyl in the crystalline state due to the carbon-carbon rotation of the n-alkyl group, which tends to promote unusual solid packing. Hence n-alkyl group adds a novel emission property in the crystalline state. Density Functional Theory and Time-Dependent Density Functional Theory calculations were carried out for monomeric complex, N-(9-acridinyl)-N’-(n-heptyl)imidazole-2-ylidene gold(I) chloride and dimeric complex, N-(9-acridinyl)-N’-(n-heptyl)imidazole-2-ylidene gold(I) chloride to understand the structural and electronic properties. 相似文献
982.
Junqiu Li Dr. Shuqi Wu Dr. Shengqun Su Dr. Shinji Kanegawa Prof. Osamu Sato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(15):3259-3263
Some cyanide-bridged complexes are known for exhibiting slow magnetic relaxation behavior in a light-induced metastable state. Herein, an unexpected reverse effect is observed for the first time in the S= {FeIILS-CoIIILS-FeIIILS} (HS=high spin, LS=low spin) ground state of a novel V-shaped trinuclear cyanide-bridged {Fe2Co} complex. In this complex, light-switchable iron-cobalt charge transfer with repeatable off/on switching of slow magnetic relaxation is discovered upon alternating laser irradiation at 785 and 560 nm. An important characteristic of the present compound is that the S= ground state exhibits slow magnetic relaxation before irradiation, whereas this is accelerated after irradiation. This is different from the typical behavior, where the light-induced metastable state exhibits slow magnetic relaxation. 相似文献
983.
984.
985.
986.
We propose a new method for authenticating valuable paper sheets such as gift coupons, tickets, and cheques with the use of
optical coherence tomography (OCT). This method is based on the detection and evaluation of cross-sectional structural characteristics
of valuable paper sheets provided with security features. Commonly used as a security feature is a security thread, which
is embedded in such paper sheets. In this paper, the nondestructive detection of the embedded security thread is demonstrated
using spectral-domain OCT. The results showed that the security thread was clearly visualized in the OCT image despite the
highly scattering nature of papers. 相似文献
987.
Satoru Urakawa Naokiigawa Norimasa Umesaki Kazuo Igarashi Osamu Shimomura Hideo Ohno 《高压研究》2013,33(4-6):375-382
Abstract Energy-dispersive X-ray diffraction experiments of molten KCl under high pressure have been carried out by using synchrotron radiation. The diffraction profiles of molten KCl were acquired just above the melting temperature of KCl up to 4 GPa. The reduced structure factor S(Q)'s for molten KCl do not show any change in their primary features, except for a gradual increase in the first peak intensity with increasing pressure. This implies that molten KCl does not show a first-order phase transition, such as the B1-B2 transition, found in solid KCl, but that the local structure in molten KCl must be changed by compression. According to a molecular-dynamics simulation, this change of S(Q) can be explained by a continuous increase in the coordination number of the nearest-neighbor ions in molten KCl with pressure. 相似文献
988.
989.
Masaki Moritsugu Tomomi Shirota Shoichi Kubo Tomonari Ogata Osamu Sato Seiji Kurihara 《Journal of Polymer Science.Polymer Physics》2009,47(20):1981-1990
Photo‐chemically tunable photonic band gap materials are prepared by infiltration of liquid crystal polymers having azobenzene groups into voids of SiO2 inverse opal films. Linearly polarized (LP) light irradiation results in transformation from a random to an anisotropic molecular orientation of azobenzene side chains in the voids of the SiO2 inverse opal film, leading to the reversible and stable shift of the reflection peak to longer wavelength more than 15 nm. To improve switching properties, we use copolymers of azobenzene monomer and tolane monomer, which have higher birefringence, as infiltration materials into the voids. The azobenzene‐tolane copolymers are found to show higher birefringence than azobenzene homopolymers by the LP light irradiation at higher temperature. Consequently, the reflection band of the SiO2 inverse opal film infiltrated with the azobenzene‐tolane copolymer can be shifted to longer wavelength region more than 55 nm by the irradiation of LP light. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1981–1990, 2009 相似文献
990.
Noriaki Moriyama Yoshihiro Matsumura Masami Kuriyama Osamu Onomura 《Tetrahedron: Asymmetry》2009,20(23):2677-2687
A new method using electrochemical oxidation and/or OsO4 oxidation has been used for the stereoselective synthesis of 2,3,6-trihydroxylated (5S)-piperidine derivatives. The electrochemical method was successively used for the conversion of N-protected piperidines to N-protected 1-methoxypiperidines and for the conversion of 2,3-didehydro-1-methoxypiperidine derivatives to 2,3-trans-1,2,3-triacetoxypiperidine derivatives. These triacetates were easily transformed into (2S,3S)-6-triacetoxy-(5S)-methylpiperidine and (2R,3R)-6-triacetoxy-(5S)-methylpiperidine. In addition, the 2,3-cis-dihydroxylation of 2,3-didehydro-1-methoxypiperidine derivatives with OsO4 afforded (2R,3S)-6-triacetoxy-(5S)-methylpiperidine and (2S,3R)-6-triacetoxy-(5S)-methylpiperidine. 相似文献