全文获取类型
收费全文 | 110篇 |
免费 | 2篇 |
专业分类
化学 | 48篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 4篇 |
物理学 | 58篇 |
出版年
2020年 | 1篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 7篇 |
2011年 | 12篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1984年 | 2篇 |
1976年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有112条查询结果,搜索用时 31 毫秒
21.
Jussi Lehtola Mikko Hakala Arto Sakko Keijo Hämäläinen 《Journal of computational chemistry》2012,33(18):1572-1585
ERKALE is a novel software program for computing X‐ray properties, such as ground‐state electron momentum densities, Compton profiles, and core and valence electron excitation spectra of atoms and molecules. The program operates at Hartree–Fock or density‐functional level of theory and supports Gaussian basis sets of arbitrary angular momentum and a wide variety of exchange‐correlation functionals. ERKALE includes modern convergence accelerators such as Broyden and ADIIS and it is suitable for general use, as calculations with thousands of basis functions can routinely be performed on desktop computers. Furthermore, ERKALE is written in an object oriented manner, making the code easy to understand and to extend to new properties while being ideal also for teaching purposes. © 2012 Wiley Periodicals, Inc. 相似文献
22.
23.
24.
25.
Ullastiina Hakala 《Tetrahedron letters》2006,47(47):8375-8378
A microwave-promoted synthesis of polyhydroxydeoxybenzoins and -phenylpropanones has been developed, using bis{(trifluoromethyl)sulfonyl}amine (HNTf2) or BF3·OEt2 in an ionic liquid solvent. 相似文献
26.
Kati S. Hakala Marek Link Barbora Szotakova Lenka Skalova Risto Kostiainen Raimo A. Ketola 《Analytical and bioanalytical chemistry》2009,393(4):1327-1336
Liquid chromatography–ion trap mass spectrometry was used for the detection and structural characterization of metabolites
of the anti-obesity drug sibutramine. Metabolites were profiled from incubations of sibutramine in primary cultures of rat
hepatocytes. In addition, enantioselectivity of sibutramine metabolism was investigated by carrying out separate incubations
with (R)- and (S)-sibutramine. As a result, biotransformation profile for sibutramine with rat hepatocytes is proposed. Nineteen metabolites
and several of their isomers formed via demethylation, hydroxylation, dehydrogenation, acetylation, attachment of CO2, and glucuronidation were identified in MS2 and MS3 experiments, though the exact position of the functionality, mostly hydroxylation, could not always be determined from the
mass spectrometric information. However, clear enantioselective formation was observed for two hydroxyl derivatives and two
glucuronide conjugates, indicating that the hydroxyl/glucuronic acid moiety in those structures is close to the chiral center.
Most of the metabolites found in this study are new metabolites of sibutramine, which were not previously reported. 相似文献
27.
Anne-Marja Uusitalo Tuula T. Pakkanen Minna Krger-Laukkanen Lauri Niinist Kimmo Hakala Santeri Paavola Barbro Lfgren 《Journal of molecular catalysis. A, Chemical》2000,160(2):343-356
Heterogeneous metallocene catalysts were prepared by adsorbing rac-Et(Ind)2ZrCl2 on a modified silica surface in solution. The modification of silica was conducted in gas phase with atomic layer chemical vapor deposition (ALCVD) technique, where the silica, preheated at either 350 or 600°C, was allowed to react with vaporized trimethylaluminum (TMA) at 250°C. Modified carriers and heterogeneous catalysts were characterized with FTIR, 1H MAS (magic-angle spinning) NMR, 13C, and 29Si CP (cross-polarization) MAS NMR spectroscopies and elemental analyses. In the reaction of TMA with silica, a saturated surface was formed consisting of different (---O)4−nSi(CH3)n (n=1, 2 or 3) and ---AlCH3 groups. The ratio of ---SiMe to ---AlMe groups was approximately 1.5 in the TMA/SiO2 carriers. When the metallocene was adsorbed onto the carrier it seemed to react with the surface ---AlCH3 groups and possibly ---ZrCH3 groups were formed. Heterogeneous catalysts were tested in the polymerization of ethylene and propylene in the presence of methylalumoxane (MAO). And they produced similar polymer as the homogeneous rac-Et(Ind)2ZrCl2 catalyst, but with lower activity. A catalyst with the best activity was achieved from silica that was preheated at 600°C. Moreover, leaching of catalyst was examined whereupon a part of zirconium was observed to desorb from the carrier. 相似文献
28.
J. Kurpeta V. -V. Elomaa T. Eronen J. Hakala A. Jokinen P. Karvonen I. Moore H. Penttilä A. Płochocki S. Rahaman S. Rinta-Antila J. Rissanen J. Ronkainen A. Saastamoinen T. Sonoda W. Urban Ch. Weber J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):263-266
Exotic, neutron-rich 111Mo and 115Ru nuclei, produced in proton-induced fission of 238U target, were separated with the IGISOL mass separator. The separator was coupled to the JYFLTRAP Penning trap to select
the ions of a single, desired element out of the isobaric IGISOL beam. Monoisotopic samples of 115Ru and 111Mo ions were observed with a microchannel plate detector after the trap or were implanted on a catcher foil for gamma- and
beta-ray coincidence spectroscopy. In spite of short data taking time new gamma transitions were identified in the beta decay
of very neutron-rich 115Ru. 相似文献
29.
30.
Lei Shi Xiaowen Yuan Yafeng Zhang Tommi Hakala Shaoyu Yin Dezhuan Han Xiaolong Zhu Bo Zhang Xiaohan Liu Pivi Trm Wei Lu Jian Zi 《Laser \u0026amp; Photonics Reviews》2014,8(5):717-725
The spatial and temporal coherence of the fluorescence emission controlled by a quasi‐two‐dimensional hybrid photonic–plasmonic crystal structure covered with a thin fluorescent‐molecular‐doped dielectric film is investigated experimentally. A simple theoretical model to describe how a confined quasi‐two‐dimensional optical mode may induce coherent fluorescence emission is also presented. Concerning the spatial coherence, it is experimentally observed that the coherence area in the plane of the light source is in excess of 49 μm2, which results in enhanced directional fluorescence emission. Concerning temporal coherence, the obtained coherence time is 4 times longer than that of the normal fluorescence emission in vacuum. Moreover, a Young's double‐slit interference experiment is performed to directly confirm the spatially coherent emission. This smoking gun proof of spatial coherence is reported here for the first time for the optical‐mode‐modified emission. 相似文献