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101.
We establish conditions for boundedness of square means of the logarithms of Blaschke products.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 51, No. 2, pp. 255–259, February, 1999. 相似文献
102.
103.
S. Mudry T. Lutchyshyn Yu. Plevachuk V. Sklyarchuk 《Journal of Molecular Liquids》2005,120(1-3):99-102
Structure of Cu1−xPbx (x=0, 0.025, 0.05, 0.075, 0.1, 0.125) molten alloys has been studied by means of X-ray diffraction method. Structural parameters obtained from structure factors (SF) and radial distribution functions were analyzed. Partial structure factors were calculated by using Reverse Monte-Carlo method. It is shown that tendency to preferred interaction of atoms of the same kind grows with increasing of lead content. 相似文献
104.
Vasyl I. Zaremba Ute Ch. Rodewald Mar’yana Lukachuk Vitaliy P. Dubenskiy Birgit Heying Kenichi Katoh Yuzuru Niide Akira Ochiai Rainer Pöttgen 《Monatshefte für Chemie / Chemical Monthly》2006,137(3):249-261
Summary. The rare earth–transition metal-indides GdPdIn, ErPdIn, YbPdIn, YPtIn, TmPtIn, Dy4Pd10In21, PrPt2In2, and Tb2Pt7In16 were prepared by arc-melting of the elements or by induction melting of the elements in sealed tantalum tubes in a water-cooled
sample chamber of a high-frequency furnace. Single crystals of Dy4Pd10In21 and Tb2Pt7In16 were grown through special annealing procedures. The indides were investigated via X-ray powder diffraction and all structures were refined from X-ray single crystal diffractometer data: ZrNiAl type,
, a = 767.8(3), c = 390.7(2) pm, wR2 = 0.0722, 356 F2 values for GdPdIn; a = 766.7(3), c = 376.7(1) pm, wR2 = 0.0433, 348 F2 values for ErPdIn; a = 757.2(2), c = 393.59(8) pm, wR2 = 0.0388, 434 F2 values for YbPdIn; a = 758.2(2), c = 384.95(8) pm, wR2 = 0.0643, 353 F2 values for YPtIn; and a = 753.4(1), c = 376.71(4) pm, wR2 = 0.0844, 310 F2 values for TmPtIn, with 14 variable parameters per refinement. Dy4Pd10In21 crystallizes with the monoclinic Ho4Ni10Ga21 structure: C2/m, a = 2284.5(8), b = 441.0(2), c = 1931.4(7) pm, β = 132.74(2)°, wR2 = 0.0419, 1690 F2 values, 112 variable parameters. PrPt2In2 adopts the CePt2In2 type: P21/m, a = 1013.2(3), b = 447.2(3), c = 1019.5(3) pm, β = 116.69(2)°, wR2 = 0.0607, 1259 F2 values, 63 variable parameters. Tb2Pt7In16 is the second representative of the orthorhombic Dy2Pt7In16 type: Cmmm, a = 1211.6(2), b = 1997.1(4), c = 440.52(9) pm, wR2 = 0.0787, 1341 F2 values, 45 variable parameters. The common structural motif of the four different structure types are transition metal centered
trigonal prisms formed by the rare earth metal and indium atoms. These prisms are condensed via common corners or via In–In bonds. The crystal chemistry of the four different structure types is discussed. 相似文献
105.
Vasyl Kuryliuk Artem Podolian Oleg Korotchenkov 《Central European Journal of Physics》2010,8(1):65-76
We demonstrate a method of using a two-layer sandwich structure, which includes a LiNbO3 plate and a semiconductor heterostructure to create an inhomogeneous stress and piezoelectric harmonic potential in the semiconductor.
Both the GaAs/AlGaAs quantum well (QW) structures and SiGe/Si heterostructures are attempted, working with and without using
a piezoelectric field in the semiconductor layer. The standing-wave fields generated in the semiconductor and the electron
and hole distributions driven by the piezoelectric field are computed by finite element method (FEM) techniques. It is experimentally
shown that, in a GaAs/AlxGa1-x
As asymmetric double quantum well structure, the resonance enhancement of the narrower QW photoluminescence band is observed,
which may be explained by the resonant charge transfer between the wider and narrower QWs. It is also shown that the piezoelectric
fields quench the pure LO-phonon lines in the Raman spectra, whereas the coupled LO-phonon-plasmon mode strengthens. Experimental
results indicate that the charge separation occurs in the plane of the QWs due to the piezoelectric fields. The recombination
of carriers in the SiGe/Si heterostructures can be effectively enhanced by the presence of ultrasonic stress, displaying features
consistent with varying electrical activity at dislocations. 相似文献
106.
