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61.
Masato Hashimoto Takafumi Kitazawa Tai Hasegawa Toschitake Iwamoto 《Journal of inclusion phenomena and macrocyclic chemistry》1991,11(2):153-158
The Hofmann-danon-typeo-xylene clathrate Cd[NH2(CH2)9NH2]Ni(CN)4·0.5(CH3)2C6H4, crystallizes in the triclinic space groupP witha = 15.118(3),b = 14.048(4),c = 7.325(1) Å, = 91.50(2), = 131.66(3), and = 107.50(2)°,V = 1051(1) Å3 andZ = 2. The structure, refined toR = 0.047 using 2851 reflections, reveals a three-dimensional host framework built of the layers of a two-dimensionalcatena-[cadmium tetra--cyanonickelate(Il)] network and of the ambidentate 1,9-diaminononane (danon) bridging the Cd atoms in adjacent networks. The guesto-xylene molecule is accommodated in the cavity formed in the interlayer space similar to that in the Hofmann-daotn-type. The skeleton of the danon in the Cd-NC9N-Cd linkage takes a (gauche)2(trans)8 conformation twisted at the (gauche)2 part in contrast with the all-trans conformation of 1,8-diaminononane in the Hofmann-daotn-type clathrate. The twisted (gauche)2 part of the danon skeleton occupies the interlayer space to such an extent that void space available for the guest o-xylene molecule decreases to half that in the Hofmann-daotn-type clathrate Cd[NH2(CH2)8NH2]Ni(CN)4·G.The Crystal structures of ,-Diaminoalkanecadmium(II)Tetracyanonickelate(II) - Aromatic Molecule Inclusion Compounds. VI. 相似文献
62.
The photochemical reactions of 2‐substituted N‐(2‐halogenoalkanoyl) derivatives 1 of anilines and 5 of cyclic amines are described. Under irradiation, 2‐bromo‐2‐methylpropananilides 1a – e undergo exclusively dehydrobromination to give N‐aryl‐2‐methylprop‐2‐enamides (=methacrylanilides) 3a – e (Scheme 1 and Table 1). On irradiation of N‐alkyl‐ and N‐phenyl‐substituted 2‐bromo‐2‐methylpropananilides 1f – m , cyclization products, i.e. 1,3‐dihydro‐2H‐indol‐2‐ones (=oxindoles) 2f – m and 3,4‐dihydroquinolin‐2(1H)‐ones (=dihydrocarbostyrils) 4f – m , are obtained, besides 3f – m . On the other hand, irradiation of N‐methyl‐substituted 2‐chloro‐2‐phenylacetanilides 1o – q and 2‐chloroacetanilide 1r gives oxindoles 2o – r as the sole product, but in low yields (Scheme 3 and Table 2). The photocyclization of the corresponding N‐phenyl derivatives 1s – v to oxindoles 2s – v proceeds smoothly. A plausible mechanism for the formation of the photoproducts is proposed (Scheme 4). Irradiation of N‐(2‐halogenoalkanoyl) derivatives of cyclic amines 5a – c yields the cyclization products, i.e. five‐membered lactams 6a , b , and/or dehydrohalogenation products 7a , c and their cyclization products 8a , c , depending on the ring size of the amines (Scheme 5 and Table 3). 相似文献
63.
