全文获取类型
收费全文 | 129篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学 | 48篇 |
晶体学 | 1篇 |
力学 | 6篇 |
数学 | 34篇 |
物理学 | 41篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2015年 | 1篇 |
2013年 | 8篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 15 毫秒
31.
Perepichka DF Bryce MR Batsanov AS McInnes EJ Zhao JP Farley RD 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(20):4656-4669
Novel R3TTF-sigma-A compounds 14, 16 and 19 (R3TTF = trial-kyletrathiafulvalene, sigma = saturated spacer, A = polynitrofluoren-9-dicyano-methylene acceptor) incorporating very strong donor and acceptor moieties have been synthesized by condensation of the corresponding R3TTF-sigma-fluoren-9-one diads with malononitrile. Reversible five-step amphoteric redox behavior has been observed with an extremely low HOMO-LUMO gap (approximately 0.3 eV). For compound 14 a strong EPR signal is observed in the solid state, ascribed to intermolecular complexation: a less intense signal is seen in solution, corresponding to ca. 2% of the molecules existing in a radical form at room temperature. Intramolecular charge transfer in diads 14 and 16 is manifested in strong absorption bands in the near-IR region of their electronic spectra. Spectroelectrochemical data reveal marked electrochromic behavior in the visible and near-IR region of both compounds. The first X-ray crystal structure of a fluorene radical-anion salt is reported, namely the copper salt of 2,4,5,7-tetranitro-9- dicyanomethylenefluorene (1:1 stoichiometry). 相似文献
32.
33.
Ideals of Priestley powers of semilattices 总被引:1,自引:0,他引:1
J. D. Farley 《Algebra Universalis》1999,41(4):239-254
Let X be a poset and Y an ordered space; X
Y
denotes the poset of continuous order-preserving maps from Y to X with the discrete (respectively, Scott, Lawson) topology. If S is a -semilattice, its ideal semilattice, and T a bounded distributive lattice with Priestley dual space P(T), it is shown that the following isomorphisms hold: Moreover, and sufficient conditions and necessary conditions for the isomorphism to hold are obtained (both necessary and sufficient
if S is a distributive -semilattice).
Received September 27, 1995; accepted in final form April 6, 1998. 相似文献
34.
David S. Campbell Andrew V. Chapman Paul S. Farley 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):475-476
Abstract Vulcanizates containing only di- and poly-suiphidic crosslinks can be transformed into soluble rubber by treatment with hexane-1-thiol/piperidine, enabling examination of the crosslink sites by 1H NMR spectroscopy in solution. 相似文献
35.
A graph G = (V, E) is matching immune if there is no matching cut in G. We show that for any matching immune graph G, |E|≥?3(|V|?1)/2?. This bound is tight, as we define operations that construct, from a given vertex, exactly the class of matching immune graphs that attain the bound. © 2011 Wiley Periodicals, Inc. J Graph Theory 69:206‐222, 2012 . 相似文献
36.
Brumley WC Grange AH Kelliher V Patterson DB Montcalm A Glassman J Farley JW 《Journal of AOAC International》2000,83(5):1059-1067
37.
Bennett GW Bousquet B Brown HN Bunce G Carey RM Cushman P Danby GT Debevec PT Deile M Deng H Deninger W Dhawan SK Druzhinin VP Duong L Efstathiadis E Farley FJ Fedotovich GV Giron S Gray FE Grigoriev D Grosse-Perdekamp M Grossmann A Hare MF Hertzog DW Huang X Hughes VW Iwasaki M Jungmann K Kawall D Khazin BI Kindem J Krienen F Kronkvist I Lam A Larsen R Lee YY Logashenko I McNabb R Meng W Mi J Miller JP Morse WM Nikas D Onderwater CJ Orlov Y Ozben CS Paley JM Peng Q Polly CC Pretz J Prigl R 《Physical review letters》2002,89(10):101804
A higher precision measurement of the anomalous g value, a(mu)=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a(mu(+))=11 659 204(7)(5)x10(-10) (0.7 ppm) is in good agreement with previous measurements and has an error about one-half that of the combined previous data. The present world average experimental value is a(mu)(expt)=11 659 203(8)x10(-10) (0.7 ppm). 相似文献
38.
Bennett GW Bousquet B Brown HN Bunce G Carey RM Cushman P Danby GT Debevec PT Deile M Deng H Deninger W Dhawan SK Druzhinin VP Duong L Efstathiadis E Farley FJ Fedotovich GV Giron S Gray FE Grigoriev D Grosse-Perdekamp M Grossmann A Hare MF Hertzog DW Huang X Hughes VW Iwasaki M Jungmann K Kawall D Kawamura M Khazin BI Kindem J Krienen F Kronkvist I Lam A Larsen R Lee YY Logashenko I McNabb R Meng W Mi J Miller JP Mizumachi Y Morse WM Nikas D Onderwater CJ Orlov Y Ozben CS Paley JM Peng Q 《Physical review letters》2008,100(9):091602
The spin precession frequency of muons stored in the (g-2) storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for a nonzero delta omega a(=omega a mu+ - omega a mu-) and a sidereal variation of omega a mu+/-). No significant effect is found, and the following limits on the standard-model extension parameters are obtained: bZ = -(1.0+/-1.1) x 10(-23) GeV; (m mu dZ0 + HXY)=(1.8+/-6.0) x 10(-23) GeV; and the 95% confidence level limits b perpendicular mu+ <1.4 x 10(-24) GeV and b perpendicular mu- <2.6 x 10(-24) GeV. 相似文献
39.
Frank W. Crow Wayne K. Duholke Chad E. Hadden Richard F. Smith Thomas J. Thamann Brian D. Kaluzny David A. Hahn Christopher S. Mallory Kathleen A. Farley Gary E. Martin 《Journal of heterocyclic chemistry》1999,36(2):365-370
The rigorous structural characterization of novobiocin, is reported using mass spectrometric, infrared and nmr spectroscopic analysis. Complete nmr assignments are reported. Previous reports in the literature had left some quaternary carbon resonances unassigned. Isonovobiocin and decarbamylnovobiocin, although known in the literature for a number of years, have never been completely characterized. Mass spectrometric fragmentation pathways and complete 1H and 13C nmr assignments are reported for these congeners for the first time. The mass spectral fragmentation pathway and nmr assignments are also reported for 2″-(O-carbamyl)novobiocin although the nmr assignments at lower field were reported previously. The structural characterization of novobiocin-2″,3″-carbonate observed in the Test Assay procedure used for Novobiocin is reported for the first time. 相似文献
40.
Edmonds KW Bogusławski P Wang KY Campion RP Novikov SN Farley NR Gallagher BL Foxon CT Sawicki M Dietl T Buongiorno Nardelli M Bernholc J 《Physical review letters》2004,92(3):037201
We present a combined theoretical and experimental study of the ferromagnetic semiconductor (Ga,Mn)As which explains the remarkably large changes observed on low-temperature annealing. Careful control of the annealing conditions allows us to obtain samples with ferromagnetic transition temperatures up to 159 K. Ab initio calculations, in situ Auger spectroscopy, and resistivity measurements during annealing show that the observed changes are due to out diffusion of Mn interstitials towards the surface, governed by an energy barrier of 0.7-0.8 eV. Electric fields induced by Mn acceptors have a significant effect on the diffusion. 相似文献