Cedrik Meier Stephan Lüttjohann Vasyl G. Kravets Hermann Nienhaus Axel Lorke Hartmut Wiggers 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):155
The Raman spectra of silicon nanoparticles in the size range between d=3.5– have been studied experimentally. Scattering processes up to second order are being observed. The experimental results are analyzed in the framework of the phonon confinement model. While this model describes qualitatively the observations for first-order scattering processes, it is not applicable for scattering processes of higher order. From the analysis of second-order scattering, we determine a redshift of the TO phonon at the X and L points. 相似文献
107.
Vasyl Ostrovskyi Daniil Proskurin Lyudmila Turowska 《Letters in Mathematical Physics》2008,85(2-3):147-162
We study a deformation of the Cuntz–Toeplitz C *-algebra determined by the relations ${a_i^*a_i=1+q a_ia_i^*,\, a_i^*a_j=0}$ . We define its well-behaved unbounded *-representations and classify all irreducible ones up to unitary equivalence. 相似文献
108.
The influence of low molecular weight cryoprotectants (CPs) such as glycerol (GL), 1,2-propanediol (PD) and dimethylsulfoxide
(DMSO) on the structure of rat liver microsomal membranes on the stages of equilibration and upon freezing up to −196°C was
studied using a multiparametric fluorescent probe of flavonol nature. It was estimated that the studied CPs have individual
concentration ranges defining low amplitude of their action on biomembranes. An exceeding of these ranges strongly increases
the violation of membrane native structure already at the stage of incubation with CPs, strengthening it during the freezing
procedure. According to the perturbation effect on microsomal membranes the studied CPs can be arranged in a sequence: DMSO
> PD > GL. 相似文献
109.
The isotypic indides RE4Pt10In21 (RE = La, Ce, Pr, Nd) were prepared by melting mixtures of the elements in an arc‐furnace under an argon atmosphere. Single crystals were synthesized in tantalum ampoules using special temperature modes. The four samples were studied by powder and single crystal X‐ray diffraction: Ho4Ni10Ga21 type, C2/m, a = 2305.8(2), b = 451.27(4), c = 1944.9(2) pm, β = 133.18(7)°, wR2 = 0.045, 2817 F2 values, 107 variables for La4Pt10In21, a = 2301.0(2), b = 448.76(4), c = 1941.6(2) pm, β = 133.050(8)°, wR2 = 0.056, 3099 F2 values, 107 variables for Ce4Pt10In21, a = 2297.4(2), b = 447.4(4), c = 1939.7(2) pm, β = 132.95(1)°, wR2 = 0.059, 3107 F2 values, 107 variables for Pr4Pt10In21, and a = 2294.7(4), b = 446.1(1), c = 1938.7(3) pm, β = 132.883(9)°, wR2 = 0.067, 2775 F2 values, 107 variables for Nd4Pt10In21. The 8j In2 positions of all structures have been refined with a split model. The In1 sites of the lanthanum and the cerium compound show small defects, leading to the refined composition La4Pt10In20.966(6) and Ce4Pt10In20.909(6) for the investigated crystals. The same position shows Pt/In mixing in the praseodymium and neodymium compound leading to the refined compositions Pr4Pt10.084(9)In20.916(9) and Nd4Pt10.050(9)In20.950(9). All platinum atoms have a tricapped trigonal prismatic coordination by rare‐earth metal and indium atoms. The shortest interatomic distances occur for Pt–In followed by In–In. Together, the platinum and indium atoms build up three‐dimensional [Pt10In21] networks in which the rare earth atoms fill distorted pentagonal tubes. The crystal chemistry of RE4Pt10In21 is discussed and compared with the RE4Pd10In21 indides and isotypic gallides. 相似文献
110.
Klymchenko AS Duportail G Ozturk T Pivovarenko VG Mély Y Demchenko AP 《Chemistry & biology》2002,9(11):1199-1208
3-hydroxyflavone (3-HF) derivatives are very attractive fluorescence sensors due to their ability to respond to small changes in their microenvironment via a dramatic alteration of the relative intensities of their two well-separated emission bands. We developed fluorescence probes with locations at different depths and orientations of 3-HF moiety in the phospholipid bilayer, which determine their fluorescence behavior. While the spectral shifts of the probes correlate with their binding site polarity, the intensity ratio is a complex parameter that is also sensitive to the local hydration. We demonstrate that even the deeply located probes sense this hydration effect, which can be modulated by the charge of the lipid heads and is anisotropic with respect to the bilayer plane. Thus the two-band ratiometric fluorescence probes can provide multiparametric information on the properties of lipid membranes at different depths. 相似文献