全文获取类型
收费全文 | 225篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学 | 134篇 |
晶体学 | 6篇 |
力学 | 6篇 |
数学 | 38篇 |
物理学 | 46篇 |
出版年
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 4篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 7篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1970年 | 8篇 |
1969年 | 1篇 |
1968年 | 8篇 |
1967年 | 5篇 |
1954年 | 1篇 |
1932年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有230条查询结果,搜索用时 31 毫秒
81.
Computer programs have been written for interactive, conversational searching through the accumulated files of the 'Mass Spectrometry Bulletin' published by the Mass Spectrometry Data Centre (MSDC). This family of programs is available for use as a part of the NIH/EPA Chemical Information System on a commercial computer network. 相似文献
82.
D.C. Colley S.S. Huq M. Jobes J.B. Kinson J. Milne P.M. Watkins I.S. Hughes J.W.P. McCormick R.M. Turnbull 《Nuclear Physics B》1974,69(2):205-219
Data are presented on a high mass resonance produced in 10 GeV/c K+p interactions. The mass and width of the resonance, determined by a maximum likelihood fit to the pπ+ spectrum in the final state K+pπ+π?, are 1895±15 MeV/c2230±50 MeV/c2 respectively. The differential cross sections, dσ/dt, for the quasi two-body final states K1(890)Δ(1236) and K1(890)Δ(1900) are well described by the one pion exchange model. In addition the moments of the Gottfried-Jackson angular distribution of the pπ+ system agree with those computed from on-shell π+p elastic scattering data. We conclude that the two final states are produced mainly by π exchange and associate the structure observed in the moments up to NH(6,0) in the 1900 MeV region with the Regge recurrence of the Δ(1236). The dominant decay mode of the resonance is Δ++(1900)→pπ+ but decays to pπ+π0 and nπ+π+ are also observed. Cross sections are determined for the production of the quasi two-body final states K1(890)Δ(1236), K1(890) Δ(1900), K1(1420)Δ(1236) and K1(1420)Δ(1900). 相似文献
83.
Tyan and Thomas (J. Multivariate Anal.5 (1975), 227–235), have given a characterization of a class of bivariate distributions which yields, as a special case, a characterization of a class of bivariate Poisson distributions. In this paper we develop an analogous characterization of a class of bivariate Poisson processes and give some properties and examples of such processes. 相似文献
84.
Leroy B. Townsendxs Richard L. Tolman Roland K. Robins George H. Milne 《Journal of heterocyclic chemistry》1976,13(6):1363-1364
The synthesis of 2-amino-7-(β-D-riholuranosyl)pyrrolo[2,3-d ]pyrimidin-4-one (7-deazaguanos-ine, a nucleoside Q and Q* analog, has been accomplished hy two independcnl routes. 相似文献
85.
86.
87.
A collaborative study was conducted on a method for the measurement of 11 low-level pesticide residues in soft drinks and sports drinks by liquid chromatography with tandem mass spectrometry. The pesticide residues determined in this study were alachlor, atrazine, butachlor, isoproturon, malaoxon, monocrotophos, methyl paraoxon, phorate, phorate sulfone, phorate sulfoxide, and 2,4-dichlorophenoxyacetic acid (2,4-D). Blind fortification solutions containing 3 different levels of pesticide residues were provided to 9 collaborating laboratories to create test samples at concentrations of 0, 0.1, and 0.5 microg/L with a 10-fold concentration for phorate in a total of 6 matrixes (2 colas, 1 diet cola, 1 clear lemon-lime soft drink, 1 orange soft drink, and 1 sports drink). Good qualitative performance of the method was demonstrated for all pesticide residues. Reproducibility relative standard deviation (RSDR) ranged from 7 to 151% for alachlor, atrazine, butachlor, isoproturon, malaoxon, monocrotophos, methyl paraoxon, phorate, phorate sulfone, phorate sulfoxide, and 2,4-D at the 0.1 microg/L level (1.0 microg/L for phorate). At 0.5 microg/L (5.0 microg/L for phorate), RSDR ranged from 9 to 57% for alachlor, atrazine, butachlor isoproturon, malaoxon, monocrotophos, methyl paraoxon, phorate, phorate sulfone, phorate sulfoxide, and 2,4-D in all matrixes. Repeatability relative standard deviation (RSDr), applicable to the diet cola and sports drink, ranged from 0 to 124% for the 11 pesticide residues at the 0.1 microg/L level (1.0 microg/L for phorate). At 0.5 microg/L (5.0 microg/L for phorate), RSDr ranged from 4 to 26%. Recoveries for the 11 pesticide residues in all matrixes ranged from 84 to 300% at the 0.1 microg/L level (1.0 microg/L for phorate) and from 66 to 127% at the 0.5 microg/L (5.0 microg/L for phorate) level. Coefficients of determination (r2) of the matrix-matched calibration curves were > or = 0.95. It is recommended that the method be accepted by AOAC as Official First Action with a limit of quantification of 0.5 microg/L for alachlor, atrazine, butachlor, isoproturon, malaoxon, methyl paraoxon, monocrotophos, phorate sulfone, phorate sulfoxide, and 2,4-D and 5.0 microg/L for phorate. 相似文献
88.
V. Scardaci A.G. Rozhin F. Hennrich W.I. Milne A.C. Ferrari 《Physica E: Low-dimensional Systems and Nanostructures》2007,37(1-2):115
We report the fabrication of high optical quality single wall carbon nanotube polyvinyl alcohol composites and their application in nanotube based photonic devices. These show a broad absorption of semiconductor tubes centred at 1.55 μm, the spectral range of interest for optical communications. The films are used as mode-lockers in an erbium doped fibre laser, achieving 700 fs mode-locked pulses. Raman spectroscopy shows no damage after a long time continuous laser operation. 相似文献
89.
Milne JE Storz T Colyer JT Thiel OR Dilmeghani Seran M Larsen RD Murry JA 《The Journal of organic chemistry》2011,76(22):9519-9524
A new convenient and scalable synthesis of phenylacetic acids has been developed via the iodide catalyzed reduction of mandelic acids. The procedure relies on in situ generation of hydroiodic acid from catalytic sodium iodide, employing phosphorus acid as the stoichiometric reductant. 相似文献
90.
Mariager SO Pressacco F Ingold G Caviezel A Möhr-Vorobeva E Beaud P Johnson SL Milne CJ Mancini E Moyerman S Fullerton EE Feidenhans'l R Back CH Quitmann C 《Physical review letters》2012,108(8):087201
We use time-resolved x-ray diffraction and magneto-optical Kerr effect to study the laser-induced antiferromagnetic to ferromagnetic phase transition in FeRh. The structural response is given by the nucleation of independent ferromagnetic domains (τ(1)~30 ps). This is significantly faster than the magnetic response (τ(2)~60 ps) given by the subsequent domain realignment. X-ray diffraction shows that the two phases coexist on short time scales and that the phase transition is limited by the speed of sound. A nucleation model describing both the structural and magnetic dynamics is presented. 相似文献