Lixin Xiao Hidekazu Shimotani Masaki Ozawa Jing Li Nita Dragoe Kazuhiko Saigo Koichi Kitazawa 《Journal of polymer science. Part A, Polymer chemistry》1999,37(18):3632-3637
A novel [60]fullerene pearl-necklace polymer, poly(4,4′-carbonylbisphenylene trans-2-[60]fullerenobisacetamide), was synthesized by a direct polycondensation of trans-2-[60]fullerenobisacetic acid with 4,4′-diaminobenzophenone in the presence of large excesses of triphenyl phosphite and pyridine. In the present polymer, [60]fullerene pearls and diamine linkers were attached to each other by methano-carbonyl connectors. The molecular weight Mw of the polymer was determined to be 4.5 × 104 on the basis of the TOF-MS, and a GPC analysis of the polymer using polystyrene standards showed a weight-average molecular weight of 5.3 × 104. The UV-vis spectrum of the resultant polymer in N,N-dimethylacetamide (DMAc) exhibited a broad absorption (λmax 310 nm, ε 2.1 × 104 L · mol−1 · cm−1), tailing to longer wavelengths, and a fluorenscence peak centered at 550 nm was observed in DMAc. There was observed a large downfield-shift of the cyclopropane methyne proton in the 1H-NMR spectra from 4.57 ppm of the ethyl ester to 5.78 ppm of the polyamide. These observations indicate that the present polyamide is a high-molecular-weight [60]fullerene pearl-necklace polymer and that the cyclopropane rings are efficient to make the [60]fullerene cages and the diamine components conjugatable. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3632–3637, 1999 相似文献
64.
65.
K. Hashi T. Shimizu A. Goto H. Kitazawa G. Kido T. Suzuki 《Applied Physics A: Materials Science & Processing》2000,70(3):359-360
An NMR quantum computer based on an integrated device with CeP has been proposed by Yamaguchi and Yamamoto [Appl. Phys. A 68 1 (1999)]. We point out two problems in their scheme. We also investigate experimentally the 31P NMR spectra for our CeP. From the line width, we find that improvement of the sample quality is necessary to satisfy the experimental conditions for a quantum computer. 相似文献
66.
Hall coefficient, resistivity and superconducting upper critical field Hn2 were measured on single-crystalline BaPb1?xBixO3 of compositions x = 0.20, 0.12 and 0, of which the normal-state properties differ significantly from those of polycrystals. The slope dHn2/dT at Tc was estimated from the normal-state parameters and was found to agree well with the observed value, suggesting that this material is a bulk BCS superconductor. 相似文献
67.
Takeda Masuo Wang Junhu Nishimura Tatsuru Suzuki Katsuya Kitazawa Takafumi Takahashi Masashi 《Hyperfine Interactions》2004,156(1-4):359-364
Hyperfine Interactions - We have examined the 155Gd Mössbauer spectra at 12 K for 25 complexes having different coordination numbers and different ratios of coordinating oxygen to nitrogen... 相似文献
68.
We investigate the correlators of TrAμAν in matrix models on homogeneous spaces: S2 and S2×S2. Their expectation value is a good order parameter to measure the geometry of the space on which non-commutative gauge theory is realized. They also serve as the Wilson lines which carry the minimum momentum. We develop an efficient procedure to calculate them through 1PI diagrams. We determine the large N scaling behavior of the correlators. The order parameter shows that fuzzy S2×S2 acquires a 4-dimensional fractal structure in contrast to fuzzy S2. We also find that the two point functions exhibit logarithmic scaling violations. 相似文献
69.
A. Goto T. Shimizu R. Miyabe K. Hashi H. Kitazawa G. Kido K. Shimamura T. Fukuda 《Applied Physics A: Materials Science & Processing》2002,74(1):73-77
We have performed 7Li and 19F nuclear magnetic resonance (NMR) in two lithium fluorides BaLiF3 and YLiF4 to explore the possibility of a crystal NMR quantum computing device. We find that (1) both the absolute values and the angular
dependences of the line widths can primarily be accounted for by the nuclear dipolar fields, and (2) the spin–lattice relaxation
times are long enough for quantum computations. These characteristics indicate that these crystals can be possible candidates
for quantum computing devices. We also find that, in the perovskite structures like BaLiF3, magic angles are quite effective to diminish the nuclear dipole fields, which enables us to treat some nuclei as ‘isolated’.
We propose using this feature to create low-dimensional nuclear-spin networks in the crystals.
Received: 29 January 2001 / Accepted: 6 February 2001 / Published online: 3 April 2001 相似文献
70.