全文获取类型
收费全文 | 125篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
化学 | 71篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 32篇 |
物理学 | 15篇 |
无线电 | 11篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 15篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 4篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1959年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有131条查询结果,搜索用时 0 毫秒
71.
Berg S Melamies M Rajamäki M Vainio O Peltonen K 《Analytical and bioanalytical chemistry》2012,402(3):1209-1215
A sensitive and selective method to quantify budesonide in dog plasma samples was developed and fully validated. Liquid–liquid
extraction was followed by solid-phase extraction and liquid chromatography–tandem mass spectrometry with electrospray ionization.
After reconstitution of the analytes in the mobile phase, samples were analysed by reversed-phase liquid chromatography with
isocratic elution. d8-Budesonide was used as an internal standard, and characteristic transitions of d8-budesonide and budesonide
were used for quantification. The method was validated with respect to selectivity, specificity, linearity, recovery, repeatability,
reproducibility and limits of detection and quantification. The validated method was successfully applied to monitor the plasma
levels of budesonide in dogs exposed to clinical doses of inhaled and intravenous drug. 相似文献
72.
We have computed vibrational high-frequency overtone spectra of the water-ammonia complex, H(2)O-NH(3), and its isotopomers. The complex has been modeled as two independently vibrating monomer units. The internal coordinate Hamiltonians for each monomer unit have been constructed using exact gas phase kinetic energy operators. The potential energy and dipole moment surfaces have been calculated with the explicitly correlated coupled cluster method CCSD(T)-F12A and the valence triple-ζ VTZ-F12 basis around the equilibrium geometry of the complex. The vibrational eigenvalues have been calculated variationally and the eigenfunctions obtained have been used to compute the intensities of the absorption transitions. In H(2)O-NH(3), the water molecule acts as the proton donor and its symmetry is broken. The hydrogen-bonded OH bond oscillator undergoes a large redshift and intensity enhancement compared to the free hydrogen bond. Broken degeneracy of the asymmetric vibrations, quenched inversion splittings, and blueshift of the symmetric bending mode are the most visible changes in the ammonia unit. 相似文献
73.
Xiaoxue Zhang Mari Honkanen Mikael Jrn Jouko Peltonen Viljami Pore Erkki Levnen Tapio Mntyl 《Applied Surface Science》2008,254(16):5129-5133
Boehmite thin film with 50–100 nm surface flake structure has been synthesized on AISI 316 type austenitic stainless steel by immersing boehmite gel film into boiling water. When further coated with hydrolyzed (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trimethoxysilane (FAS), the boehmite film becomes superhydrophobic with a contact angle for water of 152°. The superhydrophobic property results from both the nanoscale surface flake structure and the low surface energy of the FAS top layer. The topography of such film was revealed by atomic force microscope (AFM) and a set of roughness parameters of such film was discussed. The degradation of superhydrophobicity of the surface was studied as a function of the heat-treatment temperatures. Below 600 °C, the surface remained to be superhydrophobic with the FAS top layer. Above 700 °C, the surface was not superhydrophobic anymore due to a gradual loss in surface roughness which was revealed by field emission scanning electron microscope (FESEM). A phase change from boehmite to γ-Al2O3 occurred during the heat-treatments from 700 to 900 °C which was studied by the selected area electron diffraction (SAED) patterns from the transmission electron microscope (TEM) measurement. 相似文献
74.
Teemu Lukkari 《manuscripta mathematica》2010,132(3-4):463-482
We study regularity properties of weak solutions to elliptic equations involving variable growth exponents. We prove the sufficiency of a Wiener type criterion for the regularity of boundary points. This criterion is formulated in terms of the natural capacity involving the variable growth exponent. We also prove the Hölder continuity of weak solutions up to the boundary in domains with uniformly fat complements, provided that the boundary values are Hölder continuous. 相似文献
75.
Gaven Martin Volker Mayer Kirsi Peltonen 《Proceedings of the American Mathematical Society》2006,134(7):2091-2097
A uqr mapping of an -manifold is a mapping which is rational with respect to a bounded measurable conformal structure on . Remarkably, the only closed manifolds on which locally (but not globally) injective uqr mappings act are Euclidean space forms. We further characterize space forms admitting uniformly quasiregular self mappings and we show that the space forms admitting branched uqr maps are precisely the spherical space forms. We further show that every non-injective uqr map of a Euclidean space form is a quasiconformal conjugate of a conformal map. This is not true if the non-injective hypothesis is removed.
76.
This paper derives a new splitting-based decomposition algorithm for convex stochastic programs. It combines certain attractive
features of the progressive hedging algorithm of Rockafellar and Wets, the dynamic splitting algorithm of Salinger and Rockafellar
and an algorithm of Korf. We give two derivations of our algorithm. The first one is very simple, and the second one yields
a preconditioner that resulted in a considerable speed-up in our numerical tests.
The first author was supported by the Finnish Foundation for Economic Education under grants 20728 and 21599, and by Jenny
ja Antti Wihuri Foundation. 相似文献
77.
78.
Lauri Toikkanen Teemu Hakkarainen Andreas Schramm Antti Tukiainen Pekka Laukkanen Mircea Guina 《Journal of Crystal Growth》2010,312(21):3105-3110
Optical and structural properties of tensile strained graded GaxIn1−xP buffers grown on GaAs substrate have been studied by photoluminescence, X-ray diffraction, atomic force microscopy, and scanning electron microscopy measurements. The Ga composition in the graded buffer layers was varied from x=0.51 (lattice matched to GaAs) to x=0.66 (1% lattice mismatch to GaAs). The optimal growth temperature for the graded buffer layer was found to be about 80–100 °C lower than that for the lattice matched GaInP growth. The photoluminescence intensity and surface smoothness of the Ga0.66In0.34P layer grown on top of the graded buffer were strongly enhanced by temperature optimization. The relaxation of tensile GaInP was found to be highly anisotropic. A 1.5 μm thick graded buffer led to a 92% average relaxation and a room temperature photoluminescence peak wavelength of 596 nm. 相似文献
79.
Shan J Chen J Nuopponen M Viitala T Jiang H Peltonen J Kauppinen E Tenhu H 《Langmuir : the ACS journal of surfaces and colloids》2006,22(2):794-801
Amphiphilic thermally responsive gold nanoparticles have been prepared by protecting the particles with both polystyrene, PS, and poly(N-isopropylacrylamide), PNIPAM, chains. Particles form a monolayer on a water surface in a Langmuir trough, and according to in situ spectroscopic measurements, the surface plasmon resonance, SPR, band undergoes a blue-shift during the monolayer compression. The compression-induced blue-shift is related to a change in the conformation of tethered PNIPAM chains; the phenomenon is discussed on the basis of Mie-Drude theory. In contrast, a red-shift in the SPR of the multilayers of the same nanoparticles transferred at different temperatures has been observed with increasing the deposition cycle, attributed to the presence of a weak interparticle coupling in the multilayer. 相似文献
80.