全文获取类型
收费全文 | 121篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 69篇 |
力学 | 3篇 |
物理学 | 51篇 |
出版年
2022年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 10篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1979年 | 2篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有123条查询结果,搜索用时 15 毫秒
81.
Adler S Atiya MS Chiang IH Diwan MV Frank JS Haggerty JS Jain V Kettell SH Kycia TF Li KK Littenberg LS Ng C Strand RC Witzig C Kazumori M Komatsubara TK Kuriki M Muramatsu N Otomo A Sugimoto S Inagaki T Kabe S Kobayashi M Kuno Y Sato T Shinkawa T 《Physical review letters》2000,84(17):3768-3770
A search for additional evidence for the rare kaon decay K+-->pi(+)nunu; has been made with a new data set comparable in sensitivity to the previous exposure that produced a single event. No new events were found in the pion momentum region examined, 211
pi(+)nunu;) = 1.5(+3.4)(-1.2)x10(-10). 相似文献
82.
83.
Fumio Hama Yoshiteru Sakata Soichi Misumi Misako Aida Chikayoshi Nagata 《Tetrahedron letters》1982,23(30):3061-3064
The structure of the title compound 1a was determined to be a cross-stacking form with an interplanar distance of ca. 3.3 Å by X-ray analysis. On the basis of this structure, the hypochromicity of 1a was calculated by the ASMO SCF CI method. 相似文献
84.
A structural transition from f.c.c. to b.c.c. is suggested to occur for solid Xe at high pressure. This phase transition is shown to precede the metallization, and accordingly brings about a metallization pressure 0.82 Mbar which is closer to the experimental value 0.33 Mbar than the previous estimate 1.30 Mbar with f.c.c. as the assumed structure. The first-order effect of the spin-orbit coupling is also studied with an improved transition pressure 0.66 Mbar. These studies have been done consistently by means of the APW method combined with the local-density scheme. 相似文献
85.
Takao Yamazaki Hiroki Takahata Yoko Hama Yoshiaki Takano Masanori Nagata Raymond N. Castle 《Journal of heterocyclic chemistry》1979,16(3):525-526
The condensation of 1-aminoethyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 1 with 1,2-cyclohexanedione 2 gave the 8,12-diaza- D -homosteroid system 3 , which was reduced with Adams' catalyst followed by acetic anhydride acetylation to afford the 8,12-diaza- D -homosteroids 4a,b . 相似文献
86.
Production of gaseous OH radicals in the 248-350 nm photoirradiation of NO3(-) doped on amorphous ice at 100 K was monitored directly by using resonance-enhanced multiphoton ionization. The translational energy distribution of the OH product was represented by a Maxwell-Boltzmann energy distribution with the translational temperature of 3250 +/- 250 K. The rotational temperature was estimated to be 175 +/- 25 K. We have confirmed that the OH production should be attributed to the secondary photolysis of H2O2 produced on ice surface on the basis of the results of controlled photolysis experiments for H2O2 doped on ice surface. 相似文献
87.
Bassolé IH Lamien-Meda A Bayala B Tirogo S Franz C Novak J Nebié RC Dicko MH 《Molecules (Basel, Switzerland)》2010,15(11):7825-7839
Essential oils from leaves of Lippia multiflora, Mentha x piperita and Ocimum basilicum from Burkina Faso were analysed by GC-FID and GC-MS. Major components were p-cymene, thymol, b-caryophyllene, carvacrol and carvone for L. multiflora, menthol and iso-menthone for M. x piperita and, linalool and eugenol for O. basilicum. The essential oils and their major monoterpene alcohols were tested against nine bacterial strains using the disc diffusion and broth microdilution methods. The essential oils with high phenolic contents were the most effective antimicrobials. The checkerboard method was used to quantify the efficacy of paired combinations of essential oils and their major components. The best synergetic effects among essential oils and major components were obtained with combinations involving O. basilicum essential oil and eugenol, respectively. As phenolic components are characterized by a strong spicy aroma, this study suggests that the selection of certain combinations of EOs could help to reduce the amount of essential oils and consequently reduce any adverse sensory impact in food. 相似文献
88.
R. Andrade A. dos Reis F. Grassi Y. Hama T. Kodama J. -Y. Ollitrault W. -L. Qian 《Indian Journal of Physics》2010,84(12):1657-1661
Hydrodynamics has been rather successful at describing results obtained in relativistic nuclear collisions at RHIC. Here we
show results obtained with NeXSPheRIO on Au+Au collisions and the less studied Cu+Cu collisions. We study elliptic flow and
its connection with eccentricity suggested by PHOBOS, as well as present elliptic flow fluctuations. We also show results
for directed flow and compare with PHOBOS and STAR data. 相似文献
89.
New fluorescent ionophores containing the 1-naphthylacetanilide moiety based on oligo-ethylene oxide (1(4) and 1(5)) have been synthesized, and their photochemical behaviors have been studied. In the absence of a metal ion, the 1-naphthylacetanilide moiety showed a weak fluorescence emission (fluorescence "off state"). However, complexation with Ca(2+) induced a large enhancement effect on the fluorescence intensity of 1(4) and 1(5) from the naphthalene ring (fluorescence "on" state). This behavior can be explained in terms of a similar twisted intramolecular charge-transfer relaxation mechanism. Such "off-on" fluorescence responses of 1(4) and 1(5) provide the digital detection of alkaline earth metal ions. 相似文献
90.
Murphy JM Lawrence JD Kawamura K Incarvito C Hartwig JF 《Journal of the American Chemical Society》2006,128(42):13684-13685
We report the regiospecific, ruthenium-catalyzed borylation of saturated terminal C-H bonds. Alkylboronates were obtained in 78-98% yields. The borylations of alkanes, trialkylamines, protected alcohols, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. In contrast to most organometallic C-H activation, the reactions of alkanes occurred in higher yields than the reactions of arenes. Reactions were conducted that probed steric and electronic effects on the alkyl borylation. These reactions showed that the borylation occurred preferentially at the methyl group that is least sterically hindered and most electron-deficient. Ruthenium compounds containing boryl ligands were synthesized, and one was characterized by X-ray crystallography. One of these compounds contained a rare bridging boryl ligand and served as a catalyst precursor for the borylation of octane. 相似文献